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  • 1.
    Abdullah, Gamil M. S.
    et al.
    Department of Civil Engineering, College of Engineering, Najran University, P.O. 1988, Najran, Saudi Arabia.
    Ahmad, Mahmood
    Institute of Energy Infrastructure, Universiti Tenaga Nasional, 43000, Kajang, Malaysia; Department of Civil Engineering, University of Engineering and Technology Peshawar (Bannu Campus), Bannu, 28100, Pakistan.
    Babur, Muhammad
    Department of Civil Engineering, Faculty of Engineering, University of Central Punjab, Lahore, 54000, Pakistan.
    Badshah, Muhammad Usman
    Water Wing, Water and Power Development Authority (WAPDA), WAPDA House Peshawar, Peshawar, 25000, Pakistan.
    Al-Mansob, Ramez A.
    Department of Civil Engineering, Faculty of Engineering, International Islamic University Malaysia, Jalan Gombak, 50728, Selangor, Malaysia.
    Gamil, Yaser
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Department of Civil Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia.
    Fawad, Muhammad
    Silesian University of Technology, Gliwice, Poland; Budapest University of Technology and Economics, Budapest, Hungary.
    Boosting-based ensemble machine learning models for predicting unconfined compressive strength of geopolymer stabilized clayey soil2024In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 2323Article in journal (Refereed)
    Abstract [en]

    The present research employs new boosting-based ensemble machine learning models i.e., gradient boosting (GB) and adaptive boosting (AdaBoost) to predict the unconfined compressive strength (UCS) of geopolymer stabilized clayey soil. The GB and AdaBoost models were developed and validated using 270 clayey soil samples stabilized with geopolymer, with ground-granulated blast-furnace slag and fly ash as source materials and sodium hydroxide solution as alkali activator. The database was randomly divided into training (80%) and testing (20%) sets for model development and validation. Several performance metrics, including coefficient of determination (R2), mean absolute error (MAE), root mean square error (RMSE), and mean squared error (MSE), were utilized to assess the accuracy and reliability of the developed models. The statistical results of this research showed that the GB and AdaBoost are reliable models based on the obtained values of R2 (= 0.980, 0.975), MAE (= 0.585, 0.655), RMSE (= 0.969, 1.088), and MSE (= 0.940, 1.185) for the testing dataset, respectively compared to the widely used artificial neural network, random forest, extreme gradient boosting, multivariable regression, and multi-gen genetic programming based models. Furthermore, the sensitivity analysis result shows that ground-granulated blast-furnace slag content was the key parameter affecting the UCS.

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  • 2.
    Ahmed, Dooraid N.
    et al.
    Department of Mathematics, College of Education for Pure Sciences, University of Kirkuk, Kirkuk, Iraq.
    Naji, Laith A.
    Department of Environmental Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.
    Faisal, Ayad A. H.
    Department of Environmental Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Naushad, Mu.
    Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
    Waste foundry sand/MgFe-layered double hydroxides composite material for efficient removal of Congo red dye from aqueous solution2020In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, p. 1-12, article id 2042Article in journal (Refereed)
    Abstract [en]

    We aimed to obtain magnesium/iron (Mg/Fe)-layered double hydroxides (LDHs) nanoparticles-immobilized on waste foundry sand-a byproduct of the metal casting industry. XRD and FT-IR tests were applied to characterize the prepared sorbent. The results revealed that a new peak reflected LDHs nanoparticles. In addition, SEM-EDS mapping confirmed that the coating process was appropriate. Sorption tests for the interaction of this sorbent with an aqueous solution contaminated with Congo red dye revealed the efficacy of this material where the maximum adsorption capacity reached approximately 9127.08 mg/g. The pseudo-first-order and pseudo-second-order kinetic models helped to describe the sorption measurements, indicating that the physical and chemical forces governed the removal process.

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  • 3.
    Ahmed, Naeem
    et al.
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
    Siow, Kim S.
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
    Wee, M. F. Mohd Razip
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
    Patra, Anuttam
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    A study to examine the ageing behaviour of cold plasma-treated agricultural seeds2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 1675Article in journal (Refereed)
    Abstract [en]

    Cold plasma (low pressure) technology has been effectively used to boost the germination and growth of various crops in recent decades. The durability of these plasma-treated seeds is essential because of the need to store and distribute the seeds at different locations. However, these ageing effects are often not ascertained and reported because germination and related tests are carried out within a short time after the plasma-treatment. This research aims to fill that knowledge gap by subjecting three different types of seeds (and precursors): Bambara groundnuts (water), chilli (oxygen), and papaya (oxygen) to cold plasma-treatment. Common mechanisms found for these diverse seed types and treatment conditions were the physical and chemical changes induced by the physical etching and the cold plasma on the seeds and subsequent oxidation, which promoted germination and growth. The high glass transition temperature of the lignin-cellulose prevented any physical restructuring of the surfaces while maintaining the chemical changes to continue to promote the seeds germination and growth. These changes were monitored over 60 days of ageing using water contact angle (WCA), water uptake, electrical conductivity, field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The vacuum effect was also investigated to separate its effect from cold plasma (low pressure). This finding offers a framework for determining how long agricultural seeds that have received plasma treatment can be used. Additionally, there is a need to transfer this research from the lab to the field. Once the impact of plasma treatment on seeds has been estimated, it will be simple to do so.

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  • 4.
    Akhtar, Farid
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, 10691, Sweden.
    Ogunwumi, Steven
    Crystalline Materials Research, Corning Incorporated, Corning, New York, USA.
    Bergström, Lennart
    Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, 10691, Sweden.
    Thin zeolite laminates for rapid and energy-efficient carbon capture2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, article id 10988Article in journal (Refereed)
    Abstract [en]

    Thin, binder-less zeolite NaX laminates, with thicknesses ranging between 310 to 750 μm and widths exceeding 50 mm and biaxial tensile strength in excess of 3 MPa, were produced by pulsed current processing. The NaX laminates displayed a high CO2 adsorption capacity and high binary CO2-over-N2 and CO2-over-CH4 selectivity, suitable for CO2 capture from flue gas and upgrading of raw biogas. The thin laminates displayed a rapid CO2 uptake; NaX laminates with a thickness of 310 μm were saturated to 40% of their CO2 capacity within 24 seconds. The structured laminates of 310 μm thickness and 50 mm thickness would offer low pressure drop and efficient carbon capture performance in a laminate-based swing adsorption technology.

  • 5.
    Alvi, Sajid
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    High temperature tribology of polymer derived ceramic composite coatings2018In: Scientific Reports, E-ISSN 2045-2322, Vol. 8, article id 15105Article in journal (Refereed)
    Abstract [en]

    Polymer derived ceramic (PDC) composite coatings were deposited on AISI 304 substrates using siloxane based preceramic polymer polymethlysilsquioxane (PMS) and ZrSi2 as active filler or Ag as passive filler. The tribological performance of the composite coatings was evaluated at room temperature and moderately high temperatures (150 °C, 200 °C, 300 °C and 400 °C). The composite coatings showed low coefficient of friction (COF), µ, from 0.08 to 0.2 for SiOC-ZrSi2 composite coatings, and from 0.02 to 0.3 for SiOC-Ag composite coatings, at room temperature with increasing normal load from 1 to 5 N. High temperature tribology tests showed high COF values from 0.4 to 1 but low wear for SiOC-ZrSi2 coating, and low COF from 0.2 to 0.3 for SiOC-Ag coatings at lower temperature ranges. Low load friction tests at room temperature showed negligible wear in SiOC-ZrSi2 coatings, suggesting good wear resistant and lubricating properties due to formation of t-ZrO2 and carbon. Low COF and high amount of wear was observed in SiOC-Ag composite coatings at room temperature due to high ductility of Ag and smearing of wear debris in the wear track. The coatings and wear tracks were characterized to evaluate the lubrication and wear behavior.

  • 6.
    Andersson, Magnus
    et al.
    Department of Earth Sciences, Uppsala University.
    Malehmir, Alireza
    Department of Earth Sciences, Uppsala University.
    Troll, Valentin R.
    Department of Earth Sciences, Uppsala University.
    Dehghannejad, Mahdieh
    Department of Earth Sciences, Uppsala University.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carbonatite ring-complexes explained by caldera-style volcanism2013In: Scientific Reports, E-ISSN 2045-2322, Vol. 3, article id 1677Article in journal (Refereed)
    Abstract [en]

    Carbonatites are rare, carbonate-rich magmatic rocks that make up a minute portion of the crust only, yet they are of great relevance for our understanding of crustal and mantle processes. Although they occur in all continents and from Archaean to present, the deeper plumbing system of carbonatite ring-complexes is usually poorly constrained. Here, we show that carbonatite ring-complexes can be explained by caldera-style volcanism. Our geophysical investigation of the Alnö carbonatite ring-complex in central Sweden identifies a solidified saucer-shaped magma chamber at ∼3 km depth that links to surface exposures through a ring fault system. Caldera subsidence during final stages of activity caused carbonatite eruptions north of the main complex, providing the crucial element to connect plutonic and eruptive features of carbonatite magmatism. The way carbonatite magmas are stored, transported and erupt at the surface is thus comparable to known emplacement styles from silicic calderas.

  • 7.
    Azua-Bustos, Armando
    et al.
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain. Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile.
    González-Silva, Carlos
    Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile.
    Fernández-Martínez, Miguel Ángel
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Arenas-Fajardo, Cristián
    Atacama Biotech, Santiago, Chile.
    Fonseca, Ricardo
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology. Instituto Andaluz de Ciencias de la Tierra (UGR-CSIC), Armilla, Granada, Spain.
    Fernández-Sampedro, Maite
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Fairén, Alberto G.
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain. Department of Astronomy, Cornell University, Ithaca, NY, USA.
    Zorzano Mier, María-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Aeolian transport of viable microbial life across the Atacama Desert, Chile: Implications for Mars2019In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, article id 11024Article in journal (Refereed)
    Abstract [en]

    Here we inspect whether microbial life may disperse using dust transported by wind in the Atacama Desert in northern Chile, a well-known Mars analog model. By setting a simple experiment across the hyperarid core of the Atacama we found that a number of viable bacteria and fungi are in fact able to traverse the driest and most UV irradiated desert on Earth unscathed using wind-transported dust, particularly in the later afternoon hours. This finding suggests that microbial life on Mars, extant or past, may have similarly benefited from aeolian transport to move across the planet and find suitable habitats to thrive and evolve.

  • 8.
    Baghel, Shreeya
    et al.
    Department of Soil and Water Engineering, CTAE MPUAT, Udaipur, India.
    Tripathi, M. P.
    Department of Soil and Water Engineering, SVCAET and RS, IGKV, Raipur, C.G., India.
    Khalkho, Dhiraj
    Soil and Water Engineering, Department of Soil and Water Engineering, SVCAET and RS, IGKV, Raipur, C.G., India.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Kumar, Aekesh
    Department of Soil and Water Conservation Engineering, College of Technology, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India.
    Elbeltagi, Ahmed
    Agricultural Engineering Department, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt.
    Delineation of suitable sites for groundwater recharge based on groundwater potential with RS, GIS, and AHP approach for Mand catchment of Mahanadi Basin2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 9860Article in journal (Refereed)
    Abstract [en]

    Groundwater management requires a systematic approach since it is crucial to the long-term viability of livelihoods and regional economies all over the world. There is insufficient groundwater management and difficulties in storage plans as a result of increased population, fast urbanisation, and climate change, as well as unpredictability in rainfall frequency and intensity. Groundwater exploration using remote sensing (RS) data and geographic information system (GIS) has become a breakthrough in groundwater research, assisting in the assessment, monitoring, and conservation of groundwater resources. The study region is the Mand catchment of the Mahanadi basin, covering 5332.07 km2 and is located between 21°42′15.525″N and 23°4′19.746″N latitude and 82°50′54.503″E and 83°36′1.295″E longitude in Chhattisgarh, India. The research comprises the generation of thematic maps, delineation of groundwater potential zones and the recommendation of structures for efficiently and successfully recharging groundwater utilising RS and GIS. Groundwater Potential Zones (GPZs) were identified with nine thematic layers using RS, GIS, and the Multi-Criteria Decision Analysis (MCDA) method. Satty's Analytic Hierarchy Process (AHP) was used to rank the nine parameters that were chosen. The generated GPZs map indicated regions with very low, low to medium, medium to high, and very high groundwater potential encompassing 962.44 km2, 2019.92 km2, 969.19 km2, and 1380.42 km2 of the study region, respectively. The GPZs map was found to be very accurate when compared with the groundwater fluctuation map, and it is used to manage groundwater resources in the Mand catchment. The runoff of the study area can be accommodated by the computing subsurface storage capacity, which will raise groundwater levels in the low and low to medium GPZs. According to the study results, various groundwater recharge structures such as farm ponds, check dams and percolation tanks were suggested in appropriate locations of the Mand catchment to boost groundwater conditions and meet the shortage of water resources in agriculture and domestic use. This study demonstrates that the integration of GIS can provide an efficient and effective platform for convergent analysis of various data sets for groundwater management and planning.

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  • 9.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University, P.O. Box 57561/51818, Urmia, Iran.
    Kazemi, Fatemeh
    Faculty of Engineering, University of Kashan, Kashan, Iran.
    Mirmohammadi, Mirsaleh
    School of Mining Engineering, University of Tehran, Tehran, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Farajzadeh, Saghar
    Department of Mining Engineering, Faculty of Engineering, Urmia University, P.O. Box 57561/51818, Urmia, Iran.
    Configuration of flowsheet and reagent dosage for gilsonite flotation towards the ultra-low-ash concentrate2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 15469Article in journal (Refereed)
    Abstract [en]

    Gilsonite has a wide variety of applications in the industry, including the manufacture of electrodes, paints and resins, as well as the production of asphalt and roof-waterproofing material. Gilsonite ash is a determining parameter for its application in some industries (e.g., gilsonite with ash content < 5% used as an additive in drilling fluids, resins). Due to the shortage of high grade (low ash) gilsonite reserves, the aim of this study is to develop a processing flowsheet for the production of ultra-low-ash gilsonite (< 5%), based on process mineralogy studies and processing tests. For this purpose, mineralogical studies and flotation tests have been performed on a sample of gilsonite with an average ash content of 15%. According to mineralogical studies, carbonates and clay minerals are the main associated impurities (more than 90 vol.%). Furthermore, sulfur was observed in two forms of mineral (pyrite and marcasite) and organic in the structure of gilsonite. Most of these impurities are interlocked with gilsonite in size fractions smaller than 105 µm. The size fraction of + 105 − 420 µm has a higher pure gilsonite (approximately 90%) than other size fractions. By specifying the gangue minerals with gilsonite and the manner and extent of their interlocking with gilsonite, + 75 − 420 µm size fraction selected to perform flotation tests. Flotation tests were performed using different reagents including collector (Gas oil, Kerosene and Pine oil), frother (MIBC) and depressant (sodium silicate, tannic acid, sulfuric acid and sodium cyanide) in different dosages. Based on the results, the use of kerosene collector, MIBC frother and a mixture of sodium silicate, tannic acid, sulfuric acid and sodium cyanide depressant had the most favorable results in gilsonite flotation in the rougher stage. Cleaner and recleaner flotation stages for the rougher flotation concentrate resulted in a product with an ash content of 4.89%. Due to the interlocking of gilsonite with impurities in size fractions − 105 µm, it is better to re-grinding the concentrate of the rougher stage beforehand flotation in the cleaner and recleaner stages. Finally, based on the results of mineralogical studies and processing tests, a processing flowsheet including crushing and initial granulation of gilsonite, flotation in rougher, cleaner and recleaner stages has been proposed to produce gilsonite concentrate with < 5% ash content.

  • 10.
    Barai, Manas
    et al.
    Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Manna, Emili
    Centre for Life Sciences, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Sultana, Habiba
    Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Mandal, Manas Kumar
    Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Guchhait, Kartik Chandra
    Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Manna, Tuhin
    Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Patra, Anuttam
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Chang, Chien-Hsiang
    Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.
    Moitra, Parikshit
    India and School of Applied & interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata, 700032, India.
    Ghosh, Chandradipa
    Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Bhattacharya, Santanu
    India and School of Applied & interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata, 700032, India; Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560012, Karnataka, India.
    Panda, Amiya Kumar
    Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.
    Micro-structural investigations on oppositely charged mixed surfactant gels with potential dermal applications2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 15527Article in journal (Refereed)
    Abstract [en]

    Dicarboxylic amino acid-based surfactants (N-dodecyl derivatives of -aminomalonate, -aspartate, and -glutamate) in combination with hexadecyltrimethylammonium bromide (HTAB) form a variety of aggregates. Composition and concentration-dependent mixtures exhibit liquid crystal, gel, precipitate, and clear isotropic phases. Liquid crystalline patterns, formed by surfactant mixtures, were identified by polarizing optical microscopy. FE-SEM studies reveal the existence of surface morphologies of different mixed aggregates. Phase transition and associated weight loss were found to depend on the composition where thermotropic behaviours were revealed through combined differential scanning calorimetry and thermogravimetric studies. Systems comprising more than 60 mol% HTAB demonstrate shear-thinning behaviour. Gels cause insignificant toxicity to human peripheral lymphocytes and irritation to bare mouse skin; they do not display the symptoms of cutaneous irritation, neutrophilic invasion, and inflammation (erythema, edema, and skin thinning) as evidenced by cumulative irritancy index score. Gels also exhibit substantial antibacterial effects on Staphylococcus aureus, a potent causative agent of skin and soft tissue infections, suggesting its possible application as a vehicle for topical dermatological drug delivery.

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  • 11.
    Basu, Kaustubh
    et al.
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Benetti, Daniele
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Zhao, Haiguang
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Jin, Lei
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Vetrone, Fiorenzo
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rosei, Frederico
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes2016In: Scientific Reports, E-ISSN 2045-2322, Vol. 6, article id 23312Article in journal (Refereed)
    Abstract [en]

    We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency

  • 12.
    Basu, Tirthankar
    et al.
    Department of Geography, University of Gour Banga, Malda, West Bengal, 732103, India.
    Das, Arijit
    Department of Geography, University of Gour Banga, Malda, West Bengal, 732103, India.
    Pham, Quoc Bao
    Environmental Quality, Atmospheric Science and Climate Change Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam. Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Linh, Nguyen Thi Thuy
    Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Vietnam.
    Lagerwall, Gareth
    Bioresources Engineering, School of Engineering, University of KwaZulu-Natal, Scottsville, P. Bag X01, Pietermaritzburg, 3209, Republic of South Africa. The Centre for Water Resources Research, University of KwaZulu-Natal, Scottsville, P. Bag X01, Pietermaritzburg, 3209, Republic of South Africa.
    Development of an integrated peri-urban wetland degradation assessment approach for the Chatra Wetland in eastern India2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 4470Article in journal (Refereed)
    Abstract [en]

    The loss of peri-urban wetlands is a major side effect of urbanization in India in recent days. Timely and proper assessment of wetland area change is essential for the conservation of wetlands. This study follows the integrated way of the peri-urban wetland degradation assessment in the case of medium and small-size urban agglomerations with a special focus on Chatra Wetland. Analysis of land-use and land cover (LULC) maps of the past 28 years shows a decrease of 60% area of the wetland including marshy land. This has reduced the ecosystem services value by about 71.90% over the period 1991–2018. From this end, The Land Change Modeler of IDRISI TerrSet using the combination of MLPNN and Markov Chain has been used to predict the LULC map of this region. The scenario-based modeling following the LULC conversion and nine explanatory variables suggests the complete loss of this wetland by 2045. However, the authors have also tried to present a future LULC pattern of this region based on an environmental perspective. This proposed map suggests possible areas for built-up expansion on the western side of the city without significantly affecting the environment.

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  • 13.
    Bhardwaj, Anshuman
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Sam, Lydia
    Institut für Kartographie, Technische Universität Dresden.
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Zorzano Mier, Maria-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Fonseca, Ricardo
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Martian slope streaks as plausible indicators of transient water activity2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, no 1, article id 7074Article in journal (Refereed)
    Abstract [en]

    Slope streaks have been frequently observed in the equatorial, low thermal inertia and dusty regions of Mars. The reason behind their formation remains unclear with proposed hypotheses for both dry and wet mechanisms. Here, we report an up-to-date distribution and morphometric investigation of Martian slope streaks. We find: (i) a remarkable coexistence of the slope streak distribution with the regions on Mars with high abundances of water-equivalent hydrogen, chlorine, and iron; (ii) favourable thermodynamic conditions for transient deliquescence and brine development in the slope streak regions; (iii) a significant concurrence of slope streak distribution with the regions of enhanced atmospheric water vapour concentration, thus suggestive of a present-day regolith-atmosphere water cycle; and (iv) terrain preferences and flow patterns supporting a wet mechanism for slope streaks. These results suggest a strong local regolith-atmosphere water coupling in the slope streak regions that leads to the formation of these fluidised features. Our conclusions can have profound astrobiological, habitability, environmental, and planetary protection implications

  • 14.
    Bhardwaj, Anshuman
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Sam, Lydia
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Zorzano Mier, María-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Discovery of recurring slope lineae candidates in Mawrth Vallis, Mars2019In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, article id 2040Article in journal (Refereed)
    Abstract [en]

    utside of established RSL regions and further prompt the inclusion of a new geographical region within the RSL candidate group. Our inferences on the RSL candidates are based on several morphological and geophysical evidences and analogies: (i) the dimensions of the RSL candidates are consistent with confirmed mid-latitude RSL; (ii) albedo and thermal inertia values are comparable to those of other mid-latitude RSL sites; and (iii) features are found in a summer season image and on the steep and warmest slopes. These results denote the plausible presence of transient liquid brines close to the previously proposed landing ellipse of the ExoMars rover, rendering this site particularly relevant to the search of life. Further investigations of Mawrth Vallis carried out at higher spatial and temporal resolutions are needed to identify more of such features at local scales to maximize the scientific return from the future Mars rovers, to prevent probable biological contamination during rover operations, to evade damage to rover components as brines can be highly corrosive, and to quantify the ability of the regolith at mid-latitudes to capture atmospheric water which is relevant for in-situ-resource utilization.

  • 15.
    Bota, András
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab. Integrated Science Lab, Department of Physics, Umeå University, 90187, Umeå, Sweden.
    Holmberg, Martin
    Integrated Science Lab, Department of Physics, Umeå University, 90187, Umeå, Sweden.
    Gardner, Lauren
    Department of Civil and Systems Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
    Rosvall, Martin
    Integrated Science Lab, Department of Physics, Umeå University, 90187, Umeå, Sweden.
    Socioeconomic and environmental patterns behind H1N1 spreading in Sweden2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 22512Article in journal (Refereed)
    Abstract [en]

    Identifying the critical factors related to influenza spreading is crucial in predicting and mitigating epidemics. Specifically, uncovering the relationship between epidemic onset and various risk indicators such as socioeconomic, mobility and climate factors can reveal locations and travel patterns that play critical roles in furthering an outbreak. We study the 2009 A(H1N1) influenza outbreaks in Sweden’s municipalities between 2009 and 2015 and use the Generalized Inverse Infection Method (GIIM) to assess the most significant contributing risk factors. GIIM represents an epidemic spreading process on a network: nodes correspond to geographical objects, links indicate travel routes, and transmission probabilities assigned to the links guide the infection process. Our results reinforce existing observations that the influenza outbreaks considered in this study were driven by the country’s largest population centers, while meteorological factors also contributed significantly. Travel and other socioeconomic indicators have a negligible effect. We also demonstrate that by training our model on the 2009 outbreak, we can predict the epidemic onsets in the following five seasons with high accuracy.

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  • 16.
    Buasiri, Thanyarat
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Habermehl-Cwirzen, Karin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Krzeminski, Lukasz
    The Institute of Engineering Materials and Biomaterials, Silesian University of Technology, 44-100, Gliwice, Poland.
    Cwirzen, Andrzej
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Novel humidity sensors based on nanomodified Portland cement2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 8189Article in journal (Refereed)
    Abstract [en]

    Commonly used humidity sensors are based on metal oxides, polymers or carbon. Their sensing accuracy often deteriorates with time, especially when exposed to higher temperatures or very high humidity. An alternative solution based on the utilization of Portland cement-based mortars containing in-situ grown carbon nanofibers (CNFs) was evaluated in this study. The relationship between the electrical resistivity, CNF content and humidity were determined. The highest sensitivity was observed for samples containing 10 wt.% of the nanomodified cement which corresponded to 0.27 wt.% of CNFs. The highest calculated sensitivity was approximately 0.01024 per 1% change in relative humidity (RH). The measured electrical resistivity is a linear function of the RH in the humidity range between 11% and 97%. The percolation threshold value was estimated to be at around 7 wt.% of the nanomodified cement, corresponding to ~0.19 wt.% of CNFs.

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  • 17.
    Chabuk, Ali
    et al.
    Department of Environment Engineering, College of Engineering, University of Babylon, Babylon, 51001, Iraq.
    Jahad, Udai A.
    Department of Environment Engineering, College of Engineering, University of Babylon, Babylon, 51001, Iraq.
    Majdi, Ali
    Building and Construction Techniques Engineering, Al-Mustaqbal University College, Babylon, 51001, Iraq.
    Majdi, Hasan S. H.
    Head of Faculty, Al-Mustaqbal University College, Babylon, 51001, Iraq.
    Isam, Mubeen
    Research and Studies Unit, Al-Mustaqbal University College, Babylon, 51001, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Estimating of gases emission from waste sites to generate electrical energy as a case study at Al-Hillah City in Iraq2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 15193Article in journal (Refereed)
    Abstract [en]

    Methane (CH4) is a greenhouse gas resulting from human activities, especially landflls, and it hasmany potential environmental issues, such as its major role in global warming. On the other hand,methane can be converted to liquid fuel or electricity using chemical conversion or gas turbinegenerators. Therefore, reusing such gases could be of great environmental and economic beneft. Inthis context, this study aims to estimate the emissions of methane gas from the landflls in Al-HillahCity, Iraq, from 2023 to 2070 and the producible electric energy from this amount. The estimatingprocess was carried out using the Land GEM model and compared with traditional models. Theobtained results demonstrated that the total estimated landfll methane emissions for 48 years are875,217 tons, and the average annual methane emission is 18,234 tons based on a yearly wasteaccumulation rate of 1,046,413 tons and a total waste amount of 50,227,808 tons. The anticipatedloads of methane gas can be utilized to generate about 287,442 MW/year of electricity from 2023to 2070. In conclusion, the results obtained from this study could be evidence of the potentialenvironmental and economic benefts of harvesting and reusing methane gas from landflls.

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  • 18.
    Chandran, Mathan
    et al.
    Fuel Cell Energy System Lab, Department of Automobile Engineering, PSG College of Technology, Coimbatore, Tamilnadu, India.
    Palaniswamy, Karthikeyan
    Department of Automobile Engineering, PSG College of Technology, Coimbatore, Tamilnadu, India.
    Karthik Babu, N. B.
    Department of Mechanical Engineering, Assam Energy Institute, Centre of Rajiv Gandhi Institute of Petroleum Technology, Sivasagar, Assam, 785697, India.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    A study of the influence of current ramp rate on the performance of polymer electrolyte membrane fuel cell2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, no 1, article id 21888Article in journal (Refereed)
    Abstract [en]

    Durability and reliability are the key factors that prevent fuel cells from successful implementation in automotive sector. Dynamic load change is a common and frequent condition that the fuel cell has to undergo in automotive applications. Fuel cells are more sensitive to changes in load conditions and degrade based on load variation representing idling, rated power, and high power operating conditions. To examine the influence of dynamic load step on the fuel cell performance, two similar cells of active 25 cm2 was tested under two different load step for the same dynamic load cycle. The main difference in dynamic load cycle 2 was the ramp rate which was fixed as 0.1, 0.3, and 0.25 A/cm2/s for 0.2, 0.6, and 1.0 A/cm2 respectively. To investigate the degradative effects, polarization curves, electrochemical impedance spectroscopy, and field emission scanning electron microscopy were used. The results indicated that the degradation rate increased in both dynamic load cycles but however the impact of load change was comparatively minimal in dynamic load cycle 2. The total degradation in performance was 20.67% and 10.72% in dynamic load cycles 1 and 2 respectively. Fuel cell performance degraded in a manner that was consistent with the electrochemical impedance spectroscopy and cross-sectional analysis of field emission scanning electron microscopy. The results prove that the degradation rate is dependent on the load step and the number of load cycles. Severe catalyst degradation and delamination were observed in fuel cells operated under dynamic load cycle 1.

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  • 19.
    Chipakwe, Vitalis
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Karlkvist, Tommy
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Chelgani, Saeed Chehreh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, no 1, article id 6502Article in journal (Refereed)
    Abstract [en]

    Grinding is the most energy-intensive step in mineral beneficiation processes. The use of grinding aids (GAs) could be an innovative solution to reduce the high energy consumption associated with size reduction. Surprisingly, little is known about the effects of GAs on downstream mineral beneficiation processes, such as flotation separation. The use of ecofriendly GAs such as polysaccharide-based materials would help multiply the reduction of environmental issues in mineral processing plants. As a practical approach, this work explored the effects of a novel polysaccharide-based grinding aid (PGA) on magnetite's grinding and its reverse flotation. Batch grinding tests indicated that PGA improved grinding performance by reducing energy consumption, narrowing particle size distribution of products, and increasing their surface area compared to grinding without PGA. Flotation tests on pure samples illustrated that PGA has beneficial effects on magnetite depression (with negligible effect on quartz floatability) through reverse flotation separation. Flotation of the artificial mixture ground sample in the presence of PGA confirmed the benefits, giving a maximum Fe recovery and grade of 84.4 and 62.5%, respectively. In the absence of starch (depressant), PGA resulted in a separation efficiency of 56.1% compared to 43.7% without PGA. The PGA adsorption mechanism was mainly via physical interaction based on UV–vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR), and stability analyses. In general, the feasibility of using PGA, a natural green polymer, was beneficial for both grinding and reverse flotation separation performance.

  • 20.
    Delgado-Bonal, A.
    et al.
    Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR).
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Human vision is determined based on information theory2016In: Scientific Reports, E-ISSN 2045-2322, Vol. 6, article id 36038Article in journal (Refereed)
    Abstract [en]

    It is commonly accepted that the evolution of the human eye has been driven by the maximum intensity of the radiation emitted by the Sun. However, the interpretation of the surrounding environment is constrained not only by the amount of energy received but also by the information content of the radiation. Information is related to entropy rather than energy. The human brain follows Bayesian statistical inference for the interpretation of visual space. The maximization of information occurs in the process of maximizing the entropy. Here, we show that the photopic and scotopic vision absorption peaks in humans are determined not only by the intensity but also by the entropy of radiation. We suggest that through the course of evolution, the human eye has not adapted only to the maximum intensity or to the maximum information but to the optimal wavelength for obtaining information. On Earth, the optimal wavelengths for photopic and scotopic vision are 555 nm and 508 nm, respectively, as inferred experimentally. These optimal wavelengths are determined by the temperature of the star (in this case, the Sun) and by the atmospheric composition.

  • 21.
    El Jery, Atef
    et al.
    Department of Chemical Engineering, College of Engineering, King Khalid University, 61411, Abha, Saudi Arabia.
    Alawamleh, Heba Saed Kariem
    Department of Basic Scientific Sciences, Al-Huson College, Al-Balqa Applied University, P. O. Box 50, Al-Huson, 21510, Jordan.
    Sami, Mustafa Humam
    Department of Pharmacy, Al-Noor University College, Nineveh, Iraq.
    Abbas, Hussein Abdullah
    College of Nursing, National University of Science and Technology, Dhi Qar, Iraq.
    Sammen, Saad Sh.
    Department of Civil Engineering, College of Engineering, University of Diyala, Baquba, Diyala Governorate, 32001, Iraq.
    Ahsan, Amimul
    Department of Civil and Environmental Engineering, Islamic University of Technology (IUT), Gazipur, 1704, Bangladesh; Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Imteaz, M. A.
    Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Shanableh, Abdallah
    Research Institute of Sciences and Engineering, University of Sharjah, 27272, Sharjah, United Arab Emirates; Department of Civil and Environmental Engineering, University of Sharjah, 27272, Sharjah, United Arab Emirates.
    Shafiquzzaman, Md.
    Department of Civil Engineering, College of Engineering, Qassim University, 51452, Buraidah, Saudi Arabia.
    Osman, Haitham
    Department of Chemical Engineering, College of Engineering, King Khalid University, 61411, Abha, Saudi Arabia.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Isotherms, kinetics and thermodynamic mechanism of methylene blue dye adsorption on synthesized activated carbon2024In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 970Article in journal (Refereed)
    Abstract [en]

    The treatment of methylene blue (MB) dye wastewater through the adsorption process has been a subject of extensive research. However, a comprehensive understanding of the thermodynamic aspects of dye solution adsorption is lacking. Previous studies have primarily focused on enhancing the adsorption capacity of methylene blue dye. This study aimed to develop an environmentally friendly and cost-effective method for treating methylene blue dye wastewater and to gain insights into the thermodynamics and kinetics of the adsorption process for optimization. An adsorbent with selective methylene blue dye adsorption capabilities was synthesized using rice straw as the precursor. Experimental studies were conducted to investigate the adsorption isotherms and models under various process conditions, aiming to bridge gaps in previous research and enhance the understanding of adsorption mechanisms. Several adsorption isotherm models, including Langmuir, Temkin, Freundlich, and Langmuir–Freundlich, were applied to theoretically describe the adsorption mechanism. Equilibrium thermodynamic results demonstrated that the calculated equilibrium adsorption capacity (qe) aligned well with the experimentally obtained data. These findings of the study provide valuable insights into the thermodynamics and kinetics of methylene blue dye adsorption, with potential applications beyond this specific dye type. The utilization of rice straw as an adsorbent material presents a novel and cost-effective approach for MB dye removal from wastewater.

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  • 22.
    Epafini, Mauro
    et al.
    Istituto per la Microelettronica e i Microsistemi, IMM-CNR.
    Kaciulis, Saulius
    Istituto per lo Studio dei Materiali Nanostrutturati, ISMN-CNR.
    Mezzi, Alessio
    Istituto per lo Studio dei Materiali Nanostrutturati, ISMN-CNR.
    Altamura, Davide
    Istituto di Cristallografia, IC-CNR.
    Giannini, Cinzia
    Istituto di Cristallografia, IC-CNR.
    Díaz, Raül
    Electrochemical Processes Unit, IMDEA Energy Institute, Avda.
    Force, Carmen
    NMR Unit, Centro de Apoyo Tecnológico, Universidad Rey Juan Carlos.
    Genç, Aziz
    Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra.
    Arbiol, Jordi
    Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra.
    Pietro, Siciliano
    Istituto per la Microelettronica e i Microsistemi, IMM-CNR.
    Comini, Elisabetta
    Department of Information Engineering, Brescia University.
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Inorganic Photocatalytic Enhancement: Activated RhB Photodegradation by Surface Modification of SnO2 Nanocrystals with V2O5-like species2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, article id 44763Article in journal (Refereed)
    Abstract [en]

    SnO2 nanocrystals were prepared by precipitation in dodecylamine at 100 °C, then they were reacted with vanadium chloromethoxide in oleic acid at 250 °C. The resulting materials were heat-treated at various temperatures up to 650 °C for thermal stabilization, chemical purification and for studying the overall structural transformations. From the crossed use of various characterization techniques, it emerged that the as-prepared materials were constituted by cassiterite SnO2 nanocrystals with a surface modified by isolated V(IV) oxide species. After heat-treatment at 400 °C, the SnO2 nanocrystals were wrapped by layers composed of vanadium oxide (IV-V mixed oxidation state) and carbon residuals. After heating at 500 °C, only SnO2 cassiterite nanocrystals were obtained, with a mean size of 2.8 nm and wrapped by only V2O5-like species. The samples heat-treated at 500 °C were tested as RhB photodegradation catalysts. At 10-7 M concentration, all RhB was degraded within 1 h of reaction, at a much faster rate than all pure SnO2 materials reported until now.

  • 23.
    Fatahi, Rasoul
    et al.
    School of Mining Engineering, College of Engineering, University of Tehran, Tehran, 16846-13114, Iran.
    Nasiri, Hamid
    Department of Computer Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
    Dadfar, Ehsan
    Production Department of Ilam Cement Plant, Ilam, Iran.
    Chelgani, Saeed Chehreh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Modeling of energy consumption factors for an industrial cement vertical roller mill by SHAP-XGBoost: a "conscious lab" approach2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, no 1, article id 7543Article in journal (Refereed)
    Abstract [en]

    Cement production is one of the most energy-intensive manufacturing industries, and the milling circuit of cement plants consumes around 4% of a year's global electrical energy production. It is well understood that modeling and digitalizing industrial-scale processes would help control production circuits better, improve efficiency, enhance personal training systems, and decrease plants' energy consumption. This tactical approach could be integrated using conscious lab (CL) as an innovative concept in the internet age. Surprisingly, no CL has been reported for the milling circuit of a cement plant. A robust CL interconnect datasets originated from monitoring operational variables in the plants and translating them to human basis information using explainable artificial intelligence (EAI) models. By initiating a CL for an industrial cement vertical roller mill (VRM), this study conducted a novel strategy to explore relationships between VRM monitored operational variables and their representative energy consumption factors (output temperature and motor power). Using SHapley Additive exPlanations (SHAP) as one of the most recent EAI models accurately helped fill the lack of information about correlations within VRM variables. SHAP analyses highlighted that working pressure and input gas rate with positive relationships are the key factors influencing energy consumption. eXtreme Gradient Boosting (XGBoost) as a powerful predictive tool could accurately model energy representative factors by R-square ever 0.80 in the testing phase. Comparison assessments indicated that SHAP-XGBoost could provide higher accuracy for VRM-CL structure than conventional modeling tools (Pearson correlation, Random Forest, and Support vector regression.

  • 24.
    Gonçalves, Gil
    et al.
    TEMA-NRD, Mechanical Engineering Department, University of Aveiro, University of Aveiro, Nanotechnology Research Division, University of Aveiro.
    Vila, Mercedes
    TEMA-NRD, Mechanical Engineering Department, University of Aveiro.
    Bdikin, Igor
    TEMA-NRD, Mechanical Engineering Department, University of Aveiro.
    de Andres, Alicia
    Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones.
    Emami, Nazanin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Ferreira, Rute A.S.
    Physics Department and CICECO, University of Aveiro.
    Carlos, Luis D.
    Physics Department and CICECO, University of Aveiro.
    Gracio, Jose
    TEMA-NRD, Mechanical Engineering Department, University of Aveiro.
    Marques, Paula A.P.A.
    TEMA-NRD, Mechanical Engineering Department, University of Aveiro.
    Breakdown into nanoscale of graphene oxide: Confined hot spot atomic reduction and fragmentation2014In: Scientific Reports, E-ISSN 2045-2322, Vol. 4, article id 6735Article in journal (Refereed)
    Abstract [en]

    Nano-graphene oxide (nano-GO) is a new class of carbon based materials being proposed for biomedical applications due to its small size, intrinsic optical properties, large specific surface area, and easy to functionalize. To fully exploit nano-GO properties, a reproducible method for its production is of utmost importance. Herein we report, the study of the sequential fracture of GO sheets onto nano-GO with controllable lateral width, by a simple, and reproducible method based on a mechanism that we describe as a confined hot spot atomic fragmentation/reduction of GO promoted by ultrasonication. The chemical and structural changes on GO structure during the breakage were monitored by XPS, FTIR, Raman and HRTEM. We found that GO sheets starts breaking from the defects region and in a second phase through the disruption of carbon bonds while still maintaining crystalline carbon domains. The breaking of GO is accompanied by its own reduction, essentially by the elimination of carboxylic and carbonyl functional groups. Photoluminescence and photothermal studies using this nano-GO are also presented highlighting the potential of this nanomaterial as a unique imaging/therapy platform

  • 25.
    Gorai, Priya Kumari
    et al.
    Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India.
    Bharti, Prahalad Singh
    Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
    Kumar, Shashi
    Department of Metabolic Engineering, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
    Rajacharya, Girish H.
    Department of Metabolic Engineering, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
    Bandyopadhyay, Sabyasachi
    Centralized Core Research Facility, All India Institute of Medical Sciences, New Delhi, India.
    Pal, Sujoy
    Department of GI Surgery, All India Institute of Medical Sciences, New Delhi, India.
    Dhingra, Renu
    Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India.
    Kumar, Rakesh
    Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
    Nikolajeff, Fredrik
    Luleå University of Technology, Department of Health, Learning and Technology, Nursing and Medical Technology.
    Kumar, Saroj
    Luleå University of Technology, Department of Health, Learning and Technology, Nursing and Medical Technology. Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
    Rani, Neerja
    Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India.
    C1QA and COMP: plasma-based biomarkers for early diagnosis of pancreatic neuroendocrine tumors2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 21021Article in journal (Refereed)
    Abstract [en]

    Pancreatic Neuroendocrine tumors (PanNET) are challenging to diagnose and often detected at advanced stages due to a lack of specific and sensitive biomarkers. This study utilized proteomics as a valuable approach for cancer biomarker discovery; therefore, mass spectrometry-based proteomic profiling was conducted on plasma samples from 12 subjects (3 controls; 5 Grade I, 4 Grade II PanNET patients) to identify potential proteins capable of effectively distinguishing PanNET from healthy controls. Data are available via ProteomeXchange with the identifier PXD045045. 13.2% of proteins were uniquely identified in PanNET, while 60% were commonly expressed in PanNET and controls. 17 proteins exhibiting significant differential expression between PanNET and controls were identified with downstream analysis. Further, 5 proteins (C1QA, COMP, HSP90B1, ITGA2B, and FN1) were selected by pathway analysis and were validated using Western blot analysis. Significant downregulation of C1QA (p = 0.001: within groups, 0.03: control vs. grade I, 0.0013: grade I vs. grade II) and COMP (p = 0.011: within groups, 0.019: control vs grade I) were observed in PanNET Grade I & II than in controls. Subsequently, ELISA on 38 samples revealed significant downregulation of C1QA and COMP with increasing disease severity. This study shows the potential of C1QA and COMP in the early detection of PanNET, highlighting their role in the search for early-stage (Grade-I and Grade-II) diagnostic markers and therapeutic targets for PanNET.

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  • 26.
    Gouvêa Junior, José Tadeu
    et al.
    Department of Mining and Petroleum Engineering, Polytechnic School, University of São Paulo, Avenida Professor Melo Moraes, 2373, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
    Chipakwe, Vitalis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    de Salles Leal Filho, Laurindo
    Department of Mining and Petroleum Engineering, Polytechnic School, University of São Paulo, Avenida Professor Melo Moraes, 2373, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
    Chelgani, Saeed Chehreh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Biodegradable ether amines for reverse cationic flotation separation of ultrafine quartz from magnetite2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 20550Article in journal (Refereed)
    Abstract [en]

    A considerable amount of ultrafine magnetite as the iron source will end up in the tailing dams since the magnetic separation process markedly drops as the particle size. Cationic reverse flotation could be one of the main alternatives for recovering ultrafine magnetite. As a systematic approach, this study explored the flotation efficiency and interaction mechanisms of two biodegradable ether amines (diamine and monoamine) to separate ultrafine quartz from magnetite (− 20 µm). Several assessments (single and mixed mineral flotation, zeta potential, contact angle, surface tension measurement, turbidity, and Fourier transform infrared) were conducted to explore the efficiency of the process and the interaction mechanisms. Results indicated that ether diamine and monoamine could highly float ultrafine quartz particles (95.9 and 97.7%, respectively) and efficiently separate them from ultrafine magnetite particles. Turbidity assessments highlighted that these cationic collectors could aggregate magnetite particles (potentially hydrophobic coagulation) and enhance their depression. Surface analyses revealed that the collector mainly adsorbed on the quartz particles, while it was essentially a weak interaction on magnetite.

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  • 27.
    Griesiute, Diana
    et al.
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Garskaite, Edita
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Antuzevics, Andris
    Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga, 1063, Latvia.
    Klimavicius, Vytautas
    Institute of Chemical Physics, Vilnius University, Sauletekio 3, 10257, Vilnius, Lithuania.
    Balevicius, Vytautas
    Institute of Chemical Physics, Vilnius University, Sauletekio 3, 10257, Vilnius, Lithuania.
    Zarkov, Aleksej
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Katelnikovas, Arturas
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Sandberg, Dick
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Kareiva, Aivaras
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Synthesis, structural and luminescent properties of Mn-doped calcium pyrophosphate (Ca2P2O7) polymorphs2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, no 1, article id 7116Article in journal (Refereed)
    Abstract [en]

    In the present work, three different Mn2+-doped calcium pyrophosphate (CPP, Ca2P2O7) polymorphs were synthesized by wet co-precipitation method followed by annealing at different temperatures. The crystal structure and purity were studied by powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR), solid-state nuclear magnetic resonance (SS-NMR), and electron paramagnetic resonance (EPR) spectroscopies. Scanning electron microscopy (SEM) was used to investigate the morphological features of the synthesized products. Optical properties were investigated using photoluminescence measurements. Excitation spectra, emission spectra, and photoluminescence decay curves of the samples were studied. All Mn-doped polymorphs exhibited a broadband emission ranging from approximately 500 to 730 nm. The emission maximum was host-dependent and centered at around 580, 570, and 595 nm for γ-, β-, and α-CPP, respectively.

  • 28.
    Gupta, Rajeev Kumar
    et al.
    Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, 141004, India.
    Sraw, Paramjit Kaur
    Department of Agronomy, Punjab Agricultural University, Ludhiana, 141004, India.
    Kang, Jasjit Singh
    Department of Agronomy, Punjab Agricultural University, Ludhiana, 141004, India.
    Kaur, Jagroop
    Department of Agronomy, Punjab Agricultural University, Ludhiana, 141004, India.
    Sharma, Vivek
    Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, 141004, India.
    Pathania, Neemisha
    Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, 141004, India.
    Kalia, Anu
    Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, 141004, India.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Alataway, Abed
    Prince Sultan Bin Abdulaziz International Prize for Water Chair, Prince Sultan Institute for Environmental, Water and Desert Research, King Saud University, 11451, Riyadh, Saudi Arabia.
    Dewidar, Ahmed Z.
    Prince Sultan Bin Abdulaziz International Prize for Water Chair, Prince Sultan Institute for Environmental, Water and Desert Research, King Saud University, 11451, Riyadh, Saudi Arabia; Department of Agricultural Engineering, College of Food and Agriculture Sciences, King Saud University, 11451, Riyadh, Saudi Arabia.
    Mattar, Mohamed A.
    Prince Sultan Bin Abdulaziz International Prize for Water Chair, Prince Sultan Institute for Environmental, Water and Desert Research, King Saud University, 11451, Riyadh, Saudi Arabia; Department of Agricultural Engineering, College of Food and Agriculture Sciences, King Saud University, 11451, Riyadh, Saudi Arabia; Agricultural Research Centre, Agricultural Engineering Research Institute (AEnRI), Giza, 12618, Egypt.
    Interactive effects of long-term management of crop residue and phosphorus fertilization on wheat productivity and soil health in the rice–wheat2024In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 1399Article in journal (Refereed)
    Abstract [en]

    In the context of degradation of soil health, environmental pollution, and yield stagnation in the rice–wheat system in the Indo-Gangetic Plains of South Asia, an experiment was established in split plot design to assess the long-term effect of crop residue management on productivity and phosphorus requirement of wheat in rice–wheat system. The experiment comprised of six crop residue management practices as the main treatment factor with three levels (0, 30 and 60 kg P2O5 ha–1) of phosphorus fertilizer as sub-treatments. Significant improvement in soil aggregation, bulk density, and infiltration rate was observed under residue management (retention/incorporation) treatments compared to residue removal or residue burning. Soil organic carbon (SOC), available nutrient content (N, P, and K), microbial count, and enzyme activities were also significantly higher in conservation tillage and residue-treated plots than without residue/burning treatments. The residue derived from both crops when was either retained/incorporated improved the soil organic carbon (0.80%) and resulted in a significant increase in SOC (73.9%) in the topsoil layer as compared to the conventional practice. The mean effect studies revealed that crop residue management practices and phosphorus levels significantly influenced wheat yield attributes and productivity. The higher grain yield of wheat was recorded in two treatments, i.e. the basal application of 60 kg P2O5 ha–1 without residue incorporation and the other with half the P-fertilizer (30 kg P2O5 ha–1) with rice residue only. The grain yield of wheat where the rice and wheat residue were either retained/incorporated without phosphorus application was at par with 30 and 60 kg P2O5ha–1. Phosphorus levels also significantly affected wheat productivity and available P content in the soil. Therefore, results suggested that crop residue retention following the conservation tillage approach improved the yield of wheat cultivated in the rice–wheat cropping system.

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  • 29.
    Halder, Bijay
    et al.
    Department of Remote Sensing and GIS, Vidyasagar University, Midnapore, 721102, India; New Era and Development in Civil Engineering Research Group, Scientific Research Center, Al-Ayen University, Nasiriyah, Thi-Qar, 64001, Iraq.
    Ahmadianfar, Iman
    Department of Civil Engineering, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.
    Heddam, Salim
    Agronomy Department, Faculty of Science, University, 20 Août 1955 Skikda, Route El Hadaik, BP 26, Skikda, Algeria.
    Mussa, Zainab Haider
    College of Pharmacy, University of Al-Ameed, Karbala, Iraq.
    Goliatt, Leonardo
    Computational Modeling Program, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil.
    Tan, Mou Leong
    GeoInformatic Unit, Geography Section, School of Humanities, Universiti Sains Malaysia, 11800, Penang, Malaysia; School of Geographical Sciences, Nanjing Normal University, Nanjing, 210023, China.
    Sa’adi, Zulfaqar
    Centre for Environmental Sustainability and Water Security, Research Institute for Sustainable Environment, Universiti Teknologi Malaysia (UTM), 81310, Sekudai, Johor, Malaysia.
    Al-Khafaji, Zainab
    Department of Building and Construction Technologies Engineering, AL-Mustaqbal University College, Hillah, 51001, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Jawad, Ali H.
    Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor, Malaysia.
    Yaseen, Zaher Mundher
    Civil and Environmental Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia; Interdisciplinary Research Center for Membranes and Water Security, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia.
    Machine learning-based country-level annual air pollutants exploration using Sentinel-5P and Google Earth Engine2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 7968Article in journal (Refereed)
    Abstract [en]

    Climatic condition is triggering human health emergencies and earth’s surface changes. Anthropogenic activities, such as built-up expansion, transportation development, industrial works, and some extreme phases, are the main reason for climate change and global warming. Air pollutants are increased gradually due to anthropogenic activities and triggering the earth’s health. Nitrogen Dioxide (NO2), Carbon Monoxide (CO), and Aerosol Optical Depth (AOD) are truthfully important for air quality measurement because those air pollutants are more harmful to the environment and human’s health. Earth observational Sentinel-5P is applied for monitoring the air pollutant and chemical conditions in the atmosphere from 2018 to 2021. The cloud computing-based Google Earth Engine (GEE) platform is applied for monitoring those air pollutants and chemical components in the atmosphere. The NO2 variation indicates high during the time because of the anthropogenic activities. Carbon Monoxide (CO) is also located high between two 1-month different maps. The 2020 and 2021 results indicate AQI change is high where 2018 and 2019 indicates low AQI throughout the year. The Kolkata have seven AQI monitoring station where high nitrogen dioxide recorded 102 (2018), 48 (2019), 26 (2020) and 98 (2021), where Delhi AQI stations recorded 99 (2018), 49 (2019), 37 (2020), and 107 (2021). Delhi, Kolkata, Mumbai, Pune, and Chennai recorded huge fluctuations of air pollutants during the study periods, where ~ 50–60% NO2 was recorded as high in the recent time. The AOD was noticed high in Uttar Pradesh in 2020. These results indicate that air pollutant investigation is much necessary for future planning and management otherwise; our planet earth is mostly affected by the anthropogenic and climatic conditions where maybe life does not exist.

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  • 30.
    Han, Zhenyao
    et al.
    School of Chemistry and Chemical Engineering and College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China.
    Chen, Hao
    School of Chemistry and Chemical Engineering and College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China.
    He, Chunlin
    School of Chemistry and Chemical Engineering and College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China.
    Dodbiba, Gjergj
    Graduate School of Engineering, The University of Tokyo, Bunkyo, Tokyo, 113-8656, Japan.
    Otsuki, Akira
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Diagonal Las Torres 2640, 11 Peñalolén, 7941169, Santiago, Chile.
    Wei, Yuezhou
    School of Nuclear Science and Technology, University of South China, Hengyang, 421001, Hunan, China.
    Fujita, Toyohisa
    School of Chemistry and Chemical Engineering and College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China.
    Nanobubble size distribution measurement by interactive force apparatus under an electric field2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 3663Article in journal (Refereed)
    Abstract [en]

    Nanobubbles have been applied in many fields, such as environmental cleaning, material production, agriculture, and medicine. However, the measured nanobubble sizes differed among the measurement methods, such as dynamic light scattering, particle trajectory, and resonance mass methods. Additionally, the measurement methods were limited with respect to the bubble concentration, refractive index of liquid, and liquid color. Here, a novel interactive force measurement method for bulk nanobubble size measurement was developed by measuring the force between two electrodes filled with bulk nanobubble-containing liquid under an electric field when the electrode distance was changed in the nm scale with piezoelectric equipment. The nanobubble size was measured with a bubble gas diameter and also an effective water thin film layer covered with a gas bubble that was estimated to be approximately 10 nm based on the difference between the median diameter of the particle trajectory method and this method. This method could also be applied to the solid particle size distribution measurement in a solution.

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  • 31.
    Hansen, Jonny
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements. Transmission Development, Scania CV AB, Södertälje, Sweden.
    Björling, Marcus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lubricant film formation in rough surface non‑conformal conjunctions subjected to GPa pressures and high slide‑to‑roll ratios2020In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, no 1, article id 22250Article in journal (Refereed)
    Abstract [en]

    A ball-on-disc machine was employed in a highly idealised setting to study the interplay between oil film formation and surface irregularities in single-sided rough elasto-hydrodynamic lubricated (EHL) conjunctions. The tests were operated under GPa pressures and high slide-to-roll ratios in a situation where the separating gap was smaller than the combined surface roughness height. Under the initial state of solid contact interference and with the operating conditions held fixed, surfaces were found to gradually conform such that a fully separating oil film of nanometre thickness eventually developed—a thin film lubrication state known as micro-EHL. Additionally, with a previously developed approach for 3D surface re-location analysis, we were able to very precisely specify the pertained nature of surface transformations, even at the asperity scale, by comparing the post-test surfaces to those in the virgin state. The surface roughness Sq was reduced by up to 17% after running-in, while the speed required for full film EHL was reduced by a remarkable 90%. Hence, full film EHL is possible even in cases where the Λ-ratio falsely suggests boundary lubrication. This discrepancy was attributed to the way surfaces are deformed inside the contact, i.e., through the establishment of micro-EHL.

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  • 32.
    Hassan, Mohammad L.
    et al.
    Cellulose and Paper Department and Centre of Excellence for Advanced Sciences, National Research Centre, 33 El-Buhouth street, Dokki, 12622, Giza, Egypt.
    Fadel, Shaimaa M.
    Cellulose and Paper Department and Centre of Excellence for Advanced Sciences, National Research Centre, 33 El-Buhouth street, Dokki, 12622, Giza, Egypt.
    Abouzeid, Ragab E.
    Cellulose and Paper Department and Centre of Excellence for Advanced Sciences, National Research Centre, 33 El-Buhouth street, Dokki, 12622, Giza, Egypt.
    Elseoud, Wafaa S. Abou
    Cellulose and Paper Department and Centre of Excellence for Advanced Sciences, National Research Centre, 33 El-Buhouth street, Dokki, 12622, Giza, Egypt View author publications.
    Hassan, Enas A.
    Cellulose and Paper Department and Centre of Excellence for Advanced Sciences, National Research Centre, 33 El-Buhouth street, Dokki, 12622, Giza, Egypt.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON, M5S 3G8, Canada.
    Water purification ultrafiltration membranes using nanofibers from unbleached and bleached rice straw2020In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, article id 11278Article in journal (Refereed)
    Abstract [en]

    There has been an increasing interest in recent years in isolating cellulose nanofibers from unbleached cellulose pulps for economic, environmental, and functional reasons. In the current work, cellulose nanofibers isolated from high-lignin unbleached neutral sulfite pulp were compared to those isolated from bleached rice straw pulp in making thin-film ultrafiltration membranes by vacuum filtration on hardened filter paper. The prepared membranes were characterized in terms of their microscopic structure, hydrophilicity, pure water flux, protein fouling, and ability to remove lime nanoparticles and purify papermaking wastewater effluent. Using cellulose nanofibers isolated from unbleached pulp facilitated the formation of a thin-film membrane (with a shorter filtration time for thin-film formation) and resulted in higher water flux than that obtained using nanofibers isolated from bleached fibers, without sacrificing its ability to remove the different pollutants.

  • 33.
    Hedman, Daniel
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Barzegar, Hamid Reza
    Department of Physics, Umeå University, Department of Physics, University of California.
    Rosén, Arne
    Physics Department, Göteborg University.
    Wågberg, Thomas
    Department of Physics, Umeå University.
    Larsson, Andreas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    On the Stability and Abundance of Single Walled Carbon Nanotubes2015In: Scientific Reports, E-ISSN 2045-2322, Vol. 5, article id 16850Article in journal (Refereed)
    Abstract [en]

    Many nanotechnological applications, using single-walled carbon nanotubes (SWNTs), are only possible with a uniform product. Thus, direct control over the product during chemical vapor deposition (CVD) growth of SWNT is desirable, and much effort has been made towards the ultimate goal of chirality-controlled growth of SWNTs. We have used density functional theory (DFT) to compute the stability of SWNT fragments of all chiralities in the series representing the targeted products for such applications, which we compare to the chiralities of the actual CVD products from all properly analyzed experiments. From this comparison we find that in 84% of the cases the experimental product represents chiralities among the most stable SWNT fragments (within 0.2 eV) from the computations. Our analysis shows that the diameter of the SWNT product is governed by the well-known relation to size of the catalytic nanoparticles, and the specific chirality is normally determined by the product’s relative stability, suggesting thermodynamic control at the early stage of product formation. Based on our findings, we discuss the effect of other experimental parameters on the chirality of the product. Furthermore, we highlight the possibility to produce any tube chirality in the context of recent published work on seeded-controlled growth.

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  • 34.
    Hua, Jing
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Björling, Marcus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Shi, Yijun
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    A smart friction control strategy enabled by CO2 absorption and desorption2019In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, no 1, article id 13262Article in journal (Refereed)
    Abstract [en]

    Intelligent control of friction is an attractive but challenging topic and it has rarely been investigated for full size engineering applications. In this work, it is instigated if it would be possible to adjust friction by controlling viscosity in a lubricated contact. By exploiting the ability to adjust the viscosity of the switchable ionic liquids, 1,8-Diazabicyclo (5.4.0) undec-7-ene (DBU)/ glycerol mixture via the addition of CO2, the friction could be controlled in the elastohydrodynamic lubrication (EHL) regime. The friction decreased with increasing the amount of CO2 to the lubricant and increased after partial releasing CO2. As CO2 was absorbed by the liquid, the viscosity of the liquid increased which resulted in that the film thickness increased. At the same time the pressure-viscosity coefficient decreased with the addition of CO2. When CO2 was released again the friction increased and it was thus possible to control friction by adding or removing CO2.

  • 35.
    Hunt, Cameron J
    et al.
    Department of Chemical Engineering, Monash University, Clayton, 3800, Victoria, Australia..
    Antonopoulou, Io
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Tanksale, Akshat
    Department of Chemical Engineering, Monash University, Clayton, 3800, Victoria, Australia..
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Haritos, Victoria S
    Department of Chemical Engineering, Monash University, Clayton, 3800, Victoria, Australia.
    Insights into substrate binding of ferulic acid esterases by arabinose and methyl hydroxycinnamate esters and molecular docking2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, no 1, article id 17315Article in journal (Refereed)
    Abstract [en]

    Ferulic acid esterases (FAE, EC 3.1.1.73) cleave the arabinose hydroxycinnamate ester in plant hemicellulose and other related substrates. FAE are commonly categorised as type A-D based on catalytic activities towards model, short alkyl chain esters of hydroxycinnamates. However, this system correlates poorly with sequence and structural features of the enzymes. In this study, we investigated the basis of the type A categorisation of an FAE from Aspergillus niger, AnFaeA, by comparing its activity toward methyl and arabinose hydroxycinnamate esters. kcat/Km ratios revealed that AnFaeA hydrolysed arabinose ferulate 1600-fold, and arabinose caffeate 6.5 times more efficiently than their methyl ester counterparts. Furthermore, small docking studies showed that while all substrates adopted a catalytic orientation with requisite proximity to the catalytic serine, methyl caffeate and methyl p-coumarate preferentially formed alternative non-catalytic conformations that were energetically favoured. Arabinose ferulate was unable to adopt the alternative conformation while arabinose caffeate preferred the catalytic orientation. This study demonstrates that use of short alkyl chain hydroxycinnnamate esters can result in activity misclassification. The findings of this study provide a basis for developing a robust classification system for FAE and form the basis of sequence-function relationships for this class.

  • 36.
    Ilstedt, U.
    et al.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences—SLU.
    Tobella, A. Bargues
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences—SLU.
    Bazie, H.R.
    Institut de l'Environnement et de Recherches Agricoles, Departement Productions.
    Bayala, J.H.
    World Agroforestry Centre (ICRAF), West and Central Africa Regional Office, Sahel.
    Verbeeten, E.
    Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam.
    Nyberg, Gert
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Sanou, J.
    Institut de l'Environnement et de Recherches Agricoles, Departement Productions.
    Benegas, L.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences—SLU.
    Murdiyarso, D.
    Department of Geophysics and Meteorology, Bogor Agricultural University, Jl..
    Laudon, H.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences—SLU.
    Sheil, D.
    Center for International Forestry Research, Jl. CIFOR, Situgede, Bogor.
    Malmer, A.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences—SLU.
    Intermediate tree cover can maximize groundwater recharge in the seasonally dry tropics2016In: Scientific Reports, E-ISSN 2045-2322, Vol. 6, article id 21930Article in journal (Refereed)
    Abstract [en]

    Water scarcity contributes to the poverty of around one-third of the world's people. Despite many benefits, tree planting in dry regions is often discouraged by concerns that trees reduce water availability. Yet relevant studies from the tropics are scarce, and the impacts of intermediate tree cover remain unexplored. We developed and tested an optimum tree cover theory in which groundwater recharge is maximized at an intermediate tree density. Below this optimal tree density the benefits from any additional trees on water percolation exceed their extra water use, leading to increased groundwater recharge, while above the optimum the opposite occurs. Our results, based on groundwater budgets calibrated with measurements of drainage and transpiration in a cultivated woodland in West Africa, demonstrate that groundwater recharge was maximised at intermediate tree densities. In contrast to the prevailing view, we therefore find that moderate tree cover can increase groundwater recharge, and that tree planting and various tree management options can improve groundwater resources. We evaluate the necessary conditions for these results to hold and suggest that they are likely to be common in the seasonally dry tropics, offering potential for widespread tree establishment and increased benefits for hundreds of millions of people

  • 37.
    Jacobsson, Adam
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Johansson, Gustav
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Gorbatov, Oleg I.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ležaić, M.
    Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany.
    Sanyal, B.
    Department of Physics and Astronomy, Uppsala University, Box 516, 75120, Uppsala, Sweden.
    Blügel, S.
    Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany.
    Etz, Corina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Efficient parameterisation of non-collinear energy landscapes in itinerant magnets2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, article id 18987Article in journal (Refereed)
    Abstract [en]

    Magnetic exchange interactions determine the magnetic groundstate, as well as magnetic excitations of materials and are thus essential to the emerging and fast evolving fields of spintronics and magnonics. The magnetic force theorem has been used extensively for studying magnetic exchange interactions. However, short-ranged interactions in itinerant magnetic systems are poorly described by this method and numerous strategies have been developed over the years to overcome this deficiency. The present study supplies a fully self-consistent method for systematic investigations of exchange interactions beyond the standard Heisenberg model. In order to better describe finite deviations from the magnetic ground state, an extended Heisenberg model, including multi-spin interactions, is suggested. Using cross-validation analysis, we show that this extended Heisenberg model gives a superior description for non-collinear magnetic configurations. This parameterisation method allows us to describe many different itinerant magnetic systems and can be useful for high-throughput calculations.

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  • 38.
    Karoblis, Dovydas
    et al.
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Zarkov, Aleksej
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Garskaite, Edita
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Mazeika, Kestutis
    Center for Physical Sciences and Technology, 02300, Vilnius, Lithuania.
    Baltrunas, Dalis
    Center for Physical Sciences and Technology, 02300, Vilnius, Lithuania.
    Niaura, Gediminas
    Department of Organic Chemistry, Center for Physical Sciences and Technology, Sauletekio Ave. 3, 10257, Vilnius, Lithuania. Institute of Chemical Physics, Faculty of Physics, Vilnius University, Sauletekio Ave. 3, 10257, Vilnius, Lithuania.
    Beganskiene, Aldona
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Kareiva, Aivaras
    Institute of Chemistry, Vilnius University, Naugarduko 24, 03225, Vilnius, Lithuania.
    Study of gadolinium substitution effects in hexagonal yttrium manganite YMnO32021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 2875Article in journal (Refereed)
    Abstract [en]

    In the present work, gadolinium substitution effects on the properties of yttrium manganite YxGd1−xMn0.97Fe0.03O3 (x from 0 to 1 with a step of 0.2) synthesized by an aqueous sol–gel method have been investigated. Partial substitution of Mn3+ by 57Fe3+ in the manganite was also performed in order to investigate deeper the structural properties of synthesized compounds applying Mössbauer spectroscopy. It was demonstrated that substitution of Y3+ by Gd3+ ions leads to the changes of structural, magnetic and morphological properties of investigated system. The crystal structure gradually transformed from hexagonal to orthorhombic with an increase of Gd3+ content in the crystal lattice. The mixed phase was obtained when x = 0.6, whereas other compounds were determined to be monophasic. Magnetization measurements revealed paramagnetic behavior of all specimens, however magnetization values were found to be dependent on chemical composition of the samples. Solid solutions with orthorhombic structure revealed higher magnetization values compared to those of hexagonal samples. The highest magnetization was observed for pure GdMn0.97Fe0.03O3. Structural properties were investigated by powder X-ray diffraction, Mössbauer, FTIR and Raman spectroscopies. Morphological features of the synthesized specimens were studied by scanning electron microscopy (SEM).

  • 39.
    Khan, Md. Habibur Rahman Bejoy
    et al.
    Department of Civil and Environmental Engineering, Islamic University of Technology, Gazipur, Bangladesh.
    Ahsan, Amimul
    Department of Civil and Environmental Engineering, Islamic University of Technology, Gazipur, Bangladesh; Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Imteaz, M.
    Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Shafiquzzaman, Md.
    Department of Civil Engineering, College of Engineering, Qassim University, 51452 Buraidah, Saudi Arabia.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Evaluation of the surface water quality using global water quality index (WQI) models: perspective of river water pollution2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 20454Article in journal (Refereed)
    Abstract [en]

    Rapid industrialization, urbanization, global warming, and climate change are compromising surface water quality across the globe. Consequently, water conservation is essential for both environmental sustainability and human survival. This study assesses the water quality of the Jamuna River in Bangladesh at five distinct sites during wet and dry seasons. It employs six global water quality indices (WQIs) and contrasts the results with Bangladesh's Environmental Quality Standard (EQS) and the Department of Environment (DoE) criteria. The WQI models used are the Weighted Arithmetic WQI (WAWQI), British Columbia WQI (BCWQI), Canadian Council of Ministers of the Environment WQI (CWQI), Assigned WQI (AWQI), Malaysian WQI (MWQI), and Oregon WQI (OWQI). Fifteen physicochemical parameters were analyzed according to each WQI model's guidelines. The findings reveal that most parameters surpass the standard permissible values. The WQI model results indicate that the average water quality across the five sites falls into the lowest category. A comparison of the WQI models suggests potential correlations between WAWQI and AWQI, as well as between MWQI and OWQI. The straightforward presentation of the WQI models indicates that while the river water requires treatment for household and drinking use, it remains suitable for irrigation. The decline in water quality is likely attributable to human activities, urbanization, municipal waste disposal, and industrial effluents. Authorities must prioritize regular monitoring and assessment of water quality to address the identified challenges. Restoring the water to an acceptable standard will become increasingly difficult without proactive measures.

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  • 40.
    Kordloo, Mehrdad
    et al.
    School of Mining Engineering, College of Engineering, University of Tehran, Iran.
    Khodadadmahmoudi, Gholamreza
    School of Mining Engineering, College of Engineering, University of Tehran, Iran.
    Ebrahimi, Ehsan
    School of Mining Engineering, College of Engineering, University of Tehran, Iran.
    Rezaei, Ali
    School of Mining Engineering, College of Engineering, University of Tehran, Iran.
    Tohry, Arash
    Mining and Metallurgical Engineering Department, Yazd University, Iran.
    Chehreh Chelgani, Saeed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Green hematite depression for reverse selective flotation separation from quartz by locust bean gum2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 8980Article in journal (Refereed)
    Abstract [en]

    Reverse cationic flotation is currently the main processing technique for upgrading fine hematite from silicates. Flotation is known as an efficient method of mineral enrichment that deals with possibly hazardous chemicals. Thus, using eco-friendly flotation reagents for such a process is an emerging need for sustainable development and green transition. As an innovative approach, this investigation explored the potential of locust bean gum (LBG) as a biodegradable depressant for the selective separation of fine hematite from quartz through reverse cationic flotation. Various flotation conditions (micro and batch flotation) were conducted, and the mechanisms of LBG adsorption have been examined by different analyses (contact angle measurement, surface adsorption, zeta potential measurements, and FT-IR analysis). The micro flotation outcome indicated that the LBG could selectively depress hematite particles with negligible effect on quartz floatability. Flotation of mixed minerals (hematite and quartz mixture in various ratios) indicated that LGB could enhance separation efficiency (hematite recovery > 88%). Outcomes of the surface wettability indicated that even in the presence of the collector (dodecylamine), LBG decreased the hematite work of adhesion and had a slight effect on quartz. The LBG adsorbed selectively by hydrogen bonding on the surface of hematite based on various surface analyses.

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  • 41.
    Leal, José
    et al.
    Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany.
    Shaner, Sebastian
    Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany.
    Jedrusik, Nicole
    Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany.
    Savelyeva, Anna
    Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany.
    Asplund, Maria
    Luleå University of Technology, Department of Health, Learning and Technology, Nursing and Medical Technology. Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Center, University of Freiburg, Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany; Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden.
    Electrotaxis evokes directional separation of co-cultured keratinocytes and fibroblasts2023In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 11444Article in journal (Refereed)
    Abstract [en]

    Bioelectric communication plays a significant role in several cellular processes and biological mechanisms, such as division, differentiation, migration, cancer metastasis, and wound healing. Ion flow across cellular walls leads to potential gradients and subsequent formation of constant or time-varying electric fields(EFs), which regulate cellular processes. An EF is natively generated towards the wound center during epithelial wound healing, aiming to align and guide cell migration, particularly of macrophages, fibroblasts, and keratinocytes. While this phenomenon, known as electrotaxis or galvanotaxis, has been extensively investigated across many cell types, it is typically explored one cell type at a time, which does not accurately represent cellular interactions during complex biological processes. Here we show the co-cultured electrotaxis of epidermal keratinocytes and dermal fibroblasts with a salt-bridgeless microfluidic approach for the first time. The electrotactic response of these cells was first assessed in mono-culture to establish a baseline, resulting in the characteristic cathodic migration for keratinocytes and anodic for fibroblasts. Both cell types retained their electrotactic properties in co-culture leading to clear cellular partition even in the presence of cellular collisions. The methods leveraged here pave the way for future co-culture electrotaxis experiments where the concurrent influence of cell types can be thoroughly investigated.

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  • 42.
    Liu, Jian-li
    et al.
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Yao, Jun
    School of Water Resource and Environment Engineering, China University of Geosciences, Beijing.
    Wang, Fei
    School of Energy and Environment Engineering, University of Science and Technology Beijing, Beijing.
    Ni, Wen
    School of Civil and Resource Engineering, University of Science and Technology Beijing.
    Liu, Xing-yu
    National Engineering Laboratory of Biohydrometallurgy, General Research. Institute for Nonferrous Metals .
    Sunahara, Geoffrey
    Department of Natural Resource Sciences, McGill University, Montreal, Quebec.
    Duran, Robert
    Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l’Adour, IPREM UMR CNRS.
    Jordan, Gyozo
    Department of Applied Chemistry, Szent István University.
    Hudson-Edwards, Karen A.
    Environment & Sustainability Institute and Camborne School of Mines, University of Exeter.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Solevic-Knudsen, Tatjana
    Institute of Chemistry, Technology and Metallurgy, University of Belgrade.
    Zhu, Xiao-zhe
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Zhang, Yi-yue
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Li, Zi-fu
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    China's most typical nonferrous organic-metal facilities own specific microbial communities2018In: Scientific Reports, E-ISSN 2045-2322, Vol. 8, no 1, article id 12570Article in journal (Refereed)
    Abstract [en]

    The diversity and function of microorganisms have yet to be explored at non-ferrous metal mining facilities (NMMFs), which are the world's largest and potentially most toxic sources of co-existing metal(loid)s and flotation reagents (FRs). The diversity and inferred functions of different bacterial communities inhabiting two types of sites (active and abandoned) in Guangxi province (China) were investigated for the first time. Here we show that the structure and diversity of bacteria correlated with the types of mine sites, metal(loid)s, and FRs concentrations; and best correlated with the combination of pH, Cu, Pb, and Mn. Combined microbial coenobium may play a pivotal role in NMMFs microbial life. Arenimonas, specific in active mine sites and an acidophilic bacterium, carries functions able to cope with the extreme conditions, whereas Latescibacteria specific in abandoned sites can degrade organics. Such a bacterial consortium provides new insights to develop cost-effective remediation strategies of co-contaminated sites that currently remain intractable for bioremediation.

  • 43.
    Liu, Yang
    et al.
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou.
    Feng, Peizhong
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou.
    Wang, Zhang
    School of Material Science and Engineering, China University of Mining and Technology, Xuzhou.
    Jiao, Xinyang
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Novel Fabrication and Enhanced Photocatalytic MB Degradation of Hierarchical Porous Monoliths of MoO3 Nanoplates2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, no 1, article id 1845Article in journal (Refereed)
    Abstract [en]

    Porous monoliths of MoO3 nanoplates were synthesized from ammonium molybdate (AHM) by freeze-casting and subsequent thermal treatment from 300 to 600 °C. Pure orthorhombic MoO3 phase was obtained at thermal treatment temperature of 400 °C and above. MoO3 monoliths thermally treated at 400 °C displayed bimodal pore structure, including large pore channels replicating the ice crystals and small pores from MoO3 sheets stacking. Transmission electron microscopy (TEM) images revealed that the average thicknesses of MoO3 sheet were 50 and 300 nm in porous monoliths thermally treated at 400 °C. The photocatalytic performance of MoO3 was evaluated through degradation of methylene blue (MB) under visible light radiation and MoO3 synthesized at 400 °C exhibited strong adsorption performance and best photocatalytic activity for photodegradation of MB of 99.7% under visible illumination for 60 min. MoO3 photocatalyst displayed promising cyclic performance, and the decolorization efficiency of MB solution was 98.1% after four cycles

  • 44.
    López-Delgado, R.
    et al.
    MEMS Research Lab, Department of Physics and Astronomy, University of Texas at San Antonio.
    Zhou, Yufeng
    INRS Centre for Energy, Materials and Telecommunications, Varennes, QC.
    Zazueta-Raynaud, A.
    MEMS Research Lab, Department of Physics and Astronomy, University of Texas at San Antonio.
    Zhao, Haiguang
    INRS-EMT, Varennes, QC.
    Pelayo, J.E.
    MEMS Research Lab, Department of Physics and Astronomy, University of Texas at San Antonio.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Alvarez-Ramos, M.E.
    Departamento de Fisica, Universidad de Sonora, Hermosillo.
    Rosei, Frederico
    Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, Université du Québec, Varennes, Québec.
    Ayon, Arturo
    MEMS Research Lab, Department of Physics and Astronomy, University of Texas at San Antonio.
    Enhanced conversion efficiency in Si solar cells employing photoluminescent down-shifting CdSe/CdS core/shell quantum dots2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, no 1, article id 14104Article in journal (Refereed)
    Abstract [en]

    Silicon solar cells have captured a large portion of the total market of photovoltaic devices mostly due to their relatively high efficiency. However, Silicon exhibits limitations in ultraviolet absorption because high-energy photons are absorbed at the surface of the solar cell, in the heavily doped region, and the photo-generated electron-hole pairs need to diffuse into the junction region, resulting in significant carrier recombination. One of the alternatives to improve the absorption range involves the use of down-shifting nano-structures able to interact with the aforementioned high energy photons. Here, as a proof of concept, we use downshifting CdSe/CdS quantum dots to improve the performance of a silicon solar cell. The incorporation of these nanostructures triggered improvements in the short circuit current density (Jsc, from 32.5 to 37.0 mA/cm2). This improvement led to a ∼13% increase in the power conversion efficiency (PCE), from 12.0 to 13.5%. Our results demonstrate that the application of down-shifting materials is a viable strategy to improve the efficiency of Silicon solar cells with mass-compatible techniques that could serve to promote their widespread utilization.

  • 45.
    Mahmood, Zafar
    et al.
    Department of Mathematics and Statistics, Hazara University, Mansehra, Pakistan.
    Alhazmi, Sharifah E.
    Mathematics Department, Al-Qunfudah University College, Umm Al-Qura University, Mecca, Kingdom of Saudi Arabia.
    Alhowaity, Awatif
    Department of Mathematics, College of Science and Arts at Alkamil, University of Jeddah, Jeddah, Saudi Arabia.
    Marzouki, Riadh
    Chemistry Department, College of Science, King Khalid University, Abha, 61413, Saudi Arabia; Chemistry Department, Faculty of Sciences of Sfax, University of Sfax, 3038, Sfax, Tunisia.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Khan, Umar
    Department of Mathematics and Statistics, Hazara University, Mansehra, Pakistan.
    MHD mixed convective stagnation point flow of nanofluid past a permeable stretching sheet with nanoparticles aggregation and thermal stratification2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, article id 16020Article in journal (Refereed)
    Abstract [en]

    Using a thermally stratified water-based nanofluid and a permeable stretching sheet as a simulation environment, this research examines the impact of nanoparticle aggregation on MHD mixed convective stagnation point flow. Nanoparticle aggregation is studied using two modified models: the Krieger–Dougherty and the Maxwell–Bruggeman. The present problem's governing equations were transformed into a solvable mathematical model utilizing legitimate similarity transformations, and numerical solutions were then achieved using shooting with Runge–Kutta Fehlberg (RKF) technique in Mathematica. Equilibrium point flow toward permeable stretching surface is important for the extrusion process because it produces required heat and mass transfer patterns and identifies and clarifies fragmented flow phenomena using diagrams. Nanoparticle volume fraction was shown to have an impact on the solutions' existence range, as well. Alumina and copper nanofluids have better heat transfer properties than regular fluids. The skin friction coefficients and Nusselt number, velocity, temperature profiles for many values of the different parameters were obtained. In addition, the solutions were shown in graphs and tables, and they were explained in detail. A comparison of the current study's results with previous results for a specific instance is undertaken to verify the findings, and excellent agreement between them is observed.

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  • 46.
    Mateo-Marti, E.
    et al.
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Galvez-Martinez,, S.
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Gil-Lozano, C.
    Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Zorzano Mier, María-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology. Centro de Astrobiología (CSIC-INTA), Madrid, Spain.
    Pyrite-induced uv-photocatalytic abiotic nitrogen fixation: implications for early atmospheres and Life2019In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, no 1, article id 15311Article in journal (Refereed)
    Abstract [en]

    The molecular form of nitrogen, N2, is universally available but is biochemically inaccessible for life due to the strength of its triple bond. Prior to the emergence of life, there must have been an abiotic process that could fix nitrogen in a biochemically usable form. The UV photo-catalytic effects of minerals such as pyrite on nitrogen fixation have to date been overlooked. Here we show experimentally, using X-ray photoemission and infrared spectroscopies that, under a standard earth atmosphere containing nitrogen and water vapour at Earth or Martian pressures, nitrogen is fixed to pyrite as ammonium iron sulfate after merely two hours of exposure to 2,3 W/m 2 of ultraviolet irradiance in the 200–400 nm range. Our experiments show that this process exists also in the absence of UV, although about 50 times slower. The experiments also show that carbonates species are fixed on pyrite surface.

  • 47.
    McCloy, John S.
    et al.
    School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, USA; Materials Science and Engineering Program, Washington State University, Pullman, WA, USA; Department of Materials Science and Engineering, University of Shefeld, Shefeld, UK; Pacifc Northwest National Laboratory, Richland, WA, USA.
    Marcial, José
    School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, USA; Pacifc Northwest National Laboratory, Richland, WA, USA.
    Clarke, Jack S.
    Department of Materials Science and Engineering, University of Shefeld, Shefeld, UK.
    Ahmadzadeh, Mostafa
    School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, USA; Materials Science and Engineering Program, Washington State University, Pullman, WA, USA.
    Wolf, John A.
    School of the Environment, Washington State University, Pullman, WA, USA.
    Vicenzi, Edward P.
    Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA.
    Bollinger, David L.
    Materials Science and Engineering Program, Washington State University, Pullman, WA, USA.
    Ogenhall, Erik
    The Archaeologists, National Historical Museums (SHM), Uppsala, Sweden.
    Englund, Mia
    The Archaeologists, National Historical Museums (SHM), Uppsala, Sweden.
    Pearce, Carolyn I.
    Pacifc Northwest National Laboratory, Richland, WA, USA.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kruger, Albert A.
    US Department of Energy, Richland, WA, USA.
    Reproduction of melting behavior for vitrified hillforts based on amphibolite, granite, and basalt lithologies2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 1272Article in journal (Refereed)
    Abstract [en]

    European Bronze and Iron Age vitrified hillforts have been known since the 1700s, but archaeological interpretations regarding their function and use are still debated. We carried out a series of experiments to constrain conditions that led to the vitrification of the inner wall rocks in the hillfort at Broborg, Sweden. Potential source rocks were collected locally and heat treated in the laboratory, varying maximum temperature, cooling rate, and starting particle size. Crystalline and amorphous phases were quantified using X-ray diffraction both in situ, during heating and cooling, and ex situ, after heating and quenching. Textures, phases, and glass compositions obtained were compared with those for rock samples from the vitrified part of the wall, as well as with equilibrium crystallization calculations. ‘Dark glass’ and its associated minerals formed from amphibolite or dolerite rocks melted at 1000–1200 °C under reducing atmosphere then slow cooled. ‘Clear glass’ formed from non-equilibrium partial melting of feldspar in granitoid rocks. This study aids archaeological forensic investigation of vitrified hillforts and interpretation of source rock material by mapping mineralogical changes and glass production under various heating conditions.

  • 48.
    Milan, R.
    et al.
    Department of Information Engineering, University of Brescia, Via Branze 38, 9, Brescia, 25131, Italy;CNR-INO SENSOR Laboratory, via Branze 45, Brescia, 25123, Italy.
    Cattarin, S.
    ICMATE–CNR, Corso Stati Uniti 4, Padova, 35127, Italy.
    Comisso, N.
    ICMATE–CNR, Corso Stati Uniti 4, Padova, 35127, Italy.
    Baratto, C.
    CNR-INO SENSOR Laboratory, via Branze 45, Brescia, 25123, Italy.
    Kaunisto, K.
    Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, Tampere, FI-33101, Finland.
    Tkachenko, N.V.
    Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, Tampere, FI-33101, Finland.
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Information Engineering, University of Brescia, Via Branze 38, 9, Brescia, 25131, Italy;CNR-INO SENSOR Laboratory, via Branze 45, Brescia, 25123, Italy.
    Compact hematite buffer layer as a promoter of nanorod photoanode performances2016In: Scientific Reports, E-ISSN 2045-2322, Vol. 6, article id 35049Article in journal (Refereed)
    Abstract [en]

    The effect of a thin α-Fe2O3 compact buffer layer (BL) on the photoelectrochemical performances of a bare α-Fe2O3 nanorods photoanode is investigated. The BL is prepared through a simple spray deposition onto a fluorine-doped tin oxide (FTO) conducting glass substrate before the growth of a α-Fe2O3 nanorods via a hydrothermal process. Insertion of the hematite BL between the FTO and the nanorods markedly enhances the generated photocurrent, by limiting undesired losses of photogenerated charges at the FTO||electrolyte interface. The proposed approach warrants a marked improvement of material performances, with no additional thermal treatment and no use/dispersion of rare or toxic species, in agreement with the principles of green chemistry.

  • 49.
    Milan, Riccardo
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia, Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Selopal, Gurpreet Singh
    SENSOR Lab, Department of Information Engineering, University of Brescia, Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Epifani, Mauro
    Istituto per la Microelettronica e Microsistemi, IMM-CNR, via Monteroni, 73100 Lecce.
    Natile, Marta Maria
    Consiglio Nazionale delle Ricerche, Pisa, Universita Degli Studi di Padova.
    Sberveglieria, Giorgio
    SENSOR Lab, Department of Information Engineering, University of Brescia, Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Concina, Isabella
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    ZnO@SnO2 engineered composite photoanodes for dye sensitized solar cells2015In: Scientific Reports, E-ISSN 2045-2322, Vol. 5, article id 14523Article in journal (Refereed)
    Abstract [en]

    Layered multi-oxide concept was applied for fabrication of photoanodes for dye-sensitized solar cells based on ZnO and SnO2, capitalizing on the beneficial properties of each oxide. The effect of different combinations of ZnO@SnO2 layers was investigated, aimed at exploiting the high carrier mobility provided by the ZnO and the higher stability under UV irradiation pledged by SnO2. Bi-oxide photoanodes performed much better in terms of photoconversion efficiency (PCE) (4.96%) compared to bare SnO2 (1.20%) and ZnO (1.03%). Synergistic cooperation is effective for both open circuit voltage and photocurrent density: enhanced values were indeed recorded for the layered photoanode as compared with bare oxides (Voc enhanced from 0.39 V in case of bare SnO2 to 0.60 V and Jsc improved from 2.58 mA/cm2 pertaining to single ZnO to 14.8 mA/cm2). Improved functional performances of the layered network were ascribable to the optimization of both high chemical capacitance (provided by the SnO2) and low recombination resistance (guaranteed by ZnO) and inhibition of back electron transfer from the SnO2 conduction band to the oxidized species of the electrolyte. Compared with previously reported results, this study testifies how a simple electrode design is powerful in enhancing the functional performances of the final device.

  • 50.
    Milan, Riccardo
    et al.
    Department of Information Engineering, University of Brescia, Brescia, Italy; CNR-INO SENSOR Laboratory, Brescia, Italy; Schulich Faculty of Chemistry, Technion−Israel Institute of Technology, Haifa, Israel .
    Selopal, Gurpreet Singh
    Department of Information Engineering, University of Brescia, Brescia, Italy; Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, P. R. China; Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, Varennes, Canada.
    Cavazzini, Marco
    Institute of Molecular Science and Technology, ISTM-CNR, Milano, Italy .
    Orlandi, Simonetta
    Institute of Molecular Science and Technology, ISTM-CNR, Milano, Italy .
    Boaretto, Rita
    Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy .
    Caramori, Stefano
    Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy .
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Information Engineering, University of Brescia, Italy; CNR-INO SENSOR Laboratory, Italy.
    Pozzi, Gianluca
    Institute of Molecular Science and Technology, ISTM-CNR, Milano, Italy .
    Dye-sensitized solar cells based on a push-pull zinc phthalocyanine bearing diphenylamine donor groups: computational predictions face experimental reality2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, article id 15675Article in journal (Refereed)
    Abstract [en]

    Computational studies have suggested that the integration of secondary amine as donor groups in the structure of unsymmetrical zinc phthalocyanine (ZnPc) should have positive effects on photovoltaic performance, once the molecule is integrated as light harvester in dye sensitized solar cells (DSSCs). Aiming at obtaining experimental confirmation, we synthesized a peripherally substituted push-pull ZnPc bearing three electron donating diphenylamine substituents and a carboxylic acid anchoring group and integrated it as sensitizer in TiO2-based DSSCs. Detailed functional characterization of solar energy converting devices resulted in ruling out the original hypothesis. The causes of this discrepancy have been highlighted, leading to a better understanding of the conditions for an effective design of push-pull diarylamino substituted ZnPcs for DSSCs.

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