hig.sePublications
Change search
Refine search result
567891011 351 - 400 of 26559
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • 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.
  • 351.
    Ahmadi, Nader
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Criminology, Social Work.
    Ahmadi, Fereshteh
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Criminology, Social Work.
    Erbil, Pelin
    Oncology Clinique, Humanite Psychiatry, Istanbul, Turkey.
    Cetrez, Önver A.
    Department of Theology, Uppsala University, Stockholm, Sweden.
    Religious meaning-making coping in Turkey: a study among cancer patients2019In: Illness, crisis and loss, ISSN 1054-1373, E-ISSN 1552-6968, Vol. 27, no 3, p. 190-208Article in journal (Refereed)
    Abstract [en]

    The purpose of the present project has been to carry out international studies on meaning-making coping among people who have been affected by cancer in a number of societies and, thereby, to try to understand the influence of culture on use of these coping methods. Five countries—Sweden, South Korea, China, Japan, and Turkey—are included in the project. Qualitative semistructured interviews have been conducted with persons with a cancer diagnosis. The research group in each country has used, as a foundation, the interview questions developed for the Swedish study. These questions were, however, modified to better suite the sociocultural context of each participating country. The results presented here concern only Turkey and are restricted to religious coping methods. The study consists of 25 cancer patients (18 females and 7 males) between 20 and 71 years of age. The results of the study in Turkey indicated that the RCOPE (Religious Coping) methods are highly relevant for the interviewees. A sociological analysis of the study made from a cultural perspective showed clearly the importance of the idea of being tolerant (Sabr) for patients when coping with the psychological problems brought about by cancer. The study made it clear that culture plays an essential role in the choice of coping methods.

  • 352.
    Ahmadi, Nader
    et al.
    University of Gävle, Department of Caring Sciences and Sociology, Ämnesavdelningen för socialt arbete.
    Hessle, Marie
    Mannikoff, Anna
    Asylsökande barn med uppgivenhetssymtom: ett svenskt fenomen åren 2001-20062006Report (Other academic)
  • 353.
    Ahmadi, Nader
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Psychology, Social work.
    Ljungqvist, ArneSvedsäter, GöranUniversity of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    Doping and public health2016Collection (editor) (Other academic)
    Abstract [en]

    Doping – the use of performance-enhancing substances and methods – has long been a high-profile issue in sport but in recent years it has also become an issue in wider society. This important new book examines doping as a public health issue, drawing on a multi-disciplinary set of perspectives to explore the prevalence, significance and consequences of doping in wider society. It introduces the epidemiology of doping, examines the historical context, and explores the social, behavioural, legal, ethical and political aspects of doping. The book also discusses possible interventions for addressing the problem on organisational and societal levels.

  • 354.
    Ahmadi, Nader
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Psychology, Social work.
    Ljungqvist, Arne
    Svedsäter, Göran
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    Introduction: Doping and Public Health2016In: Doping and Public Health / [ed] Nader Ahmadi, Arne Ljungqvist, Göran Svedsäter, Abingdon: Routledge, 2016, 1, , p. 151p. 1-10Chapter in book (Refereed)
    Abstract [en]

    The concept of “doping” is usually associated with sport, particularly elite sport. In fact, doping means the use of substances or methods that are banned in sport by the World Anti-Doping Agency (WADA) because of their potentially performance-enhancing effects. Their use is, therefore, considered to be against the fair play spirit of sport and can also include significant health risks for the user. However, the use of many doping substances is no longer limited to the world of sport. Doping substances such as anabolic androgenic steroids (AAS) are nowadays used also by people who are not competitive athletes but who want to make use of the effects of AAS in making their bodies more muscular, stronger and impressive in conformity with the current masculine body ideal. The use of AAS and similar substances appears to be growing and has been found in a range of countries previously not researched. At least, recent data obtained from customs seizures, court cases and some surveys suggest that the extent of AAS use outside sport has been underestimated, some reasons probably being an underground circulation of such drugs in the gym and fitness culture and the easy availability of them on the internet. One particular concern is the increasing use of nutritional supplements by growing segments of society. A significant percentage of these products have been shown to contain prohibited substances such as steroids that are not listed on the label. This shows that the nutritional supplement industry needs to be more strictly regulated. Until that happens, supplements of dubious value, content and quality will continue to be easily available around the world. What, then, are the possible reasons that active and health-conscious individuals are willing to take the risk to use preparations such as AAS? A review of the research shows that the most important motive behind the use of AAS outside the elite sports environment, i.e., in a fitness context, is to improve physical appearance. Although most users are boys and young and middle-aged men, also women of various ages use doping substances. Different types of slimming pills are popular among women (including hormone preparations), but possibly even more interesting are the new female fitness and appearance ideals that are connected to muscles and strength. The body has become increasingly important for saying something about who we are. The hunt for the perfect appearance creates a situation where denial instead of acceptance of one’s own body influences the individual’s self-image.

  • 355.
    Ahmadi, Nader
    et al.
    University of Gävle, Department of Caring Sciences and Sociology, Ämnesavdelningen för socialt arbete.
    Lönnback, Eva Britt
    Tvärkulturellt socialt arbete: av socialarbetare för socialarbetare2005Collection (editor) (Other academic)
  • 356.
    Ahmadi, Nader
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Psychology, Social work.
    Svedsäter, Göran
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    "The winner takes it all": Individualization and Performance-Enhancing Drugs and Methods in Sport and in Society2016In: Doping and Public Health / [ed] Nader Ahmadi, Arne Ljungqvist, Göran Svedsäter, Abingdon: Routledge, 2016, 1, , p. 151p. 38-48Chapter in book (Refereed)
    Abstract [en]

    A common misconception in today's society is that everything is (or should be) rational and goal-oriented, which we summarized earlier as pragmatic rationalism. We call this pragmatic rationalism a misconception because it misses a historical fact that individuals' actions are and have never been governed entirely by rational motives. Emotional, ethical and existential considerations influence human actions extensively. Solidarity, willingness to share and even self-sacrifice and prioritizing the good of others before one's own are values that have survived many different economic cultures. Even today's extremely individualized society with its focus on reaching success and winning at any price cannot completely suppress these values. There is an inherent contradiction between the crude egoism of modern individualism and its historical development that largely has its origin in the care of humans.

  • 357.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration. KTH.
    Market orientation and public housing companies in the Swedish declining market2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The licentiate thesis consists of three papers with the particular topic in public housing. They discuss how the public housing companies manage the transition to higher economic demands meeting increased customer and market requirements. These studies focus specifically on how the public housing company deal with market challenges associated with the decision to demolish, maintain and/or new construction. Market-oriented perspective can be a tool for the public housing companies to achieve better customer value and enhance economic development. Although the market orientation concept has contributed to valuable improvements in research, the thesis assumes that it is necessary to distinguish between that the public housing companies operate market-oriented to meet customer requirements and their focus on innovation. Paper I develops market/innovation types and then investigates how public housing companies adapt to these types. It was found that economic conditions in the municipality have a major impact on the housing companies, causing them to act innovatively and create superior customer value by innovations. The study confirms that the implementation of market and innovation orientation contributes to competitive advantages in growing markets, while weak economic conditions impair implementation in declining markets. Paper II addresses how public housing companies in declining markets act based on the concept of market intelligence. This study suggested and tested whether there is a positive link between collecting customer information, disseminating it in the organization, and responding to customer needs, and whether this link has an impact on strategic performance. The result shows that weak links exist in the process; the efficiency of intelligence distribution in public housing companies is affected mainly by their responsiveness to customer needs. Paper III also addresses the public housing companies’ market strategies in declining markets. This study, based on a market-strategic perspective, compares how public housing companies act in relation to customer wants compared to the private housing market. The result shows that public housing companies are more engaged in carrying out new construction, renovation, and reconstruction, as well as taking more social responsibility compared to the private sector. In particular, their concern for the customers’ social needs is evident.

  • 358.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Moderating effects on market orientation and strategic performance: A study of public housing companies in Sweden2018Conference paper (Refereed)
  • 359.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Moderating effects on the market orientation and strategic performance relationship in public housing2019In: Baltic Journal of Management, ISSN 1746-5265, E-ISSN 1746-5273, Vol. 14, no 4, p. 559-577Article in journal (Refereed)
    Abstract [en]

    Purpose - The purpose of this study is to examine how external factors moderate public housing companies’ market orientation and strategic performance relationship.

    Design/methodology/approach – The quantitative method was applied to data from a survey sent to 289 public housing companies in Sweden. A hierarchical, multicollinearity diagnostics–moderated regression analysis is used to test the research hypotheses.

    Findings – The results reveal moderating factors. The companies take several initiatives to inform themselves about customers’ needs and distribute the information within the company, but economic conditions, as well as market and technological turbulence in the municipalities, moderate the relationship between market orientation and strategic performance. Economic conditions make it difficult for public housing companies to strategically act based on market needs when making decisions and planning construction strategies (strategic performance).

    Research limitations/implications – This study is limited by focusing on public housing companies, a sector that differs radically from the open market. The study highlights the effects of moderating factors that are important for companies’ strategic performance and long-term construction strategies. From this limited focus, researchers might use the results to compare both similar and different market situations.

    Practical implications – The results of the study are useful for companies facing a similar market situation of external moderating constraints. The result might be used in future research related to the area in focus.

    Originality –This research adds new knowledge to market research by including the impact of economic conditions, which provide insight into how to develop and use market knowledge in real estate and public housing markets.

  • 360.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    The role of competitive strategy and market orientation: the effect of innovation and sustainability - a study of public housing companies2019Conference paper (Refereed)
  • 361.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration. KTH, Bygg- och fastighetsekonomi.
    The role of market orientation in public housing companies: A study of MO’s effect on construction strategies2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The development of public housing companies in Sweden is strongly influenced by legal, economic, and demographic changes. The companies long tradition of taking responsibility for customer welfare in living have recently been criticized for excessive dominance over price setting, which is claimed to give them competitive advantages in the housing market. New legislation in 2011 requires financial return on investment, implying increased competition with radical changes for the companies. Because of the law, they find themselves transitioning from the role of being responsible for living conditions in Sweden to having to work in a businesslike manner with increased competition.The purpose of this dissertation is to analyze how the public housing companies’ deal with market orientation constructs and what their impact is on construction strategy choices. Theoretically, the market orientation concept is seen as a tool for companies to create superior value for the customers and influence strategic performance, which is a relationship tested and analyzed in this dissertation.The research was conducted through data collection stages using qualitative and quantitative methods. In the first stage, a qualitative pilot study was conducted with interviews of 15 managers in 11 public housing companies in central Sweden. In the second stage, two quantitative comparative studies of public and private housing companies in declining markets in central Sweden were conducted, collecting data from 23 (22 survey respondents) public and 37 private housing companies (16 respondents). In the third and final stage, two quantitative studies were conducted, collecting data from all 289 public housing companies (165 respondents) in Sweden.Results of the five studies show, firstly, that economic condition in the municipality have a major impact on the housing companies’ construction strategies, causing them to act innovatively in order to create superior customer value. Secondly, market orientation efforts contribute to competitive advantages in growing markets, while weak economic conditions limit the companies’ construction strategy choices in declining markets. After analyzing the link between market orientation constructs and construction strategy in declining markets, results showed that the public housing companies demonstrate higher responsiveness to customer demands compared to the private sector, but these have no effects on construction strategy. Thirdly, the analysis of moderating (external) and mediating (corporate social responsibility) effects on the market orientation and construction strategy relationship confirms that economic conditions in society influence construction strategy planning and decisions. The results of the mediating effects of CSR indicate that environmental and social issues have a positive influence on the market orientation and construction strategy relationship.

  • 362.
    Ahmadi, Zahra
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies.
    Vi är lika: Kulturella skillnader och professionalism i internationella projekt2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Title: We are equal. A study of cultural differences and professionalism in international projects.

    Level: Thesis for Master Degree in Business Administration.

    Author: Zahra Ahmadi

    Supervisor: Lars Ekstrand

    Date: 2012-05

    The purpose of my study is to analyze and examine it well-educated people can reduce the cultural differences in interaction with other actors around the world. Part of aims study surveys and analyzes to understand how educated people can communicate and facilitate communication in order to achieve the goals and motivation in international collaboration. Problems can arise from cultural differences in connection with that persons face in society and in international collaboration. In this study, I assume theoretical framework that exists in cultural and communication theme and professionalism to find common objectives within educated groups.

    Method: The purpose of this study, I have chosen to use a qualitative approach. I have conducted interviews with people who work internationally within the company Sandvik and with teachers at the University of Gävle who have worked abroad with teaching. In order to depict how well educated people working in international collaborations, I have seen qualitative research method as relevant. When analyzing the material I have been based on the hermeneutic interpretation in order to elucidate and compare respondents' views on professionalization and the importance of understanding and managing cultural differences in an international context.

    Conclusions: The study shows that highly educated people have a major impact on communication with other people. Professionalism in an international collaboration that is characterized by complexity and knowledge, can thus affect both cultural differences andcommunication in itself. Although personal values differ between different national cultures in terms of language and different ways of working individuals try to adapt to each other in international collaboration. In most cases there are cultural differences that contribute to difficulties in co-operation once, but the study shows that highly educated people solve complexity by applying their knowledge of how problems can be handled. This requires that educated people are aware of the culture, way of interpreting meanings in different contexts, have insight on the institutional structures and rules. Professional people can thus both facilitate communication and leadership, which can contribute to a positive attitude to achieve the objectives of collaboration.

    Suggestions for future research: It may be proposed in the future, a comprehensive study of well-trained groups that meet in different countries. Quantitative can be used methods in both the public and private sectors. It is possible to conduct a quantitative study and compare with qualitative studies and draw conclusions.

    Contribution of the thesis: This study helps to get an attractive understanding of how educated people meet in both the public and private sectors in an international project. My theoretical contribution consists of knowledge in two professional international Swedish organizations. I complement and expand knowledge in the fields of culture and professionalism.

    Despite cultural differences, the professionals communicate regardless of the culture and society they come from. The study can be used by different companies to develop and improve the relationship in an international project. In addition, the study shows that educated people encounter respect and have easier communication than non-educated.

    Keywords: Culture, Communication and Professionalism

    Download full text (pdf)
    Zahra Ahmadi
  • 363.
    Ahmadi, Zahra
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Berggren, Björn
    KTH.
    Public housing companies in transition: from governmental tools to profit-making organizations2020Conference paper (Refereed)
  • 364.
    Ahmadi, Zahra
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration. KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Strategies in declining housing markets: a comparison of public and private housing companies2016Conference paper (Other academic)
  • 365.
    Ahmadi, Zahra
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Lind, Hans
    School of Architecture and the Built Environment, KTH, Royal Institute of Technology, Stockholm, Sweden.
    Sustainable strategies in a declining housing market: a comparative study2018In: International Journal of Management Practice, ISSN 1477-9064, E-ISSN 1741-8143, Vol. 11, no 4, p. 400-421Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is first to examine and comparesustainable strategies within public and private housing companies in decliningmarkets in central Sweden. Then, the study evaluates the impact of newlegislation that requires public housing companies to act in a ‘businesslike’way, in the same way as a long-term private company. A quantitative studywas conducted based on a survey sent to 72 housing companies. The resultsshow that public housing companies are more strategy oriented than privatehousing companies. The results can be viewed as an on-going interactionprocess, where a company’s strategies affect its profit. The study aims toincrease the understanding of activities within housing companies in adeclining market that engage the companies in sustainable strategies toimprove their market knowledge and profit.

  • 366.
    Ahmadi, Zahra
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Sundström, Agneta
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    The market intelligence impact on strategic performance in declining markets2017In: International Journal of Applied Business and Economic Research, ISSN 0972-7302, Vol. 15, no 15, p. 457-473Article in journal (Refereed)
    Abstract [en]

    This study examines how companies in declining markets operate in the context of market intelligence, responding to customer needs and applying them tostrategic performance. A quantitative survey was sent to 214 public housing companies. The results indicate that market intelligence creates commitment and is significant. A positive relationship was found between data gathering, dissemination, and responsiveness, which indicates that the companies comprehend market needs but companies have difficult to manage construction strategies that improve strategic performance. There was a low value of strategic performance; a link between market intelligence and the chosen strategy was not confirmed. Companies know what the market wants but base their decision on previous strategic performanceon economic conditions in the municipality instead.

  • 367.
    Ahmadi, Zahra
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Sundström, Agneta
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    The role of market intelligence in declining markets: public housing companies in Sweden2015Conference paper (Refereed)
  • 368.
    Ahmady, Adris
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Mohammed, Maryam
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Marknadsföringsstrategier Inom Dagligvaruhandel Under Hög Inflation: En Kvalitativ Studie2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Title: Marketing strategies in grocery stores during high inflation

    Level: Student thesis, Bachelor Degree in Business Administration

    Authors: Adris Ahmady och Maryam Mohammed

    Supervisor: Peter Ek

    Date: 2023-june

    Aim: The purpose of this study is to investigate marketing strategies for companies in the grocery trade during a high rate of inflation. In order to contribute to an increased understanding of how companies' marketing is affected, a comparison is made between marketing strategies that companies apply under normal economic circumstances and how these have changed or have been affected during an economic crisis, in this case rising inflation.

    Method: A qualitative research method has been applied in this study, with the implementation of four semi-structured interviews with company managers within ICA and Coop. All the respondents are store managers, who are also locally responsible for the respective store's marketing.

    Results and conclusion: The results of the study have shown that companies in the grocery trade have been affected by the prices and a change in customer behaviour has been observed, which has contributed to the fact that the companies have had to take measures not to lose their customers. During normal circumstances, Coop has placed great emphasis on positioning through assortments that are exclusive, and ICA has similarly made great use of ICA's own brand to stand out from the crowd. During rising inflation, the main focus for these companies has been on offering competitive prices, as well as adapting the stores' supply to customer demand. For ICA, online shopping has been a great opportunity to keep their customers, even if not many changes have taken place in online shopping. Offers and campaigns as well as large price reductions have been current for various goods, depending on customer segments and demand. Social media has also been an important communication strategy for all companies that were interviewed. The respondents have mainly represented smaller local companies, which means that the results of this study cannot be generalized for all markets in the retail trade, or for all companies in the grocery trade.

    Contribution of the thesis: The study has contributed to an increased understanding of the impact of economic crises on companies in the grocery trade, but also provided a little insight into how consumer behavior changes during economically tough times, although the latter has not been part of the purpose of the study.

    Future research: Proposals for further research are an examination of marketing strategies at larger companies in the grocery trade, as well as at wholesalers and suppliers.

    Keywords: Marketing Strategy, inflation, grocery stores, marketing mix

    Download full text (pdf)
    fulltext
  • 369.
    Ahmed, Abdulmuminu
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Criminology.
    Exploring the integration experiences of African immigrant women in the Swedish labour market.2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study explores the employment integration experiences of African immigrant women in the Swedish labour market. It discusses the factors which determined the integration of the African immigrant women into the Swedish labour market. The analysis of this study reveals the hindrances and facilitators that helped and challenged the African immigrant women in obtaining and how they integrated into the Swedish labour market. The result shows that self-motivation, public institutions, networking and connections, Language skills, racial discrimination, and time consumption are pertinent factors in the integration process of the African immigrant into the Swedish labour market. The result from this study were analyzed through empowerment framework approach and the application of inductive thematic analysis. A qualitative method was used with a semi-structured interview and an open ended question.

    Download full text (pdf)
    fulltext
  • 370.
    Ahmed, Ali Mohamed
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Rashid, Obaidullah
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Optimering av flervåningsbyggnadsstruktur genom att ersätta bärande väggar med pelare och balkar2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I takt med att den globala befolkningen fortsätter att växa, ökar efterfrågan på nya bostadsbyggnader avsevärt. Samtidigt har behovet av bostäder och byggande vuxit över hela världenunder de senaste decennierna, vilket har lett till en ökad efterfrågan på byggmaterial. Betong ärdet viktigaste byggmaterialet för flervåningsbyggnader pga. sin hållfasthet, men det bidrarbetydligt till utsläppen av växthusgaser. För att minska koldioxidavtrycket och främja hållbarhet är det avgörande att minimera materialanvändning med moderna byggmetoder.Syftet med denna studie är att optimera flervåningsbyggnadsstrukturer genom att ersättabärande väggar med pelare och balkar. Studien använder en referensbyggnad belägen iSandvikens kommun och verktyget StruSoft FEM-Design. Studien genomförs i två steg.I steg 1 utförs modellering, design och analys av referensbyggnaden med bärande väggar(byggnad 1). I steg 2 genomförs en förändring av byggnadsstrukturen genom att ersätta debärande väggarna med pelare och balkar av armerad betong (byggnad 2). Samma procedurersom i steg 1 upprepas för den omkonstruerade strukturen. Resultaten jämförs medreferensbyggnaden med hänsyn till utnyttjandegrad, deformation, spänningar, reaktioner, viktoch stabilitet.Ersättningen av bärande väggar med bärande pelare och balkar av armerad betong har variteffektiv. Båda strukturerna uppfyller de nödvändiga kraven. Baserat på resultaten ärdeformationen 9 mm för byggnad 1 och 7 mm för byggnad 2, vilket indikerar att skillnaden ideformation mellan de två strukturerna inte är signifikant.Byggnad 1 har en maximal utnyttjandegrad på 87%, medan byggnad 2 har en högre maximalutnyttjandegrad på 99%. Detta innebär att byggnad 2 kan utnyttjas i större utsträckning änbyggnad 1. Reaktionskrafterna är 563,6 respektive 476,4 kN i båda byggnaderna, vilketindikerar att reaktionskrafterna i byggnad 2 är 15% lägre än i byggnad 1. Båda strukturerna ärstabila, men det finns en skillnad i byggnadernas totala vikt. Vikterna på byggnaderna är 4169respektive 3 143 ton. Resultatet indikerar att byggnadens totala vikt minskar med ca 25% vidanvändning av betongpelare och betongbalkar.

    Download full text (pdf)
    fulltext
  • 371.
    Ahmed, Aram
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    ElHaj, Mohamad
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration. None.
    Factors Impacting Female Career Success in Leadership ´´ Insights from female leaders on their journey of professional growth and leadership ``2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    AbstractThe underrepresentation of women in leadership roles has become a global issue. There aremany factors, numerous barriers, and obstacles that prevent women to attain leadership positions and career advancements such as unconscious bias, lack of access to networks and mentors, and a lack of work-life balance support, etc.

    The thesis aims to investigate the leadership style and communication that contribute to thecareer success of women in leadership positions, identify the reasons for the low representation of women in leadership roles, and explore ways to promote female leadership.

    The theoretical framework and literature review focus on the various leadership styles, including transformational, transactional, and laissez-faire, effective communication styles whichcan significantly impact one's ability to lead. In addition, the importance of diverse leadershipin the workplace, gender differences in communication approaches, and strategies to empowerwomen to overcome communication barriers.We will provide a comprehensive understanding of the leadership and communication stylesthat influence women's career success in leadership positions and offer recommendations toorganizations on how to foster gender diversity in leadership roles based on real-life experiences from several interviews with women leaders.

    We will provide in-depth interviews withfemale managers showing their sides of the work life and their experiences and issues leadingto leadership and their struggles to gain a higher position at their organizations. With a mixture of different organizations provided and different countries' points of view. We will provide and show the different leadership styles and communications and how this shows different aspects of female managers’ behaviors and communication. We will show how based onthe information we gather how communication and leadership styles play a massive role inthe workplace environment.

    Download full text (pdf)
    fulltext
  • 372.
    Ahmed, Basem
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Investigation of energy retrofits of a multi-family building by using IDA Simulation Software2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy simulation in building sector was an important issue which can eliminate energy use and improve energy efficiency. The building, which is located at Ringvägen 18 in Ljusdal community in Sweden, was chosen to be the main mission of this research and it was one of eleven objects which were involved in EKG project. First step was to create the model and simulate it to reach heating value of 117 MWh which was reached by EKG project. After getting validation value, many renovations were implemented and the heating value was reduced by 58.7% and the heating demand by 55.2%. Improving of energy use through prefabrication gave reduction of heating value of 70.4% and heating demand of 65.8%

    The LCC part was important issue because it gave clear vision and judgment about the economic and investment issue. The acceptability of the investment decision was decided by 198 answers which were responsible to judge if the investments were good or not. There were 22 types of different renovation and every type included 9 cases which depended on interesting rate and energy price factors. The result was 198 answers which were divided to 100 answers as “YES” for good investment and 98 answers as “NO” for good investment.

    Download full text (pdf)
    fulltext med korrigerad TOC
  • 373.
    Ahmed, Dolovan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Fadul, Mohammed Erik Jamal
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Utsläpp från svenska reningsverk till Östersjön: Granskning av Henriksdals reningsverk, Ryaverket, Sjölunda reningsverk, Kungssängsverket och Duvbackens reningsverk2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    From domestic and industrial waste water will have to be cleaned before it can be released into lakes and streams again. This purification takes place through various stages of treatment plants. Wastewater contains many substances that are harmful to the environment as well as human and animal health, so it is important that the purification that is done is done in an efficient and thoughtful manner. The steps that are common in Swedish cleaning plants are mechanical, biological and chemical purification. These purification steps ensure that larger particles do not come out to the open water, convert nitrogen into nitrogen through the activation process, and that by chemical treatment, the emission of phosphorus is reduced. All of these purification steps can be designed differently and vary from purification plants to purification plants. Therefore, the degree of purification and emissions can distinguish between different treatment plants. Because there are many factors involved in the processes at Swedish waste treatment plants, it is important to carry out annual audits to detect problems that can lead to environmental damage.If cleaning does not work, exercise can increase in lakes and seas, which causes people and animals to suffer. Bottom dead and acid deficiency are already a major problem for the Baltic Sea. In order to reduce the negative environmental effects, emissions of nutrients are drastically reduced. This concerns the release of nutrients from all countries around the Baltic Sea.This study focuses on nitrogen and phosphorus purification from 5 wastewater treatment plants, Henriksdal's purification plant (Stockholm), Ryaverket (Gothenburg), Sjölunda purification plant (Malmö), Kungssängsverket (Uppsala) and Duvbacken purification plant (Gävle). Information about its activities has been obtained through interviews and works own reports.The purification plants use different technical solutions, and all treatment plants meet today's requirements for purification. The biggest difference is the degree of nitrogen purification. All wastewater treatment plants have a history of changes in technical solutions to improve treatment. Cleaning wastewater from households and industries costs a lot of money for the treatment plants, so it's always a challenge for the wastewater treatment plants to clean the water in the best possible way without costing too much.It is expected that the cleaning requirements will be tightened and all treatment plants should continue to develop to increase efficiency. Current purification requirements are designed to suit the recipient's sensitivity. If the EU's idea of ​​the same degree of purification across the country is transformed into requirements, Duvbacken will need to significantly improve the nitrogen treatment at the waste water treatment plant.

    Download full text (pdf)
    fulltext
  • 374.
    Ahmed, Hamdi
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work, Criminology and Public Health Sciences.
    Mental health of adult refugees in Sweden: A scoping review2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Studies have indicated that the prevalence of mental health disorders among refugees has increased. The social capital and socioeconomic status of the host country are believed to influence the development and maintenance of mental health. This study aims to generate knowledge about the factors that affect adult refugees’ mental illness in Sweden and inquires as to the activities in the labor market for preventing mental illness among adult refugees in Sweden.

    This study was conducted using a scoping review method. The author analyzed 14 articles, and the results revealed that refugees are more prone to experiencing mental health problems, such as depression and anxiety, than native-born Swedes.

    This study revealed that the social capital and socioeconomic status of the host country may influence the development and maintenance of adult refugees’ mental health.

    Download full text (pdf)
    Hamdi Ahmed - Master thesis in social work 12 of December 2023 (1)
  • 375.
    Ahmed, Husain
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Bajo, Hozan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Improved U-Net architecture for Crack Detection in Sand Moulds2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The detection of cracks in sand moulds has long been a challenge for both safety and maintenance purposes. Traditional image processing techniques have been employed to identify and quantify these defects but have often proven to be inefficient, labour-intensive, and time-consuming. To address this issue, we sought to develop a more effective approach using deep learning techniques, specifically semantic segmentation. We initially examined three different architectures—U-Net, SegNet, and DeepCrack—to evaluate their performance in crack detection. Through testing and comparison, U-Net emerged as the most suitable choice for our project. To further enhance the model's accuracy, we combined U-Net with VGG-19, VGG-16, and ResNet architectures. However, these combinations did not yield the expected improvements in performance. Consequently, we introduced a new layer to the U-Net architecture, which significantly increased its accuracy and F1 score, making it more efficient for crack detection. Throughout the project, we conducted extensive comparisons between models to better understand the effects of various techniques such as batch normalization and dropout. To evaluate and compare the performance of the different models, we employed the loss function, accuracy, Adam optimizer, and F1 score as evaluation metrics. Some tables and figures explain the differences between models by using image comparison and evaluation metrics comparison; to show which model is better than the other. The conducted evaluations revealed that the U-Net architecture, when enhanced with an extra layer, proved superior to other models, demonstrating the highest scores and accuracy. This architecture has shown itself to be the most effective model for crack detection, thereby laying the foundation for a more cost-efficient and trustworthy approach to detecting and monitoring structural deficiencies.

    Download full text (pdf)
    fulltext
  • 376.
    Ahmed, Javed
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Khan, Abdullah Al Mamun
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Influence of National culture on internal communication process. A study on universities in Bangladesh & Sweden.2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Aim: The aim of this study was to investigate how national culture influence internal communication of university.

     

    Methodology: A qualitative approach was chosen to conduct this research. Semi structured interview were taken. Interviews were taken by face to face, skype and phone call. Ethical approach was considered while interpreting the data.

     

    Findings:

    Our study showed that high power distance has negative impact on internal communication. We found that high power distance creates block between supervisors and subordinates to share information. Thus it creates barriers for effective communication flow and hinders organizations development. Our study also found that power distance is available in both countries but the degree of power distance is varied from one to another. In our study we also found that Individualism and collectivism has effect on internal communication. Our study showed that Individualistic or collectivistic decision making process of university effect internal communication of university in both countries. Previous study suggests that high power distance country tends to be a collectivistic country. Though the result is not always true. However, we found that true in our study.

     

    Contribution: The study adopts employee centric approach to explore the effects of culture on internal communication. This is an important contribution to previous researches that focused on internal communication from different perspectives, inclusion of cultural differences on internal communication has added value to the research field. Moreover, this paper contributes insights in cultural differences as well as employee perspective and by doing so it suggests theorist and practitioners that how internal communication can relate to employee’s engagement in different cultural perspectives.

     

    Limitations: The major limitation of this study was that this study only focused on Hofstede’s power distance and individualism as cultural dimensions. Other dimensions were not focused. Another limitation of this study was the sample size. The sample size is too small to represent the whole population in regards to university perspective.

     

    Suggestions for further research: Additional qualitative or quantitative methods can be required to explore the findings in different aspects. The study focuses on the educational institute. The findings may vary in accordance with the different industry and sectors. The study provides the guidelines regarding the impact of cultural differences on internal communication. Future research could consider other important factors that may have profound impact on internal communication in different settings.

     

    Download full text (pdf)
    fulltext
  • 377.
    Ahmed Mohamed Ahmed, Mazz
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Traffic Model Based Energy Efficient Radio Access Network2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As the concerns about global energy consumption increased the matter of energy consumption in Radio Access Networks (RANs) became an important issue especially with the exponential growth in demanded traffic. This interest of developing innovative technologies to reduce the expected energy consumption by the mobile communication sector was driven by environmental concerns and cost reduction.

    The aim of this thesis is to introduce a new methodology to make the Radio Access Network (RAN) more energy efficient based on jointly the demanded throughput and a realistic traffic profile. Furthermore, to find a metric that quantifies the relation between the Energy Efficiency (EE), Spectrum Efficiency (SE) and demanded throughput.

    The proposed methodology for reducing the energy consumption in the RAN characterizes the offered throughput in order to determine the sufficient energy needed. The manner for reducing the energy consumed by the RAN is simply by switching (OFF/ON) Base Stations (BSs) based on the demanded throughput which introduces an energy efficient RAN.

    The results show a significant reduction in the energy consumption with regard to the demanded traffic. Moreover, it gives a measure of the EE with consideration to the SE which enhances the performance evaluation from an EE point of view during the RAN planning phase.

    Download full text (pdf)
    fulltext
  • 378.
    Ahmed, Mohamed
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Maxamed, Maxamed
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Modell för beslutsfattande avseende hållbar logistik: I både tjänsteföretag och tillverkningsföretag2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In any successful business, it is important to establish a dedicated management with the ability to make critical and sustainable decisions. Policy makers are a major and perhaps the biggest factor in a company and usually it is the managers who are also decision-makers. There are a number of aspects to keep in mind in order to make as appropriate decisions as possible, which can be anything from personality traits to how market analytic decision-maker is.

    The purpose of this thesis is to develop a model for decision-making on sustainable logistics, in both manufacturing companies and service companies in Sweden. Literature studies and interviews are conducted in order to answer the purpose. Through the literary study, significant factors can be found, for example crisis management and trust, prejudice and character traits.

    This work’s empirical material is based on interviews in four different organizations regarding their decision making and their approach to sustainable logistics. These organizations are both service and manufacturing companies, which gives the work a breadth and generalizability.

    The identified factors that are developed through the case studies include emotionality and rationality, trust, and transparency. Several factors in the literature are clearly consistent with the significant factors in the study result. The factors that both the service and manufacturing companies have in mind when making decisions regarding sustainable logistics are presented in the results. The conclusion of this study is a model that visualizes the factors one should keep in mind when making decisions regarding sustainable logistics. These factors are trust, supplier selection, unity, facts, transparency and empathy. Based on these factors, any company with a dedication and commitment to long-term decision-making processes can make wise and effective assessments.

    Download full text (pdf)
    Modell för beslutsfattande avseende hållbar logistik
  • 379.
    Ahmed, Motasim
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences. Radarbolaget AB.
    Single-Layer Metamaterial Absorber for Radar Application2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the radar systems, the crosstalk or antenna-to-antenna interference between the radar antennas is useful in some cases. However in some application the received signal is too weak such as wall crack detection and it might affect the accuracy of the radar system. The aim of this thesis is to design, fabricate and test a single layer metamaterial absorber operates from 1 GHz to 4 GHz. The metamaterial absorber can be used as a barrier between the antennas or even in the antenna housing in order to reduce or prevent the antenna-to-antenna interference.

    The method used to fulfill the goal is to shift the frequency response of a known structure by changing the dimension to the wanted band. The software HFSS used to design and simulate the proposed structure which made of L-shaped copper placed diagonally over a substrate separating it from a continuous copper plane. The simulation results exhibit a wideband absorption response of 2.42 GHz ranging from 1.9 GHz to 4.32 GHz. The structure has been simulated over the dimension variation to investigate the flexibility and sensitivity of the designed single layer structure.

    The fabricated metamaterial absorber measured over the direct incident waves. The structure reveals a wideband absorption response of 1.69 GHz ranging from 2.23 GHz up to 3.92 GHz with more than 90% absorptivity. The structure also exposed that the response of the structure starts to create two bands within the wanted band by increasing the angle of the incident waves. 10° polarization angle gives more than 80% absorptivity response. 

    Download full text (pdf)
    fulltext
  • 380.
    Ahmed, Omar
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology.
    Sambandet mellan muskuloskeletala besvär och synergonomi bland yrkeschaufförer: En tvärsnittsstudie2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Problemformulering: Muskuloskeletala besvär är vanligt bland yrkeschaufförer i den svenska transportsektorn, och synergonomi är en ofta underskattad riskfaktor. Begränsad forskning om sambandet mellan samsynsproblem och muskuloskeletala besvär gör att problemets omfattning och konsekvenser är oklara. Samsynsproblem är svårigheter att använda båda ögonen samtidigt för att se och bearbeta bilder.

    Syfte: Syftet med den här tvärsnittsstudien var att undersöka förekomsten av samsynsproblem och muskuloskeletala besvär bland yrkeschaufförer och om muskuloskeletala besvär samvarierar med samsynsproblem.

    Metod: Data i studien hämtades från ett register. Det var totalt 197 yrkeschaufförer som besvarade enkäten. Förekomsten av samsynsproblem och muskuloskeletala besvär analyserades genom deskriptiv statistik och studiens andra frågeställning har analyserats genom inferentiell statistik och inkluderade två regressionsanalyser.

    Resultat: Förekomsten av samsynsproblem totalt i populationen var 18% och förekomsten av muskuloskeletala besvär totalt i populationen var 22%; taxi- och busschaufförer var överrepresenterade. Regressionsanalyserna visade att muskuloskeletala besvär och samsynsproblem samvarierar (p < 0.05) med och utan kontrollvariabler. I den justerade regressionsanalysen samvarierar variabeln socialt stöd i hemmet med muskuloskeletala besvär hos taxichaufförer och socialt stöd i arbetet hos långtradarchaufförer.

    Slutsats: Yrkeschaufförer är sannolikt en yrkeskategori som har en hel del ohälsa och ett stressfullt jobb. Studien visar en association mellan muskuloskeletala besvär och samsynsproblem bland yrkeschaufförer, men den fastställer ingen kausalitet. Det finns begränsad forskning om denna yrkeskategori, och mer forskning behövs.

    Download full text (pdf)
    fulltext
  • 381.
    Ahmed, Rijon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Evaluation, Design & Development of a Prototype 3-Link Mini Robot Manipulator2022Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    A 3-link robotic arm was designed, constructed, and tested as part of the thesis work. This prototype will assist students in applying their robotics and control system theory knowledge to real results. The kinematic equations are created to help with trajectory planning. Evaluation of different parameters was determined like (angles at which the servo motor operated, link length at which the servo can carry, spatial velocity, DH parameter, and Homogeneous transformation matrix). An Arduino-based closed-loop control system is built. Four Servo motors were used which are being controlled by Arduino UNO and Leonardo. The Arduino IDE is used to write proper codes. The main aim of the study was to apply the knowledge of robotics and control systems to develop a functional mini robot from scratch. Specifically, the thesis presents how to build a robotic arm that can move and lift objects. And, this task is done by using different controlling techniques where potentiometer, Bluetooth Module, and IR senor were used and compared which technique gives better results. The structural components had several issues. The project's linkages foundation and gripper are all 3-D printed pieces that are being designed using Autodesk Inventor Professional 2021 software. Although they did not cause any problems with strength, there were some difficulties with properly tightening the gears onto the shaft. To overcome these difficulties glue is being used so that all servo motors hold with the link properly. In a broad sense, the robot can position and orient the end-effector to pick and place the object accurately from a distance.

    Download full text (pdf)
    fulltext
  • 382.
    Ahmed, Sharif
    et al.
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Islam, Md.Tawhidul
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Business administration.
    Factors for Reshoring Decision: A Supply Chain Perspective2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: The study aims to explore the supply chain factors that impacts reshoring decisions.Methods: The study followed a qualitative research method based on exploratory research. In order to attain the context of situation-based interpretation, semi-structured interviews were conducted based on two Swedish firms engaged in reshoring initiatives. The collected data were individually analysed followed by a cross-case analyses.Findings: The research findings identified several experiences within the supply chain factors that have an influence over the reshoring decision. Firstly, firms are required to secure the replacement of offshored suppliers in their home country and ensure the access to the abundance of raw materials while reshoring. Secondly, realignments are needed for components to suit with organizational values, integrate to obtain independence from external entities and utilize pre-existing assets to mitigate challenges. Thirdly, increase in customer participation for firm’s product decision and locally produced goods can further enhance brand perception. Lastly, proximity allowed firms to streamline logistical communication, deter investment cost and promote R&D capabilities.Contribution: The study contributes in the knowledge of reshoring through the lens of supply chain management and also provides managerial context for reshoring decisions. The sole focus on supply chain factors enhances the theoretical expansion of reshoring and allowing further study materials into the emerging research field of reshoring. In addition, the research findings from four different supply chain factors allows a multifaceted contribution for organizational managers. Managers can individually or conjointly utilize the ideas on resource, reconfiguration, customer and proximity for reshoring decisions.Conclusions: The results from the study and the fulfilment of the aim shows that reshoring is a case of strategic decision making by firms who aim to secure a better competitive standpoint by repatriating production back to the home country.

    Download full text (pdf)
    fulltext
  • 383.
    Ahmed, Sipan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Java integrering med PLC2020Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    Digitization has been given a greater role in the monitoring and control of a processing plant. This trend will grow globally to achieve a smarter production chain that generates ecenomic profits.

    The purpose of this thesis was to develop an existing process that respresents an automated drilling station. THis i scontrolled by integrating Java-netbeans software into the PLC hardware with a user interface that can read the data flow of PLC.The drilling station is controlled by PLC.

    This work describes the possible methods for achieving integration between Java-netbeans and PLC.

     The essential part of the work was literature study, programming of source code and programming of PLC. This work achieved all the objectives.

    Download full text (pdf)
    fulltext
  • 384.
    Ahmed Waqas, Hafiz
    et al.
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Bahrami, Alireza
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Sahil, Mehran
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Poshad Khan, Adil
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Ejaz, Ali
    National University of Science and Technology, Risalpur 23200, Pakistan.
    Shafique, Taimoor
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Tariq, Zain
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Ahmad, Sajeel
    Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Swabi 23640, Pakistan.
    Onuralp Özkılıç, Yasin
    Necmettin Erbakan University, Konya, Turkey.
    Performance Prediction of Hybrid Bamboo-Reinforced Concrete Beams Using Gene Expression Programming for Sustainable Construction2023In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 16, no 20, article id 6788Article in journal (Refereed)
    Abstract [en]

    The building and construction industry’s demand for steel reinforcement bars has increased with the rapid growth and development in the world. However, steel production contributes to harmful waste and emissions that cause environmental pollution and climate change-related problems. In light of sustainable construction practices, bamboo, a readily accessible and ecofriendly building material, is suggested as a viable replacement for steel rebars. Its cost-effectiveness, environmental sustainability, and considerable tensile strength make it a promising option. In this research, hybrid beams underwent analysis through the use of thoroughly validated finite element models (FEMs), wherein the replacement of steel rebars with bamboo was explored as an alternative reinforcement material. The standard-size beams were subjected to three-point loading using FEMs to study parameters such as the load–deflection response, energy absorption, maximum capacity, and failure patterns. Then, gene expression programming was integrated to aid in developing a more straightforward equation for predicting the flexural strength of bamboo-reinforced concrete beams. The results of this study support the conclusion that the replacement of a portion of flexural steel with bamboo in reinforced concrete beams does not have a detrimental impact on the overall load-bearing capacity and energy absorption of the structure. Furthermore, it may offer a cost-effective and feasible alternative. 

    Download full text (pdf)
    fulltext
  • 385.
    Ahmic, Rijad
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology.
    Andersson, Marcus
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology.
    Generationella skillnader inom arbetsmotivation2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to determine whether there was a difference in workmotivation between two generations (generation X + millennials) through examininghow the generations estimated their basic needs of satisfaction and whether there was asignificant difference in how the generations estimated their intrinsic and extrinsicmotivation in the workplace. The study was of a quantitative approach and wasconducted through a survey in which 53 participants participated. The instruments usedin the study were Basic Psychological Need Satisfaction Scale - Work Domain(BPNSFS) and Work Extrinsic and Intrinsic Motivation Scale (WEIMS). BPNSFSmeasured the participants basic needs at work and WEIMS their inner and outermotivation as is based on the Self-Determination Theory. The results showed nosignificant difference in how the generations estimated their basic psychological needsat work. However there was a significant difference between the generations where themillennials rated their intrinsic motivation in the workplace higher than generation X,no significant difference was found in how the two generations rated their outermotivation.

    Download full text (pdf)
    fulltext
  • 386.
    Ahnberg Åsenius, Elisabeth
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Lekmöjligheter och trafiksäkerhet för barn i stadsmiljöer: Fallstudie av centrala Falun2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Small children in the age around two to ten needs space to play and move around to be able to develop, and these needs should be considered in the spatial planning practice. Unfortunely there are signs that childrens need for places to play and move around have lost in priority in spatial planning practice in Sweden the last decades. For example research shows that childrens access to public places to play at in swedish citys is reduced. Also childrens possibilities to move around freely in swedish cities are continuously reduced due to increasing traffic. It has also been noted that fewer children walk or bicycle on there own to school and bicycling in the spare time has also been declining.   

    The aim of this study has been to exmine childrens possibilities to play and move around independently in urban environment. The study is restricted to a casestudy of the city-environment Falun-Centrum. That is an area of ca 2,5 km2 predefined by Falu kommun. It contains the city-center with shops, parks, roads, residential areas, kindergardens, schools etc. Information has been collected by a postal survey sent to guardians of 100 children (about 20 % of the total number in the area) that were older than one year and younger than eleven years during 2017 living in the casestudy-area.

    The results are based on 53 answers; 39 answers to the postal survey and 14 answers to additional interwievs over telephone. The answers show that in Falun-Centrum the respondents experience that their children have quite good access to places to play at in their vicinity. Field inventory of the places showed that many of the places were spacious enough to allow vast playing and had green and varied terrain, which is good. Though, the results about the safety aspects in traffic shows that there are a lot of traffic hazards that prevent the children to move around independently in the area.

    In summary it means that the children in general have good places to play at in there vicinity (although there are exeptions), but that they can not go there on their own due to traffic hazards. The lack of traffic safety also means that the conditions for them to go to, explore and get to know new places in their surroundings are severely limited. In the long run it limits the development of their geographichal imagination of their urban surroundings. It also limits their opporunities to meet, get to know and understand other persons in the city. In the long run it inhibits the urban social sustainability.

    Download full text (pdf)
    fulltext
  • 387.
    Ahne, Ingemar
    et al.
    University of Gävle, Department of Education and Psychology, Ämnesavdelningen för didaktik.
    Söderhäll, Bengt
    University of Gävle, Department of Education and Psychology, Ämnesavdelningen för didaktik.
    HiG har ännu inte nått fram2002In: Gefle Dagblad, ISSN 1103-9302, Vol. 28 oktoberArticle, book review (Other (popular science, discussion, etc.))
    Abstract [sv]

    HÖGSKOLEDEBATT

    Tisdagen den 21 oktober hade Gefle Dagblad förstasidesrubriken: "Lärarutbildningen som ett dagis" Vi tycker det är en mycket olycklig formulering. Rubriken och artikeln andas fördomar mot förskolan

  • 388.
    Ahnfeldt, Tomas
    University of Gävle, Department of Technology and Built Environment.
    Geometry for CAD Toolbox2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 389.
    Aho, Emmy
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences.
    Johansson, Sofia
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences.
    Personliga assistenters upplevelse av deras psykologiska kontrakt2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The purpose of the study was to examine how personal assistants experience their psychological contract and how the psychological contract was fulfilled against their supervisor or manager.A qualitative method was used and seven interviews were conducted with personal care assistants from various workplaces. The interviews were analysed with thematic analysis and resulted in five main themes. Expectations, personal but not private, what really stands in the contract, how people look at the profession and fulfilment. In conclusion, the main result was that the personal care assistants experienced that the internal psychological contract consisted of the relation to the supervisor or manager and the accessibility to the employer. The personal care assistants felt that the contents of the external psychological contract consisted of the work duties, employment security, working hours and the attractiveness of the profession. The majority of the respondents felt that the internal and external psychological contract was fulfilled. None of the respondents considered that the internal and external psychological contract was not fulfilled at all.  

    Download full text (pdf)
    fulltext
  • 390. Ahola, Marja
    et al.
    Haikala, Raisa
    Zafar, Afnan
    Opiskelemaan pääsy ja työllistyminen haastavat ulkomaiset korkeakouluopiskelijat – muut maat keräävät osaajat2019In: LAMK Pro, ISSN 2489-3765, no 15-novArticle in journal (Other academic)
  • 391. Ahola, Marja
    et al.
    Zafar, Afnan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Industrial Management. University of Gävle, Center for Logistics and Innovative Production.
    Relationship Between Frugal and Inclusive Innovation and Digital Employment Solutions (DES): A Review2021In: Human Interaction, Emerging Technologies and Future Applications III / [ed] Ahram T., Taiar R., Langlois K., Choplin A. (eds), Switzerland: Springer, Cham , 2021, 3, p. 398-403Chapter in book (Refereed)
    Abstract [en]

    Inclusive and frugal innovations are the key to managing workforce potential of the underdeveloped regions of South Asia (SA). Digital employment solutions (DES) can help to improve the targeted mobility of labour between developed and underdeveloped regions and countries. This research explores the relationship between frugal and inclusive innovations and DES. This review study analyses 16 articles to investigate this relationship. The study found direct and indirect relationships among frugal and inclusive innovations, DES and the employment situation in developed and underdeveloped regions and countries. Frugal innovations and DES may be an appropriate solution to tackle the employment problems in SA but cultural, social and economic barriers can affect the success of the overall process. Researchers and policymakers should, however, carefully evaluate the nature of target regions, the degree of cooperation and evaluation of various related barriers.

  • 392.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Andersson, Hanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Bökman, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    How do people aggregate value? An experiment with relative importance of criteria and relative goodness of alternatives as inputs2022In: Journal of Multi-Criteria Decision Analysis, ISSN 1057-9214, E-ISSN 1099-1360, Vol. 29, no 3-4, p. 259-273Article in journal (Refereed)
    Abstract [en]

    The concept of importance of criteria is used as a central element in several decision making contexts, specifically in value aggregation, e.g. as an input to decision support tools. For example, in the analytic hierarchy process (AHP) decision makers are asked to estimate how much more important one criterion is than another. However, it is not clear how people understand aggregation models based on importance of criteria in decision making situations. The purpose of this descriptive study is to investigate if people find an aggregation model in simple value aggregation tasks which remind of the way AHP elicits the input. Further, the purpose is to investigate if people's tendency to find a model depends on their cognitive abilities. In an exploratory laboratory experiment, participants assessed which of two alternatives is the best, based on information about the importance of two criteria and how good the two alternatives are compared to each other with respect to these criteria. The results confirm that people are willing to use importance of criteria and goodness of alternatives as input in value aggregations and show three main models for aggregation. More participants with higher numeracy applied a clear model compared to those with lower numeracy. None of the identified models was one of AHP's models but one of them reminded of one of the ways input can be aggregated in the AHP. The three models identified in the experiment are based on lexicographic order, multiplication and a combination of multiplication and addition. How the results could be used in a prescriptive context is discussed in the paper.

    Download full text (pdf)
    fulltext
  • 393.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Elmqvist, Åsa Katarina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Hjelmblom, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Multi-criteria reasoning models for value aggregation in wind power permit application assessment2023In: Renewable Energy Focus, ISSN 1755-0084, Vol. 45, p. 210-219Article in journal (Refereed)
    Abstract [en]

    Assessment of an application for wind power establishment is a multi-criteria problem including the coreproblem: whether to grant permission or not. In Sweden, County Administrative Boards decide the outcomes of these kinds of applications. Five permit officers were interviewed to investigate the difficultiesand the type of value aggregation in this work, and to test reasoning models as possible decision supporttools. The commonly used type of aggregation was condition-based aggregation. Aggregation based onvalue differences, which means weighing together aspects for and against the wind power establishment,was considered difficult to apply by the respondents. Most of them agreed that some of the aspects thatspeak against granting permission could be aggregated but that aggregation of all aspects would be harddue to differences between aspects. In addition, the value of the main aspect that speaks for permission,climate friendly energy supply, is very difficult to estimate. Thus, aggregation based on value differencesis a difficult question and how it could be performed is discussed in the paper. If policymakers wish tomake it possible to take both positive and negative aspects into consideration and to discuss thetrade-offs transparently, the investigated method can be a way forward.

    Download full text (pdf)
    fulltext
  • 394.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Finlay, R.
    Effects of elevated nickel and cadmium concentrations on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris seedlings2001In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 236, p. 129-138Article in journal (Refereed)
    Abstract [en]

    The effects of Ni and Cd on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were investigated in a pot experiment. Seedlings were either inoculated with Laccaria bicolor (Maire) Orton or left uninoculated before being planted in pots containing a mixture of sandy soil from the B-horizon of a coniferous forest, small stones and pure quartz sand. The pots were supplied with small amounts of a balanced nutrient solution every 24 h using peristaltic pumps. Nickel or Cd were added as chlorides to the nutrient solution at levels of 85 μM Ni (Ni 1), 170 μM Ni (Ni 2), or 8.9 μM Cd. Mycorrhizal colonisation of the roots was nearly 100% in the mycorrhizal treatments. The mycorrhizal seedlings grew significantly better than the non-mycorrhizal ones. The weight of mycorrhizal seedlings in the Ni 2 treatment was 29% lower than that of the mycorrhizal controls, but still 34% greater than that of the non-mycorrhizal seedlings not exposed to metals. There was an overall, statistically significant, negative effect of metals on plant yield. Mycorrhizal plants had lower root:shoot (R:S) ratios than non-mycorrhizal plants and the R:S ratio was increased by metal exposure, particularly in the non-mycorrhizal seedlings. Plant concentrations of Cd or Ni were not affected by mycorrhizal colonisation, but total uptake of Cd and Ni was higher in bigger mycorrhizal seedlings. Nickel decreased P concentration in all seedlings and Cd decreased P concentration in the non-mycorrhizal seedlings. Generally, the mycorrhizal seedlings grew better than non-mycorrhizal ones and had better P, K, Mg and S status. Root growth was not significantly affected by the metal treatments. The reduction in mean shoot growth of non-mycorrhizal plants, relative to the metal-free control, appeared higher than in mycorrhizal plants but was not statistically significant due to high variation in the non-mycorrhizal plants not exposed to metals. The main mycorrhizal effect was thus increased nutrient uptake and growth of the seedlings.

  • 395.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Göransson, A
    Finlay, R
    Growth and nutrient uptake of ectomycorrhizal Pinus sylvestris seedlings treated with elevated Al concentrations and decreased levels of base cations2003In: Tree Physiology, ISSN 0829-318X, E-ISSN 1758-4469, Vol. 23, no 3, p. 157-167Article in journal (Refereed)
    Abstract [en]

    Models of the effects of elevated concentrations of aluminum (Al) on growth and nutrient uptake of forest trees frequently ignore the effects of mycorrhizal fungi. In this study, we present novel data indicating that ectomycorrhizal mycelia may prevent leaching of base cations and Al. Mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were grown in sand obtained from the B-horizon of a local forest. In Experiment 1, non-mycorrhizal seedlings and seedlings inoculated with Hebeloma cf. longicaudum (Pers.: Fr.) Kumm. ss. Lange or Laccaria bicolor (Maire) Orton were provided with nutrient solution containing 2.5 mM Al. Aluminum did not affect growth of non-mycorrhizal seedlings or seedlings inoculated with L. bicolor. Seedlings colonized by H. cf. longicaudum had the highest biomass production of all seedlings grown without added Al, but the fungus did not tolerate Al. Shoots of seedlings colonized by L. bicolor had the lowest nitrogen (N) concentrations but the highest phosphorus (P) concentrations of all seedlings. The treatments had small but significant effects on shoot and root Al concentrations. In Experiment 2, inoculation with L. bicolor was factorially combined with the addition of a complete nutrient solution, or a solution lacking the base cations K, Ca and Mg, and solutions containing 0 or 0.74 mM Al. Seedling growth decreased in response to 0.74 mM Al, but the effect was significant only for non-mycorrhizal seedlings. Mycorrhizal seedlings generally had higher P concentrations than non-mycorrhizal seedlings. Aluminum reduced P uptake in non-mycorrhizal plants but had no effect on P uptake in mycorrhizal plants. Mycorrhizal colonization increased the pH of the soil solution by about 0.5 units and addition of Al decreased the pH by the same amount. We conclude that the presence of ectomycorrhizal mycelia decreased leaching of base cations and Al from the soil.

  • 396.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Odelstad, Jan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Evaluation of simulations with conflicting goals with application to cleaning of young forest stands2006In: Proceedings of ISC 2006 (Forth International Industrial Simulation Conference), 2006, p. 498-503Conference paper (Other academic)
  • 397.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Odelstad, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Simulation as a tool for the evaluation of forest management treatments2010In: ESM'2010 - The 2010 European Simulation and Modelling Conference / [ed] Gerrit K. Janssens, Katrien Ramaekers and An Caris, Ghent: EUROSIS-ETI , 2010, p. 426-433Conference paper (Refereed)
    Abstract [en]

    Cleaning of young forest stands is a multicriteria problem with conflicting goals. This kind of forest management treatment is performed by human beings but it is possible that this work may be performed by artificial agents in the future. The artificial agents need detailed information about how to clean a forest stand and/or what are the goals for cleaning. One problem in development of cleaning rules for artificial cleaning agents is that explicit knowledge about good cleaning results is not detailed. In this paper we present a tool for developing and testing rules and judging evaluation functions for cleaning. We illustrate this tool by presenting examples of some ways to clean forest stands in a computer environment and we present how the cleaning results can be evaluated. In order to obtain material for experiments it is also possible to simulate forest stands using this tool.

  • 398.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Odelstad, Jan
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Simulation of cleaning of young forest stands2005Report (Other academic)
  • 399.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Roitto, M
    Markkola, A M
    Ranta, H
    Neuvonen, S
    Effects of nickel and copper on growth and mycorrhiza of Scots pine seedlings inoculated with Gremmeniella abietina2004In: Forest Pathology, ISSN 1437-4781, E-ISSN 1439-0329, Vol. 34, no 6, p. 337-348Article in journal (Refereed)
    Abstract [en]

    Scots pine (Pinus sylvestris) seedlings were planted in soil originating from two localities with different background levels of nickel and copper. In addition, some of the seedlings were exposed to additional nickel (20.5 mg Ni/l of soil) or copper (63.5 mg Cu/l of soil), or a combination of both Ni and Cu, via soil without direct shoot exposure during their second growing period. The seedlings were either irrigated with spring water (pH 6) or got only natural rain during the whole field experiment. All seedlings were inoculated with conidia of a shoot-pathogen Gremmeniella abietina during their third growing season, and harvested the following spring. Lengths of shoots of different year-classes were used as growth estimates. In roots, the proportion of fungal (assumedly mycorrhizal) biomass was estimated by measuring ergosterol concentration. Guajacol peroxidase activity was measured. Short roots were classified into two groups according to their condition and the composition of the mycorrhizal community was expressed as a proportion of morphotypes in the roots. The seedlings exposed to additional Ni had higher shoot growth than the seedlings in the other treatments. The mean Ni concentration in the roots of seedlings exposed to additional Ni was 79 p.p.m. and in other seedlings 16 p.p.m. Additional Ni also decreased the frequency of clearly senescent short roots and the proportion of the mycorrhizal morphotype with the thinnest mantle. These results indicate that the Ni exposure levels used in this experiment had some positive effects on the seedlings. The relative fungal biomass was about 6% lower (p = 0.0981) in the fine roots of seedlings treated with additional Cu. The mean Cu concentration in the roots of seedlings exposed to additional Cu was 256 p.p.m. and in other seedlings 29 p.p.m. Peroxidase activity, which was used as a general stress indicator in this study, was not affected by any of the treatments. The shoot growth and the relative biomass of fungi in the fine roots were positively correlated in all seedlings, and this correlation was stronger in seedlings exposed to additional Ni that were not irrigated compared with seedlings not exposed to additional Ni that were irrigated. The frequency of asymptomatic infections of G. abietina was positively correlated with the proportion of senescent short roots in the irrigated seedlings but not in not-irrigated seedlings. The general condition of seedlings may be an important factor for infection by G. abietina when moisture is high enough for the fungi to infect seedlings by conidia.

  • 400.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Van Hees, P. A. W.
    Lundström, U. S.
    Finlay, R. D.
    Organic acids produced by mycorrhizal Pinus sylvestris exposed to elevated aluminium and heavy metal concentrations2000In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 146, no 3, p. 557-567Article in journal (Refereed)
    Abstract [en]

    A cultivation method was developed to enable exposure of ectomycorrhizal plants with intact extramatrical mycelium to solutions containing different concentrations of aluminium or heavy metals. Pinus sylvestris seedlings colonized by Suillus variegatus (two isolates), Rhizopogon roseolus or Paxillus involutus (two isolates) were used. Seedlings were transferred to Petri dishes containing glass beads and exposed to elevated concentrations of Al, Cd, Cu, or Ni in two ways: immediately following transfer; and after allowing mycorrhizal seedlings to develop an extraradical mycelium that colonized the interface between the upper surface of the beads and the metal-containing solution. Production of organic acids in mycorrhizal and non-mycorrhizal systems was measured by withdrawing samples from the solution and analyzing by HPLC. In most experiments, levels of oxalic acid were significantly higher in mycorrhizal treatments than in non-mycorrhizal controls. The measured levels of organic acids were variable, but the results obtained suggest that production of oxalic acid is stimulated by exposure to elevated Al in mycorrhizal seedlings colonized by S. variegatus and R. roseolus. Elevated Al concentrations also increased oxalic acid production by non-mycorrhizal seedlings significantly in two of four Al experiments performed, but the measured concentrations were significantly lower than in corresponding mycorrhizal treatments in both cases. Malonic acid was found in the culture solution of non-mycorrhizal had P. involutus-colonized seedlings, but only trace amounts were found in S. variegatus or R. roseolus-infected seedlings. Citric, shikimic, lactic, acetic, propionic, fumaric, formic, iso-butyric and butyric acid were found in variable concentrations. Production of oxalic acid by seedlings ColoniZed by S. variegatus BL or P. involutus was not stimulated by exposure to 0.44 μM Cd or 17 μM Ni. Exposure to 0.157 mM CU in two separate experiments using P. involutus 87.017 and two strains of S. variegatus (BL and 159) appeared to stimulate production of oxalic acid irrespective of mycorrhizal status or species.

567891011 351 - 400 of 26559
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf