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  • 1.
    Abbas, Asad
    Karlstad University, Faculty of Technology and Science.
    Flow sheeting software as a tool when teaching Chemical Engineering2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to design different chemical processes by using flow sheeting software and to show the usefulness of flow sheeting software as an educational tool. The industries studied are hydrogen, sulfur, nitric acid and ethylene glycol production and a model of drying technique is also included. Firstly, there is an introduction of chemcad as a tool when teaching chemical processes and explanation of each industry which is selected to design. Various production methods for each product are explained and the advantages of the method which is selected to design the chemical flow sheet are discussed. There is also an introduction of the industrial uses of these products formed in Pakistan. The models are designed by using different reactors, heat exchangers, pumps, mixers, boilers and distillation column. The models are designed based upon data taken from literature. The temperature and pressure values are in good agreement with data mentioned in literature. The material balance shown by Chemcad is quite different from data mentioned in literature. Some changes in thermodynamic properties of components in Chemcad software might lead to better agreement between the Chemcad models and literature data. It is not possible to use catalyst in Chemcad to increase the rate of reaction. One possibility is to introduce new components. It is good to use equilibrium reactor when it is required to convert the given component into respective products provided that either conversion of the equilibrium constant are known. It is difficult to study the hidden critical assumptions built in the model when using Gibb’s reactor, as a result there is a deviation in behavior from the system described in the literature. Gibb’s reactor is useful when neither conversion ratio nor equilibrium constant is known.

  • 2.
    Abbas, Azhar
    Karlstad University, Faculty of Technology and Science.
    GPIB- kommunikation och PID reglering med LabVIEW2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    LabVIEW ger en snabb och enkel tillgång till att styra instrument och en mycket stor databas med drivrutiner för DAQ-kort och olika datorgränssnitt (GPIB, serie, osv.).

    Många instrument och datorer kan anslutas till GPIB-bussen.  Detta kan ge en praktisk modell för utveckling av instrumentets styrprogram i LabVIEW med hjälp av GPIB-gränssnittet.

    Ett program i LabVIEW 8.2 med hjälp av GPIB-bussen kan kopplas till t.ex. multimetern (HP-34401A) för att mäta och visa multimeters noggrannhet. Men på grund av fel i drivrutiner för GPIB-gränssnittet kunde jag inte köra programmet med GPIB-bussen.

    Genom att använda LabVIEW 8.2 med hjälp av DAQ-kort kan en PID-regleringsalgoritm simuleras. PID konstrueras med virtuella instrument som innehåller alla nödvändiga komponenter och utrustning som krävs för att reglera någon linjär eller olinjär process exempelvis att nivåreglera två tankar i serie. Här stöter vi på alla de grundläggande regulatorer och får möjlighet att bygga PID med LabVIEW på ett enkelt sätt. Det finns två metoder för att bygga PID. Den första är med matematiska funktioner och den andra är med ’’Simulations functions control’’. Arbetet visar att bägge metoderna fungerar bra för att lösa uppgiften jämfört med färdiga PID-controls på LabVIEW.

  • 3. Abdel-Rehim, M.
    et al.
    Altun, Zeki
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    New trend in sample preparation: On-line microextraction in packed syringe (MEPS) for LC and GC applications, Part II, Determination of ropivacaine and its metabolites in human plasma samples using MEPS-LC-MS-MS2004In: J. Mass Spectr., 39 (2004) 1488-1493Article in journal (Refereed)
  • 4. Abdel-Rehim, M.
    et al.
    Carlsson, Gunilla
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Bielenstein, M.
    Arvidsson, T.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Evaluation of Solid-Phase microextraction (SPME) for Study of the protein Binding in Human Plasma Samples,2000In: J. Chromatogr. Sci., 38 (2000) 458-464Article in journal (Refereed)
  • 5. Abdel-Rehim, M.
    et al.
    Hassan, Z.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Hassan, M.
    Determination of Busulphan in plasma samples by gas chromatography-mass spectrometry (GC-MS) using on-line derivatization utilizing solid-phase microextraction (SPME)2003In: J. Therapeutic Drug Monitoring, 25 (2003) 400-406Article in journal (Refereed)
  • 6. Abdel-Rehim, M.
    et al.
    Skansen, P.
    Vita, M.
    Hassan, Z.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Hassan, M.
    Microextraction in packed syringe / liquid chromatography /electrospray tandem mass spectrometry (MEPS/LC/MS/MS) for quantification of olomoucine in human plasma samples2005In: Anal.Chim. Acta., 539 (2005) 35-39Article in journal (Refereed)
  • 7.
    Abdel-Rehim, Mohamed
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. AstraZeneca R&D Sodertalje, Global DMPK, SE-15185 Sodertalje, Sweden.;Stockholm Univ, Dept Analyt Chem, SE-10691 Stockholm, Sweden.;Karlstad Univ, Dept Chem & Biomed Sci, Fac Sci & Technol, SE-65188 Karlstad, Sweden..
    Microextraction by packed sorbent (MEPS): A tutorial2011In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 701, no 2, 119-128 p.Article in journal (Refereed)
    Abstract [en]

    This tutorial provides an overview on a new technique for sample preparation, microextraction by packed sorbent (MEPS). Not only the automation process by MEPS is the advantage but also the much smaller volumes of the samples, solvents and dead volumes in the system. Other significant advantages such as the speed and the simplicity of the sample preparation process are provided. In this tutorial the main concepts of MEPS will be elucidated. Different practical aspects in MEPS are addressed. The factors affecting MEPS performance will be discussed. The application of MEPS in clinical and pre-clinical studies for quantification of drugs and metabolites in blood, plasma and urine will be provided. A comparison between MEPS and other extraction techniques such as SPE, LLE, SPME and SBSE will be discussed. (C) 2011 Elsevier B.V. All rights reserved.

  • 8.
    Abdel-Rehim, Mohamed
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. AstraZeneca R&D Sodertalje, Global DMPK, Sodertalje, Sweden.;Karlstad Univ, Fac Sci & Technol, Dept Chem & Biomed Sci, Karlstad, Sweden..
    On-Line Whole Blood Analysis Using Microextraction by Packed Sorbent and LC-MS-MS2011In: LC GC North America, ISSN 1527-5949, E-ISSN 1939-1889, Vol. 29, no 7, 612-618 p.Article in journal (Refereed)
    Abstract [en]

    Microextraction by packed sorbent (MEPS) is a new technique for sample preparation that can be connected on-line with liquid chromatography (LC) or gas chromatography (GC) systems without any modifications. This article describes the use of MEPS in clinical and preclinical studies to quantify different drugs in whole blood samples. MEPS was used to determine cyclophosphamide in mouse blood from preclinical g studies using 20 mu L of blood samples. The interday accuracies and 0 precisions ranged from 107-109% and from 2.0-7.0%, respectively. The determination of four immunosuppressive drugs in human blood by MEPS and liquid chromatography-mass spectrometry (LC-MS) is described. The method showed a good selectivity and sensitivity. The calibration curves for everolimus, sirolimus, and tacrolimus ranged from 0.5 to 50 ng/mL and for cyclosporine from 3.0 to 1500 ng/mL. Intraday precisions for the studied immunosuppressive drugs were 2.0-11.7% and interday precision ranged from 5.1 to 13.7% (CV).

  • 9.
    Abdel-Rehim, Mohamed
    et al.
    AstraZeneca R&D Södertälje, Södertälje, Sweden.
    Andersson, L.I.
    AstraZeneca R&D Södertälje, Södertälje, Sweden.
    Altun, Zeki
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Microextraction in Packed Syringe Online with Liquid Chromatography-Tandem Mass Spectrometry: Molecularly imprinted polymer as packing material for MEPS in selective extraction of ropivacaine from plasma2006In: Journal of Liquid Chromatography & Related Technologies, ISSN 1082-6076, E-ISSN 1520-572X, Vol. 29, no 12, 1725-1736 p.Article in journal (Refereed)
    Abstract [en]

    The excellent performance of a new sample preparation method, microextraction in packed syringe (MEPS), was recently illustrated by online LC‐MS and GS‐MS assays of local anaesthetics in plasma samples. In the method, approximately 1 mg of solid packing material was inserted into a syringe (100–250 µL) as a plug. Sample preparation took place on the packed bed. The new method was easy to use, fully automated, of low cost, and rapid in comparison with previously used methods. This paper presents the use of molecularly imprinted polymers (MIPs) as packing material for higher extraction selectivity. Development and validation of a method for MIP‐MEPS online with LC‐MS‐MS using ropivacaine in plasma as model compound were investigated. A bupivacaine imprinted polymer was used. The method was validated and the standard curves were evaluated by means of quadratic regression and weighted by inverse of the concentration: 1/x for the calibration range 2–2000 nM. The applied polymer could be used more than 100 times before the syringe was discarded. The extraction recovery was 60%. The results showed high correlation coefficients (R 2 >0.999) for all runs. The accuracy, given as a percentage deviation from the nominal concentration values, ranged from -6% to 3%. The precision, given as the relative standard deviation, at three different concentrations (QC samples) was consistently about 3% to 10%. The limit of quantification was 2 nM.

  • 10. Abdel-Rehim, Mohamed
    et al.
    Dahlgren, Marie
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Quantification of ropivacaine and its major metabolites in human urine samples utilizing microextraction in packed syringe automated with liquid chromatography-tandem mass spectrometry (MEPS-LC-MS-MS)2006In: J. Sep. Sci., 29 (2006) 1658-1661Article in journal (Refereed)
  • 11. Abdel-Rehim, Mohamed
    et al.
    Dahlgren, Marie
    Claude, Saturnin
    Tabacchi, Raphael
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Microextraction in packed syringe (MEPS) utilizing methylcyanopropyl silarylene as coating polymer for extraction of drugs in biological samples,2006In: J. Liq. Chromatogr. & Relat. Technol., 29 (2006) No. 17, 2537-2544Article in journal (Refereed)
  • 12.
    Abdulhadi, Sami
    Karlstad University, Faculty of Technology and Science.
    ARM i inbyggt system: med prototyp2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Embedded systems has become more and more common in today's society. The embedded systems are included in almost everything today, from various vehicles to children's toys.

    Today's technology means that yesterday's solutions can be realised on a fraction of the area. More and more become surface mounted with smaller and more complex circuits. This is not always an advantage for the developers when assembling and soldering prototype circuit boards become a more difficult and/or an expensive process.

    The goal is to create an embedded system with an ARM-processor. The system will consist of USB-OTG, ethernet, various memory like FRAM and microSD and a display with touchscreen for user interface. The project includes everything from choice of components to test and verification with program code.

    The time was too short to include all the parts that was planned. The result of the project was a prototype card and two small program sequences, one that blinks the two light diodes on the card and one that writes a picture on the display.

    This embedded system is intended for evaluating ARM-processors by Mikrododakt AB.

  • 13. Acedo, L.
    et al.
    Santos, A.
    Bobylev, Alexander
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    On the derivation of a high-velocity tail from the Boltzmann-Fokker-Planck equation for shear flow2002In: J. Statist. Phys, Vol. 109:5-6Article in journal (Refereed)
  • 14.
    Adolfsson, Oscar
    et al.
    Karlstad University, Faculty of Technology and Science.
    Blomqvist, Marcus
    Karlstad University, Faculty of Technology and Science.
    Vägghängd duschpall: Utveckling av duschpall för Etac Supply Center AB2010Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This degree project has been carried out by Oscar Adolfsson and Marcus Blomqvist, during the spring of 2010, both studying to become Bachelor of Science in Innovation and Design Engineering, at Karlstad University. The degree project includes 22,5 credits.The work is done on behalf of Etac Supply Center AB in Anderstorp. Etac is a company developing and manufacturing home health care products, with operation in Sweden, Norway, Denmark, England and Germany, and with sales worldwide. Bo Lindqvist, R & D manager has been the contact person at Etac.During the project the students has had a workplace at Semcon Caran AB in Karlstad. Semcon has also been helpful as a sounding board.The objective of the work has been developing a new, wall mounted shower chair, assigned for persons with difficulty to stand up while showering.Etacs requirement of the shower chair is that it should be able to support a user with a weight of 100 kg, the chair shouldn’t have any outrigger, optional should be armrests and backrest. The seat should be mountable in existing bathrooms, and act as a complement for the current shower seats sold by Etac. It’s very important that the result is good looking, and appealing to new target groups.In the start of this project, the students have been carrying through a benchmarking, mainly at the NordBygg fair in Stockholm. The students have been agreeing about the lack of products with both functionality and aesthetic appealing qualities.The result is adjusted to fit the most common wall constructions in Sweden.Four concepts have been developed, and among these four, one is the final result. The final result consists of two aluminium wall rails and a plastic seat. A plastic backrest, and armrest in both plastic and stainless steel are optional.During the work, the specifications on products like these, from the Swedish institute of assistive technology, concerning strength and risks of pinching has been observed.The project has resulted in CAD-files and a model in scale 1:3, manufactured by Etac.

  • 15.
    Aeyadi, Amin
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Formation of protective lubricious oxide layers on the surface of nitrogen alloyed steels in self-mated sliding2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 16.
    Ahl, Daniel
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analysis of how different mesh functions influence the result in CFD-simulation of a marine propeller:  2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 17.
    Ahlgren, Joakim
    et al.
    Karlstad University, Faculty of Technology and Science.
    Lidström, Joakim
    Karlstad University, Faculty of Technology and Science.
    Gastromax Duo: Ett kompakt rivjärn för den moderna hemmakocken2010Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    ”Gastromax Duo” is a degree project for the Innovation and Design Engineering program at Karlstad University. Joakim Ahlgren and Joakim Lidström have independently carried out the project during Spring Term 2010. The degree project extends 22,5 ECTS credits.

    The assigners for this project are Peter Ottosson and Jonas Eriksson at Sveico AB in Gnosjö, Sweden. Peter Johansson is the project supervisor at Sveico AB and Monica Jacobsson is the academic supervisor at Karlstad University. The examiner at Karlstad University is Lennart Wihk, who has also supported the project team during the design process.

    Sveico AB is located in Gnosjö, Sweden and manufactures kitchen utensils and other kitchen accessories. In the Sveico AB product portfolio resides the Gastromax series of kitchen tools for the ”home chef”. The lack of a foldable grater within the Gastromax series was noticed by the Sveico AB management, which brought about this project.

    The largest part of this project was a very thorough pre-study phase, where the project team mapped out the needs and wishes of the users, along with research about the market of the product. The pre-study consists of interviews with consumers, professional users and representatives of commerce, along with user studies.

    During the product development process, a number of idea generation methods has been used, both internally in the project team and externally with uninitiated individuals. During the subsequent concept generation phase, emphasis was put on the development of physical models, used to evaluate ideas and solutions.

    Out of the 19 concepts that were developed during the concept generation phase, six was chosen through a set of systematic evaluation routines. These six concepts were presented to the assigners that in turn chose two of the concepts for the project team to develop further. These two concepts was then combined and transformed into the final product proposal.

    The final, detailed solution is surrounded with secrecy, but three key concepts in the final foldable grater can be officially stated:

    • A long grating surface
    • Adjustable work angle
    • Two grating surfaces: one fine and one coarse

    The final result of the project is a product description of the grater, with a proposal of a general design, a mechanical solution of the adjustability aspect and a suggestion of materials for the different product components.

  • 18.
    Ahmed, Faisal Mahmood
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Estimated Droop Control for Parallel Connected Voltage Source Inverters: Stability Enhancement2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Renewable Energy Sources (RES) are considered as the replacement of conventionalenergy sources. These RES can use wind energy, solar light, bio waste and can alsobe in the form of small hydro power units. These RES has very poor power qualityand contains voltage uctuations and variable frequency. These factors make RES astability risk for the main utility grid. As a solution, currently inverters with dierentdesign techniques are being used as an interface between RES and main utility grid. Thecurrent study proposed a new technique "estimated droop control" for inverter design.The conventional droop control technique which was already used in inverter design, hasdiculty in synchronizing parallel connected inverters with dierent droop gains and lineimpedances. The proposed "estimated droop control" does not use any predened droopvalues for inverters and all inverters are responsible for the estimation of their own droopvalues with respect to their output power. Therefore, inverters are not bound to usesame and static droop values which are considered as a vital communication link. Theproposed design methodology has made inverters independent from this only virtual linkof communication due to which the reliability of a system has increased. The proposeddesign technique has given very good results in a simulation run. When the Simulinkmodel was run in parallel connected inverter with dierent line impedances, it was asuccess as both inverters started operating with same droop values as they were sharingan equal load. The most important test was with dierent line impedances because inconventional droop control it is dicult for inverters to keep their synchronism withdierent line impedances and an unequal load sharing make inverters to deviate fromtheir nominal values and to generate dierent tracking signals for each set. This problemhas been successfully solved with estimated droop control as in this method each inverterset its droop gains according to its output power, which helps an inverter to operate atnominal values with dierent droop gains and line impedance.

  • 19.
    Ahmed, Naeem
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Cooperative Spectrum Sensing for Cognitive Radio Networks2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The great developments in the field of wireless communications that has been accelerated by the commercial need for better services has led to the application of wireless systems in many fields of life. The effect of wireless technology is much widened, like for safety applications, home automation, smart grid control, medical wearable, embedded wireless devices, entertainment systems etc.

    Direct and indirect surveillance of spectrum treatment has acknowledged the sequential and spatial accessibility of spectrum inside allocated frequency bands. This implies that spectrum deficiency is becoming a main problem. Therefore, spectrum deficiency problem arises here in terms of that most of the licensed primary users are not using their spectrum due to any reason of either geographical variation or temporal basis, and lot of allotted spectrum is unused and under-utilized. Moreover, along with spectrum deficiency problem, other issues are also linked like interference caused by secondary unlicensed users to primary licensed users while sharing the work load among each others, and problem of vacating the spectrum band in less fewer time frames after primary users detection.

    Cognitive networks assure to tackle these spectrum deficiency and other associated problems by accommodating secondary (unlicensed) users, in the spectrum region which is under-utilized. Spectrum Sensing is the prime motivation for cognitive radio and ensures that secondary (unlicensed) users do not propose unbearable levels of interference to primary (licensed) users.

    Cooperative Spectrum Sensing methodologies are still an open window of research. This work is related to cope up the problem of spectrum deficiency and associated problems, by developing an approach for establishment of grouping/clustering between secondary users in a cooperative spectral environment. This approach ensures that members within a group are highly correlated. As a result, the workload on each sensing node within a group is reduced. The effectiveness of this approach depends upon the accuracy of fused decision related to the presence or absence of primary (licensed) user at a particular band (50MHZ to 100MHZ). This approach also depends on the factor that time taken in sensing the primary (licensed) users should be less enough so that decision in vacating the band by the Cognitive Radio secondary users could be taken in fewer time frames. This latter metric is known to be ‘agility’, which eventually comes with the outcome of minimum interference to primary users via their early recognition.

  • 20.
    Ahmed, Umair
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Racing Driver Model in Dymola Vehicle Dynamics Library (VDL): Steering Controller Design2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Racing drivers always want to traverse path at vehicle’s maximum performance limits while keeping the vehicle at its ideal trajectory. The main objective of this report is to elaborate strategy for the path following problem in which driver has to follow the predefined 2D roads. New steering controller design for closed loop racing driver model in Dymola vehicle dynamics library is developed. The methodology proposed by Sharp et al. [2] is followed with the optimal velocity profile that tries to mimic the actions of the real drivers in real time scenarios. Vehicle handling limits i.e. longitudinal and lateral limits are defined before simulation. While travelling in the neighbourhood of optimal velocity on the straight road as well as during the curves, the performance of the steering controller is tested by conducting the test on J turn, Clothoid, Extended chicane and the closing curve path and also tested during the different environment effects e.g. when there is a side wind affecting the vehicle. Performance of existing and new steering controllers discussed and compared in result chapter. It is ensured that the drawbacks in the existing steering controller are eliminated by using the proposed methodology in new implemented steering controller.

    Key Words: Driver Model, Steering Controller, Path following, Velocity profile

  • 21. Aldaeus, Fredrik
    et al.
    Johansson, Lars-Erik
    Jönsson, Mats
    Jonsson, Gunnar
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Lindberg, Ulf
    Roeraade, Johan
    Hamp, Sven
    Escherichia Coli Behavior in an Open Dielectrophoretic Microsystem2004Conference paper (Other (popular science, discussion, etc.))
  • 22. Aldaeus, Fredrik
    et al.
    Yuan, Lin
    Jönsson, Mats
    Johansson, Lars-Erik
    Jonsson, Gunnar
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Roeraade, Johan
    Amberg, Gustav
    Dielectrophoresis of Living Cells - New Concepts and Challenges2005Conference paper (Other (popular science, discussion, etc.))
  • 23.
    Aldaz, J. M.
    et al.
    Univ Autonoma Madrid, ICMAT, E-28049 Madrid, Spain.;Univ Autonoma Madrid, Dept Matemat, E-28049 Madrid, Spain..
    Barza, Sorina
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    Fujii, M.
    Osaka Kyoiku Univ, Dept Math, Kashiwara, Osaka 5828582, Japan..
    Moslehian, Mohammad Sal
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science. Karlstad Univ, Dept Math & Comp Sci, SE-65188 Karlstad, Sweden.;Ferdowsi Univ Mashhad, Dept Pure Math, CEAAS, Mashhad 91775, Iran..
    Advances in Operator Cauchy-Schwarz Inequalities and their Reverses2015In: Annals of Functional Analysis, ISSN 2008-8752, E-ISSN 2008-8752, Vol. 6, no 3, 275-295 p.Article in journal (Refereed)
    Abstract [en]

    The Cauchy-Schwarz (C-S) inequality is one of the most famous inequalities in mathematics. In this survey article, we first give a brief history of the inequality. Afterward, we present the C-S inequality for inner product spaces. Focusing on operator inequalities, we then review some significant recent developments of the C-S inequality and its reverses for Hilbert space operators and elements of Hilbert C*-modules. In particular, we pay special attention to an operator Wielandt inequality.

  • 24.
    Alfredsson, Lottie
    et al.
    Karlstad University, Faculty of Technology and Science.
    Christenson, Sara
    Karlstad University, Faculty of Technology and Science.
    Supplier Selection & Quality Expectations: Development of a Simple Supplier Evaluation Tool in a Norwegian Ventilation Systems Company2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In today’s competitive market, survival and response to customer needs and

    expectations are enabled through high-quality products for low costs – quality

    products provided by suppliers fulfilling today’s quality-requirements for a low

    price. Companies have until recent years selected suppliers only according to a

    pricing structure, leaving other criteria’s, such as quality, behind.

    The purpose of this master thesis is therefore to investigate quality aspects that

    must be considered from a supplier evaluation perspective and design a simple

    evaluation tool for first-time supplier selections. Both new and existing

    suppliers will be tested with the tool according to information given during a

    case study made at Flexit AS, a Norwegian ventilation-systems company

    looking to introduce a structured approach for selecting suppliers.

    Through an extensive literature- and empirical study, where a survey, of which

    evaluation criteria’s to be included in the evaluation tool, was conducted

    together with several both semi-structured and unstructured interviews, a

    foundation for the design of the tool was presented.

    Quality management systems and quality performance measurements, such as

    rejection rate and delivery precision, are considered as fundamental aspects to

    consider when assessing a supplier. Acceptance levels of approval are set

    according to in-house objectives. If any evaluation tool including quality

    should be usable, an in-house quality system must therefore first be

    implemented by the in-house company – a notable improvement

    recommended to the case company.

    The design of the tool given from the thesis provides the evaluator with an

    opportunity to visualize and compare existing suppliers according to five

    criteria’s including cost, together with an additional spreadsheet for evaluation

    of new suppliers put forward as a foundation and an indicator if new suppliers

    are considering quality on a basic level.

  • 25.
    Alfredsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science.
    Haeffner, Fredric
    Karlstad University, Faculty of Technology and Science.
    Åtgärdsförslag för erosionsskador i Kölaälv2006Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
  • 26.
    Algervik, Robert
    Karlstad University, Faculty of Technology and Science, Avdelningen för matematik.
    Embedding Theorems for Mixed Norm Spaces and Applications2010Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis is devoted to the study of mixed norm spaces that arise in connection with embeddings of Sobolev and Besov type spaces. We study different structural, integrability, and smoothness properties of functions satisfying certain mixed norm conditions. Conditions of this type are determined by the behaviour of linear sections of functions. The work in this direction originates in a paper due to Gagliardo (1958), and was further developed by Fournier (1988), by Blei and Fournier (1989), and by Kolyada (2005).

    Here we continue these studies. We obtain some refinements of known embeddings for certain mixed norm spaces introduced by Gagliardo, and we study general properties of these spaces. In connection with these results, we consider a scale of intermediate mixed norm spaces, and prove intrinsic embeddings in this scale.

    We also consider more general, fully anisotropic, mixed norm spaces. Our main theorem states an embedding of these spaces to Lorentz spaces. Applying this result, we obtain sharp embedding theorems for anisotropic Sobolev-Besov spaces, and anisotropic fractional Sobolev spaces. The methods used are based on non-increasing rearrangements, and on estimates of sections of functions and sections of sets. We also study limiting relations between embeddings of spaces of different type. More exactly, mixed norm estimates enable us to get embedding constants with sharp asymptotic behaviour. This gives an extension of the results obtained for isotropic Besov spaces by Bourgain, Brezis, and Mironescu, and for anisotropic Besov spaces by Kolyada.

    We study also some basic properties (in particular the approximation properties) of special weak type spaces that play an important role in the construction of mixed norm spaces, and in the description of Sobolev type embeddings.

    In the last chapter, we study mixed norm spaces consisting of functions that have smooth sections. We prove embeddings of these spaces to Lorentz spaces. From this result, known properties of Sobolev-Liouville spaces follow.

  • 27.
    Algervik, Robert
    Karlstad University, Faculty of Technology and Science, Avdelningen för matematik.
    Embedding Theorems for Mixed Norm Spaces and Applications2008Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    This thesis is devoted to the study of mixed norm spaces that arise in connection with embeddings of Sobolev and Besov type spaces. The work in this direction originates in a paper due to Gagliardo (1958), and was continued by Fournier (1988) and by Kolyada (2005).

    We consider fully anisotropic mixed norm spaces. Our main theorem states an embedding of these spaces into Lorentz spaces. Applying this result, we obtain sharp embedding theorems for anisotropic fractional Sobolev spaces and anisotropic Sobolev-Besov spaces. The methods used are based on non-increasing rearrangements and on estimates of sections of functions and sections of sets. We also study limiting relations between embeddings of spaces of different type. More exactly, mixed norm estimates enable us to get embedding constants with sharp asymptotic behaviour. This gives an extension of the results obtained for isotropic Besov spaces $B_p^\alpha$ by Bourgain, Brezis, and Mironescu, and for Besov spaces $B^{\alpha_1,\dots,\alpha_n}_p$ by Kolyada.

    We study also some basic properties (in particular the approximation properties) of special weak type spaces that play an important role in the construction of mixed norm spaces and in the description of Sobolev type embeddings.

  • 28.
    Algervik, Robert
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    Kolyada, Viktor
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    On Fournier-Gagliardo mixed norm spaces2011In: Annales Academiae Scientiarum Fennicae Mathematica, ISSN 1239-629X, Vol. 36, 493-508 p.Article in journal (Refereed)
    Abstract [en]

    We study mixed norm spaces

    V (Rn)

    that arise in connection with embeddings of

    Sobolev spaces

    W

    1

    1

    (Rn). We prove embeddings of V (Rn)

    into Lorentz type spaces defined in terms

    of iterative rearrangements. Basing on these results, we introduce the scale of mixed norm spaces

    V

    p

    (Rn). We prove that V ½ V p

    and we discuss some questions related to this embedding.

  • 29.
    Alho, Artur
    et al.
    Technical University of Lisbon, Portugal.
    Uggla, Claes
    Karlstad University, Faculty of Technology and Science.
    Global dynamics and inflationary center manifold and slow-roll approximants2015In: Journal of Mathematical Physics, ISSN 0022-2488, E-ISSN 1089-7658, Vol. 56, no 1, 012502- p.Article in journal (Refereed)
    Abstract [en]

    We consider the familiar problem of a minimally coupled scalar field with quadratic potential in flat Friedmann-Lemaître-Robertson-Walker cosmology to illustrate a number of techniques and tools, which can be applied to a wide range of scalar field potentials and problems in, e.g., modified gravity. We present a global and regular dynamical systems description that yields a global understanding of the solution space, including asymptotic features. We introduce dynamical systems techniques such as center manifold expansions and use Padé approximants to obtain improved approximations for the “attractor solution” at early times. We also show that future asymptotic behavior is associated with a limit cycle, which shows that manifest self-similarity is asymptotically broken toward the future and gives approximate expressions for this behavior. We then combine these results to obtain global approximations for the attractor solution, which, e.g., might be used in the context of global measures. In addition, we elucidate the connection between slow-roll based approximations and the attractor solution, and compare these approximations with the center manifold based approximants.

  • 30. Ali, A
    et al.
    Hoagg, J. B
    Mossberg, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Bernstein, D. S
    Growing window recursive quadratic optimization with variable regularization2010Conference paper (Refereed)
  • 31. Almgren, M
    et al.
    Alsins, J
    Mukhtar, E
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Diffusion-Controlled Fluorescence Quenching in Micelles1989In: Reactions in Compartmentalized Liquids; Knoche W and Shomacker R (eds), Springer-Verlag, Berlin Heidelberg (1989), 61-68, 1989Chapter in book (Refereed)
  • 32. Almgren, M.
    et al.
    Alsins, J.
    Mukhtar, E.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Fluorescence Quenching Dynamics in Rodlike Micelles1988In: J. Phys. Chem., 1988, 92, 4479-4483Article in journal (Refereed)
  • 33. Almgren, M.
    et al.
    Alsins, J.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Fluorescence Decay Studies of Structures and Dynamics in Ionic Micellar Solutions1988In: Ordering and Organization in Ionic Solutions, World Scientific Publishing Co Ltd, Singapore, 1988, 225-232, 1988Chapter in book (Refereed)
  • 34. Almgren, M
    et al.
    Alsins, J
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Mukhtar, E
    The micellar sphere-to-rod transition in CTAC-NaClO3. A fluorescence quenching study1988In: Progr. Colloid Polym. Sci., 1988, 76, 68-74Article in journal (Refereed)
  • 35. Almgren, M.
    et al.
    Hansson, P.
    Mukhtar, E.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Aggregation of Alkyltrimethylammonium Surfactants in Aqueous Poly(styrenesulfonate) Solutions1992In: Langmuir, 1992, 8, 2405-2412Article in journal (Refereed)
  • 36. Almgren, M.
    et al.
    Löfroth, J-E
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Fluorescence Decay Kinetics in Monodisperse Confinements with Exchange of Probes and Quenchers1986In: J. Phys. Chem., 1986, 90, 4431-4437Article in journal (Refereed)
  • 37. Almgren, M.
    et al.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Lindblad, C.
    Li, P.
    Stilbs, P.
    Bahadur, P.
    Aggregation of Poly(ethyelene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Copolymers in the Presence of Sodium Dodecyl Sulfate in Aqueous Solution1991In: J. Phys. Chem., 1991, 95, 5677-5684Article in journal (Refereed)
  • 38. Almgren, M
    et al.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Swarup, S
    Löfroth, J-E
    Structure and Transport in the Microemulsion Phase of the System Triton X-100-Toluene-Water1986In: Langmuir, 1986, 2, 432-438Article in journal (Refereed)
  • 39.
    Almlöf Ambjörnsson, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Extended Mercerization Prior to Carboxymethyl Cellulose Preparation2011Conference paper (Other (popular science, discussion, etc.))
  • 40.
    Almlöf Ambjörnsson, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Enzyme treatment of dissolving pulps as a way to improve the following dissolution of the fibres2012Conference paper (Other academic)
  • 41.
    Almlöf Ambjörnsson, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Jardeby, Kristina
    Borregaard Chemcell, Sarpsborg, Norge.
    Kreutz, Björn
    Borregaard Chemcell, Sarpsborg, Norge.
    The influence of mercerization on the degree of substitution in carboxymethyl cellulose2009Conference paper (Other (popular science, discussion, etc.))
  • 42.
    Almlöf Ambjörnsson, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Schenzel, Karla
    Marthin-Luther University Halle-Wittenberg.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Characterization of CMC by NIR FT Raman spectroscopy2012Conference paper (Other (popular science, discussion, etc.))
  • 43.
    Almlöf, Heléne
    Karlstad University, Faculty of Technology and Science, Avdelningen för kemiteknik.
    Extended Mercerization Prior to Carboxymethyl Cellulose Preparation2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Carboxymethyl cellulose (CMC) is produced commercially in a two-stage process consisting of a mercerization stage, where the pulp is treated with alkali in a water alcohol solution, followed by an etherification stage in which monochloroacetic acid is added to the pulp slurry. In this thesis an extended mercerization stage of a spruce ether pulp was investigated where the parameters studied were the ratio of cellulose I and II, concentration of alkali, temperature and retention time. The influence of the mercerization stage conditions on the etherification stage, were evaluated as the degree of substitution (DS) of the resulting CMC and the filterability of CMC dissolved in water at a concentration of 1%. The DS results suggested that the NaOH concentration in the mercerization stage was the most important of the parameters studied. When the NaOH concentration in the mercerization step was low (9%), a high cellulose II content in the pulp used was found to have no negative impact on the DS of the resulting CMC compared with pulps with only cellulose I. However, when the NaOH concentration was high (27.5%), pulps with high content of cellulose II showed a lower reactivity than those with only cellulose I with respect to the DS of the CMC obtained after a given charge of NaMCA.

    The results obtained from the filtration ability study of CMC water solutions suggested that both the amount of cellulose II in the original pulp and the temperature had a negative influence on the filtration ability whereas the NaOH concentration in the mercerization stage had a positive influence. The filtration ability was assumed to be influenced highly by the presence of poorly reacted cellulose segments. A retention time between 1-48 h in the mercerization stage had no effect on either the DS or the filtration ability of the CMC.

    Using NIR FT Raman spectroscopy molecular structures of CMC and its gel fraction were analyzed with respect to the conditions used in the extended mercerization stage. Here it was found that the alkaline concentration had a very strong influence on the following etherification reaction. FT Raman spectra of CMC samples and their gel fractions prepared with low NaOH concentrations (9%) in the mercerization stage indicated an incomplete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Low average DS values of the CMC, i.e. between 0.42 and 0.50, were yielded. Such CMC dissolved in water caused very thick and semi solid gum-like gels, probably due to an uneven distribution of substituting groups along the cellulose backbone. FT Raman spectra of CMC mercerized with alkaline concentrations at 18.25 and 27.5% in the mercerization stage indicated, however, that all of the cellulose molecules were totally transferred to CMC of high DS, i.e. between 0.88 and 1.05. When dissolved in water such CMC caused gels when they were prepared from ether pulp with a high fraction of cellulose II.

  • 44.
    Almlöf, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Basta, Jiri
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Guo, Sanchuan
    Heijnesson-Hulten, Anette
    The Effect of Stock Storage on The Quality of Bamboo Kraft Pulp2010In: O PAPEL, ISSN 0031-1057, Vol. 72, no 6, 43-53 p.Article in journal (Refereed)
  • 45.
    Almlöf, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Kreutz, Bjørn
    Borregaard Chemcell, Norway.
    Jardeby, Kristina
    Borregaard Chemcell, Norway.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    The influence of extended mercerization on some properties of carboxymethyl cellulose (CMC)2012In: Holzforschung, ISSN 0018-3830, Vol. 66, 21-27 p.Article in journal (Refereed)
    Abstract [en]

    Carboxymethyl cellulose (CMC) is produced commercially in a two stage process consisting of a mercerization stage in which the pulp is treated with alkali in a water alcohol solution and a second etherification stage whereby monochloro-acetic acid is added to the pulp slurry. In this study, the influence of the conditions of an extended mercerization stage was evaluated on the etherification stage concerning the degree of substitution (DS) and the filterability of the resulting CMC. The parameters studied were: (1) the ratio of cellulose I and cellulose II in the original pulp, (2) the concentration of alkali, (3) the temperature and (4) the retention time in the mercerization stage. The DS results indicate that the NaOH concentration in the mercerization stage is the most important among the parameters studied. When the NaOH concentration in the mercerization stage was high (27.5%), cellulose II showed a lower reactivity than cellulose I with respect to the DS obtained in the resulting CMC. The results from the filtration ability of CMC water solutions are interpreted that the amount of cellulose II in the original pulp and the temperature has a negative influence, while the NaOH concentration in the mercerization stage has a positive influence on the filtration ability. Retention time between 1 h–48 h in the mercerization stage had no effect on the DS or the filtration value. The filtration ability was assumed to be highly influenced by the presence of poorly reacted cellulose segments. The CMC samples with the lowest filtration ability at a given DS can be assumed to have the highest degree of unevenly substituted segments.

  • 46.
    Almlöf, Heléne
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Schenzel, Karla
    Department of Natural Science III, Institute of Agriculture and Nutritional Science, Martin Luther University, Germany.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Carboxymethyl cellulose produced at different mercerization conditions and characterized by NIR FT Raman spectroscopy and chemometric methods2013In: BioResources, ISSN 1930-2126, Vol. 8, no 2, 1918-1932 p.Article in journal (Refereed)
  • 47.
    Almqwist, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science.
    Olsson, Robert
    Karlstad University, Faculty of Technology and Science.
    Val av fönster med hjälp multikriterieanalys: Forshaga vårdcentral2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Rapporten är tänkt som ett hjälpmedel vid fönsterprojektering och berör de aspekter som är av intresse vid val av fönster. Målgruppen är Landstingsfastigheter i Värmland (LIV) samt alla som har intresse av ämnet. Huvudsyftet är att förenkla för LIV i deras arbete att välja fönster och att lämna förslag på den bästa fönster-/solskyddslösningen till vårdcentralen i Forshaga.

    Målet med rapporten är att skapa ett verktyg som hjälper LIV att på ett objektivt och enkelt sätt välja sina framtida fönster-/solskyddslösningar.

     

    Med hjälp av en multikriterieanalys (MKA) i samverkan med uppställda mål och syften har en mall arbetats fram, där fönster/solskydd kan utvärderas på ett objektivt sätt. MKA:n fungerar bra vid jämförelse av fönster men inte vid solskydd. Detta eftersom LIV har satt upp tydliga mål och syften för sin solskyddslösning. Därmed har en undersökande metod med hjälp av LIV:s uppställda krav använts som hjälpmedel vid val av solskyddslösning. MKA-metoden tillämpades för att finna det bästa fönstret till vårdcentralen i Forshaga.

     

    Rapporten visar att med LIV:s förutsättningar är den bästa lösningen ett PVC-fönster med isolerglas. PVC-karmen är den lösning som ger lägst U-värde samt kostar minst i sammanhanget. Trots att PVC-fönstret redovisas som vinnare var det inte bäst i alla avseenden. Aluminiumfönstret är genomgående bra och bäst ur säkerhetssynpunkt men tillverkarna har svårt att minska de naturliga köldbryggorna som uppstår i karmen. Lösningarna blir dyra och fönstret är svårt att motivera ekonomiskt när säkerhetskraven är normala. Fönster med trä respektive trä-/aluminiumkarm får också ett genomgående gott betyg. Ur underhållssynpunkt har träkarmen svårt att mäta sig med de underhållsfria alternativen.

     

    Eftersom LIV har tydliga krav och mål uppställda på sina solskyddslösningar och på deras funktion, sorterades många lösningar bort. Skärningspunkten för alla kriterier föll på en fast solavskärmning som inte kräver något underhåll, eller vars funktion förändras av väder och vind. Solavskärmningen bör kombineras med en persienn för att möjliggöra ett gott insynsskydd.

    En slutsats vid val av fönster är att det är viktigt att ha tydliga mål och syften, först när det är färdigställt kan man gå vidare med vilken funktion och krav fönstret/solskyddet bör uppfylla.

  • 48.
    Almström, Linda
    et al.
    Karlstad University, Faculty of Technology and Science.
    Söderström, Camilla
    Karlstad University, Faculty of Technology and Science.
    Alternative materials for high-temperature and high-pressure valves2010Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    AB SOMAS Ventiler manufactures valves for different applications. A valve of type DN VSSL 400, PN 100, used in high-temperature and high-pressure applications was investigated in this thesis. This type of valve is coated with high cobalt alloys to achieve the tribological properties needed for this severe condition. However there is a request from AB Somas Ventiler to find another solution. This request is based on the fact that demands on higher temperatures, from customers, yields higher requirements on the material. It is also a price issue since cobalt is quite expensive. Materials investigated were high-nitrogen steel, Vanax 75, nickel-based superalloy Inconel 718 and hardened steels, EN 1.4903 and EN 1.4923 presently used as base material in the valve.

    Calculation of contact pressure that arises when the valve is closed was first approached by using finite element method (FEM). Several models were constructed to show the behavior of the valve during closing in terms of deformation. Hot wear tests, in which a specimen was pressed against a rotating cylinder, were performed to be able to compare the materials to the solution of today and among each other. Data extracted from the tests were compiled in the form of coefficients of friction. Profilometer examinations were used to reveal the volumes of worn and adhered material and together with scanning electron microscopy (SEM) the wear situation for each material couple could be assessed.

    Wear mechanisms detected in SEM were adhesive and abrasive and the results clearly showed that the steels were not a good solution because of severe adhesive wear due to the similarity of mating materials creating a more efficient bonding between the asperities. Vanax 75 showed much better performance but there was still an obvious difference between the steels and the superalloy in terms of both coefficient of friction and amount of wear. On this basis, Inconel 718 was selected as the most suitable material to replace the high cobalt alloys used in the valves today.

  • 49.
    Almusaed, Amjad
    et al.
    Archcrea Institute.
    Almssad, Asaad
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Biophilic Habitat: Environment Adaptability In Context Of BioEcological Architectural Conception2010In: 3rd International Conference Palenc 2010 jointly organised with EPIC 2010 & 1st Cool Roofs Conference, University of Athens, Greece , 2010Conference paper (Refereed)
    Abstract [en]

    The vital objective of biophilic habitat is to outline attributes and put them into a clear, sensible, organized format so developers, designers, planners, and architects can learn about the importance of a connection to the natural environment in all their building projects. Renew ability is the key to our human range and our prime resource for architecture. Every site is definite as to its location, natural relief, local vegetation, and its macro-microclimate.

    Biophilic habitat becomes an original utterance in social requirement. Moreover, this concept becomes a truly new orientation of human cultural life. Biophilic habitat is a part of a new concept in architecture, that work intensive with human health, ecology and sustainability precepts, such a integrate part of architectural formation which must be in optimal proportion with other buildings material. The position of green covering and its area depend basically on the category of functions that occur under this area. Biophilic habitat produces buildings that use less energy to operate because they feature efficient designs, materials and systems. The majority biophilic architectures have highly competent heating, cooling, ventilation, lighting systems, and appliances. In addition, these biophilic restructures are built of energy-efficient materials carefully installed to prevent the loss of conditioned.

  • 50.
    Alriksson, Björn
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Ethanol from lignocellulose: Alkali detoxification of dilute-acid spruce hydrolysates2006Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Detoxification of dilute-acid lignocellulose hydrolysates by treatment with Ca(OH)2 (overliming) efficiently improves the production of fuel ethanol, but is associated with drawbacks like sugar degradation and CaSO4 precipitation. In factorial designed experiments, in which pH and temperature were varied, dilute-acid spruce hydrolysates were treated with Ca(OH)2, NH4OH or NaOH. The concentrations of sugars and inhibitory compounds were measured before and after the treatments. The fermentability was examined using the yeast Saccharomyces cerevisiae and compared with reference fermentations of synthetic medium without inhibitors. The treatment conditions were evaluated by comparing the balanced ethanol yield, which takes both the degradation of sugars and the ethanol production into account. Treatment conditions resulting in excellent fermentability and minimal sugar degradation were possible to find regardless of whether Ca(OH)2, NH4OH or NaOH was used. Balanced ethanol yields higher than those of the reference fermentations were achieved for hydrolysates treated with all three types of alkali. As expected, treatment with Ca(OH)2 gave rise to precipitated CaSO4. The NH4OH treatments gave rise to a brownish precipitate but the amounts of precipitate formed were relatively small. No precipitate was observed in treatments with NaOH. The possibility that the ammonium ions from the NH4OH treatments gave a positive effect as an extra source of nitrogen during the fermentations was excluded after experiments in which NH4Cl was added to the medium. The findings presented can be used to improve the effectiveness of alkali detoxification of lignocellulose hydrolysates and to minimize problems with sugar degradation and formation of precipitates.

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