Voltammetric characterization of stepped platinum single crystal surfaces vicinal to the (110) pole

Platinum stepped surfaces vicinal to the (1 1 0) crystallographic pole have been investigated voltammetrically in 0.1 M HClO(4) and 0.1 M H(2)SO(4) solutions. Changes in the voltammetric profile with the step density suggest the existence of two types of surface sites, that has been ascribed to linear and bidimensional domains. This result indicates the existence of important restructuring processes that separate the real surface distribution from the nominal one. The electronic properties of the surfaces have been characterized with the CO charge displacement method and the potential of zero total charge has been calculated as a function of the step density. (c) 2009 Elsevier B.V. All rights reserved.

Product verification and defect repair - status and considerations

Product verifications have become a cost-intensive and time-consuming aspect of modern electronics production, but with the onset of an ever-increasing miniaturisation, these aspects will become even more cumbersome. One may also go as far as to point out that certain precision assembly, such as within the biomedical sector, is legally bound to have 0 defects within production. Since miniaturisation and precision assembly will soon become a part of almost any product, the verifications phases of assembly need to be optimised in both functionality and cost. Another aspect relates to the stability and robustness of processes, a pre-requisite for flexibility. Furthermore, as the re-engineering cycle becomes ever more important, all information gathered within the ongoing process becomes vital. In view of these points, product, or process verification may be assumed to be an important and integral part of precision assembly. In this paper, product verification is defined as the process of determining whether or not the products, at a given phase in the life-cycle, fulfil the established specifications. Since the product is given its final form and function in the assembly, the product verification normally takes place somewhere in the assembly line which is the focus for this paper.

Optical Characterization and Optimization of Display Components : Some Applications to Liquid-Crystal-Based and Electrochromics-Based Devices

This dissertation is focused on theoretical and experimental studies of optical properties of materials and multilayer structures composing liquid crystal displays (LCDs) and electrochromic (EC) devices. By applying spectroscopic ellipsometry, we have determined the optical constants of thin films of electrochromic tungsten oxide (WOx) and nickel oxide (NiOy), the films’ thickness and roughness. These films, which were obtained at spattering conditions possess high transmittance that is important for achieving good visibility and high contrast in an EC device. Another application of the general spectroscopic ellipsometry relates to the study of a photo-alignment layer of a mixture of azo-dyes SD-1 and SDA-2. We have found the optical constants of this mixture before and after illuminating it by polarized UV light. The results obtained confirm the diffusion model to explain the formation of the photo-induced order in azo-dye films. We have developed new techniques for fast characterization of twisted nematic LC cells in transmissive and reflective modes. Our techniques are based on the characteristics functions that we have introduced for determination of parameters of non-uniform birefringent media. These characteristic functions are found by simple procedures and can be utilised for simultaneous determination of retardation, its wavelength dispersion, and twist angle, as well as for solving associated optimization problems. Cholesteric LCD that possesses some unique properties, such as bistability and good selective scattering, however, has a disadvantage – relatively high driving voltage (tens of volts). The way we propose to reduce the driving voltage consists of applying a stack of thin (~1µm) LC layers. We have studied the ability of a layer of a surface stabilized ferroelectric liquid crystal coupled with several retardation plates for birefringent color generation. We have demonstrated that in order to accomplish good color characteristics and high brightness of the display, one or two retardation plates are sufficient.

November 2001: Scryers, Crystal Balls, and the Future

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Crystal structure of Bn IV in complex with myristic acid: A Lys49 myotoxic phospholipase A(2) from Bothrops neuwiedi venom

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Methodology for fast evaluation of Bacillus thuringiensis crystal protein content

O desenvolvimento da produção e uso do Bacillus thuringiensis no Brasil em escala comercial enfrenta certas dificuldades, entre elas o estabelecimento de metodologias para a quantificação de produtos tóxicos a serem comercializados. Atualmente, a quantidade de toxinas é expressa como porcentagem do total de proteínas presentes em amostras em consideração. Tal metodologia, entretanto, não mede a quantidade real de uma determinada proteína presente em um produto qualquer, além do fato de diferentes linhagens bacterianas possuírem diferentes genes codificadores para endotoxinas e mesmo para b-toxina. Desde que os diferentes tipos de toxinas apresentam diferentes características antigências, este trabalho tem como objetivo a utilização de técnicas imunológicas para quantificar específicamente o conteúdo de proteína cristal presente em diferentes amostras. A proteína cristal produzida pela subespécie B. thuringiensis var. israelensis foi purificada por ultracentrifugação e utilizada para imunizar coelhas e produzir soros hiperimunes. Tais soros foram posteriormente usados para avaliar o nível de proteína cristal em bioinseticidas comerciais e em culturas de laboratório desta bactéria utilizando-se a técnica do imunodot. Os resultados foram obtidos por comparação de reações com concentrações conhecidas de proteína cristal permitindo assim avaliar com segurança os níveis desta proteína em várias preparações.

Aorticopulmonary septal defect in a dog: case report

Na avaliação da dispneia pós-exercício em uma cadela de 10 meses de idade, não castrada e sem raça definida, foi detectado sopro sistólico leve grau II/VI. A comunicação entre a aorta ascendente e o tronco pulmonar, observada pela presença de fluxo contínuo logo abaixo das valvas semilunares, à ecoDopplercardiografia, foi confirmada pela cirurgia. Após o procedimento cirúrgico, a cadela apresentou boa condição clínica e ausência de dispneia mesmo ao exercício. Ressalta-se a importância do diagnóstico precoce e preciso para o sucesso terapêutico. Este é o primeiro relato brasileiro dessa rara doença e a única cirurgia, bem sucedida, descrita na literatura veterinária consultada.

Vanadium complexes with thiosemicarbazones: Synthesis, characterization, crystal structures and anti-Mycobacterium tuberculosis activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Factors affecting nucleolytic efficiency of some ternary metal complexes with DNA binding and recognition domains. Crystal and molecular structure of Zn(phen)(edda)

The binding selectivity of the M(phen)(edda) (M = Cu, Co, Ni, Zn; phen = 1,10-phenanthroline, edda = ethylenediaminediacetic acid) complexes towards ds(CG)(6), ds(AT)(6) and ds(CGCGAATTCGCG) B-form oligonucleotide duplexes were studied by CD spectroscopy and molecular modeling. The binding mode is intercalation and there is selectivity towards AT-sequence and stacking preference for A/A parallel or diagonal adjacent base steps in their intercalation. The nucleolytic properties of these complexes were investigated and the factors affecting the extent of cleavage were determined to be: concentration of complex, the nature of metal(11) ion, type of buffer, pH of buffer, incubation time, incubation temperature, and the presence of hydrogen peroxide or ascorbic acid as exogenous reagents. The fluorescence property of these complexes and its origin were also investigated. The crystal structure of the Zn(phen)(edda) complex is reported in which the zinc atom displays a distorted trans-N4O2 octahedral geometry; the crystal packing features double layers of complex molecules held together by extensive hydrogen bonding that inter-digitate with adjacent double layers via pi...pi interactions between 1,10-phenanthroline residues. The structure is compared with that of the recently described copper(II) analogue and, with the latter, included in molecular modeling. (C) 2008 Elsevier B.V. All rights reserved.

Crystal structure, DNA binding studies, nucleolytic property and topoisomerase I inhibition of zinc complex with 1,10-phenanthroline and 3-methyl-picolinic acid

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermally activated exchange narrowing of the Gd3+ ESR fine structure in a single crystal of Ce1-xGdxFe4P12 (x approximate to 0.001) skutterudite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Wannier functions of a one-dimensional photonic crystal with inversion symmetry

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Synthesis and characterization of mono and polymeric cyclopalladated compounds: Crystal and molecular structure of [{Pd(dmba)(ONO2)}(2)(mu-pz)] center dot H2O (pz = pyrazine)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Large segmental radius and ulna defect treated by bone transportation with the Ilizarov technique

An 8-year-old male Boxer with a severely contaminated open fracture of the left radius and ulna fracture, produced by a helicopter propeller, was treated using bone transport by the Ilizarov method. Extensive diaphyseal bone loss and soft-tissue vascular damage were present. The radius and ulna were stabilised with an Ilizarov ring external fixator. The bone defect was partially shortened and restored by gradual transport of a bone segment created from proximal segments of the radius and ulna. The external fixator was removed 4fi months after the beginning of the latency period, due to instability caused by osteolysis around the wires. A cast was placed for 3 weeks. Although the bone transport had resulted in formation of approximately 4 cm of bone, the antebrachium showed approximately 50% shortening when compared to the contralateral limb. The infection was eradicated, and the dog was able to bear weight on the operated limb when walking.

Alveolar osseous defect in rat for cell therapy. Preliminary report

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)