Outmane Oubram

Transport and Electronic Properties of Two Dimensional Electron Gas in Delta-Migfet in GaAs

The objective of this work is to analyze electronic transport phenomena, due to ionized impurity scattering in δ-MIGFET (Delta-Multiple Independent Gate Field Effect Transistor). In this work, we report theoretical results for electronic transport in a delta-MIGFET using the device electronic structure and analytical expression of mobility and conductivity. The results show that the analytical mobility and conductivity are a good way to analyze Received 13 August 2010, Accepted 14 October 2010, Scheduled 10 November 2010 Corresponding author: Outmane Oubram (oubram@uaem.mx). † Also with Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, Mexico D.F 04510, Mexico.

Search for Optimum Operating Conditions for a Water Purification Process Integrated to a Heat Transformer with Energy Recycling using Artificial Neural Network Inverse Solved by Genetic and Particle Swarm Algorithms

The coefficient of performance (COP) for a water purification process integrated to an absorption heat transformer with energy recycling was optimized using the artificial intelligence. The objective of this paper is to develop an integrated approach using artificial neural network inverse (ANNi) coupling with optimization methods: genetic algorithms (GAs) and particle swarm algorithm (PSA). Therefore, ANNi was solved by these optimization methods to estimate the optimal input variables when a COP is required. The paper adopts two cases studies to accomplish the comparative study. The results illustrate that the GAs outperforms the PSA. Finally, the study shows that the GAs based on ANNi is a better optimization method for control on-line the performance of the system, and constitutes a very promising framework for finding a set of “good solutions”.

TRANSPORT PROPERTIES OF DELTA DOPED FIELD EFFECT TRANSISTOR

The first calculation of mobility and conductivity between source and drain as function of gate voltage in a δ-doped Field Effect Transistor is presented. The calculation was performed with a model for the δ-FET that was shown in (1). The mobility was calculated using a phenomenological expression that was presented in (2). That expression does not have empirical form, neither empirical parameter. For the first time a phenomenological expression of the conductivity is presented, which is derived from the mobility expression. The conductivity shows three different regions: a parabolic region and two linear regions. The parabolic region represents the region at which the conduction channel begins to close. On the other hand, the mobility shows a more different behavior. In the mobility there are four regions. These regions correspond to the disappearance of the different conduction channels that form the subbands of the delta- doped quantum well. The different behavior between mobility and conductivity relies on the depletion of the delta-doped quantum well as the gate potential grows.

TRANSPORT AND ELECTRONIC PROPERTIES OF THE GaAs ALD-FET

According to the scaling-down theory, the ALD-FET (Atomic Layer Doping-Field Efiect Transistor) structure has attracted a lot of attention in view of its uses for developing devices with very short channels and for achieving very-high-speed operation. Therefore, there is a strong need to obtain an accurate understanding of carrier transport (mobility and conductivity) in such devices. In this work, we report the carrier transport based on the electronic structure of devices. Our results include analytical expressions of both mobility and conductivity. Our analytical expressions for the mobility and conductivity allow us to analyze transport in ALD-FET. We report regions where this device operates in digital and analogue mode. These regions are delimited in terms of intrinsic and extrinsic parameters of the system. The width of the Ohmic region as well as the NDR (Negative Difierential Resistance) properties of the system are also characterized.

Intelligent Recognition System of Myoelectric Signals of Human Hand Movement

This paper presents the recognition of myoelectric signals algorithm design thru artificial neural network architecture, for the manufacture of a prototype of human hand prosthesis. At the beginning of the project the myoelectric sensor was designed to help capture the signals that correspond to the movement of each finger of a human hand. A database was generated with captured myoelectric signals, which was used for the training of artificial neural networks (ANN), obtaining the weights and bias. The performance of the architecture was evaluated with statistical criteria for the validation of ANN, comparing between simulated data and experimental data. It was found, that the best architecture in this project has 7 neurons in the hidden layer, one in the output layer and 96% correlation coefficient, this architecture is the number 7 in Table 1 which contains a performance report learning algorithm of the different architectures proposed.

Nonlinear optical absorption in δ-MIGFET transistor modulated by electrical field and contact voltage

The theoretical study of linear and nonlinear optical absorption in a GaAs n-type δ-MIGFET transistor is preformed taking into account the effects of applied electric field and contact voltage. From our results, it is found that the position and the magnitude of the linear, nonlinear and total absorption coefficient are quite sensitive to electric field and voltage contact. Besides, the incident optical intensity has a great effect on these optical quantities. These properties are desirable for controlling the optical absorption in optical transistor application.

The effects of the touch voltage and hydrostatic pressure on the optical absorption of Delta-MIGFET transistor

The combined effects of hydrostatic pressure and voltage contact on subband structure and optical transitions in GaAs delta-MIGFET (Delta-Multiple Independent Gate Field Effect Transistor) have been theoretically studied. Results obtained show the optical absorption is quite sensitive to the applied hydrostatic pressure and contact voltage. These can be suitable for good optical performance and various infrared optical device applications and can be easily obtained by tuning the voltage contact and hydrostatic pressure strength.

Simulation with a kit to power system and load flow analysis and Voltage Stability

This work presents a development kit to simulate the behavior of load flow an Voltage Stability of a power system. The network is designed and implemented to be useful as a tool in engineering studies and laboratory practices; also the measurement of steady state is compared with its digital behavior simulation using Power World software. The system configuration has been extracted from one similar typical network used in the literature of power systems. Basically it has an infinity bus, two generators, loads, six transmission lines that permit also synchronization tests and making digital and analog measurements. The generators, loads as a constant impedance (resistors, capacitors and reactors) and the infinity bus belong to a Lab-Volt commercial brand, transmission short line models are designed using easy acquisition materials. In addition the use of a digital instrument of AEMC series permits the capture of information.

Study on the structural and magnetic properties of Ru 1−x Mo x Sr 2 GdCu 2 O 8±z system

The structural and magnetic properties of Ru_1-xMo_xSr₂GdCu₂O₈ with 0.0 ≤ x ≤ 0.50 were investigated through Mo substitution in the Ru sites. Samples were synthesized by solid-state reaction at ambient pressure at temperature between 960 °C and 1060 °C. X-ray diffraction results indicate that the partial substitution of Ru by Mo within the studied level of doping takes place isostructurally in a tetragonal structure (space group P4/mmm) with a solubility up to x = 0.50. Rietlveld- refinement analysis indicates that the Cu-O(2) and Ru-O(3) bond lengths increase with Mo content, while the Cu-O(1) and Ru-O(1) bond lengths, as well as Cu-O(1)-Ru bond angles decrease with increasing x with a minimum at approximately x = 0.30, and then increase for x > 0.30 resulting in inverse bell-type curves. Results of the DC magnetic susceptibility measurements on samples indicate that all samples exhibit ferromagnetic ordering, with T^Curie values depend on Mo content with a dependence that seems to be similar to Cu-O(1)-Ru bond angle. These results suggest a relationship between the structural and magnetic properties in the Ru_1-xMo_xSr₂GdCu₂O₈ system.