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Effect of Clay Fines on the Behavior of Self-Compacting Concrete

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Engineering（科研） 2013年第2期5卷 213-218页

作者： Zine eddine Abib Haifa Gaher-Abib Fattoum Kharchi 不详

The technology of concrete has significantly increased in recent years through the use of super plasticizer and availability of mineral additions. One of the most recent materials used as an additive, replacing a portion of cement in concrete, is fine clay fired at a temperature of 800℃ to 900℃. This research is based on trials that complied with artificial pozzolan (waste crushed brick), and their effect on the rheological and mechanical behavior of mortar. The addition of 5% of a waste crushed brick has helped not only to improve the strength (tensile and compression), but also to foster a better rheological behavior in terms of fluidity and stability, with a low heat of hydration compared to control. However, tests of optimizing the content of self-compacting concrete (SCC) in coarse aggregates, sand and binder, led us to confirm that the combined mass of more optimal (better workability and stability) is that based on low in volumetric percentage of sand/paste with a granular skeleton richest gravel low dimensions (2/3 of G 3/8 and 1/3 of G 8/15).

关键词： Waste Crushed Brick Pozzolanic Activity Heat of Hydration Workability Strength Self Compacting Concrete

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溶于天然水中的氦、氖、氩的简化分析

地质地球化学 1989年第4期17卷 63-66页

作者： Ryuichi Sugisaki Kiyoko taki 张盛南京大学外国教材中心

本文提出了溶于天然水中氦、氖、氩的简化分析方法。简化分析方法的原理是利用气相色谱法分析与水样处于溶解平衡的气相中所含的稀有气体。这种方法不需要任何真空系统或复杂的流程。该方法适用于分析溶于水中的任何种类的气体,对氦的... 详细信息

本文提出了溶于天然水中氦、氖、氩的简化分析方法。简化分析方法的原理是利用气相色谱法分析与水样处于溶解平衡的气相中所含的稀有气体。这种方法不需要任何真空系统或复杂的流程。该方法适用于分析溶于水中的任何种类的气体,对氦的常规分析也是有用的,因为这种简化方法的灵敏度很高,故可用来测定含量低达50ppb的氦,即溶解在与空气保持平衡的水中的氦总量。

关键词：天然水氦氖氩

Study of Thermal Conductivity of Porous Silicon Using the Micro-Raman Method

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Open Journal of Physical Chemistry 2012年第1期2卷 1-6页

作者： Amaria Ould-Abbas Mama Bouchaour Nasr-eddine Chabane Sari Research Unit Materials and Renewable Energy (RUMRE) University of Abou Bekr BELKAID of Tlemcen Tlemcen Algeria

In this work, we are interesting in the measurement of thermal conductivity (on the surface and in-depth) of Porous silicon by the micro-Raman spectroscopy. This direct method (micro-Raman spectroscopy) enabled us to develop a systematic means of investigation of the morphology and the thermal conductivity of Porous silicon oxidized or no. The thermal conductivity is studied according to the parameters of anodization and fraction of silicon oxidized. Thermal transport in the porous silicon layers is limited by its porous nature and the blocking of transport in the silicon skeleton what supports its use in the thermal sensors.

关键词： Mono-Crystal Silicon Porous Silicon Thermal Conductivity Micro-Raman Spectroscopy

GIS, Forest Fire Prevention and Risk Matrix in the National Forest of Khoudida, Sidi Bel Abbes, Algeria

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Open Journal of Ecology 2020年第6期10卷 356-369页

作者： Mayssara El Bouhissi Salah eddine Bachir Bouidjra Khé loufi Benabdeli Laboratoire Ecodé veloppement des espaces Universit&#233 Djillali Liabes de Sidi Bel Abbes Sidi Bel Abbes Algeria Laboratoire Gé o-Environnement Universit&#233 Stambouli de Mascara Mascara Algeria

Forest fires in Algeria are ravaging an average of more than 32,000 hectares annually despite the prevention and control plan put in place. They are the most damaging factor of degradation of the forest and weigh heavily on the environment and the local economy. Conventional methods for fire prevention and control are time consuming and are not always reliable in view of the complexity and diversity of forest ecosystems. The main idea behind this study is to use the GIS and remote sensing for the development of a fire risk map of the Khoudida State Forest (Algeria). The approach adopted involves three parameters that control the fire behavior, which are: the top-morphology of the field, the combustibility of the plant cover and hazards. For each factor its correlation with risk was evaluated;the combination of the slope, altitude and exposure parameters in the topo-morphological index and the hazard map made it possible to evaluate the average risk for an area of more than 2132 hectares, 1521 hectares high and only 493 hectares, respectively 51.4%, 36.7% and 11.9%.

关键词： Fire GIS Remote Sensing Vulnerability Forest Hazard Khoudida Risk

Crystallization Kinetics and Magnetic Properties of Fe40Ni40B20Bulk Metallic Glass

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Advances in Chemical Engineering and Science 2014年第1期4卷 36-38页

作者： Nasr-eddine Chakri Badis Bendjemil M. Baricco LASEA Department of Chemistry University of Badji Mokhtar Annaba Algeria LASEA Department of Chemistry University of Badji Mokhtar Annaba Algeria University of 08 mai 1945 Guelma Guelma Algeria Università di Torino Via P. Giuria 9 Torino Italy Università di Torino Via P. Giuria 9 Torino Italy

Fe-based bulk metallic glasses (BMGs) have been extensively studied due to their potential technological applications and their interesting physical properties such as a low modulus of elasticity, high yielding stress and good magnetic properties. In the present work, the bulk metallic glass (BMG) formation of Fe40Ni40B20 (numbers indicate at %) with a ribbon form was fabricated by the single roller melt-spinning method. Rapid solidification leads to a fully amorphous structure for all compositions. The thermal properties associated with crystallization temperature of the glassy samples were measured using differential scanning calorimetry (DSC) at a heating rate of 10℃/mn. The microstructure and constituent phase of the alloy composite have been analyzed by using X-ray diffractometry (XRD). The effect of high temperature on the isothermal crystallization of Fe40Ni40B20 ribbon was investigated by HTX-ray diffraction. In addition, these ribbon glasses also exhibit good soft magnetic properties with M-H curvature measured under the magnetic fields between –1 kOe and 1 kOe.

关键词： Bulk Metallic Glasses DSC XRD Method HTX Magnetic Properties

The Mechanical Properties of the System and Training Zr59Nb5Cu18Ni8AL10 Bulk Metallic Glasses

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Advances in Chemical Engineering and Science 2013年第4期3卷 274-277页

作者： Nasr-eddine Chakri Badis Bendjemil M. Baricco LASEA Department of Physic University of Badji Mokhtar Annaba Algeria

In the present work, the glass formation of Zr59Nb5Cu18Ni8Al10 (numbers indicate at %) alloy with diameter of 2 mm was prepared through water-cooled copper mold casting and in a ribbon form by the single roller melt-spinning method. This study is primarily devoted to evaluating the results obtained with the two methods of the development. The thermal stability was evaluated by differential scanning calorimetry (DSC) at a heating rate of 10℃/mn. The characteristic data of the bulk metallic glass are presented, including glass transition temperature (Tg) and crystallization temperature (Tx). The microstructure and constituent phases of the alloy composite have been analyzed by using X-ray diffraction, and observed by Scanning Electron Microscopy (SEM). The mechanical properties of bulk Zr59Nb5Cu18Ni8Al10 were alloy measured by compression tests at room temperature.

关键词： Ribbon and Bulk Metallic Glasses Amorphous Fracture Morphology Mechanical Properties

Effect of the Number and Orientation of Fractures on the P-Wave Velocity Diminution: Application on the Building Stones of the Rabat Area (Morocco)

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Geomaterials 2013年第3期3卷 71-81页

作者： Hamid El Azhari Iz-eddine El Amrani El Hassani Université Mohammed V-Agdal (Maroc) Faculté des Sciences Département de Géologie Rabat Morocco Université Mohammed V-Agdal (Maroc) Institut Scientifique Département des Sciences de la Terre Equipe de Géomatériaux et Géo-Environnement (GeoM&E) Rabat Morocco

This study is focused on two types of Moroccan rocks, among the most widely used as building stones: the calcarenite of Salé (CS) and the marble of oued Akrech (MA). The two rocks, lithologically different, show a clear contrast of their P-wave velocities (Vp): 3.90 vs 5.10 km/s at dry state and 4.29 vs 5.64 km/s at saturation. The “Artificial fractures” created in the two rock types reveal that their Vp undergo diminutions which the rates vary depending of the number and the plane orientation of the fractures. In the CS, Vp shows an increasing of cumulative diminution (Dc) according to the number of fractures, but with a variable rate of unitary diminution (Du) from one fracture to the other. This defines a linear regression with a low coefficient of determination (Dc = 10.18NbFr + 10.96;r2 = 0.87). The mode of the Vp evolution would be related to the roughness of fractures surface, which itself depends upon the petrographic nature of the calcarenite (friable structure, high porosity and heterogenous composition). The MA manifested an increasing Dc with a fairly constant rate of Du from a fracture to another, giving a regression line with a high coefficient of determination (Dc = 12.17NbFr – 10.69;r2 = 0.99). This steady diminution of Vp would be related to the granoblastic texture and the monomineral composition of the marble, which engender smoother fracture surfaces. The rates of Vp diminution also depend on the orientation plane of the fractures relative to the direction of wave propagation. The fractures parallel (θ = 0°) amplify slightly the Vp, playing a significant role of “waveguide”. The fractures oriented at 45° lead to a diminution lower than those of fractures oriented at 25° and 90°. The same trend of diminution, but at variable rates, appears on the samples of the two types of stones at dry and saturated state. This can be explained by the compressive nature of P-waves, which obey the physic laws of the transmission of the constraints in the solid me

关键词： Fracture Diminution P-Wave Velocity Calcarenite Marble Morocco

Synthesis of Ti3SiC2-Bicarbide Based Ceramic by Electro-Thermal Explosion

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Advances in Chemical Engineering and Science 2014年第2期4卷 242-249页

作者： Nasr-eddine Chakri Zoubida Habes Abdelaziz Toubal Badis Bendjemil 1Physic Department Badji-Mokhtar University Annaba Algeria 2Laboratory Environmentally Security and Alimentary (LASEA) Badji-Mokhtar University Annaba Algeria Laboratory Environmentally Security and Alimentary (LASEA) Badji-Mokhtar University Annaba Algeria Physic Department Badji-Mokhtar University Annaba Algeria

A polycrystalline dense Ti3SiC2 based ceramic material has been produced by several techniques. The effect of addition of TiC and SiC is also studied. The Ti3SiC2 material shows extraordinary electrical, thermal and mechanical properties. Furthermore, it shows a damage tolerance capability and oxidation resistance. In this work, we have synthesized Ti3SiC2 by electro-thermal explosion chemical reaction (ETE) with high current density (900 Amperes/a.u) followed by uniaxial pressure. The structural properties of the as-prepared materials are studied by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX) techniques. The chemical cartography, imaging and electronic properties are investigated using Ultra-STEM and electron high energy loss resolution spectroscopy (EELS) techniques, respectively. The surface of Ti3SiC2 is characterized by means of X-ray photoelectron spectroscopy (XPS). High resolution C 1s, Si 2p, Ti 2p, Ti 3s core level spectra are explained in terms of crystallographic and electronic structure. Valence band spectrum is performed to confirm the validity of the theoretical calculations.

关键词： Ti3SiC2 Based Ceramic Intermetallic Bicarbide Electro-Thermal Explosion Reaction (ETE) Valence Band Spectra Core Level Excitation

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被动测量的网络障排除和测试

被动测量的网络障排除和测试

作者： AMIR-eddine YOUSSOUF MADI（爱丁）中南大学

学位级别：硕士

随着网络普及,安全以及需要确保在大规模的网络数据传输技术的进步越来越快是高效完成不可或缺的。许多公司和运营商都在网络上传输重要的信息,但没有数据泄漏是不能容忍的。本文讨论了鉴定和解决在使用被动网络测量一个特定的网络泄漏... 详细信息

随着网络普及,安全以及需要确保在大规模的网络数据传输技术的进步越来越快是高效完成不可或缺的。许多公司和运营商都在网络上传输重要的信息,但没有数据泄漏是不能容忍的。本文讨论了鉴定和解决在使用被动网络测量一个特定的网络泄漏问题。目前,被动监测的基本测量方法并没有改变,只有链接速度和技术已经更新了。通过使用家用计算机来做端到端的测量,可以使测量更加容易。用这个修改后的方法来测量,检测变得更容易,更可靠,而且只需要采集少量的数据。网络故障排除并不需要问题原因查找,是因为故障是随机发生的。 “小企业网”的排斥模型部分地被用于寻找问题的原因。故障排除的特定模型不应该是自我为目的,最重要的是解决问题的原因。但是,必须知道不仅仅只有一个适当的模型或模式组合能适合每个案例。此外,如果问题很小,通过直觉去找问题的原因是明智的,而不使用任何模型。这些模型的价值增长是随问题和案件的增大而变得更加复杂。最大的问题仍然在与时间相关的多点测量：具有成本效益的电脑准确的时钟同步方法的可用性。此外,从链路数据采集速度可达1 Gbit/s时,仍是一个问题。被动监测的数据包是一个测试网络设备故障排除和强大的方式。

关键词：被动网络测量流量测量数据包捕获