Magnetization studies in amorphous Co80-x Gdx B20

We have studied amorphous Co80-x Gdx B20 alloys prepared by melt spinning technique. The Gd moment at 4.2 K is found to be 7 µB which agrees with the theoretical value indicating a collinear spin structure. The magnetic compensation at 4.2 K occurs for x close to 10.3. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Co-Gd atom pairs have also been evaluated.We have studied amorphous Co80-x Gdx B20 alloys prepared by melt spinning technique. The Gd moment at 4.2 K is found to be 7 µB which agrees with the theoretical value indicating a collinear spin structure. The magnetic compensation at 4.2 K occurs for x close to 10.3. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Co-Gd atom pairs have also been evaluated

3D Model Simulating the Hydro-mechanical State of Unsaturated and Deformable Material during Hot air Drying

A three dimensional model to predict the hydro-mechanical state of unsaturated and deformable material during hot air drying has been proposed. The material viscoelastic behaviour was formulated using Bishop’s effective stress theory for partially saturated material using the liquid saturation as the Bishop parameter. The hydro-thermal and mechanical equations were coupled by the fluid pressure and the solid matter velocity. The model was applied to a deformable material (innovative clay-cellulose fibers composite) subjected to convective drying. A generalized Maxwell model with five elements, whose parameters were measured experimentally and correlated to water content was used to describe the material’s viscoelastic behavior. The hydro-thermal part of the proposed model was validated on the basis of a comparison of experimental and simulated drying rate curves. The Von Mises stress was simulated and compared to the experimental tensile strength in order to predict the time and the region of material failure. For a drying process at 95°C, the region of failure risk was identified. The failure may occur on the lateral surface of the slab in contact with air at a drying time of 2.5h

Perception of change and ethical issues in the use of information and communication technologies in the health sector: Results of an online survey

For several decades, information and communication technologies (ICT) applied to health have undergone a revolutionary development, whether they are e-health, telemedicine or others, these digital changes have marked the global care system. Today, internet is the common source of information to many uses, and it is considered as the wealthiest mine of information for any kind including those of health. This survey, which interviews both Moroccan practitioners and users, is conducted online by distributing two questionnaires. The aim of this study is to discover the perception that Moroccan doctors and users have concerning the change ICTs have been able to bring about without neglecting the ethical and deontological issues involved. The results showed that doctors are already using the web in their daily practice and are open to eHealth practices such as telemedicine. As for users, the practices of eHealth are an asset that should become more widespread. Further research is needed to confirm and further explore the results of this study

Design of a Low-cost and Compact Radiometer for Spectral Acquisition of Vegetation and Bare Soil

We describe, in this article, the design of a low-cost and compact radiometer with five analog channels for spectral acquisition: four in the visible (blue, green, red and panchromatic) and one channel in the near-infrared. This small embedded system is based on an 8-bit microcontroller for automatic data acquisition, calibrating, storing and serial link processing with a compatible PC, through a C++ application software provided to handle and deal with the mass of data collected and stored in an EEPROM. The acquisition of spectral reflectance measurements of an object for different wavelengths allows the construction of a characteristic curve, named spectral signature of the object. The study of the spectral signatures of different types of surfaces such as water, bare ground or vegetation allows their identification in remote sensing image processing, and consequently, facilitates the interpretation of this kind of data, as, for instance, the AVHRR data of the HRPT images acquired and freely distributed by the satellite NOAA

Experimental Study on the Thermal Behavior of Building Materials in A Dry and Arid Climate

This paper analyzes the performance of material constructions in two small cubicle rooms during hot and cold periods, based on the results of experiments conducted at the University of Ouargla in southeastern Algeria. The climatic conditions in this region are extreme. The outdoor ambient temperature varies between 47 C° during the day and 30 C° at night for the hot period, and between 16 C° during the day and -1 C° at night for the cold period. The rooms of the in-situ cubicles were identical with a dimension of 1 m × 1 m × 1 m. The walls of the stone cubicles were made with Ouargla stone (15 cm) and two layers of gypsum (1.5 cm), and for brick, the walls of the cubicles were made with hollow brick (15 cm) and two layers of mortar (1.5 cm). Measurements are made of ambient temperatures, wall temperatures, and instantaneous heat flux densities through the walls. The effect of building material selection on energy consumption was also studied. During two different periods (August 28-30, 2020) and (October 21-23, 2020), the construction with stone decreased the indoor temperature by approximately 6 °C during the day and reduced the apparent thermal mass of the room in the first period, but in the second period, the indoor temperature increased by approximately 1 °C. The residential scale confirmed that Ouargla stone improves thermal comfort by providing high insulation and reducing indoor temperature oscillations. This material is abundant in nature and can be easily extracted and used directly in constructing houses without recycling it, which helps reduce CO2 emissions. &nbsp

Qualification multi-critères des gammes d'usinage : application aux pièces de structure aéronautique en alliage Airware®

The optimization of machining sequences is not easy because it suffers from two major shortcomings. The first focuses on the adaptability of existing ranges to current production facilities and their evolution over the years to respond to technological developments. The second point concerns the lack of consideration in the mechanical behavior of the part during the development of machining sequence. This thesis addresses these in relation to the FUI OFELIA project. At first, they study the influence of the machining parameters on the deformation of the workpiece. The aim is to predict the mechanical behavior of the part to identify recommendations with minimal distortion. The second issue deals with multi-criteria evaluation of manufacturing ranges. The criteria take into account are the deformation of the workpiece, productivity through a quick estimate of machining time and recyclability of chips produced during machining. On the other hand, we propose a geometric model of the intermediate states of the workpiece during machining in order to both assess the manufacturing recommendations and to drive the simulation calculations of the deformation of the workpiece during machining.L’optimisation des gammes d'usinage n’est pas aisée, car elle souffre de deux lacunes importantes. La première est axée sur l'adaptabilité des gammes existantes aux moyens actuels de production et à leurs évolutions au fil des années pour répondre aux évolutions technologiques. Le second point concerne, l’absence de prise en compte du comportement mécanique de la pièce durant l'usinage dans l'élaboration de la gamme. Ces travaux de thèse abordent ces problématiques dans le cadre du projet FUI OFELIA. Ils étudient, dans un premier temps l'influence de la gamme d’usinage sur la déformation de la pièce. L'objectif est de pouvoir prédire le comportement mécanique de la pièce pour identifier les gammes minimisant les déformations. Le second point s'intéresse à l’évaluation multicritères des gammes de fabrication. Les critères retenus prennent en compte la déformation de la pièce, la productivité à travers une estimation rapide des temps d'usinage et la recyclabilité des copeaux obtenus lors de l'usinage. D’autre part, nous proposons un modèle géométrique des états intermédiaires de la pièce durant l’usinage pour à la fois évaluer les gammes de fabrication et conduire les calculs de simulation de la déformation de la pièce durant l’usinage

Co distribution in ferromagnetic rutile Co-doped TiO2_2 thin films grown by laser ablation on silicon substrates

Pure rutile Co-doped TiO$_2$ films were fabricated successfully by the conventional pulsed laser deposition technique on silicon substrates from a ceramic target. Under the right fabrication conditions, Co concentration in the films could be almost the same as in the synthesized target, and films under various conditions all are ferromagnetic well above room temperature. Even though Rutherford backscattering spectroscopy measurements show that Co atoms seem to be mostly localized near the surface of the films and less exist in deeper levels, other experimental evidences show that the ferromagnetism does not come from Co segregations but from the Co-doped TiO$_2$ matrix. Rutile Ti$_1-x$Co$_x$O$_2$ thin films grown by a very simple technique on low-price silicon substrates showing Curie temperature (TC) above 400 K appear to be very attractive to applications.Comment: 1 file, 13 pages, 4 figures. to be published in Appl. Phys. Lett. (2003

Design of a Low-cost and Compact Radiometer for Spectral Acquisition of Vegetation and Bare Soil

We describe, in this article, the design of a low-cost and compact radiometer with five analog channels for spectral acquisition: four in the visible (blue, green, red and panchromatic) and one channel in the near-infrared. This small embedded system is based on an 8-bit microcontroller for automatic data acquisition, calibrating, storing and serial link processing with a compatible PC, through a C++ application software provided to handle and deal with the mass of data collected and stored in an EEPROM. The acquisition of spectral reflectance measurements of an object for different wavelengths allows the construction of a characteristic curve, named spectral signature of the object. The study of the spectral signatures of different types of surfaces such as water, bare ground or vegetation allows their identification in remote sensing image processing, and consequently, facilitates the interpretation of this kind of data, as, for instance, the AVHRR data of the HRPT images acquired and freely distributed by the satellite NOAA

An interactive approach for solar energy system: design and manufacturing

The energy production in the word is a very complex problem with decreasing the pollution. Therefore, the aim is to find an optimal solution, this research focuses on the development and the optimization of parabolic concentrator using an interactivity approach and virtual design tools. Recently, several works have been developed in this area. In this study, a new conception, design Optimization approach has been involved in system energy design including new concept. The design strategy has been successfully applied to design problems. The optimizer tool developed for based on Heuristic: Gravitational Search Algorithm. The results of the presented in this paper are significant in the system energy design, which presents an effective approach of development by reducing the cost of installation, the time of analysis by increasing the radiation and solar flux concentrated within the parabola generating an increase in accumulated energy

Drying parameters influence on ‘Ameclyae’ Opuntia ficus prickly pear oil quality

[EN] The aim of this work is to study the effects of drying conditions on the quality of extracted pricly pear seed oil, specifically α-tocopherol content. Drying experiments were carried on following a full 23 factorial design using a vertical drying tunnel. The temperature range was 45 to 70°C, relative humidity range was 15 - 30% and air velocity was 1 and 2 m/s. The Midilli-Kucuk model was found with satisfaction describing the seed air drying curves with a correlation coefficient of 0.999 and a standard error of 0.01. For each drying condition, the extraction of fixed oil seeds was performed at cold using mechanical pressing method. The oil quality was evaluated on the basis of the a-tocopherol content. The a-tocopherol was identified and quantified by high-performance liquid chromatography (HPLC-UV). According to the experimental results, it was found that convective drying of thin layer of seeds at soft air conditions, drying temperature of 45°C, relative humidity of 15% and air velocity of 1m/s give the optimal quality of extracted oil in terms of a-tocopherol content.Hassini, L.; Desmorieux, H. (2018). Drying parameters influence on ‘Ameclyae’ Opuntia ficus prickly pear oil quality. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 115-122. https://doi.org/10.4995/IDS2018.2018.7861OCS11512