• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 271
  • 130
  • 71
  • 45
  • 40
  • 20
  • 19
  • 15
  • 15
  • 12
  • 11
  • 10
  • 7
  • 4
  • 4
  • Tagged with
  • 787
  • 72
  • 65
  • 54
  • 52
  • 44
  • 44
  • 44
  • 43
  • 42
  • 33
  • 30
  • 30
  • 30
  • 29
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

APPRENTICESHIP, CULTURAL TRANSMISSION AND THE EVOLUTION OF CULTURAL TRADITIONS IN HISTORIC NEW ENGLAND GRAVESTONES

Scholnick, Jonathan January 2010 (has links)
Cultural evolutionary models that relate spatial and temporal patterning in artifact sequences to human social learning processes and history have made many recent advances. Specifically, these models connect evolutionary forces and social leaning mechanisms along cultural pathways with expectations that can be assessed using material culture. In this dissertation, I use an historical archaeology case study of carved New England gravestones to evaluate three different aspects of cultural transmission and artifact patterns. First, I study the role of social network structure in the transmission of cultural information among carvers organized in workshops that were principally comprised of a carver and his apprentices. The results of this study suggest that the motifs reflect widespread similarity that transcends workshop organization. However, the finer grained decorative elements that make up these motifs correspond with cultural lineages of gravestone carvers. Second, I examine the relationship between the diffusion of innovations and cultural transmission mechanisms that result in spatiotemporal patterning. The spatial patterning suggests that social contagion among consumers created brief instances of wave-like diffusion from a distinct workshop, highlighting the role of consumer choice. A review of probate payments shows that gravestones were rarely purchased from distance sources, as transport costs could be prohibitive. The spatial patterning and historic record suggest that carvers also learned from other carvers creating a hierarchical diffusion process. These two populations created a feedback mechanism that leads to complex emergent phenomena, as illustrated by the rapid and widespread adoption of the cherub motif. Third, the neutral model of stylistic variation is applied to gravestone data to examine the ways that increased consumption and an expanding carving industry led to dominant decorative motifs. This study shows that neutrality can be a fleeting and transitional state between the dominance of single decorative styles. These three studies use New England gravestones to illustrate the evolutionary forces and cultural transmission mechanisms among artifact producers and consumers, which generated the stylistic patterning we observe in the archaeological record.
72

3D PDF

Håkansson, Filip January 2008 (has links)
This report is about Adobe Acrobat 3D and their new PDF format witch can contain 3 dimensional models that are interactive. The purpose is to find out if the program and the format work in a level that is suitable for the market. To create this PDF you need Acrobat 3D installed on your computer but it only needs Acrobat Reader 7 or 8 to open it, and the Reader is free to download on the internet. The examination is focusing on four formats: U3D, 3DS, DWG and DXF because they are the most common in the building industry seen from the architects’ way. From a 3D model exported to these four formats they where converted to PDF in different settings to be compared in different points as information and size of the files. The result where put together in tables for an easy overview. During the work there were no big differences between the results from the different settings noticed. The differences depended more from which format the PDF where converted from. Then the program is not that old on the market there are still some things that can be improved.
73

Plastic phenotypic responses of the sea star Pisaster ochraceus to spatial and temporal variation in wave exposure

Hayne, Kurtis Unknown Date
No description available.
74

Slavhandel och slaveri i svensk 1800-talspress : En pressundersökning om hur slavhandel och slaveri framställs i tre svenska dagstidningar mellan 1840-1860 / Slave trade and slavery in 19th century Swedish newspapers : A study of how slave trade and slavery were depicted in three Swedish daily newspapers between 1840 and 1860

Cook, William January 2014 (has links)
The transatlantic slave trade started in the 17th century and lasted for more than two hundred years, and many nations across the world abolished the slave trade during the 19th century. As slavery became a rather controversial topic, it led to hectic debates about the moral aspects of buying and selling human beings. During the 19th century in North America, newspapers were used to influence people and make them aware of the contemporary slave trade. Ideas and thoughts about the slave trade were conveyed to the public through newspapers, which became important and widely used media phenomena. Newspapers have always been used to convey different kinds of information, and as slavery was a much-disputed topic, the newspapers frequently wrote about it. This study aims to give an analysis of how three 18th century Swedish newspapers – Folkets röst, Jönköpingsbladet and Post- och inrikes tidningar – depicted the slave trade and slavery in general, between 1840 and 1860. In each newspaper, 15 news articles were analysed. The results show that the number of news articles where slavery was depicted in a negative context in Folkets röst and Post- och inrikestidningar, the results were approximately the same. As for Jönköpingsbladet, slavery was depicted in primarily neutral contexts. Neither of the newspapers depicted slavery positively.
75

Impurity transport studies on Alcator C-Mod tokamak using charge exchange recombination spectroscopy

Bespamyatnov, Igor Olegovich, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
76

The thickness of the HI gas layer in spiral galaxies

Sicking, Floris Jan. January 1997 (has links)
Thesis (Ph. D.)--Rijksuniversiteit Groningen, 1997. / Includes bibliographical references.
77

Neutral density profiles in argon helicon plasmas

Keesee, Amy M. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains v, 218 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
78

The development of sialidase inhibitors using structure-based drug design

Rogers, Graeme W. January 2017 (has links)
The sialidases/neuraminidases represent a family of enzymes whose function is important in the pathogenicity of bacteria and the virulence of influenza. Relenza and Tamiflu represent two drugs that were developed using structure-based drug design (SBDD) and computational-assisted drug design (CADD). These drugs target the active site of the influenza neuraminidase A and B (GH-34 family). Sialidases in the GH-33 family could represent novel drug targets for the treatment of bacterial or parasitic infection. SBDD was employed to develop chemical tools of two GH-33 sialidases, NanB and TcTS. NanB is a potential drug target for S. pneumoniae. The chemical tool developed for NanB follows on from work within the Taylor and Westwood research groups, in which a molecule of CHES and a glycerol were found serendipitously bound within a water channel at an allosteric site. Using this information as a basis for SBDD an allosteric inhibitor of NanB, Optactin was developed. Within this work, synthesis of this inhibitor was achieved and optimised. Optactin was then modified to improve potency. This proceeded through an amide analogue and addition of an arene resulting in a mid- micromolar inhibitor (IC50: 55.4±2.5 μM). Addition of polar substituents improved potency further resulting in a low micromolar inhibitor of NanB, Optactamide (IC50: 3.0±1.7 μM). Application of this tool in vitro demonstrated that NanB and NanA have a role in invasion of S. pneumoniae into lung epithelial cells. TcTS is a potential drug target for the treatment of Chagas disease. A CADD approach using a fragment library was unsuccessful at identifying an allosteric inhibitor of TcTS despite structural similarity with NanB. A re-task of the CADD approach towards the active site was successful in identifying an inhibitor of TcTS and a fragment useful for further development. This work sets the groundwork for the development of a chemical tool targeting TcTS.
79

Opartisk undervisning? : F-3-lärare som demokratiska och religiöst/partipolitiskt neutrala ledare

Söderberg, Anette January 2018 (has links)
Detta självständiga arbete handlar om hur läraren ser på sin roll som religiöst och partipolitiskt neutrala ledare. Bakgrunden till denna studie har uppkommit genom debatterna kring luciafirandets vara eller icke vara. Hur kan lärare vara objektiva och neutrala i sin undervisning när det alltid är mycket runt omkring oss som det debatteras om?   I studien framkommer det att vara neutral är viktigt men att det finns tillfällen då läraren kan behöva säga sin mening, vilket gör att läraren frångår sin neutralitet. Syftet är att se hur läraren ser på sin egen roll som objektiv och neutral ledare när det kommer till religiösa och politiska frågor. För att komma fram till ett resultat har jag använt mig av intervjuer. Det som har framkommit är att det är viktigt att vara neutral men att det finns vissa undantag då det gäller grundvärderingarna och mänskliga rättigheter. Det vill säga att lärarna ger sina personliga uppfattningar så länge de står i samklang med skollagen.
80

Simulação computacional aplicada à melhoria do processo de purificação de bioetanol = Computational simulation applied to the improvement of the bioethanol purification process / Computational simulation applied to the improvement of the bioethanol purification process

Batista, Fabio Rodolfo Miguel, 1978- 21 August 2018 (has links)
Orientador: Antonio José de Almeida Meirelles / Texto em português e inglês / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-21T10:31:20Z (GMT). No. of bitstreams: 1 Batista_FabioRodolfoMiguel_D.pdf: 2503364 bytes, checksum: 981f60d79f8a7a65e7ab2c5b944ab1d7 (MD5) Previous issue date: 2012 / Resumo: A diminuição gradativa das reservas de combustíveis fósseis e a crescente preocupação com os efeitos do aquecimento global vêm impulsionando cada vez mais as pesquisas por fontes de energia limpa. Dentre essas energias, o etanol de cana-de-açúcar, utilizado no Brasil desde a criação do Programa Nacional do Álcool (PROALCOOL) em 1975, vem se consolidando cada vez mais e sofrendo modificações contínuas no seu processo produtivo. Essas modificações se devem,entre outros aspectos, ao surgimento do conceito de biorrefinaria, que visa um aproveitamento integral da biomassa da cana para produção de energia, e ao rápido e contínuo crescimento da indústria alcoolquímica brasileira, utilizando o etanol como matéria prima para a produção de diversos outros produtos,aumentando a demanda por etanol de melhor qualidade e impulsionando pesquisas no melhoramento do processo produtivo atual. Tendo em conta esse atual cenário, essa tese tem por objetivo estudar o processo de destilação alcoólica industrial, por simulação computacional, analisando a influência dos diversos contaminantes do fermentado de cana no funcionamento das colunas de destilação, investigando a possibilidade do desenvolvimento de uma nova planta industrial para a produção de álcool carburante e álcool neutro, um tipo especial de álcool de alto valor agregado com baixo teor de contaminantes utilizado na indústria de química fina e de bebidas. Para o cumprimento desse objetivo, esta tese está dividida em 6 capítulos: o Capítulo 1 apresenta uma revisão bibliográfica da produção científica associada à produção de álcool combustível, apontando as principais lacunas inerentes a esse tema; o Capítulo 2 discute a produção industrial de cachaça por sistema contínuo apresentando um cuidadoso estudo do equilíbrio de fase dos principais componentes do fermentado de cana de açúcar e analisando a influência dos mesmos no processo produtivo; o Capítulo 3 e o Capítulo 4 apresentam o estudo do processo de produção de álcool hidratado combustível discutindo a influência dos componentes do vinho no funcionamento das colunas, técnicas de otimização de processo aplicadas a um processo industrial real e técnicas de controle de processo aplicadas ao controle de acetaldeído e da graduação alcoólica no bioetanol; o Capítulo 5 apresenta uma nova planta industrial para produção de álcool neutro e álcool hidratado discutindo detalhadamente as vantagens e desvantagens do novo processo frente a plantas industriais tradicionais brasileira e francesa; por fim, o Capítulo 6 apresenta as conclusões gerais do trabalho sugerindo temas para investigações futuras. A análise dos resultados obtidos permitiu conluir que, ainda que consolidado, o processo produtivo de etanol através de cana-de-açúcar apresenta lacunas importantes, principalmente quando se deseja produzir etanol de qualidade superior. Nesse sentido, uma nova planta industrial foi proposta com o objetivo de produzir etanol neutro e hidratado em uma única instalação com redução nos custos de instalação (menor numero de colunas) e de consumo de vapor / Abstract: The gradual reduction of fossil fuel reserves and growing concerns about the effects of global warming have encouraged more research on clean energy sources. Among these energies, ethanol from sugar cane, used in Brazil since the creation of the National Alcohol Program (PROALCOOL) in 1975, has undergone continuous changes in their production process. These changes were due to the emergence of the concept of biorefineries, aiming at a full utilization of sugarcane biomass for energy production, and the continuous and quick growth of the Brazilian alcohol-chemical industry, using the ethanol as raw material for the production of several other products, increasing the demand for ethanol with better quality and boosting the research to improving the current production process.Taking into account this present scenario, this thesis aims to study an industrial process for ethanol production, by computational simulation, analyzing the influence of the contaminants of the fermented sugar cane in the operation of distillation columns, investigating the possibility of developing a new plant for the industrial production of fuel alcohol and neutral alcohol, a particular type of hydrated alcohol of high economic value and low content of contaminants used in the manufacture of fine chemicals and beverages. To fulfill this objective, this thesis is divided into six chapters: Chapter 1 presents a literature review of scientific literature related to the production of fuel alcohol, pointing out the main shortcomings inherent in this theme; Chapter 2 discusses an industrial process for cachaça production by continuous distillation featuring a careful study of the phase equilibrium of the main components of the fermented sugar cane and analyzing their influence in the production process; Chapter 3 and Chapter 4 presents the study of an industrial plant for hydrated fuel ethanol production discussing the influence of the main components of the wine in the columns operation, techniques of process optimization applied to a real industrial process and techniques of control process applied to the control of acetaldehyde and alcoholic graduation in bioethanol; Chapter 5 presents a new plant for neutral and hydrated alcohol productions, discussing in detail the advantages and disadvantages of the new process compared to traditional Brazilian and French industrial plants; finally, the Chapter 6 presents the overall findings of the study and suggesting topics for future investigations. Taking into account the results of this thesis, was possible to concluded that, although consolidated, the ethanol production process using sugar cane as raw material presents important gaps especially when related with high quality ethanol. Some of these shortcomings were solved by proposing a new industrial configuration in order to produce neutral and hydrated ethanol in a single installation with lower installation costs (less number of columns) and steam consumption / Doutorado / Engenharia de Alimentos / Doutor em Engenharia de Alimentos

Page generated in 0.0457 seconds