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  • Fredriksson, Julia
    et al.
    Luleå University of Technology, Department of Health Sciences, Nursing Care. Luleå University of Technology, Department of Health Sciences, Nursing and Medical technology.
    Grundström, Linn
    Luleå University of Technology, Department of Health Sciences, Nursing Care. Luleå University of Technology, Department of Health Sciences, Nursing and Medical technology.
    Patienters upplevelser av att vårdas på akutmottagningen: En litteraturstudie2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Att drabbas av akut sjukdom är fysiskt och psykiskt påfrestande för den enskilda individen. Akutmottagningen är ofta den första kontakten patienten har med vården. Många människor som besöker akutmottagningen är svårt sjuka eller skadade. Syftet med litteraturstudien var att beskriva patienters upplevelser av att vårdas på akutmottagningen. Aktuell forskning söktes fram i två databaser. Elva artiklar kvalitetsgranskades med hjälp av SBU:s granskningsmall och bedömdes hålla medel till hög kvalitet. En kvalitativ innehållsanalys med manifest ansats utfördes. Detta resulterade i fyra kategorier; “Att kommunikation och tillräcklig information är värdefullt”, “Att vara tvungen att vänta länge”, “Att inte känna sig sedd och tagen på allvar”och ”Att känna sig sedd och lyssnad på. Resultatet visade hur betydelsefullt information och kommunikation var för vårdupplevelsen på akutmottagningen. Många patienter delade upplevelsen av att väntan var en stor del i att vårdas på akutmottagningen. Sjuksköterskan behöver beakta det humanistiska perspektivet och se till människan som en helhet för att kunna skapa sig förståelse ur ett patientperspektiv.

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  • Hermansson, Agnes
    et al.
    Luleå University of Technology, Department of Health Sciences, Nursing and Medical technology.
    Skaf, Elena
    Luleå University of Technology, Department of Health Sciences, Nursing and Medical technology.
    Återintegrering efter obstetrisk fisteloperation: En integrerad litteraturöversikt2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Obstetrisk fistel beskrivs som en abnormal gång mellan vaginan och urinblåsan och/eller rektum, där urin och/eller avföring läcker ut okontrollerat. Den vanligaste orsaken till utvecklandet av obstetrisk fistel är en dystoki. Att drabbas av obstetrisk fistel innebär en stor risk att bli stigmatiserad samt att det är ett tillstånd som är förödande för kvinnors välbefinnande, mentala hälsa och liv. För att en kvinna ska kunna återgå till det liv hon levde innan utvecklandet av obstetrisk fistel så krävs en återintegrering. Syftet med studien var att beskriva faktorer som påverkar kvinnors återintegrering efter korrektiv operation för obstetrisk fistel. Denna studie har utgått ifrån en integrerad metodartikel med en induktiv ansats, där studien har utgått ifrån syftet utan något teoretiskt ramverk. Analysen resulterade i fyra kategorier, hälsa, stöd, ekonomi och kunskap. Resultatet visade att en lyckad korrektiv operation underlättade kvinnors återintegrering tillsammans med stöd från familj och samhälle. Dock fanns det en stor risk för kvinnor utan stöd att ha fortsatta och djupare depressioner. Kvinnorna kunde inte åstadkomma en lyckad återintegrering om de inte fick tid och stöd för att återhämta sig. Detta gällde också ekonomiskt stöd. Denna litteraturöversikt kan tillföra en ökad förståelse till sjukvårdspersonal som arbetar med denna patientgrupp, för hur obstetrisk fistel påverkar kvinnor samt vilka faktorer som påverkar kvinnors återintegrering.

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  • Johansson, Emma
    et al.
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Forsberg, Linn
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Faktorer i sjuksköterskans organisatoriska och sociala arbetsmiljö som påverkar patientsäkerheten: En systematisk litteraturöversikt2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund: Patientsäkerhet är en viktig del inom hälso- och sjukvården eftersom att patientsäkerhet har en avgörande betydelse för vårdens kvalité. En hög patientsäkerhet är en förutsättning för att kunna ge en god och säker vård. Patientsäkerhet är ett ständigt aktuellt ämne som berör många, både hälso- och sjukvårdspersonal, patienter men även samhället. Att arbeta patientsäkert och följa evidensbaserad kunskap är viktigt för att kunna förhindra riskfyllda situationer där vårdskador kan inträffa. Syfte: Syftet med denna studie var att sammanställa kunskap om vilka faktorer i sjuksköterskans organisatoriska och sociala arbetsmiljö som påverkar patientsäkerheten. Metod: Studien genomfördes och utformades som en systematisk litteraturöversikt med utgångspunkt från två frågeställningar: Vilka faktorer i den organisatoriska arbetsmiljön påverkar patientsäkerheten? samt vilka faktorer i den sociala arbetsmiljön påverkar patientsäkerheten? Fjorton vetenskapliga artiklar, med både kvantitativ och kvalitativ ansats analyserades. Resultat: Flera faktorer i sjuksköterskans organisatoriska och sociala arbetsmiljö kunde påverka patientsäkerheten. Faktorer i den organisatoriska arbetsmiljön var bemanning, arbetsbelastning, kompetens, arbetslivserfarenhet, återhämtning och trötthet. Faktorer i den sociala arbetsmiljön var samarbete, kommunikation och säkerhetskultur. Slutsats: Det fanns ett samband mellan patientsäkerhet och sjuksköterskans arbetsmiljö. Åtgärder bör vidtas i den organisatoriska och sociala arbetsmiljön. Det kan handla om att sjukvårdsledningen och chefer uppmärksammar brister i arbetsmiljön och vidtar relevanta åtgärder för att förbättra patientsäkerheten och uppkomsten av vårdskador. Det kan även handla om att sjuksköterskorna synliggör brister i arbetsmiljön som kan påverka patientsäkerheten negativt. Det är även viktigt att belysa de aspekter i arbetsmiljön som påverkar patientsäkerheten positivt för att kunna utveckla patientsäkerhetsarbetet.

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  • Larsson Hammarlund, Andreas
    et al.
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Lappalainen Rollert, Oliwer
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    “När du är märkt med epilepsi, stängs alla dörrar”: En litteraturstudie om upplevelsen av att leva med epilepsi2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Epilepsi är en kronisk neurologisk sjukdom som förekommer över hela världen. Epilepsi yttrar sig genom olika former av anfall som kan innebära kramper, medvetslöshet, muskelryckningar, utöver det är sjukdomen många gånger helt osynlig. Epilepsi påverkar det dagliga livet för den drabbade, närstående blir också påverkade av denna sjukdom. Syftet med denna litteraturstudie var att beskriva upplevelser av att leva med epilepsi. I litteraturstudien analyserades fjorton vetenskapliga studier med en kvalitativ innehållsanalys. Beskrivningen av upplevelserna av att leva med epilepsi formulerades i sex kategorier. I litteraturstudien framkom det att personer kände sig rädda och oroliga för att få ett anfall eller diagnosen, de upplevde även begränsningar och restriktioner, de kände sig märkta och behandlade annorlunda. Personerna upplevde sig även som en börda då dem hade ett behov av stöd från sin omgivning, och upplevde en förändrad vardag på grund av sjukdomen. Till slut lärde sig personerna att acceptera sin sjukdom. Genom en ökad kunskap och djupare förståelse för upplevelser av sjukdomen kan sjuksköterskan bättre anpassa omvårdnadsåtgärder och på så vis ge en patientcentrerad omvårdnad för att främja både livskvalitet och hälsa hos denna patientgrupp.

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  • Larsson, Lisette
    Luleå University of Technology, Department of Arts, Communication and Education.
    Datorspel i undervisningen: En analys av hur intrigen i The Witcher 2: Assassins of kings kan användas i svenskundervisningen2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Analysens syfte var att presentera om ett datorspel kan betraktas som en berättande text, hur ett datorspel skiljer sig från andra berättande texter, samt hur datorspelet The Witcher 2: Assassins of kings (2011) kan användas som en berättande text i gymnasieämnet svenska. Analysarbetet genomfördes genom att spela datorspelet, skriva loggbok och spela in spel-tillfällena. För att klargöra om datorspelet kan betraktas som en berättande text använde jag mig av forskning som definierar en berättande text. Sedan jämförde jag datorspelets berättelse mot forsknings-resultaten. Gällande användningen i gymnasieämnet svenska reflekterade jag över Skol-verkets formuleringar i det centrala innehållet för kurserna. Resultatet som jag kunde utläsa var att datorspel kan betraktas som berättande text och är möjliga att använda i gymnasieämnet svenska. Beträffande skillnaderna från andra berättande texter är ett The Witcher 2 ett icke-linjärt datorspel med interaktiva inslag, vilket innebär att berättelsen kräver större engagemang från en spelare i jämförelse med en läsare.

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  • Lundberg, Carolin
    Luleå University of Technology, Department of Arts, Communication and Education.
    Lärplattan i förskolan: En kvalitativ studie om lärplattans roll i förskolan2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna kvalitativa studie är att beskriva såväl användningen av lärplattan i förskolan som användningens betydelse för interaktion, delaktighet och lärande i förskoleverksamheten. Vidare kommer de pedagogiska möjligheter och utmaningar som följer med lärplattans användning i förskolan att diskuteras. Studien genomfördes med hjälp av en kvalitativ metod, där intervjuer och videoobservationer gjordes på två olika avdelningar på en förskola. Resultatet i studien visar på att det finns flera olika sätt att arbeta med lärplattan i förskolan. Resultatet ger också exempel på hur interaktionen mellan lärplattan, barnen och förskollärararen kan se ut. Förskollärarna i studien lyfter att lärplattan går att använda som verktyg till exempelvis dokumentation eller till att stötta barnens språkutveckling.

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  • Patel, Alok
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Matsakas, Leonidas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Assessment of Fatty Acids Profile and Omega-3 Polyunsaturated Fatty Acid Production by the Oleaginous Marine Thraustochytrid Aurantiochytrium sp. T66 Cultivated on Volatile Fatty Acids2020In: Biomolecules, E-ISSN 2218-273X, Vol. 10, no 5, article id 694Article in journal (Refereed)
    Abstract [en]

    Thraustochytrids are considered natural producers of omega-3 fatty acids as they can synthesize up to 70% docosahexaenoic acids (DHA) of total lipids. However, commercial and sustainable production of microbial DHA is limited by elevated cost of carbon substrates for thraustochytrids cultivation. This problem can be addressed by utilizing low-cost renewable substrates. In the present study, growth, lipid accumulation and fatty acid profiles of the marine thraustochytrid Aurantiochytrium sp. T66 (ATCC-PRA-276) cultivated on volatile fatty acids (C1, formic acid; C2, acetic acid; C3, propionic acid; C4, butyric acid; C5, valeric acid and C6, caproic acid) and glucose as control were evaluated for the first time. This strain showed an inability to utilize C3, C5 and C6 as a substrate when provided at >2 g/L, while efficiently utilizing C2 and C4 up to 40 g/L. The highest cell dry weight (12.35 g/L) and total lipid concentration (6.59 g/L) were attained when this strain was cultivated on 40 g/L of butyric acid, followed by cultivation on glucose (11.87 g/L and 5.34 g/L, respectively) and acetic acid (8.70 g/L and 3.43 g/L, respectively). With 40 g/L butyric acid, the maximum docosahexaenoic acid content was 2.81 g/L, corresponding to 42.63% w/w of total lipids and a yield of 0.23 g/gcell dry weight (CDW). This marine oleaginous microorganism showed an elevated potential for polyunsaturated fatty acids production at higher acetic and butyric acid concentrations than previously reported. Moreover, fluorescence microscopy revealed that growth on butyric acid caused cell size to increase to 45 µm, one of the largest values reported for oleaginous microorganisms, as well as the presence of numerous tiny lipid droplets.

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  • Patel, Alok
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Matsakas, Leonidas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Sartaj, Km
    Molecular Microbiology Laboratory, Biotechnology Department, Indian Institute of Technology (IIT-R), Roorkee, India.
    Chandra, Rajesh
    Bioenergy Research Laboratory, Department of Polymer & Process Engineering, Indian Institute of Technology Roorkee (Saharanpur Campus), Saharanpur, India.
    Extraction of lipids from algae using supercritical carbon dioxide2020In: Green Sustainable Process for Chemical and Environmental Engineering and Science: Supercritical Carbon Dioxide as Green Solvent / [ed] Inamuddin, Abdullah M. Asiri, and Arun M. Isloor, Elsevier, 2020, p. 17-39Chapter in book (Other academic)
    Abstract [en]

    Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods.

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  • Hammarberg, Samuel
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Kajberg, Jörgen
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Larsson, Simon
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Jonsén, Pär
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Ultra high strength steel sandwich for lightweight applications2020In: SN Applied Sciences, E-ISSN 2523-3971, Vol. 2, no 6, article id 1040Article in journal (Refereed)
    Abstract [en]

    Methods for reducing weight of structural elements are important for a sustainable society. Over the recent years ultra high strength steel (UHSS) has been a successful material for designing light and strong components. Sandwich panels are interesting structural components to further explore areas where the benefits of UHSS can be utilized. The specific properties of sandwich panels make them suitable for stiffness applications and various cores have been studied extensively. In the present work, bidirectionally corrugated UHSS cores are studied experimentally and numerically. A UHSS core is manufactured by cold rolling and bonded to the skins by welding. Stiffness is evaluated experimentally in three-point bending. The tests are virtually reproduced using the finite element method. Precise discretization of the core requires large amounts of computational power, prolonging lead times for sandwich component development, which in the present work is addressed by homogenization, using an equivalent material formulation. Input data for the equivalent models is obtained by characterizing representative volume elements of the periodic cores under periodic boundary conditions. The homogenized panel reduces the number of finite elements and thus the computational time while maintaining accuracy. Numerical results are validated and agree well with experimental testing. Important findings from experimental and simulation results show that the suggested panels provide superior specific bending stiffness as compared to solid panels. This work shows that lightweight UHSS sandwiches with excellent stiffness properties can be manufactured and modeled efficiently. The concept of manufacturing a UHSS sandwich panel expands the usability of UHSS to new areas.

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  • Bauer, Torben
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andreas, Lale
    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.
    Ekman Burgman, Linus
    Technology and Social Change, Linköping University, Sweden.
    Effects of the Different Implementation of Legislation Relating to Sewage Sludge Disposal in the EU2020In: Detritus, ISSN 2611-4135Article, review/survey (Refereed)
    Abstract [en]

    The European Directive 86/278/EEC implemented in 1986 was a means adopted by the European Union to improve use of the valuables in sewage sludge by applying treated sludge on agricultural soils. To prevent an accumulation of pollutants, the Directive provided suggestions limiting concentrations of toxic elements in sewage sludge and agricultural soil. The Directive was implemented diversely throughout EU member states, with current national legislations only partly reflecting the initial intentions of the EU Directive from 30 years ago. This study demonstrates how the European Directive was implemented in three countries currently at different stages of replacing the agricultural application of sewage sludge with incineration (Netherlands, Germany and Sweden). Additionally, recent changes in the legislation with regards to the re-use and final disposal of sewage sludge in the three chosen member states are analysed. The aim was to investigate how each member state has solved the conflict between improvement of nutrient recovery from sludge and limitation of pollutants in agricultural soil. Based on this review, limit values are not necessarily reflected in application rates of sewage sludge in agriculture. Following changes in current legislation, phosphorus recovery will become a priority task. The recovery of other valuables from sewage sludge is currently not regulated in the legislation of the three member states investigated.

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  • Idris, M. A.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordlund, E.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Probabilistic-Based Stope Design Methodology for Complex Ore Body with Rock Mass Property Variability2019In: Journal of mining science, ISSN 1062-7391, E-ISSN 1573-8736, Vol. 55, no 5, p. 743-750Article in journal (Refereed)
    Abstract [en]

    This paper presents a probabilistic approach for optimizing stope design methodology whiletaking into consideration the variability in the rock mass properties. For this study, a complex orebody in aCanadian mine was used. Because of the variability in the rock mass properties of the orebody, it was notpossible to determine precisely, the values of geotechnical design input parameters and hence the need toutilize a probabilistic approach. Point Estimate Method (PEM), a probabilistic tool, was incorporated intonumerical analysis using FLAC3D to study the deformation magnitudes of various stope geometries todetermine the optimal stope geometry with a minimum ground control problem. Results obtained for thedistribution of the wall deformations and the floor heaves for each option of the stope geometry werecompared to select the best geometry to achieve the optimum stability condition. The methodologypresented in this study can be helpful in the process of underground mine planning and optimization incomplex orebody.

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  • Sissakian, Varoujan K.
    et al.
    University of Kurdistan, Erbil, KRG, Iraq. Private Consultant Geologist, Erbil, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Abdullah, Lanja H.
    University of Sulaimani, Sulaimani, KRG, Iraq.
    Neotectonic Activity Using Geomorphological Features in the Iraqi Kurdistan Region2020In: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529Article in journal (Refereed)
    Abstract [en]

    Iraqi Kurdistan Region is located in the northeastern part of the Arabian Plate which is colliding with the Eurasian (Iranian) Plate and is located within the Zagros Foreland Basin. This collision, which is still active with convergent type of tectonic boundary, has caused deformation of the rocks in the Zagros Foreland Basin with different intensities. The deformation intensity decreases southwest wards since the exerted stresses from the collision is in a NE–SW direction. Depending on the deformation intensity and many other factors, the tectonic framework of the region which is part of the main tectonic frame of Iraq is divided into three main tectonic units among them only two units are within Kurdistan Region. The two zones are from NE–SW direction: (1) Shalair Terrane, and (2) Outer Platform. In the current study, evidences about Neotectonic activities are presented from different parts of Kurdistan Region depending on different geomorphological and structural features. Among those features are: abnormal trends of valleys, dislocated and dissected alluvial fans, regional lineaments, water and wind gaps, faulted rocks of Pliocene–Pleistocene age, active faults. The Neotectonic evidences were recognized using satellite images and the existing Neotectonic data, and validated in the field.

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  • Lönnqvist, Joel
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hjelm, Jonathan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Impacts of monoculture and mixed vegetation on green roof hydrological function2019In: Urban Water: Novatech 2019, Graie , 2019Conference paper (Other academic)
    Abstract [en]

    A dense vegetation cover is usually desired to fulfil aesthetical expectations of green roofs, and therefore stress tolerant Sedum vegetation has traditionally been favoured for extensive green roofs. However, Sedum species’ low water use and low root biomass could prove suboptimal for the hydrological function of green roofs compared to vegetation’s with different resource use. This study looks at the hydrological performance of four different vegetation mixtures grouped based on Grime’s C-S-R life strategies a Sedum monoculture and a non-vegetated control. Runoff from seven rainfall events (3.4–8.4 mm) was recorded during one autumn season when temperatures were getting lower (6–13˚C) The results showed no relationship between vegetation cover and retention, and the roofs planted with a stress tolerant mixtures of species showed the greatest overall retention. Roofs planted with Sedum monoculture had the greatest vegetation cover but the lowest mean retention.

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    JL novatech 2019
  • Nilsson Thapnoi, Carl Magnus
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Planering och driftsättning av kontors-LAN2020Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The company Imega Media/IT has planned an upgrade for the network within one of the company departments called Display. Hardware is implemented in order to establish a local network and replace the installed Cat5 Ethernet cables with the Cat6 version in order to achieve a higher connection speed. This report documents steps taken in order to analyze and in the best possible way implement the planned upgrade, based on offered hardware and configuration requirements. With the help of a sketch, covering the network topology, one could state that no secondary route existed towards the end switches, therefore guaranteeing that no switching loops could appear after the final installation. Based on the documented topology, improved Ethernet cabling and new hardware were implemented, establishing a new local network. Finally, by using existing hardware resources within the upgraded network, measurements could be made to guarantee that a gigabit speed was reached.

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  • Chen, Shiwei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Lu, Weizhuo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Dehghanimohammadabadi, Mohammad
    Northeastern University, Boston.
    Emborg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Wang, Yaowu
    Harbin Institute of Technology.
    Kailun, Feng
    Harbin Institute of Technology.
    Concrete Construction: How to Explore Environmental and Economic Sustainability in Cold Climates2020In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 12, no 9, article id 3809Article in journal (Refereed)
    Abstract [en]

    In many cold regions around the world, such as northern China and the Nordic countries,on‐site concrete is often cured in cold weather conditions. To protect the concrete from freezing or excessively long maturation during the hardening process, contractors use curing measures. Different types of curing measures have different effects on construction duration, cost, and greenhouse gas emissions. Thus, to maximize their sustainability and financial benefits, contractors need to select the appropriate curing measures against different weather conditions. However, there is still a lack of efficient decision support tools for selecting the optimal curing measures, considering the temperature conditions and effects on construction performance. Therefore, the aim of this study was to develop a Modeling‐Automation‐Decision Support (MADS) framework and tool to help contractors select curing measures to optimize performance in terms of duration, cost, and CO2 emissions under prevailing temperatures. The developed framework combines a concrete maturity analysis (CMA) tool, a discrete event simulation (DES), and a decision support module to select the best curing measures. The CMA tool calculates the duration of concrete curing needed to reach the required strength, based on the chosen curing measures and anticipated weather conditions. The DES simulates all construction activities to provide input for the CMA and uses the CMA results to evaluate construction performance. To analyze the effectiveness of the proposed framework, a software prototype was developed and tested on a case study in Sweden. The results show that the developed framework can efficiently propose solutions that significantlyreduce curing duration and CO2 emissions.

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  • Rönnlund, Tanja
    et al.
    Luleå University of Technology, Department of Health Sciences.
    Eriksson, Emma
    Luleå University of Technology, Department of Health Sciences.
    Barriärer hos vårdpersonal mot att göra orosanmälan vid misstanke om att barn far illa: En integrerad litteraturöversikt2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Barnmisshandel är ett samhällsproblem i Sverige men även globalt.  Trots att det i flera länder är lagstadgat att vårdpersonal ska anmäla misstanke om att ett barn far illa finns det ett stort mörkertal som aldrig anmäls inom vården. Misshandel påverkar barnets utveckling negativt samt att det kan ge konsekvenser för barnet resten av livet, vilket i sin tur leder till stora kostnader för samhället. Syftet med denna studie var att sammanställa kunskap om vilka barriärer vårdpersonal har att göra en orosanmälan i samband med misstanke om att barn far illa. En integrerad litteraturöversikt gjordes där 12 artiklar som svarade mot syftet analyserades enligt Whittemore och Knafls (2005) analysmetod. I resultatet framkom fem kategorier om barriärer. Dessa var barriärer som grundas i olika grader av acceptans, barriärer som grundas i brister i lagen, arbetsplatsen samt kunskapen, barriärer som grundas i individuella osäkerheter samt svåra känslomässigt laddade fall, barriärer som grundades i bristande samarbete och stöd och barriärer som grundades i en rädsla för eventuella konsekvenser. Vårdpersonal ansåg att bristande riktlinjer, bristande kunskap om lagen, identifierings- och anmälningsprocessen samt om ämnet barnmisshandel var en barriär. Vårdpersonalen upplevde även osäkerhet om sina egna bedömningar och bristande samarbete mellan vårdpersonalen socialtjänsten som barriärer mot att anmäla sin oro gällande barn. Genom att förtydliga och utveckla riktlinjer samt utveckla utbildningen för vårdpersonal inom ämnet barnmisshandel kan vårdpersonal känna sig tryggare med att göra orosanmälningar. Detta kan leda till att de utsatta barnen och familjerna får hjälp tidigare.

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  • Persson, Dennis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Byggnadsdelars klimatpåverkan i träbyggnadssystem: En jämförelse för optimering2020Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    Sweden is a country that is enriched by forest. This provides Sweden with the opportunity of having a lot of locally produced wooden building components. In brief, this means that we have a renewable source that will always be accessible if we utilize it in a correct manner. This grants a lot of benefits for the environment and creates a greater interest of practicing wooden building systems and the use of other wooden based materials in all sorts of buildings. When it comes to building components there are different choices that has to be done in order to overcome certain requirements regarding acoustics, fire safety, thermal conductivity and load bearing capacity. The purpose of this study is to show, based on the climatic impact, which decisions and materials to focus on when constructing buildings in wooden building systems. Here, the climatic impact from walls are thoroughly studied and the impact from slabs are given a general insight. The walls are using either cross-laminated timber (CLT) or studs made from construction timber.

     

    The walls are formed by the author and all calculations regarding thermal conductivity, load bearing capacity and fire safety are made in Excel. The only exception is the load bearing capacity during a fire for walls using CLT where the software SPFit2.0 have been used. No calculations regarding acoustics have been made. A functional unit is the frame that forms the requirements that has to be met by every studied building component in order to make the results comparable between the different building components. The reference project for this study is a two-story preschool and the functional unit is based on that reference building. A total of 60 walls have been studied, consisting of both outer and inner walls. The results are based upon life-cycle analysis and are produced from a software called Byggsektorns Miljöberäkningsverktyg (BM). Only two slabs have been studied whereas both use CLT. The slabs are taken from already existing projects that consists of a two-story preschool using a wooden building system.

     

    The results show that plasterboards designed to withstand fire better are recommended to be avoided in these wooden building systems. Instead, the preferred coverings are regular plasterboards and single wooden based coverings where possible. Cellulose insulation and rockwool are the favored insulation materials rather than glass wool. The density of the rockwool may have a large impact on the result and is recommended to keep low. The optimisation of walls, based on climatic impact, is shown to not be a sub-optimisation, although the majority of the climatic impact comes from slabs. Optimised walls can result in a reduce of 7 percent on every floorplan and may also be higher. Even different variations of walls within the same wooden building system may cause large changes on the climatic impact.

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  • Tesfamicael, Adiam
    et al.
    Luleå University of Technology, Department of Health Sciences.
    Aguirre, Carmen
    Luleå University of Technology, Department of Health Sciences.
    Personers upplevelse av att leva med tuberkulos: en litteraturstudie2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Tuberkulos är en infektionssjukdom som räknas till en av de tio vanligaste dödsorsakerna i världen och miljontals människor fortsätter årligen att insjukna. I Sverige är sjukdomen ovanlig men däremot har det skett en liten ökning under 2000-talet. Syftet med denna litteraturstudie var att beskriva personers upplevelse av att leva med tuberkulos. Systematiska sökningar genomfördes i databaserna PubMed och Cinahl vilket resulterade i tio artiklar som ingick i analysen. Kvalitativ innehållsanalys med manifest ansats användes för att analyser artiklarna. Analysen resulterade i fyra kategorier: Att diagnos och behandling både är oroande och hoppfullt, Att känna sig isolerad och vara rädd att smitta andra, Att känna sig utpekad och inte våga berätta och Att få stöd och tröst är betydelsefullt. Resultatet visade att personer som lever med tuberkulos upplevde mycket oro och rädsla för sjukdomen. De upplevde också skam, isolering och ensamhet i sjukdomen. De beskrev även att samhället i stort behandlade dem illa och de kände sig utstötta. Denna litteraturstudie kan bidra till att sjuksköterskor får kunskap om vad det innebär för personer att leva med sjukdomen. Baserat på detta kan sjuksköterskor stötta och hjälpa personer att hantera sjukdomen och nå en god hälsa trots sjukdom.

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  • Öbom, Christoffer
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Grönområden under mörkrets timmar: En studie om trygghet i städernas parker och grönområden under kvälls- och nattetid2020Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Parks and green areas are important to a city and have many different characteristics and functions, both for individuals and the climate challenges society is facing.

    For the people they offer a place to socialize, relax and enjoy while promoting biodiversity, taking care of stormwater and giving character to the city. When these green spaces are presented to the public, they are raised as attractive, inviting and safe where there is the opportunity for various activities during the day. But in the evening and night time, their character is at risk of changing as darkness falls, the place is depopulated and people's movement patterns change. This work focuses on studying people's perceptions on sense of safety today in parks and green areas in cities during the evening and night hours, and what physical factors that cause this perception.

    The study is designed as a survey that has been sent out by e-mails and social media to people all over Sweden. The survey asks questions about people's own perceptions on sense of safety in urban parks and green areas during the evening and night hours, what physical factors affect, the view of the municipalities' communication and the work of the authorities. The result shows that people in the cities are not feel safe in our parks and green areas during the dark hours of the day. It also shows that people avoid moving or staying in parks and green areas during the evening and night hours. From the survey it is possible to find out which physical factors that affect people perception of safety, such as the size and location of the vegetation, lighting and unclear walking paths. From these affecting physical factors it is shown that dark places are the larges factor for felling of safety. The survey respondents also state that with a higher presence of police and more cameras deployed, the feeling of safety would increase. With the public's views of what gives the felling of safety nowday agains municipalities' safety work proves here that they have not succeeded. The result of the study gives room to for a discussion about strengthening the physical environment in our parks and green areas.

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  • Andersson, Lina
    Luleå University of Technology, Department of Arts, Communication and Education.
    ”Man är ju medborgarnas ögon och öron”: En kvalitativ studie av lokalredaktörers syn på sin roll i dagens medielandskap2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Based on the current situation in the media and the fact that newspapers have cut down on journalists over the last ten to fifteen years, especially those located in small, remote areas, the main purpose of this thesis was to study how all the remaining local editors in rural Västerbotten think of their role and what their driving forces are as well as what challenges and opportunities they face in their everyday work life.

    Qualitative interviews were conducted with all the seven local editors who currently work in rural Västerbotten and then analyzed through theories of local journalism and democracy, a media landscape in constant change, journalistic profession and identity.

    The results showed that their role is complex and has plenty of contradictions. Their driving forces and ambitions conflict with their work situation. While they are driven by high democratic standards in their work, they feel that they don’t have enough time for investigative journalism as a lot of their time goes to reporting from at least two municipalities each. They also express that the one municipality where they don’t live doesn’t get as much coverage as they would like and is somewhat forgotten.

    A lot of them are well known in the place where they live and work and some people feel a close connection to the newspaper because of them. Many of them also have difficulties stepping out of their role in their spare time. At the same time, they express that they don’t have the same contact with readers like they used to. They are close but at the same time distanced from their readers.

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  • Runebjörk, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Evaluering av kontextmodeller och interaktiva virtuella miljöer i den arkitektoniska gestaltningsprocessen2020Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    The tools available to architects in the design process are constantly being enhanced and developed, which paves the way to try out new methods and techniques. The current widespread availability of commercial drones, sophisticated surveying instruments and advanced calculation software, makes it possible to create detailed digital representations of reality, in the form of context models. Context models in combination with real-time rendering, through game engines and visualization with the help of Interactive Virtual Environments (IVE), lets architects recreate planned buildings in a realistic virtual context. The study examines how the architect can leverage the benefits of context models and IVE in the architectural design process and presents a method which can be used by architect- and consultant firms. A qualitative research method is used to accomplish this goal, where data is gathered through interviews and a workshop with practicing architects, but also a case study is performed to evaluate the presented method. All the collected data is compartmentalized and analyzed with a method called Pattern Matching, where expected theoretical patterns are compared to the empirical data that appear from the collected data. The study shows that the use of context models and IVE has great benefits in several varying phases of the design process, where benefits in communication is presented as the main contributing factor. With that said, there are concerns regarding implementation of the tools in early stages of the design process, where the possibility to present a misleading IVE is regarded as a potential risk. A presented benefit of using context models and IVE is the ability to create virtual presence. Also, the ability to present the building in its real context proved to be a great benefit in the study. These are closely tied to the benefits of IVR (Immersive Virtual Reality), in cases where visualization of volumes and spaces is needed, which is enhanced by a detailed context model. Finally, a method for architects and consultants to use context models and IVE in the design process is presented. The method is summarized to involve different expertise in the organization to carry through different tasks in the workflow, in order to let the architect focus on the design of the building, but still leverage the benefits of the visualization tools. A conclusion that is drawn, is that the presented method needs to be evaluated further, in order to prove its efficiency. If that is the case, the method might be a step in a new path for the ever changing role of the architect.

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  • Bäck, Carl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Evaluation of high-level synthesis tools for generation of Verilog code from MATLAB based environments2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    FPGAs are of interest in the signal processing domain as they provide the opportunity to run algorithms at very high speed. One possible use case is to sort incoming data in a measurement system, using e.g. a histogram method. Developing code for FPGA applications usually requires knowledge about special languages, which are not common knowledge in the signal processing domain. High-level synthesis is an approach where high-level languages, as MATLAB or C++, can be used together with a code generation tool, to directly generate an FPGA ready output. This thesis uses the development of a histogram as a test case to investigate the efficiency of three different tools, HDL Coder in MATLAB, HDL Coder in Simulink and System Generator for DSP in comparison to the direct development of the same histogram in Vivado using Verilog. How to write and structure code in these tools for proper functionality was also examined. It has been found that all tools deliver an operation frequency comparable to a direct implementation in Verilog, decreased resource usage, a development time which decreased by 27% (HDL Coder in MATLAB), 45% (System Generator) and 64% (HDL Coder in Simulink) but at the cost of increased power consumption. Instructions for how to use all three tools has been collected and summarised.

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  • Lönnroos, Jenny
    Luleå University of Technology, Department of Arts, Communication and Education. Jenny Carola Lönnroos.
    Specialpedagogik som verktyg för ett inkluderande geografilärarskap2020Student paper other, 12 HE creditsStudent thesis
    Abstract [sv]

    Abstrakt

    Genom aktionsstudien ville jag söka svar på hur jag som geografilärare kunde dra nytta av specialpedagogiken för att bättre möta alla elever och skapa en mer inkluderande undervisning. I aktionsstudien sökte jag därför under 7 aktioner i en klass i årskurs åtta besvara frågan ”Hur kan jag som geografilärare planera och genomföra undervisningen med stöd av specialpedagogiska verktyg?”

    För att besvara frågeställningen genomförde jag en studie i en klass som sågs som stökig, pratig och ofokuserad. Två av 23 elever behövde läs- och skrivstöd. Klassmentorn berättade att flertalet elever efterfrågat förbättrad arbetsro och koncentration. Utifrån klassens och individernas behov blev min utgångspunkt att skapa en lärmiljö som gav ökade förutsättningar för läsning- och skrivning samt ökad koncentration. Eftersom jag även ville skapa mig en uppfattning om den kvalitativa effekten av undervisningen lät jag också undersöka elevernas upplevelse genom en elevenkät med delvis öppna svar. Mina egna och min lokala lärarhandledares observationer blev ytterligare underlag för att genomföra och analysera undervisningen.

    Med stöd i relationella, sociokulturella och reflektionsteoretiska perspektiv kunde jag planera och genomföra undervisningen. Fysiska, pedagogiska och psykosociala verktyg gav mig och eleverna stöd. Min uppfattning var att desto längre in i aktionsstudien klassen kom desto fler elever nyttjade verktygen och desto bättre arbetsro blev det i klassen. En uppfattning som enkätundersökningen bekräftade. 16 av 17 elevrespondenter menade i enkäten att de använt något eller några av de verktyg jag tillhandahållit och att de bedömde sin koncentration som bra eller jättebra. Vidare menade 9 av 12 elevrespondenter att de upplevde en förbättring av arbetsron i klassen under perioden för studien. Med stöd i vetenskaplig teori och specialpedagogiska verktyg formades en inkluderad lärmiljö och mer lustfylld geografiundervisning. En lärmiljö som även kan ses ur ett allmändidaktiskt perspektiv.

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  • Lundbäck, Emma
    et al.
    Luleå University of Technology, Department of Health Sciences.
    Lundmark, Edvin
    Luleå University of Technology, Department of Health Sciences.
    Sjuksköterskors attityder och erfarenheter av att vårda patienter som nyligen vårdats på en intensivvårdsavdelning: en integrerad litteraturöversikt2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Patienter förflyttas från IVA till vårdavdelningar tidigare i sjukdomsförloppet vilket resulterar i att patienters vårdbehov fortfarande är komplext för en sjuksköterska på en vårdavdelning. Det ställs höga krav på sjuksköterskor som vårdar en patient med allvarlig sjukdom med avseende på den vård som är möjlig att bedriva på vårdavdelningar. Syftet med denna litteraturöversikt var att sammanställa sjuksköterskor attityder och erfarenheter av att vårda en patient som nyligen vårdats på en intensivvårdsavdelning. För att besvara syftet användes Whittemore och Knafls (2005) analysmetod för en integrerad litteraturöversikt. Analysen resulterade i sju huvudgrupper: Osäkerhet och otillräcklighet, Avsaknad av resurser, Krav från patienter och närstående, Bristande kommunikation, Ökad delaktighet vid överflyttning, Förbättrad kommunikation och Bättre samarbete med IVA-sjuksköterskor. I resultatet framkom att sjuksköterskor kunde känna oro inför att en patient skulle överflyttas från IVA. Sjuksköterskor uttryckte en känsla av otillräcklighet, avsaknad av resurser och bristande kommunikation som påverkade deras möjligheter att bedriva god vård. Sjuksköterskor föreslog att de skulle få vara en större del i planeringen och utförandet av överflyttningen samt att kommunikationen och samarbetet med IVA-sjuksköterskorna kunde förbättras. Det är viktigt att sjuksköterskor är medvetna om att deras attityder kan överföras till patienter. Kommunikation och samarbete var två viktiga områden som sjuksköterskor önskade förbättrades. Genom en ökad förståelse för sjuksköterskors attityder och erfarenheter synliggörs förbättringsområden. Ett förbättringsområde som föreslås i denna litteraturöversikt är att implementera SBAR i vården för att få en gemensam struktur vid kommunikationen.

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  • Hasbo Olsson, Carl
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Westin, Pontus
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Flaskhalsar i tillredningsprocessen: Zinkgruvan, Lundin Mining2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    The key to a successful production line demands full performance from all steps involved. If an interruption in the production occurs, it may cause the company delays and unnecessary expenses. The idea for this degree project was established when Zinkgruvan mine first brought up the problems with bottlenecks in the drifting process. Thus, the objective of this project was to identify these bottlenecks as well as the reasons for their origin. Furthermore, the results from the bottleneck detection would end up being analyzed and used to suggest solutions to partly, or entirely eliminate the origin of the bottlenecks. Crucial to reach the objective were literature analysis and field studies arranged in the mine. The purpose of literature analysis was to grant deeper knowledge of the subject itself whilst finding mathematical relations which could enable identification of bottlenecks. The main purpose of the field studies was to gather data concerning time whilst achieving a deeper understanding of the production process in the Zinkgruvan mine.

     

    The result ended up with two mathematical relations describing how a bottleneck, in theory, can be detected with respect to capacity and utilization. Those relations combined with the data gathered in the mine generated calculations implying that loading made the bottleneck in both categories, capacity and utilization. Extended infrastructure in the areas where long loading distances occur, became one of the suggested solutions to limit expenditure of time. Another solution suggested was to increase the amount of machinery regarding loading. In the end, the reason as to why loading became the bottleneck turned out to depend on various factors. Amongst others, one reason turned out to be the long mileages back and forth the current working site. The result regarding bottlenecks in the Zinkgruvan mine ended up being only a generalization, thus, a very important conclusion states that more data regarding time is required to make the result statistically significant.

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  • Sayahi, Faez
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Emborg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Hedlund, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Cwirzen, Andrzej
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Stelmarczyk, Marcin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Modelling the Severity of Plastic Shrinkage in Cementitious Materials2020In: Proceedings of the international Conference on Civil Infrastructure of Construction (CUSC 2020), Qatar University Press , 2020, p. 566-573Conference paper (Other academic)
    Abstract [en]

    Plastic shrinkage cracking in cement-based materials occurs between the mixing and the final setting of the mixture, where rapid evaporation of the mixed water is the main cause behind the phenomenon. The induced cracks may impair the durability and sustainability of the structure by facilitating ingress of harmful materials into the concrete bulk. In this paper a new model for estimating the cracking severity of plastic cementitious materials is presented based on the mixture’s initial setting time and the amount of the pore liquid evaporated from within the concrete mass. Results of experiments performed by the authors in another study, in addition to results of tests performed by other researchers are used to control the validity of the model. It is concluded that the model can anticipate the cracking severity of plastic concretes with good precision. The new method can provide practical tools for designers and contractors to predict and compare the cracking risk of the concretes prior to casting.

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    Modelling the Severity of Plastic Shrinkage in Cementitious Materials
  • Mukkavaara, Jani
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Sandberg, Marcus
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Sandberg, Karin
    RISE – Research Institutes of Sweden, Laboratorgränd 2, SE-93177, Skellefteå, Sweden.
    Pousette, Anna
    RISE – Research Institutes of Sweden, Laboratorgränd 2, SE-93177, Skellefteå, Sweden.
    Norén, Joakim
    RISE – Research Institutes of Sweden, Laboratorgränd 2, SE-93177, Skellefteå, Sweden.
    Sustainability evaluation of timber dwellings in the north of Sweden based on environmental impact and optimization of energy and cost2020In: Procedia Manufacturing, E-ISSN 2351-9789, Vol. 44, p. 76-83Article in journal (Refereed)
    Abstract [en]

    Identifying design variations that strike the balance between environmental, energy and cost can be aided using multi-objective optimization. From the resulting Pareto-solutions, selecting a single optimal solution remains a challenge. Thus, research is still needed to increase the practical use of optimization for architectural, engineering and construction (AEC) practitioners. This paper presents the use of an optimization approach where the results and an environmental assessment are discussed with AEC practitioners. The method was tested in two case studies: a prestige tourist cottage and a multifamily residential building. Different superstructures, insulation materials and windows were varied for the cottage’s envelope whilst evaluating life-cycle energy and cost. In addition, the environmental impact in terms of CO2 emissions was evaluated for the initial and optimal design suggestions for the two different superstructures. For the residential building, the insulation material thickness and the windows were varied for its evaluation of life-cycle energy and cost. For the cottage, a report was written and then read by the practitioners and used as a base for future decisions. For the residential building, the results were presented orally for the practitioners. In both cases, it was possible to communicate the overarching results of the optimizations through visual plots, although future research should find ways to also explain the detailed results.

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  • Cao, Yongkang
    et al.
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China College of Chemical Engineering and Environment, China. University of Petroleum, Beijing, Beijing, China.
    Zhang, Xiangping
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. College of Chemical and Engineering, University of Chinese Academy of Sciences, Beijing, China.
    Zeng, Shaojuan
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Liu, Yanrong
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Dong, Haifeng
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Deng, Chun
    College of Chemical Engineering and Environment, China University of Petroleum, Beijing, Beijing, China.
    Protic Ionic Liquid‐Based Deep Eutectic Solvents with Multiple Hydrogen Bonding Sites for Efficient Absorption of NH32020In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, no e16253Article in journal (Refereed)
    Abstract [en]

    The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL‐based deep eutectic solvents (DESs) for NH3 absorption. The results indicated that these PIL‐based DESs not only have fast absorption rate, but also exhibit exceptional NH3 capacity and excellent recyclability. The highest mass capacity of 211 mg NH3/g DES was achieved by [Im][NO3]/EG with molar ratio of 1:3, and was higher than all the reported ILs and IL‐based DESs, which was originated from multiple hydrogen bonding between acidic H and hydroxyl groups of the DESs and NH3. This work will provide useful idea for designing IL‐based solvents for NH3 separation applications.

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  • Public defence: 2020-06-10 10:00 Hörsal A, Skellefteå
    Islam, Raihan Ul
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    An Improved Belief Rule-Based Expert System with an Enhanced Learning Mechanism2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Belief rule-based expert systems (BRBESs) are widely used in various domains which provide an integrated framework to handle qualitative and quantitative data by addressing several kinds of uncertainty. The correctness of the data significantly affects the accuracy of the BRBESs. Learning plays an important role in BRBESs to upgrade their knowledge base and parameters values, necessary to improve the accuracy of prediction. In addition, comparatively larger datasets hinder the accuracy of BRBESs.

    Therefore, this doctoral thesis focuses on four different aspects of BRBESs, namely, the accuracy of data, multi-level complex problem, learning of BRBES, and accuracy of prediction for comparatively large dataset.

    First, the accuracy of data acquisition plays an important role, necessary to ensure accurate prediction in BRBESs. Therefore, the data coming from sensors contain anomaly due to various types of uncertainty, which hampers the accuracy of prediction. Hence, anomalous data needs to be filtered out. A novel algorithm based on belief rule base for detecting the anomaly from sensor data has been proposed in this thesis.

    Second, BRBESs can be considered to handle the multi-level complex problem like the prediction of a flood as they address different types of uncertainty. A web based BRBES was developed for predicting flood which provides better usability, allows handling of larger numbers of rule bases, and facilitates scalability. In addition, a learning mechanism for multi-level BRBESs has been developed by taking account of flooding, considered as an example of a complex problem. This learning mechanism for multi-level BRBES demonstrates promising results in comparison to other machine learning techniques including, Long Short-term Memory (LSTM), Artificial neural network (ANN), Support Vector Machine (SVM), and Linear regression.

    Third, different optimal training procedures used to support learning in BRBESs. Among these, Differential Evolution (DE) appears performing better in comparison to other evolution algorithms, including Particle Swarm Optimisation (PSO) and Genetic Algorithm (GA). However, DE's performance depends considerably in assigning near-optimal values to its control parameters. Therefore, an enhanced belief rule-based adaptive differential evolution (eBRBaDE) proposed in this thesis with the capability of ensuring balanced exploitation and exploration in the search space by providing near-optimal values to the DE's control parameters. The capability of accurate prediction of eBRBaDE has been demonstrated by taking account of power usage effectiveness (PUE) of datacentre in comparison to other evolutionary algorithms used in BRBESs optimal training procedures.

    Fourth, the recent advancement of sensor technologies enabled acquiring of a huge amount of data. In this context, deep learning appears as an effective method to process this huge amount of data. However, this high volume of data contains various types of uncertainties, including vagueness, imprecision, randomness, ignorance and incompleteness. Hence, an enhanced deep learning approach, named BRB-DL, has been developed by integrating BRBES, allowing the improvement of prediction accuracy, especially in case of a large dataset. The applicability of this BRB-DL has been carried out by considering a large amount of air pollution data to predict the air quality index (AQI) of different Chinese cities.

    In the light of the above, it can be argued that the novel anomaly detection algorithm proposed in this thesis enables the removing of anomalous data. The proposed learning mechanism for multi-level BRBES allows handling of the multi-level complex problem. The optimal training procedure, named eBRBaDE, enabling determination of optimal learning parameters of BRBESs and finally, the integration of deep learning with BRBES allows to handle large data set.

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  • Sundström, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science. Luleå tekniska universitet.
    Checklist for safe and attractive mining workplaces2020Other (Other academic)
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  • Public defence: 2020-06-05 10:00 E130, Lulea
    Sun, Yunhao
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Modeling ionic liquids with ePC-SAFT ─ properties and gas solubilities2020Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Global warming is now widely recognized as being the biggest global issue facing human beings. Mitigating CO2 emission from fossil-fueled power plants as well as from transports has become an urgent and worldwide research topic, in which CO2 separation is often needed. Technologies have been developed and commercialized, whereas the cost is still high. Developing new technologies for CO2 separation is one focus research area. Ionic liquids (ILs) are promising absorbents for CO2 separation due to their very low vapor pressure, high solubility and selectivity for CO2 as well as low energy usage for solvent regeneration. To develop IL-based technologies, thermodynamic properties (density, heat capacity, gas solubility, etc.), viscosity, and surface tension of ILs are the prerequisites. As the number of ILs that can be theoretically synthesized is up to an order of 1018, determining all the properties experimentally is impractical, not to mention the time-consuming with high cost. It is desirable to develop theoretical tools to predict the thermodynamics and transport properties of ILs and IL-containing mixtures in a wide temperature and pressure range. In our previous work, the framework of ion-specific electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT) has been developed with reliable results. However, the work is still limited to the imidazolium-based ILs, and the model performance for other commonly used ILs is still unclear. Meanwhile, it has been pointed out that the model with the parameters fitted to the experimental data may result in pitfalls, and further validation is needed. In this thesis, the ion-specific ePC-SAFT was further developed and extended to the ILs which are composed of the IL-cations ([Cnmim]+ , [Cnpy]+ , [Cnmpy] + , [Cnmpyr]+ , and [THTDP]+ ) and the IL-anions ([Tf2N]- , [PF6] - , [BF4] - , [tfo]- , [DCA]- , [SCN]- , [C1SO4] - , [C2SO4] - , [eFAP]- , Cl- , [Ac]- , and Br- ). Before modeling the properties, a method and scheme were developed to investigate the pitfall when modeling IL with ePC-SAFT. All 96 ILs considered in the thesis were covered. The investigation shows that for most ILs (86 of 96 ILs), the additional fictitious critical temperature is low enough not to affect the calculations at a normal temperature range, and after further phase equilibrium calculation, only one IL ([C8mpy][BF4]) may generate a risk of pitfall occurrence at the temperature and pressure of interest for CO2 separation. The parameters for [Cnmpy]+ may need to be modified in future work. The prediction of the derivative properties (isobaric heat capacity, isochoric heat capacity, speed of sound, isentropic compressibility coefficient, isothermal compressibility coefficient, thermal expansion coefficient, thermal pressure coefficient, and internal pressure) combined with the comparison to the available experimental data shows that ePC-SAFT can provide reliable results for most ILs. ePC-SAFT was used to predict the CO2 solubilities in 46 ILs, and the prediction agrees well with the experimental data in a wide temperature and pressure range for 36 ILs. The addition of an ion-specific binary ii parameter between IL-ion and CO2 can further improve the model performance significantly for the 10 ILs with relatively poor model performance. ePC-SAFT can also provide a reliable prediction for the solubility of other pure gases (CH4, CO, H2, N2, and O2). To further verify the model performance on the viscosity of ILs, ePC-SAFT coupled with the free volume theory (FVT) (i.e., ePC-SAFT-FVT) was studied. Two strategies were applied to adjust the FVT parameters, i.e., molecular-based approach with parameters for each IL (strategy 1) and IL-cation molecular-weight linearized parameters for the ILs in the same homologous series (strategy 2). The comparison with the available experimental viscosities for 96 ILs shows that the strategy 1 can provide reliable results for 89 ILs in a wide temperature and pressure range, while strategy 2 can provide almost similar reliable results as strategy 1. ePC-SAFT-FVT can be further used to predict the viscosity of ILmixtures reliably. The model ePC-SAFT-DGT, i.e., the coupling of ePC-SAFT with the density gradient theory (DGT), was further developed and used to model the interfacial properties of ILs. The comparison with the available experimental surface tensions for 82 ILs shows that the model can represent the surface tension reliably, and the use of the anion-specific influence parameters linearized with the molecular weights of IL-cations allows predicting the surface tension of the ILs in the same homologous series. The density profile on the vaporliquid interface can be further predicted with the influence parameter adjusted by the surface tension. In summary, the ion-specific ePC-SAFT is a suitable tool for IL-systems, which can be highly recommended to be applied in industrial design and optimization.

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  • Bapeer, Galawezh Bakr
    et al.
    Department of Geotechnical Engineering, Faculty of Engineering, Koya University, Koya, Kurdistan Region, Iraq.
    Muhammad, Rozhgar Kamal
    Directorate of Slemani Construction Laboratory, Sulaimaniya, Kurdistan Region, Iraq.
    Nadr, Kazhan Akram
    Directorate of Slemani Construction Laboratory, Sulaimaniya, Kurdistan Region, Iraq.
    Khodakarami, Loghman
    Department of Petroleum Engineering, Faculty of Engineering, Koya University, Koya, Kurdistan Region, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Geotechnical Properties of Soil in Ranya and Arbat Area, Sulaimaniya, Kurdistan Region, Iraq2020In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 10, no 5, p. 35-48Article in journal (Refereed)
    Abstract [en]

    This study deals with the determination of some geotechnical properties of soil in Ranya district and Arbat sub-district area. These two areas are located in Sulaymaniya Governorate, Kurdistan region of Iraq. The soil in nature is changing from one place to another. This is because of the mineral composition of rocks and climate change, so, studying the properties of soil is important for various purposes especially for engineering structures. In this paper, some geotechnical soil were studied, like particle size distribution, specific gravity and Atterberg limits. The study of particle size distribution indicated that the soil comprises mostly of silt and sand with some clay. This means that the soil consists of coarse and fine mixture. The Atterberg limits results are indicating that both areas are characterized by low to medium plasticity index. Specific gravity test results are indicating that the soil in both areas is free from iron and mica minerals. A good matching of the geotechnical soil properties between Ranya and Arbat area is indicated. 

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