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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.
61

Papel do gene da síndrome de Wiskott Aldrich (WASP) na leucemia mielóide crônica. / The role of Wiskott Aldrich syndrome protein (WASP) in the chronic myeloid leukemia.

Welbert de Oliveira Pereira 04 November 2011 (has links)
Bcr-Abl é a tirosina quinase (TK) responsável por causar a Leucemia Mielóide Crônica (LMC). Os últimos estudos de follow-up mostram que apenas 50% dos pacientes tratados com a segunda geração de inibidores de TK atinge a remissão completa, o que significa que metade desses pacientes necessita de um algo melhor do que está disponível. Wiskott Aldrich Syndrome Protein (WASP) é um gene essencial para o bom desenvolvimento e função das células hematopoiéticas. Ante esse contexto, decidimos investigar se WASP poderia ter algum papel ou relevância na LMC. Em conclusão, Bcr-Abl suprime a expressão WASP por um mecanismo epigenético. A re-expressão de WASP torna as células mais suscetíveis à apoptose em resposta ao Imatinib. Sugerimos que a recuperação da expressão WASP deve ser discutida como estratégia para a terapia da LMC. / Bcr-Abl is the tyrosine kinase (TK) responsible for causing Chronic Myeloid Leukemia (CML). This fusion protein up- and down-regulates several genes and pathways, producing a strong resistance to apoptosis and a blockage of cell maturation in the hematopoietic compartment. The last follow-up studies provided that only 50% of the patients treated with second generation achieve complete remission, what means that one-half of these patients needs something better. Wiskott Aldrich Syndrome Protein (WASP) is an essential gene for the proper development and function of the hematopoietic cells. In the light of this background, we decided to investigate if WASP could have some role or relevance in the CML context. In conclusion, Bcr-Abl suppresses WASP expression by an epigenetic mechanism. The re-expression of WASP makes the CML cells more susceptible to apoptosis and contribute to respond to Imatinib. We suggest that recovery of WASP expression should be discussed as a new and additional strategy for CML therapy.
62

Avaliação do comportamento de elementos traço essenciais e não essenciais em solo contaminado sob cultivo de plantas / Evaluation of the behavior of essential and non essential trace elements in contaminated soil under plants cultivation

Maria Ligia de Souza Silva 30 October 2006 (has links)
A contaminação do solo é crescente no mundo. Há grandes extensões de áreas contaminadas com elementos traço, compostos orgânicos, organometálicos e elementos radioativos, que ocorrem em concentrações que podem representar perigo ambiental. O comportamento dos elementos traço em solos e sua fitodisponibilidade com conseqüente passagem para a cadeia alimentar tem sido extensivo objeto de estudos mundialmente. Com o objetivo de avaliar o comportamento dos elementos traço, essenciais e não essenciais, num solo contaminado avaliou-se a absorção pelas plantas, a fitodisponibilidade por extratores e a fração do solo na qual os elementos encontram-se ligados em maior quantidade. O presente trabalho constou de dois experimentos, ambos realizados em casa de vegetação do Departamento de Ciência do Solo da ESALQ/USP com delineamento inteiramente casualizados, nos quais se utilizaram amostras de solo contaminado acidentalmente com elementos traço e espécies de plantas de interesse econômico. Os experimentos foram conduzidos de Novembro de 2004 a Abril de 2005, utilizando 7 níveis de contaminação por elementos traço e duas culturas, arroz e soja. Foi realizada adubação NPK de modo a atender as necessidades básicas de cada cultura. As plantas foram conduzidas até maturação. As variáveis avaliadas foram: desenvolvimento e produção vegetal; quantidade absorvida e acumulada de Cd, Cu, Fe, Mn, Pb e Zn; teores totais (água régia) e teores disponível dos elementos traço pelo uso das soluções Mehlich-1, HCl 0,1 mol L-1, DTPA e Ácidos Orgânicos no solo e a disponibilidade desses elementos através da correlação dos teores disponível no solo com os teores em folha diagnóstico, folha em final de ciclo e sementes de arroz e soja; e os teores de elementos traço nas frações do solo. A soja e o arroz foram sensíveis aos níveis de contaminação por elementos traço disponíveis no solo, exibindo sintomas de fitotoxidez, principalmente pelo Zn, manifestados por clorose e inibição do crescimento das plantas, sendo que o arroz mostrou-se mais sensível do que a soja à presença desses elementos. Para a soja, os quatro extratores foram eficientes para Cd, Cu, Pb e Zn, tanto ao correlacioná-los com teor na folha diagnóstico quanto na folha no final do ciclo enquanto que para o arroz, os mais eficientes foram o Mehlich-1, HCl 0,1 mol L-1 e o DTPA para o Cd, Cu, Fe e Zn. Para o Mn apenas o DTPA foi eficiente. Para o Fe, os extratores se mostraram pouco eficientes. O extrator Ácidos Orgânicos foi mais eficiente na avaliação da fitodisponibilidade de Cd, Cu, Pb e Zn para soja. Os maiores teores de Cd, Cu, Mn e Zn no solo encontram-se nas frações com ligações químicas mais estáveis (ligados a óxidos e residual) sendo as frações trocável + solúvel e orgânica de menor representatividade em relação ao total encontrado. O Pb, apesar de predominar nas frações ligadas a óxidos e residual, oferece grande potencial de contaminação ambiental por também apresentar-se nas frações trocável + solúvel e orgânica em teores consideráveis. O mesmo ocorre com o Zn, para o qual os teores totais foram mais elevados. / The contamination of the soil is growing in the world. There are great expanses of soil polluted with trace elements, organic compounds, organometals and radioactive elements that appear in concentrations that can endanger the environment. The behavior of trace elements in soils and its phytoavailability with subsequent transport to the alimentary chain has been quite intensive object of studies worldwide. With the objective of evaluating the behavior of essentials and non essential trace elements in a polluted soil, it was evaluated the absorption of trace elements by plants, its phytoavailability by extractors and in which fraction of the soil the elements are present in larger amount. The present work consisted of two experiments, both done entirely in a greenhouse of the Department of Soil Science of ESALQ/USP, with experimental design entirely randomized, in which samples of soil accidentally contaminated with trace elements and species of plants of economical interest were used. The experiments were conducted from November, 2004 to April, 2005, using seven levels of contamination for each trace elements and two cultures, rice and soybean. Fertilization with NPK was done in order to assist the basic needs of each culture. The plants were grown until maturation. The variables evaluated were: development and vegetable production; absorbed and accumulated amount of Cd, Cu, Fe, Mn, Pb and Zn; In the soil were determined total concentrations (HNO3/ HCl 1:3) and concentrations available of the trace elements by the use of the solutions Mehlich-1, HCl 0,1 mol L-1, DTPA and Organic Acids and the availability of those elements through the correlation of the available concentrations in the soil with the concentrations in diagnostic leaf, leafs in end of the cycle and seeds of rice and soybean; and the concentrations of trace elements in fractions of soil. The soybean and the rice were sensitive to the levels of trace elements available in the soil, exhibiting phytotoxicity symptoms, mainly for Zn, manifested as chlorosis and inhibition of growth. The rice was more sensitive than the soybean to the presence those elements. For soybean, the four extractors were efficient for Cd, Cu, Pb and Zn, both for the correlation with concentrations in the leaf diagnosis and in the leaf in the end of the cycle, while for rice, the most efficient were Mehlich-1, HCl 0,1 mol L-1 and DTPA for the Cd, Cu, Fe and Zn. For Mn, only DTPA was efficient. For Fe, the extractors were not efficient. The extractor Organic Acids was more efficient in the evaluation of the phytoavailability of Cd, Cu, Pb and Zn for soybean. The largest concentrations of Cd, Cu, Mn and Zn in the soil are found in the fractions with stable chemical bounds (attached to oxides and residue) being the exchangeable fractions + soluble and organic of smaller representativeness in relation to the total found. The Pb, in spite of prevailing in the fractions liked to oxides and residue, offers great potential of environmental contamination since it is also present in the exchangeable + soluble and organic fractions in considerable concentrations. The same happens for Zn, for which the total concentration was higher.
63

Radikalizace ve věznicích: Přístupy k problematice / Radicalization in Prison: Approaching the Issue

Dotlačil, Filip January 2019 (has links)
In recent years Europe experienced several terrorist attacks on its soil. Some of these were committed by Jihadists radicalised in prisons. An issue already identified by scholars has thus become publicly known and attracted attention of policy makers. The combination of Islamic propaganda with jails imprisoning substantial amount of vulnerable inmates and incarceration of returning foreign fighters create a mixture threatening to produce more violent extremists. The aim of this thesis is to describe how Germany approaches the issue and connect its solution with existing radicalisation models and prison regime concepts. Because of the federal structure of Germany, this description is based on analysis of three levels: institutional analysis of the German framework (macro); comparison of state projects tackling the issue (meso); and a case study of practitioners of one federal state (micro). The thesis comes to a conclusion, that the German strategy is strongly decentralised, still not in its final form, applies the concept of dynamic security as its prison regime and approaches the issue from a holistic perspective, involving also non-state actors and other areas of radicalisation.
64

Oxidation behavior of thermal barrier coating systems with Al interlayers

Ali, Ibrahim El Araby Megahed 03 May 2019 (has links)
Konventionelle Wärmedämmschichtensysteme bestehen aus einer Yttriumoxid-stabilisierten Zirkoniumdioxid-Deckschicht auf einer MCrAIY Haftschicht; wobei M für Co, Ni oder CoNi steht. Während der Nutzung bildet sich durch die Kombination von Wärme und Sauerstoff die Reaktionszone in der BC/TC-Grenzfläche. Diese Reaktionszone besteht aus thermisch wachsenden Übergangsmetalloxiden. In dieser Dissertation wurde das Phänomen der Bildung von TGO in TBC-Systemen betrachtet. Co32Ni21Cr8Al0.5Y Haftschichten wurden mithilfe des Verfahrens des atmosphärischen Plasmaspritzens (APS) auf Inconel 600 Substrate aufgebracht. Jm nächsten Schritt wurden durch DC-Magnetronsputter dünne Aluminumschichten auf die Oberfläche aufgetragen. Schließlich wurde YSZ TC mittels APS auf die Oberfläche gespritzt. Die beiden TBC-Systeme wurden zur Unterscheidung des Einflusses der thermischen Auslagerung unterschiedlich lange ausgelagert, um das thermochemischen Transformationsverhalten der Al-Zwischenschicht zu bestimmen. Die Schichtlebensdauer wurde unter thermischer Zyklierung mit einer definierten Verweilzeit untersucht. Das veränderte TBC-System mit der Al-Zwischenschicht (Al TBC) wurden mit dem TBC-System ohne Al-Zwischenschicht (R TBC) verglichen. Die Ergebnisse zeigen, dass das Hinzufügung der Al-Schichte in der BC/TC Grenzfläche nützlich für die Bildung der kontinuierlichen α Al2O3-Schicht während der Vorbereitungsphase der Wärmebehandlung ist. Diese dichte α Al2O3-Schicht bildet offensichtlich eine Durchgangsbarriere für den Sauerstoff während des Lebensdauertests. Dies hat Potential für die Verringerung der Bildung schädlicher Oxide. Der Ansatz ist nützlich für die Verlängerung der stabilen Wachstumsphase von TGO. In der Folge ermöglicht dies eine höhere Lebensdauer von Al-TBC-Systemen im Vergleich zu R-TBC-Systemen für die betrachteten thermischen Bedingungen und Zyklierungen.:Table of contents 1 Introduction 1 2 Motivation and overall interest 3 3 State of science and technology 5 3.1 Thermal barrier coating (TBC) systems 5 3.1.1 Substrate material 6 3.1.2 Ceramic top coating 6 3.1.3 Metallic bond coating 8 3.1.4 Thermally grown oxides (TGO) 12 3.1.5 Approaches on controlled TGO formation 15 3.1.6 Failure modes of TBC systems 17 3.2 Thermal spray technology 20 3.2.1 Atmospheric plasma spray (APS) technique 20 3.2.2 Formation sequence of the coating 21 3.2.3 Structure of the coating 22 3.3 Technology of thin layer deposition 23 3.4 Conclusions from the state of science and technology 24 4 Scientific objectives and work program 26 5 Experimental procedure 30 5.2 Material selection 30 5.3 Feedstock materials and thermal spray powders 32 5.4 Process selection 33 5.5 Specification of the scientific instruments 33 5.6 Detailed experimental procedure 34 5.6.1 Characterization of thermal spray powders 34 5.6.2 Preparation and characterization of overlaid coatings 35 5.6.3 Thermal treatment of TBC systems 39 5.6.4 Characterization of heat treated coating systems 40 5.6.5 Evaluation of TGO thickness and crack propagation 41 6 Results and discussions 43 6.1 Thermal spray powders and as sprayed coatings 43 6.1.1 Thermal spray powders 43 6.1.1.1 CoNiCrAlY thermal spray powder 43 6.1.1.2 ZrO2 – 8 %Y2O3 thermal spray powders 47 6.1.2 As-sputtered Al layer 50 6.1.2.1 Microstructure features 50 6.1.2.2 Elemental and phase composition analyses 50 6.1.3 As-sprayed coating systems 51 6.1.3.1 Bare and Al-covered CoNiCrAlY coatings 51 6.1.3.2 As-sprayed TBC systems 55 6.2 TBC systems after thermal treatment with different spans of dwell time 58 6.2.1 Thermal treatment with 5 and 30 min dwell time 58 6.2.2 Thermal treatment with 60 and 120 min dwell time 67 6.3 Lifetime test of TBC systems 68 6.3.1 Features in the cross section microstructure 68 6.3.2 Phase composition analyses 71 6.3.3 Elemental and Raman analyses 72 6.3.4 Features in the BC/TC of TBC systems after 80 thermal cycles 87 6.4 Thickness of TGO in the TBC systems 89 6.5 Length of cracks in the TC of the TBC systems 91 6.6 Relation between thickness of TGO and length of cracks 93 6.7 Discussion of loading condition and failure mode 95 6.8 Lifetime prediction of the TBC systems 97 6.9 Oxidation model of the TBC systems 98 7 Complementary work with discussion 100 7.1 Oxidation behavior of the TBC systems based on slow heating and cooling rates 100 7.1.1 Thickness of TGO and length of cracks 108 7.1.2 Raman analyses 112 7.1.3 Oxidation model of the TBC systems 116 7.2 Effect of Al content in the metallic coating 118 8 Complementary discussion 121 8.1 Effect of temperature on the oxidation behavior 121 8.2 Effect of deposition technique for metallic coating on the oxidation behavior 122 8.3 Effect of deposition technique for ceramic coating on the oxidation behavior 122 9 Summary and conclusion 124 10 References 128 / Conventional thermal barrier coating (TBC) systems consist of yttria-stabilized zirconia (YSZ) top coat (TC) on a MCrAlY bond coat (BC), where “M” stands for Co, Ni or CoNi. During their service under a combined heat and oxygen load, a reaction zone forms in the BC/TC interface. This reaction zone consists of thermally grown transition metal oxides (TGO). In the present thesis work, a phenomena related to the TGO formation is introduced. Co32Ni21Cr8Al0.5Y BC was overlaid by atmospheric plasma spraying (APS) technique on Inconel 600 substrates. Thin Al layers were deposited subsequently by DC-Magnetron sputtering on top. Finally, YSZ TC was sprayed by APS technique on the Al layers. The TBC systems were subjected to different thermal treatment procedures in order to investigate the thermo-chemical transformation behaviour of the Al-interlayer. The lifetime of the coatings was investigated under thermal cycling loading with dwell time. The altered TBC systems with Al interlayers (Al-TBC) were compared with the reference TBC systems without Al interlayers (R-TBC). The results show, that the addition of Al layers in the BC/TC interfaces is useful to form a continuous α-Al2O3 layer during the preliminary stage of heat treatment. The in-situ formed dense α-Al2O3 layer obviously acts as a diffusion barrier for oxygen during lifetime test. This has the potential to reduce the formation rate of detrimental oxides. This approach is beneficial to prolong the steady-state growth stage of the TGO, hence allows a higher lifetime for the Al-TBC systems in comparison to the R-TBC systems for the applied thermal loads.:Table of contents 1 Introduction 1 2 Motivation and overall interest 3 3 State of science and technology 5 3.1 Thermal barrier coating (TBC) systems 5 3.1.1 Substrate material 6 3.1.2 Ceramic top coating 6 3.1.3 Metallic bond coating 8 3.1.4 Thermally grown oxides (TGO) 12 3.1.5 Approaches on controlled TGO formation 15 3.1.6 Failure modes of TBC systems 17 3.2 Thermal spray technology 20 3.2.1 Atmospheric plasma spray (APS) technique 20 3.2.2 Formation sequence of the coating 21 3.2.3 Structure of the coating 22 3.3 Technology of thin layer deposition 23 3.4 Conclusions from the state of science and technology 24 4 Scientific objectives and work program 26 5 Experimental procedure 30 5.2 Material selection 30 5.3 Feedstock materials and thermal spray powders 32 5.4 Process selection 33 5.5 Specification of the scientific instruments 33 5.6 Detailed experimental procedure 34 5.6.1 Characterization of thermal spray powders 34 5.6.2 Preparation and characterization of overlaid coatings 35 5.6.3 Thermal treatment of TBC systems 39 5.6.4 Characterization of heat treated coating systems 40 5.6.5 Evaluation of TGO thickness and crack propagation 41 6 Results and discussions 43 6.1 Thermal spray powders and as sprayed coatings 43 6.1.1 Thermal spray powders 43 6.1.1.1 CoNiCrAlY thermal spray powder 43 6.1.1.2 ZrO2 – 8 %Y2O3 thermal spray powders 47 6.1.2 As-sputtered Al layer 50 6.1.2.1 Microstructure features 50 6.1.2.2 Elemental and phase composition analyses 50 6.1.3 As-sprayed coating systems 51 6.1.3.1 Bare and Al-covered CoNiCrAlY coatings 51 6.1.3.2 As-sprayed TBC systems 55 6.2 TBC systems after thermal treatment with different spans of dwell time 58 6.2.1 Thermal treatment with 5 and 30 min dwell time 58 6.2.2 Thermal treatment with 60 and 120 min dwell time 67 6.3 Lifetime test of TBC systems 68 6.3.1 Features in the cross section microstructure 68 6.3.2 Phase composition analyses 71 6.3.3 Elemental and Raman analyses 72 6.3.4 Features in the BC/TC of TBC systems after 80 thermal cycles 87 6.4 Thickness of TGO in the TBC systems 89 6.5 Length of cracks in the TC of the TBC systems 91 6.6 Relation between thickness of TGO and length of cracks 93 6.7 Discussion of loading condition and failure mode 95 6.8 Lifetime prediction of the TBC systems 97 6.9 Oxidation model of the TBC systems 98 7 Complementary work with discussion 100 7.1 Oxidation behavior of the TBC systems based on slow heating and cooling rates 100 7.1.1 Thickness of TGO and length of cracks 108 7.1.2 Raman analyses 112 7.1.3 Oxidation model of the TBC systems 116 7.2 Effect of Al content in the metallic coating 118 8 Complementary discussion 121 8.1 Effect of temperature on the oxidation behavior 121 8.2 Effect of deposition technique for metallic coating on the oxidation behavior 122 8.3 Effect of deposition technique for ceramic coating on the oxidation behavior 122 9 Summary and conclusion 124 10 References 128
65

Inomhusodling av microgreens i urban miljö - ur ett företags- och hållbarhetsperspektiv

Andersson, Josefina, Holmén, Wilma January 2023 (has links)
Syftet med detta arbete var att undersöka inomhusodlingen av microgreens ur ett hållbarhetsperspektiv med anledning av att matförsörjningen står inför stora utmaningar. Detta gjordes i förhållande till resursanvändning, ekonomisk hållbarhet ur ett företagsperspektiv samt till vilka möjligheter och hinder microgreensodlingar har för att öka tillgången på lokala råvaror. Microgreens är unga hjärtbladsväxter som skördas när de har fått sitt första bladpar. I den här studien har både kvantitativa och kvalitativa metoder använts.Metoderna har inkluderat en materialflödesanalys samt en ekonomisk analys som har baseratspå Botildenborgs microgreensodling. Dessutom har semi-strukturerade intervjuer genomförts med två personer som har god kunskap om microgreens. Resultatet visade att resurserna iBotildenborgs microgreensodling används förhållandevis ekologiskt hållbart. Det finns däremot förbättringspotential, såsom ett konstant belysningsintervall och en lägreljusintensitet på LED-lamporna. Samtliga inköpta fröer borde även vara svenskproducerade.Vi kom även fram till att det är ekonomiskt hållbart för Botildenborg att bedriva sin micorgreensodling, även när elpriserna anses vara höga. Här finns också förbättringspotential rörande belysningsintervallet och lampornas ljusintensitet. Vi har konstaterat att de möjligheter som finns för att öka kundernas tillgång på lokala råvaror, såsom microgreens är: utbildning, tillgång året om, ökad efterfrågan samt microgreens närings-, hälso- ochmiljöfördelar. Hindren utgörs däremot av: bristande kunskap hos konsumenterna, greenwashing samt ett högt försäljningspris. Avslutningsvis kan inomhusodlingen av microgreens vara ett steg på vägen till att en tryggad livsmedelsförsörjning uppnås, men inte ett avgörande sådant. / The aim of this study was to investigate indoor farming of microgreens from a sustainability perspective, which is relevant as the food supply is facing major challenges. This was done in relation to resource usage, economic sustainability from a business perspective and which opportunities and obstacles there are for the cultivation of microgreens to increase the access to locally grown food. Microgreens are young cotyledons that are harvested at the true leaf stage. In this study both qualitative and quantitative methods have been used. This has included a material flow analysis and an economic analysis for Botildenborgs indoor farming of microgreens. Further on, semi-structured interviews were carried out with two people with good knowledge of microgreens. The results showed that resources in Botildenborgs indoor farming of microgreens were used relatively efficiently according to ecological sustainability. Although, there is some potential for improvements with constant lighting with low intensity LED lamps. All purchased seeds should also be produced at local scale (in Sweden) as far as possible. We also concluded that it is economically sustainable for Botildenborg to operate their indoor farm, even when the electricity prices are considered high. There is potential forimprovements here too, regarding the continuous lighting and the lamps intensity. We also concluded that opportunities to increase the customers access to locally grown food include education, all year-round access, increased demand, and nutritional, health-related, and environmental benefits. The obstacles on the other hand are lack of knowledge among consumers, greenwashing, and high selling prices. Finally, indoor farming of microgreens can be a step towards food security, but not a decisive one.
66

Staré Brno - MĚSTO MÍSTO TOVÁRNY / Old Brno - CITY INSTEAD OF FACTORY

Bartoš, Marek January 2010 (has links)
Annotation Old Brno - City instead of factory The project deals with partially and untimely used area in Brno - city district Old Brno. The main goal of the project is to offer a valuable alternateve to living in the central part of the city. Raise Brno image of modern developing city. Raise Brno image of great place to live and prevent non-conceptual growing of the city to periphery. The new design creates compact city part with commercial areas and shopping arcades. The new city part will get an appearance of an historically grown city. Building tradition of compact city urban structures lasts for many centuries not only in czech cities.
67

Synchrotron X-Ray Diffraction and Piezospectroscopy used for the Investigation of Individual Mechanical Effects from Environmental Contaminants and Oxide Layer Undulations in Thermal Barrier Coatings

Siddiqui, Sanna 01 January 2014 (has links)
The durability of Thermal Barrier Coatings (TBCs) used on the turbine blades of aircraft and power generation engines has been known to be affected by sand particle ingression comprised of Calcium-Magnesium-Alumina-Silicate (CMAS). Previous studies have shown that these effects present themselves through variations in the thermomechanical and thermochemical properties of the coating. This study investigated the impact of CMAS ingression on the Yttria Stabilized Zirconia Topcoat (YSZ) and Thermally Grown Oxide (TGO) strain in sprayed Thermal Barrier Coating (TBC) samples of varying porosity with and without CMAS ingression. In-Situ Synchrotron X-ray Diffraction measurements were taken on the sample under thermal loading conditions from which the YSZ and TGO peaks were identified and biaxial strain calculations were determined at high temperature. Quantitative strain results are presented for the YSZ and TGO during a thermal cycle. In-plane strain results for YSZ near the TGO interface for a complete thermal cycle are presented, for a 6% porous superdense sample with CMAS infiltration. The outcomes from this study can be used to understand the role of CMAS on the strain tolerance of the TBC coating. It is well known that under engine operational conditions the development of the TGO layer, with large critical stresses, has been linked to failure of the coating. The growth of the TGO manifests as undulations in a series of peaks and troughs. Understanding the mechanics of the oxide layer at these locations provides significant information with respect to the failure mechanisms of the TBC coating. This study investigated the stress at the peak and trough of a TGO undulation for a cycled Dense Vertically Cracked (DVC) plasma sprayed TBC sample through photo-luminescence (PL) spectroscopy. High resolution nanoscale stress maps were taken nondestructively in the undulation of the TGO. Preliminary results from first line mapping of TGO peak and trough scan, at a resolution of 200 nm, have shown a non-uniform TGO stress variation. The results obtained from this study can be used to understand the stress variation in the peak and trough of a DVC sample's TGO undulation and how it contributes to the life of the TBC coating.
68

Mycorrhizal Symbiosis in Forest-Grown American Ginseng (Panax quinquefolius), and the Effect of Mycorrhizal Colonization on Root Ginsenoside Concentrations

Filyaw, Tanner R. 19 September 2017 (has links)
No description available.
69

[pt] A INFLUÊNCIA DOS DEFEITOS CRISTALINOS NA EFICIÊNCIA DE CÉLULAS SOLARES DE BANDA INTERMEDIÁRIA BASEADAS EM SEMICONDUTORES III-V / [en] THE ROLE OF DEFECTS ON THE EFFICIENCY OF INTERMEDIATE BAND SOLAR CELLS BASED ON III-V SEMICONDUCTORS

LIDA JANETH COLLAZOS PAZ 09 February 2021 (has links)
[pt] Neste trabalho tem sido investigado a presença de defeitos em células solares de banda intermediária (IB) de GaAs con pontos quânticos (PQs) de InAs. As três células estudadas contêm camadas de separação entre as camadas de PQs, as quais foram crescidas à diferentes temperaturas, e camadas delgadas de recobrimento dos PQs de diferentes espessuras. As eficiências de conversão de energia destas células foram medidas previamente, sendo que a célula com camadas de separação crescidas à 700 graus C e com camadas de recobrimento de 3 nm é a mais eficiente (6.9 por cento). As outras duas células com camadas de recobrimento de 6 nm apresentam menores eficiências: uma, com camadas separadoras crescidas à 700 graus C, com 5.1 por cento, e a outra, com camadas separadoras crescidas à 630 graus C, com 2.8 por cento. Estudos de DLTS e Laplace DLTS mostram que há um grande número de defeitos em altas concentrações na célula menos eficiente, enquanto nas outras duas células só é detetado o mesmo defeito EL2 em menores concentrações. Portanto, a redução dos defeitos induz o incremento da eficiência das células IB. Amostras adicionais foram crescidas e estudadas pelas mesmas técnicas, entre elas, três células solares com estruturas idênticas às das células IB, mas sem PQs, e quatro amostras GaAs mono-camada dopadas com carbono e silício, similares às camadas de contacto p e n das células IB. Do estudo das três células sem PQs foi possível determinar que alguns defeitos nas células IB são induzidos pelas condições de crescimento dos PQs ou são induzidos pela temperatura de crescimento das camadas separadoras. O estudo das amostras mono-camada indicou a presença de defeitos nos contatos p e n que podem armadilhar os portadores foto-excitados nas células sob operação e, portanto, limitar a eficiência delas. Os resultados deste trabalho contribuem para desenvolver novas estratégias para crescimento epitaxial de células IB no laboratório LabSem na PUC-Rio. / [en] Defects present in structures of intermediate band (IB) solar cells of GaAs with InAs quantum dots (QDs) grown by MOVPE have been investigated. The three studied IB solar cells differ in the growth temperature of the spacer layers that separate the InAs QD layers in the active region and the thickness of the thin layer that capping each QD layer. Previously, the energy conversion efficiencies of these cells were measured and the cell with the highest spacer layer-growth temperature (700 C degrees) and thinner capping layer (3 nm) showed the highest efficiency, about 6.9 percent. The cells with thicker capping layers (6 nm) showed lower efficiencies, one of them, with spacer layers grown at 700 C degrees, reaching 5.1 percent, and the other one, with spacer layers grown at 600 C degrees, reaching only 2.8 percent. In this work, DLTS and Laplace DLTS studies show that the cell with the lowest efficiency has the largest number and highest concentrations of defects, unlike the other two cells, which have only one trap, EL2, in lower concentrations. These results demonstrate that the different growth conditions are determinant for the formation of defects and that the defect reduction leads to the increase of the IB solar cell efficiencies. Other samples were also grown and studied by the same techniques: three solar cells with identical structure as the IB solar cells, but without QDs, and individually doped GaAs samples that represent the p and n contact sides of the IB solar cells. From the study of the cells without QDs, the origin of some defects in the IB solar cells was found to be related to the QD growth conditions or related to the spacer layer-growth temperature. The study of the GaAs samples indicated the presence of defects in the p and n sides that could trap photo-excited carriers collected through these contacts during cell operation and thus reduce the efficiency. The results of this work allow developing new strategies to improve the epitaxial growth quality of IB solar cells in the laboratory of semiconductors LabSem of PUC-Rio where the studied samples were grown.
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Curvas padrão pôndero-estatural de portadores de Síndrome de Down procedentes da região urbana da cidade de São Paulo / Growth charts (standard grown curves) of children with down Syndrome deriving from São Paulo\'s Urban area

Mustacchi, Zan 29 November 2002 (has links)
De fato, por não existir um levantamento antropométrico de crianças com síndrome de Down no Brasil, foi realizado em São Paulo um estudo biométrico prospectivo que permitiu a elaboração de curvas antropométricas avaliando taxas de peso, estatura e perímetro cefálico elaboradas por tabelas e gráficos com valores lapidados de 4 percentis de dois grupos etários de ambos os sexos divididos de 0-24 meses e de 2-8 anos respectivamente.o estudo considerou e excluiu, quando pertinente, fatores ambientais ou genéticos paralelos que eventualmente pudessem interferir nas variáveis avaliadas. A ampla revisão bibliográfica e a comparação dos dados antropométricos permitiram enfatizar a importância de curvas padrões nacionais para estatura, peso e perímetro cefálico de crianças com síndrome de Down, facilitando o diagnóstico diferencial entre outros comprometimentos clínicos, auxiliando na intervenção clínico-Iaboratorial, na prevenção e acompanhamento médico. / Considerint that there is any anthropometrical evaluation in children with Down\'s syndrome in Brazil, the objective of this prospective biometric investigation was to construct anthropometrical curves for weight, stature and cephalic perimeter in children with Down\' s syndrome living in São Paulo urban area. Ali measurements were obtained from January 1980 to December 1999. Ali height or cephalic perimeter values 10% below or above and weight values 16% below or above of the 1st and 3rd quartile were excluded. Tables for each sex during 0-24 months and 2-8 years were presented in mean, standard deviations, percentiles and quartiles and graphics were presented in percitiles. Environmental and genetic factors associated that could interfere in development were identified and the proband excluded from the sample. The employing of a national pattem curve of stature, weight and cephalic perimeter for individuaIs with Down\' s syndrome would be useful in differential diagnosis among other clinical disorders associated to this genetic malformation providing better clinical intervention and prevention of comorbidity.

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