Absorption characteristic and nonvolatile holographic recording in LiNbO3 : Cr : Cu crystals

The absorption characteristic of lithium niobate crystals doped with chromium and copper (Cr and Cu) is investigated. We find that there are two apparent absorption bands for LiNbO3:Cr:Cu crystal doped with 0.14 wt.% Cr2O3 and 0.011 wt.% CuO; one is around 480 nm, and the other is around 660 nm. With a decrease in the doping composition of Cr and an increase in the doping composition of Cu, no apparent absorption band in the shorter wavelength range exists. The higher the doping level of Cr, the larger the absorbance around 660 nm. Although a 633 nm red light is located in the absorption band around 660 nm, the absorption at 633 nm does not help the photorefractive process; i.e., unlike other doubly doped crystals, for example, LiNbO3:Fe:Mn crystal, a nonvolatile holographic recording can be realized by a 633 nm red light as the recording light and a 390 nm UV light as the sensitizing light. For LiNbO3:Cr:Cu crystals, by changing the recording light from a 633 nm red light to a 514 nm green light, sensitizing with a 390 nm UV light and a 488 nm blue light, respectively, a nonvolatile holographic recording can be realized. Doping the appropriate Cr (for example, N-Cr = 2.795 X 10(25)m(-3) and N-Cr/N-Cu = 1) benefits the improvement of holographic recording properties. (c) 2005 Optical Society of America.

The structure specificity of alpha-chymotrypsin. I. Polypeptides as substrates. II. N-acylated peptide esters as substrates. III. Some reactive esters of N-acylated amino acids as substrates

The structural specificity of α-chymotrypsin for polypeptides and denatured proteins has been examined. The primary specificity of the enzyme for these natural substrates is shown to closely correspond to that observed for model substrates. A pattern of secondary specificity is proposed.

A series of N-acetylated peptide esters of varying length have been evaluated as substrates of α-chymotrypsin. The results are interpreted in terms of proposed specificity theories.

The α-chymotrypsin-catalyzed hydrolyses of a number of N-acetylated dipeptide methyl esters were studied. The results are interpreted in terms of the available specificity theories and are compared with results obtained in the study of polypeptide substrates. The importance of non-productive binding in determining the kinetic parameters of these substrates is discussed. A partial model of the locus of the active site which interacts with the R’₁CONH- group of a substrate of the form R’₁CONHCHR₂COR’₃ is proposed.

Finally, some reactive esters of N-acetylated amino acids have been evaluated as substrates of α-chymotrypsin. Their reactivity and stereo-chemical behavior are discussed in terms of the specificity theories available. The importance of a binding interaction between the carboxyl function of the substrate and the enzyme is suggested by the results obtained.

Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume III. Big Cypress National Preserve

Amphibian declines and extinctions have been documented around the world, often in protected natural areas. Concern for this trend has prompted the U.S. Geological Survey and the National Park Service to document all species of amphibians that occur within U.S. National Parks and to search for any signs that amphibians may be declining. This study, an inventory of amphibian species in Big Cypress National Preserve, was conducted from 2002 to 2003. The goals of the project were to create a georeferenced inventory of amphibian species, use new analytical techniques to estimate proportion of sites occupied by each species, look for any signs of amphibian decline (missing species, disease, die-offs, and so forth.), and to establish a protocol that could be used for future monitoring efforts. Several sampling methods were used to accomplish these goals. Visual encounter surveys and anuran vocalization surveys were conducted in all habitats throughout the park to estimate the proportion of sites or proportion of area occupied (PAO) by each amphibian species in each habitat. Opportunistic collections, as well as limited drift fence data, were used to augment the visual encounter methods for highly aquatic or cryptic species. A total of 545 visits to 104 sites were conducted for standard sampling alone, and 2,358 individual amphibians and 374 reptiles were encountered. Data analysis was conducted in program PRESENCE to provide PAO estimates for each of the anuran species. All of the amphibian species historically found in Big Cypress National Preserve were detected during this project. At least one individual of each of the four salamander species was captured during sampling. Each of the anuran species in the preserve was adequately sampled using standard herpetological sampling methods, and PAO estimates were produced for each species of anuran by habitat. This information serves as an indicator of habitat associations of the species and relative abundance of sites occupied, but it will also be useful as a comparative baseline for future monitoring efforts. In addition to sampling for amphibians, all encounters with reptiles were documented. The sampling methods used for detecting amphibians are also appropriate for many reptile species. These reptile locations are included in this report, but the number of reptile observations was not sufficient to estimate PAO for reptile species. We encountered 35 of the 46 species of reptiles believed to be present in Big Cypress National Preserve during this study, and evidence exists of the presence of four other reptile species in the Preserve. This study found no evidence of amphibian decline in Big Cypress National Preserve. Although no evidence of decline was observed, several threats to amphibians were identified. Introduced species, especially the Cuban treefrog (Osteopilus septentrionalis), are predators and competitors with several native frog species. The recreational use of off-road vehicles has the potential to affect some amphibian populations, and a study on those potential impacts is currently underway. Also, interference by humans with the natural hydrologic cycle of south Florida has the potential to alter the amphibian community. Continued monitoring of the amphibian species in Big Cypress National Preserve is recommended. The methods used in this study were adequate to produce reliable estimates of the proportion of sites occupied by most anuran species, and are a cost-effective means of determining the status of their populations.

Heteroepitaxy of Group IV and Group III-V semiconductor alloys for photovoltaic applications

Photovoltaic energy conversion represents a economically viable technology for realizing collection of the largest energy resource known to the Earth -- the sun. Energy conversion efficiency is the most leveraging factor in the price of energy derived from this process. This thesis focuses on two routes for high efficiency, low cost devices: first, to use Group IV semiconductor alloy wire array bottom cells and epitaxially grown Group III-V compound semiconductor alloy top cells in a tandem configuration, and second, GaP growth on planar Si for heterojunction and tandem cell applications.

Metal catalyzed vapor-liquid-solid grown microwire arrays are an intriguing alternative for wafer-free Si and SiGe materials which can be removed as flexible membranes. Selected area Cu-catalyzed vapor-liquid solid growth of SiGe microwires is achieved using chlorosilane and chlorogermane precursors. The composition can be tuned up to 12% Ge with a simultaneous decrease in the growth rate from 7 to 1 μm/min^-1. Significant changes to the morphology were observed, including tapering and faceting on the sidewalls and along the lengths of the wires. Characterization of axial and radial cross sections with transmission electron microscopy revealed no evidence of defects at facet corners and edges, and the tapering is shown to be due to in-situ removal of catalyst material during growth. X-ray diffraction and transmission electron microscopy reveal a Ge-rich crystal at the tip of the wires, strongly suggesting that the Ge incorporation is limited by the crystallization rate.

Tandem Ga_1-xIn_xP/Si microwire array solar cells are a route towards a high efficiency, low cost, flexible, wafer-free solar technology. Realizing tandem Group III-V compound semiconductor/Si wire array devices requires optimization of materials growth and device performance. GaP and Ga_1-xIn_xP layers were grown heteroepitaxially with metalorganic chemical vapor deposition on Si microwire array substrates. The layer morphology and crystalline quality have been studied with scanning electron microscopy and transmission electron microscopy, and they provide a baseline for the growth and characterization of a full device stack. Ultimately, the complexity of the substrates and the prevalence of defects resulted in material without detectable photoluminescence, unsuitable for optoelectronic applications.

Coupled full-field optical and device physics simulations of a Ga_0.51In_0.49P/Si wire array tandem are used to predict device performance. A 500 nm thick, highly doped "buffer" layer between the bottom cell and tunnel junction is assumed to harbor a high density of lattice mismatch and heteroepitaxial defects. Under simulated AM1.5G illumination, the device structure explored in this work has a simulated efficiency of 23.84% with realistic top cell SRH lifetimes and surface recombination velocities. The relative insensitivity to surface recombination is likely due to optical generation further away from the free surfaces and interfaces of the device structure.

Finally, GaP has been grown free of antiphase domains on Si (112) oriented substrates using metalorganic chemical vapor deposition. Low temperature pulsed nucleation is followed by high temperature continuous growth, yielding smooth, specular thin films. Atomic force microscopy topography mapping showed very smooth surfaces (4-6 Å RMS roughness) with small depressions in the surface. Thin films (~ 50 nm) were pseudomorphic, as confirmed by high resolution x-ray diffraction reciprocal space mapping, and 200 nm thick films showed full relaxation. Transmission electron microscopy showed no evidence of antiphase domain formation, but there is a population of microtwin and stacking fault defects.

LiNbO3：Cr：Cu晶体吸收特性及非挥发全息存储研究

研究了LiNbO3：Cr：Cu晶体的吸收特性，发现LiNbO3：Cr：Cu（含0．14wt．％Cr2O3和0．011wt．％CuO）晶体存在两个明显的吸收峰，中心波长分别位于480nm和660nm；随着Cr的含量逐渐减小，Cu的含量逐渐增大，短波段不存在明显吸收峰，掺Cr的含量越大，中心波长在660nm处的吸收越大；633nm红光虽然位于中心波长为660nm的吸收峰内，但它无助于光折变过程．分别采用390nm紫外光和488nm蓝光作为敏化光，514nm绿光作为记录光的记录方案，实现了非挥发全息记录，掺入适

I. The crystal structure of potassium bis(tricyanovinyl)amine. II. Nuclear magnetic resonance studies of alkali halide solutions. III. Elucidation of the intramolecular hydrogen bond in acetylacetone by the deuterium isotope effect on the chemical shift of the bridge hydrogen

Part I

Potassium bis-(tricyanovinyl) amine, K⁺N[C(CN)=C(CN)₂]₂^-, crystallizes in the monoclinic system with the space group Cc and lattice constants, a = 13.346 ± 0.003 Å, c = 8.992 ± 0.003 Å, B = 114.42 ± 0.02°, and Z = 4. Three dimensional intensity data were collected by layers perpendicular to b* and c* axes. The crystal structure was refined by the least squares method with anisotropic temperature factor to an R value of 0.064.

The average carbon-carbon and carbon-nitrogen bond distances in –C-CΞN are 1.441 ± 0.016 Å and 1.146 ± 0.014 Å respectively. The bis-(tricyanovinyl) amine anion is approximately planar. The coordination number of the potassium ion is eight with bond distances from 2.890 Å to 3.408 Å. The bond angle C-N-C of the amine nitrogen is 132.4 ± 1.9°. Among six cyano groups in the molecule, two of them are bent by what appear to be significant amounts (5.0° and 7.2°). The remaining four are linear within the experimental error. The bending can probably be explained by molecular packing forces in the crystals.

Part II

The nuclear magnetic resonance of ⁸¹Br and ¹²⁷I in aqueous solutions were studied. The cation-halide ion interactions were studied by studying the effect of the Li⁺, Na⁺, K⁺, Mg⁺⁺, Cs⁺ upon the line width of the halide ions. The solvent-halide ion interactions were studied by studying the effects of methanol, acetonitrile, and acetone upon the line width of ⁸¹Br and ¹²⁷I in the aqueous solutions. It was found that the viscosity plays a very important role upon the halide ions line width. There is no specific cation-halide ion interaction for those ions such as Mg⁺⁺, Di⁺, Na⁺, and K⁺, whereas the Cs⁺ - halide ion interaction is strong. The effect of organic solvents upon the halide ion line width in aqueous solutions is in the order acetone ˃ acetonitrile ˃ methanol. It is suggested that halide ions do form some stable complex with the solvent molecules and the reason Cs⁺ can replace one of the ligands in the solvent-halide ion complex.

Part III

An unusually large isotope effect on the bridge hydrogen chemical shift of the enol form of pentanedione-2, 4(acetylacetone) and 3-methylpentanedione-2, 4 has been observed. An attempt has been made to interpret this effect. It is suggested from the deuterium isotope effect studies, temperature dependence of the bridge hydrogen chemical shift studies, IR studies in the OH, OD, and C=O stretch regions, and the HMO calculations, that there may probably be two structures for the enol form of acetylacetone. The difference between these two structures arises mainly from the electronic structure of the π-system. The relative population of these two structures at various temperatures for normal acetylacetone and at room temperature for the deuterated acetylacetone were calculated.

Ultrafast double pulses ablation of Cr film on glass

Ultrafast lasers ablation of Cr film was investigated by using double-pulse method. Experimental results show that there exists a temporal ablation window effect with each of the double pulses adjusted just smaller than the threshold. When the delay between the double pulses is within the order of 400 ps, the ablation of Cr film could happen. When the delay between the double pulses is beyond the order of 400 ps, the ablation of Cr film would not happen, and the reflectivity from the surface of the Cr film shows a sharp rise at the same time. The two-temperature model was developed into the form of double pulses to explain the experimental phenomena. Furthermore, microbump structures were formed on the surface of Cr film after ablation by ultrafast double pulses. Their heights exhibit an obvious drop between 1 and 10 ps double pulses delay, which is involved with the electron-phonon coupling process according to the numerical simulation. These results should be helpful for understanding the dynamic processes during ultrafast lasers ablation of metal films. (C) 2008 Elsevier B.V. All rights reserved.

I. Fundamental limitations in microelectronics. II. Power Schottky diode design and comparison with the junction diode. III. Permittivity of strontium titanate

Part I

The physical phenomena which will ultimately limit the packing density of planar bipolar and MOS integrated circuits are examined. The maximum packing density is obtained by minimizing the supply voltage and the size of the devices. The minimum size of a bipolar transistor is determined by junction breakdown, punch-through and doping fluctuations. The minimum size of a MOS transistor is determined by gate oxide breakdown and drain-source punch-through. The packing density of fully active bipolar or static non-complementary MOS circuits becomes limited by power dissipation. The packing density of circuits which are not fully active such as read-only memories, becomes limited by the area occupied by the devices, and the frequency is limited by the circuit time constants and by metal migration. The packing density of fully active dynamic or complementary MOS circuits is limited by the area occupied by the devices, and the frequency is limited by power dissipation and metal migration. It is concluded that read-only memories will reach approximately the same performance and packing density with MOS and bipolar technologies, while fully active circuits will reach the highest levels of integration with dynamic MOS or complementary MOS technologies.

Part II

Because the Schottky diode is a one-carrier device, it has both advantages and disadvantages with respect to the junction diode which is a two-carrier device. The advantage is that there are practically no excess minority carriers which must be swept out before the diode blocks current in the reverse direction, i.e. a much faster recovery time. The disadvantage of the Schottky diode is that for a high voltage device it is not possible to use conductivity modulation as in the p i n diode; since charge carriers are of one sign, no charge cancellation can occur and current becomes space charge limited. The Schottky diode design is developed in Section 2 and the characteristics of an optimally designed silicon Schottky diode are summarized in Fig. 9. Design criteria and quantitative comparison of junction and Schottky diodes is given in Table 1 and Fig. 10. Although somewhat approximate, the treatment allows a systematic quantitative comparison of the devices for any given application.

Part III

We interpret measurements of permittivity of perovskite strontium titanate as a function of orientation, temperature, electric field and frequency performed by Dr. Richard Neville. The free energy of the crystal is calculated as a function of polarization. The Curie-Weiss law and the LST relation are verified. A generalized LST relation is used to calculate the permittivity of strontium titanate from zero to optic frequencies. Two active optic modes are important. The lower frequency mode is attributed mainly to motion of the strontium ions with respect to the rest of the lattice, while the higher frequency active mode is attributed to motion of the titanium ions with respect to the oxygen lattice. An anomalous resonance which multi-domain strontium titanate crystals exhibit below 65°K is described and a plausible mechanism which explains the phenomenon is presented.

E. U. Magisterio de Vitoria-Gasteiz. Plan general Practicum III. Comisión de prácticas, 4 de julio de 2014

[ES]Las Prácticas Escolares se realizarán en los dos ciclos de Educación Infantil (0-3, 3-6) y en los tres de Educación Primaria (1º-2º, 3º-4º, 5º-6º). Al tratarse de un Prácticum progresivo, cada estudiante cursa la materia a lo largo del segundo, tercer y cuarto curso (Prácticum I, Prácticum II y Prácticum III) con contenidos que tienen continuidad y que suponen un nivel de competencia superior respecto el anterior. Además, el alumnado que en 4º curso se matricule en el minor de Educación Física deberá realizar su periodo de prácticas junto a una maestra o maestro especialista en esta materia, quien tutorizará sus prácticas. El Prácticum supone para el alumnado una oportunidad de adquirir e integrar las habilidades, los conocimientos, las competencias y la práctica necesarios para el ejercicio de su profesión, así como una ocasión para reflexionar de forma individual y grupal acerca del aprendizaje realizado y de la práctica llevada a cabo.

Exámenes resueltos de matemáticas III LADE

En la asignatura de Matemáticas III, en la Licenciatura en Administración y Dirección de Empresas, se complementan los estudios de Algebra Lineal introducidos en Matemáticas I y se estudian en profundidad los problemas de programación lineal, imprescindibles en estos estudios. En la primera parte de esta asignatura se aborda el problema de la diagonalización de matrices y el estudio de las formas cuadráticas. La segunda parte de la asignatura se dedica a la programación lineal, incidiendo especialmente en el análisis gráfico de este tipo de tipo de problemas y en el método simplex, que permite resolver estos problemas cuando el número de variables aumenta. Así mismo, se insiste en el correcto planteamiento de estos problemas y en el análisis de sensibilidad. Todos estos conceptos son necesarios en los estudios de Administración y Dirección de Empresas (LADE). Esta publicación recoge la resolución de todos los exámenes propuestos en la asignatura de Matemáticas III, Licenciatura en Administración y Dirección de Empresas, en la Facultad de Ciencias Económicas y Empresariales de la UPV\EHU entre los cursos 2001-2002 y 2009-2010. Los exámenes están dispuestos en el orden en que se realizaron, esto es, los últimos que aparecen son los más recientes.

Relación de problemas resueltos de exámenes de la asignatura Matemáticas III para Economistas de la Licenciatura de Economía

Relación de problemas resueltos de exámenes de la asignatura Matemáticas III para Economistas de la Licenciatura de Economía desde febrero de 2001 hasta junio de 2010.

Zientzia eta Teknologia Fakultateko III. Ikerkuntza Jardunaldiak ; Enpresa eta Berrikuntza Teknologikoko Zentroen Aurkezpenerako VII. Jardunaldiak

[ES]El objetivo de estas jornadas es, por una parte, mostrar a nuestro alumnado la investigación que llevan a cabo los diferentes grupos de la facultad, de cara a despertar vocaciones investigadoras. Por otro lado, como en otras ocasiones, varias empresas y centros de innovación tecnológica presentarán al alumnado de los últimos cursos las posibilidades y los requisitos para su incorporación al mundo laboral

Condições de saúde bucal em atletas dos XV Jogos Pan-Americanos e III Jogos Parapan-Americanos, Rio de Janeiro, Brasil, 2007

O estudo epidemiológico transversal randomizado objetivou avaliar condições de saúde bucal nos competidores dos XV Jogos Pan-Americanos (JPA) e III Jogos Parapan-Americanos (JPPA), 2007. Foram enviados convites para 5.662 atletas (JPA) e 1.300 (JPPA). Radiografias panorâmicas digitais (RPD) foram utilizadas para o exame de triagem nos 2 eventos, e nos JPPA, os atletas também foram submetidos à avaliação do sangramento gengival interdental (SI) através de uma versão modificada do Índice de Sangramento Interdental de Eastman (EIBI). Foram obtidas RPDs de 410 atletas dos JPA, média de idade 24,38 (dp5,35), 55% homens; e de 118 dos atletas dos JPPA, média de idade de 32,3 (dp9,53), 77,97% homens. 121 competidores (JPPA) foram avaliados para SI: 78,51% homens, média de idade 32,6(dp9,6), e foram separados em grupos (G), conforme sua deficiência física: GI c/ deficiência visual (DV), com 2 subgrupos: GI-a: DV tardia e GI-c-: DV congênita/precoce; GII- deficiência de membro superior; com 1 subgrupo: GII-t: deficiência/ausência bilateral; GIII- deficiência de membro inferior (grupo controle). As RPDs foram examinadas por 1 examinador com o Kodak Dental Imaging(v6.7). A frequência e a distribuição do SI foram calculadas, e os grupos foram comparados. Resultados da triagem com RPDs, representados por número de observações(média por atleta) JPA//número de observações(média por atleta JPPA: Dentes erupcionados/ hígidos: 9097(22,19)//2451(20,77); Ausentes: 803(1,96 //405(3,43); Não erupcionados ou impactados: 330(0,80)//52(0,44); Parcialmente erupcionados e/ou hígidos: 109(0,27)//20(0,17); Cárie extensa: 261(0,64)//62(0,53); Cárie extensa e lesão periapical: 96(0,23)//50(0,42); Tratamento endodôntico e lesão periapical: 24(0,06)//13(0,11); Restaurados: 2298(5,60)//670(5,68); Imagens radiolúcidas patológicas circunscritas: 23(0,06)//0; Raízes-residuais: 27(0,07)//22(0,19); Implantes:6(0,01)//5(0,04); Dentes anteriores fraturados: 13 (0,03)//3(0,03); Molares bandados: 26(0,06)//11(0,09); Dentes anômalos: 7(0,02)//12(0,10). Resultados para SI: G-I>G-III (p=0.0002);GI-c>GI-a (p=0,042). Homens exibiram > freqüência de SI (3,6%+1,7) que mulheres (0,8%+0,5), p<0,01. Conclusões: Os dados das 2 populações de atletas mostraram que há uma grande variação na saúde bucal entre os indivíduos avaliados. Diversas condições com potencial de influenciar o desempenho esportivo dos atletas foram detectadas através de radiografias panorâmicas digitais, sugerindo que um programa de saúde bucal deve ser incluído como parte da preparação destes indivíduos.A avaliação da frequência e distribuição de sangramento gengival interdental em uma população de atletas que competiu nos III Jogos Parapan-Americanos, revelou que o tipo de deficiência ou limitação física dos competidores é um fator que influencia na saúde gengival desses indivíduos. O planejamento de um programa de saúde bucal para esta população deve ser adaptado às diferentes limitações de cada atleta.

Efficacy and safety of autologous platelet rich plasma for the treatment of vascular ulcers in primary care: Phase III study

Background: Vascular ulcers are commonly seen in daily practice at all levels of care and have great impact at personal, professional and social levels with a high cost in terms of human and material resources. Given that the application of autologous platelet rich plasma has been shown to decrease healing times in various different studies in the hospital setting, we considered that it would be interesting to assess the efficacy and feasibility of this treatment in primary care. The objectives of this study are to assess the potential efficacy and safety of autologous platelet rich plasma for the treatment of venous ulcers compared to the conventional treatment (moist wound care) in primary care patients with chronic venous insufficiency (C, clinical class, E, aetiology, A, anatomy and P, pathophysiology classification C6). Design: We will conduct a phase III, open-label, parallel-group, multicentre, randomized study. The subjects will be 150 patients aged between 40 and 100 years of age with an at least 2-month history of a vascular venous ulcer assigned to ten primary care centres. For the treatment with autologous platelet rich plasma, all the following tasks will be performed in the primary care setting: blood collection, centrifugation, separation of platelet rich plasma, activation of coagulation adding calcium chloride and application of the PRP topically after gelification. The control group will receive standard moist wound care. The outcome variables to be measured at baseline, and at weeks 5 and 9 later include: reduction in the ulcer area, Chronic Venous Insufficiency Quality of Life Questionnaire score, and percentage of patients who require wound care only once a week. Discussion: The results of this study will be useful to improve the protocol for using platelet rich plasma in chronic vascular ulcers and to favour wider use of this treatment in primary care.