Change search
Refine search result
9101112131415 551 - 600 of 64687
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 551.
    Adolfsson, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Cementitious properties of steelmaking slags2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present study is directed towards the use of steelmaking slags as raw material for sulphoaluminate belite cement (SAB). Another important objective was to characterise the cementitious properties of phases in ladle furnace slag (LFS) specifically the calcium aluminates. Mayenite (C12A7) is considered one of the most important calcium aluminate in LFS, and since comparatively limited data on the kinetic properties of this phase are available, it was decided to study C12A7 more closely with regard to both particle size and temperature sensitivity. The behaviour of high-temperature reactions of tested SAB mixtures was investigated using thermogravimetric analysis coupled with a quadrupole mass spectrometer. Mineralogical observations were carried out with x-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results proved that steelmaking slags have the potential to work as raw material, since sulphoaluminate (C4A3 S ) along with polymorphs of dicalcium silicate (C2S) and ferrite phase (C4AF) were detected after firing at 1200ºC in an air atmosphere. The hydration properties of the specimens were analysed through conduction calorimetry, and compressive strength of specimens hydrated for 2 and 28 days. The compressive strength was in accordance with that suggested in the literature for slow hardening SAB cement. Both mixtures tested behaved the same with regard to heat development as well as the amount of ettringite (AFt) formed during the first 24 hours of the hydration. The formation of AFt was characterised with both differential scanning calorimeter (DSC) and XRD. The crystallographic distribution in LFS samples was quantified using Rietveldanalysis. Calorimetric studies were performed at 20, 25 and 30°C in order to calculate the activation energy of hydration and thereby to suggest a kinetic model for tested compositions within this temperature interval. In addition to heat of hydration, compressive strength tests were completed on mortar prisms of LFS, and LFS in a blend with ground granulated blast furnace slag (GGBFS) which hydrated for 2, 7 and 28 days. Both compositions reached acceptable early strengths, whereas, after 28 days hydration, the blend was superior to neat LFS. Related activation energy was according to the Avrami-Erofeev model determined to 58 kJ/mol for the LFS and 63 kJ/mol for the blend. Corresponding calorimetric studies at the same temperatures were performed on a fine and coarse size fraction (Fraction A and Fraction B) of a synthesised C12A7. The purity was confirmed by XRD, and the hydraulic behaviour was investigated in excess water with respect to the dissolution. The apparent activation energy was calculated to 33 and 79 kJ/mol, respectively, for Fractions A-B using the Avrami-Erofeev model. From the model, it was also concluded that the acceleration period can be ascribed to a phase-boundary controlled mechanism. The principal calcium aluminate hydrates obtained were C2AH8 and C2AH7.5, and it was further observed that C12A7 is accompanied by an anomalous setting behaviour much like monocalcium aluminate (CA), and that the decomposition of C2AH8 to C2AH7.5 develops more slowly with higher surface area, specifically at 20 and 30°C.

  • 552. Adolfsson, Daniel
    Steelmaking slags as raw material for sulphoaluminate belite cement2007Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present work was undertaken as part of the research in the Minerals and Metals Recycling research centre, MiMeR. The course of the thesis is attributed to metallurgical slags from the steelmaking industry and the possible use of such by-products as raw material for sulphoaluminate belite cement (SAB). Implementing steel slags into the production of cement could contribute to the steel industry's possibility of increasing the recirculation. In addition to the previous objective, the introduction of slag into the cement manufacturing can also facilitate the reduction of carbon dioxide emissions as well as lowering the overall energy consumption during the manufacturing. The reason for this is that the SAB system enables the reduction of the lime saturation factor (LSF) which in turn implies that less limestone is needed in the raw meal. Additionally, the firing temperature can be reduced by about 100-150°C, since dicalcium silicate and sulphoaluminate are formed already at approximately 1200-1250°C. In any event, one should remember that this is not intended to be a final solution for the recycling of slag, nor a replacement for already accepted cement materials. A number of applications currently exist where ordinary Portland cement (OPC) is used, but in cases where the OPC could be replaced with other type of cements, e.g. SAB cement, the possibility of using residues material in cement applications is increased. Considering the clinker covered within this work, possible applications are those where slow hydraulic properties are suitable. The behaviour of high temperature reactions of tested mixtures was investigated using thermogravimetric analysis coupled with a quadrupole mass spectrometer. Mineralogical observations were carried out with x-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results proved that steelmaking slags have the potential to work as raw material, since sulphoaluminate along with polymorphs of dicalcium silicate and ferrite phases were detected after firing at 1200 ºC in an air atmosphere. The hydraulic properties of the specimens were analysed through conduction calorimetry, XRD, differential scanning calorimetry (DSC) as was the mechanical strength of the specimens when hydrated for 2 and 28 days. The compressive strength was in accordance with that suggested in the literature for slow hardening SAB cement. Both mixtures tested behaved the same with regard to heat development as well as the amount of AFt formed during the first 24 hours of the hydration.

  • 553. Adolfsson, Daniel
    et al.
    Engström, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Robinson, Ryan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Cementitious phases in ladle slag2011In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 82, no 4, p. 398-403Article in journal (Refereed)
    Abstract [en]

    Ladle slag is an internal by-product generated within the steelmaking industry during the refining of steel. The realisation of beneficial inherent properties of ladle slag as a binder supplement or substitute material is believed to be advantageous with respect to both economy and environment for steelmakers. For this reason, the current study has focused on highlighting the properties of ladle slag that are pertinent to the formation of calcium aluminate hydrates. Three fractions of ladle slag, two of which were based on different slag formers, have been characterised using XRF, XRD and calorimetric analysis. Commonly known hydraulic minerals such as mayenite, tricalcium aluminate and dicalcium silicate were detected during analysis. An important aspect in the utilisation of ladle slag is the slag handling methodology. Therefore, this study also highlights and discusses the need to reconsider slag handling procedures concerning unnecessary exposure to weathering and the possible need for further processing of the slag in order to better employ the inherent hydraulic properties of this material.

  • 554. Adolfsson, Daniel
    et al.
    Menad, Nourreddine
    Viggh, Erik O.
    Bureau de Recherches Géologiques et Minières, Orléans.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hydraulic properties of sulphoaluminate belite cement based on steelmaking slags2007In: Advances in Cement Research, ISSN 0951-7197, E-ISSN 1751-7605, Vol. 19, no 3, p. 133-138Article in journal (Refereed)
    Abstract [en]

    Based on modified Bogue calculations, steelmaking slags were combined in order to produce a belite-rich clinker activated with sulphoaluminate. The experiments were conducted on two different mixtures based on steelmaking slags together with additives, namely MixA and MixB. The objective of the present study was to investigate the hydraulic properties of the specimens, using conduction calorimetry, X-ray diffraction and differential scanning calorimetry, and also to measure the mechanical strength of the specimens when hydrated for 2 and 28 days. The compressive strength was satisfactory in relation to the estimated compositions. Both mixtures behaved the same with regard to heat development as well as the amount of ettringite formed during the first 24 h of the hydration.

  • 555. Adolfsson, Daniel
    et al.
    Menad, Nourreddine
    Viggh, Erik O.
    Cementa AB, Malmö.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Steelmaking slags as raw material for sulphoaluminate belite cement2007In: Advances in Cement Research, ISSN 0951-7197, E-ISSN 1751-7605, Vol. 19, no 4, p. 147-156Article in journal (Refereed)
    Abstract [en]

    In the present study, slags from the steelmaking industry are described and considered as a potential raw material within the field of sulphoaluminate belite cement. The objective of the study was to investigate the possibility of using a substantial amount of steelmaking slags as raw meal in the manufacture of a sulphobelitic clinker. A further aim was to compare the influence of different slags in relation to the formation of sulphoaluminate and the other clinker phases required. The behaviour of high temperature reactions was investigated by using thermogravimetric analysis coupled with a quadrupole mass spectrometer. Mineralogical observations were carried out through X-ray powder diffraction, and scanning electron microscopy. Three different mixtures and a single ladle slag were prepared using modified Bogue calculations, which are characterised by the assessment of a potential phase composition in order to produce belite-rich cement activated with sulphoaluminate. The results so far prove that steelmaking slags have the potential to be used as raw material, since sulphoaluminate along with polymorphs of dicalcium silicate and ferrite phases were detected after firing at 1200 degrees C in an air atmosphere.

  • 556. Adolfsson, Daniel
    et al.
    Robinson, Ryan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Blagojevic, J.
    SSAB Tunnplåt AB.
    Su, F.
    SSAB Tunnplåt AB.
    Assessment of ladle slag as binder alternative for cold bonded briquettes2008In: REWAS 2008: Global Symposium on Recycling, Waste Treatment and Clean Technology ; held October 12 - 15, 2008 in Cancun, Mexico / [ed] B. Mishra; C. Ludwig; S. Das, Minerals, Metals & Materials Society, 2008, p. 117-123Conference paper (Refereed)
    Abstract [en]

    Cold bonded briquetting of steel plant by-products has proven to be a viable recycling alternative concerning technology, economy and environment in both the traditional blast furnace route and the direct reduction process. A critical parameter in cold bonded briquettes is the type and amount of binder used during production. The binder material must meet certain quality requirements concerning low and high temperature strength, chemistry and economy. Currently, SSAB Tunnplåt uses ordinary Portland cement (OPC) as binder in their cold bonded briquettes. In order to improve binder quality and possibly decrease OPC dependency, a binder feasibility study has been conducted concerning an internal by-product, ladle slag, as a supplement and/or partial substitute for OPC. Several characterization techniques have been used to study the behaviour of ladle slag, these include: XRD, XRF, SEM, glass content analysis, calorimetric analysis, particle size distribution and thermochemical stability considerations concerning the CaO-Al2O3-SiO 2 system.

  • 557. Adolfsson, Daniel
    et al.
    Robinson, Ryan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Blagojevic, J.
    Su, F.
    Assessment of ladle slag as bnder alternative for cold bonded briquettes2008In: REWAS 2008: Global Symposium on Recycling, Waste Treatment / [ed] B. Mishra; C. Ludwig; S. Das, Minerals, Metals & Materials Society, 2008, p. 117-124Conference paper (Refereed)
  • 558.
    Adolfsson, Daniel
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Robinson, Ryan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Engström, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Influence of mineralogy on the hydraulic properties of ladle slag2011In: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 41, no 8, p. 865-871Article in journal (Refereed)
    Abstract [en]

    The present study is aimed at investigating the hydraulic characteristics of ladle furnace slag (LFS), under the pretence of using LFS as a cement substitute in certain applications. Furthermore, LFS has been considered as a possible activator in a blend containing 50% LFS, and 50% ground granulated blast furnace slag (GGBFS). Phases detected in LFS were quantified using Rietveld analysis. Calorimetric studies were performed at 20, 25 and 30 °C in order to calculate the apparent activation energy of hydration and thereby to suggest a kinetic model for the tested compositions within this temperature interval. In addition, compressive strength tests were performed on mortar prisms made with LFS, and LFS/GGBFS which had hydrated for 2, 7 and 28 days. Both compositions reached acceptable early strengths, (e.g. LFS, 33.1 MPa, and LFS/GGBFS, 17.9 MPa, after 2 days), but after 28 days hydration the blend was superior to neat LFS. Related apparent activation energies were determined using an Avrami–Erofeev model and gave Ea = 58 kJ/mol for neat LFS and Ea = 63 kJ/mol for the blend. The results imply that LFS or a LFS/GGBFS blend can be favourably used as supplement in binder applications such as binder in by-product metallurgical briquettes, which are used as recycle to the blast furnace or basic oxygen furnace depending on the specific briquette composition.

  • 559. Adolfsson, Daniel
    et al.
    Viggh, Erik O.
    Cementa AB.
    Steelmaking slags as raw material for calcium sulfoaluminate belite cement2005In: Securing the future: international conference on mining and the environment, metals and energy recovery : proceedings, Stockholm: SweMin , 2005, p. 8-Conference paper (Other academic)
  • 560. Adolfsson, Emelie
    et al.
    Wahlnemo, Lina
    Twitter bland journalister: En fältstudie om journalisters användning av Twitter2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 561. Adolfsson, Erik
    Virtuell simulering av verktygsmaskiner2002Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 562. Adolfsson, Frida
    et al.
    Gjertz Granström, John
    Upplevelsen av ensamhet vid kronisk sjukdom2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 563. Adolfsson, Henrik
    et al.
    Haapaniemi, Henrik
    Barn och trafik: ett försök att öka barns trafikmedvetenhet2003Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 564.
    Adolfsson, Isabella
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Hägge, Magdalena
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Organisatorisk lojalitet i en turbulent tid av hög tillväxt: En empirisk studie av 223 anställda i svenska gasellföretag2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Organizational commitment is one important factor for organization performance and efficiency. During the last years, the interest for new and fast growing companies and their effect for the economic growth has increased. Studies within gazelle companies has earlier been based on their founders and managers. The purpose of this study is therefore to examine the employees’ organizational commitment and which factors affect the commitment. The study had a quantitative approach and was carried out with the help of a survey where 223 respondents participated. All respondents are working at Swedish gazelle companies. The collected data of the study were analysed by using a multivariate regression and path analysis. Cronbach’s alpha was used to test the measures reliability. The result show that there is a positive correlation between the employees’ nearness to the founder, recognition and job satisfaction with organizational commitment. The result also show that there is a negative correlation between monetary incentive and organizational commitment. The results provide indications for how managers in gazelle companies should work with these components and thereby increase the degree of organizational commitment to control the organizations growth in a better way.

  • 565.
    Adolfsson, JanEric
    Luleå tekniska universitet.
    Drift och underhåll av vägar och gator: behovet av forskning och utveckling hos sex kommuner1983Report (Other academic)
  • 566.
    Adolfsson, JanEric
    et al.
    Luleå tekniska universitet.
    Boman, Jan
    Luleå tekniska universitet.
    Bylund, Anders
    Luleå tekniska universitet.
    Sandberg, Marika
    Luleå tekniska universitet.
    Drift och underhåll på gator och vägar: en studie av ett område i Luleå1984Report (Other academic)
  • 567. Adolfsson, Janette
    Kvalitetsutvecklingsplan för SN Elteknik AB och Byggkonsult Ove Eriksson AB: förslag på modell för fortsatt arbete med totalkvalitet1999Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 568. Adolfsson, Josefine
    et al.
    Keddie, Josefine
    Röntgensjuksköterskans och röntgenundersökningens betydelse vid utredning av barnmisshandel: En litteraturstudie2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Introduction: Most children in Sweden have a good state of health and grow up in secure conditions in full compliance with the Parental Code. This doesn’t always match reality because there are children who are abused. Child abuse is a global problem, and in countries with a strong economy 4-16 % of the children suffer from abuse every year.Objective: The purpose of this study was to provide a general literature review describing the radiographer’s and x-ray’s importance when conducting an enquiry of child abuse. Method: The study was conducted as a general literature review and contains 11 scientific articles that are selected according to the purpose.Results: The study showed that x-ray plays an important role when it comes to the investigation of child abuse. It is an effective way to detect fractures and fissures which are one of the most common signs of physical abuse of children. The study showed that children under 2 years ran a higher risk of abuse than older children, and that most x-ray examinations were carried out on these. With the help of the initial x-ray and eventual follow-up x-ray, the radiographer can contribute to the diagnosis. However, radiographers still feel that they don’t have adequate knowledge in child abuse. Conclusion: X-ray is recommended when it comes to the investigation of suspected child abuse. It helps to detect fractures and fissures, which in turn leads to the diagnosis of child abuse. Radiographers are recommended to upgrade their knowledge and education about child protection and abuse, as well as striving to improve their technique in performing the x-ray examinations.

  • 569. Adolfsson, Linn
    En tillgänglig, trygg och attraktiv vinterstad: En studie av hur tillgänglighet, trygghet och attraktivitet bidrar till att skapa en vinterstad anpassad för dess invånare2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 570.
    Adolfsson, Rasmus
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Hannercrantz, André
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Optimering av orderstorlek ur ett kostnads- och produktivitetsperspektiv: en kvantitativ fallstudie på Zoégas i Helsingborg2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate optimal order quantities at the coffee producer Zoéga’s packaging lines in Helsingborg. The company is currently unaware of how order quantities affect their production; with regards to productivity as well as setup- and holding costs. With a long-term vision of incorporating “pull planning”, the case company also needs to evaluate the capabilities of their current production system.

    The case study mainly addresses two areas; one comparing historical productivity in relation to order quantity, and one determining optimal order quantity with the scheduling-tool known as “Economic lot scheduling problem”. One of the packaging lines results in a classic case of “Basic period approach”, a problem frequently reviewed in ELSP-literature. The other lines have sequence dependent setup times, which required a more complex model. The primarily data collection has been from internal production- and management systems.

    The ELSP-results generated optimal order quantities and production schedules for all packaging lines. The study also found statistically significant correlations between order quantity and productivity for Zoéga’s. These correlations compiled upper and lower limits for the most productive order quantities; where most of the ELSP-quantities placed inside these limits. Finally, the study shows that by implementing these suggestions, Zoéga’s could speed up their product turnover and be better prepared for “pull planning” implementation in the future.

  • 571.
    Adolfsson, Stefan
    Luleå tekniska universitet.
    Quality monitoring in pulsed GMA welding using signal processing methods1995Licentiate thesis, comprehensive summary (Other academic)
  • 572.
    Adolfsson, Stefan
    et al.
    Luleå tekniska universitet.
    Ericsson, Klas
    Luleå tekniska universitet.
    Grennberg, Anders
    Automatic detection of burn-through in GMA welding using a parametric model1996In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 10, no 5, p. 633-651Article in journal (Refereed)
    Abstract [en]

    This paper addresses the problem of automatic detection of burn-through in weld joints. Gas metal arc (GMA) welding with pulsed current is used, and welding voltage and current are recorded. As short-circuitings are common between the welding electrode and the work piece during burn-through, a short-circuit detector is developed to detect these events. To detect another specific characteristic of burn-through - this detector is combined with a square-law detector. This second detector is based on a non-linear modification of an autoregressive model with extra input (ARX-model) of the welding process. The results obtained from this compound detector indicate that it is possible to detect burn-through in the welds automatically. The work also indicates that it is possible to design an on-line monitoring system for robotic GMA welding.

  • 573. Adolfsson, Ulrica
    Invandrares etablering på arbetsmarknaden i Norrbotten2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 574. Adolfsson, Ulrica
    Valfrihet inom äldreomsorgen i Bodens kommun i ett brukarperspektiv2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Customer choice means that customers, who are in need of a product, service or any kind of service, could have more impact and more opportunity to influence the activities they are dependent of. Customer choice models are introduced at a rapid pace today in several municipalities and counties. About Freedom of Choice Act (LOV), introduced January 1, 2009 is to facilitate this development. Today is the customers who need home care able to choose providers in the communities that have chosen to implement LOV. Now that the municipalities in the future to meet the competition they will face in the LOV, it is interesting to look at what the customers in the current situation, the possibilities of choice, think about this.My purpose was to conduct a study of user model used in the municipality of Boden. This is to be able to contribute important knowledge from this work to a subsequent, broader evaluation of the choice systemThe study is qualitative and it is conducted five interviews with customers who have home-help both through the agency of the municipality and a private provider. This was done to gain a deeper understanding of how customers perceive the choice they have been incorporated by the introduction of LOV. The theoretical framework consists of concepts: the user-oriented management model, generations, public institutions cases, the individualized society and evaluation.The results show that the generation that currently affected by the choice models do not have knowledge of what choice means for them. The information from local governments should be reviewed and adjusted so that provided this information understands what it means and what opportunities there are. The next generation in need of assisted living has grown up with entirely different conditions than the current home care clients, they have been through growing up a point to choose and cut, and only then will choice model to function as intended.

  • 575.
    Adrielsson, Anders
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Zedboard based platform for condition monitoring and control experiments2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    New methods for monitoring the condition of roller element bearings in rotating machinery offer possibilities to reduce repair- and maintenance costs, and reduced use of environmentally harmful lubricants. One such method is sparse representation of vibration signals using matching pursuit with dictionary learning, which so far has been tested on PCs with data from controlled tests. Further testing requires a platform capable of signal processing and control in more realistic experiments. This thesis focuses on the integration of a hybrid CPU-FPGA hardware system with a 16-bit analog-to-digital converter and an oil pump, granting the possibility of collecting real-time data, executing the algorithm in closed loop and supplying lubrication to the machine under test, if need be. The aforementioned algorithm is implemented in a Zynq-7000 System-on-Chip and the analog-to-digital converter as well as the pump motor controller are integrated. This platform enables portable operation of the matching pursuit with dictionary learning in the field under a larger variety of environmental and operational conditions, conditions which might prove difficult to reproduce in a laboratory setup. The platform developed throughout this project can collect data using the analog-to-digital converter and operations can be performed on that data in both the CPU and the FPGA. A test of the system function at a sampling rate of 5 kHz is presented and the input and output are verified to function correctly.

  • 576.
    Adu, Cynthia
    et al.
    Manufacturing and Materials Department, Cranfield University.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Eichhorn, Stephen J.
    Bristol Composites Institute (ACCIS), Queens Building, School of Engineering, Bristol University.
    Jolly, Mark
    Manufacturing and Materials Department, Cranfield University.
    Zhu, Chenchen
    Bristol Composites Institute (ACCIS), Queens Building, School of Engineering, Bristol University.
    Properties of cellulose nanofibre networks prepared from never-dried and dried paper mill sludge2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 197, no 1, p. 765-771Article in journal (Refereed)
    Abstract [en]

    Paper mills yield large volumes of sludge materials which pose an environmental and economic challenge for disposal, despite the fact that they could be a valuable source for cellulose nanofibres (CNF) production. The aim of the study was to evaluate the production process and properties of CNF prepared by mechanical fibrillation of never-dried and dried paper mill sludge (PMS). Atomic force microscopy (AFM) showed that average diameters for both never-dried and dried paper sludge nanofibres (PSNF) were less than 50 nm. The never-dried and dried sludge nanofibres showed no statistical significant difference (p > 0.05) in strength 92 MPa, and 85 MPa and modulus 11 GPa and 10 GPa. The study concludes that paper mill sludge can be used in a dried state for CNF production to reduce transportation and storage challenges posed on industrial scale.

  • 577.
    Advani, Suresh G.
    et al.
    University of Delaware, Department of Mechanic Engineering.
    Talreja, Ramesh
    A continuum approach to determination of elastic properties of short fibre composites1993In: Mechanics of composite materials, ISSN 0191-5665, E-ISSN 1573-8922, Vol. 29, no 2, p. 127-137Article in journal (Refereed)
  • 578.
    Aerila, Juli-Anna
    et al.
    University of Turku.
    Kokkola, Lydia
    Luleå University of Technology, Department of Arts, Communication and Education, Education, Language, and Teaching.
    Multicultural literature and the use of literature in multicultural education in Finland2013In: Bookbird: A Journal of International Children's Literature, ISSN 0006-7377, E-ISSN 1918-6983, Vol. 51, no 2, p. 39-50Article in journal (Refereed)
    Abstract [en]

    This paper traces the presentation of these traditional minority groups in Finland and the emergence of literature incorporating the more recently arrived groups of immigrants in the history of Finnish language children’s literature. We contextualize the development of multicultural themes in children’s literature within the history of Finnish nation-building and the country’s struggles for independence. We conclude with a brief consideration of how these less than ideal books might, nevertheless, serve to promote pluralism.

  • 579. af Kleen, Kaj
    et al.
    Klingensjö, Oscar
    Samarbete i försörjningskedjan för balans mellan en leverantörs utbud och konsumentens efterfrågan: en fallstudie i kosmetikbranschen2008Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 580. af Petersens, Magnus
    Modell för lerans odränerade skjuvhållfasthet i anslutning till Göta älv2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A common issue in stability analyses preformed in connection to Göta River and otherwatercourses is how the undrained shear strength of the clay should be modeled in transitionbetween land and river. This issue is in Sweden relatively unexplored and only a fewguidelines and publications are available regarding the subject. Furthermore, geotechnicalfield investigations are relatively expensive when preformed in the water areas which resultsin a limited surveyed data. The consequence of these aforementioned factors frequentlycreates underestimated, undrained shear strength. This will eventually result in a misleadingoverall safety factor in the analysis.The aim of the thesis has been to suggest a model of how the undrained shear strength shouldbe modeled in the labeled transition zone, based on a large amount of geotechnical surveysand the geological history. Geotechnical investigations have been studied in five sections inthe southern region of the Göta River. These studies include measured; undrained shearstrength, consolidation conditions and basic material properties of the clay. The results ofthese studies show that the shallow sediments in the river bed, has significantly lowerundrained shear strength than the corresponding level at the shore. The clay layer which hasthis lower shear strength corresponds to the actual water depth. In deeper areas of the riverbed the shear strength is similar from land to the river area. The undrained shear strengthseems to have a parable increment in this clay layer with lower shear strength.Several empirical calculations have been performed and compared to the geotechnical surveysto examine how well the undrained shear strength can be estimated, primarily the area of theriver bed with lower strength. It has been shown that the empirical estimation requires a lot ofknowledge, in particular consolidation conditions and stress distribution as a result of loadingand unloading.Furthermore, a simple stress analysis has been performed in Plaxis to illustrate the effectivestress distribution as well as the stress dispersion as a result of loading and unloading in anhomogeneous clay. The result shows in particular that the stress dispersion effects arisingcollaterally at both loading and unloading.A generalized stability analysis was executed to reveal how the different ways to model theundrained shear strength affects overall safety factor. This analysis resulted in a significantlyhigher overall safety factor, when the undrained shear strength was modeled according to themeasured results than how it has been modeled in many previously investigations.It may finally be noted that the uncertainties regarding how the undrained shear strengthshould be modeled in many cases has resulted in a conservative way to model the undrainedshear strength. in which the consequence has been an underestimated overall safety factor.

  • 581. af Sandeberg, Viktor
    S-Band Transmitter for NAROM Student Rocket2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Norwegian Centre for Space-related Education (NAROM) performs education within subject areas related to space, such as space physics, atmosphere and space technology. This thesis describes the development of a transmitter to be used in NAROM ́s studentrocket. The requirements were that the transmitter should send with FM at 2279,5 MHz with an output of at least 750 milliwatt and with a speed of 512 kbit/s when NRZ coding is used.The transmitter that was designed and tested in this project used an IC that modulated the signal to FM and sent it out on a low frequency. Then the frequency was multiplied by a IC to the correct value, 2279,5 MHz. Experiments showed that the transmitter worked satisfying, but a problem occurred: The frequency multiplier sent out unwanted overtones and the output power was to low. A final theoretical design was made to solve these problems. The final design uses the same modulation components as the tested transmitter, but filters are added and the amplifiers are changed to be able to handle the filters and give out a higher power. The transmitter can be use for other application that need a transmitter with bit-rate of up to 600 kbit/s and frequency range of 2250-2300 MHz without change of filters. If the filters is change the frequency range will be 2250-2550 MHz.

  • 582.
    Afanasiev, Sergey V.
    et al.
    Joint Institute for Nuclear Research Joliot-Curie 6.
    Afonin, Alexander G.
    Institute of High Energy Physics - Moscow Region.
    Ambrosi, Giovanni
    INFN Sezione di Perugia.
    Azzarello, Philipp
    INFN Sezione di Perugia.
    Baranov, Vladimir T.
    Institute of High Energy Physics - Moscow Region.
    Baricordi, Stefano
    INFN Sezione di Ferrara.
    Battiston, Roberto
    INFN Sezione di Perugia.
    Bertucci, Bruna
    INFN Sezione di Perugia.
    Bolognini, Davide
    Università dell'Insubria.
    Burger, William J.
    INFN Sezione di Perugia.
    Carnera, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Cavoto, Gianluca
    INFN Sezione di Roma.
    Chesnokov, Yury A.
    Institute of High Energy Physics - Moscow Region.
    Dalpiaz, Pietro
    INFN Sezione di Ferrara.
    Mea, Gianantonio Della
    INFN Laboratori Nazionali di Legnaro.
    Denisov, Alexander S.
    Petersburg Nuclear Physics Institute.
    Salvador, Davide De
    INFN Laboratori Nazionali di Legnaro.
    Fiorini, Massimiliano
    INFN Sezione di Ferrara.
    Foggetta, Luca
    Università dell'Insubria.
    Gavrikov, Yury A.
    Petersburg Nuclear Physics Institute.
    Guidi, Vincenzo
    INFN Sezione di Ferrara.
    Hasan, Said
    Università dell'Insubria.
    Ionica, Maria
    INFN Sezione di Perugia.
    Ivanov, Yuri M.
    Petersburg Nuclear Physics Institute.
    Ivochkin, Vladimir G.
    Petersburg Nuclear Physics Institute.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Zuccon, Paolo
    INFN Sezione di Perugia.
    Experimental apparatus to study crystal channeling in an external SPS beamline2007In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6634Article in journal (Refereed)
    Abstract [en]

    For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets.1 We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μrad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass efficiency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.

  • 583.
    Afanasieva, Rallema
    et al.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Bessanova, Nina
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistrova, Olga
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistov, V.M.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Holmér, Ingvar
    National Institute for Working Life.
    Kuklane, Kalev
    Sravnitel'naia otsenka metodov opredeleniia summarnogo teplovogo soprotivleniia komplekta spetsodezhdy dlia zashchity ot kholoda, predusmostrennykh Rossiiskim i mezhdunarodnym standartami: Comparative evaluation of methods accepted by Russian and international standards to assess total resistance of special cold-proof clothing set1999In: Meditsina truda i promyshlennaia ekologiia, ISSN 1026-9428, Vol. 12, p. 18-24Article in journal (Refereed)
    Abstract [en]

    Experimental studies helped to compare methods determining and calculating total heat resistance of clothing sets accepted by Russian and international standards. Findings are that difference in the total heat resistance values calculated on humans and on dummies in relatively still air and quiet conditions is caused by measurement technique applied. Significant difference in the total heat resistance values calculated in windy conditions or during walk require further research aimed to study influence of those factors on clothes' heat resistance

  • 584.
    Afanasieva, Rallema F.
    et al.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Bessanova, Nina A.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistrova, Olga V.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistrov, Vyacheslav M.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Holmér, Ingvar
    National Institute for Working Life.
    Kuklane, Kalev
    Luleå tekniska universitet.
    Comparative evaluation of the methods for determinating thermal insulation of a clothing ensemble on a manikin and person2000In: Ergonomics of protective clothing: proceedings of NOKOBETEF 6 and 1st European conference on protective clothing held in Stockholm,Sweden, May 7-10, 2000 / [ed] Kalev Kuklane; Ingvar Holmér, Stockholm: Arbetslivsinstitutet , 2000, p. 188-191Conference paper (Refereed)
  • 585.
    Afanasieva, Rallema F
    et al.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Bessanova, Nina A.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistrova, Olga V.
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Burmistrov, Vyacheslav M
    Russian Academy of Medical Sciences, Institute of Labour Medicine, Moscow.
    Holmér, Ingvar
    National Institute for Working Life.
    Kuklane, Kalev
    Luleå tekniska universitet.
    Comparative evaluation of the methods for determining the summary thermal insulation of special cold protective garment ensembles according to the Russian and the international standards1999In: Meditsina truda i promyshlennaia ekologiia, ISSN 1026-9428, Vol. 12, p. 18-24Article in journal (Refereed)
  • 586. Afanu, Eric Kodjo
    et al.
    Mamattah, Raymond Selorm
    Mobile Money Security: A Holistic Approach2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mobile money usage for transactions is steadily growing across Africa with the potential to revolutionize the cash-dominant economy of this continent to be cashless. With the increased use of mobile money services and number of business use cases designed each day, it is imperative to design a holistic approach to mobile money security that will reduce security exposures and prevent fraud, as some mobile money service providers have lost millions of dollars to this growing threat. This research, therefore examines the measures that mobile network operators providing mobile money services can employ to prevent fraud. The study also discusses the mobile money users’ perception about the linkage between mobile phone protection and security of the mobile money service on their phone. The research was a case study of mobile money security in Ghana and used qualitative and quantitative data collected through questionnaires and structured interviews of key staff of the mobile network operator (MNO). Some of the main findings of this research include the general perception that there is no direct linkage between mobile phone protection and mobile money security. It was further identified that one of the major causes of consumer driven fraud is PIN sharing. In addressing mobile money fraud, it is suggested that the service provider should give mobile money security tips to the users at least twice in a year through short message service (SMS) to alert them of ways to enhance the security of their mobile phones

  • 587. Afram, Alexander
    Värme- och ventilationssystem: Den historiska utvecklingen och det arkitektoniska samspelet2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis involves heating and ventilation systems in architecture. The thesis will show how the heating and ventilation systems have looked like and developed overtime. With the help of information developed, three concepts will be created as a result of having combined different concept development methods. The goal is to reach a conclusion on how the optimum house should look like enabling heating and ventilation systems to be easy to maintain and use, and be so energy efficient as possible while fulfilling its purpose. To get a good result all possible factors that in a major or minor scale have impact on the system will be attended. This is for a holistic approach to demonstrate which aspects should get the right measure of perception in the context of building construction projects. Both architecture and internal technology has changed much in recent decades. Within the architecture the rooftops has only decreased, thicker windows and doors are sealed more than ever, the use of mechanized ventilation system is increasingly being introduced and applied, and for the investment costs for a new building to be minimized quick solutions have been figured out. The big picture has unfortunately, because of lack of knowledge, not always been taken into account. The new architecture has caused more problems than good. The low ceiling height impedes the natural air circulation in the room, which contributes to poorer air quality and thickening of the windows and doors makes the inhabitants inherently completely dependent on the capability of the mechanized ventilation to fulfill its purpose. Through three examples of how houses can be built, the report shall give an understanding of the connection between the heating, ventilation and architectural interaction.

  • 588. Afrasiabi Rad, Parvaneh
    Measuring Trust in Online Social Networks: The Effects of Network Parameters on the Level of Trust in Trust Games with Incomplete Information2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to contribute to the methodological foundation of the studies aiming to assess trust between people who interact through Computer Mediated Communication (CMC), specifically those who create a set of online relationships which is commonly called Online Social Networks. The most popular method that is currently employed by researchers in this area is Trust Game, one form of the social dilemma games. The major studies that assess trust in social networks have established results that are mainly formed into hypotheses for the effects of a number of network parameters on the extent to which individuals would place trust on each other. However, hypotheses for the effects of a few number of network parameters is not deducible since the restrictive game-theoretic assumptions that are imposed into the model do not let any such evidence available. In addition, these assumptions inhibit the analysis of the trust situations in a more realistic environment than one in which actors are instructed by the axioms of the Trust Game. One way to relax the game-theoretic assumptions so that the trust situations take place in a more realistic environment is to introduce noise into the context of information transmission. Assuming that the information is not accurately transmitted between different individuals in an online social network makes it possible to argue that the rate of information that is obtained from different sources would influence the level of trust. Here, I conduct a series of computer simulation of a model of Iterated Heterogeneous Trust Games (IHTG), developed by Buskens (1998), adding the assumptions of incomplete information on 6 network structures sampled from Youtube, to investigate the effects of Indegree and Link-strength as the influential network parameters for the noisy environments. The results of regression analysis provide that both Indegree and Link-strength have positive effects on the level of trust, while in the same situation, the positive effects of Link-Strength on trust are more promising and unyielding than those of Indegree. In addition, I argue that the current model by Buskens (1998) carries a deficiency when it is applied to the noisy environments, since it can be fooled by inactive users (i.e. those who have a very low Outdegree compared to a high Indegree) to consider them as influential on the level of trust.

  • 589. Afremo, Sigmund
    et al.
    Egmalm, Anders
    Hortlund, Peter
    Larsson, Peter
    Projektering av Gammelbyvägen. Etapp 1 - Bodens kommun1998Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
  • 590. Afrouz, Firouzeh
    Bank employees' perception about implementation of e-banking in Iran: a comparison study among governmental and private banks2007Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Emergence of IS in banking industry is growing rapidly. In Iran as a developing country with high interest on developing use of IT on different businesses specially in banking industry, functional aspects of service quality in transmission process to e-banking seems to be neglected while technological aspects has been propagated rapidly. The study is trying to enlighten one of the workforce issues in banking industry of Iran with the hope that such an attempt provides ground for more attentions on functional aspects of service quality in e-banking approach by bank managements. Models used to study attitudes and perceptions in psycho –sociology domain has been implemented to study banks employees’ perceptions about implementation of e-banking in Iranian banks. Belief constructs examined as predictor of behavioral intention and adoption of employees with e-banking services and channels. Belief constructs in the model were Relative Advantage of e-banking, Compatibility of it with the working environment, Perceived complexity of implementation of e-banking, Subjective norms effective on their intention, facilitating conditions in their environment and perceived self-efficacy of the employees. PLS(Partial Least Squares) technique was conducted to examine relative importance of beliefs construct from the data which was extracted from 200 questionnaires distributed among employees of two governmental and two private banks on different levels from rank and files. The results showed that relative advantages and perceived self efficacy on both type of banks are significant predictors of behavioral intention, while Subjective norms is another effective construct on governmental banks and perceived Complexity is one of the determinant construct on formation of perception in private banks.

  • 591. Afsahi, Gustav
    Kreativ arrangering med synthesizer: En beskrivning av hur en konventionell synthesizer kan bidra till nyskapande klanger och arrangemang2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 592. Afsahi, Leyli
    Tjejers motivation att bilda band: Ett genusperspektiv2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 593. Afsharipour, Afshin
    et al.
    Afshari, Atefe
    Sahaf Amin, Laila
    E-procurement in atuomotive supply chain of Iran2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Being an important and money-spinning industry for many decades, automotive industry is now facing with several challenges supplemented by global fierce competition. In these circumstances, reducing cost and increasing production development and delivery speed have been identified as practical strategies for survival and growth. Whereas, e-business in general and e- procurement specifically has shown innovative methods and new horizons for implementing those strategies, some developing countries are less prepared for the adoption. Thanks to protectionism, Iranian automotive industry is still enjoying a rather closed market, though sooner or later the latent global challenges will be felt by the market players. In this respect, this thesis is aimed to find out how e-procurement is being used in Iranian automotive supply chain and what benefits and barriers are associated with its implementation. To this end a qualitative approach was used and multiple case studies were conducted. Our finding shows that Iranian automotive supply chain can gain a lot through implementing an integrated and standard e-procurement solution. While, some chronic impediments like technology infrastructure, culture and legal system have to be changed considerably before any pragmatic endeavor.

  • 594.
    Aftab, A.
    et al.
    Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia.
    Ismail, Abdul Razak
    Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia.
    Ibupoto, Zafar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Akeiber, Hussein J.
    Faculty of Mechanical Engineering, Universiti Teknologi Malaysia.
    Malghani, M.G.K.
    Department of Environmental Management and Policy, BUITEMS Quetta, Pakistan.
    Nanoparticles based drilling muds a solution to drill elevated temperature wells: a review2017In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 76, p. 1301-1313Article in journal (Refereed)
    Abstract [en]

    Demand of the oil and gas energy is increasing very drastically. Conventional hydrocarbon reservoirs contain below the sealing cap rock (shale) and easily move towards wellbore are at the depletion stage. Therefore, drilling engineers in collaboration with mud engineers, geologists and geophysicists are looking for innovative materials to drill unconventional hydrocarbons reservoir which are distributed at the basin scale and cannot approach easily. Geo-thermal energy wells and most of unconventional reservoirs are occurred at high pressure high temperature (HPHT) conditions. Conventional micro-macro organic drilling mud additives with heat insulator in nature can minimize efficiency while drilling HPHT wells. Oil-based muds (OBM) are strictly restricted due to high toxic level and poor emulsion stability at HT. However, this review suggests that addition of macro size organic particles and inorganic nanoparticles can enhance rheological performance, reduce filtrate loss volume and improve shale inhibition characteristics of environmental friendly water-based mud (WBM). Despite an impressive amount of experimental work has been done over drilling additives and their effect over rheological and shale inhibition, taking into account their literature review are rare. In addition, there is no review work of the knowledge gained to date. This work will hope fully trigger further development and new research topics in the area of drilling muds system.

  • 595. Aftab, Nauman
    et al.
    Iqbal, Ammar
    3G mobile communication services perspective2006Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The transition from the 2nd Generation (2G) of mobile cellular networks to the 3rd Generation (3G) was motivated by the introduction of multimedia services. More specifically, the convergence of mobile technologies and Internet allows compelling possibilities for future applications due to the new advancement, constantly growing and personalized services in the mobile communication. There are a lot of standards supporting the 3G services and these services make the people's life convenient. Our research objective is to compare the 3G services against 3G standards which we focus on the two most popular standards i.e. WCDMA & CDMA2000. The implementation discussion of one of 3G services which we choose Location Based Services is also our research objective. In order to fulfil the research objective, we firstly choose Mobility category among the 3G services, i.e. Rich Voice, Content Connectivity and Mobility. We believe that Mobility will be the most significant services because of it's personalize nature, e.g. Multimedia Messaging Services (MMS), Customised Infotainment and Location Based Services (LBS). We then compare and analyze Multimedia Messaging Services (MMS), Customised Infotainment and Location Based Services (LBS) against the two 3G standards, i.e.WCDMA & CDMA2000 to show that these two standards are serving these three services. The implementation of Location Based Services is discussed based on the four methods Cell-ID, Observed Timer Difference of Arrival, Wireless Assisted-GPS and Hybrid Technology. Latest and advanced services are only deployed through 3G mobile communication. This study is an effort made to give a deep and detailed understanding of 3G services and implementation of Location Based Service. We think that 3G services on WCDMA network will have edge in future as that it gives the backward compatibility of GSM which deployed around 70% world wide.

  • 596. Afzal, Honey
    EC Adoption and Critical Success Factors of EC in SMEs in Iran2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electronic commerce (e-commerce) is changing the way organizations carry out their responsibilities, cooperate with customers and running their business usually. E-commerce in practice is not only the buying and selling of products via electronic means, it involves all other activities to support the sale process. To take advantage of e-commerce, during the late 1990s many companies expanded their business activities to reach new customers and/or to offer new opportunities to their existing customers. During the same time there has been significant growth of new established companies implementing e- commerce technologies, commonly known as dot-com companies (Lovelock, 2001).However, investigates show that there have been significant breakdowns along with these companies and it is now time to look back and learn from the mistakes of the past. Besides many researches have indicated that significant benefits are achieved by those SMEs that adopt and use Ecommerce in their organizations This survey attempts to explore the importance of an adoption approach for e-commerce technology in Small to Medium Sized Enterprises (SMEs) in Iran. This research hypothesized ten factors as influencing e-commerce adoption significantly in SMEs: eAdvantage, eCost, eTransformation, Size, eProduct, eSupport, ePressure, eCompetiotion, eNnovativeness and eNvolvement. Besides, the research attempts to identify other factor/s rather than these ten factors which are influencing the e-commerce adoption from SMEs point of views. Further, the approach differentiates between adopters and non adopters in terms of the adopted EC as: Non-adopters, Starters and Adopters. The research results point to: (1) Non-adopters: the movement towards Internet and email was dependent on the cost and financial resources for initial investments: (2) Starters: the first stage of EC adoption was dependent on technological support provided by vendors and innovativeness of the manager: (3) Adopters: the adoption of more EC was dependent on e-support, ennovativeness, e-pressure, e-cost and e-advantage. Public awareness and Public purchasing behavior were other significant factors identified by Starters and Adopters. This research also attempts to develop an approach for electronic commerce success. Key factors influencing e-commerce success were identified from literature review and categorized as Internal Drivers/ Obstacles and External Drivers/ Obstacles. In this respect, two studied models by other researchers are examined and the contribution of each factor is re-studied to fit to market of Iran. However, in area of e-commerce adoption Cultural Factors: Public Purchasing Behavior and Public Awareness are recognized as unique factors affecting e-commerce adoption among SMEs in Iran. This survey also found out poor EC Adopted Banking System as an external obstacle in e-commerce success process in Iran.

  • 597. Agah, Mehriar
    Effekter av akupunktur och ultraljud vid triggerpunktrelaterad smärta: en systematisk litteraturstudie2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 598.
    Agarwal, Parminder
    et al.
    Michigan State University.
    Berglund, Kris
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Effect of polymeric additives on calcium carbonate crystallization as monitored by nephelometry2004In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 4, no 3, p. 479-483Article in journal (Refereed)
    Abstract [en]

    The effect of polymaleimide polymers on calcium carbonate crystallization was studied using nephelometry. Induction time and percent growth inhibition were determined for polymeric additives from the nephelometric data. The polymaleimide synthesized by KOH-initiated polymerization exhibited the greatest growth inhibition and longest nucleation time among the polymers investigated. Raman spectroscopy was used to determine the calcium carbonate polymorph formed in the presence of these polymeric additives.

  • 599.
    Agarwal, Parminder
    et al.
    Michigan State University.
    Berglund, Kris
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    In situ monitoring of calcium carbonate polymorphs during batch crystallization in the presence of polymeric additives using Raman spectroscopy2003In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 3, no 6, p. 941-946Article in journal (Refereed)
    Abstract [en]

    Polycarboxylic acids are well-known to affect calcium carbonate crystallization. Agarwal et al. (Ind. Eng. Chem. Res. 2003, in press) reported previously the synthesis of polymaleimide by a variety of techniques and initiators. In the present work, the effect of these polymers on calcium carbonate crystallization was studied by a variety of techniques. Crystallization experiments were carried out in a 1-L LABMAX automated batch reactor, and the concentration of calcium in solution was determined in real time. Raman spectroscopy was used to determine the relative amount of various calcium carbonate polymorphs as the crystallization occurred. However, Raman spectroscopy is a scattering technique, which may make it surface selective, and therefore results from solids may not be representative of bulk of sample. X-ray diffraction (XRD) was used to compare the results obtained by Raman spectroscopy. Peak intensity ratios were used for both Raman spectroscopy and XRD for calibration and measurement purposes. The results obtained by these two techniques for final percent vaterite for calcium carbonate crystallization in the presence of polymeric additives were in agreement within 2%. Therefore, use of Raman spectroscopy for in situ measurement of polymorph composition during calcium carbonate crystallization appears accurate. Scanning electron microscopy (SEM) data were useful in understanding the crystal morphology and to determine crystal size.

  • 600.
    Agarwal, Parminder
    et al.
    Michigan State University.
    Yu, Qiuyue
    Michigan State University.
    Harant, Adam
    Michigan State University.
    Berglund, Kris
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis and characterization of polymaleimide2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 13, p. 2881-2884Article in journal (Refereed)
    Abstract [en]

    Simplified syntheses of polymaleimide employing anionic polymerization (from the melt and from solution) and metal compound-alcohol initiators such as PbO, SnO, tin bis(2-ethyl hexanoate) in the presence of tert-butyl benzyl alcohol are presented. The resulting polymers contain a combination of C-N- and C-C-connected monomers. Preliminary structures of the polymers were determined using NMR spectroscopy. The ratio of C-N- and C-C-connected monomers was determined, and the percentage of C-N-connected monomer units was found to vary from 40 to 80%, with the higher percentage resulting from anionic polymerization. The molecular weights of the polymers, as determined by gel permeation chromatography (GPC) with aqueous mobile phase and sodium polyacrylates standards, ranged between 1100 and 4200 for anionic polymerization and were about 11 500 for metal oxide-alcohol initiated polymerization. Solution-phase properties of the polymaleimides were evaluated by calcium chelation and precipitation inhibition studies. On the basis of the measured properties of these polymers, they are proposed as biodegradable, low-impact detergent additives to substitute currently used compounds.

9101112131415 551 - 600 of 64687
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf