963 resultados para 750 Painting
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One major aspect of the poverty status in Nigeria is the high rate of unemployment with the attendant economic in capacity, which in turn is responsible for the persistent problem of malnutrition over the decades. This paper is focused on how women can be empowered for better productivity in fish culture enterprises, seeing that women have been active in different aspects of agricultural production. They also sustain more than half of the developing countries such as Nigeria. Some problems being encountered by would be women fish farmers and suggestions on how women participation in fish and shellfish culture enterprises can be enhanced are proffered. The major ones being those sustainable policies by the Government State ADPs and NGOs are applied to ensure adequate motivation of women for fish culture enterprises
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An acoustic-optics programmable dispersive filter (AOPDF) was first employed to actively control the linearly polarized femtosecond pump pulse frequency chirp for supercontinuum (SC) generation in a high birefringence photonic crystal fiber (PCF). By accurately controlling the second order phase distortion and polarization direction of incident pulses, the output SC spectrum can be tuned to various spectral energy distributions and bandwidths. The pump pulse energy and bandwidth are preserved in our experiment. It is found that SC with broader bandwidth can be generated with positive chirped pump pulses except when the chirp value is larger than the optimal value, and the same optimal value exists for the pump pulses polarized along the two principal axes. With optimal positive chirp, more than 78% of the pump energy can be transferred to below 750 nm. Otherwise, negative chirp will weaken the blue-shift broadening and the SC bandwidth. (C) 2007 Elsevier B.V. All rights reserved.
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The nature of the subducted lithospheric slab is investigated seismologically by tomographic inversions of ISC residual travel times. The slab, in which nearly all deep earthquakes occur, is fast in the seismic images because it is much cooler than the ambient mantle. High resolution three-dimensional P and S wave models in the NW Pacific are obtained using regional data, while inversion for the SW Pacific slabs includes teleseismic arrivals. Resolution and noise estimations show the models are generally well-resolved.
The slab anomalies in these models, as inferred from the seismicity, are generally coherent in the upper mantle and become contorted and decrease in amplitude with depth. Fast slabs are surrounded by slow regions shallower than 350 km depth. Slab fingering, including segmentation and spreading, is indicated near the bottom of the upper mantle. The fast anomalies associated with the Japan, Izu-Bonin, Mariana and Kermadec subduction zones tend to flatten to sub-horizontal at depth, while downward spreading may occur under parts of the Mariana and Kuril arcs. The Tonga slab appears to end around 550 km depth, but is underlain by a fast band at 750-1000 km depths.
The NW Pacific model combined with the Clayton-Comer mantle model predicts many observed residual sphere patterns. The predictions indicate that the near-source anomalies affect the residual spheres less than the teleseismic contributions. The teleseismic contributions may be removed either by using a mantle model, or using teleseismic station averages of residuals from only regional events. The slab-like fast bands in the corrected residual spheres are are consistent with seismicity trends under the Mariana Tzu-Bonin and Japan trenches, but are inconsistent for the Kuril events.
The comparison of the tomographic models with earthquake focal mechanisms shows that deep compression axes and fast velocity slab anomalies are in consistent alignment, even when the slab is contorted or flattened. Abnormal stress patterns are seen at major junctions of the arcs. The depth boundary between tension and compression in the central parts of these arcs appears to depend on the dip and topology of the slab.
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We studied the single-shot damage in magnesium fluoride irradiated by 800 nm femtosecond (fs) laser. The dependence of damage thresholds on the laser pulse durations from 60 to 750 fs was measured. The pump-probe measurements were carried out to investigate the time-resolved electronic excitation processes. A coupled dynamic model was applied to study the microprocesses in the interaction between fs laser and magnesium fluoride. The results indicate that both multiphoton ionization and avalanche ionization play important roles in the femtosecond laser-induced damage in MgF2. (C) 2006 Elsevier Ltd. All rights reserved.
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Interleukin 2 (IL2) is the primary growth hormone used by mature T cells and this lymphokine plays an important role in the magnification of cell-mediated immune responses. Under normal circumstances its expression is limited to antigen-activated type 1 helper T cells (TH1) and the ability to transcribe this gene is often regarded as evidence for commitment to this developmental lineage. There is, however, abundant evidence than many non-TH1 T cells, under appropriate conditions, possess the ability to express this gene. Of paramount interest in the study of T-cell development is the mechanisms by which differentiating thymocytes are endowed with particular combinations of cell surface proteins and response repertoires. For example, why do most helper T cells express the CD4 differentiation antigen?
As a first step in understanding these developmental processes the gene encoding IL2 was isolated from a mouse genomic library by probing with a conspecific IL2 cDNA. The sequence of the 5' flanking region from + 1 to -2800 was determined and compared to the previously reported human sequence. Extensive identity exists between +1 and -580 (86%) and sites previously shown to be crucial for the proper expression of the human gene are well conserved in both sequence location in the mouse counterpart.
Transient expression assays were used to evaluate the contribution of various genomic sequences to high-level gene expression mediated by a cloned IL2 promoter fragment. Differing lengths of 5' flanking DNA, all terminating in the 5' untranslated region, were linked to a reporter gene, bacterial chloramphenicol acetyltransferase (CAT) and enzyme activity was measured after introduction into IL2-producing cell lines. No CAT was ever detected without stimulation of the recipient cells. A cloned promoter fragment containing only 321 bp of upstream DNA was expressed well in both Jurkat and EL4.El cells. Addition of intragenic or downstream DNA to these 5' IL2-CAT constructs showed that no obvious regulatory regions resided there. However, increasing the extent of 5' DNA from -321 to -2800 revealed several positive and negative regulatory elements. One negative region that was well characterized resided between -750 and -1000 and consisted almost exclusively of alternating purine and pyrimidines. There is no sequence resembling this in the human gene now, but there is evidence that there may have once been.
No region, when deleted, could relax either the stringent induction-dependence on cell-type specificity displayed by this promoter. Reagents that modulated endogenous IL2 expression, such as cAMP, cyclosporin A, and IL1, affected expression of the 5' IL2-CAT constructs also. For a given reagent, expression from all expressible constructs was suppressed or enhanced to the same extent. This suggests that these modulators affect IL2 expression through perturbation of a central inductive signal rather than by summation of the effects of discrete, independently regulated, negative and positive transcription factors.
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The original method, proposed by Yentsch (1957), of determination of chlorophyll directly in the cells, attracts attention by its simplicity. In order to measure the content of chlorophyll by this method, a determined volume of suspension of algae is filtered through a membrane filter. The latter is dried a little, clarified by immersion oil, clamped between two glasses, and spectrophotometrized. Extinction is read off at , wavelengths equal to 670 millimicrons (around the maximum absorption of chlorophyll a in the cell) and 750 millimicrons (correction for non- specific absorption and dispersion of light by particles of the preparation). The method of Yentsch was employed by the authors for determination of chlorophyll-a in samples of phytoplankton. They conclude that in spite of the simplicity and convenience of determination the method must be applied sufficiently carefully. It is more suitable for analysis of cultures of algae, where, non-specific absorption of light is insignificant.
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O objetivo deste estudo foi comparar in vitro o desgaste dental de pré-molares (PM) e molares (M) e sua relação com o valor de dureza Vickers dos materiais utilizados como antagonistas em uma máquina de abrasão simulada para provocar o desgaste nos dentes testados. Os materiais antagonistas utilizados foram VeraBond II (liga de Ni-Cr), Solidex (resina composta) e IPS Empress 2 (cerâmica). Para cada ensaio de dureza, foram preparados seis corpos-de-prova de cada material, os quais foram polidos sob refrigeração, com ciclo de 20 min para cada granulação. Num microdurômetro (HMV-2), foram realizadas três mossas por quadrante, cada uma sob carga de 19,614 N por 30 s, totalizando 12 mossas de base quadrada com ângulo de 136 entre os planos. O teste de abrasão foi realizado numa máquina simuladora de abrasão, freqüência de 265 ciclos/min e 4,4 Hz, com um percurso do antagonista de 10 mm à velocidade de 88 mm/s. Cada dente foi testado em oposição a um antagonista (foram 6 pares dente/material para cada grupo), em água deionizada, sob carga de 5 N, por 150 min, num total de 39.750 ciclos. Foram utilizados dezenove dentes 1 pré-molares, dezenove 3 molares e confeccionados doze antagonistas em cada material em forma de pastilha. Cada grupo de seis dentes foi testado em oposição a seis antagonistas do mesmo material. Ademais, um dente 1 pré-molar (PM) e um dente 3 molar (M) foram testados em oposição ao Plexiglass. Com relação ao desgaste do esmalte dentário (PM+M) segundo o material antagonista, o teste de Kruskal-Wallis evidenciou diferença significativa com p-valor < 0,001 e o teste de Mann-Whitney evidenciou diferença significativa nas comparações PM+M/resina X PM+M/metal (p-valor < 0,001), PM+M/resina X PM+M/cerâmica (p-valor < 0,001) e PM+M/metal X PM+M/cerâmica (p-valor = 0,002). A análise isolada, considerando pré-molares e molares separadamente, encontrou diferença significativa em relação ao desgaste do esmalte dentário no teste de Kruskall-Wallis, porém não detectou diferença significativa no teste de comparação múltipla Mann-Whitney quando comparou o desgaste sofrido pelo PM/metal em relação ao PM/cerâmica. Em relação à dureza Vickers detectou-se diferença significativa da dureza dos materiais no teste de Kruskall-Wallis (p-valor < 0,001) e também no teste de Mann-Whitney nas comparações múltiplas com p-valor = 0,002. Comparando-se a dureza com a perfilometria, observou-se uma correlação estatisticamente significativa (p ≤ 0,05) na correlação negativa (ρ= -0,829) entre a dureza do metal como material antagonista e o desgaste do esmalte dentário do dente molar. Os resultados sugeriram que todo material restaurador indireto estudado causou desgaste ao esmalte dentário quando submetido a forças de simulação de abrasão com carga. Embora tenha sido observada correlação entre dureza e resistência à abrasão, essa correlação foi pouco significativa.
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The reaction γ + p p + π+ + π- has been studied for photon energies between 800 and 1500 MeV and for dipion masses between 510 and 900 MeV. The bremsstrahlung beam from the Caltech synchrotron was passed through a liquid hydrogen target and spark chambers were used to detect the three final particles. In addition, the proton energy was determined by a range measurement. Approximately 40,000 photographs were taken, yielding 3018 acceptable events. The results were fit to an incoherent combination of the N*(1238) resonance, the po (750) resonance, and three-body phase space, with various models being tried for po production. The total cross section for po production is consistent with previous experiments. However, the angular dependence of the cross section is slightly more peaked in the forward direction, and the ratio of po production to phase space production is larger than previously observed.
However, since this experiment was only sensitive to the production angles cos θ cm ≥ .75, statistical fluctuations and/or an anisotropic distribution of background production have a severe influence on the po to background ratio. Of the po models tested, the results prefer po production by the one pion exchange mechanism with a very steep form factor dependence. The values of the mass and width of the po found here are consistent with previous experiments.
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Gaur egun, Botere Judizialaren Lege Organikoaren Erreformatik abiatuta -abenduaren 23ko 19/2003 LOren bidez gauzatua-, hainbat erregelamendu eta araudi sortu dira hizkuntza-normalizaziorako prozesu garrantzitsu bat abiarazteko Justizia Administrazioan. Beraz, aipatzekoa da orain arte eginiko ahalegina ez dela nolanahikoa izan, emaitzak desberdinak izan badira ere hainbat gorabehera medio, eta bereziki nabarmentzekoa da Justizia Administrazioaren zerbitzura diharduten pertsonen konpromisoa euskalduntze-prozesuan eta hizkuntzaren erabilera bultzatzeko ekimenetan. Botere Judizialaren Lege Organikoak irismen juridiko handia du zuzenbide publikoaren esparruen multzoan. Hori horrela, eragina du Konstituzio Zuzenbidean -Estatuaren funtsezko Botere bati eta Botere Judizialaren Kontseilu Nagusia bezalako organo konstituzional bati eragiten dien aldetik-, Zuzenbide Prozesalean -Epaitegien eta Auzitegien antolakuntza eta funtzionamendua erregulatzen duen aldetik- eta baita Administrazio Zuzenbidean ere -erlazio juridiko administratiboak eta administrazio-izaerako prozedurak barne hartzen dituen neurrian, adibidez, Epaileen eta Magistratuen estatutu-araubideari dagozkionak-. Beste ikuspegi batetik, Botere Judizialaren Lege Organikoa erreferentzia da epaileriaren estatutu juridikoan, «Zuzenbide Judiziala» izenez ere ezaguna, hiru eratako funtsezko alderdiak barne hartzen dituena: alderdi subjektiboak -Botere Judizialaren organoak eta Epaileen eta Magistratuen estatutu-araubidea, baita Idazkari Judizialen eta Justizia Administrazioaren zerbitzura diharduten gainerako funtzionario Kidegoen estatutu-araubidea ere-; alderdi objektiboak -Botere Judizialaren gobernua, Jurisdikzioaren hedadura eta mugak, eta Epaileen eta Magistratuen independentzia-; eta azkenik, alderdi formalak -Organo jurisdikzionalen araubide prozesala, ekinbide judizialen iraupena eta forma, eta hainbat gairi dagozkien prozedurak: hautaketa, lanpostuak betetzea, egoera administratiboak, ikuskaritza eta Karrera Judizialeko kideen diziplinaaraubidea eta ikuskapena-. Botere Judizialaren Lege Organikoaren —dokumentu berez luzea -eta haren ondoz ondoko erreformen itzulpenarekin, UPV/EHUko zuzenbideko irakasle-talde baten lan serio eta zorrotza bururatzen da. Lan horretan, itzulpenean espezializatutako hizkuntzalarien laguntza izan dute, itzulpen fidel eta teknikoena egiteko, termino egokienak hautatu eta erabilita.
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Tesis con Mención de Doctor Internacional
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以硅酸四乙酯(TEOS)和甲基三乙氧基硅烷(MTEOS)为前驱材料,用溶胶-凝胶(sol-gel)方法在钛宝石表面制备得到均匀性良好且具有高激光损伤阈值的有机硅复合凝胶增透膜。膜层在钛宝石激光器输出波段(750~850nm)的增透效果显著,其平均透过率超过98.6%;激光破坏阈值为2.2J/cm^2(800nm,300ps);膜层表面均匀性达到激光波面的要求,在皮秒、飞秒超短脉冲高功率激光领域具有应用价值。溶胶的性能测试结果表明,溶胶粘度和成膜折射率均随溶液中CH3SiO1.5溶胶体含量的增加而增大,而膜
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Porous SiO2 antireflective (AR) coatings are prepared from the colloidal silica solution modified with methyltriethoxysilane (MTES) based on the sol-gel route. The viscosity of modified silica suspensions changes but their stability keeps when MTES is introduced. The refractive indices of modified coatings vary little after bake treatment from 100 to 150 Celsius. The modified silica coatings on Ti:sapphire crystal, owning good homogeneity, display prominent antireflective effect within the laser output waveband (750-850 nm) of Ti:sapphire lasers, with average transmission above 98.6%, and own laser induced damage thresholds (LIDTs) of more than 2.2 J/cm2 at 800 nm with the pulse duration of 300 ps.
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A presente pesquisa trata da formação da teoria da pintura durante o período das Seis Dinastias, que ocupa o período que vai do ano 229 ao ano 589 da era presente. São discutidos quatro teóricos principais: Gu Kaizhi, Zong Bing, Wang Wei e Xie He. Além disto, apresentamos uma tradução diretamente do chinês para os textos de cada um dos autores analisados. No decorrer de nossa análise tentaremos demonstrar os elos de continuidade existentes entre os diversos teóricos, baseando-nos nas evidências textuais. Além disto, enfatizaremos o fato de ser este o período em que se forma a teoria da pintura chinesa. O período inicial da história dessa teoria é o tema desta pesquisa
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Essa dissertação é uma proposta de releitura do conjunto de murais no interior da Capela de Chapingo, México. Tal releitura de crítica artística relaciona-se à apropriação de uma metodologia derivada da própria noção de capela, metodologia essa que compactua com o ambiente artístico em questão e com a fenomenologia do contemplador desse conjunto. O objetivo dessa proposta é apresentar as nuances envolvidas no conceito-chave, por parte da historiografia artístico-religiosa, de suporte-capela, isto é, a capela não apenas como ambiente religioso, mas como ocasião artística