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  • 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.
1

Radioaktyviųjų teršalų paplitimo atmosferoje įvertinimas / Evoluation of the radiological pollutants discharge into the atmosphere

Zabitytė, Jurgita 16 August 2007 (has links)
Šio darbo pagrindinis tikslas − įvertinti radioaktyviųjų teršalų paplitimą atmosferoje ir nusėdimą, bei įvertinti teršalų žalą aplinkai ir žmonėms. Tam tikslui pasiekti, šiame darbe buvo: 1.išanalizuoti pagrindiniai radioaktyviųjų teršalų paplitimo būdai; 2.supažindinta su teisės aktais ribojančiais radionuklidų išmetimą į aplinką; 3.įvertinti labiausiai žmonių sveikatą įtakojančių radionuklidų ir sklidimą atmosferoje ir nusėdimą. / In Lithuania we have a very important object from the point of energetics. It’s atomic power − station of Ignalina. It is work safety aspects worry so the themes of the graduate work have been chosen for this clean reason. The base of the work is to evaluate the damage of the radiological nuclides and to the environment and people and their discharge amounts the atmosphere, if it doesn’t exceed allowable norms, witch are regulated by the laws of Lithuania Republic. Willing to introduce you to this theme the following objectives were defined: 1.The main ways of radiological pollutants discharge into the atmosphere have been analyzed; 2.Have been familiarized with the main norms of radiological safety and the limitation of the discharge of radio nuclides into the atmosphere from the objects of atomic energetics; 3.According to the push − button program of environment pollution “ Hysplit ” the distribution of the radiological nuclides in the atmosphere has been denoted; 4.According to the results having been done by the program “ Hysplit “, the diagram of the dependence of the nuclides and on time has been delineated. It is clear that the atmosphere doesn’t exceed allowable norms of the laws of Lithuania Republic. It’s even lower than allowable norms per day. In conclusion, having all the objectives of this work analyzed it becomes clear that the amounts of the nuclides and witch gets into the atmosphere doesn’t damage our organisms and environment.
2

Molybdenum Disulfide as an Efficient Catalyst for Hydrogen Evolution Reaction

Alarawi, Abeer A. 02 December 2018 (has links)
Hydrogen is a carrier energy gas that can be utilized as a clean energy source instead of oil and natural gas. Splitting the water into hydrogen and oxygen is one of the most favorable methods to generate hydrogen. The catalytic properties of molybdenum disulfide (MoS2) could be valuable in this role, particularly due to its unique structure and ability to be chemically modified, enabling its catalytic activity to be further enhanced or made comparable to that of Pt-based materials. In general, these modification strategies may involve either structural engineering of MoS2 or enhancing the kinetics of charge transfer, including by confining to single metal atoms and clusters or integrating with a conductive substrate. We present the results of synergetic integration of MoS2 films with a Si-heterojunction solar cell for generating H2 via the photochemical water splitting approach. The results of the photochemical measurements demonstrated an efficient photocurrent of 36. 3 mA cm-2 at 0 V vs. RHE and an onset potential of 0.56 V vs. RHE. In addition to 25 hours of continuous photon conversion to H2 generation, this study points out that the integration of the Si-HJ with MoS2 is an effective strategy for enhancing the internal conductivity of MoS2 towards efficient and stable hydrogen production. Moreover, we studied the effect of doping an atomic scale of Pt on the catalytic activity of MoS2. The electrochemical results indicated that the optimum single Pt atoms loading amount demonstrated a distinct enhancement in the hydrogen generating, in which the overpotential was minimized to -0.0505 V to reach a current density of 10 mA cm−2 using only 10 ALD cycles of Pt. The Tafel slopes of the ALD Pt/ML-MoS2 electrodes were in the range of 55–120 mV/decade, which indicates a fast improvement in the HER velocity as a result of the increased potential. Stability is another important parameter for evaluating a catalyst. The same (10 ALD cycles) Pt/ML-MoS2 electrode was able to continuously generate hydrogen molecules at for 150 hours. These superior results demonstrate that the low conductivity of semiconductive MoS2 can be enhanced by anchoring the film with Pt SAs and clusters, leading to sufficient charge transport and a decrease in the overpotential.
3

Staphylococcal surface display in directed evolution

Kronqvist, Nina January 2009 (has links)
Engineered affinity proteins have together with naturally derived antibodies becomeindispensable tools in many areas of life-science and with the increasing number ofapplications, the need for high-throughput methods for generation of such different affinityproteins is evident. Today, combinatorial protein engineering is the most successful strategy toisolate novel non-immunoglobulin affinity proteins. In this approach, generally termed directedevolution, high-complexity combinatorial libraries are created from which affinity proteins areisolated using an appropriate selection method, thus circumventing the need for detailedknowledge of the protein structure or the binding mechanism, often necessary in more rationalapproaches. Since the introduction of the phage display technology that pioneered the field ofcombinatorial engineering, several alternative selection systems have been developed for thispurpose.This thesis describes the development of a novel selection system based onstaphylococcal surface display and its implementation in directed evolution approaches. In thefirst study, the transformation efficiency to the gram-positive bacteria Staphylococcus carnosus wassuccessfully improved around 10,000-fold to a level that would allow cell surface display ofcomplex combinatorial protein libraries. In two separate studies, the staphylococcal displaysystem was investigated for the applicability in both de novo selection and affinity maturation ofaffibody molecules. First, using a pre-selection strategy with one round of phage display, ahigh-complexity affibody library was displayed on staphylococcal cells. Using fluorescenceactivatedcell sorting, binders with sub-nanomolar affinity to tumor necrosis factor-alpha(TNF-α) were isolated. Second, a combined approach using phage display for de novo selectionof first-generation affibody binders and staphylococcal display in a subsequent affinitymaturation selection was applied to generate binders with low nanomolar affinity to the humanepidermal growth factor receptor-3 (ErbB3). Moreover, in an additional study, thestaphylococcal surface display system was improved by the introduction of a protease 3Ccleavage sequence in the displayed fusion products in order to facilitate straightforwardproduction of soluble proteins for further downstream characterization.Altogether, the presented studies demonstrate that the staphylococcal selection systemindeed is a powerful tool for selection and characterization of novel affinity proteins and couldbecome an attractive alternative to existing selection techniques. / <p>QC 20100726</p>
4

Zvyšování efektivity pracovního výkonu ve vybrané firmě / Increasing efficiency of work performance in selected company

Hejlová, Marie January 2017 (has links)
The thesis deals with increasing the efficiency of work performance in Favi online s.r.o. The main objective is to find out which factors affect the efficiency of work performance and propose optimization measures as to how the company can stimulate employees to increase work performance. The theoretical chapter defines the main terms of the thesis, work performance, managing of work performance and motivation. The reader is also introduced to the stated issue. The main objective of this thesis is to capture the work performance of Favi online s.r.o. and its evaluation and remuneration. The final section includes data interpretation and proposes optimization measures to increase efficiency of work performance.
5

A genese da composição de um material didatico para ensino-aprendizagem de portugues como segunda lingua / The genesis of developing a textbook for Portuguese as a second language

Gottheim, Liliana, 1955- 06 June 2007 (has links)
Orientadores: Jose Carlos Paes de Almeida Filho, Brian Tomlinson / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-08T21:46:02Z (GMT). No. of bitstreams: 1 Gottheim_Liliana_D.pdf: 35311287 bytes, checksum: b1ef646971b60466ed2a506f9b6ea582 (MD5) Previous issue date: 2007 / Resumo: O objetivo, deste trabalho, foi estudar o processo de composição de um material didático em abordagem comunicacional para um curso de PLE (de 35-40 horas). O material foi construído com o propósito de propiciar momentos de uso de língua na comunicação, por meio de conteúdos da formação social e histórica da população brasileira. A ênfase deste estudo situou-se no entendimento da concepção de produção da autora, ou seja, no que ¿fez acontecer¿ certas ações na sala de aula, numa tentativa de explicitar os conhecimentos formais e informais envolvidos na produção de textos e atividades. A primeira versão desse material surgiu em trabalho de Mestrado (1994-1996) e a segunda, no Doutorado (2004); ambas elaboradas para alunos que já possuíam um nível mínimo de proficiência, suficiente para interpretar e produzir textos versados sobre o tema escolhido. A curiosidade para produzir um material alicerçado em conhecimentos teóricos hoje disponíveis e investigar esse processo partiu da dificuldade de entender como ¿autores produzem livros¿. Dois eixos permearam a narrativa e discussão desse trabalho: um de avaliação de MD, que possibilitou explicitar os conhecimentos formais e informais envolvidos na produção do material, assim como as atitudes tomadas; e outro, de produção, que permitiu estudar como formas de ação foram criadas segundo aqueles conhecimentos. Acrescemos à pesquisa dados da implementação do material e informação coletada com sete outros autores acerca de suas concepções próprias em obras que produziram. A metodologia utilizada foi a da pesquisa-ação, cujo foco num primeiro momento foi a tomada de conscientização de aspectos que envolveram a produção daquele material, para depois associar as exigências sentidas, à mobilização de modificações em um nível do ¿fazer¿, superando empecilhos encontrados. Além de sinalizar conhecimentos significativos à produção de um material, os dados mostraram padrões comuns e singulares à gênese de nossa composição e à dos sete autores analisados. Os resultados permitiram-nos apontar possíveis fatores de sucesso à produção de novos materiais e destacar a necessidade de se obter clareza das reais funções do autor na produção de materiais-fonte e do professor na condução desses materiais nas aulas (já menos difusas) para poder direcionar ações tanto de produção de obras como de preparação à docência em abordagem comunicacional. Dessa forma, poderemos modificar antigos papéis acríticos de subordinação e dependência do professor aos textos e atividades propostos em livros e incentivar o desenvolvimento da requerida autonomia do professor e a tomada de risco para novas produções / Abstract: The objective of this thesis was to study the process implicated in the development of a textbook of Portuguese for foreigners, which was built in accordance with the principles of the communicative approach in language teaching and intended for a 35- to 40-hour course. The textbook was organized around six topics dealing with the social and historical scenery at the time of the discovery of Brazil, focusing mainly on the ethnic groups that have contributed to form today¿s Brazilian population. The material was planned for students at an intermediate level of language who had already acquired enough language knowledge to interpret and produce short texts about the chosen content. This research was partly an attempt to make explicit the formal and informal knowledge and attitudes involved in gathering texts and creating learning activities for our material, and also an attempt to discuss the difficulties encountered in applying theoretical knowledge in AL to the production of materials. There were two versions of the same book used in this study: a first version done during our Master¿s course (1994-1996) and a second one which came out reformulated in the PhD programme (2004). The research was motivated by our interest on understanding ¿how authors produce books¿ with the purpose to shed some light on the production of materials based on recent theoretical knowledge. The methodology used for this study was the action-research through which we gained consciousness of many aspects involved in the process of producing textbooks. Some data collected from piloting the material in class relevant to the materials¿ design, was added to the research, plus data from interviews which we conducted with seven authors who talked about their own conceptions on producing textbooks. Besides signalizing some relevant aspects of our conception of production in the two versions of the same book, this study showed the common and distinctive patterns of the genesis of composing textbooks by different authors. The results pointed to possible factors of success in producing materials for PFL and made salient the necessity of obtaining clarification of the real role of the authors when producing support materials and of teachers when they apply them in class. Thus we direct actions not only to the production of textbooks in the communicative approach, but also to teacher¿s education. We hope that this research can help teachers reflect on ways to modify old roles of dependence on textbooks and encourage the development of their autonomy and attitudes of the risk taking needed for teacher¿s actions to be performed in alignment with this approach / Doutorado / Lingua Estrangeira / Doutor em Linguística Aplicada

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