Defects in PN junctions and MOS capacitors observed using thermally stimulated current and capacitance measurements, videotape script /

Includes bibliographical references (p. 14).

Istoria del cielo considerato secondo le idee de' poeti, de' filosofi e di Mosè : oue si fa vedere 1º L'origine del cielo poetico. 2º L'errore de' filosofi intorno alla fabbrica del cielo e della terra. 3º La conformità dell'esperienza con la sola fisica di Mosè.

Mode of access: Internet.

Lettera del ch. sig. abate Francesco Cancellieri al sig. canonico Domenico Moreni sopra la statua di Mosé del Buonarroti : con la Biblioteca mosaica, o sia, Catalogo degli scrittori intorno a questo profeta, legislatore, e condottiere del popolo ebreo.

Edited by D. Moreni.

Commanders manual : Hercules fire control crewman, MOS 16C.

May 10, 1978.

Synekdēmos hieratikos periechōn tas duo pros Timotheon kai tēn pros Titon Epistolas : tou Apostolou Paulou me mian koinēn metaphrasin kai exēgēsin diexodikēn.

Includes bibliographical references.

De neamul Moldovenilor : din ce tarǎ au eșit strǎmoșii lor /

At head of title: Comisia istoricǎ a României.

Synthesis and characterization of mesoporous nickel oxide and its application to electrochemical capacitor

Mesoporous Ni(OH)(2) was synthesized using cationic surfactant as template and urea as hydrolysis-controlling agent. Mesoporous NiO with centralized pore size distribution was obtained by calcining Ni(OH)(2) at different temperatures. The BET specific surface area reaches 477.7 m(2).g(-1) for NiO calcined at 523 K. Structure characterizations indicate the polycrystalline pore wall of mesoporous nickel oxide. The pore-formation mechanism is also deduced to be quasi-reverse micelle mechanism. Cyclic voltammetry shows the good capacitive behavior of these NiO samples due to its unique mesoporous structure when using large amount of NiO to fabricate electrode. Compared with NiO prepared by dip-coating and cathodic precipitation methods, this mesoporous NiO with controlled pore structure can be used in much larger amount to fabricate the electrode and still maintains high specific capacitance and good capacitive behavior.

Switched capacitor DC-DC converters for HVDC applications

DC distribution and transmission provides an efficient, cost effective and reliable alternative to traditional AC systems for offshore wind farm integration. High power DC-DC converters are key components to realise future offshore voltage DC grids and multi-terminal HVDC systems. Different DC-DC converter topologies have been proposed for this application. The aim of this paper is to investigate the viability of Switched Capacitor (SC) converters in high power application particularly the interconnection of offshore windfarms to a medium voltage DC grid. In addition, a comparison of alternative topologies that have been proposed will be presented. Simulation and experimental results are provided to verify the analysis.

The effect of circuit parasitics on resonant switched capacitor converters

Switched Capacitor (SC) converters have been used for several years in low-power, power electronic energy conversion systems. However, because of their attractive features such as low-weight and high-density energy conversion and with the emergence of new circuit topologies and SiC switching devices, these circuits have recently been proposed for higher power applications. The resonant switched capacitor topology is a good candidate for high-power due to its very low-switching loss, but circuit parasitic inductance and resistance can have a significant effect on the resonant frequency of each cell. This paper discusses the influence of these parasitics on the performance of the converter and proposes a method by which these parasitics can be estimated. Simulation results and measurements from a hardware prototype are used to validate the technique.

Modelo comportamental do capacitor ferroelétrico como unidade básica de neurônios artificiais e sua implementação em FPGA

This work proposes the use of the behavioral model of the hysteresis loop of the ferroelectrics capacitor as a new alternative to the usually costly techniques in the computation of nonlinear functions in artificial neurons implemented on reconfigurable hardware platform, in this case, a FPGA device. Initially the proposal has been validated by the implementation of the boolean logic through the digital models of two artificial neurons: the Perceptron and a variation of the model Integrate and Fire Spiking Neuron, both using the model also digital of the hysteresis loop of the ferroelectric capacitor as it’s basic nonlinear unit for the calculations of the neurons outputs. Finally, it has been used the analog model of the ferroelectric capacitor with the goal of verifying it’s effectiveness and possibly the reduction of the number of necessary logic elements in the case of implementing the artificial neurons on integrated circuit. The implementations has been carried out by Simulink models and the synthesizing has been done through the DSP Builder software from Altera Corporation.

Estudo da sinterização e oxidação anódica na produção de um capacitor eletrolítico de nióbio

It seeks to find an alternative to the current tantalum electrolytic capacitors in the market due to its high cost. Niobium is a potential replacement for be lighter and cheaper than tantalum. They belong to the same table group periodically and thus exhibit several physical and chemical properties similar. Niobium is used in many technologically important applications, and Brazil has the largest reserves, around 96%. These electrolytic capacitors have high specific capacitance, so they can store high energy in small volumes compared to other types of capacitors. This is the main attraction of this type of capacitor because is growing demand in the production of capacitors with capacitance specifies increasingly high, this because of the miniaturization of various devices such as GPS devices, televisions, computers, phones and many others. The production route of the capacitor was made by powder metallurgy. The initial niobium poder was first characterized by XRD, SEM and laser particle size to then be sieved into particle size 400mesh. The powder was then compacted at pressure of 150MPa and sintered at 1400, 1450 and 1500°C using two sintering time 30 and 60min. Sintering is an important part of the process as it affects properties as porosity and surface cleaning of the samples, which greatly affected the quality of the capacitor. After sintering the samples were underwent a process of anodic oxidation (anodizing), which created a thin film of niobium pentoxide over the whole surface of the sample, this film is the dielectric capacitor. The anodizing process variables influenced a lot in film formation and consequently the capacitor. The samples were characterized by electrical measurements of capacitance, loss factor and ESR (equivalent series resistance). The sintering has affected the porosity and in turn the specific area of the samples. The capacitor area is directly related to the capacitance, that is, the higher the specific area is the capacitance. Higher sintering temperatures decrease the surface area but eliminate as many impurities. The best results were obtained at a temperature of 1400°C with 60 minutes. The most interesting results were compared with the specific capacitance and ESR for all samples.

Estudo da sinterização e oxidação anódica na produção de um capacitor eletrolítico de nióbio

It seeks to find an alternative to the current tantalum electrolytic capacitors in the market due to its high cost. Niobium is a potential replacement for be lighter and cheaper than tantalum. They belong to the same table group periodically and thus exhibit several physical and chemical properties similar. Niobium is used in many technologically important applications, and Brazil has the largest reserves, around 96%. These electrolytic capacitors have high specific capacitance, so they can store high energy in small volumes compared to other types of capacitors. This is the main attraction of this type of capacitor because is growing demand in the production of capacitors with capacitance specifies increasingly high, this because of the miniaturization of various devices such as GPS devices, televisions, computers, phones and many others. The production route of the capacitor was made by powder metallurgy. The initial niobium poder was first characterized by XRD, SEM and laser particle size to then be sieved into particle size 400mesh. The powder was then compacted at pressure of 150MPa and sintered at 1400, 1450 and 1500°C using two sintering time 30 and 60min. Sintering is an important part of the process as it affects properties as porosity and surface cleaning of the samples, which greatly affected the quality of the capacitor. After sintering the samples were underwent a process of anodic oxidation (anodizing), which created a thin film of niobium pentoxide over the whole surface of the sample, this film is the dielectric capacitor. The anodizing process variables influenced a lot in film formation and consequently the capacitor. The samples were characterized by electrical measurements of capacitance, loss factor and ESR (equivalent series resistance). The sintering has affected the porosity and in turn the specific area of the samples. The capacitor area is directly related to the capacitance, that is, the higher the specific area is the capacitance. Higher sintering temperatures decrease the surface area but eliminate as many impurities. The best results were obtained at a temperature of 1400°C with 60 minutes. The most interesting results were compared with the specific capacitance and ESR for all samples.

Thermal stability study of AlGaN/GaN MOS-HEMTs using Gd2O3 as gate dielectric

Thermal stability of AlGaN/GaN MOS-HEMTs and -diodes using Gd_(2)O_(3) are investigated by means of different thermal cycles and storage tests up to 500ºC for one week. IV DC and pulsed characteristics of the devices before and after the processes are evaluated and compared with conventional HEMTs. Results show that the devices with Gd_(2)O_(3) dielectric layer have lower leakage current and a more stable behavior during thermal treatment processes compared with conventional devices. In fact, an excellent on/off ratio of about 108 and a stable V_(t) is observed after storage at high temperature. The beneficial effects of Gd_(2)O_(3) on trapping effects of MOS-HEMTs are also dis-cussed.

A expressão plástica nas mãos das crianças

Relatório elaborado para obtenção do grau de mestre em educação pré-escolar

Escola & Pais de Mãos Dadas : Um Projecto de Intervenção Educativa

"Este livro explora os desafios, os dilemas e as contradições que fazem das relações entre os pais e os professores um assunto simultaneamente aliciante e complexo, problematiza o modo como estas relações têm sido concebidas e concretizadas, discute as modalidades alternativas de articulação e aponta para novos territórios nos quais estas relações se podem alargar, desenvolver e prosperar."