du.sePublications
Change search
Refine search result
343344345346347348349 17251 - 17300 of 17765
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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.
  • 17251.
    Zhao, Xiaoyun
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Carling, Kenneth
    Dalarna University, School of Technology and Business Studies, Statistics.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Human Geography. Dalarna University, School of Technology and Business Studies, Information Systems.
    Residential planning, driver mobility and CO2 emission2016Report (Other academic)
    Abstract [en]

    In a city there are hotspots that attract the citizens and most of the transportation in the city arises when citizens move between their residence and the hotspots. However, the evaluation between energy-efficient mobility and urban residential planning has been found to be rather weak. In this paper, we propose an ex-ante evaluation method to quantify the impacts in terms of CO2 emissions induced by intra-urban car mobility due to different residential plans implemented at various urban areas. The method is illustrated by a Swedish midsize city which is presently preoccupied with urban planning of new residential areas in response to substantial population growth due to immigration. On average, the CO2 emissions increase from the continued urban core area (CUCA) to the suburban polycentric area (SPA) to the edge urbanization area (EUA), EUA is almost 3 times more than CUCA. The average travel distances also increase in the same sequence, the overall increase is more than 4 times. Apartment buildings could be more effective in meeting residential needs and mitigating CO2 emissions than dispersed single-family houses.

  • 17252.
    Zhao, Xiaoyun
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Carling, Kenneth
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Residential planning, driver mobility and CO2 emission: a microscopic look at Borlänge in Sweden2017In: European Planning Studies, ISSN 0965-4313, E-ISSN 1469-5944, Vol. 25, no 9, p. 1597-1614Article in journal (Refereed)
    Abstract [en]

    In a city there are hotspots that attract citizens, and most of the transportation arises when citizens move between their residence and primary destinations (i.e. hotspots). However, an ex ante evaluation of energy-efficient mobility and urban residential planning has seldom been conducted. Therefore, this paper proposes an ex ante evaluation method to quantify the impacts, in terms of CO2 emissions induced by intra-urban car mobility, of residential plans for various urban areas. The method is illustrated in a case study of a Swedish midsize city, which is presently preoccupied with urban planning of new residential areas in response to substantial population growth due to immigration. In general, CO2 emissions increase from the continued urban core area (CUCA), to the sub-polycentric area (SPA), to the edge urbanization area (EUA), where CO2 emission of EUA is twice that of the CUCA. The average travel distances also increase in the same pattern, though the relative increase is more than four times. Apartment buildings could be more effective in meeting residential needs and mitigating CO2 emissions than dispersed single-family houses. 

  • 17253.
    Zhao, Xiaoyun
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Rebreyend, Pascal
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Information Systems. Dalarna University, School of Technology and Business Studies, Human Geography.
    Does road network density matter in optimally locating facilities?2015Report (Other (popular science, discussion, etc.))
    Abstract [en]

    Optimal location on the transport infrastructure is the preferable requirement for many decision making processes. Most studies have focused on evaluating performances of optimally locate p facilities by minimizing their distances to a geographically distributed demand (n) when p and n vary. The optimal locations are also sensitive to geographical context such as road network, especially when they are asymmetrically distributed in the plane. The influence of alternating road network density is however not a very well-studied problem especially when it is applied in a real world context. This paper aims to investigate how the density level of the road network affects finding optimal location by solving the specific case of p-median location problem. A denser network is found needed when a higher number of facilities are to locate. The best solution will not always be obtained in the most detailed network but in a middle density level. The solutions do not further improve or improve insignificantly as the density exceeds 12,000 nodes, some solutions even deteriorate. The hierarchy of the different densities of network can be used according to location and transportation purposes and increase the efficiency of heuristic methods. The method in this study can be applied to other location-allocation problem in transportation analysis where the road network density can be differentiated. 

  • 17254.
    Zhao, Xiaoyun
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Rebreyend, Pascal
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Håkansson, Johan
    Dalarna University, School of Technology and Business Studies, Information Systems. Dalarna University, School of Technology and Business Studies, Human Geography.
    How does the complexity of a road network affect optimal facility locations?2015Report (Other academic)
    Abstract [en]

    The road network is a necessary component in transportation. It facilitiesspatial movements of people and goods, and it also influences the optimal locations of facilities that usually serve as destinations of the movements. To fulfill the transportation needs and to adapt to the facility development, the road network is often organized hierarchically and asymmetrically with various road levels and spatial structures. The complexity of the road network increases along with the increase of road levels and spatial structures. However, location models locate facilities on a given road network, usually the most complex one, and the influence from the complexity of road network in finding optimal locations is not well-studied. This paper aims to investigate how the complexity of a road network affects the optimal facility locations by applying the widely-applied p-median model. The main result indicates that an increase in road network complexity, up to a certain level, can obviously improve the solution, and the complexity beyond that level does not always lead to better solutions. Furthermore, the result is not sensitive to the choice of algorithms. In a specific case study, a detailed sensitivity analysis of algorithm and facility number further provides insight into computation complexity and location problems from intra-urban to inter-urban.

  • 17255. Zhao, Xudong
    et al.
    Zhang, Xingxing
    Solar Photovoltaic/Thermal Technologies and their Application in Building Retrofitting2013In: Nearly Zero Energy Building Refurbishment: A Multidisciplinary Approach / [ed] Pacheco et al, Springer, 2013, p. 615-658Chapter in book (Refereed)
  • 17256. Zhao, Xudong
    et al.
    Zhang, Xingxing
    De Montfort University.
    Riffat, Saffa B.
    Su, Yaxin
    Theoretical study of the performance of a novel PV/e roof module for heat pump operation2011In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 52, no 1, p. 603-614Article in journal (Refereed)
    Abstract [en]

    In this paper, a novel PV/e roof module was designed to act as the roof element, electricity generator and the evaporator of a heat pump system. The modules, in conjunction with a heat pump, are able to provide heat and power supply to buildings with an enhanced efficiency. Energy profiles of the PV/e modules and modules-based heat pump system were analysed and temperature distribution across the module layers was studied. It was found that the PV/e roof modules-based heat pump system can achieve significant improvement in thermal and electrical efficiencies. Variation of the system efficiencies (thermal, electrical and total) with a number of factors, i.e., top cover, PV cells, evaporation and condensation temperature of the heat pump was investigated, which led to suggestion of the optimised system configuration and operating conditions. The study indicated that the combined system should operate at 10 °C of evaporation and 60 °C of condensation temperature. Borosilicate as a top cover has better thermal performance than polycarbonate and glass; whilst the mono-crystalline photovoltaic cells are of higher electrical efficiency over the poly-crystalline and thin-films. Under a typical Nottingham (UK) operating condition, the modules would achieve 55% of thermal efficiency and 19% of electrical efficiency, while the module-based heat pump system would have an overall efficiency of above 70%. It was also addressed that the integration of the PV cells and evaporation coil into a prefabricated roof would lead to large saving in both capital and running costs over separate arrangements of PV, heat pump and roof structure.

  • 17257.
    Zhong, Shengtong
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    The remote control of mobile robot on the Internet2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    During last decades, the Internet teleobotics has been growing at an enormous rate due to the rapid improvement of Internet technology. This paper presents the internet-based remote control of mobile robot. To face unpredictable Internet delays and possible connection rupture, a direct continuous control based teleoperation architecture with “Speed Limit Module” (SLM) and “Delay Approximator” (DA) is proposed. This direct continuous control architecture guarantees the path error of the robot motion is restricted within the path error tolerance of the application. Experiment results show the feasibility and effectiveness of this direct Internet control architecture in the real Internet environment.

  • 17258. Zhou, Bin
    et al.
    Bentham, James
    Di Cesare, Mariachiara
    Bixby, Honor
    Danaei, Goodarz Danaei
    Hajifathalian, Kaveh
    Taddei, Cristina
    Carrillo-Larco, Rodrigo M
    Forsner, Maria
    Dalarna University, School of Education, Health and Social Studies, Caring Science/Nursing.
    Ezzati, Majid
    Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants2018In: International Journal of Epidemiology, ISSN 0300-5771, E-ISSN 1464-3685, Vol. 47, no 3, p. 872-883Article in journal (Refereed)
    Abstract [en]

    Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.

    Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20–29 years to 70–79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.

    Results: In 2005–16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.

    Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

  • 17259. Zhou, Bin
    et al.
    Ezzati, Majid
    Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants2017In: The Lancet, ISSN 0140-6736, E-ISSN 1474-547X, Vol. 389, no 10064, p. 37-55Article in journal (Refereed)
    Abstract [en]

    Background

    Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher.

    Methods

    For this analysis, we pooled national, subnational, or community population-based studies that had measured blood pressure in adults aged 18 years and older. We used a Bayesian hierarchical model to estimate trends from 1975 to 2015 in mean systolic and mean diastolic blood pressure, and the prevalence of raised blood pressure for 200 countries. We calculated the contributions of changes in prevalence versus population growth and ageing to the increase in the number of adults with raised blood pressure.

    Findings

    We pooled 1479 studies that had measured the blood pressures of 19·1 million adults. Global age-standardised mean systolic blood pressure in 2015 was 127·0 mm Hg (95% credible interval 125·7–128·3) in men and 122·3 mm Hg (121·0–123·6) in women; age-standardised mean diastolic blood pressure was 78·7 mm Hg (77·9–79·5) for men and 76·7 mm Hg (75·9–77·6) for women. Global age-standardised prevalence of raised blood pressure was 24·1% (21·4–27·1) in men and 20·1% (17·8–22·5) in women in 2015. Mean systolic and mean diastolic blood pressure decreased substantially from 1975 to 2015 in high-income western and Asia Pacific countries, moving these countries from having some of the highest worldwide blood pressure in 1975 to the lowest in 2015. Mean blood pressure also decreased in women in central and eastern Europe, Latin America and the Caribbean, and, more recently, central Asia, Middle East, and north Africa, but the estimated trends in these super-regions had larger uncertainty than in high-income super-regions. By contrast, mean blood pressure might have increased in east and southeast Asia, south Asia, Oceania, and sub-Saharan Africa. In 2015, central and eastern Europe, sub-Saharan Africa, and south Asia had the highest blood pressure levels. Prevalence of raised blood pressure decreased in high-income and some middle-income countries; it remained unchanged elsewhere. The number of adults with raised blood pressure increased from 594 million in 1975 to 1·13 billion in 2015, with the increase largely in low-income and middle-income countries. The global increase in the number of adults with raised blood pressure is a net effect of increase due to population growth and ageing, and decrease due to declining age-specific prevalence.

    Interpretation

    During the past four decades, the highest worldwide blood pressure levels have shifted from high-income countries to low-income countries in south Asia and sub-Saharan Africa due to opposite trends, while blood pressure has been persistently high in central and eastern Europe.

    Funding

    Wellcome Trust.

  • 17260.
    Zhou, Nian
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Influence of grinding operations on surface integrity and chloride induced stress corrosion cracking of stainless steels2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Stainless steels were developed in the early 20th century and are used where both the mechanical properties of steels and corrosion resistance are required. There is continuous research to allow stainless steel components to be produced in a more economical way and be used in more harsh environments. A necessary component in this effort is to correlate the service performance with the production processes.

    The central theme of this thesis is the mechanical grinding process.  This is commonly used for producing stainless steel components, and results in varied surface properties that will strongly affect their service life. The influence of grinding parameters including abrasive grit size, machine power and grinding lubricant were studied for 304L austenitic stainless steel (Paper II) and 2304 duplex stainless steel (Paper I). Surface integrity was proved to vary significantly with different grinding parameters. Abrasive grit size was found to have the largest influence. Surface defects (deep grooves, smearing, adhesive/cold welding chips and indentations), a highly deformed surface layer up to a few microns in thickness and the generation of high level tensile residual stresses in the surface layer along the grinding direction were observed as the main types of damage when grinding stainless steels. A large degree of residual stress anisotropy is interpreted as being due to mechanical effects dominating over thermal effects.

    The effect of grinding on stress corrosion cracking behaviour of 304L austenitic stainless steel in a chloride environment was also investigated (Paper III). Depending on the surface conditions, the actual loading by four-point bend was found to deviate from the calculated value using the formula according to ASTM G39 by different amounts. Grinding-induced surface tensile residual stress was suggested as the main factor to cause micro-cracks initiation on the ground surfaces. Grinding along the loading direction was proved to increase the susceptibility to chloride-induced SCC, while grinding perpendicular to the loading direction improved SCC resistance.

    The knowledge obtained from this work can provide a reference for choosing appropriate grinding parameters when fabricating stainless steel components; and can also be used to help understanding the failure mechanism of ground stainless steel components during service.

  • 17261.
    Zhou, Nian
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH, Yt- och korrosionsvetenskap.
    Surface integrity and corrosion behavior of stainless steels after grinding operations2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Stainless steels are widely used in applications where both the mechanical properties of steels and high corrosion resistance are required. There is continuous research to enable stainless steel components to be produced in a more economical way and be used in more harsh environments. A way to achieve this is to correlate the service performance with the production processes.

    The central theme of this thesis is surface integrity and corrosion, especially the stress corrosion cracking behavior, after grinding processes. Controlled grinding parameters, including abrasive grit size, machine power and grinding lubricant, were used and the resulting surface properties studied for austenitic 304L and duplex 2304 stainless steels. The abrasive grit size effect was found to have a larger influence. Surface defects, a highly deformed surface layer and the generation of a high level surface tensile residual stresses along the grinding direction were observed as the main types of damage. 

    The effect of grinding on stress corrosion cracking behavior of austenitic 304L, ferritic 4509 and duplex 2304 stainless steels in chloride-containing environments was also investigated.  The abrasive grit size effect on corrosion behavior for the three grades was compared. Grinding-induced surface tensile residual stress was suggested as the main factor to cause micro-cracks on the ground surface for 304L and 2304; for 4509, grinding-induced grain fragmentation was considered as the main factor for the initiation of extensive micro-pits. For duplex 2304, the microstructure and micro-notches in the as-ground surface also had significant influence. Depending on the surface conditions, the actual loading by four-point bending was found to deviate from the calculated value using the formula according to ASTM G39 by different amounts. The knowledge obtained from this work can provide guidance for choosing appropriate stainless steel grades and grinding parameters; and can also be used to help understanding the failure mechanism of ground stainless steel components during service.

  • 17262.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Lin Peng, Ru
    Linköping University.
    Pettersson, Rachel
    Jernkontoret, KTH.
    Surface characterization of austenitic stainless steel 304L after different grinding operations2017In: International Journal of Mechanical and Materials Engineering, ISSN 2198-2791, Vol. 12, no 6Article in journal (Refereed)
    Abstract [en]

    Background: The austenitic stainless steel 304L is widely used as a structural material for which the finished surface has significant effect on the service performance. A study of the grinding process with regard to the quality of the ground surfaces is therefore interesting from the point of view of both industrial application and scientific research.

    Method: This work investigates the influence of grinding parameters including abrasive grit size, machine power, and grinding lubrication on the surface integrity of the austenitic stainless steel 304L. The induced normal grinding force, grinding surface temperature, metal removal rate, and surface property changes have been investigated and compared.

    Results and Conclusion: Using grinding, lubrication significantly enhanced the metal removal rate. Surface defects (deep grooves, smearing, adhesive chips, and indentations), a highly deformed thin surface layer up to a few microns in thickness, and high surface tensile residual stresses parallel to the grinding direction have been observed as the main damage induced by the grinding operations. Surface finish and deformation were found to be improved by using smaller abrasive grits or by using lubrication during grinding. Increasing the machine power increased surface deformation while reducing surface defects. The results obtained can provide a reference for choosing appropriate grinding parameters when machining 304L; and can also help to understand the failure mechanism of ground austenitic stainless steel components during service.

  • 17263.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Lin Peng, Ru
    Linköping University.
    Pettersson, Rachel
    Jernkontoret, KTH.
    Schönning, Mikael
    Avesta Research Center - Outokumpu Stainless AB.
    Residual stress in stainless steels after surface grinding and its effect on chloride induced SCC2016In: Materials Research Proceedings: Residual Stresses 2016: ICRS-10, 2016, p. 289-294Conference paper (Refereed)
    Abstract [en]

    The induced residual stresses in stainless steels as a consequence of surface grinding as well as their influence on the chloride induced stress corrosion cracking (SCC) susceptibility have been investigated. Three types of materials were studied: 304L austenitic stainless steel, 4509 ferritic stainless steel and 2304 duplex stainless steel. Surface grinding using 60# and 180# grit size abrasives was performed for each material. Residual stress depth profiles were measured using X-ray diffraction. The susceptibility to stress corrosion cracking was evaluated in boiling MgCl2 according to ASTM G36. Specimens were exposed without applying any external loading to evaluate the risk for SCC caused solely by residual stresses. Induced residual stresses and corrosion behavior were compared between the austenitic, ferritic and duplex stainless steels to elucidate the role of the duplex structure. For all materials, the grinding operation generated tensile residual stresses in the surface along the grinding direction but compressive residual stresses perpendicular to the grinding direction. In the subsurface region, compressive stresses in both directions were present. Micro-cracks initiated due to high grinding-induced tensile residual stresses in the surface layer were observed in austenitic 304L and duplex 2304, but not in the ferritic 4509. The surface residual stresses decreased significantly after exposure for all specimens.

  • 17264.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Lin Peng, Ru
    Linköping University.
    Schönning, Mikael
    Avesta Research Center–Outokumpu Stainlelss AB.
    Pettersson, Rachel
    Jernkontoret, KTH.
    SCC of 2304 duplex stainless steel - microstructure, residual stress and surface grinding effects2017In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 10, no 3, article id 221Article in journal (Refereed)
    Abstract [en]

    The influence of surface grinding and microstructure on chloride induced stress corrosion cracking (SCC) behavior of 2304 duplex stainless steel has been investigated. Grinding operations were performed both parallel and perpendicular to the rolling direction of the material. SCC tests were conducted in boiling magnesium chloride according to ASTM G36; specimens were exposed both without external loading and with varied levels of four-point bend loading. Residual stresses were measured on selected specimens before and after exposure using the X-ray diffraction technique. In addition, in-situ surface stress measurements subjected to four-point bend loading were performed to evaluate the deviation between the actual applied loading and the calculated values according to ASTM G39. Micro-cracks, initiated by grinding induced surface tensile residual stresses, were observed for all the ground specimens but not on the as-delivered surfaces. Loading transverse to the rolling direction of the material increased the susceptibility to chloride induced SCC. Grinding induced tensile residual stresses and micro-notches in the as-ground surface topography were also detrimental.

  • 17265.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Peng, R. L.
    Pettersson, R.
    Surface integrity of 2304 duplex stainless steel after different grinding operations2016In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 229, p. 294-304Article in journal (Refereed)
    Abstract [en]

    Surface integrity has significant effect on service performance of a component. In this study, the evolution of the surface and sub-surface changes induced by grinding duplex stainless steel (DSS) 2304 was studied with regard to the residual stress, the microstructure, surface roughness and surface defects. The results provide insights into the effect of abrasive grit size, grinding force and lubrication on the surface integrity. The abrasive grit size was found to have the largest influence. Surface defects, a highly deformed surface layer and the generation of tensile residual stresses along the grinding direction have been found to be the main types of damage induced by the grinding operation. Residual stresses induced by mechanical effects dominate over thermal effects in this study. The results obtained can be used to understand the contribution of surface condition and residual stress on failure of duplex stainless steels in service by fatigue or stress corrosion cracking.

  • 17266.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Pettersson, R.
    Schönning, M.
    Peng, R. L.
    Influence of surface grinding on corrosion behavior of ferritic stainless steels in boiling magnesium chloride solution2018In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 69, no 11, p. 1560-1571Article in journal (Refereed)
    Abstract [en]

    The influence of grinding operations on surface properties and corrosion behavior of a ferritic stainless steel (FSS), EN 1.4509, has been investigated and limited comparisons also made to the grade EN 1.4622. Surface grinding was performed along the rolling direction of the material. Corrosion tests were conducted in boiling magnesium chloride solution according to ASTM G36; specimens were exposed both without external loading and under four‐point bend loading. The surface topography and cross‐section microstructure before and after exposure were investigated, and residual stresses were measured on selected specimens before and after corrosion tests using X‐ray diffraction. In addition, in situ surface stress measurements were performed to evaluate the actual surface stresses of specimens subject to four‐point bend loading according to ASTM G39. Micro‐pits showing branched morphology initiated from the highly deformed ground surface layer which contained fragmented grains, were observed for all the ground specimens but not those in the as‐delivered condition. Grain boundaries under the surface layer appeared to hinder the corrosion process. No macro‐cracking was found on any specimen after exposure even at high calculated applied loads.

  • 17267.
    Zhou, Nian
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. KTH.
    Pettersson, Rachel
    KTH; Jernkontoret.
    Peng, Ru Lin
    Linköping universitet.
    Schonning, Mikael
    Outokumpu Stainless AB, Avesta.
    Effect of surface grinding on chloride induced SCC of 304L2016In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 658, p. 50-59Article in journal (Refereed)
    Abstract [en]

    The effect of surface grinding on the stress corrosion cracking (SCC) behavior of 304L austenitic stainless steel in boiling magnesium chloride has been investigated. SCC tests were conducted both without external loading and with varied levels of four-point bend loading for as-delivered material and for specimens which had been ground parallel or perpendicular to the loading direction. Residual stresses due to the grinding operation were measured using the X-ray diffraction technique. In addition, surface stress measurements under applied load were performed before exposure to evaluate the deviation between actual applied loading and calculated values according to ASTM G39. Micro-cracks initiated by a high level of tensile residual stress in the surface layer were observed for all the ground specimens but not those in the as-delivered condition. Grinding along the loading direction increased the susceptibility to chloride induced SCC; while grinding perpendicular to the loading direction improved SCC resistance. Surface tensile residual stresses were largely relieved after the initiation of cracks. (C) 2016 Elsevier B.V. All rights reserved.

  • 17268. Zhu, Chaoyi
    et al.
    Gluesenkamp, Kyle R
    Yang, Zhiyao
    Blackman, Corey
    Dalarna University, School of Technology and Business Studies, Energy Technology. SaltX Technology; Mälardalens högskola.
    Unified thermodynamic model to calculate COP of diverse sorption heat pump cycles: Adsorption, absorption, resorption, and multistep crystalline reactions2019In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 99, p. 382-392Article in journal (Refereed)
    Abstract [en]

    A straightforward thermodynamic model is developed in this work to analyze the efficiency limit of diverse sorption systems. A method is presented to quantify the dead thermal mass of heat exchangers Solid and liquid sorbents based on chemisorption or physical adsorption are accommodated. Four possible single-effect configurations are considered: basic absorption or adsorption (separate desorber, absorber, condenser, and evaporator); separate condenser/evaporator (two identical sorbent-containing reactors with a condenser and a separate direct expansion evaporator); combined condenser/evaporator (one salt-containing reactor with a combined condenser/evaporator module); and resorption (two sorbent-containing reactors, each with a different sorbent). The analytical model was verified against an empirical heat and mass transfer model derived from component experimental results. It was then used to evaluate and determine the optimal design for an ammoniate salt-based solid/gas sorption heat pump for a space heating application. The effects on system performance were evaluated with respect to different working pairs, dead thermal mass factors, and system operating temperatures. The effect of reactor dead mass as well as heat recovery on system performance was also studied for each configuration. Based on the analysis in this work, an ammonia resorption cycle using LiCl/NaBr as the working pair was found to be the most suitable single-effect cycle for space heating applications. The maximum cycle heating coefficient of performance for the design conditions was 1.50 with 50% heat recovery and 1.34 without heat recovery.

    The full text will be freely available from 2020-06-30 23:36
  • 17269.
    Zhu, Fangqun
    et al.
    Dalarna University, School of Technology and Business Studies, Economics.
    Sun, Pei
    Dalarna University, School of Technology and Business Studies, Economics.
    The Relationship between Transport Infrastructure and Economic Growth: An Empirical Analysis Comparing Developing and Developed Countries2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Gross domestic product (GDP) is generally considered as the most important index and comprehensive measure of the size of economy. This paper investigates empirically the relationship between transport infrastructure (focus on highways) and GDP growth based on a production function approach. The physical stocks of transport infrastructure were used instead of monetary data to measure public capital together with several other variables (labor and private capital) that were hypothesized to affect economic growth. Then we explore a number of subsequent studies that use panel data covering the period between 1992 and 2004. An investigation was done to compare developed countries and developing countries. Results indicate that physical units are positively and significantly related to economic growth. Furthermore there was an interesting finding that the output elasticity with respect to physical units for developed countries is higher than developing countries.

  • 17270. Zhu, H.
    et al.
    Duncan, Tara
    Dalarna University, School of Technology and Business Studies, Tourism Studies.
    Tucker, H.
    The issue of translation during thematic analysis in a tourism research context2019In: Current Issues in Tourism, ISSN 1368-3500, E-ISSN 1747-7603, Vol. 22, no 4, p. 415-419Article in journal (Refereed)
    Abstract [en]

    This research note discusses issues with translation of non-English text during qualitative analysis in tourism research using examples from the newly emergent phenomenon of Chinese working holidaymakers in New Zealand. In particular, this note highlights an additional translation step in the thematic analysis process with non-English interview quotes and excerpts. This note argues the merit of researchers’ dual role as researcher/translator and discusses how researchers can undertake translation in cross-language research to maintain the rigour of qualitative tourism research. © 2017 Informa UK Limited, trading as Taylor & Francis Group

  • 17271.
    Zidane, Mouna
    Dalarna University, School of Education, Health and Social Studies, Sociology.
    En kvalitativ studie om vuxna invandrares tillägnande och bruk av svenska språket.: De vuxna invandrares upplevelser av tillägnande och bruk av svenska språket med utgångspunkt i möjligheter och begränsningar i deras kommunikationsmöjligheter på målspråket i det nya landet.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The study is a qualitative study aimed at examining foreign born adult immigrants access to the Swedish language and its commitment to communication with the population in the new country. The study tries to find a connection between the experienced immigrants' perceived communication in Sweden, their access to and use of the Swedish language in the social context they end up in and the attitude they show towards the Swedish language and its learning. Half of the surveyors, namely the women, had experienced an appreciated access and entry into the Swedish language. All women witness a fairly diverse access to the Swedish language and mention the family, cousins, partners, work colleagues, and the neighborhood as an example. The school was considered the most important context that offered contact with other immigrants in the target language. The adult immigrant men did not appreciate their access to the Swedish language and found that they did not have favorable opportunities to come into contact with it. They mention the contact with friends from their home country as a direct reason why they have not had access to the Swedish language and learned it. The men showed a negative attitude towards language learning, which is linked to no significant contact with the Swedish language in the first instance. A high degree of closeness and cohesion seem to be important factors that have influenced men's access to and use of the Swedish language

  • 17272.
    Zidén, Kalle
    Dalarna University, School of Education, Health and Social Studies, Educational Work.
    Teknikämnets tradition i Skolverkets dokument och filmer: En problematisering med alternativa perspektiv2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    De historiskt dominerande inslagen i teknikundervisningen på svenska grundskolor har varit

    att tillverka produkter genom problemlösande processer, lära sig om konstruktioner samt

    bekanta sig med redskap, material och tillverkningsprocesser. Det traditionella

    undervisningsinnehållet benämns som artefaktfokuserat, där artefakterna ses som tillverkade

    materiella föremål, och har utifrån sin dominans inneburit en didaktisk utmaning då mer

    abstrakta fenomen avsetts behandlas. Då det svenska samhället utvecklats från ett

    industrisamhälle till ett tjänstesamhälle, samtidigt som eleverna idag i stor utsträckning finner

    undervisningen som orelevant, kan det förstås som intressant att titta närmare på hur ämnet

    kommuniceras. Detta då det visat sig att flest lärare menar att de utgår från det centrala

    innehållet i kursplanen när de planerar och genomför sin undervisning.

    Mot denna bakgrund undersöker detta examensarbete de exempel på

    undervisningsinnehåll som återges i Skolverkets styrdokument, fördjupningstexter och filmer

    som kommunicerar teknikämnet. Syftet är att redogöra för hur stor andel av de identifierade

    exemplen på undervisningsinnehåll som är av den traditionella typen. Vidare avses andra

    typer av artefakter att identifieras och kategoriseras.

    Urvalet av material studeras utifrån en kvantitativ innehållsanalys som bearbetar det

    faktiska innehållet med hjälp av en ram bestående av definierade artefakttyper. Dessa

    klassificerar och kategoriserar de exempel som identifieras i materialet.

    Genom de 746 exempel på undervisningsinnehåll som identifierats, visar det sig att

    78% av dessa är av den traditionella typen. Vidare ses mönster där de tillverkade materiella

    föremålen tilldelas centrala platser och där andra icke fysiska verktyg ses som hjälpmedel att

    utveckla de förstnämnda. Vid studier av enbart det centrala innehållet bekräftas denna

    dominans i avseende på antal samt att de tillverkade materiella föremålen har en central plats.

    Andra artefakttyper som identifieras i materialet är naturföremål, cyborger och

    sociokulturella artefakter.

    Utifrån resultatet av undersökningen och mot bakgrunden av den teori och de

    definitioner som utformat ramen presenteras alternativa perspektiv. Dessa vänder på

    förhållandet så att mer abstrakta innehåll ges centrala platser vilket skapar alternativa

    sammanhang att diskutera teknik utifrån. Dessa alternativ kan verka för en diskussion kring

    vad teknikundervisningen i den svenska grundskolan kan innehålla och utformas efter. Inte

    för att det ena skulle vara mer rätt än det andra men om fler perspektiv synliggörs ges

    förutsättningar till att på ett reflekterat sätt utforma den undervisning som eftersträvas. Kort

    och gott kan kunskapen om fler perspektiv skapa förutsättningar för att beslut om

    undervisningens innehåll fattas utifrån kunskaper om teorier och definitioner, inte utifrån

    traditioner, föreställningar och känslor.

  • 17273.
    Zidén, Karl
    Dalarna University, School of Technology and Business Studies, Industrial Engineering and Management.
    Strategi och modell för underhållsverksamhet under avveckling: En studie av underhållsverksamheten på tunnelbanevagn modell C62014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Många industriföretag måste arbeta med att reducera sina kostnader för att överleva på

    marknaderna som blir allt hårdare. Samtidigt har medvetenheten om fördelarna med att arbeta

    för att förlänga livslängden på det som underhålls blivit det företagen arbetar mot.

    Utvecklingen och tiden leder till att introduceringar och avvecklingar genomförs men i

    dagsläget finns inga tydliga teorier och modeller för hur dessa bör genomföras i ett

    underhållsperspektiv.

    Under en period över 2017-18 ska 88 stycken tunnelbanevagnar av modell C6, vilka används i

    Stockholms tunnelbanenätverk, avvecklas. Detta beror av planerade inleveranser av en ny

    modell vilken benämns C30. Då tidigare avvecklingar genomförts har indikationer från

    inblandade getts gällande att de kunnat ske på smartare sätt. Eftersom tid finns innan

    avvecklingen påbörjas ges möjlighet till att se över hur den bör utformas. Vid utformningen

    finns tre grundpelare vilka måste beakta och de är; säkerheten, driftsäkerheten och kostnaden.

    Syftet med arbetet är dels att motivera för vilken strategi som ska väljas gällande underhållet

    under perioden. Vidare ska en avvecklingsmodell arbetas fram vilken svarar mot hur antalet

    vagnar ska reduceras. Resultatet av studien förväntas vidare vara applicerbar på nästa

    vagnsmodell samt bidra till ett generellt bidrag till det förhållande mellan avveckling och

    underhåll som idag saknar teorier och modeller.

    De undersökningar som bedrivits resulterade i att underhållsplanens rådande utformning inte

    ska frångås. Istället ska den modell som arbetats fram styra det urval som görs varje gång ett

    antal vagnar ska tas ur bruk.

    Den modell som arbetats fram testades på historiska data för att simulera en avveckling

    baserad på data fri från antaganden. Resultatet blev att en tredjedel av kostnaden under

    perioden kunde sparas, närmare 2,2 miljoner kronor.

    Viss indikation gavs gällande att driftsäkerheten genom urvalet kunde höjas. Vidare tar

    modellen hänsyn till många aspekter vilka inte alltid är lätta att värdesätta samt att den är

    anpassningsbar till de förutsättningar gällande avvecklingen som kan förändras.

  • 17274.
    Zielinski, Antoni
    Dalarna University, School of Humanities and Media Studies, Moving Image Production.
    Filmklipparens arbetsprocess i Hollywood och Europa: Undersökning av möjliga skillnader och likheter i filmklipparens arbetsprocess i Hollywood och Europa2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetsprocessen har förändrats under filmhistoriens gång, delvis på grund av teknologiska framsteg, som till exempel bytet till digitala filmklippningsverktyg. Hur filmklippningsprocessen ser ut, skiljer sig mellan filmklippare, men kan man även finna skillnader mellan olika regioner?

    Den här uppsatsen undersöker ifall det finns några likheter och skillnader mellan arbetsprocessen för filmklippning i Europa och Hollywood. Undersökningen genomförs genom en kvalitativ analys, där material samlas in från diverse påståenden från filmklippare i litteratur, samt från kvalitativa intervjuer som genomförs med filmklipparna Martin Hunter och Michal Leszczylowski.

    Resultatet pekar på att det finns både likheter och skillnader mellan de två regionerna. De båda regionernas arbetsprocess har påverkats av bytet till digital filmklippning. Deras arbetsuppgifter liknar på många sätt varandra, med det skiljer sig hur dessa arbetsuppgifter utförs. I Hollywood kan det ofta skådas mer resurser tillgängliga för filmklipparen, men samtidigt också mer inflytande från producenter och filmstudior på deras arbete. Däremot har filmklipparen i Europa ett starkare samarbete med regissören, och enligt dem är deras huvudsakliga uppgift att arbeta fram regissörens vision av filmen.

  • 17275.
    Zilliacus, Harriet
    et al.
    University of Helsinki.
    Paulsrud, BethAnne
    Dalarna University, School of Humanities and Media Studies, English. Stockholm University.
    Holm, Gunilla
    University of Helsinki.
    Essentializing vs. non-essentializing students' cultural identities: curricular discourses in Finland and Sweden2017In: Journal of Multicultural Discourses, ISSN 1744-7143, E-ISSN 1747-6615, no 2, p. 166-180Article in journal (Refereed)
    Abstract [en]

    This article examines how students' cultural identities are discursively constructed in the Finnish and Swedish national curricula for the compulsory school. The aim is to illuminate the manifold discourses on cultural identity which prevail within Nordic educational policy. The study employs a critical multicultural education and postcolonial perspective with a particular focus on essentialist and non-essentialist views of identity in the curricular discourses. Through discourse analysis, key terms such as 'cultural identity' and 'multicultural identity' as well as different aspects of cultural identities such as language, gender and religion are investigated. The results show diverging discourses, with distinct differences in their explicitness and implicitness in the two countries. A clear effort to see all students as having multi-layered and multicultural identities is evident in the Finnish curricular discourse whereas a more essentializing discourse emerges in the Swedish curriculum. We conclude with a discussion on the importance of addressing policy discourses on students' cultural identities in order to ensure non-essentialist and socially just teaching and educational practice.

  • 17276.
    Zimmergren, Anette
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Hur företagsledare bidrar till kreativa tillvägagångssätt vid problemlösande för sina anställda2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Fokuset i studien ligger på det transformativa ledarskapet och chefernas möjligheter till de anställda att göra karriär och utvecklas i arbetet. Det har länge funnits bland annat två stora ledarskapstyper, transaktionellt och transformativt ledarskap. Efter att ha läst flera vetenskapliga artiklar inom området transformativt ledarskap och skapande av kreativitet, har det konstaterats att det finns begränsad empirisk forskning inom området. För att ta reda på hur empirin ser ut har intervjuer genomförts med tre transformativa chefer från tre olika företag och två av deras anställda för att se hur cheferna ger möjligheter till de anställda att göra karriär och utvecklas i arbetet. Med hjälp av intervjuerna som genomförts går det att se hur ledarskapet fungerar i praktiken och hur väl det stämmer överens med tidigare forskning.

    Resultatet i studien visar att mycket av chefernas tid går till det transaktionella ledarskapet eftersom de vill ha kontroll över vad de anställda gör. Dock är det en svår balansgång för företagen att hålla mellan att vara transaktionella och transformativa, de ska både kunna ge eget ansvar samt ha kontroll. Däremot är det en konkurrensfördel som cheferna har bland traditionella företag på konkurrensutsatta marknader då de ger utrymme till de anställda att utvecklas genom att gå på utbildningar. Detta ökar de anställdas engagemang vilket är kopplat till företagets produktivitet.

    Skulle de anställda behöva mer hjälp än den stöttning som de får, finns cheferna där och coachar dem på rätt spår igen samt att cheferna finns där ifall någon vill bolla sina idéer med dem. Cheferna försöker att skapa kreativitet bland sina anställda, både på individuella och gemensamma plan inom företagen.

    Chefernas ledarskap stämmer inte överens med alla punkter av min tolkning av det transformativa ledarskapet men de är på god väg att uppfylla dessa. Den tidigare forskningen beskriver inte exakt hur ledarskapet ska utövas utan det är mer riktlinjer.

  • 17277.
    Zimmermann, Angélique
    Dalarna University, School of Education, Health and Social Studies, Social Work.
    Vad innebär hunden för våra brukare?: Personalens erfarenheter av djurassisterade insatser medhundar inom kommunal LSS-dagverksamhet i Dalarnas län.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the present study was to investigate how users are influenced by

    animal-assisted interventions with dogs in municipal day-care centres (developing

    centres or working places for persons with autism and/or intellectual disabilities)

    in Dalarna County. This is a qualitative study, initiated through a quantitative

    mapping concerning the presence of dogs or other animals in all municipal LSS

    day-care centres in Dalarna. Its limited to the staff perspective on the impact of

    dog-assisted interventions on the target group, and results are based on semistructured

    interviews with staff from all municipal day-care centres in Dalarna,

    where users are offered dog-assisted interventions. The results where analysed

    through previous research, KASAM and social responsiveness. They show that the

    dog-assisted interventions promote mental/physical wellbeing and motivate the

    users of the day-care centres to develop physical, mental and social skills. I found

    evidence that users benefit from animal-assisted interventions with dogs – in many

    ways.

  • 17278.
    Zimonjic, Mirela
    et al.
    Dalarna University, School of Education, Health and Social Studies, Caring Science/Nursing.
    Bengtsson, Tina
    Dalarna University, School of Education, Health and Social Studies, Caring Science/Nursing.
    Patienters inställning till insulinbehandling vid typ 2-diabetes – En litteraturöversikt2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background:

    Type 2 diabetes is a disease that has increased at an enormous rate

    over the past years, and is now addressed as a global epidemic. The disease is

    greatly influenced by lifestyle factors, and can therefore, to a large extent, be

    prevented or delayed using the patient

    ’s will power and self-care ability. Health

    enhancing self-care often needs to be completed by tablet treatment. One of the

    nurse

    ’s tasks is to identify the patient’s self-care needs, so that optimal conditions

    for good health can be created. Since type 2 diabetes is a progressive disease,

    many patients may need to make the transition to insulin treatment. This transition

    is perceived differently depending on the individual. Therefore, this study aspires

    to investigate the patients

    ’ experiences of the transition to insulin treatment.

    Aim:

    The aim of this literature review is to compile research based evidence

    regarding attitudes towards insulin, and identify factors to patients with type 2

    diabetes accepting insulin treatment.

    Method:

    A literature review based on 15 articles of qualitative and quantitative

    design.

    Result:

    The majority of the participants in all of the studies had a negative

    attitude towards insulin treatment. This could mainly be seen in patients that had

    not yet started insulin treatment. A strong contributing factor to these negative

    attitudes was a lack of knowledge. Individuals who had received satisfactory

    information about insulin treatment, and had experienced insulin treatment for a

    period of time, showed more positive attitudes.

    Conclusion:

    Insulin treatment is often perceived as something negative, and a

    great deal is due to the lack of knowledge. The key to finding a solution may lie

    in education. By applicating a person-centred approach in the nurse

    ’s work, the

    need for knowledge and education can be adjusted to the individual, so that the

    transition to insulin is more readily accepted by the patient. The subject requires

    more research.

  • 17279.
    Zinderland, Petra
    Dalarna University, School of Education, Health and Social Studies, Educational Work.
    Resonemang i och utanför matematikboken: Taluppfattning kopplat till förmågan att resonera i åk 1–22016Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Matematikboken har funnits och nyttjats i skolan under lång tid. I och med den nya läroplanen från 2011 har förmågan att resonera kommit i fokus, då den anses vara en viktig del av utvecklandet av matematiska kunskaper. Genom att förmågan att resonera hamnat i fokus har betydelsen av matematikböcker där förmågan inkluderas och nyttjas i arbetet med matematik efterfrågats. Syftet med studien är att få kännedom om på vilket sätt eleverna i årskurs 1 och 2 får möjlighet att resonera inom området taluppfattning och användning av tal i arbetet med matematikboken samt i de övriga aktiviteterna inom ämnet matematik. Genom att utföra en kvalitativ studie bestående av läroboksanalys, observationer av lektionstillfällen och intervjuer av verksamma matematiklärare har det resulterat i att resonemang förekommer i två former, imitativt resonemang och kreativt resonemang. Utifrån resultatet som framkommit och i sin tur satts i relation till befintlig kunskap inom området har studien kommit fram till att elever behöver arbeta med både imitativt och kreativt resonemang för att skaffa sig matematiska kunskaper samt vidareutveckla sina förkunskaper inom ämnet matematik. Sammanfattningsvis är min mest grundläggande slutsats att det matematiska lärandet inleds med att eleverna använder sig av det imitativa resonemanget men att de måste lära sig att bemästra det kreativa resonemanget för att vidareutveckla sina kunskaper inom ämnet matematik.

  • 17280.
    Zinderland, Petra
    Dalarna University, School of Education, Health and Social Studies, Educational Work.
    Tal och taluppfattning i matematikläroböcker för de lägre åldrarna2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att få kunskap om hur läroböcker inom ämnet matematik

    är uppbyggda gällande taluppfattning och användandet av tal samt om materialet i de

    aktuella läroböckerna skiljer sig beträffande taluppfattning och talsanvändning i

    årskurs 1-3. Läroböcker utgör en form av läromedel och finns samt används i skolan.

    Taluppfattning är grundläggande för elevernas förståelse och utvecklande av matematiska

    kunskaper och en stor del av matematiken och utgör därför ett intressant ämne att forska

    om. I och med användandet av läroböcker i skolan samt taluppfattningens betydelse

    för utvecklandet av matematiska kunskaper är det intressant att se sambandet mellan

    dessa två.

    För att besvara frågeställningarna har en systematisk litteraturstudie genomförts, det

    vill säga en systematisk inventering av för frågeställningarna relevant tidigare

    genomförd och publicerad forskning. Resultatet av litteraturstudien visar att

    läroböcker berör taluppfattning på olika sätt och arbetar med tal, taluppfattning och

    användning av tal i olika sammanhang. Studierna visar även att läroböckerna

    prioriterar olika områden av taluppfattning medan andra områden fyller en liten eller

    ingen del av lärobokens innehåll. Gestaltandet ser olika ut, men bygger på samma

    innehåll. De berörda studierna som är sammanställda är studier från Cypern, Taiwan,

    Irland, USA, Kina och Grekland. Kina och Taiwan är två av de länderna som

    uppvisar bäst resultat inom ämnet matematik, enligt TIMSS undersökning och i

    denna studie synas två av Kinas läroböcker. En äldre traditionell lärobok som använts

    i många år samtidigt som deras nya reformerade är omarbetad för att förbättra

    elevernas kunskaper ytterligare. Även två läroböcker från Taiwan ingår i denna studie,

    TTA och TTB. Dessa två sticker ut och skiljer sig mycket från de övriga läroböckerna

    från blad annat Cypern och Irland. Både TTA och TTB använder ett unikt utseende

    gällande frågornas utformning och hur de är ställda samt består av tvillingfrågor.

  • 17281.
    Zinderland, Petra
    Dalarna University, School of Education, Health and Social Studies, Educational Work.
    Tal och taluppfattning i matematikläroböcker för de lägre åldrarna2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att få kunskap om hur läroböcker inom ämnet matematik

    är uppbyggda gällande taluppfattning och användandet av tal samt om materialet i de

    aktuella läroböckerna skiljer sig beträffande taluppfattning och talsanvändning i

    årskurs 1-3. Läroböcker utgör en form av läromedel och finns samt används i skolan.

    Taluppfattning är grundläggande för elevernas förståelse och utvecklande av matematiska

    kunskaper och en stor del av matematiken och utgör därför ett intressant ämne att forska

    om. I och med användandet av läroböcker i skolan samt taluppfattningens betydelse

    för utvecklandet av matematiska kunskaper är det intressant att se sambandet mellan

    dessa två.

    För att besvara frågeställningarna har en systematisk litteraturstudie genomförts, det

    vill säga en systematisk inventering av för frågeställningarna relevant tidigare

    genomförd och publicerad forskning. Resultatet av litteraturstudien visar att

    läroböcker berör taluppfattning på olika sätt och arbetar med tal, taluppfattning och

    användning av tal i olika sammanhang. Studierna visar även att läroböckerna

    prioriterar olika områden av taluppfattning medan andra områden fyller en liten eller

    ingen del av lärobokens innehåll. Gestaltandet ser olika ut, men bygger på samma

    innehåll. De berörda studierna som är sammanställda är studier från Cypern, Taiwan,

    Irland, USA, Kina och Grekland. Kina och Taiwan är två av de länderna som

    uppvisar bäst resultat inom ämnet matematik, enligt TIMSS undersökning och i

    denna studie synas två av Kinas läroböcker. En äldre traditionell lärobok som använts

    i många år samtidigt som deras nya reformerade är omarbetad för att förbättra

    elevernas kunskaper ytterligare. Även två läroböcker från Taiwan ingår i denna studie,

    TTA och TTB. Dessa två sticker ut och skiljer sig mycket från de övriga läroböckerna

    från blad annat Cypern och Irland. Både TTA och TTB använder ett unikt utseende

    gällande frågornas utformning och hur de är ställda samt består av tvillingfrågor.

  • 17282.
    Zivkovic, Marko
    et al.
    Stevens Institute of Technology.
    Jääskeläinen, Markku
    Dalarna University, School of Technology and Business Studies, Physics. Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA.
    Search, Christopher P.
    Stevens Institute of Technology.
    Djuric, Ivana
    Stevens Institute of Technology.
    Sagnac rotational phase shifts in a mesoscopic electron interferometer with spin-orbit interactions2008In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 77, no 11, article id 115306Article in journal (Refereed)
    Abstract [en]

    The Sagnac effect is an important phase coherent effect in optical and atom interferometers where rotations of the interferometer with respect to an inertial reference frame result in a shift in the interference pattern proportional to the rotation rate. Here, we analyze the Sagnac effect in a mesoscopic semiconductor electron interferometer. We include in our analysis the Rashba spin-orbit interactions in the ring. Our results indicate that spin-orbit interactions increase the rotation-induced phase shift. We discuss the potential experimental observability of the Sagnac phase shift in such mesoscopic systems.

  • 17283.
    Zou, Luyi
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    An Investigation of the LDA based Topic Model Approachfor Data Mining Twitter Social Network2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent years, Twitter has become a highly popular form of social media.Twitter provides a platform for users to post short messages for followers to read inan on-or off-line fashion. Twitter is used in a variety of ways, from posting aboutpersonal daily life, to keeping up to date with current events.This thesis aims to find a reliable pipeline to analyse and visualize hottest topics(or trends) that people are talking about on Twitter during a period of time. Topicmodel is used to cluster Twitter messages and identify topic words, then topic wordscombined with the tweets’ influences are graphically represented by visualizationsoftware to reflect the trend under the topic. However, two limitations of Twittermessages prevent normal topic model tools from being applied their full potentials:Twitter messages are short and and colloquial. Twitter message provides little usefulinformation for the topic model to work properly. Thus, we proposed an poolingschema to enhance the performance of a topic model on Twitter data. Meanwhile, toidentify a reliable pipeline to do the task, we compared different methodologiesduring the process. We compared performance with and without pooling schema inthe data sampling step, performance with and without TF*IDF in the data processingstep; and finally compare performance of Latent Dirichlet allocation (LDA) withCorrelated Topic Models (CTM) to identify a topic. The results show thatLDA-TF*IDF with pooling schema is the most accurate model to identify Twittertrend.

  • 17284.
    Zouave, Sonia
    Dalarna University, School of Humanities and Media Studies, Japanese.
    Manipulation in Newspaper Articles: A Political Discourse Analysis of Lexical Choice and Manipulation in Japanese Newspaper Crisis Reporting in the case of North Korea2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper analyzes some forms of linguistic manipulation in Japanese in newspapers when reporting on North Korea and its nuclear tests. The focus lies on lexical ambiguity in headlines and journalist’s voices in the body of the articles, that results in manipulation of the minds of the readers. The study is based on a corpus of nine articles from two of Japan’s largest newspapers Yomiuri Online and Asahi Shimbun Digital. The linguistic phenomenon that contribute to create manipulation are divided into Short Term Memory impact or Long Term Memory impact and examples will be discussed under each of the categories.The main results of the study are that headlines in Japanese newspapers do not make use of an ambiguous, double grounded structure. However, the articles are filled with explicit and implied attitudes as well as attributed material from people of a high social status, which suggests that manipulation of the long term memory is a tool used in Japanese media.

  • 17285. Zuczkowski, Andrzej
    et al.
    Colella, Gianluca
    Dalarna University, School of Humanities and Media Studies, Italian.
    Riccioni, Ilaria
    Bongelli, Ramona
    Canestrari, Carla
    Italian come se "as if": evidential and epistemic aspects2014In: Certainty-uncertainty – and the attitudinal space in between / [ed] Cantarini, S, Abraham, W. & Leiss, E, Amsterdam: John Benjamins Publishing Company, 2014, p. 297-393Chapter in book (Refereed)
    Abstract [en]

    The aim of this paper was to analyze the 109 occurrences of Italian come se “as if” in a homogenous written corpus of 780 texts, with the aim to highlight the implied evidential and epistemic aspects, not yet explicitly studied in the pertinent literature. We used an interdisciplinary approach which combines linguistics with aspects of cognitive psychology of communication: (a) a Gestalt Psychology oriented perspective, (b) J.S. Petöfi’s Text Theory, in particular his model of Atomic Text, and (c) our view on evidentiality and epistemicity. From this perspective, we found three types of come se: (1) counterfactual; (2) conjectural (on a literal level); and (3) conjectural (on a non-literal, i.e. symbolic, level).

  • 17286.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Contributions of the Michigan corpora to EAP research and teaching2019Conference paper (Refereed)
  • 17287.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Figurative and Non-figurative language2014In: The 2014 Metaphor Festival: Abstracts, printed version, 2014Conference paper (Refereed)
  • 17288.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    In the world of discourse versus IRL: Reflections on reflexivity in digital communication2019Conference paper (Refereed)
  • 17289.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Invited review of Owtram (2010) “The Pragmatics of Academic Writing”2012In: The European English Messenger, ISSN 0960-4545, Vol. XXI, no 2Article, book review (Other academic)
  • 17290.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Mapping metadiscursive ‘you’ across genres: From research articles to teacher feedback2017Conference paper (Refereed)
    Abstract [en]

    This chapter takes the theme of metadiscourse across genres as a point of departure. To illustrate variation in the use of metadiscourse, reflexive uses of second person ‘you’ are examined in different genres, all of which represent academic discourse. The material includes university lectures, research articles, advanced university student essays and teacher feedback on student writing. The data is analysed both quantitatively, taking frequency into consideration, and qualitatively, taking discourse function into consideration. The extended units in which ‘you’ occurs are compared across genres to highlight the considerable variability of metadiscursive uses. One of the implications of the variation found—which was brought to the fore especially through the study of teacher feedback—is that our conceptualisations of metadiscourse are overly influenced by the type of data that have been in focus in research to date: highly visible written genres at the highly monologic end of the continuum. The metadiscourse in teacher feedback was found to be primarily about solving communication problems rather than organising the discourse and telling the reader how to respond to it. In fact, the feedback material is congruous with Roman Jakobson’s original conceptualisation of the metalinguistic function as solving communication problems.

  • 17291.
    Ädel, Annelie
    Dalarna University, School of Languages and Media Studies, English.
    Metadiscourse2012In: Encyclopedia of Applied Linguistics / [ed] Chapelle, Carol A., Oxford: Wiley-Blackwell, 2012Chapter in book (Refereed)
  • 17292.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Metonymy in the semantic field of verbal communication: A corpus-based analysis of WORD2014In: Journal of Pragmatics, ISSN 0378-2166, E-ISSN 1879-1387, Vol. 67, p. 72-88Article in journal (Refereed)
    Abstract [en]

    Language about language has been studied above all from the perspective of metaphor, neglecting metonymy. This study tests the hypothesis that metonymy is also central within the semantic field of communication. A bottom-up, empirical study of word—one of the most frequent nouns in English—was carried out, based on 4000 tokens from the British National Corpus. word was found to be highly figurative, with metonymic uses (55%) being considerably more frequent than metaphorical uses (24%), but with some overlap, and with the two forms of the lemma displaying different profiles. Although largely an abstract noun,word is even richer in figurative meaning than previously studied body part nouns. The core meaning of wordrefers to the grammatical word, but it is frequently extended through metonymy—and especially synecdoche—to stand for units of communication of varying scope; these are mapped out in the study. The metonymic meanings were found to be more conventionalized in nature than the basic meanings. Metonymy is shown to be a robust phenomenon that, at least in the semantic field of verbal communication, may be more significant than the vastly more-studied phenomenon of metaphor.

  • 17293.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    "Not one word of it made any sense": Hyperbolic Synecdoche in the British National Corpus2016In: Nordic Journal of English Studies, ISSN 1654-6970, E-ISSN 1654-6970, Vol. 15, no 4, p. 1-23Article in journal (Refereed)
    Abstract [en]

    A distinct metonymic pattern was discovered in the course of conducting a corpus-based study of figurative uses of WORD. The pattern involved examples such as Not one word of it made any sense and I agree with every word. It was labelled ‘hyperbolic synecdoche’, defined as a case in which a lexeme which typically refers to part of an entity (a) is used to stand for the whole entity and (b) is described with reference to the end point on a scale. Specifically, the speaker/writer selects the perspective of a lower-level unit (such as word for ‘utterance’), which is quantified as NOTHING or ALL, thus forming a subset of ‘extreme case formulations’. Hyperbolic synecdoche was found to exhibit a restricted range of lexicogrammatical patterns involving word, with the negated NOTHING patterns being considerably more common than the ALL patterns. The phenomenon was shown to be common in metonymic uses in general, constituting one-fifth of all cases of metonymy in word. The examples of hyperbolic synecdoche were found not to be covered by the oftquoted ‘abbreviation’ rationale for metonymy; instead, they represent a more roundabout way of expression. It is shown that other cases of hyperbolic synecdoche exist outside of word and the domain of communication (such as ‘time’ and ‘money’).

  • 17294.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Pragmatics of discourse2016In: Discourse Studies, ISSN 1461-4456, E-ISSN 1461-7080, Vol. 18, no 2, p. 223-226Article, book review (Other academic)
  • 17295.
    Ädel, Annelie
    Dalarna University, School of Languages and Media Studies, English.
    Qualitative analysis of overuse, underuse and equal use in learner corpus research: Learner writing and the textual distribution and rhetorical moves of a linguistic pattern [invited talk]2013Other (Other academic)
  • 17296.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Remember that your reader cannot read your mind: Problem/solution-oriented metadiscourse in teacher feedback on student writing2017In: English for specific purposes (New York, N.Y.), ISSN 0889-4906, E-ISSN 1873-1937, Vol. 45, p. 54-68Article in journal (Refereed)
    Abstract [en]

    Feedback on student writing is a common type of discourse to which university teachers dedicate much time. A pilot corpus of feedback—40,000 words representing five teachers’ comments on 375 student texts—was investigated for metadiscourse, defined as reflexive expressions referring to the evolving discourse, the writer-speaker, or the audience. The overarching question concerned how visible the writer, reader and current text were. To help determine how the feedback data may be unique, comparisons were made to previous studies investigating metadiscourse in other types of academic discourse, both written (university student proficient L1 writing and university student L2 writing) and spoken (university lectures). The feedback data had considerably higher proportions of metadiscourse and the overall frequency of metadiscourse was exceptionally high. The student reader (‘you’) was considerably more visible than the teacher writer giving feedback (‘I’). The material involved large quantities of references to the text, e.g. ‘here’ used to indicate trouble spots. Previously studied data have resulted in a view of metadiscourse as prototypically discourse-organising, but the metadiscourse in feedback is instead problem/solution-oriented, serving the metalinguistic function and aiming to solve communication problems. The findings have led to a revision of the model of metadiscourse in which the roles of the writer, audience and text are multidimensional rather than one-dimensional. © 2016 Elsevier Ltd

  • 17297.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Review of Egan, Thomas and Dirdal, Hildegunn (eds). 2017. Cross-linguistic Correspondences: From Lexis to Genre2018In: Nordic Journal of English Studies, ISSN 1654-6970, E-ISSN 1654-6970, Vol. 17, no 2, p. 247-254Article, book review (Refereed)
  • 17298.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Review of Salazar, Danica. Lexical Bundles in Native and Non-native Scientific Writing: Applying a Corpus-Based Study to Language Teaching2016In: International Journal of Learner Corpus Research, ISSN 2215-1478, E-ISSN 2215-1486, Vol. 2, no 1, p. 125-129Article, book review (Other academic)
  • 17299.
    Ädel, Annelie
    Dalarna University, School of Humanities and Media Studies, English.
    Selecting quantitative data for qualitative analysis: a case study connecting a lexicogrammatical pattern to rhetorical moves2014In: Journal of English for Academic Purposes, ISSN 1475-1585, E-ISSN 1878-1497, Vol. 16, p. 68-80Article in journal (Refereed)
    Abstract [en]

    Learner corpus research involves studying large collections of data to achieve a certain degree of representativeness, which means that it is often not doable to examine a full set of data qualitatively. An important issue, then, is how to select a subset for further qualitative analysis. This study illustrates a selection method, taking quantitative results as a starting-point, for a qualitative study of a lexicogrammatical pattern. Three configurations are examined, involving not only statistically significant differences (overuse and under-use), but also similarities (equal use). What is studied is the anticipatory it pattern ("It is however important to interpret these findings with caution") in apprentice writing in linguistics by learners and native speakers of English. The method yielded 463 tokens in 62 learner and 82 native-speaker essays. The research questions were (i) What are the connections between the selected subpatterns of anticipatory it and specific rhetorical moves? and (ii) Are there indications of learner behaviour in the connections between subpatterns and rhetorical moves? Most subpatterns were found to be specialised for a few moves. The two groups mostly used the subpatterns for the same rhetorical work, but the learners used important and clear subpatterns for a greater range of moves. 

  • 17300.
    Ädel, Annelie
    Dalarna University, School of Languages and Media Studies, English.
    The latest word on figurative language: Metonymy trumps metaphor in the domain of communication2012In: SLE 2012. Stockholm University. Book of abstracts, 2012, p. 6-6Conference paper (Refereed)
343344345346347348349 17251 - 17300 of 17765
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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