Measure of the temperature-depth profile by an S band radiometric receiver for biomedical applications

The authors present a method for measuring the temperature-depth profile in a lossy material by applying Kalman algorithm to radiometric signals. The method employs a correlation microwave radiometer. It uses both short-range weighting functions and the delay times of the correlator. An experimental verification of this new thermal inversion approach is presented. The thermal noise is received in the microwave domain, by a S band radiometer by using an automatic experimental bench. A feature of this method is that it can be used in biomedical applications.     

Human gait recognition based on Haralick features

This paper proposes a supervised feature extraction approach that is capable of selecting distinctive features for the recognition of human gait under clothing and carrying conditions, thus improving the recognition performances. The principle of the suggested approach is based on the Haralick features extracted from gait energy image (GEI). These features are extracted locally by dividing vertically or horizontally the GEI locally into two or three equal regions of interest, respectively. RELIEF feature selection algorithm is then employed on the extracted features in order to select only the most relevant features with a minimum redundancy. The proposed method is evaluated on CASIA gait database (Dataset B) under variations of clothing and carrying conditions for different viewing angles, and the experimental results using k-NN classifier have yielded attractive results of up to 80% in terms of highest identification rate at rank-1 when compared to existing and similar state-of-the-art methods.     

Chemical Modification of the Tropical Hardwood Species,Celtis mildbraedii (ESA FUFUO), to Improve its Durability

Celtis mildbraedii (esa fufuo) is a high density hardwood species and abundant in the forest of Ghana. It can be used for construction but is non-durable. In this study, esa fufuo was chemically modified with acetic anhydride (AA) or propionic anhydride (PA) to improve its durability against fungi and termites. Percentage weight loss and visual fungal and termite destruction grades were obtained from a graveyard test conducted for twelve weeks. The modified samples were more durable than the unmodified samples and there was no significant difference in durability between the AA and PA modified samples. The weight loss of the AA and PA modified samples after twelve weeks ground contact were 0.37% and 1.52% respectively, while that of the unmodified samples was 59.10%.     

Numerical study of the thermo-hydrodynamic lubrication phenomena in porous journal bearings

In this work, a numerical simulation is presented for the thermo-hydrodynamic self-lubrication aspect analysis of porous circular journal bearing of finite length with sealed ends. It consists in analyzing the thermal effects on the behavior of circular porous journal bearings. The Reynolds equation of thin viscous films is used taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The presented results are in good agreement with those cited in the literature. The effects of dimensionless permeability parameter and eccentricity ratio on performance parameters are presented and discussed. The results showed that the temperature influence on the journal bearings performance is important in some operating cases, and that a progressive reduction in the pressure distribution, in the load capacity and attitude angle is a consequence of the increasing permeability.     

Hydrogen energy system analysis for residential applications in the southern region of Algeria

The purpose of this paper is related to hydrogen energy system analysis for residential applications in Ghardaia (southern region of Algeria). This system is based on proton exchange membrane fuel cell (PEMFC) technology, which is supplied by fuel reforming process, for producing hydrogen fuel starting from natural gas. The exhaust heat is recovered by a Thermal Storage Tank (TST), which is used in an absorption sub-system as a generator for residential cooling system. The feasibility analysis of an absorption cooling device, using thermal energy of PEMFC sub-system, for a residence application located at the unit of applied research in renewable energy in Ghardaia has been studied and performances were analysed. Electrical and thermal powers generated by the PEMFC sub-system with variable electrical loads (Part Load Ratio) have been analysed. The feasibility study shows that using PEMFC for residential cooling in Ghardaia is a promising solution. It is shown that the temperature of the TST is sufficient to supply the absorption sub-system with a coefficient of performance equals to 0.72 and, the efficiency of the HES equals to 97%.     

Performance analyses of Cu–Cl hydrogen production integrated solar parabolic trough collector system under Algerian climate

The potential of hydrogen production by thermochemical cycle in Algeria using solar radiation as heat sources is estimated under the climate conditions of the country. The study analyzes an integrated copper–chlorine (Cu–Cl) thermochemical cycle with solar parabolic trough system for hydrogen production. In order to determine the most promising solar sites available for deploying the integrated system, the direct normal solar irradiance (DNI) for horizontal tracking system oriented in North-South has been estimated and compared for different locations. Heat gain from parabolic trough collector model is evaluated under Algerian conditions. To describe the different steps of the Cu–Cl cycle for hydrogen production, we perform a thermodynamic analysis accounting for relevant chemical reactions and including the determination of the energy necessary to the cycle. A parametric study is conducted to investigate the effect of heat gain from the parabolic trough collector (PTC) on the hydrogen production rate. Furthermore, the rate production of hydrogen by the Cu–Cl cycle is analyzed and compared for performance improvement of the system for different climatic regions in Algeria. Simulation results reveal great opportunities of hydrogen production using Cu–Cl cycle combined with solar PTC in the south of Algeria with annual hydrogen production exceeds 84 Tons H₂/year (around 0,30 kg/m²/day).