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Uttorkning av betongbjälklag : En utmaning och en möjlighet / Drying of concrete flooring : A challenge and a possibilityBergström, Louise January 2017 (has links)
Betong har länge varit det mest använda byggnadsmaterialet. Dess goda beständighet, formbarhet och hållfasthet har gjort att den till ett av våra viktigaste byggnadsmaterial. Uttorkningen av betongbjälklagen är en del av ett projekts kritiska linje eftersom det inte är möjligt att applicera golvbeläggningen innan detta moment är utfört. JM inledde 2016 ett pilotprojekt där man istället för utfackningsväggar prövade att använda prefabricerade betongytterväggar, vilket förkortar produktionsledtiden och gör att huset blir tätare. I samband med detta väcktes frågan om hur de prefabricerade betongväggarna påverkade uttorkningen av betongen. Detta examensarbete syftar till att undersöka hur JM arbetar med uttorkningen av betongbjälklag och att utreda vad JM kan göra för att undvika att betonguttorkning blir ett problem för byggarbetsplatserna. För att ta reda på hur JM arbetar med uttorkning av betongbjälklag intervjuades platschefer och arbetsledare. Intervjuerna visade att platsledningen upplever att betonguttorkningen utgör ett problem i vartannat till vart tredje projekt och att det skulle behöva fokuseras betydligt mer på den. De visade även att de som arbetar med betongen har god kunskap om uttorkning av betong och eventuella åtgärdsmetoder om torkningen går för långsamt. Hur betonguttorkningen hanteras beror dock till stor del på platsledningens erfarenhet. När ett projekt påbörjas görs en fuktdimensionering av BetongIndustri som visar vilken betongkvalitet som krävs för att betongen ska hinna torka till den önskade relativa fuktigheten under utsatt tid. Den visar även om det finns en risk att det uppstår problem någonstans. Det finns dock flera moment som kan leda till att det senare uppstår problem, t.ex. simuleras inte nederbörd på ett verklighetstroget sätt i beräkningsprogrammet, det är problematiskt att olika definitioner används och frånvaro av tydliga riktlinjer kring ventilation ökar risken för att det missas eller startas för sent. En mätning utfördes även av den relativa fuktigheten i ett torkande bjälklag på projektet Berghus 3 i Liljeholmen i Stockholm. Mätningarna visade att betongen i princip inte torkar alls innan huset är tätt och värmen slagits på. Mätningarna visade även att torkklimatet i byggnaden endast under en kort period befinner sig inom det intervall som uttorkningen beräknats för. Det finns åtgärder för att motverka problem med torkningen uppstår. Genom att undvika nederbörd och stående vatten på bjälklagen får betongen bättre förutsättningar och kan torka snabbare. För att säkerställa att omgivningen uppfyller det som krävs för att betongen ska torka ut behöver torkklimatet kontrolleras och det behövs även en beredskap för hur torkinsatser ska ske vid för långsam torkning.
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Electromagnetic Shielding of Fine Wires for Electrophysiological Sensing / Elektromagnetisk skärmning av tunna trådar förelektrofysiologiska mätningarMogren, Simon January 2020 (has links)
Tests have been performed to determine whether electromagnetic shielding of fine wires for electrophysiological sensing is a possible way to reduce the external noise in recording of nervous signals. By shielding the wires with a layer of silver, forming a coaxial cable, a reduction of the received power on the lead of 11.8-33 dBm was shown over the 10 – 10 000 Hz range when the test wire was subject to an electromagnetic field from an injection cable. When putting the performance on the interval 50-100 Hz aside the same performance was measured to 25-33 dBm lower received power, which can be explained by 50 Hz noise from the electrical grid interfering with the measurements. However, when the shield was not grounded or grounded through a resistor worse performance was shown. The difference in received power between the unshielded and shielded configuration without grounding the shield was close to 0 dBm. Following this, the type of shielding investigated in this project has the potential to substantially shield thin wires from external interference under the condition that sufficient grounding is provided.
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Design of column bases concerning bending and shear nibs / Dimensionering av pelarfötter med beaktande av böjning och dymlingKay, Rodi January 2021 (has links)
The purpose of the thesis is to find out how to design column bases with conventional methods presented by European standards and codes, but above all from the Steel Construction Institute's handbook on structural joints and compare it with finite element analyses. However, today there are no good instructions for how column bases exposed to multiaxial bending should be designed, where assumptions based on structural mechanics also was compared with computer tools. The hand calculations are made in Excel and are something Northpower Stålhallar AB has requested, which will facilitate their work with design of column bases for VKR profiles placed at the middle, along one side, and at the corner of the plate. Several examples of column bases are touched upon in the work, with different load effects, as well as different dimensions of the column base, to assess how the result is affected. Examples of a dowel's bearing capacity are also treated. Finally, the calculations do not differ significantly from the results of the FE analysis at the smaller dimensions of the column foot, and that difference lies on the safe side with both uniaxial and multiaxial bending, as well as for transverse force capacity. The deviation for multiaxial bending was considerably larger, as the calculations were based on assumptions. The problem is that when bending in two directions, it is uncertain where the pressure resultant is located as the magnitude of the bending moment significantly affects the point of attack, while for uniaxial bending it can always be assumed that it is at the flanges.For the larger dimensions, however, it was the opposite, the FE analysis was on the safe side compared to the manual calculations. This makes the result extremely uncertain. The capacity differs at different dimensions of the column foot. The conclusion is that more calculations need to be made, as only a few were examined in this thesis, but based on these results, it is not appropriate to use manual calculations if it is this uncertain. When using a shear dowel, the tensile force on the anchor rods became significantly lower for the FE analysis, this is assumed to be due to the secondary force Nsec.Ed who can be added for design, which was neglected in the manual calculations. / Examensarbetets syfte är att ta reda på hur man dimensionerar pelarfötter med konventionella metoder som ingår i europeiska standarder och föreskrifter, men framför allt från Stålbyggnadsinstitutets detaljhandbok, och jämföra det med finita elementmetoden. Idag finns det dock inga anvisningar för hur pelarfötter utsatta för fleraxlig böjning skall dimensioneras, där antaganden också jämförs med datorverktyg. De analytiska beräkningarna är framställda i Excel och MathCad och är något Northpower Stålhallar AB har efterfrågat, som skall underlätta deras arbete med dimensionering av pelarfötter för VKR-pelarprofiler placerade vid mitten, långsidan och hörnet av fotplåten.Flera exempel på pelarfötter berörs i arbetet med olika lasteffekter, samt olika dimensioner på pelarfoten, för att bedöma hur resultatet påverkas. Ett exempel på en dymlings bärförmåga behandlas också. Slutligen är det tydligt att handberäkningarna inte differerar avsevärt från resultaten av FE-analysen vid den mindre dimensionen av pelarfoten, och den skillnaden ligger på den säkra sidan för handberäkningarna vid både enaxlig och fleraxlig böjning, samt för tvärkraftskapacitet. Avvikelsen för fleraxlig böjning var dock avsevärt större, då beräkningarna var baserade på antaganden. Problemet vid böjning i två riktningar är att det är osäkert vart tryckresultanten ligger då storleken av böjningarna påverkar angreppspunkten, medan för enaxlig böjning kan man alltid anta att resultanten är vid den tryckta flänsen.Med avseende på den större dimensionen var resultatet dock tvärtom, att FE-analysen låg på den säkra sidan gentemot handberäkningarna. Det här gör slutresultatet osäkert, då kapaciteten differerar vid olika dimensioner på pelarfoten. Slutsatsen är att det definitivt behöver göras fler beräkningar, då endast enstaka fall användes vid denna rapport, men utifrån resultatet från detta arbete är det inte lämpligt att använda handberäkningar ifall det är osäkert. Gällande dimensionering av en skjuvklack blev dragkraften på grundskruvarna betydligt lägre för FE-analysen, detta antas vara på grund av den sekundära kraften Nsec.Ed som kan användas vid dimensionering, vilket försummades vid handberäkningarna.
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The 21st Century Classroom: Technology as a Transformative Tool in Educational Routines, Rules, and RitualsRizk, Jessica January 2018 (has links)
This dissertation discusses a current niche in sociological literature: technology and interaction rituals in elementary schools. In particular, it examines the relationship between classroom interactions and the increasing available new forms of technologies (i.e. iPads, robotics kits, Smart boards) that are finding their way into schools. In doing so, I consider what new interactions and digital tools might mean for student engagement in what has now become known as the “21st century classroom”. Two pivotal sociological theories are utilized in this project: 1) Collins (2004) interaction ritual (IR) theory and 2) Bourdieu’s (1974; 1986) concept of cultural capital. Both are valuable in understanding how the introduction of digital tools in mainstream schools can influence or change interactions between and among students and teachers in classrooms, how they may impact student engagement gaps. Traditionally speaking, schools have long valued and rewarded certain types of interactions—student obedience alongside teacher authority, an orderly and compliant classroom, emphasis on more traditional teaching and so forth. Student engagement was not necessarily a point of interest, as was having a systematic classroom. However, perhaps technology is beginning to change those valuations, and create new types of classroom interactions that are unique to the 21st century—classrooms that have a more student-centered pedagogy, whereby teachers work in tandem with students to engross them in the learning process, and where student engagement is more much valued. If this is true, this may be a sign of some new emerging types of IRs that are beginning to surface in the presence of technology.
Collins' (2004) theory of IR focuses on the emotional input and feedback of individuals that transpire in interactions among actors, which in the case of classrooms, consist of teachers and students. The theory holds that interactions produce or deplete “emotional energy” of participants depending on many key factors (physical co-presence, exclusivity of group, mutual focus/mood, bodily synchronization). A successful ritual is one in which participants have a mutual focus on a particular “symbol” or “emblem” unique to that group. Through this research, I propose that technology can serve as that “emblem” to group membership, and as a result, can facilitate new kinds of IR. “Cultural capital”, in comparison, is usually considered to be a collection of symbolic elements such as skills, tastes, clothing, materials, credentials and so on that one acquires by being a member of a particular social class. In education, cultural capital can refer to having valued sets of skills and knowledge that are aligned with school rewards. Traditionally, this usually meant a middle-upper class advantage in schooling, as students of more affluent families were able to learn valued kinds of skill sets to help them achieve better in school. However, with the advent of new technologies, I question whether notions of cultural capital have changed as a result, and whether possessing a digital skillset is in and of itself, a new type of valued capital. Can new technologies produce more equalizing experiences for students of varying SES backgrounds?
To explore the possibility of digital tools in classrooms creating new sets of rituals with new kinds of valued cultural capital, this study adopts a qualitative methodology, consisting of elementary classroom observations, interviews, and focus groups with teachers and students in ten school boards across Ontario, Canada. My research discusses three integrated themes. I begin by asking first, how have technologies transformed the ways in which students and teachers interact with, and amongst each other? By providing a new medium for both teacher pedagogy and student learning, this has major implications for classroom engagement. Secondly, I explore the possibility that one unintended consequence of using digital resources (compared to more traditional print media), has been a reduction in home-based inequalities, and a more “even playing field” for students of varying SES. With the ease, accessibility, and affordability of technology today, students in vary capacities are exposed to new valued skillsets. Lastly, I consider how technology can be a type of “leveler” for different kinds of students, which can allow them to participate and facilitate new types of ritual inclusions. I focus both on gendered interactions and exchanges between students with special needs as examples. The exploration of these three themes guides my research on the use of educational technologies across classrooms. These have important implications for sociologists, educational researchers, and policy-makers alike. / Thesis / Doctor of Philosophy (PhD)
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Effektivisering vid modellering av moduler med grupper och länkar i Revit / Improving effectiveness in modelling of modules by application of groups and links in Revit.Thulin, Isac January 2022 (has links)
In the construction industry there are different methods to manufacture a building. An effective method is to produce a modular building. In the making of modular houses, the module is built in a factory along with the building elements. Fixed furnishing and appliances are also completed in the factory. Modules are being used to reduce the building time on the construction site and reduce the risk of injuries. Revit is a BIM-software that is used in the making of three-dimensional digital models, quantities, and two-dimensional drawings. Parts of the work process in Revit can be streamlined if the software is used in the right way. When designing modules in Revit there are no distinct processes to work with, which can lead to delays during the design stage. In this work tests have been done to find a distinct way of working with design of modules in the basic design stage, modules with wooden joists and mirrored modules with wooden joists. The results of the tests show that it varies when the different methods should be used. To unique modular houses, where the modules do not need to be reused in other projects, it is most effective to use groups. When the modules need to be reused in other projects it is more effective to create the modules by working with links.
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Optimisation of several industrial and recently developed AJAM naphtha isomerization processes using model based techniquesJarullah, A.T., Abed, F.M., Ahmed, A.M., Mujtaba, Iqbal M. 24 April 2019 (has links)
Yes / Increasing the yield and research octane number (RON) of naphtha isomerization process are the most important issues in industries. There are many alternative industrial naphtha isomerization processes practiced around the world. In addition, AJAM is a new naphtha isomerization process proposed by the authors recently (Ahmed et al., 2018) where the isomerization reactor model was validated using real data of Baiji North Refinery (BNR) of Iraq. In this work, first, the performance of the AJAM Process is evaluated against 8 existing industrial isomerization processes in terms of RON, yield and the cost using model based optimisation techniques. To be consistent, we have used the same isomerization reactor model in all the industrial processes we evaluated here. Secondly, energy saving opportunity in the new AJAM process is studied using pinch technology.
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New Technologies in the Politics Classroom: Using Internet Classrooms to Support Teaching and Learning.Lee, Donna 29 May 2015 (has links)
no / This article introduces some ideas about using internet classrooms to enrich the experience of those learning and teaching politics. It draws and reflects upon my three-year experience of using internet classrooms to teach politics in optional and compulsory politics undergraduate modules, providing critical evaluation of the successes and problems involved. Much of what the article discusses can be applied to most, if not all, politics modules and will be useful to those wishing to use new technologies to support active learning strategies in their undergraduate teaching. The article is based on personal experience and student evaluations, rather than any rigorous research of learning outcomes. As such, I do not set out to prove that using internet classrooms has pedagogical advantages over using only traditional methods, and I am not arguing a case for or against using either.
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Tilläggsisolering med vakuumpanel för att uppnå EU-förslag om nollenergibyggnader år 2050 – En fallstudieGarmert, Jonas, Senanikhom, Kunyanut January 2024 (has links)
Ett förslag har lagts fram på att alla byggnader inom EU, såväl gamla som nya, ska uppnå nollenergistandard till 2050. Då en stor del av byggnadsbeståndet i Sverige består av äldre dåligt isolerade byggnader finns stort behov av förbättrad energiprestanda i befintliga byggnader. I detta arbete har potentialen hos vakuumisoleringspaneler (VIP) att bidra till förbättrad energiprestanda utvärderats. Som referensbyggnad används ett typiskt flerfamiljshus uppfört år 1957 i Gävle. Byggnaden har modellerats i Revit och energisimuleringar har gjorts i IDA-ICE och BV2 i syfte att analysera effekten av tilläggsisolering med vakuumpaneler, enskilt och i kombination med andra åtgärder. Resultatet visar på betydande potential för vakuumisoleringspaneler när det gäller att förbättra energieffektiviteten samt minska värmeförluster i byggnader. För att nå nollenergistandard måste dock tilläggsisoleringen kombineras med ett flertal andra åtgärder. / A proposal has been put forward that all buildings within the EU, old as well as new, should meet the demands for zero-energy buildings by 2050. Given that a considerable proportion of all buildings in Sweden are old and poorly insulated there is a great need for improved energy performance. This work evaluates the potential for vacuum insulation panels (VIP) to contribute to improved energy performance. A typical three-story apartment building from 1957 in Gävle, Sweden, is used as reference building. First the building was modelled in Revit, then energy simulations were run in IDA-ICE and BV2 in order to analyze the effect of adding vacuum insulation panels as extra insulation, in themselves and in combination with other measures. Results show a significant potential for vacuum insulation panels when it comes to improved energy performance and lowered heat loss of buildings. However, to fully reach zero-energy standards adding insulation in itself is not enough.
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Dewey, Disability, and Democratic EducationMullins Jr, Ricky Dale 22 April 2019 (has links)
This dissertation is comprised of three manuscripts that coalesce around the topics of Dewey, Disability, and Democratic Education. Each manuscript is formatted for publication and the dissertation itself is prefaced by information that explains my background and how it connects to my current research. As such, the work contained in this dissertation is a product of my experiences as a social studies teacher, special educator, and administrator. Henceforth, my work focuses on Dewey, Disability, and Democratic Education. My research interests culminate in a three-article dissertation. The first paper is entitled, "Using Dewey to Problematize the Notion of Disability in Public Education." A version of this paper is currently under review for publication. In this paper I situate Dewey's theoretical underpinnings in the conversation around special education. Previous scholars of Dewey and disability have examined the ways in which his work speaks to educational growth and educational opportunity; my work adds to this body of research. However, my work is unique in that not only do I discuss pluralistic, communicative, participatory democracy as it pertains to students with disabilities, I also examine how Deweyan democracy can take shape, specifically within the context of an Individualized Education Plan (IEP) meeting. I conclude by arguing that Deweyan democracy is not only ideal, but realistic, attainable, and necessary, especially in the lives of students with disabilities.
In my second paper, I use the Schools and Staffing Survey (SASS) dataset in a paper entitled, "Can We Meet Our Mission? Examining the Professional Development of Social Studies Teachers to Support Students with Disabilities and Emergent Bilingual Learners." A version of this paper has been accepted for publication in The Journal of Social Studies Research. In this work, I first examine the social studies scholarship looking at students with disabilities and emergent bilingual learners, as well as research about the nature of professional development within the social studies. I then analyze the number of students with disabilities and emergent bilingual learners that we support in the social studies to provide a portrait of the field. Next, I examine the extent to which social studies teachers receive professional development to support those student groups, as well as the extent to which the social studies teachers found the professional development to be useful. My findings indicate that social studies teachers do not receive substantial professional development to support the learning of all students, as evidenced by the limited amount of professional development received focusing on students with disabilities and emergent bilingual learners.
In my third paper, I build on previous research examining the possibilities and benefits of participating in informal learning spaces such as Twitter in a paper entitled, "'So I Feel Like We Were Theoretical, Whereas They Actually Do It': Navigating Twitter Chats For Teacher Education." A version of this paper is also under review for publication. In this paper, specifically, I examine the experiences and perceptions of pre-service social studies teachers who particip¬¬¬¬ated in a discipline specific Twitter chat known as #sschat. My findings indicate that pre-service teachers found value in the chat when they were able to share resources with practicing teachers and build professional learning networks. However, there were instances when the pre-service teachers felt like they contributed little because they did not have direct experience with teaching. Additionally, the pre-service teachers expressed dissatisfaction with using Twitter as a platform for professional chats. However, I still contend and conclude that the utility of such chats outweighs the negatives. Therefore, this study sheds light on the potentiality and necessity of utilizing Twitter chats as a space to provide ongoing and systematic support to pre-service teachers to help not only them, but the field of social studies education move forward. These papers when considered together form a foundation of scholarship and further inquiry focused on Dewey, Disability, and Democratic Education, on which I plan to build in the years to come. / Doctor of Philosophy / When I completed my undergraduate social studies teaching program, the job market appeared bleak in the coalfields of southwest Virginia. Coal, no longer king, had driven the economy for years. With its decline, my community barely managed to survive. My advisor at the time, honest and plain-spoken, told me that unless I obtained a license in special education, I would most likely not obtain a teaching job. Unlike many other areas of the country, in my hometown unless you could do other things like coach or drive a bus, a license to teach social studies was of little value. There was not much money and a new hire had to be willing to do many different jobs to prove his or her worth. Luckily, I had gotten my Commercial Driver License (CDLs) through a training program offered by the county school board, and I was consequently able to obtain a position, although not as a social studies teacher. I started my career in education as a special educator and substitute school bus driver. In this position I worked in an alternative education setting and taught vocational skills to secondary students with significant disabilities (in the institutional meaning of the word). From the start of my career, I aspired to become an administrator, so I enrolled in and completed a degree in Administration and Supervision. As I was working on that degree, I moved to the general education high school level, where I held a position teaching social studies and special education in an inclusive setting. Shortly thereafter, I obtained a job as an assistant principal. The part I enjoyed most about this position was working with and thinking about how to help teachers become better at their craft. At this point is when I decided to pursue a PhD in social studies education, so I could develop my interest into a body of research and eventually a career. Two years into my PhD program I was still grappling with who I was as a scholar. As I familiarized myself with social studies scholarship, I discovered that in my first position as an alternative education special educator, I was essentially preparing my students for the responsibilities of citizenship, which is the mission of the field of social studies (NCSS, 2013). Nevertheless, it was not until I started reading the work of John Dewey that I truly realized the complexity of what I experienced when I taught in the alternative education setting. That position allowed me to examine an element that I otherwise, would not have had the privilege to see; the complexity and intellect required for physical labor (Rose, 2004) and the inter-workings of true, vibrant, Deweyan democracy. Dewey’s work sparked a new interest in me and I started developing a deep-seated curiosity about how his theoretical underpinnings related to disability and democratic education. My interest in disability then caused me to ask other questions about social studies in relation to special education, which made me reflect on my prior experiences as a social studies educator. Although I had a license in special education, there were many instances in which I felt unprepared and unsupported in addressing the needs of all students in my classes which included general education students, students with disabilities (SWDs), and emergent bilingual learners (EBLs). I began to wonder if my feelings of unpreparedness and lack of support were in isolation. As I parsed the literature, I found that there was not a significant amount of research focused specifically on the extent to which social studies teachers felt they were prepared and supported to address the needs of all learners in their classroom. Additionally, my experience in both public education and teacher education gave me insight to realize that school systems do not have funding to provide specialized professional development and similarly, teacher education is under financial constraints as well. Therefore, I began examining what informal spaces such as Twitter offer educators in terms of professional support and development. My interests and curiosity fueled my scholarly work and eventually culminated into three distinct, but interconnected manuscripts. The three manuscripts that follow coalesce around my interests in Dewey, Disability, and Democratic Education.
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Critical Technologies: The United States Department of Defense Efforts to Shape Technology Development After the Cold War - A Discourse and Network AnalysisMcDonald, James Franklin Jr. 13 March 2014 (has links)
Each year the Department of Defense spends over $10 billion on its science and technology development efforts. While deemed an investment by proponents (and beneficiaries) technology development programs are particularly vulnerable in times of budget cuts. As the government moves forward with efforts to reduce spending the Department of Defense will be pressed to sustain current levels of spending on technology efforts. This situation is similar to the post-Cold War phase in defense planning when savings in spending were sought as a peace dividend. This dissertation examines the Department of Defense efforts during 1989-1992 to define certain technologies as critical to national security. Inherent in the effort to identify critical technologies was the desire to articulate technology ideology; to establish asymmetries of power and resources; and to patrol the boundaries of policy and responsibility. The questions are: What are the ideologies associated with technology development planning? What are the discursive mechanisms used to secure and reinforce power? And, what evidence of boundary work and network construction emerges from the examination? First, I distill from four years of defense technology planning documentation the explicit ideologies, the ideologies masked in metaphor, and the discourse strategies used to secure and sustain power. Following the deconstruction of the discursive elements I use Science and Technology Studies tools including boundary work, boundary objects, the Social Construction of Technology, and network theory, to further understand the heterogeneous process of defense technology development planning. The tools help explain the mechanisms by which elements of Department of Defense technology development form a connected structure. Finally, the examination yields a spherical network model for innovation that addresses the weaknesses of prior innovation network models. I conclude that in the face of uncertain budgets, technology planning relies upon ideology, power strategies, and boundary-work to build a network that protects funding and influence. In the current budget climate it will be interesting to see if the strategies are resurrected. The examination should be of interest to both the Science and Technology Studies scholar and the policy practitioner. And hopefully, the review will stimulate further examination and debate. / Ph. D.
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