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  • 1.
    Adam, Rania E.
    et al.
    Department of Sciences and Technology, Linköping University, Norrköping, Sweden.
    Chalangar, Ebrahim
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS). Department of Sciences and Technology, Linköping University, Norrköping, Sweden.
    Pirhashemi, Mahsa
    Department of Chemistry, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran.
    Pozina, Galia
    Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, Sweden.
    Liu, Xianjie
    Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, Sweden.
    Palisaitis, Justinas
    Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping, Sweden.
    Pettersson, Håkan
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS). Department of Sciences and Technology, Linköping University, Norrköping, Sweden & Solid State Physics and NanoLund, Lund University, Lund, Sweden.
    Willander, Magnus
    Department of Sciences and Technology, Linköping University, Norrköping, Sweden.
    Nur, Omer
    Department of Sciences and Technology, Linköping University, Norrköping, Sweden.
    Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities2019Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 52, s. 30585-30598Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-efficiency photocatalysts are crucial for the removal of organic pollutants and environmental sustainability. In the present work, we report on a new low-temperature hydrothermal chemical method, assisted by ultrasonication, to synthesize disruptive plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis. The plasmonic nanocomposites were investigated by a wide range of characterization techniques, confirming successful formation of photocatalysts with excellent degradation efficiency. Using Congo red as a model dye molecule, our experimental results demonstrated a photocatalytic reactivity exceeding 90% efficiency after one hour simulated solar irradiation. The significantly enhanced degradation efficiency is attributed to improved electronic properties of the nanocomposites by hybridization of the graphene and to the addition of Ag/AgI which generates a strong surface plasmon resonance effect in the metallic silver further improving the photocatalytic activity and stability under solar irradiation. Scavenger experiments suggest that superoxide and hydroxyl radicals are responsible for the photodegradation of Congo red. Our findings are important for the fundamental understanding of the photocatalytic mechanism of ZnO/graphene/Ag/AgI nanocomposites and can lead to further development of novel efficient photocatalyst materials. © 2019 Elsevier B.V.

  • 2.
    Bhatti, Muhammad Ali
    et al.
    Department of Environmental Sciences University of Sindh Jamshoro, Sindh, Pakistan.
    Shah, Aqeel Ahmed
    NED University of Engineering and Technology Karachi, Pakistan.
    Almani, Khalida Faryal
    Department of Environmental Sciences University of Sindh Jamshoro, Sindh, Pakistan.
    Tahira, Aneela
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, Sweden.
    Chalangar, Ebrahim
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, Sweden.
    Chandio, Ali dad
    NED University of Engineering and Technology Karachi, Pakistan.
    Nur, Omer
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, Sweden.
    Willander, Magnus
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, Sweden.
    Ibupoto, Zafar Hussain
    Institute of Chemistry University of Sindh Jamshoro, Sindh, Pakistan.
    Efficient photo catalysts based on silver doped ZnO nanorods for the photo degradation of methyl orange2019Ingår i: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the doped ZnO nanorods with silver (Ag) as photosensitive material are prepared by the solvothermal method. The structural and optical characterization is carried out by the scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy and UV–visible spectroscopy. The use of Ag as dopant did not alter the morphology of ZnO except sample 4 which has flower like morphology. The Ag, Zn and O are the main constituent of doped materials. The XRD revealed a hexagonal phase for ZnO and cubic phase for silver and confirmed the successful doping of Ag. The photocatalytic activity of Ag doped ZnO nanorods was investigated for the photo degradation of methyl orange. The photocatalytic measurements show that 88% degradation of methyl orange by the sample 4 within the 2 h of UV light treatment (365 nm) is significant advancement in the photocatalyst and provide the inexpensive and promising materials for the photochemical applications. © 2019 Elsevier Ltd and Techna Group S.r.l.

  • 3.
    Burestedt, E.
    et al.
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Emnéus, J.
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Gorton, L.
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Marko-Varga, G.
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Domínguez, E.
    Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Alcalá de Henares, Spain.
    Ortega, F.
    Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Alcalá de Henares, Spain.
    Narváez, A.
    Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Alcalá de Henares, Spain.
    Irth, H.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands.
    Lutz, Mareike
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands.
    Puig, D.
    Department of Environmental Chemistry, CID-CSIC, Barcelona, Spain.
    Barceló, D.
    Department of Environmental Chemistry, CID-CSIC, Barcelona, Spain.
    Optimisation and validation of an automated solid phase extraction technique coupled on-line to enzyme-based biosensor detection for the determination of phenolic compounds in surface water samples1995Ingår i: Chromatographia, ISSN 0009-5893, E-ISSN 1612-1112, Vol. 41, nr 3-4, s. 207-215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A fully integrated screening system for phenolic compounds was developed incorporating on-line solid phase extraction, fractionation and biosensor detection. Two different types of biosensors, solid graphite and carbon paste electrodes incorporating the enzyme tyrosinase, were compared and used in the screening system. Interfacing of the solid phase extraction and fractionation with the biosensor detection was given special attention since the biosensors were not compatible with the organic modifier used for desorption of phenols from the solid phase extraction step. The system was validated with conventional analytical techniques. Surface water samples from the Ebro river were spiked with 1,10, and 25μg L−1 of catechol, phenol,p-cresol, respectively. Three out of seven samples were spiked and the correct samples were identified, containing phenols equivalent to the spiked concentrations. © 1995 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.

  • 4.
    Claesson, Jenny
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    Hur fungerar en glaselektrod?2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    För att förstå hur glaselektroden fungerar krävs kunskap från mer än ett plan. Glaselektrodenskonstruktion är en del, glasets kemiska struktur en annan. Nernst ekvationen spelar en viktig roll,men även felkällorna i de analyser som görs med glaselektrod, (vanligtvis pH-mätning), samtkalibreringen av glaselektroden. I den här uppsatsen ligger fokus på hur glaselektroden faktisktfungerar och hur Gibbs fria energi gör potentialen beroende av koncentrationen vätejoner och tillförlogaritmen i funktionen för glaselektroden. Nikolskii's ion exchange theory påbörjar förklaringen avpotentialens uppkomst och Baucke's dissociation mechanism gör den tydligare. Skillnaden mellanrespektive teori och dess matematiska funktion är konstantens innebörd och betydelse, men för denpraktiska användningen av glaselektroden till analyser är detta av mindre vikt då konstantens värdefås genom kalibrering. Detta är dock ingen ursäkt för det faktum att the dissociation mechanism geren mer fullständig förklaring och ökad förståelse för hur glaselektroden fungerar än the ionexchange theory.

  • 5.
    Dimkovski, Zlate
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Maskinteknisk produktframtagning (MTEK), Funktionella ytor.
    Bååth, Lars
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Maskinteknisk produktframtagning (MTEK), Fotonik och mikrovågsteknik. Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Maskinteknisk produktframtagning (MTEK), Funktionella ytor.
    Rosén, Stefan
    Toponova AB.
    Ohlsson, Robert
    Volvo Powertrain.
    Rosén, Bengt-Göran
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Maskinteknisk produktframtagning (MTEK), Funktionella ytor.
    Interference Measurements of Deposits on Cylinder Liner Surfaces2011Ingår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 270, nr 3-4, s. 247-251Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The accumulation of deposits in the honing grooves of the cylinder liner surfaces of internal combustion engines is undesirable as they seal the grooves (reducing their oil retention capability) and increase engine's oil consumption. As part of a long-term programme of truck engine development, after different running times and under similar conditions of load, engine speed and lubrication, a number of grey iron cylinder liners were axially sectioned, measured, inspected and a presence of deposits was discovered. These deposits were characterised in order to gain knowledge about their origin and quantities. The X-ray energy dispersive analysis revealed elements stemming from the oil/fuel (C, O and S), from the detergent (Ca and Mg), from the anti-wear additive (Zn and P), and from some contaminants (K and Si). Higher concentration of S and Ca were mostly found in the honing grooves covered with deposits suggesting a domination of the detergent additive. Deposit thickness measurements obtained by a white light interferometer revealed patchy deposit topographies concentrated at the top region reducing towards the bottom of the liner which was also confirmed by scanning electron microscope measurements. Despite the limitations of the interferometer, it has been shown that the interference measurements are sufficiently reliable for a quick and objective quantification of the overall deposit accumulation.

  • 6.
    Hanselius, Anne
    et al.
    Högskolan i Halmstad. Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Eldemark, Karoline
    Högskolan i Halmstad. Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Regulations of catabolic and anabolic mechanisms; the interactions between exercise, carbohydrates and an excessive intake of amino acids: A review of some of the metabolic pathways that affects the homeostasis of the body, as well as β-oxidation and protein synthesis2010Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Insulin as well as glucagon are important hormones in maintaining glucose homeostasis and regulating the metabolism in the body. Insulin receptors (IR) are transmembrane receptors that promote a signal transduction when activated by insulin. This can for example cause an increased influx of glucose into the cell performed by so called glucose transporters (GLUTs). These membrane proteins facilitate the transport of glucose from the blood into the cells, so the cell always has a constant supply of energy. Peroxisome proliferator-activated receptors (PPAR) are nuclear fatty acid receptors. They are activated by lipids and regulate fatty acid transcription. PPARδ/β is located in skeletal muscle and can promote fatty acid catabolism as well as cause a switch in fuel preference from glucose to fatty acids. It has been suggested that ligands for PPARδ could act as insulin sensitizers. The PPARγ coactivator-1α can increase mitochondrial content in skeletal muscle if over expressed. The same is true for endurance exercise.

    Hormones released from adipose tissue can cause hyperphagia and obesity if over- or under expressed. They can also work in the opposite way by decreasing appetite with weight loss as an effect. Impaired signalling or dysfunctional receptor can cause insulin resistance, obesity and diabetes. Lipolysis occurs in adipose tissues and is conducted by three enzymes, namely adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and monoglyceride lipase (MGL). There are some factors that can increase lipolysis such as caffeine, a low glycemic index, high protein intake and training.

    The enzyme PEPCK is involved in the gluconeogensis in the liver and kidney cortex, and also in the glyceroneogenesis in the liver, as well as in brown and white adipose tissue. When overexpressed in skeletal muscle the enzyme increases the muscle activity. The overexpression of the enzyme did promote the β-oxidation as energy source for the muscles during exercise, instead of muscle glycogen as fuel.

    The processes of protein synthesis and breakdown are together called protein turnover. Muscle grows when synthesis is greater than breakdown, and withers if breakdown exceeds the level of synthesis. Acute effects of training is catabolic, but long time exercise causes however an increased protein synthesis. Leucine, an essential amino acid, has an important role in the initiation phase of translation. Glutamine is probably important in the regulation of muscle protein synthesis and breakdown. Together with glutamate, aspartate and asparagine, these are responsible for the amino acid metabolism that occurs in the muscles. Protein synthesis reaches its maximum in the recovery phase after intense training.

  • 7.
    Jogbratt, Arvid
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Kadmium som begränsande faktor för användande av tång som biogassubstrat - en laborativ undersökning:  2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Sveriges miljömål ”Begränsad klimatpåverkan” beskriver ambitionen att fram till år 2020 ska ha minskat utsläppen av växthusgaser med 40 % gentemot år 1990. Ett sätt för Sverige att lyckas med de uppsatta målen är att utveckla biogasproduktionen. Potentialen för biogasproduktion bedöms vara mycket stor och forskning för att ta fram nya substrat att använda inom biogasframställningen pågår. Ett möjligt substrat är alger, dock har tidigare forskning påvisat höga kadmiumhalter i alger vilket kan innebära problem för spridning av rötresten.  

       Syftet med denna rapport var att  genom laborativ och litterär undersökning bedöma algers potential som biogassubstrat och gödningsmedel.

       Resultaten påvisade höga kadmiumkoncentrationer hos alger vilket försvårar en spridning av kadmium till åkermark. De framtagna gränsvärdena för kadmiuminnehåll hos gödningsmedel överskrids för samtliga prover. Det ringa gödningsvärdet hos rötresten grundas i det låga fosforinnehållet hos algerna. Gaspotentialen för rötning av alger med organiskt avfall visade sig vara mycket god, vilket kan motivera en utveckling av effektiva, billiga, reningsmetoder för kadmium. För Halmstad kommun beräknades energiproduktionen av alger att vara av betydelse om ytterligare utveckling av uppsamling och skörd utreds.

       Metoder för kadmiumavskiljning har studerats och i Japan har en effektiv reningsmetod som baseras på urlakning följt av adsorption med naturliga koaguleringsmedel framställda från fruktavfall tagits fram. Andra metoder som möjliggör rötning av alger är att kombinera biogasframställning med produktion av energiskog. Odlingarna kan gödslas med den kadmiumrika rötresten, varefter den skördade energiskogen förbränns och renas från kadmium på förbränningsanläggning.

  • 8.
    Johansson, Emelie
    et al.
    Högskolan i Halmstad, Akademin för lärande, humaniora och samhälle.
    Bergstaf, Sandra
    Högskolan i Halmstad, Akademin för lärande, humaniora och samhälle.
    Mycket mer än bara ett begrepp: En litteraturstudie om lärares undervisningsmetoder för elevers naturvetenskapliga begreppsförståelse i årskurserna F-62018Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Forskning visar att elever inte förstår innebörden av att lära sig naturvetenskap samtidigt som det framgår att ämnet är en naturlig del av människors vardag. Ämnet behöver därför göras förståeligt för att elever ska kunna verka som samhällsmedborgare. Naturvetenskap kan dock ses som svårt då det är ett abstrakt ämnesspråk som ofta uttrycks i naturvetenskapliga begrepp. Samtidigt som det framhålls att elever ska få stöd i sin språkutveckling har det visat sig vara svårt för lärare att göra naturvetenskapligt innehåll förståeligt för eleverna. Syftet med denna systematiska litteraturstudie är att undersöka och beskriva vad forskning säger har betydelse för att möjliggöra att elever i årskurserna F-6 erbjuds kunskaper i naturvetenskaplig undervisning. Mer precist vill vi besvara frågeställningen: Vilka undervisningsmetoder forskning belyser som användbara för lärare att använda för elevers begreppsförståelse inom de naturvetenskapliga områdena? Resultatet av litteraturstudien visar att utveckla pedagogisk innehållskunskap, guidad undervisning, synliggöra ämnets innehåll, ställa frågor och kommunicera naturvetenskap med olika sinnen är undervisningsmetoder som kan tillämpas i den naturvetenskapliga undervisningen för elevers begreppsförståelse. En slutsats blir dock att ingen undervisningsmetod kan appliceras utan en väl genomtänkt stöttning av lärare och att undervisningsmetoden utveckla pedagogisk innehållskunskap kontinuerligt bör utvecklas i takt med undervisningen. Utifrån de resultat som framkommit av litteraturstudien hade det varit intressant att genomföra icke-experimentella undersökningar om lärares undervisningsmetoder för elevers begreppsförståelse i naturvetenskap.

  • 9.
    Johansson, Kim
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    ”Överskott, är det ämnet som får stå i hörnet och vänta” En studie på hur lärarens intentioner uppfattas av eleverna.2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet med studien är att studera lärarens intentioner och hur elever uppfattar lärarens budskap inom kemi på gymnasieskolan. Metoden jag använt mig av är Stimulated Recall. Genom att jag observerat och filmat lektionerna, där jag har träffat lärare och elever var för sig för att reflektera över lektionstillfället. De reflektionsfrågor jag använt mig av är mallen för en så kallad CoRe, som Berry, Loughran & Mulhall (2003) från Australien har utformat. Det är ett reflektionsverktyg men även ett sätt för att exemplifiera PCK (pedagogical content knowledge). PCK är ett begrepp som didaktikforskare använder för att beskriva de egenskaper som en bra lärare skall besitta för att kunna vägleda elever rätt i specifika ämnesområden. Forskare menar att läraren måste ha en god teoretisk grund men även en bra grund i pedagogik.

    Resultatet av studien visar att, om kollegor delger sina erfarenheter till de som är mindre erfarna ger det en utveckling av lärarens PCK och det innebär att lärarens intentioner bättre når fram till eleverna. Responsen från eleverna är mycket positiv och eleverna har en positiv inställning inför kemi, även om många av eleverna tycker att ämnet i sig är ganska svårt.

  • 10.
    Kierkegaard, Andreas
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    Estetisk undervisning i kemi: Estetikens möjligheter och begränsningar ur lärares perspektiv2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Under de senaste två decennierna har kemiresultaten försämrats för elever i grundskolans senare år och i gymnasiet. Elever beskriver ofta kemiämnet som ointressant, svårbegripligt och abstrakt och kemiundervisningen som monoton och gammalmodig. Intresset för kemi är lågt och antalet sökanden till det gymnasiala naturvetenskapsprogrammet har sjunkit. En mer intressant och lustfylld kemiundervisning är därför motiverad.

    Kemiundervisningen tar idag till stor del elevens verbala och logiska intelligenser i anspråk. Elever har även sociala, emotionella, estetiska och kreativa intelligenser och det är en fördel att även använda sig av dessa i inlärningsprocessen. Den aktuella studien fokuserar på ett estetiskt inslag i kemiundervisningen.

    Sju kemilärares uppfattning angående estetisk pedagogik undersöktes i en intervjubaserad kvalitativ studie. Lärarna intervjuades med utgångspunkt från en kort filmsekvens från en kemisal. Resultatet pekade på en betydande variation i synpunkter och inställning till estetisk pedagogik bland de intervjuade lärarna. Utifrån lärarnas inställning till estetisk pedagogik var det möjligt att beskriva fem kategorier med olika synsätt. Det konkluderades att kemilärare rimligen inte utgjorde något hinder för ökat inslag av estetik i kemiundervisningen.

  • 11.
    Kierkegaard, Andreas
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    Etanolmetabolismen ur ett alkoholistperspektiv: Kemin vid nedbrytning av etanol i kroppen, dess betydelse för kroppens kemiska processer i övrigt samt dess betydelse för hälsa och sjukdom2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The present study discusses the metabolism of ethanol in the human body from the ingestion of ethanol to the excretion of its break down products water and carbon dioxide. Ethanol is a small molecule, soluble in water as well as in organic solutions. It is quickly distributed to every section in the body, where it exerts a direct toxic effect on the cells. Ethanol cannot directly leave the body efficiently so it needs other metabolic pathways. The molecule is metabolized by oxidation, predominately in the liver. The enzyme alcohol dehydrogenase catalyses the degradation of ethanol to acetaldehyde. Acetaldehyde is even more toxic than ethanol and it is degraded by the enzyme aldehyde dehydrogenase. In chronic alcoholics other chemical processes such as the cytochrome P450 system may have a bigger impact on alcohol metabolism.

    The carbohydrate metabolism is extensively affected by ethanol. Most important is its restrictive effect on the gluconeogenesis leading to sustained hypoglycaemia in glycogen deprived alcoholics, possibly dangerous for the brain. Ethanol even affects the lipoprotein metabolism leading to evaluated plasma levels of HDL and triglycerides in alcoholics.

    The study also evaluates the genetic polymorphism of the enzymes alcohol dehydrogenase and aldehyde dehydrogenase, metabolic markers for high chronic ethanol consumption, ethanol as an energy supply, ethanol in medical treatment and harmful effects of ethanol and its metabolites on import organ systems in primarily alcoholics.

  • 12.
    Larsson, Marita
    et al.
    DMPK and Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Lutz, Mareike
    DMPK and Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Transient isotachophoresis for sensitivity enhancement in capillary electrophoresis-mass spectrometry for peptide analysis2000Ingår i: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 21, nr 14, s. 2859-2865Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transient isotachophoresic (ITP) focusing was used for the on-line analysis of peptides by capillary zone electrophoresis-mass spectrometry (CZE-MS), allowing injection volumes of up to 0.9 microL. A sheath liquid electrospray interface was used with a single quadrupole mass analyzer. First, the technique was applied to the qualitative analysis of a tryptic digest of cytochrome c, resulting in low-background, high-quality spectra. Second, the linear range was investigated by selected ion monitoring (SIM) for a peptidomimetic direct thrombin inhibitor melagatran (Mr 429.5) and two endogenous peptides, substance P (Mr 1348) and calcitonin gene-related peptide (alpha-CGRP; Mr 3806).

  • 13.
    Lindell, Karolina
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Den lysande återvinningen: - Sammanställning av återvinningslösningar för sällsynta jordartsmetaller (REEs) som förekommer i LED-lampor2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Rare earth metals, REEs, which is a group of metallic elements, are used in LEDs for creating colored light. REEs are produced by mining in different countries, where China accounts for about 90% of global production.

    The recovery of REEs appearing in LED lights are now virtually non-existent and Stena Techno World AB has requested a study showing how the composition of REEs looks for LEDs with the aim to evaluate how a future recovery process might look. This project consisted of a literature review, interviews and field trips.

    REEs is present in extremely small quantities in each LED application, and this makes it very difficult to separate the REEs from the LED in a recycling process. This project has compiled the existing recycling solutions that are used for fluorescents, since  the recovery process theoretically can be the same for the LED lights, if one ignores the fact  that it is difficult to separate  REEs from LED lights. A summary of the presence and quantity of REEs in LED lights with white lights presented in the results section of the project. In the results section is also reported a security strategy developed by the U.S. Department of Energy, where the aim of the strategy is to reduce dependence on China's REE resources.

    The discussion deals with the fact that a separation of REEs is difficult to achieve , and which aspects can justify an investment in recycling technology for REEs appearing in LED lights. The discussion also present calculations of how much of each REE present in the recycling loop of LED lights.

  • 14.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden, Netherlands.
    Burestedt, Elisabeth
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Emnéus, Jenny
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Lidén, Helena
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Gobhadi, Shahpar
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Gorton, Lo
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Marko-Varga, György
    Department of Analytical Chemistry, University of Lund, Lund, Sweden.
    Effects of different additives on a tyrosinase based carbon paste electrode1995Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 305, nr 1-3, s. 8-17Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of a number of solid and chemical additives on the sensitivity and operational stability of a tyrosinase carbon paste electrode was studied. Cyclic voltammograms were run of the electrochemically active catechol/o-quinone couple on unmodified and additive modified carbon paste electrodes without tyrosinase. This was done in order to study the influence of these additives on the pure electrochemistry of the carbon paste. The influence on the total system (additive and enzyme modified carbon paste electrode) was studied in the flow injection mode. In some instances a dramatic improvement of the direct electron transfer of the catechol/o-quinone couple was obtained with both solid and chemical additives included in the carbon paste. A similar improvement of biosensor sensitivity in the flow injection mode was obtained with most chemical additives whereas the solid additives had a negative impact on biosensor sensitivity. The results obtained in this work indicate that these additives influence the purely electrochemical processes at the carbon paste and/or the performance of the enzyme in the carbon paste environment. How and why these additives can possibly influence the biosensor performance are discussed. © 1995.

  • 15.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Dominguez, Elena
    Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Alcalá de Henares (Madrid), Spain.
    Development and Optimization of a Solid Composite Tyrosinase Biosensor for Phenol Detection in Flow Injection Systems1996Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 8, nr 2, s. 117-123Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bulk-modified epoxy-graphite tyrosinase biosensors were fabricated by four different procedures. The influence of these fabrication procedures on the analytical performance of the enzyme electrode in an amperometric wall-jet flow cell has been studied. The bioprobe performance is assessed by cyclic voltammetry. Higher current densities and narrower peaks were obtained when the enzyme was introduced in the dry state into the epoxy-graphite material, instead of introducing it previously dissolved in the buffer. In the FI system responses of 11.79 μA cm-2 and 1.43 μA cm-2 are then obtained for catechol and phenol respectively for 50 μL injections of 20 μM solutions. Moreover, if gold/palladium is introduced into the epoxy-graphite, a further increase in current is achieved resulting in 27.70 μA cm-2 and 4.90 μA cm-2 for catechol and phenol, respectively. This biosensor can operate in aqueous as well as in mixed aqueous-organic environments.

  • 16.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Irth, Hubertus
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Tjaden, Ubbo R.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    van der Greef, Jan
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Applying hollow fibres for separating free and bound label in continuous-flow immunochemical detection1996Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 755, nr 2, s. 179-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    On-line liquid chromatography-immunochemical detection (LC-ICD) provides the possibility to individually monitor cross-reactive compounds overcoming the need of tedious fraction collection. ICD is performed as a post-column reaction detection system and is based on a two-step immunoreaction. In the first step unlabelled antibodies are added to the LC effluent and allowed to react with antigens (analytes) eluting from the LC column. The amount of analytes bound to the antibodies is measured by adding, in a second step, labelled antigen to the reaction mixture. For quantitation, free and bound label need to be separated prior to detection. The present paper describes a hollow fibre module (HFM), which can be used for this purpose. Separation of free and bound label occurs on discrimination by size. Using biotin as a model compound, a detection limit of 30 nmol/l can be reached employing anti-biotin antibodies and a low-molecular-mass fluorescence label in the LC-ICD system. Additional to low-molecular-mass labels, the HFM allows the use of small enzyme labels. In this context, horseradish peroxidase-labelled biotin was used as a label in combination with antibodies in the immunochemical detection of biotin. This allows future implementation of commercially available enzyme immunoassay kits in continuous-flow immunochemical detection.

  • 17.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Irth, Hubertus
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Tjaden, Ubbo R.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    van der Greef, Jan
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands.
    Biochemical detection for direct bead surface analysis1997Ingår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 69, nr 23, s. 4878-4884Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A continuous-now biochemical detection system is presented which recognizes biologically active compounds immobilized to solid phases. This approach can be used to screen, for example, solid-phase combinatorial libraries for lead compounds. Biochemical detection is performed by mixing a plug of a solid-phase suspension with labeled affinity protein, During a short reaction time, the labeled affinity protein will only bind to ligands, i.e., compounds with biological activity. Hereafter, the free and bound labels are separated by means of a hollow fiber module, Quantitation of the free label is performed with a conventional now-through fluorescence detector, Total assay time amounts to less than 3 min. Biochemical detection for direct bead surface analysis was developed for two model systems. The first model system used fluorescence-labeled avidin as affinity protein and its ligands biotin and iminobiotin immobilized to agarose as analytes. The second model system used fluorescence-labeled antisheep (Fab)(2) fragments as affinity protein and different IgGs immobilized to agarose as analytes. The feasibility of this approach for recognition of solid-phase immobilized ligands was documented by screening 50 samples with a 100% hit rate.

  • 18.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, Netherlands.
    Irth, Hubertus
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, Netherlands.
    Tjaden, Ubbo R.
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, Netherlands.
    van der Greef, Jan
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, Netherlands.
    Implementation of affinity solid-phases in continuous-flow biochemical detection1997Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 776, nr 2, s. 169-178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A continuous-flow biochemical detection system is presented which allows the use of solid-phase immobilised affinity proteins. The biochemical detection is performed by mixing analyte with a labelled ligand followed by the addition of solid-phase immobilised affinity protein. After a reaction time of 85 s, free and bound label are separated by means of a hollow fibre module. Quantitation of the free label is performed with a conventional flow-through fluorescence detector. Total assay time amounts to less than 2 min. Biotin was chosen as the model compound using a range of streptavidin-coated solid-phases and an antibody-coated solid-phase as affinity material, and fluorescein–biotin as low-molecular-mass label. The relative standard deviation for twenty repetitive injections was 10.9%. A calibration curve was constructed in the concentration range between 20 and 400 nmol l−1 leading to a correlation coefficient of 0.994. A limit of detection of 8 nmol l−1 was obtained. © 1997 Elsevier Science B.V.

  • 19.
    Lutz, Mareike
    et al.
    Bioanalytical Chemistry, Astra Hässle AB, Mölndal, Sweden.
    Larsson, Marita
    Bioanalytical Chemistry, Astra Hässle AB, Mölndal, Sweden.
    On-Line Microdialysis-Electrospray Mass Spectrometry for Automated Desalting of Small-Volume Peptide Samples1999Ingår i: Chromatographia, ISSN 0009-5893, E-ISSN 1612-1112, Vol. 49, nr Suppl. 1, s. S28-S34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrospray ionization mass spectrometry (ESI-MS) is an important tool for biomolecule analysis. Because the salt content of small-volume peptide samples can hamper analyte ionization, such samples require treatment before ESI-MS.The approach described here consists in interfacing ESI-MS with on-line microdialysis which affords rapid desalting and buffer-exchange. On-line microdialysis was performed by means of a hollow fiber (i.d. 200 μm) coupled to fused silica capillaries. Peptide samples were introduced into the capillary flow system as plugs and transferred to the dialysis cell and the electrospray by means of hydrodynamic pressure. As a result, the ionization efficiency of peptidic analytes was increased and adduct formation with, e.g., sodium, was reduced owing to reduced levels of nonvolatile salts. The feasibility of on-line microdialysis-ESI-MS is shown with a proteolytic digest originating from two-dimensional gel electrophoresis.

  • 20.
    Lutz, Mareike
    et al.
    DMPK & Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Markling, Magnus E.
    DMPK & Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Masimirembwa, Collen M.
    DMPK & Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Monolithic silica rod liquid chromatography with ultraviolet or fluorescence detection for metabolite analysis of cytochrome P450 marker reactions2002Ingår i: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 780, nr 2, s. 205-215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In vitro cytochrome P450 assays are used in metabolism studies in support of early phases of drug discovery to investigate, e.g., metabolic stability, enzyme inhibition and induction by new chemical entities. LC-UV and LC-fluorescence are traditional analytical tools in support of such studies. However, these tools typically comprise different methods of relatively low throughput for the various metabolites of probe reactions. In recent years, LC-MS methods have been developed to increase throughput. Increased throughput can also be achieved by means of modern chromatographic tools in combination with UV and fluorescence detection. This approach is especially suitable when cytochrome P450 isoforms are investigated by means of single probe incubations. Here, an LC-UV/fluorescence system based on a monolithic porous silica column is described for the analysis of metabolites of nine cytochrome P450 marker reactions [phenacetin to paracetamol (CYP1A2), coumarin to 7-hydroxycoumarin (CYP2A6), paclitaxel to 6alpha-hydroxypaclitaxel (CYP2C8), diclofenac to 4-hydroxydiclofenac (CYP2C9), mephenytoin to 4-hydroxymephenytoin (CYP2C19), bufuralol to 1-hydroxybufuralol (CYP2D6), chlorzoxazone to 6-hydroxychlorzoxazone (CYP2E1), midazolam to 1-hydroxymidazolam (CYP3A4), and testosteron to 6beta-hydroxytestosteron (CYP3A4)]. While offering sensitivities and linear ranges comparable to previously reported methods, the set-up described here provides ease of use and increased throughput with maximum cycle times of 4.5 min. © 2002 Elsevier Science B.V. All rights reserved.

  • 21.
    Lutz, Mareike
    et al.
    Division of Analytical Chemistry, Leiden/Amsterdam Ctr. for Drug Res., Leiden University, Leiden, Netherlands.
    Oosterkamp, Aaike J.
    Division of Analytical Chemistry, Leiden/Amsterdam Ctr. for Drug Res., Leiden University, Leiden, Netherlands.
    Irth, Hubertus
    Division of Analytical Chemistry, Leiden/Amsterdam Ctr. for Drug Res., Leiden University, Leiden, Netherlands.
    On-line Coupling of Liquid Chromatography to Biological Assays1997Ingår i: Chimica oggi, ISSN 0392-839X, E-ISSN 1973-8250, Vol. 15, nr 1-2, s. 11-15Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Combining two powerful technologies - liquid chromatography and bioassays results in analytical methodologies which are characterised by high selectivity and sensitivity. In contrast to microtitre-type bioassays, biochemical reactions proceed in a closed, continuous-flow reaction detection system coupled directly to the outlet of the chromatographic separation column. The interaction of substances eluting from the separation column with molecular targets such as antibodies or receptors is monitored directly overcoming tedious fraction collection and manual operations required to prepare the functions for batch immunoassays. important application areas are bioanalysis and drug discovery.

  • 22.
    Marko-Varga, György
    et al.
    Department of Analytical Chemistry, Lund University, Lund, Sweden.
    Burestedt, Elisabeth
    Department of Analytical Chemistry, Lund University, Lund, Sweden.
    Svensson, Carl Johan
    Department of Analytical Chemistry, Lund University, Lund, Sweden.
    Emnéus, Jenny
    Department of Analytical Chemistry, Lund University, Lund, Sweden.
    Gorton, Lo
    Department of Analytical Chemistry, Lund University, Lund, Sweden.
    Ruzgas, Tautgirdas
    Enzyme Chemistry Laboratory, Institute of Biochemistry, Vilnius, Lithuania.
    Lutz, Mareike
    Division of Analytical Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands.
    Unger, Klaus K.
    Institute für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany.
    Effect of HY-Zeolites on the Performance of Tyrosinase-Modified Carbon Paste Electrodes1996Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 8, nr 12, s. 1121-1126Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dependence of electrode response on additive properties in enzyme-modified carbon paste was studied. Four different HY-zeolite powders, dealuminated to different extents and characterized by both Si/Al ratio and hydrophilicity, were used as the carbon paste modifiers. The enzyme tyrosinase used in biosensors for the detection of catechol and other phenolic compounds was chosen as the model system for the construction of a composite carbon paste biosensor incorporating different HY-zeolites as additives. Tyrosinase was trapped on the HY-zeolite particles from a buffer solution, dried and mixed with graphite powder and a pasting oil. It was found that by incorporating HY-zeolites into the carbon paste the heterogeneous reaction rate of catechol redox conversion and the signal response for catechol were increased. In the latter case a higher response was observed for increased hydrophilicity, i.e., decreased Si/Al ratio of the HY-zeolite. The carbon paste/solution interface is considered to be an aqueous/organic phase and the characteristics of the enzyme-modified carbon paste electrode are related to theories, explaining enzymatic catalysis in organic solvents.

  • 23.
    Monaghan, T.
    et al.
    Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Ashby Road, Loughborough, United Kingdom.
    Harding, M. J.
    Department of Chemistry, Loughborough University, Epinal Way, Loughborough, United Kingdom.
    Harris, R. A.
    School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
    Friel, R. J.
    Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Ashby Road, Loughborough, United Kingdom.
    Christie, S. D. R.
    Department of Chemistry, Loughborough University, Epinal Way, Loughborough, United Kingdom.
    Customisable 3D printed microfluidics for integrated analysis and optimisation2016Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 16, nr 17, s. 3362-3373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The formation of smart Lab-on-a-Chip (LOC) devices featuring integrated sensing optics is currently hindered by convoluted and expensive manufacturing procedures. In this work, a series of 3D-printed LOC devices were designed and manufactured via stereolithography (SL) in a matter of hours. The spectroscopic performance of a variety of optical fibre combinations were tested, and the optimum path length for performing Ultraviolet-visible (UV-vis) spectroscopy determined. The information gained in these trials was then used in a reaction optimisation for the formation of carvone semicarbazone. The production of high resolution surface channels (100–500 μm) means that these devices were capable of handling a wide range of concentrations (9 μM–38 mM), and are ideally suited to both analyte detection and process optimisation. This ability to tailor the chip design and its integrated features as a direct result of the reaction being assessed, at such a low time and cost penalty greatly increases the user's ability to optimise both their device and reaction. As a result of the information gained in this investigation, we are able to report the first instance of a 3D-printed LOC device with fully integrated, in-line monitoring capabilities via the use of embedded optical fibres capable of performing UV-vis spectroscopy directly inside micro channels. © The Royal Society of Chemistry 2016.

  • 24.
    Owens, Paul K.
    et al.
    Analytical Chemistry, Pharmaceutical R&D, Astra Hässle AB, Mölndal, Sweden.
    Karlsson, Lars
    Analytical Chemistry, Pharmaceutical R&D, Astra Hässle AB, Mölndal, Sweden.
    Lutz, Mareike
    Bioanalytical Chemistry, Astra Hässle AB, Mölndal, Sweden.
    Andersson, Lars I.
    Bioanalytical Chemistry, Concept Division, Astra Pain Control AB, Södertälje, Sweden.
    Molecular imprinting for bio- and pharmaceutical analysis1999Ingår i: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 18, nr 3, s. 146-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The potential of analytical techniques based on molecular imprinting is reviewed from the viewpoint of bio- and pharmaceutical analysis. A literature study shows that molecularly imprinted polymers (MIPs) have been implemented predominantly in three areas of interest to pharmaceutical industry laboratories. First, in sample preparation, imprinted polymers are used as the sorbent for solid phase extraction purposes. Secondly, MIPs serve as the stationary phase for analytical chromatographic and electrophoretic separations. Thirdly, imprinted polymers are utilised as analyte recognition materials in affinity assays. The advantages of MIPs, e.g., physical robustness, high strength, resistance to elevated temperatures and pressures, and inertness towards acids, bases, metal ions and organic solvents, have been well exploited in a large number of applications. This article focuses on how these benefits may be used for improving the quality of analytical procedures. Some key MIP disadvantages are also highlighted, especially in relation to other analytical techniques. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

  • 25.
    Petersson, Linn
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Hur markegenskaper i produktionsskog påverkas av bök från vildsvin (Sus scrofa) i sydvästra Sverige2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A balance between large-scale and small-scale disturbance is important for maintaining species diversity on landscape level. Wild boar rooting contributes to small-scale disturbance when leaving patches bare of soil. Knowledge is scarce regarding their impact on soil properties in managed spruce forests in south-west Sweden. Therefore, the objective of this study was to determine the effects of wild boar rooting on soil physical and chemical properties, by taking soil samples from the centre, the edge and outside of disturbed patches. Rooting activities significantly increased soil moisture, organic matter, total N and pH but did not affect total P in this study. Areas with high number of disturbed patches had higher soil moisture and organic matter compared to areas with intermediate and few disturbed patches. These new soil characteristics can favour species diversity and ultimately increase productivity in managed forests. The results of this study indicate that wild boar activity contributes to more positive than negative effects in managed spruce forests and focus should therefore lie on preventing wild boar rooting in other areas more sensitive to this disturbance. It is also important to disseminate information and knowledge about the wild boar's positive and negative impact on managed forests in order to better prevent the negative effects and strengthen the positive ones.

  • 26.
    Pobric, Dzenana
    Högskolan i Halmstad, Akademin för lärande, humaniora och samhälle.
    DNA-analys och idemtifikation: En studie om olika metoder för DNA-analys som används för identifikation av mänskliga skelettdelar2018Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 27.
    Račaitytė, Kristina
    et al.
    Kaunas University of Technology, Department of Organic Technology, Kaunas, Lithuania.
    Lutz, Mareike
    Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Mölndal, Sweden.
    Unger, Klaus K.
    Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg Universität, Mainz, Germany.
    Lubda, Dieter
    Merck KGaA, Specialty Laboratory Products, Darmstadt, Germany.
    Boos, Karl Siegfried
    Klinikum Grosshadern, Institut für Klinische Chemie, Munich, Germany.
    Analysis of neuropeptide Y and its metabolites by high-performance liquid chromatography–electrospray ionization mass spectrometry and integrated sample clean-up with a novel restricted-access sulphonic acid cation exchanger2000Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 890, nr 1, s. 135-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel restricted access cation exchanger with sulphonic acid groups at the internal surface was proven to be highly suitable in the sample clean up of peptides on-line coupled to HPLC–electrospray ionization (ESI)-MS. Neuropeptide Y (NPY) and several of its fragments in plasma were subjected to the sample clean-up procedure. The peptides were eluted by a step gradient from the restricted access column, applying 10 mM phosphate buffer pH 3.5 from 5 to 20% (v/v) of acetonitrile with 1 M NaCl and transferred to a Micra ODS II column (33×4.6 mm). The separation of the peptides and their fragments was performed by a linear gradient from 20 to 60% (v/v) acetonitrile in water with 0.1% formic acid and 0.01% trifluoroacetic acid in 4 min at a flow-rate of 0.75 ml/min. An integrated and completely automated system composed of sample clean up–HPLC–ESI-MS was used to analyze real life samples. The sample volumes ranged between 20 and 100 μl. Peaks due to the fragments NPY 1–36, 3–36 and 13–36 in porcine plasma were identified by ESI-MS. The limit of detection was in the 5 nmol/ml range. The total analysis required 21 min and allowed the direct injection of plasma. © 2000 Elsevier Science B.V. All rights

  • 28.
    Skörvald Li, Elin
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Förstudie av blyfria lod till mjuklödning: Utfasning av bly hos ABB i Ludvika2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This study was done for ABB’s work for the phasing out of lead in their soft soldering processes and aims to identify possible lead-free substitutes, due to the RoHs directive and the Reach regulation and the fact that lead is a particularly dangerous chemical. The company’s current solder was defined as SnPb. A literature study has been made where information has been reported regarding lead-free alternatives; SnZn, SnAgCu, SnAg, SnCu, SnBi, SnSb and SnIn. Based on the literature review five lead-free solder were ordered and examined to see if these are possible substitutes for the specific soldering processes. The lead free alternative melting points were measured and the solder technicians ranked the lead-free alternatives in comparison with the reference SnPb to decide which alternative was the most fitting. The literature study and the practical tests show which solder are the best for the company from an economic, social and environmental perspective. The conclusion was that the solder SnCu was the option that fitted the company's soldering processes. To clarify that the solder was a better option than SnPb, the substitution had to be seen from an overall perspective, this could for example, be done by a life cycle analysis.

  • 29.
    Smylie, M. P.
    et al.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Willa, K.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Bao, J. -K
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Ryan, K.
    Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
    Islam, Z.
    Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439, United States.
    Claus, H.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Simsek, Y.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Diao, Zhu
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Rydh, A.
    Department of Physics, Stockholm University, Stockholm, SE-106 91, Sweden.
    Koshelev, A. E.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Kwok, W. -K
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Chung, D. Y.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Kanatzidis, M. G.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Welp, U.
    Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States.
    Anisotropic superconductivity and magnetism in single-crystal RbEuFe4As42018Ingår i: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, nr 10, artikel-id 104503Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the anisotropic superconducting and magnetic properties of single-crystal RbEuFe4As4 using magnetotransport and magnetization measurements. We determine a magnetic ordering temperature of the Eu moments of Tm=15K and a superconducting transition temperature of Tc=36.8K. The superconducting phase diagram is characterized by high upper critical field slopes of -70 and -42 kG/K for in-plane and out-of-plane fields, respectively, and a surprisingly low superconducting anisotropy of Γ=1.7. Ginzburg-Landau parameters of κc∌67 and κab∌108 indicate extreme type-II behavior. These superconducting properties are in line with those commonly seen in optimally doped Fe-based superconductors. In contrast, Eu magnetism is quasi-two dimensional (2D), as evidenced by highly anisotropic in-plane and out-of-plane exchange constants of 0.6 K and <0.04 K. A consequence of the quasi-2D nature of the Eu magnetism are strong magnetic fluctuation effects, a large suppression of the magnetic ordering temperature as compared to the Curie-Weiss temperature, and a kinklike anomaly in the specific heat devoid of any singularity. Magnetization curves reveal a clear magnetic easy-plane anisotropy with in-plane and out-of-plane saturation fields of 2 and 4 kG. © 2018 American Physical Society.

  • 30.
    Unnestam, Evelina
    et al.
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    Andersson, Emma
    Högskolan i Halmstad, Sektionen för lärarutbildning (LUT).
    Hur kan intresse utvecklas för fysik och kemi i grundskolans tidigare år: - En analys av tidigare forskning2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I den senaste PISA undersökningen från 2012 testades elevernas kunskaper i matematik, läsning och naturvetenskap hos femtonåringar runt om i landet. Sverige var det land som försämrat sina resultat mest av alla deltagande länder inom samtliga områden. Detta tyder på att något måste göras. Vi har studerat hur man kan väcka intresse för ämnena fysik och kemi inom naturvetenskapen. Detta för att öka de naturvetenskapliga kunskaperna hos eleverna i skolan. Vi har använt oss av en litteraturstudie där vi samlat in och kritiskt granskat tidigare forskning för att besvara våra forskningsfrågor. Dessa är Kan läraren med ett annorlunda innehåll och arbetssätt skapa ett större intresse för naturvetenskapen och på vilka sätt? och Vad ska läraren utgå från och i vilka lärmiljöer är det lättast att fånga elevernas nyfikenhet kring naturvetenskapen? Det som ökar intresset för naturvetenskap är att läraren ska bygga undervisningen på elevernas intresse, att undervisningen ska vara vardagsanknuten och arbetas med i teman i ämnets naturliga miljöer detta betyder att undervisningen måste flyttas utanför den traditionella klassrumsmiljön. Vi rekommenderar att fortsatt forskning skapar ett konkret material som följer läroplanen och är grundat på forskning kring intresseväckande naturvetenskap för grundskolans tidigare år.

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