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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.
81

Inventário da araneofauna (Arachnida, Araneae) do Parque Nacional de Sete Cidades, Piauí, Brasil

CARVALHO, Leonardo Sousa 25 March 2008 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-09-17T16:44:12Z No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InventarioAraneofaunaArachnida.pdf: 1467992 bytes, checksum: 2351c92a46d3e972a9714cbaa63b9f08 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-09-27T16:57:46Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InventarioAraneofaunaArachnida.pdf: 1467992 bytes, checksum: 2351c92a46d3e972a9714cbaa63b9f08 (MD5) / Made available in DSpace on 2013-09-27T16:57:46Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InventarioAraneofaunaArachnida.pdf: 1467992 bytes, checksum: 2351c92a46d3e972a9714cbaa63b9f08 (MD5) Previous issue date: 2008 / Foi realizado o inventário da araneofauna do Parque Nacional de Sete Cidades (municípios de Brasileira e Piracuruca, Piauí), utilizando amostragem padronizada para permitir comparações entre as assembléias de aranhas de seis fitofisionomias existentes na área de estudo e obter estimativas de riqueza. Utilizaram-se dados oriundos amostragem com armadilhas de queda (PTF), extratores de Winkler (WIN), guarda-chuva entomológico (GCE), rede de varredura (RV) e coletas manuais noturnas (MN), totalizando 1386 amostras; além do exame de todos os demais espécimes já coletados na área de estudo (n=1166). As análises estatísticas foram realizadas utilizando-se os dados obtidos com GCE, RV e MN. Ao todo, foram coletados 14.890 indivíduos (4491 adultos), segregados em 364 espécies. Destas, 72 foram determinadas a nível específico, 62 são novos registros para a área de estudo, 2 são novos registros para o Brasil e 48 foram reconhecidas como espécies novas por especialistas. A aplicação dos métodos GCE, RV e MN resultou em 11.085 aranhas, pertencentes a 303 espécies. As estimativas de riqueza variaram entre 355 (Bootstrap) e 467 (Jack 2). Entretanto o estimador que apresentou maior tendência a atingir a assíntota foi Chao 2 (403 spp.). A riqueza observada foi maior na mata seca semi-decídua (131 spp.), seguida pela mata de galeria (104 spp.), campo limpo (102 spp.), cerradão (91 spp.), cerrado típico (88 spp.) e cerrado rupestre (78 spp.). A eficiência dos métodos de coleta exibiu variação de acordo com a fitofisionomia onde o método foi aplicado, destacando-se a elevada eficiência da rede de varredura em áreas abertas. A composição de espécies variou entre as fitofisionomias e pode ser, em parte, explicada pela complexidade estrutural das áreas em questão. Os resultados das análises de agrupamento sugerem que em condições de dominância elevada, estes testes sejam realizados com coeficientes que utilizem dados qualitativos, a fim de anular-se o efeito da escolha do coeficiente e/ou a necessidade de transformação dos dados. De maneira geral, a araneofauna do Parque Nacional de Sete Cidades não segue padrões de agrupamento como sugerido para as análises botânicas, em que fitofisionomias campestre, savânicas e florestais são agrupadas. / An inventory of the spider fauna of Sete Cidades National Park (Brasileira and Piracurua municipalities, State of Piauí), is presented using standardized sampling procedures to allow comparisons between the spider assemblages of six phytophysiognomies present at the study site and to obtain richness estimates. Data from sampling with pit-fall traps (PTF), Winkler apparatus (WIN), beating tray (GCE), sweeping net (RV) and nocturnal manual colleting (MN), totalizing 1386 samples were analyzed, together with all other specimens previously collected at the study site (n=1166). The statistical analyses were performed using data obtained with GCE, RV and MN. Altogether, 14.890 individuals (4491 adults), belonging to 364 species, were collected. From these, 72 were determined at specific level, 62 are new records for the study site, 2 are new records for Brazil and 48 were recognized as new species by specialists. The application of the methods GCE, RV and MN resulted in 11.085 spiders, belonging to 303 species. The richness estimates varied between 355 (Boostrap) and 467 (Jack 2) species. The best fit estimator, which first showed a trend to reach an asymptote, was Chao 2 (403 spp.). The observed richness was greater in tropical semideciduous dry forest (mata seca semi-decídua, 131 spp.), followed by the tropical ombrophilous alluvial occasionally flooded forest (mata de galleria, 104 spp.), medium tall grassland consisting mainly of bunch grasses (campo limpo, 102 spp.), evergreen broad-leaved woodland (cerradão, 91 spp.), evergreen broad-leaved sclerophyllous shrubland (cerrado típico, 88 spp.) and smaller in deciduous subdesert shrubland (cerrado rupestre). The efficiency of the collecting methods exhibited variation according to the phytophysiognomy in which it was applied, especially in the case of the sweeping net, which was much more efficient in open areas. The variation in species composition between the sampled phytophysiognomies can be, in part, explained by differences in the structural complexity of these vegetation types. The results of the cluster analysis suggest that, in conditions of high dominance, these tests should be performed with qualitative coefficients, in order to neutralize the effect of coefficient choose and/or the need of data transformation. The Sete Cidades National Park´s spider fauna does not followed the clustering patterns suggested by botanical analysis, by which grasslands, savannas and forested phytophysiognomies are grouped.
82

Synthesis and Characterization of Rhodium Acetate with Functionalized Benzonitriles

Lowe, Jared M 01 May 2015 (has links)
Dirhodium complexes are effective catalysts in carbene transformations. These reactions involve chemistry between the catalyst and a carbene generated in situ. In order to better understand the rhodium-carbon bond, studies of rhodium acetate, Rh2(OAc)4, and a variety of functionalized benzonitriles were proposed. Diadducts of rhodium acetate with 4-nitrobenzonitrile, 4-aminobenzonitrile, 4-(dimethylamino)benzonitrile, and 3,5-dinitrobenzonitrile were successfully prepared and characterized by X-ray crystallography. IR and NMR spectroscopy were also employed for characterization purposes.
83

Jämförelse av off-the-shelf-hårdvara för realtidsapplikationer / Comparison of off-the-shelf hardware for real-time applications

Engström, Hampus, Ring, Christoffer January 2013 (has links)
Vid implementering av realtidsapplikationer krävs det att man kan använda hårdvaran på ett deterministiskt vis. En realtidsapplikation ställer stora krav på körtider och hur applikationen schemaläggs. Det är därför av största vikt att kontrollera om de uppfyller dessa krav. I detta examensarbete har tre system för realtidsapplikationer jämförts och en analys av framförallt sina beräkningsförmågor och hur pass deterministiskt de uppför sig gällande körtider har gjorts. Även andra aspekter så som utvecklingsmiljöer för mjukvara, tillbehör och effektförbrukning har jämförts.
84

Heavy atom induced phosphorescence of organic materials using mono- and trifunctional organomercury derivatives

Burress, Charlotte Nicole 15 May 2009 (has links)
This dissertation focuses on the phosphorescence of organic chromophores using perfluoro-ortho-phenylene mercury (1) and bis(pentafluorophenyl)mercury (2) as external heavy atom effect inducers. To ascertain the suitability of these luminescent adducts for OLED applications, several research objectives have been investigated. To further shorten the triplet lifetimes of adducts involving 1, a strategy was developed which combines both internal and external heavy atom effects. Specifically, complexes involving 1 and N-methylcarbazole, N-methylindole and the 1- halonaphthalenes were investigated. The existence and stability of the complexes could be confirmed in solution by fluorescence spectroscopy. In the solid state, these adducts form supramolecular binary stacks where the molecules of 1 alternate with the aromatic substrate. As a result of the mercury external heavy atom effect, all of these adducts display intense room temperature phosphorescence of the free arene. With the Nheterocycles, the triplet lifetimes were drastically reduced to below 100 mu-s. To appreciate the origin of the unusual heavy atom effects observed in arene adducts with 1, 2 was studied as a monofunctional analog to 1. By utilizing fluorescence spectroscopy, naphthalene, biphenyl, and fluorene complexes of 1 and 2 have been detected in solution. The solid state structure of the adducts with 2 reveal supramolecular binary stacks. Comparison of the photophysical results supports the occurrence of cooperative effects between the Lewis acidic mercury centers of 1, which make it a more efficient external heavy-atom effect inducer. Polymeric materials which are amenable to deposition in thin layers were investigated as substrates for 1 and 2. Both poly(vinyl-2-naphthalene) and poly(vinylcarbazole) interact with 1 and 2 in solution as evidenced by fluorescence spectroscopy. With the solid blend 1•PVK, a small doping percentage of 1 results in white emission, while larger percentages of 1 yield bright orange emission. This dissertation presents the first structurally characterized ternary complex with 1, carbazole, and coordinating solvents THF and triethylamine. IR spectroscopy and short N···O and N···N distances in the solid state indicates that the acidic N-H moiety of carbazole interacts with the solvent by hydrogen bonding. In the extended structure, molecules of 1 and the hydrogen bonded complex alternate to form supramolecules.
85

A Novel Current Loop for DSP-Based Power Factor Correction Circuits

Chang, Yun-Hsiang 17 July 2007 (has links)
This thesis mainly focuses on active power factor correction (PFC) circuit research. Based on DSP, a circuit with a digital controller is developed. Boost converter is used as the power stage. For power factor correction, the control law is realized with DSP and the control strategy of controller adopts the multi-loop method, i.e. voltage-loop and modified PI current-loop. Finally, compared with the circuit using the conventional PI control law, performances of the modified PI current-loop circuit are obviously optimized.
86

Effects of copper on phosphorus utilization in Ulva fasciata Delile (Ulvales, Chlorophyta)

Huang, Ya-Ling 30 July 2002 (has links)
The effects of copper on growth and phosphorus (P) utilization were investigated in the marine chlorophyte Ulva fasciata Delile. Both the daily specific growth rate and tissue P contents decreased as increasing CuSO4 concentrations, while the contents of total tissue, intracellular and cell-wall Cu increased. Based on the relationship between daily specific growth rate and external CuSO4 concentrations, the upper limit of U. fasciata is 100 uM CuSO4. After 4-day exposure to varying CuSO4 concentrations, Pi uptake was inhibited. Analysis of P fraction in U. fasciata exposed to 100 uM CuSO4 shows that the Cu-induced decline in total tissue P contents is mainly due to a decrease in both soluble reactive P (i.e. Pi). Exposure to 100 uM of Cu caused the accumulation of total tissue Cu contents to a plateau and then rose again at day 3, and tissue P contents and daily specific growth rate decreased at day 4. IC50 (concentration of 50 % inhibition) of daily specific growth rate and tissue P contents are 9.8 and 37.8 uM of Cu concentration in the medium, respectively, and 0.76 and 1.44 mg¡Dg-1 DW for total tissue Cu contents, respectively. Overall, Cu causes Cu accumulation in intracellular space and cell wall and decrease of growth and P contents of U. fasciata partly via Pi uptake inhibition.
87

Androgen Promotes Osteoblast Proliferation through Activation of Phosphatidylinositol-3-OH Kinase /Akt Signaling Pathway

Huang, Kai-Lieh 08 July 2003 (has links)
Androgen has been shown to stimulate proliferation of osteoblast-like MC3T3-E1 cells. However, the molecular mechanism responsible for this effect remains to be elucidated. In the present study we demonstrate herein the non-genomic effect of androgen on osteoblast-like MC3T3-E1 cells involving activation of a PI(3)K/Akt signaling pathway and stimulating proliferation. In studies of steroids signaling, 5a-dihydrotestosterone (DHT), testosterone and 17b-estradiol but not dexamethasone or progesterone induced a rapid and transient phosphorylation of Akt in MC3T3-E1 cells. The androgen-induced Akt activation reached to the climax after 15 min and gradually diminished to baseline after 60 min. This induction of androgen was unaffected by actinomycin D and was specifically blocked by androgen receptor (AR) antagonist hydroxyflutamide (HF) or transfection of siRNA-AR. Treatment of MC3T3-E1 cells with PI(3)K inhibitor LY294002 or transfection with kinase-deficient Akt blocked androgen-induced cells proliferation. Moreover, androgen-induced activation of Akt was abolished by inhibitors of Src kinase, Gi-protein and phospholipase C showing the involvement of these effectors in androgen signaling pathway. Further, androgen-induced activation of Akt was dependent on intracellular calcium as shown by the effect of EGTA and intracellular calcium chelator BAPTA/AM. Fluorescence microscopy showed translocation of phospho-Akt from cytosol into nucleus after androgen treatment but no change in the subcellular distribution of phospho-Akt when HF or LY294002 pretreatment was administered to the cells. These results strongly suggest that phosphorylation of Akt in osteoblast cells is mediated by androgen receptor and the androgen-induced translocation of Akt is an important step in the androgen/AR signaling pathway that mediates osteoblast cells proliferation.
88

Prime ideals in low-dimensional mixed polynomial/power series rings

Eubanks-Turner, Christina. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Sept. 18, 2008). PDF text: v, 109 p. : ill. ; 459 K. UMI publication number: AAT 3303652. Includes bibliographical references. Also available in microfilm and microfiche formats.
89

Streitwagentechnologie in der Ramses-Stadt /

Herold, Anja. Pusch, Edgar B. January 1900 (has links)
Texte révisé de: Diss.--Universität Hambourg, 1993. / Bibliogr. p. 141-148 (vol. 1) et p. [351]-360 (vol. 2).
90

Polynomial identities of Hopf algebras /

Kotchetov, Mikhail V., January 2002 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 127-130.

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