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  • 1.
    Aamir, Muhammad Haseeb
    et al.
    Ecole Nationale Supérieure de Géologie, GeoRessources, University of Lorraine, Vandoeuvre-lès-Nancy, France; University of Engineering and Technology, Lahore, Punjab, Pakistan.
    Gonçalves, Pedro Pereira
    Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Peñalolén, Santiago, Chile.
    Otsuki, Akira
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ecole Nationale Supérieure de Géologie, GeoRessources, University of Lorraine, Vandoeuvre-lès-Nancy, France; Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Peñalolén, Santiago, Chile; Neutron Beam Technology Team, RIKEN Center for Advanced Photonics, RIKEN, Wako, Saitama, Japan.
    Complementary results of non-destructive elemental assay and liberation analysis of waste printed circuit boards2024In: Non-Destructive Material Characterization Methods / [ed] Otsuki, Akira; Jose, Seiko; Mohan, Manasa; Thomas, Sabu, Elsevier , 2024, p. 767-782Chapter in book (Other academic)
  • 2.
    Abdel-Hameed, Amal Mohamed
    et al.
    Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
    Abuarab, Mohamed EL-Sayed
    Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Mehawed, Hazem Sayed
    Irrigation and Drainage Department, Agricultural Engineering Research Institute, Giza 12613, Egypt.
    Kassem, Mohamed Abdelwahab
    Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
    He, Hongming
    School of Geographic Sciences, East China Normal University, Shanghai 210062, China.
    Gyasi-Agyei, Yeboah
    School of Engineering and Built Environment, Griffith University, Nathan, QLD 4111, Australia.
    Mokhtar, Ali
    Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt; School of Geographic Sciences, East China Normal University, Shanghai 210062, China.
    Winter Potato Water Footprint Response to Climate Change in Egypt2022In: Atmosphere, ISSN 2073-4433, E-ISSN 2073-4433, Vol. 13, no 7, article id 1052Article in journal (Refereed)
    Abstract [en]

    The limited amount of freshwater is the most important challenge facing Egypt due to increasing population and climate change. The objective of this study was to investigate how climatic change affects the winter potato water footprint at the Nile Delta covering 10 governorates from 1990 to 2016. Winter potato evapotranspiration (ETC) was calculated based on daily climate variables of minimum temperature, maximum temperature, wind speed and relative humidity during the growing season (October–February). The Mann–Kendall test was applied to determine the trend of climatic variables, crop evapotranspiration and water footprint. The results showed that the highest precipitation values were registered in the northwest governorates (Alexandria followed by Kafr El-Sheikh). The potato water footprint decreased from 170 m3 ton−1 in 1990 to 120 m3 ton−1 in 2016. The blue-water footprint contributed more than 75% of the total; the remainder came from the green-water footprint. The findings from this research can help government and policy makers better understand the impact of climate change on potato crop yield and to enhance sustainable water management in Egypt’s major crop-producing regions to alleviate water scarcity.

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  • 3.
    Abdulhameed, Ali A.
    et al.
    Department of Reconstruction and Projects, University of Baghdad, Baghdad 10071, Iraq.
    Hason, Mahir M.
    Disaster Information Management Centre, Ministry of Science and Technology, Baghdad 10071, Iraq.
    Sharba, Amjad Ali K.
    Department of Civil Engineering, Mustansiriya University, Baghdad, Iraq.
    Hanoon, Ammar N.
    Department of Reconstruction and Projects, University of Baghdad, Baghdad 10071, Iraq.
    Amran, Mugahed
    Department of Civil Engineering, College of Engineering, Prince Sattam Bin Abdulaziz University, 11942 Alkharj, Saudi Arabia.; Department of Civil Engineering, Faculty of Engineering and IT, Amran University, 9677 Amran, Yemen.
    Magbool, Hassan M.
    Civil Engineering Department, College of Engineering, Jazan University, Jazan, Saudi Arabia.
    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.
    Experimental and environmental investigations of the impacts of wood sawdust on the performance of reinforced concrete composite beams2023In: Case Studies in Construction Materials, E-ISSN 2214-5095, Vol. 19, article id e02550Article in journal (Refereed)
    Abstract [en]

    It has been established that using recycled materials to replace some of the fine aggregates is a viable solution. Most researchers focused on the durability aspect of wood sawdust concrete, while less information is available on its structural performance. Therefore, this article aimed to investigate the performance of reinforced concrete beams fabricated from concrete with a partially replaced fine aggregate (FA) by wood sawdust (WS) in the range of 5–45 % (by weight). Six beams underwent 4-point bending tests till collapse. The beams' slump, density, compressive strength, cracking and failure mode, energy absorption, and economic and environmental aspects were studied. The findings showed that the failure region of sawdust concrete was more significant than the reference samples. Despite the compressive strength of the concrete containing different ratios of sawdust being reduced by about 7–30 %, the target compressive strength still has a limit of low to normal concrete grade. The results show that the increase in sawdust percentages decreased the acquired absorbed energy of the subjected load to reach failure. A cost reduction of 9 % and a cost index of 61 % is achieved using wooden sawdust-based concrete. By substituting sawdust for fine aggregate, the sustainability of sawdust concrete in terms of cost and environmental advantages may be improved. In addition, it is well-known that harnessing the transformative potential of industrial waste in concrete production not only minimizes landfill usage, but also promotes resource efficiency, reduces carbon emissions, and advances the circular economy, propelling designers, engineering and builders towards a greener and more sustainable future in the construction industry. According to the test findings, wood sawdust may be utilized to produce normal and low-strength structural concrete.

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  • 4.
    Abdulhameed, Isam Mohammed
    et al.
    University of Anbar, College of Engineering, Upper Euphrates Basin Developing Centre, Ramadi, Iraq.
    Sulaiman, Sadeq Oleiwi
    University of Anbar, College of Engineering, Dams and Water Resources Department, Ramadi, Iraq.
    Ahmed Najm, Abu Baker
    University of Anbar, College of Engineering, Dams and Water Resources Department, Ramadi, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Optimising water resources management by Using Water Evaluation and Planning (WEAP) in the West of Iraq2022In: Journal of Water and Land Development, ISSN 1429-7426, no 53, p. 176-186Article in journal (Refereed)
    Abstract [en]

    Iraq has been suffering from decreasing Euphrates discharge due to the construction of dams within upstream countries and the use of surface irrigation systems. The country is facing a problem with meeting the increasing demand for water as a result of population growth and development in the industrial and agricultural sectors. Therefore, a simulation modelling was applied for western Iraq (Ramadi city as a case study) using the Water Evaluation and Planning System (WEAP) for the period 2018–2035. This research follows a four-step approach that involves: (i) evaluating the available water of the Euphrates River under declined water imports caused by the construction of dams in Turkey and Syria, (ii) assessing present and future water demands of the domestic, industrial, and agricultural sectors, (iii) improving water productivity (WP) by means of saving more water, (iv) estimating the economic returns under improved water use. The results showed that Iraq would face a serious problem in the coming years, represented by the limited storage of Haditha Dam, which is considered the strategic water storage site for the central and southern regions of Iraq. The study indicated the necessity of finding alternative sources of water supply by adopting new water management strategies to reduce the water deficit. 

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  • 5.
    Abrahamsson, Filip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Leaching of Pyrrhotite from Nickel Concentrate2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Non-oxidative acid leaching of pyrrhotite from Kevitsa’s Ni-concentrate and methods to recover by-products, have been investigated. Selective dissolution of pyrrhotite (Fe1-xS, 0<x<0.25) can enrich the content of the valuable metals, such as Ni and Co, in the final concentrate and will reduce the amount of Fe and S sent to the smelters. The pyrometallurgical smelting of leached concentrate will thus give less formation of smelter by-products in form of slag and SO2. The leaching was studied through an experimental design plan with parameter settings of  38.8% to 57.8% H2SO4 and temperatures from 60 to 100°C. The best results were obtained in experiments carried out at the lower experimental range. Leaching at 60°C with an initial acid concentration of 38.8% H2SO4 was found sufficient to selectively dissolve most of the pyrrhotite; leaving an enriched solid residue. A QEMSCAN analysis of the solid residue confirmed that most of the pyrrhotite had been dissolved and showed that pentlandite was still the main Ni-mineral. Chemical assays showed that more than 95% of the Ni, Co, and Cu remained in the final residue.

       The utilized leaching process generates by-products, in the form of large quantities of Fe2+ in solution and gaseous H2S. To recover Fe2+, crystallization of iron(ii) sulfate (FeSO4∙nH2O) from leach solution through cooling have been studied. The crystallized crystals were further dehydrated into the monohydrate (FeSO4∙H2O) through a strong sulfuric acid treatment (80%H2SO4). XRD analysis confirmed that FeSO4∙H2O was the main phase in the final crystals, and a chemical analysis showed a Fe content of about 30%, 1.5% Mg, 0.4% Ca, and 0.2% Ni.

       The possibility to leach the concentrate by circulating the acidic solution from the crystallization stage has been tested. The recirculation of the solution showed no negative effects, as the recoveries of elements and chemical assays of the final solid residue were found to be similar to the obtained assay when the concentrate was leached in a fresh solution.

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  • 6.
    Afzelius, Alissa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Från schaktmassa till ballastprodukt: Om möjligheten att uppgradera schaktmassor med våtsiktning2020Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [sv]

    Byggsektorn är den bransch (exklusive gruvnäringen) som står för störst andel uppkommen avfall i Sverige, framförallt i form av schaktmassor.

    Marknaden för återvunna schaktmassor är idag begränsat, dels på grund av otydlig lagstiftning kring återvinning, dels på grund av massornas varierande innehåll. Uppgrävda överskottsmassor från gamla industrimarker kan innebära förhöjda föroreningshalter vilket leder till dyra behandlingar för köpare. Det är heller inte lika lätt att styra den geotekniska kvaliteten hos produkten när råvaran varierar i sammansättning. Vidare kommer produkter av återvunnet ursprung troligtvis vara utsatta för hårdare kontroller än produkter framtagna av jungfruligt material. Den större risken, tillsammans med få incitament att prioritera återvunna material i byggen försvårar säljbarheten.

    Syftet med det här examensarbetet har varit att undersöka ifall schaktmassor kan uppgraderas till högkvalitativa konstruktions- eller anläggningsprodukter som efterfrågas av marknaden. Swerocks våtsiktsanläggning i Malmö användes som studieobjekt och undersökningen begränsades till två fraktioner, sand i storlek 0–4 mm och grus i storlek 4–16 mm.

    Arbetet har utförts genom litteraturstudie, intervjuer samt analysering av provresultat, där tre forskningsfrågor kring användning, kravbild och kvalitet har legat som grund för undersökningarna.

    Resultatet visar att flera aktörer ställer sig positiva till ökad användning av återvunna ballastprodukter så länge dess kvalitet kan säkerställas, främst med avseende på innehållet av föroreningar. Ett stort hinder är den befintliga avfallslagstiftningen och dess avsaknad av tydliga kriterier för när avfallet kan omklassas till produkt.

    Det finns användningsområden som lämpar sig bättre för ett schaktmaterial av varierande ursprung, där de geotekniska materialkraven är färre. Studien visade att uppgraderat material kan uppfylla krav för utvalda applikationer inom fyllning och dränering enligt AMA Anläggning 17. Främsta krav där är på kornstorleksfördelning och sortering, vilket våtsikten klarar bra. Däremot gör AMA:s nuvarande materialtypsindelning att återvunna material förbises. Detta trots att de kan ha motsvarande egenskaper likt de efterfrågade materialtyperna. Vidare omfattas både fyllnad- och dränerandematerial av ballaststandard SS-EN 132 42 vilket gör att produkterna måste prestandadeklareras och CE-märkas enligt lag. Trots byggproduktskravet är detta något som ofta förbises hos både köpare och producenter.

    Gällande de kemiska innehållet hos det våtsiktade materialet visade den här studien på stor spridning samt föroreningshalter överstigande haltnivåer för MRR för PAH, koppar, bly och oljor i både sand och grus. En trend av ökande föroreningshalter i produkter i samband med att mer förorenat material togs in för behandling kunde även anas. Sammantaget innebär det en minskad säljbarhet av materialet trots att det uppfyllde krav enligt AMA 17. Antingen behöver fler behandlingssteg tilläggas, med ökade produktionskostnader som följd, eller mer restriktivt urval av vilka massor som tas in för behandling

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  • 7.
    Agües Paszkowsky, Núria
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Data Analysis of Earth Observation Data from Copernicus Satellites2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Open Data Cubes are platforms that contain open source satellite data and provide analysis tools for governments or organizations. The Swedish version is known as Swedish Space Data Lab (SSDL) and this master thesis was a part of it, providing the first analysis tools of the SSDL. Within a smaller project in the SSDL a drought analysis was done for the region of Mälardalen. The thesis work consisted on developing data analysis methods using packages for machine learning and statistical analysis in Python and Jupyter Notebooks. The drought analysis consisted of a two-year comparison between 2018 and 2019 due to limitations on the data availability. It was found that first year was drier than the second. However, longer time series would be needed in order to observe trends related to possible changes in the climate.

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  • 8.
    Ahmed, Amber
    et al.
    Vattenfall R&D, Stockholm, Sweden.
    Etherden, Nicholas
    Vattenfall R&D, Stockholm, Sweden.
    The potential for balancing the Swedish power grid with residential home batteries2021In: CIRED 2021 - The 26th International Conference and Exhibition on Electricity Distribution, Institution of Engineering and Technology, 2021, p. 2104-2108, article id 0713Conference paper (Refereed)
    Abstract [en]

    This paper presents the potential for prosumer batteries coupled to PV units to cover the national frequency balancing needs in Sweden. PV coupled residential batteries are found to be profitable with today's prices, if granted access to balancing markets. Simulations are based on national targets for solar PV production in 2040 (5-10 TWh, 5-10% of electric consumption) and current residential PV share of total installed PV capacity. In the study battery attachment rate was 50% and 15% of single family houses were equipped with 10 kW PV installation with a battery capacity of 6 kW / 7.68 kWh. In total, the battery PV systems constituted 25% of total installed capacity of PV in 2040. The results showed that 20% of the aggregated batteries capacity is sufficient to provide around 70-100% of each of the frequency reserves individually. The highest savings are gained for the households when both the primary frequency reserves, FCR-N and FCR-D, are provided by the aggregated batteries together with increasing the PV self-consumption, peak shaving and energy arbitrage. When providing frequency support the PV system payback time was reduced from 14 to 11 years when equipped with battery, compared to only installing PV.

  • 9.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kaasalainen, Hanna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Sweco.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nyström, Elsa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nigéus, Susanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    StopOx: Utilization Of Industrial Residuals For Prevention Of Sulfide Oxidation In Mine Waste2019Report (Other academic)
    Abstract [en]

    This report is the outcome of the SIP STRIM project

    StopOx-Utilization of industrial residuals for prevention of sulfide oxidation in mine waste implemented at Applied geochemistry, Luleå University of Technology running from 2015 to 2018. Boliden Mineral has been partner and co-funder of the project. Other partners in the project were Cementa, Dragon Mining, MEROX, Nordkalk, and SP Processum. The overall aim of the project was to develop prevention technologies to reduce the sulfide oxidation in mine waste, during and after operation, and thereby reduce the generation of acid mine drainage. The StopOx project has been focusing on sulfidic mine waste from the Boliden area which were disposed of and are causing acid mine drainage or have the potential. Industrial residues/products were supplied by BillerudKorsnäs, Cementa, MEROX, and Nordkalk. The report consists of chapters based on three subprojects.

    Chapter 1. Introduction

    Chapter 2. Inhibition technology with aim to minimize waste rock oxidation during operations by using residues from other industries (passivation of sulfidic surfaces by the formation of secondary minerals)

    Chapter 3. The suitability of green liquor dregs as substitutes for or additives to till in a sealing layer as part of a cover system

    Chapter 4. Weathering of waste rock under changing chemical conditions

    The research described in chapters 2 and 3 was performed by Ph.D. students and will continue until 2021, while the subproject in chapter 2 ended in 2018.

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  • 10.
    Alam, Md Tabrez
    et al.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    Raj, Aashna
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Singh, Lalan K.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    Gupta, Anoop K.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    A comparative analysis on charging performance of triplex-tube heat exchanger under various configurations of composite phase change material2024In: Thermal Science and Engineering Progress, E-ISSN 2451-9049, Vol. 51, article id 102655Article in journal (Refereed)
    Abstract [en]

    In present work, the melting performance of triplex-tube latent heat thermal energy storage (LHTES) unit was numerically studied using equal volumes of PCM and metal foam composite PCM (CPCM) in various arrangements. For the n-eicosane (as PCM), the study was conducted at the fixed Rayleigh number (Ra) = 4.08x107, Prandtl number (Pr) = 62.9, and Stefan number (Ste) = 0.14. The results showed that positioning the metal foam on the bottom side and distributing segmented CPCM with alternating PCM zones effectively improved the system performance. Moreover, this also prevents the overheating of thermal layers in the LHTES unit. While the model labelled M2 exhibited the highest economic efficiency among all isotropic models, its low dimensionless thermal energy storage (TES) density (i.e., q’ ∼ 0.6) led this study to focus on models falling under the category having a TES density of ∼ 0.8. Compared to a pure PCM model, the configurations under equal volume ratio category demonstrated up to ∼ four times higher TES rate (p’) and the significant reduction of ∼ 75 % in melting time. The optimized isotropic model achieved the highest TES rate per unit cost with peak value of ∼ 3 at a price ratio (N) of 1. Lastly, the testing of metal foam anisotropy on the chosen design showed a substantial increase in melting/heat storage rates. The largest drop of ∼ 33 % in the total melting time was noticed for model M2 as compared to isotropic case.

  • 11.
    Al-Chalabi, Hussan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Al-Douri, Yamur K.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Lundberg, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Time Series Forecasting using ARIMA Model: A Case Study of Mining Face Drilling Rig2018In: ADVCOMP 2018: The Twelfth International Conference on Advanced Engineering Computing and Applications in Sciences / [ed] Claus-Peter Rückemann; Ahmad Rafi Qawasmeh, International Academy, Research and Industry Association (IARIA), 2018, p. 1-3Conference paper (Refereed)
    Abstract [en]

    This study implements an Autoregressive Integrated Moving Average (ARIMA) model to forecast total cost of a face drilling rig used in the Swedish mining industry. The ARIMA model shows different forecasting abilities using different values of ARIMA parameters (p, d, q). However, better estimation for the ARIMA parameters is required for accurate forecasting. Artificial intelligence, such as multi objective genetic algorithm based on the ARIMA model, could provide other possibilities for estimating the parameters. Time series forecasting is widely used for production control, production planning, optimizing industrial processes and economic planning. Therefore, the forecasted total cost data of the face drilling rig can be used for life cycle cost analysis to estimate the optimal replacement time of this rig.

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  • 12.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Hamodi, Hussan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Data imputing using generic algorithms (GA)2017In: Mine Planning and Equipment Selection (MPES 2017): Proceeding of the 26th International Symposium on Mine Planning and Equipment Selection Luleå, Sweden, August 29-31, 2017 / [ed] Behzad Ghodrati, Uday Kumar, Håkan Schunnesson, Luleå: Luleå tekniska universitet, 2017, p. 205-208Conference paper (Refereed)
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  • 13.
    Alenius, Christoffer
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Dynamic simulation and techno-economicevaluation of a seasonally insulated hybridgreenhouse concept for subarctic climates2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish authority for social protection and preparedness, MSB, believes that the self-sufficiency of the country must be strengthened in order to be prepared for a crisis. Presently, Sweden is only 50% self-sufficientwhich is very low compared to its neighboring countries; and it is worse the further north you go. One solution could be to increase the production of food, for example vegetables, but the number of greenhouse operations in Sweden are already dwindling due to the inhospitable climate, which makes it expensive to keep up all-year cultivations. Norrbotten, the northernmost part of Sweden, has the highest heat demand for greenhouses in the country. One option could be to set up operation in heavily insulated buildings and rely on artificial lighting, in so called plant factories. Though, these are expensive, electricity intensive and have generally lower yields.

    This report will cover the development, validation, and performance of a dynamic model of a new greenhouse concept, developed for subarctic climates. The greenhouse is meant to utilize the strengths of both glass houses and plant factories to optimize the profits for a year-round operation. This, to find an alternative solution to the self-sufficiency problem in the winter. In addition to this, the optimal glaze for the climate shell had to be determined and what type of lighting technology would be the most viable. The hybrid greenhouse is a gableroof greenhouse with insulated north, west and east walls designed for microgreen cultivation, Lactuca Sativa. The interesting part of the greenhouse is that it has a retractable insulation cover, of mineral wool, inside of the climate shell. This was meant to heavily insulate the greenhouse during the winter seasons, though it would not let any sunlight in. This meant that the hybrid greenhouse must rely on artificial lighting in the winter but will get a reduced heating demand. When the outdoor temperature rises and the sun becomes more visible,the cover can be retracted to utilize sunlight for heating and photosynthesis. The cost between heating and electricity usage and the profits from the amount of yield will therefore vary depending on how long the coveris opened or closed and an optimal cost solution should be found somewhere within that variation. The model was created using Simulink version 10.6, which could simulate the heat demand, the humidity level, CO2-concentration, and the yield of the greenhouse.

    The models heat demand and yield was validated againsta greenhouse in Nikkala, Sweden, owned by Norrskenstomater. The model produced a standard deviation of 24.6 MWh over three months but it overestimated the yearly yield of Norrskenstomater with about 40%. To make the sure the hybrid greenhouse performed effectively, the amount of leakage must be minimized, as this has a significant impact on the heat demand. The hybrid greenhouse needs lighting alternatives with substantial active cooling (90% of the lamps input power), such as light emitting diodes. High pressure sodium lamps produce too much heat and can not be used at all. For yearly simulations, the cover was set to close for certain amounts of months during the year. The highest yearly profit, highest net present value (4.8 MSEK) and lowest payback time (3.5 years) could be achieved if the cover were closed between October and March. The best glazing material in terms of economic performance was 4 mm glass followed by 16 mm plastic panels in acrylic. The hybrid greenhouse could even outperform a greenhouse that did not cultivate during the winter. The hybrid greenhouse seems to get rid of the negative impacts of winter cultivation and is therefore considereda viable alternative as a cultivation system for subarctic climates. 

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  • 14.
    Ali, Salamat
    et al.
    School of Materials and Energy, Lanzhou University, Lanzhou 730000, China.
    Ahmad, Awais
    Department of Chemistry, The University of Lahore, Lahore, 54590, Pakistan; Departamento de Química Orgánica, Universidad de Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie (C3), E-14014 Córdoba, Spain.
    Hussain, Iftikhar
    Department of Mechanical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
    Shah, Syed Shoaib Ahmad
    Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, Islamabad 44000, Pakistan.
    Ali, Shafqat
    Department of Physics, Shah Abdul Latif University Khairpur, Khairpur, Sindh, 66202, Pakistan.
    Ali, Asad
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Javed, Muhammad Sufyan
    Department of Chemistry, The University of Lahore, Lahore, 54590, Pakistan; School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China.
    Experimental and Theoretical Aspects of MXenes-Based Energy Storage and Energy Conversion Devices2023In: Journal of Chemistry and Environment, E-ISSN 2959-0132, Vol. 2, no 2, p. 54-81Article, review/survey (Refereed)
    Abstract [en]

    Transition metal carbides, nitrides, and carbonitrides (MXenes) have become an appealing framework for developing various energy applications. MXenes with van der Waals (vdW) interactions are facile, highly efficient, affordable, and self-assembled features that improve energy density. MXenes exhibit large surface area, high electric conductivity, and excellent electrochemical characteristics for various energy applications. This review summarizes and emphasizes the current developments in MXene with improved performance for energy storage or conversion devices, including supercapacitors (SCs), various types of rechargeable batteries (RBs), solar cells, and fuel cells. We discuss the crystal structures of MXenes properties of MXenes and briefly discuss them for different types of energy applications. Finally, the critical outlook and perspective for the MXene progress for applications in energy applications are also described.

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  • 15.
    Alkaradaghi, Karwan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Department of Geology, College of Science, Sulaimani University, 460013, Sulaimaniyah, Iraq; Kurdistan Institution for Strategic Studies and Scientific Research, 460013, Sulaimaniyah, Iraq.
    Ali, Salahalddin S.
    Department of Geology, College of Science, Sulaimani University, 460013, Sulaimaniyah, Iraq; Komar University of Science and Technology, 460013, Sulaimaniyah, 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.
    Landfill Site Selection Using GIS and Multi-criteria Decision-making AHP and SAW Methods: A Case Study in Sulaimaniyah Governorate, Iraq2022In: Research Developments in Geotechnics, Geo-Informatics and Remote Sensing: Proceedings of the 2nd Springer Conference of the Arabian Journal of Geosciences (CAJG-2), Tunisia 2019 / [ed] Hesham El-Askary; Zeynal Abiddin Erguler; Murat Karakus; Helder I. Chaminé, Springer Nature, 2022, p. 289-292Conference paper (Refereed)
    Abstract [en]

    Lack of land for waste disposal is one of the main problems facing urban areas in developing countries. The Sulaimaniyah Governorate, located in Northern Iraq, is one of the main cities of the country in the Kurdistan Region, covering an area of 2400 km2. Currently, there is no landfill site in the study region that meets the scientific and environmental requirements, and the inappropriate dumping of solid waste causes adverse effects to the environment, economic and urban aesthetic. To overcome this phenomenon, it is crucial to suggest a landfill site, even in countries that recycle or burn their waste to protect the environment. Landfill sites should be carefully selected taking into account all regulations and other restrictions. The integration of geographic information systems and the multi-criteria decision analysis were used in this study to select suitable landfill locations in the region. To this end, thirteen layers prepared according to their importance including slope, geology, land use, urban area, villages, rivers, groundwater, slope, elevation, soil, geology, road, oil and gas, land use, archaeology and power lines. Two different methods (simple additive weighting and analytic hierarchy process) were implemented in a geographical information system to obtain the suitability index map for candidate landfill sites, where all these conditions satisfied the scientific and environmental criteria adopted in this study. The comparison of the maps resulting from these two different methods demonstrates that both methods produced consistent results.

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  • 16.
    Alkaradaghi, Karwan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Department of Geology, College of Science, Sulaimani University, Sulaimaniyah, Iraq. Kurdistan Institution for Strategic Studies and Scientific Research, Sulaimaniyah, Iraq.
    Ali, Salahalddin Saeed
    Department of Geology, College of Science, Sulaimani University, Sulaimaniyah, Iraq. Komar University of Science and Technology, Sulaimaniyah, Iraq. Komar Research Center, Sulaimaniyah, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Ali, Tara
    Kurdistan Institution for Strategic Studies and Scientific Research, Sulaimaniyah, Iraq.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Quantitative Estimation of Municipal Solid Waste in Sulaimaniyah Governorate, Iraq2021In: Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (2nd Edition): Proceedings of 2nd Euro-Mediterranean Conference for Environmental Integration (EMCEI-2), Tunisia 2019 / [ed] Mohamed Ksibi; Achraf Ghorbal; Sudip Chakraborty; Helder I. Chaminé; Maurizio Barbieri; Giulia Guerriero; Olfa Hentati; Abdelazim Negm; Anthony Lehmann; Jörg Römbke; Armando Costa Duarte; Elena Xoplaki; Nabil Khélifi; Gilles Colinet; João Miguel Dias; Imed Gargouri; Eric D. Van Hullebusch; Benigno Sánchez Cabrero; Settimio Ferlisi; Chedly Tizaoui; Amjad Kallel; Sami Rtimi; Sandeep Panda; Philippe Michaud; Jaya Narayana Sahu; Mongi Seffen; Vincenzo Naddeo, Springer, 2021, p. 265-270Conference paper (Refereed)
    Abstract [en]

    As the world’s population has grown, waste generation has increased rapidly. Solid waste management requires a greater knowledge of the composition, generation quantity, physical properties, and impacts of economic aspects. This paper clarified the status of municipal solid waste management across Sulaimaniyah governorate and presented a comprehensive overview and implication of poor solid waste management in the study area. The core aspects covered were the future estimations of the cumulative solid waste amount with population growth by 2040 using brief calculations of the waste generation rate from 2016. The results revealed that the daily per capita waste generation in the Sulaimaniyah governorate is 1.32 kg by 2040, a cumulative solid waste of about 10,445,829 tons, and an estimated volume of 9,146,368 m3 which will be required for the disposal site in the future. 

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  • 17.
    Alkhaled, Lama
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Fei, Ng Yee
    Asia Pacific University, Faculty of Computing, Kuala Lumpur, Malaysia.
    Automated Invoice Processing System2023In: 2023 IEEE International Conference on Industrial Engineering and Engineering Management, IEEM 2023, IEEE, 2023, p. 0188-0192Conference paper (Refereed)
  • 18.
    Almgren, G.
    Luleå University of Technology.
    Lulea Colleges And Mining Engineering1977In: JERNKONTORETS ANNALER, Vol. 161, no 3, p. 58-60Article in journal (Refereed)
  • 19.
    Altuntov, Firdevs Kübra
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Skawina, Bartlomiej
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Greberg, Jenny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Engberg, H
    General Manager Mining Technology, Loussavaara-Kiirunavaara Aktiebolag (LKAB), Kiruna Norrbotten 981 86, Sweden.
    Niia, I
    Mine Planner, Loussavaara-Kiirunavaara Aktiebolag (LKAB), Kiruna Norrbotten 981 86, Sweden.
    An initial review of conceptual alternative layouts for production areas in Kiirunavaara mine2023In: Underground Operators Conference 2023: Conference Proceedings, The Australasian Institute of Mining and Metallurgy , 2023, p. 200-208Conference paper (Refereed)
  • 20.
    Amini, Hasel
    et al.
    Faculty of Mining, Petroleum and Geophysics, University of Shahrood, Shahrood, Iran.
    Torabi, Seyed Rahman
    Faculty of Mining, Petroleum and Geophysics, University of Shahrood, Shahrood, Iran.
    Hoseinie, Seyed Hadi
    Department of Mining Engineering, Hamedan University of Technology, Hamedan, Iran.
    Ghodrati, Behzad
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    RAM analysis of earth pressure balance tunnel boring machines: A case study2015In: International Journal of Mining and Geo-Engineering, ISSN 2345-6930, Vol. 49, no 2, p. 173-185Article in journal (Refereed)
    Abstract [en]

    Earth pressure balance tunnel boring machines (EPB-TBMs) are favorably applied in urban tunneling projects. Despite their numerous advantages, considerable delays and high maintenance cost are the main disadvantages these machines suffer from. Reliability, availability, and maintainability (RAM) analysis is a practical technique that uses failure and repair dataset obtained over a reasonable time for dealing with proper machine operation, maintenance scheduling, cost control, and improving the availability and performance of such machines. In the present study, a database of failures and repairs of an EBP-TBM was collected in line 1 of Tabriz subway project over a 26-month interval of machine operation. In order to model the reliability of the TBM, this machine was divided into five distinct subsystems including mechanical, electrical, hydraulic, pneumatic, and water systems in a series configuration. According to trend and serial correlation tests, the renewal processes were applied, for analysis of all subsystems. After calculating the reliability and maintainability functions for all subsystems, it was revealed that the mechanical subsystem with the highest failure frequency has the lowest reliability and maintainability. Similarly, estimating the availability of all subsystems indicated that the mechanical subsystem has a relatively low availability level of 52.6%, while other subsystems have acceptable availability level of 97%. Finally, the overall availability of studied machine was calculated as 48.3%.

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  • 21.
    Amofah, Lea Rastas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bhattacharya, Prosun
    Department of Land and Water Resources Engineering, Royal Institute of Technology (KTH), 100 44, Stockholm, Sweden.
    The influence of temperature, pH/molarity and extractant on the removal of arsenic, chromium and zinc from contaminated soil2011In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 11, no 8, p. 1334-1344Article in journal (Refereed)
    Abstract [en]

    Purpose: Normal soil washing leave high residual pollutant content in soil. The remediation could be improved by targeting the extraction to coarser fractions. Further, a low/high extraction pH and higher temperature enhance the pollutant removal, but these measures are costly. In this study, the utility of NaOH, oxalate-citrate (OC) and dithionite-citrate-oxalate (DCO) solutions for extracting of arsenic, chromium and zinc from contaminated soil were assessed and compared. In addition the effects of NaOH concentration and temperature on NaOH extractions, and those of temperature and pH on OC and DCO extractions, were evaluated. Materials and methods: A two-level, full-factorial design with a centre point was implemented. Two factors, concentration and temperature,were evaluated in NaOH extractions, and pH and temperature for OC and DCO solutions. In all cases, the extraction temperature was 20°C, 30°C and 40°C. The studied NaOH concentrations were 0.05, 0.075 and 0.1 M. The pH in OC solutions was 3, 5 and 7, and in DCO solutions, 4.7, 6.3 and 6.7. Water-washed and medium coarse soil fraction of arsenic, chromium and zinc contaminated soil was agitated for 15 min with the extraction solution. Results and discussion: In NaOH extractions, the temperature and (less strongly) NaOH concentration significantly affected As and Cr mobilisation, but only the latter affected Zn mobilisation. Both pH and temperature significantly (and similarly) influenced As and Cr mobilisation in OC extractions, while only the pH influenced Zn mobilisation. In contrast, the extraction temperature (but not pH) influenced As, Cr and Zn mobilisation in DCO extractions. Conclusions: For all extractants, mobilisation was most efficient at elevated temperature (40°C). None of the extractants reduced the soil's As content to below the Swedish EPA's guideline value. Use of DCO is not recommended because dithionite has a short lifetime and residual arsenic contents in DCO-extracted soil are relatively high. Instead, sequential extraction with NaOH followed by OC solutions (affording significant reductions in As, Cr and Zn levels in the soil with short extraction times) at 40°C is recommended.

  • 22.
    Amulya, K.
    et al.
    National University of Ireland, Galway, Ireland.
    Dahiya, Shikha
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Venkata Mohan, S.
    Bioengineering and Environmental Sciences Lab, Department of Energy and Environmental Engineering (DEE), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, Telangana, India.
    Building circular bio-based economy through sustainable waste management2023In: Bioremediation and Bioeconomy: a Circular Economy Approach / [ed] Majeti Narasimha Vara Prasad, Elsevier, 2023, 2, p. 639-666Chapter in book (Other academic)
  • 23.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Aktivitet: Seminarium om användning av slam och aska som tätskikt på deponi2005Conference paper (Other (popular science, discussion, etc.))
  • 24.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Implementing a lab-developed liner recipe in a full scale cover construction: challenges, setbacks and success2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 40-Conference paper (Refereed)
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  • 25. Andreas, Lale
    Langzeitemissionsverhalten von Deponien für Siedlungsabfälle in den neuen Bundesländern2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [de]

    Langzeitemissionsverhalten von Deponien für Siedlungsabfälle in den neuen BundesländernZusammenfassungZiel der vorliegenden Arbeit war die Beschreibung des Langzeitverhaltens von DDR-Depo­nien unter besonderer Berücksichtigung der Emissionen auf dem Sickerwasserpfad.Die Beschreibung umfaßte die untersuchten Deponiestandorte, die Deponierungspraxis in der DDR, cha­rak­teristische Eigenschaften der abgelager­ten Abfälle sowie der nach mehrjähriger Lage­rungs­zeit ausgekofferten Altabfallproben, die Sickerwasseremissionen der Deponie Döbeln-Hohenlauft, das Auslaugverhalten der Altabfälle in Mehrfachelutionsversuchen und die Sickerwasser- und Gas­emis­­sionen der Deponiesimulationsversuche.Als charakteristische Eigenschaften der DDR-Deponien, die für das Emissionsverhalten von Be­deu­tung sind, wurden folgende Punkte herausgearbeitet:langsames Deponiewachstum,fehlende oder sehr geringe Verdichtung,vergleichsweise intensive aerobe Prozesse zu Beginn der Ablagerung.Bedingt dadurch wurde ein Großteil der biologisch abbaubaren Bestandteile des Abfalls sehr schnell umgesetzt und trägt nicht zum langfristigen Emissionsverhalten bei.Die Abfallzusammensetzung von DDR-Altabfällen ist gekennzeichnet durch:hohe Anteile von Feinmaterial (bis zu 70 Masse% sind < 8mm),hohe Anteile mineralischer Stoffe, wie Aschen und Bauschutt,hohe Salzgehalte (Sulfat, Alkalien, Erdalkalien),eine hohe Säurepufferkapazität undgeringe Anteile organischer Abfälle.Dies führt zu einem wenig reaktiven Deponiekörper und den bei den meisten alten DDR-Depo­nien zu beobachtenden geringen Emissionen. Die wesentlichen Emissionen erfolgen auf dem Sicker­was­serpfad, die Hauptkomponente dabei sind anorganische Salze. Hinsichtlich der Zu­sam­mensetzung kön­nen die DDR-Deponien am ehesten mit Asche-/Schlackedeponien verglichen werden, die in Zu­kunft den wohl wichtigsten Deponietyp in Deutschland darstellen werden.Auf der Basis der Untersuchungen zur Feststoffzusammensetzung der Abfälle und ihres Auslaug- und Emissionsverhaltens wurden desweiteren Prozesse diskutiert, die in DDR-De­po­nien in der Ver­gan­genheit stattgefunden haben können bzw. die zukünftig möglich sind. Hierbei sind zu nennen:die Auslaugung von Salzen,Sulfatreduktion,Karbonatanreicherung im Feststoff.Mittels multivariater Datenanalyse konnte eine Einordnung der Deponieprozesse in eine späte an­aero­be Phase mit Tendenz zu semi-aeroben Prozessen hin vorgenommen werden. Die methodischen Unterschiede zwischen Mehrfachelutions- und DSR-Versuchen wurden genutzt, um biologische Prozesse in den DSR zu identifizieren und bewerten. Im Ergebnis der Untersuchungen in Deponiesimulationsreaktoren wurden langfristige Emissions­poten­tiale EP und notwendige Nachsorgezeiträume bis zum Erreichen von Grenzkonzentrationen im Sickerwasser abgeschätzt. Sie sind in Tabelle 1 als Medianwerte zusammengefaßt dargestellt. Die Auswertung langjähriger Sickerwassermeßreihen der Deponie Döbeln-Hohen­lauft bestätigte die Repräsentativität der DSR-Versuche und unterstützt die getroffenen Progno­sen.Tabelle 1 Notwendige Zeiträume TE bis zum Erreichen von umweltverträglichen Konzentra­tio­nen cE im Sickerwasser von DDR-Altdeponien [a] Grenzkonzen­tration cEDSR-EP(W-F ® ∞) Stoffaustrag FE bis cE [g/kg] W-FE bis cE [l/kg TS] Zeitraum TE bis cE [a]CSB200 mg/l0,60,20,557TOC 100 mg/l0,150,040,334NKj 70 mg/l0,250,091,2144Cl‾100 mg/l0,70,61,4167SO42‾250 mg/l2,72,61,5180 Die längsten Zeiträume sind für den Austrag von Stickstoff und Salzen, insbesondere des Sulfats, notwendig. Die Dauer wird im wesentlichen durch folgende Faktoren beeinflußt:Abfallzusammensetzung (Anteil neuer Abfälle auf den alten DDR-Deponien)WasserhaushaltLuftzutritt, Oxidation.Ein Ausblick auf das veränderte Emissionsgeschehen der nach 1990 weiter ­betriebenen DDR-Deponien zeigt, daß sich durch die Veränderungen in Ab­fall­zusam­men­setzung und Abla­ge­rungs­praxis das Deponieverhalten deutlich verschlechtert hat, und eine Annäherung des Emis­­sions­­niveaus an die Verhältnisse von Siedlungsabfalldeponien der 70er/80er Jahre in den alten Bun­des­län­dern zu verzeichnen ist.Die erwarteten Nachsorgezeiträume gehen z. T. deutlich über heute in der Praxis diskutierte Werte hinaus. Um den Zeitrahmen bis zum Erreichen umweltverträglicher Sickerwasserkonzentrationen so zu verkürzen, daß die bei der Deponierung anfallenden Probleme von der gleichen Generation gelöst werden, die sie verursacht hat, sind aktive Maßnahmen zur Emissionsminimierung unbedingt not­­wendig.

  • 26. Andreas, Lale
    et al.
    Bilitewski, Bernd
    University of Technology Dresden, Pirna.
    Effects of waste quality and landfill technology on the long-term behaviour of municipal landfills1999In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 17, no 6, p. 413-423Article in journal (Refereed)
    Abstract [en]

    The pollution potential of old municipal landfills of the former German Democratic Republic (GDR) is not as bad as expected, even taking into consideration that most lack environmental protection systems. Compared with specific conditions in the former GDR (such as production and consumption), the disposal of waste and the long-term behaviour of landfills clearly differs from that in the old German federal states. Low quantities of deposited waste created slowly growing landfills, and therefore led to rapid degradation processes still in the aerobic milieu. As a result of the increasing similarity of waste quantities and composition in the new and old federal states after 1990, waste deposited today can be expected to have similar long- term behaviour and emissions as existing old Federal Republic of Germany (FRG) landfills which were operating during the 1970s and 1980s.

  • 27.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Diener, Silvia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hydraulic performance of a land-fill top cover based on steel slag2014In: Sardinia 2013: 14th International Waste Management and Landfill Symposium, Forte Village, S. Margherita di Pula (CA), Italy, 30 September - 4 October 2013 ; CD-ROM: Symposium proceedings / [ed] Raffaello Cusso, Cagliari: CISA, Environmental Sanitary Engineering Centre , 2014Conference paper (Other academic)
    Abstract [en]

    The steel industry is expanding and following the amount of produced steel, more and more by-products and residuals are generated. About 17.6 million tonnes of steel slags arise in Europe every year. In Sweden about 18 % of the iron- and steelmaking slags are landfilled (Jernkontoret, 2012). One application for steel slags are landfill covers where large amounts of virgin materials are needed. The legal requirement in Sweden is directed towards the maxi¬mum amount of lea¬chate generated at the bottom of the landfill: < 5 and < 50 l (m2*a)-1 for landfill class 1 and 2, respec¬ti¬vely. To secure these demands, a layer of low permeability is needed to reduce water infiltration. The hydraulic load of this layer ought to be controlled by a protective water balance layer and an effective drainage layer.Previous investigations indicate that steel slags can be used as construction material for both liner and drainage layer (Herrmann et al., 2010). In order to verify this in full scale, five tests areas (A1-5) were constructed at a municipal landfill in Sweden between 2005 and 2011. The areas were designed using different mixtures of steel slags from the local steel company in the liner. The purpose of this study was to evaluate the hydraulic performance of the cover during the first years after installation.The design of the cover construction was varied like this: a mixture of 50 % electric arc furnace slag (EAFS) and 50 % ladle slag (LS) was tested as liner material in the first test area (A1). A2 and A3 were built using less LS and coarser fractions of EAFS since laboratory tests had given satisfactory results also for these recipes. High infiltration rates in A2 and 3 led to a return to the original weight proportions in A4 and 5, yet another EAF slag was introduced in these areas. The mixing and construction techniques were refined during the first years of the project time: while A1 was built with rather poorly conceived technique, as of A3 the method can be considered as technically mature and approved.The liner performance was evaluated by lysimetry: 10 lysimeters were installed below each test area. The infiltration below the liner corresponded to 44, 74, 71, 19 and 0.4 l/m2*year for A1 to A5. Compared to the legal limit of 50 l/m2*year, the covers of A2 and A3 allowed about 50 % more water to enter the landfill than stipulated.An initial increase of the infiltration was observed, which most likely is related to increasing water saturation of the liner material in the first period after construction. The saturation occurred fastest in A2, where basically no initial increase was observed, probably due to the long time that elapsed between construction and the first sampling event (260 days). In contrast, the saturation in A1 and A4 was quite slow which can be related to the smaller particle size of the slags in these areas and, hence, a less porous liner material. The decrease in A2 and A3 might be explained by mineral transformations within the slag matrix such as carbonation of calcium and magnesium leading to the precipitation of carbonates in the pores of the liner material. Future observations will show if the decreasing trend in A2 and A3 remains such that the infiltration eventually reaches a level falling below the legal limit.The results show that the infiltration criteria can be fulfilled under the condition that at least 50 % of the liner mix consists of ladle slag, a fine-grained slag with cementitious properties. With few adaptations the steel slag can be used with standard construction processes.

  • 28.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Diener, Silvia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Steel slags in a landfill top cover: Experiences from a full-scale experiment2014In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 34, no 3, p. 692-701Article in journal (Refereed)
    Abstract [en]

    A full scale field study has been carried out in order to test and evaluate the use of slags from high-alloy steel production as the construction materials for a final cover of an old municipal landfill. Five test areas were built using different slag mixtures within the barrier layer (liner). The cover consisted of a foundation layer, a liner with a thickness of 0.7 m, a drainage layer of 0.3 m, a protection layer of 1.5 m and a vegetation layer of 0.25 m. The infiltration varied depending on the cover design used, mainly the liner recipe but also over time and was related to seasons and precipitation intensity. The test areas with liners composed of 50% electric arc furnace (EAF) slag and 50% cementitious ladle slag (LS) on a weight basis and with a proper consistence of the protection layer were found to meet the Swedish infiltration criteria of ⩽50 l (m2 a)−1 for final covers for landfills for non-hazardous waste: the cumulative infiltration rates to date were 44, 19 and 0.4 l (m2 a)−1 for A1, A4 and A5, respectively. Compared to the precipitation, the portion of leachate was always lower after the summer despite high precipitation from June to August. The main reason for this is evapotranspiration but also the fact that the time delay in the leachate formation following a precipitation event has a stronger effect during the shorter summer sampling periods than the long winter periods. Conventional techniques and equipment can be used but close cooperation between all involved partners is crucial in order to achieve the required performance of the cover. This includes planning, method and equipment testing and quality assurance.

  • 29. Andreas, Lale
    et al.
    Ecke, Holger
    Shimaoka, T.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Characterizing landfill phases at full-scale with the aid of test cells1999In: Sardinia 99: proceedings / Seventh International Waste Management and Landfill Symposium, [4 - 8 October 1999, S. Margherita di Pula, Cagliari, Sardinia, Italy]. / [ed] Thomas H. Christensen, Cagliari: CISA, Environmental Sanitary Engineering Centre , 1999, Vol. 1, p. 145-152Conference paper (Refereed)
  • 30.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jannes, Sara
    Telge Återvinning AB.
    Mellström, Anna
    Telge Återvinning AB.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tham, Gustav
    Telge Energi AB.
    Chemical and hydraulic conditions in a landfill/deposit for wood-based ash2004In: The 3rd Intercontinental Landfill Research Symposium November 29th - December 2nd, 2004 in Toya, Hokkaido Japan / [ed] Morton Barlaz; Anders Lagerkvist; Toshihiko Matsuto, Hokkaido: Center for Applied Ethics and Philosophy, Hokkaido University, 2004, p. 121-129Conference paper (Other academic)
  • 31. Andreas, Lale
    et al.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mácsik, Josef
    Ecoloop, Stockholm.
    Tham, Gustav
    Telge AB.
    Use of secondary materials in landfill constructions2007In: SARDINIA 2007: Eleventh International Waste Management and Landfill Symposium ; [1 - 5 October 2007, S. Margherita di Pula, Cagliari, Sardinia, Italy] / [ed] Raffaello Cossu, Cagliari: CISA, Environmental Sanitary Engineering Centre , 2007Conference paper (Refereed)
    Abstract [en]

    Many landfills are subject to closure in the near future. Roughly 2,000 hectares of land­fill area have to be covered only in Sweden, equivalent to about 100 million tonnes of construction material. In addition to material costs in the order of tens of billions Euro, this also puts a strain on the environment through the exploitation of non-renewable virgin construction materials. Many landfill operators are considering alternative cover designs and materials in order to reduce resource spending. However, there is a fair amount of uncertainty with regard to functional and environmental consequences of using alternative (secondary) materials, both from the side of the companies and the authorities. This paper gives an overview over potential waste based construction materials and the use of some of them in projects presently ongoing in Sweden.Research on the use of secondary materials in landfill covers is quite recent. Substitutes for natural or synthetic materials in a landfill cover can be various types of waste from process industry, construction and demolition, or comparable activities. Alter­na­tive mate­rials that have been investigated are ashes, slags, sewage and fibre sludges, treated soils and com­post. Table 1 gives an overview over potential waste based construction materials. The total of potential materials is well in excess of the material needs for landfill construction, but they may not be available at the right time, place or quality.Besides being economically viable, the substitute materials should have suitable technical and environmental properties in order to secure a proper function of the construction. Experiences from three field studies (landfills at Tveta/Södertälje, Hagfors and Alvkarleby) are discussed looking at relevant issues during 1) construction, 2) active after care phase, and 3) long term processes.Using SCM poses additional problems compared to using conventional materials. Often, the supply of material has to be planned in advance and the materials may have to be stored on site. Storing, however, can cause problems if the materials have properties that change over time e.g. due to climate. For other materials storing may be necessary in order to achieve desired properties. One example is the ageing of strongly alkaline materials that react with atmospheric carbon dioxide and thus obtain better leaching properties. Table 1 Overview over potential waste based construction materials and examplesSourceExamplesMining and mineral industryWaste rock, flotation sand, etc...Construction and demolition (C&D)Crushed concrete, gypsum, asphalt, reinforced polymers, woodProcess industryDifferent types of slag from steel making, green liquor and fibre sludge from paper production, ashes and foundry wastesWastewater treatmentDigested sewage sludge, sandIncinerationBottom ash, fly ashThe evidence is mounting that the desired technical function of a landfill cover can be attained using suitable combinations of secondary construction materials. So far, all three field tests indicate leachate amounts between less then one and 30 l (m2 yr)-1 below the liner. In comparison with the average annual precipitation of about 600 mm yr-1 at the Swedish East coast, only 0.2-5 % of the precipitation seeped through the liner so far; i.e. the leachate generation is reduced with about 90 % or more.The issue is more if the materials may cause adverse impacts of the landfill and its recipients. A low water infiltration through the liner means that the most of infiltrating water is removed as drainage water and thus the leaching of the layers above the liner are of the greatest concern.Infiltrating water will yield a liquid to solid ratio of about 1-2 l kg-1 in the layers above the liner after about 10 years. The most mobile elements, such as nitrogen, will be leached to a great extent already at such low L/S ratios, so a forecast with regard to the need of treatment of drainage water points at about two to three decades.In the long term perspective the mineral changes of the construction materials become important. E.g. one of the incentives for using fly ash in liners is their capacity for chemical-mineralogical changes leading to the formation of clay-like structures. This could mean that a liner built of ashes will attain a lower permeability over time. Other mineral changes that can occur in ashes include the trapping of metals in the structure, e g in clay and carbonate phases.Much is still to be learned about the long term processes and the factors that control them. Ongoing studies include the assessment of climatic variables, different material combinations as well as the impact of landfill gases.The following conclusions can be drawn:The use of secondary materials in construction is important due to substantial resource and environmental impacts. An increased use should be beneficial, provided that the problems of using such materials can be managed.In addition to legislative and bureaucratic barriers, there are also practical issues which need to be dealt with in order to pave the way for a wider use of alternative construction materials. In the construction phase more planning is needed due to temporal and geographical limitation of the material availability. Some materials are not ready for immediate use but need to be pre-treated. All of these factors may cause a need for more space and time. A system for quality assurance comparable to that of traditional construction materials is another issue that needs to be resolved. Most likely some kind of legislative pressure is needed for this.In the medium term leaching of pollutants from the construction materials may be the most important issue when using secondary construction materials, which underlines the double standards applied, since traditional construction materials will not be scrutinized in the same manner. Anyhow, the long term interactions between materials and their environment need to be considered and further studies are necessary for secondary construction materials as well as for conventional materials. Existing data indicate both possibilities and problems.In the long term issues of material interactions will remain and the mechanical impact of mineral changes in the secondary construction materials may be added to the list of issues to clarify. Some of the material changes may be beneficial for the function of the construction, e.g. clay formation in liner materials may make them more impervious, but there may also be negative changes caused by deteriorated material properties. The rate and extent of such processes and the factors that enhance or retard them need to be understood better.Secondary construction materials have always been used and some of the "traditional" materials used today were wastes before. There is no reason to believe that this development should not continue.

  • 32.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Marklund, Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hydrotermisk karbonisering: en praktisk avfallsbehandlingsmöjlighet?2017Report (Other (popular science, discussion, etc.))
    Abstract [en]

    Hydrothermal carbonization (HTC) is a treatment where an organic material is subjected to a combination of heat and pressure, for example 200°C and 20 bars. Then nutrients are dissolved and the structure of the material is changed, leading to a stabilization and comminution, and making it easier to separate from the inorganic materials. Previously HTC has been used mostly for fuel production, but in this study the potential for detoxification and separation of wastes is in focus, and what role HTC can play as a waste management method. The purpose is to judge the potential of HTC as a method to increase recycling of nutrients in a circular economy with a simultaneous increased detoxification compared to biological treatment, and less emissions of carbondioxide trough other uses of organic materials than as fuel.

    To achieve these goals a lab experiment was done with subsequent chemical analyses, and the results provided a basis for a multivariate analysis and a life cycle assessment (LCA). The results shows a detoxification trough a separation of the amounts of hazardous heavy metals and that there is an increase in heating value. However, the processed material cannot be used as a soil improver or as a construction material, but this is due to the fact that it was already contaminated.

    HTC is most suitable for wet, organic, mixed wastes. A market analysis shows that 100 000's tons of these wastes are produced every year in Sweden.

    To sum up, the process can be interesting as a waste management method, however more research is needed on the mechanical properties and separation of the material.

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  • 33.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tham, Gustav
    Telge AB.
    Utvärdering av fullskaleanvändning av askor och andra restprodukter vid sluttäckning av Tveta Återvinningsanläggning2008Report (Other academic)
    Abstract [en]

    In 2000 Telge Återvinning - a waste management recycling company - started investigating ashes from incineration of industrial and biowaste waste. The company was given a permit from the Swedish Environmental Court to cover four hectares of the house hold waste landfill area. In 2006 the company received an unlimited permit to cover the remaining part of the landfill when the works end some thirty years later.Ashes were used the first time in 1966 for testing. Literature studies indicated the ashes can have a low hydraulic conductivity under certain conditions. In 1999 collaboration started with the Division of Waste Science and Technology at Luleå University of Technology.Residuals from household and industrial waste were subject to investigation. Initially, biowaste incineration products were subject to testing and were later extended to other waste products, e.g. sludge, contaminated soils, foundry, and compost material. Several different sub-fractions of ashes were included in the investigation e.g. bottom and fly ash, various slag products after up-grading including dewatering, separation and sifting. Subsequently, a complete covering system of a landfill consists of residuals.Six test areas were outlined in order to give a good representation for cover construction in flat and steep areas with different compositions of liner material.The results show that in all areas the hydraulic conductivity construction yields less then 50 liters per square meters and years and can be less the than 5 liters in a repository for hazardous waste if required. In accordance with literature data the field observations show the liner material constructed only by ash material under certain conditions can form a monolithic structure due to very slow processes thus indicating small pore volumes that unable water - air to interact with other media.The concept of using ash can be related to natural analogues of volcanic ashes and has been used in old defence walls and other buildings thousand years back. The last part of the report brings a number of topics for future research and a discussion about problems to with the authorities to use residuals for covering landfills.

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  • 34.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Travar, Igor
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tham, Gustav
    Sweco AB.
    Leaching behaviour of ashes in a landfill cover construction2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 39-Conference paper (Refereed)
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  • 35.
    Andrén, Anna
    et al.
    The Swedish Transport Administration, Borlänge, Sweden.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Degradation of the Reinforcing Effect of Shotcrete: Freeze-Thaw Tests on Shotcrete-Rock Panels2020In: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 25, no 1, p. 1-30Article in journal (Refereed)
    Abstract [en]

    In rock tunnels in regions with colder climates, the load-bearing structure, including the rock and the reinforcing elements, is exposed to repeated destructive freezing and thawing cycles during the winter. If water accumulates in cracks or in the interface between rock and shotcrete, frost shattering may occur. If there is adequate adhesion between the rock and shotcrete, degradation of the shotcrete as a reinforcement element due to frost shattering should not present a problem. However, if adhesion is poor, a small void will form between the rock and the shotcrete where water can accumulate. If the water in these voids is subjected to freeze-thaw cycles, ice will develop, thus exerting pressure on the interface and causing the shotcrete to crack and degrade. In tunnel sections with complex water conditions, for example, relatively water-bearing open joints and weak zones, the adhesion of the shotcrete and its stability and reinforcing effect may be strongly affected when exposed to freezing temperatures. This article describes a laboratory study that comprised freeze-thaw tests on shotcreterock panels with the objective of studying how water migration affects the growth of ice and the ice pressure in the shotcrete-rock interface to better understand the degradation of the reinforcing effect of shotcrete

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  • 36.
    Andrén, Anna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. The Swedish Transport Administration, Borlänge, Sweden.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Evaluation of a laboratory model test using field measurements of frost penetration in railway tunnels2022In: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 204, article id 103660Article in journal (Refereed)
    Abstract [en]

    Despite extensive grouting efforts to prevent water from leaking into tunnels, water seepages remain. When exposed to freezing temperatures, ice formations occur. During the winter, the Swedish Transport Administration's railway tunnels are affected by major problems caused by ice, such as icicles from roof and walls, ice loads on installations, ice-covered tracks and roads, etc. To ensure safety and prevent traffic disruptions, many tunnels require extensive maintenance. Improved knowledge about frost penetration in tunnels is required to reduce maintenance of the tunnels. Frost insulated drain mats are often used at leakage spots to prevent ice formation along the tunnels. To find out which parts of a tunnel are exposed to freezing temperatures, the University of Gävle and the Royal Institute of Technology in Stockholm conducted a laboratory model test on behalf of the Swedish National Rail Administration (now the Swedish Transport Administration). The laboratory model test aimed to find a method to determine the expected temperature conditions along a tunnel to decide which parts of the tunnel require frost insulation to protect the drainage system from freezing and prevent ice formation. To evaluate the laboratory model test, the Swedish Transport Administration in collaboration with Luleå University of Technology have performed field surveys in two Swedish railway tunnels. The field measurements involved monitoring temperatures in air, rock surfaces and rock mass, as well as measuring wind direction, wind and air velocity and air pressure. The measurements in the tunnels show that the frost penetrates further into the tunnels than was expected from the laboratory model test, which was based on a completely uninsulated tunnel. Frost insulated drains do not only prevent the cold air from reaching the rock mass, but also prevent the rock from emitting geothermal heat that warms up the cold tunnel air. Consequently, the frost penetrates further into the tunnel than it would do if the heat from the rock mass was allowed to warm up the outside air on its way into the tunnel. The number of frost insulated drains and how much of the tunnel walls and roof are covered thereby affect the length of the frost penetration.

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  • 37.
    Andrén, Anna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. The Swedish Transport Administration, Borlänge, Sweden.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Field Observations of Water and Ice Problems in Railway Tunnels from a Maintenance Perspective2023In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 13, no 1, p. 11-54Article in journal (Refereed)
    Abstract [en]

    During the winter season, ice causes major problems in many Swedish railway tunnels. Ice, rock and shotcrete in the roof and on the walls may come loose and fall down, installations and cables can break due to ice loads and the tracks can become covered with ice. To maintain safety and prevent traffic disturbances, many tunnels require frequent maintenance. The removal of ice, loose rock and shotcrete is expensive and potentially risky work for the maintenance workers. To reduce maintenance costs, it is important to improve our knowledge of frost penetration inside tunnels and investigate the effect of ice pressure and frost shattering on loadbearing constructions. The aim of this investigation was to gather information about the problems caused by water leakage and its effect on the degradation of a rock tunnel when subjected to freezing temperatures. There are many factors that determine whether frost or ice formations will appear in tunnels. To collect information on ice formation problems, field observations were undertaken in five of Sweden’s railway tunnels between autumn 2004 and summer 2005. For one of the tunnels, follow-up observations also took place in March during the years 2005, 2006 and 2007.

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  • 38.
    Andrén, Anna
    et al.
    The Swedish Transport Administration, Borlänge, Sweden.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Temperature Flows in Railway Tunnels: Field Measurements of Frost Penetration2020In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 10, no 5, p. 161-194Article in journal (Refereed)
    Abstract [en]

    Even though extensive pre-grouting is carried out during the construction of tunnels, certain leakages and drips remain. These remaining leakages are remedied by a combination of post-injection and drainage measures with, for example, frost insulated drain mats, whose function is to prevent the cold tunnel air from reaching a leakage spot and causing water to freeze. Despite these measures, some water may still enter the tunnels and cause problems during winter with ice formations and frost shattering. Icicles, ice pillars and ice-covered roads and railway tracks require constant maintenance. If ice occurs in the fracture network close to the tunnel contour or in the interface between the rock and shotcrete, it can cause degradation of the load-bearing capacity of the tunnel and fall-outs of both materials. In tunnel sections with water leakage problems it is common to protect the load-bearing structure from freezing with insulated drainage systems. To determine where along the tunnel efforts must be made to prevent ice formation, the temperature conditions of tunnels must be investigated. This article presents parts of the results from field measurements in two Swedish railway tunnels. The measurements involves monitoring of air and rock temperatures, air pressure and air velocity.

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  • 39.
    Antelo, Juan
    et al.
    CRETUS-Institute, Cross-disciplinary Research in Environmental Technologies, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
    Fiol, Sarah
    CRETUS-Institute, Cross-disciplinary Research in Environmental Technologies, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain Department of Physical Chemistry, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Department of Earth System Science, School of Earth, Energy, and Environmental Sciences, Stanford University, Stanford, CA 94305, USA.
    Arroyo, Arantxa
    Department of Physical Chemistry, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
    Lezama-Pacheco, Juan S.
    Department of Earth System Science, School of Earth, Energy, and Environmental Sciences, Stanford University, Stanford, CA 94305, USA.
    Josevska, Natasha
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Protopapa, Chloe
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stability of naturally occurring AMD–schwertmannite in the presence of arsenic and reducing agents2021In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 220, article id 106677Article in journal (Refereed)
    Abstract [en]

    Secondary iron oxides formed in acid mine drainage, such as schwertmannite, are scavengers for metal(loid)s in mining environments. Increasing the understanding of the geochemical transformations of these minerals, as well as knowing how metal(loid)s affect these transformations, is crucial to ultimately predict the fate of these trace elements in acidic mine drainage and to minimize the potential environmental risk. In this study, transformation experiments have been conducted with a schwertmannite-rich sediment collected from a mining area and with synthesized schwertmannite as a reference material. The transformation of schwertmannite into goethite was studied as a function of the presence of arsenic, pH value, and redox conditions. Arsenic delayed the mineral transformation from pseudo-stable amorphous phases to more stable crystalline forms, especially at higher arsenic loadings and more acidic pH. Experiments in the presence of Fe(II) and ascorbic acid have proven that both components promote the mineral transformation or reductive dissolution of schwertmannite under anoxic conditions. The presence of arsenic reduced the catalytic effect of Fe(II), stabilizing the schwertmannite particles. On the other hand, arsenic had no effect on the reductive dissolution at these conditions when ascorbic acid was used as a reducing agent. © 2020 Elsevier B.V.

  • 40.
    Arm, Maria
    et al.
    Swedish Geotechnical Institute (SGI), Department of Environmental Engineering, Olaus Magnus väg 35, SE-581 93 Linköping, Sweden.
    Vestin, Jenny
    Swedish Geotechnical Institute (SGI), Universitetsallén 32, SE-851 71 Sundsvall, Sweden.
    Lind, Bo B.
    Swedish Geotechnical Institute (SGI), Hugo Grauers gata 5B, SE-412 96 Göteborg, Sweden.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordmark, Desirée
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hallgren, Per
    Swedish Forest Agency, Hovrättsgatan 3, Box 284, SE-90 106 Umeå, Sweden.
    Pulp mill fly ash for stabilization of low-volume unpaved forest roads — field performance2014In: Canadian journal of civil engineering (Print), ISSN 0315-1468, E-ISSN 1208-6029, Vol. 41, no 11, p. 955-963Article in journal (Refereed)
    Abstract [en]

    Increased temperatures and rainfalls will give more settlements and less bearing capacity in gravel roads, which will have implications for the forestry. Pulp mill fly ash without additives was used for stabilizing the road base of a low-volume gravel road. A two-year monitoring of the road was conducted, including measurements of achieved ash content, density, water infiltration capacity, and load bearing capacity. The results showed that the ash-stabilized sections performed better than conventionally upgraded sections and also achieved increased bearing capacity over time. Hydration of the fly ash increased the stiffness and decreased the permeability of the road base. The differences were more pronounced during spring thaw. Best performance was achieved in the section with thicker ash stabilized layer.

  • 41.
    Arredondo, Cesar
    et al.
    University of Chile.
    Montes Atenas, Gonzalo
    University of Chile.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Casali, Aldo
    University of Chile.
    Valencia, Alvaro
    University of Chile.
    Firsching, Markus
    Fraunhofer Development Centre X-ray Technology EZRT, Fürth, Germany.
    Valenzuela, Fernando
    University of Chile.
    Insights on the application and evaluation of ore sorting technologies in mining operations: A critical review2021In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444Article in journal (Refereed)
  • 42. Arvanitidis, Ioannis
    et al.
    Nyberg, Ulf
    Ouchterlony, Finn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Diameterns inverkan på detonationsegenskaperna hos emulsionssprängämne E682 i cylinderprovet2004Report (Other academic)
    Abstract [en]

    Cylinder expansions tests with 4 different diameters ranging from 40 to 100 mm have been conducted on the generic emulsion explosive E682, both pure and with 20 % ANFO content. The work capacity is expressed in terms of the Gurney energy EG, which equals the sum of the kinetic energy of the copper tube and the radial kinetic energy of the gases. The purpose was to study the effect of charge diameter on the explosive's work capacity expressed as the Gurney energy and to supplement earlier work done by Nie (2001). The radial expansion has been measured as well as the velocity of detonation in 11 copper tubes. The effect of ANFO granules were tested by making a mixture of E682 with 20% ANFO. The ANFO used in the present study is Anolit from Dyno Nobel, which basically is the same product as the Prillit A used by Nie. The average density of pure E682 was 1130 kg/m3 and that of E682 with 20% ANFO 1200 kg/m3. The results from the new batch of E682 show similarities with the old batch regarding VOD as function of inverse charge diameter but the trend of the Gurney energy is different from the first experiments carried out by Nie. This could be due to previous tolerance variations in the tube dimensions. The Gurney energy seems to be independent of the charge diameter between 40-100 mm in the new experiments. The measured Gurney energy for pure E682 was 1.77 ± 0.06 MJ/kg and that of E682 with 20% ANFO 1.71 ± 0.07 MJ/kg which is somewhat lower. The use of 20% ANFO in E682 results in the same volume based Gurney energy as for pure E682 however. The overall average is 2.02 ± 0.02 MJ/dm3. The energy utilisation ratio is 0.58 ± 0.03 for pure E682 and 0.53 ± 0.03 for E682 with 20% ANFO. This is slightly lower than for the Titan 6000 series gassed bulk emulsion but higher than for pure ANFO. The detonation pressure decreases with the charge diameter however and this indicates that a smaller hole diameter in rock blasting leads to a lower detonation pressure without loosing work energy when keeping the powder factor constant.

  • 43.
    Ascher, J.
    et al.
    University of Florence.
    Ceccherini, M.T.
    University of Florence.
    Guerri, G.
    University of Florence.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Landi, L.
    University of Florence.
    Mench, Michel
    Bordeaux 1 University.
    Nannipieri, P.
    University of Florence.
    Pietramellara, G.
    University of Florence.
    Renella, Giancarlo
    University of Florence.
    Is microbial species richness increased by aided phytostabilization of trace element contaminated soils?2008Conference paper (Other academic)
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  • 44.
    Asghari, M.
    et al.
    University of Tehran, Tehran, Iran.
    Noaparast, M.
    University of Tehran, Tehran, Iran.
    Shafaie, S. Z.
    University of Tehran, Tehran, Iran.
    Ghassa, S.
    University of Tehran, Tehran, Iran.
    Chelgani, Saeed Chehreh
    University of Michigan, Ann Arbor, USA.
    Recovery of coal particles from a tailing dam for environmental protection and economical beneficiations2018In: International Journal of Coal Science & Technology, ISSN 2095-8293Article in journal (Refereed)
    Abstract [en]

    Considerable amounts of coal particles are accumulated in the tailing dams of washing plants which can make serious environmental problems. Recovery of these particles from tailings has economically and environmentally several advantages. Maintaining natural resources and reducing discharges to the dams are the most important ones. This study was examined the possibility to recover coal particles from a tailing dam with 56.29% ash content by using series of processing techniques. For this purpose, gravity separation (jig, shaking table and spiral) and flotation tests were conducted to upgrade products. Based the optimum value of these processing methods, a flowsheet was designed to increase the rate of recovery for a wide range of coal particles. Results indicated that the designed circuit can recover over 90% of value coal particles and reduce ash content of product to less than 14%. These results can potentially be used for designing an industrial operation as a recycling plant and an appropriate instance for other areas to reduce the environmental issues of coal tailing dams.

  • 45.
    Asimi Neisiani, A.
    et al.
    Department of Mining and Metallurgical Engineering Yazd University, Yazd 89195-741, Iran.
    Saneie, R.
    Department of Materials Engineering, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
    Mohammadzadeh, A.
    School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    Wonyen, D. G.
    Department of Material Science and Engineering (Mining and Mineral Processing Engineering), African University of Science and Technology Abuja, Nigeria.
    Chelgani, Saeed Chehreh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Biodegradable hematite depressants for green flotation separation – An overview2023In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 199, article id 108114Article, review/survey (Refereed)
    Abstract [en]

    Due to environmental issues and the restrictions imposed on mineral flotation separation, the use of biodegradable and environmentally friendly reagents has gained widespread international attention. So far, several investigations have been conducted regarding the eco-friendly flotation separation of iron oxide ores for moving toward sustainable development and cleaner production. Yet, no critical review is specified on the green and eco-friendly depression reagents through their reverse flotation beneficiation. Therefore, this study will comprehensively discuss the previously conducted works in this area and provides suggestions for future assessments and developments. This robust study explored various adsorption aspects of natural-based depressants (polysaccharide-, polyphenolic-, and lignosulfonate-based) on iron oxide minerals (mainly hematite) to create a possible universal trend for each biodegradable depressant derivative. The laboratory and industrial experiments indicated that these depressants (except lignosulfonate-based) could selectively depress hematite at alkaline pHs and enhance its reverse flotation separation from their gangue phases (especially silicates as the main gangue phases). Although these eco-friendly depressants showed promising metallurgical results, several gaps still need to be addressed, notably in surface analyses and their adsorption mechanisms.

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  • 46.
    Asimi Neisiani, Ali
    et al.
    Department of Mining and Metallurgical Engineering, Yazd University, Yazd, Iran.
    Chehreh Chelgani, Saeed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Biodegradable acids for pyrite depression and green flotation separation–an overview2023In: Critical reviews in biotechnology, ISSN 0738-8551, E-ISSN 1549-7801Article, review/survey (Refereed)
    Abstract [en]

    Exponential increasing demands for base metals have made meaningful processing of their quite low-grade (>1%) resources. Froth flotation is the most important physicochemical pretreatment technique for processing low-grade sulfide ores. In other words, flotation separation can effectively upgrade finely liberated base metal sulfides based on their surface properties. Various sulfide surface characters can be modified by flotation surfactants (collectors, activators, depressants, pH regulators, frothers, etc.). However, these reagents are mostly toxic. Therefore, using biodegradable flotation reagents would be essential for a green transition of ore treatment plants, while flotation circuits deal with massive volumes of water and materials. Pyrite, the most abundant sulfide mineral, is frequently associated with valuable minerals as a troublesome gangue. It causes severe technical and environmental difficulties. Thus, pyrite should be removed early in the beneficiation process to minimize its problematic issues. Recently, conventional inorganic pyrite depressants (such as cyanide, lime, and sulfur-oxy compounds) have been successfully assisted or even replaced with eco-friendly and green reagents (including polysaccharide-based substances and biodegradable acids). Yet, no comprehensive review is specified on the biodegradable acid depression reagents (such as tannic, lactic, humic acids, etc.) for pyrite removal through flotation separation. This study has comprehensively reviewed the previously conducted investigations in this area and provides suggestions for future assessments and developments. This robust review has systematically explored depression performance, various adsorption mechanisms, and aspects of these reagents on pyrite surfaces. Furthermore, factors affecting their efficiency were analyzed, and gaps within each area were highlighted.

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  • 47.
    Asplund, Erik
    et al.
    inno Scandinavia AB.
    Lagerkvist, Anders
    Heydebreck, Peter
    inno AG.
    Dahlén, Lisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Norberg, Anna
    Umeå universitet.
    Framsyn för Norrbotten och Västerbotten: en idéskrift om utvecklingsinsatser idag och imorgon2009Report (Other academic)
    Abstract [sv]

    Rapport från DARE delprojekt regional framsyn. Etapp 1; scenarier och förslag på aktiviteter.Detta dokument är slutrapporten från den regionala framsynsprocessen som drevs 2008-2009 inom projektet DARE – Development Arena for Research and Entrepreneurship.Framsynen har verkat efter ett normativt och handlingsinriktat angreppssätt. Ledmotiv för processen har varit frågor som: Hur vill vi ha det? Varför är det inte så nu? Vad behöver vi göra nu och i framtiden? Regionen kan sägas kännetecknas av att den är rik på naturresurser och fattig på folk. Det är bakgrunden till de fokusområden som framsynen behandlat- Grönare näringsliv (hur kan nya och miljöeffektivare produkter och tjänsterutvecklas effektivare?)- Demografiutveckling (hur kan samhällsfunktionerna bestå med inverteradebefolkningspyramider och hur kan utvecklingen mot en åldrande befolkningvändas?)Lite tvärs över båda frågorna ovan hamnar ett annat fokus; regionens attraktivitet. Inom detta område har en ung framsyn genomförts med deltagare från olika delar av Norrbotten.Framsynen har gått steg för steg genom visioner, analys av framgångsfaktorer, scenarieskapande, förslag på åtgärder och prioritering av dessa. Under genomförandet har det uppstått ett antal avknoppningar i form av t ex nya samarbeten och projekt. Ett av de sistnämnda var den unga framsynen som genomfördes med finansiering av Norrbottens läns landsting.Bland de prioriterade förslagen som redovisas i denna rapport dominerar olika aktiviteter för att knyta samman olika aktörer och grupper inom regionen och på så sätt göra mer av mindre. Många av förslagen visar regionala aktörers förväntningar på universitetens roll i den regionala utvecklingen och markerar ett intresse av tätare samverkan meduniversiteten. Förslagen berör alla verksamheter inom universiteten, såväl utbildning, forskning och förvaltning. Bland de prioriterade förslagen finns:• Stimulera gröna affärs och teknikutvecklingsallianser för regionens småföretag• Stimulera ”den lille forskaren” – en modell för småföretagens forskarkollektiv• Utred grönare näringsliv som gemensamt profilområde för regionens universitet• Stärk företagsnyttig forskning & utvecklingsinsatser kring ”age management”• Etablera ett ”integrationsnätverk” för universitetens studenter & det regionalasamhället• Utveckla dialogen mellan universiteten & avnämargrupper i utvecklingen avutbildningar • Skapa regionalt utvecklingslab för bättre samverkan mellan universiteten ochomgivande samhälleInom DARE-projektet kommer nu det material som utvecklats inom framsynsprocessen att användas för utveckling av samverkan inom universiteten, mellan universiteten och med andra intressenter av den regionala utvecklingen, inte minst då de som deltagit i framsynen.

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  • 48.
    Ataide Salvador, Dandara
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Geometallurgical Variability Study of Spodumene Pegmatite Ores, Central Ostrobothnia - Finland2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This geometallurgical variability study was conducted for Keliber Oy definitive feasibility study. It includes the Syväjärvi, Länttä and Rapasaari lithium ore deposits located in Central Ostrobothnia – Finland. These deposits present different characteristics in terms of spodumene grade, grain size, alteration, and weathering.

    A geometallurgical approach was used to characterize the ore and learn about the variability within and between the deposits in terms of mineralogy and processing response. In the project design chosen, grinding and flotation tests were performed. In addition, chemical composition of spodumene, mineralogical and liberation studies were carried out by MLA and EDS analysis.

    Spodumene is the main Li mineral in the deposits and its characteristics and elemental composition differ between and within these deposits, affecting mineral processing behavior. Spodumene impurities content as FeO and MnO are the highest in Länttä and lowest in Rapasaari. With respect to the harmful elements, Mg is carried by amphiboles and micas and P by apatite and sicklerite.

    Grinding is mainly influenced by the spodumene grade of the ore. The total grinding time to reach the P80 target was similar for the average ores, around 30 minutes of two stage grinding. Pre-flotation removed more than 50% of the apatite with on average 4.6% losses of spodumene. A cleaning stage for the pre-flotation product is recommended to recover some of the spodumene losses.

    In spodumene flotation with rougher and seven cleaning stages, Syväjärvi average ore showed high recoveries (about 90%) to final concentrate, whereas Länttä and Rapasaari presented clearly lower recoveries, (about 70%). In addition, Länttä presented the lowest spodumene grade in the final concentrate (about 70%) and Rapasaari the highest (about 75%). The flotation process, in general, turned out to be efficient in terms of concentrate grade, achieving, in most of the cases, the targeted Li2O grade of 4.5%. Although, the geometallurgical test is based on flowsheet developed for Syväjärvi and it is quite expected that Länttä and Rapasaari samples show poorer performance. Therefore, flotation tests and process optimization should be done to improve the spodumene recovery of Länttä and Rapasaari deposits. Considering Syväjärvi samples, spodumene head grade and grain size had positive effects in flotation. In contrast, spodumene alteration had a negative effect. Länttä shows lower spodumene liberation with given grind which leads to lower recovery and grade in flotation. A combination of lower feed grade, locking association, P80 and secondary Li minerals may explain Rapasaari samples performance. The weathered Rapasaari sample showed a positive effect on spodumene recovery which is possibly due to the liberation of spodumene grains from feldspars and quartz. Controlled waste dilution on ore samples promoted lower spodumene recovery and lower final concentrate grades, proportional to the dilution ratio. The results indicate that flowsheet and processing conditions as P80 and collector dosage need to be optimized by the deposit and by the ore type. Nevertheless, the present study is a diagnostic test and the results cannot be directly correlated to full-scale process.

  • 49.
    Atta, Khalid Tourkey
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Euzébio, Thiago
    Instituto Tecnológico Vale.
    Ibarra, Haroldo
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Silva Moreira, Vinicius
    Vale S.A..
    Johansson, Andreas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Extension, Validation, and Simulation of a Cone Crusher Model2019In: 18th IFAC Symposium on Control, Optimization and Automation in Mining, Mineral and Metal Processing, MMM 2019: Stellenbosch, South Africa, 28–30 August 2019 / [ed] Lidia Auret, Elsevier, 2019, p. 1-6Conference paper (Refereed)
    Abstract [en]

    This work presents an extension and validation for a control oriented model of cone crushers. Compared to earlier work, the aspect of energy consumption was added to the model. Validation was carried out using measurement data from two different crusher models and was based both on laboratory data and field experiment data. Using the results from the field trials, a plant simulator for a secondary crushing circuit has been implemented.

  • 50.
    Aulestia, Shane
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Luleå University of Technology, Sweden.
    Wiklund, Viktor
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Luleå University of Technology, Sweden.
    Dossey, Michelle
    Luleå University of Technology, Sweden.
    Knutsson, Roger
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Luleå University of Technology, Sweden.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Luleå University of Technology, Sweden.
    Effect of increased vertical stress on the state of grains in tailingsManuscript (preprint) (Other academic)
    Abstract [en]

    The mining industry has experienced rapid growth, leading to the accumulation of substantial mine waste, commonly referred to as tailings. Tailings are typically stored in tailings storage facilities, conventionally consisting of an impoundment surrounded by tailings dams. The construction of tailings dams can involve various methods, with the upstream method being commonly used in the industry. It is crucial to comprehend the long-term mechanical and geochemical behavior of deposited tailings to ensure the safety of upstream constructed tailings dams. The mineral composition, particle size distribution, and particle shape all affect the susceptibility to particle breakage or physical alternation. Therefore, there is an interest in understanding how grain size and grain shape relate to mineral composition and potential particle breakage to ensure the understanding of the long-term mechanical behavior. This study focuses on characterizing deposited tailings from various depths and investigates the impact of increased vertical stress on tailings, particularly examining the potential for crushing effects. The findings highlight the importance of considering these factors for a comprehensive understanding of tailings behavior and their implications for the long-term safety of tailings dams.

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