INFLUENCE OF BOILING TEMPERATURE ON THE PANELS LVL (LAMINATED VENEER LUMBER) QUALITY MADE WITH OAK (CANARIENSIS) ALGERIA WOOD

The panels LVL (Laminated Veneer Lumber) are less used in construction, which are produced by peeling trunk of trees, undergone baking operation which one determined the quality of plating and LVL panels made by gluing. Our study here consist to vary the boiling temperatures ranging from 40C°, 50 C°, 60 C°, to 70 C° (two panels are drawn for each temperature, and 14 specimens (20 * 20 * 336mm) for each panels) that was secure settings peeling, speed of rotation of the lathe, pressure bar, clearance angle of the knife and the thickness of the veneer, as we fix the amount of glue 400g / cm2, the pressure pressing the panels in order to clearly identify the influence of baking temperature logs of Algerian oak wood quality. Our controls are carried out by non-destructive testing after that the specimens are tested with destructive method under four point bending, according to the perpendicular direction and parallel plating, and we took into consideration the calculation of Young's modulus and stress at break for each series of panels

INCLUSIVE STAKEHOLDERS APPROACH: BASIS FOR ACCEPTABLE AND SUSTAINABLE INDUSTRIAL RELATIONS ENVIRONMENT IN NIGERIA

The paper highlights some of the several reforms put in place by the present Civilian administration. It tagged the administration, reforms regime. It contends that several of reforms have far reaching implications for the practice of industrial relations in Nigeria. It observes that the authors of the reforms assume away the impacts of these reforms on the various stakeholders in industrial relations in Nigeria. It highlights the dangers that are already rearing their ugly head as far as industrial relations practice is concerned. It proposes an inclusive stakeholders approach as way of promoting an acceptable and sustainable industrial relations environment in the reform regime. It contends that with this approach organizations or business firms have to be fair, accountable, responsible and transparent towards all stakeholders of the organizations or firms. It notes that the institutional landscapes from which the reforms were adopted for implementation in Nigeria differ considerably and this calls for some inbuilt strategy for sustainability of acceptable industrial relations practice

EXTENDING GENSTAT CAPABILITY TO ANALYZE RAINFALL DATA USING MARKOV CHAIN MODEL

Rainfall is of critical importance for many people particularly those whose livelihoods are dependent on rain fed agriculture. Methods of analysis of daily rainfall records based on Markov chain models have been available for many years and their value is widely recognized. However they are rarely used because of the complexity of their analysis. This paper describes how these models are being made more accessible through a series of specially written procedures and menus in GenStat, a widely available statistics package

Couches minces dures type Cr-Al-N pour outils de coupe du bois

Les outils de coupe pour l’usinage métallique sont très développés ces dernières années, ainsi plus 90% des outils en carbure et 10% des forets, tarauds en acier sont revêtus, tout en donnant des résultats intéressants, malheureusement cette tendance n’existe pas en usinage bois. Ce travail donc a pour objectif de développer des outils revêtus pour les tester en défonçage du bois de Pin d’Alep une essence très répandues dans le bassin méditerranéen. Notre étude se fera sur des outils de coupe en carbure revêtu en couches minces de CrN et de CrAlN à différent pourcentage respectivement d’Al déposé grâce à un bâti magnétron de marque Nordiko 3500.Les conditions de dépôts sont optimisés lors des précédents travaux, les essais d’usinage sont réalisés sur une défonceuse à commande numérique de marque Recordi. Le comportement à l’usure des outils modifiés est avéré très prometteur, on a constaté que les films en nitrure de chrome résistent d’une manière considérable par rapport aux outils en carbures. L’ajout de l’Aluminium n’améliore pas la résistance à l’usure mais contribue à la cristallisation des films

Détermination de la résistance à la propagation de fissures d’essences de bois Algériens

72 p. : ill. ; 30 cmLe bois est l’un des matériaux de construction les plus répandus, qui présente des défauts comme les noeuds, les poches de résine, les fissures dûs au séchage. Leurs présence dans une structure en bois est la conséquence première d’une structure exposée aux contraintes extérieurs et l’amorçage du défaut, tout en recevant une énergie extérieure suffisante pour faire propager le défaut en créant des nouvelles surfaces dans la structure en bois. En ce qui concerne les éléments structuraux en bois. Dans notre travail, on a déterminé un facteur intrinsèque à la rupture, qui est le taux de restitution de l’énergie G (J/m2), caractérisant la résistance à la propagation des fissures, de trois essences de bois Algérien, à partir d’éprouvettes normalisées sur lesquelles sont prévues des entailles. Ces dernières ont subit des essais de flexion trois points. L’exploitation des résultats obtenus nous permet d’estimer le taux de restitution de l’énergi

Caractérisation et valorisation des bois de chêne en vue d'une utilisation dans le secteur de la construction

183 p. : ill. ; 30 cmLes chênes Algériens représentent une ressource forestière importante mais constituée essentiellement de bois de diamètre réduit est souvent mal conformes. Parallèlement l'outil industriel du secteur bois en Algérie étant dédié à la transformation de bois importés d'Europe ou d'Afrique centrale, n'est pas adapté à la transformation des bois locaux. Par cette thèse nous voulons faire une étude fine de la typologie de la ressource de chênes Algériens, afin d'évaluer ses caractéristiques physiques et mécaniques, ainsi que leurs possibilité de transformation industriel par déroulage, qui offre des perspectives de recherche appliquée focaliser sur possible exploitation des ressources forestières disponible localement, ce qui va générer une activité au niveau des localités forestières donnant ainsi des débouchés à cette espèce disponible, notamment dans le secteur de la construction qu'est en plein essor en Algérie, qui incite à l'utilisation accrue de bois dans les différents projet

Multi-objective H 2 /H ∞ saturated non-PDC static output feedback control for path tracking of autonomous vehicle

International audienceThis paper presents a new fuzzy output feedback control design for autonomous vehicle steering under actuator saturation, unavailability of the sideslip angle measurement, unknown road curvature, and lateral wind force. To take into account the actuator constraint, the saturation effect is transformed into dead-zone nonlinearity. A static output controller based on non-compensation parallel distributed technic and a Takagi-Sugeno (T-S) model of vehicle lateral dynamics is proposed to consider the unavailability of some vehicle states. To avoid the problem of imposing bounds on membership functions time derivatives resulting from the use of the fuzzy Lyapunov approach, a proper integral structure based on the non-quadratic Lyapunov approach is investigated. The mixed [Formula: see text] stabilization conditions of the augmented closed-loop system are expressed in terms of linear matrix inequalities (LMIs). Finally, the robustness and the advantages of the proposed approaches are demonstrated through different tests

Adaptive fuzzy observer based non-quadratic control for nonlinear system subject to actuator faults and saturation

International audienceThis paper provides a new non-quadratic stabilization conditions based on adaptive fuzzy observer for a class of Takagi-Sugeno (T-S) fuzzy systems subject to external disturbances and both actuator faults and saturation. Firstly, an observer based fault tolerant control (FTC) is proposed, not only to estimate both system states and actuator faults but also to compensate for the actuator faults and to stabilize the faulty system with input constraints. The saturation effect is transformed into dead-zone nonlinearity and the generalized sector bound condition is used to estimate the attraction domain. To less the conservatism of the quadratic Lyapunov technique, a proper integral structure based on the non-quadratic function is investigated. The H∞ criteria is considered and the robust stabilization conditions of the faulty closed-loop system are expressed as a linear matrix inequalities (LMIs) optimization problem. Finally, the robustness and the advantages of the proposed approach are demonstrated through a mixed CSTR and a numerical example

Mechanical and durability properties of concrete incorporating glass and plastic waste

The main objective of this work is to contribute to the valorization of plastic and glass waste in the improvement of concrete properties. Waste glass after grinding was used as a partial replacement of the cement with a percentage of 15%. The plastic waste was cut and introduced as fibers with 1% by the total volume of the mixture. Mechanical and durability tests were conducted for various mixtures of concrete as compressive and flexural strengths, water absorption, ultrasonic pulse velocity, and acid attack. Also, other in-depth analyses were performed on samples of each variant such as X-ray diffraction (XRD), thermogravimetric analysis (DSC-TGA), and scanning electron microscope (SEM). The results show that the addition of glass powder or plastic fibers or a combination of both in concrete improved in the compression and flexural strengths in the long term. The highest compressive strength was obtained in the mix which combines the two wastes about 26.72% of increase compared to the control concrete. The flexural strength increased in the mixture containing the glass powder. Therefore, the mixture with two wastes exhibits better resistance to aggressive sulfuric acid attack, and incorporating glass powder improves the ultrasonic pulse velocity