949 resultados para Celulas germinativas - Ultra-estrutura


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The thesis is divided into nine chapters including introduction. Mainly we determine ultra L-topologies in the lattice of L- topologies and study their properties. We nd some sublattices in the lattice of L-topologies and study their properties. Also we study the lattice structure of the set of all L-closure operators on a set X.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A printed compact coplanar waveguide fed triangular slot antenna for ultra wide band (UWB) communication systems is presented. The antenna comprises of a triangular slot loaded ground plane with a T shaped strip radiator to enhance the bandwidth and radiation. This compact antenna has a dimension of 26mm×26mm when printed on a substrate of dielectric constant 4.4 and thickness 1.6mm. Design equations are implemented and validated for different substrates. The pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity and virtually steady group delay. The simulation and experiment reveal that the proposed antenna exhibits good impedance match, stable radiation patterns and constant gain and group delay over the entire operating band

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper presents a compact planar Ultra Wide Band ¯lter employing folded stepped impedance resonators with series capacitors and dumb bell shaped defected ground structures. An interdigital quarter wavelength coupled line is used for achieving the band pass characteristics. The transmission zeros are produced by stepped impedance resonators. The ¯lter has steep roll o® rate and good attenuation in its lower and upper stop bands, contributed by the series capacitor and defected ground structures respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper presents a maximally flat compact planar filter employing folded Stepped Impedance Resonators (SIR) and Complementary Split Ring Resonators (CSRR), for Ultra Wide Band (UWB) applications. An interdigital quarter wavelength coupled line is used for achieving the band pass characteristics. The filter has low insertion loss in its pass band and steep roll off rate and good attenuation in its lower and upper stop bands. The measured microwave characteristics of the fabricated filter show good agreement with the simulated response

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Zinc ferrite belongs to the class of normal spinels where it is assumed to have a cation distribution of Zn2`(Fe3`)2(O2~)4, and it is purported to be showing zero net magnetisation. However, there have been recent reports suggesting that zinc ferrite exhibits anomaly in its magnetisation. Zinc ferrite samples have been prepared by two di¤erent routes and have been analysed using low energy ion scattering, Mo¬ ssbauer spectroscopy and magnetic measurements. The results indicate that zinc occupies octahedral sites, contrary to the earlier belief that zinc occupies only the tetrahedral sites in a normal spinel. The amount of zinc on the B site increases with decrease in particle size. The LEIS results together with the Mo¬ ssbauer results and the magnetic measurements lead to the conclusion that zinc occupies the B site and the magnetisation exhibited by ultraÞne particles of zinc is due to short range ordering

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Information display technology is a rapidly growing research and development field. Using state-of-the-art technology, optical resolution can be increased dramatically by organic light-emitting diode - since the light emitting layer is very thin, under 100nm. The main question is what pixel size is achievable technologically? The next generation of display will considers three-dimensional image display. In 2D , one is considering vertical and horizontal resolutions. In 3D or holographic images, there is another dimension – depth. The major requirement is the high resolution horizontal dimension in order to sustain the third dimension using special lenticular glass or barrier masks, separate views for each eye. The high-resolution 3D display offers hundreds of more different views of objects or landscape. OLEDs have potential to be a key technology for information displays in the future. The display technology presented in this work promises to bring into use bright colour 3D flat panel displays in a unique way. Unlike the conventional TFT matrix, OLED displays have constant brightness and colour, independent from the viewing angle i.e. the observer's position in front of the screen. A sandwich (just 0.1 micron thick) of organic thin films between two conductors makes an OLE Display device. These special materials are named electroluminescent organic semi-conductors (or organic photoconductors (OPC )). When electrical current is applied, a bright light is emitted (electrophosphorescence) from the formed Organic Light-Emitting Diode. Usually for OLED an ITO layer is used as a transparent electrode. Such types of displays were the first for volume manufacture and only a few products are available in the market at present. The key challenges that OLED technology faces in the application areas are: producing high-quality white light achieving low manufacturing costs increasing efficiency and lifetime at high brightness. Looking towards the future, by combining OLED with specially constructed surface lenses and proper image management software it will be possible to achieve 3D images.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El Zimbardo Time Perspective Inventory – ZTPI (Zimbardo & Boyd, 1999) es una escala compuesta por cinco factores (pasado positivo, pasado negativo, presente hedonista, presente fatalista y futuro) que evalúa la perspectiva temporal de forma multidimensional superando, de esta forma, una de las limitaciones señaladas en otros instrumentos creados en el pasado. El objetivo de este estudio es analizar la estructura factorial de una versión portuguesa del ZTPI en una muestra de 277 estudiantes universitarios portugueses con edades comprendidas entre los 18 y los 53 años (M = 22, DE = 5.43). Fueron encontrados 5 factores que explican 35.25% de la varianza total. Estos resultados son muy parecidos a los expuestos por Zimbardo y Boyd (1999) en la publicación original del instrumento.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

las empresas como instituciones sociales, no sólo están comprometidas con la comunidad en la generación de bienes y servicios de calidad, sino también con una gestión ambiental integral, en donde se administren los residuos

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O ensaio deseja indicar pistas para a projectação em Arquitectura, através duma introdução à Teoria Paradigmática que caracteriza e define a nossa contemporaneidade e a Estrutura da Forma. Aflorando a Teoria do Caos e textos de Teoria de Arte que desejam ser rupturas epistemológicas ou seus indicadores, sugere-nos técnicas que pela criatividade se tornam dispositivos para o projecto em Arquitectura. Por fim, é apresentado um caso de estudo de um arquitecto da actualidade, a proposta de Peter Eisenman para Cannaregio. As consequências ambicionadas pelo ensaio são as motivações chave para a criação duma arquitectura mais próxima dos anseios sociais e que através delas existam contributos mais ousados e criativos para uma arquitectura que seja verdadeiramente expressão do pulsar da nossa sociedade.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The exercise of disciplinary action, for the practice of misconduct by a lawyer or trainee lawyer, is the sole responsibility of the O.A., as professional body representative of their peers. The disciplinary procedure prescribed in the statute of the O.A., presents a framework for an integrated accusatory principle of research. The participation of the rapporteur of the disciplinary proceedings in the voting of the resolution imposing a disciplinary sanction is substantively unconstitutional for violating paragraph 5 of article 32nd of the Portuguese Constitution. The requirement to comply with this legislation stems, ultimately, from the similar nature of the fundamental rights of the accused lawyer or trainee lawyer to the rights, freedoms and guarantees protected in criminal proceedings.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Changes to the rules concerning the admissibility of statements read in trial, previously provided by the defendant, despite its apparent simplicity, undermine the criminal procedural architecture projected from the constitutional structure accusatory criminal procedure. The principle that in judging only can be valued the evidence produced before the judge gives rise the production of evidence by the prosecution in the investigation phase.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Com base num estudo empírico realizado entre 2001 e 2004, que incidiu sobre jovens leigos organizados formalmente na estrutura da Igreja Católica-romana e sujeitos a um processo de socialização religiosa institucional estruturado, propomo-nos discutir a incidência do processo de recomposição do religioso entre os jovens católicos praticantes no contexto português. Os resultados apontam, por um lado, para uma progressiva erosão das práticas e representações associadas à doutrina Católica-romana – o que se traduz numa heterogeneidade de posicionamentos que oscilam entre o integrismo intransigente e o progressismo radical – e por outro, verificámos que o envolvimento emocional, em detrimento do processo estruturado de formação, é neste caso o elemento central na vinculação ideológica confessional.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este Artigo é o relato da descoberta de uma Estrutura do Valor Patrimonial . Independente quer dos «objectos» [documentos, colecções e museus] que foram sendo o Património, quer dos «usos» [expografias, representações, narrativas mediações e serviços] que lhe foram sendo dados nas épocas histórico - sociais que se sucederam no percurso humano. Este resultado remete, num primeiro momento, para a discussão de cinco qu estões - chave, cujas consequências para a Museologia se repercutem quer no plano teórico quer no plano prático. Sendo uma delas, a de substituir o «instinto de coleccionar» na teoria museológica