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8 results on '"Bensaoula, Abdelhak"'

1. Building Airflow Monitoring and Control using Wireless Sensor Networks for Smart Grid Application

Author

Khalil, Nacer, Benhaddou, Driss, Bensaoula, Abdelhak, Burriello, Michael, and Cline Jr, Raymond E

Subjects
Computer Science - Systems and Control
Abstract

The electricity grid is crucial to our lives. House- holds and institutions count on it. In recent years, the sources of energy have become less and less available and they are driving the price of electricity higher and higher. It has been estimated that 40% of power is spent in residential and institutional buildings. Most of this power is absorbed by space cooling and heating. In modern buildings, the HVAC (heating, ventilation, and air conditioning) system is centralised and operated by a department usually called the central plant. The central plant produces chilled water and steam that is then consumed by the building AHUs (Air Handling Units) to maintain the buildings at a comfortable temperature. However, the heating and cooling model does not take into account human occupancy. The AHU within the building distributes air according to the design parameters of the building ignoring the occupancy. As a matter of fact, there is a potential for optimization lowering consumption to utilize energy efficiently and also to be able to adapt to the changing cost of energy in a micro-grid environment. This system makes it possible to reduce the consumption when needed minimizing impact on the consumer. In this study, we will show, through a set of studies conducted at the University of Houston, that there is a potential for energy conservation and efficiency in both the buildings and the central plant. We also present a strategy that can be undertaken to meet this goal. This strategy, airflow monitoring and control, is tested in a software simulation and the results are presented. This system enables the user to control and monitor the temperature in the individual rooms according the locals needs., Comment: SAAEI 2014

Published
2016

3. Influence of HiPIMS pulse widths on the deposition behaviour and properties of CuAgZr compositionally graded films

Author

Lapeyre, L., Wieczerzak, K., Hain, Caroline, Metzger, J., Sharma, A., Bensaoula, Abdelhak, Michler, J., and Nelis, Thomas

Subjects
QC Physics, Materials Chemistry, Surfaces and Interfaces, General Chemistry, Condensed Matter Physics, Surfaces, Coatings and Films
Abstract

In this work, the influence of different pulse widths (25, 50 and 100 μs) during high power impulse magnetron sputtering (HiPIMS) of copper, silver and zirconium was investigated in terms of plasma properties and properties of combinatorial composition gradient CuAgZr film libraries. In situ plasma diagnostics via optical emission spectroscopy (OES), time-of-flight mass spectrometry (TOFMS), and modified quartz crystal microbalance (m-QCM), followed by film ex situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) investigations allowed to determine the effect of deposition parameters on the thin films' microstructural changes. Changing the pulse width, while keeping the duty cycle constant, modified the discharge composition in the target region and the ionised fraction of the sputtered species in the substrate region. The maximum Cu ionised fraction (19 %) was found for 50 μs, resulting in compact and smooth morphology for Cu-rich films, whereas short 25 μs pulses provided porous columnar films with rough surfaces, as the result from Ar+ bombardment. For Ag-rich films, Ag segregation allowed the deposition of dense layers, regardless of the used pulse width. Furthermore, low Ag (

Published
2022

4. The use of multilayer neural networks in material synthesis

Author

Bensaoula, Abdelhak, Malki, Heidar A., and Kwari, A. Marcellino

Subjects
Neural networks -- Usage, Semiconductors, Thin films -- Production processes, Business, Computers, Electronics, Electronics and electrical industries
Abstract

This paper demonstrates the incorporation of a multilayer neural network in semiconductor thin film deposition processes. As a first step toward neural network-based process control, we present results from neural network pattern classification and beam analysis of reflection high energy electron diffraction RHEED images of GaAs/AlGaAs crystal surfaces during molecular beam epitaxy growth. For beam analysis, we used the neural network to detect and measure the intensity of the RHEED beam spots during the growth process and, through Fourier transformation, determined the thin film deposition rate. The neural network RHEED pattern classification and intensity analysis capability allows, powerful in situ real time monitoring of epitaxial thin film deposition processes. Our results show that a three layer network with sixteen hidden neurons and three output neurons had the highest correct classification rate with a success rate of 100% during testing and training on 13 examples. Index Terms - Epitaxy, growth rate, image classification, neural networks, process control, RHEED.

Published
1998

8. Tunable TiO2 (anatase and rutile) materials manufactured by mechanical means

Author

Savio, Amal K.P.D., Starikov, David, Bensaoula, Abdelhak, Pillai, Rajeev, de la Torre García, Luis L., and Robles Hernández, Francisco C.

Subjects
*TITANIUM dioxide, *PHOTOCATALYSIS, *ELECTRIC properties of metals, *ULTRAVIOLET radiation, *BAND gaps, *COST effectiveness, *X-ray diffraction
Abstract

Abstract: Anatase and rutile are two naturally found titanium dioxide phases with attractive dielectric, catalytic, and photo-catalytic characteristics. Anatase and rutile are photo-catalytically active in the UV region, since their band gaps are 3.2eV and 3.75eV, respectively. In this work is proposed a cost-effective, easy to launch methodology for modification of the TiO2 bandgap. Such modifications will make the oxides photo-catalytically active in a wider optical range from the visible wavelengths to an extended UV spectrum. The proposed methodology is based on mechanical means such as mixing and milling. Various ratios of anatase:rutile were investigated and milled from 0 (mixing only) to 50h using high energy mills. The results on mixing and milling show that it is possible to modify the bandgap of the TiO2 from 2.53eV to 4.04eV. The characterization was conducted by means of X-ray diffraction, Raman spectroscopy, Scanning electron microscopy, and optical spectroscopy. [Copyright &y& Elsevier]

Published
2012
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