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Aluminosilicate are often produced from kaolin with a kaolin bond in the formulation intended to increase the thermal strength of the product. Because kaolin formulations do not sinter well, investigation of methods for increasing the density of kaolin is highly relevant. The density can be increased by increasing the degree of dispersion. An additive which improves sinterability would be especially effective. Bentonite with its high plasticity and reactive surface meets these requirements to a certain extent. Four formulations of the porcelain tableware were prepared in different percentage from 0 to 15 wt.% of calcic bentonite. The mass loss and shrinkage of different formulations were measured by using the following thermal analysis such as: Differential thermal analysis (DTA), thermal gravimetric analysis (TGA) and dilatometric analysis. Its density, water absorption, total porosity and the flexural strength were also measured at different temperatures between 1250 and 1400°C. It was found that the bentonite added to the formulation increases the strength of the product and reduces the total porosity to 3.35% by increasing the degree of dispersion during the grinding of the components, thereby improving the sintering process of the formulation. On one hand, the weight loss, shrinkage and sintering time were decreased. On the other hand, the thermal resistance and flexural strength were increased at 1380°C for 10 wt.% of bentonite content. Key words: Firing, suspensions, total porosity, thermal properties, flexural strength, bentonite.

Following the tendency of some European countries the briquetiers develop further the aesthetic aspect of their products and, the supply of colors and, aspects of surface will be further extended. The recovery of the sustainability of facades in bricks apparent, the quality of raw materials, and their determination remain a major problem. The presence of soluble salts in the field is fairly harmful for the product terracotta because they are the cause of apparitions of efflorescences. To defeat this type of default our study is on an addition of MgCO3 a mixture of two kinds of clay. The doses MgCO3 were between (0,25‐0,5‐0,75‐1‐1,5%) of the dry mass to treat. With rates of clay yellow and, gray which are respectively (40–60%). In comparison with a previous study where the addition was BaCO3. Finished products obtained with 1% MgCO3 exhibited a better aesthetic aspect, of the qualities insulating, and a mechanical resistance significantly higher than the bricks ceramics ordinary marketed at the present time.

Causes mechanical, thermal, chemical, electrochemical related to the oral environment are effects ranging from simple weathering of biomaterial to the final break, through irreversible deformation, the more invisible and insidious. Study closer to all of these requirements and how to reconcile them is the goal of our work involves the development and analysis of the cements commonly used by dentists and especially cement oxy - zinc phosphate. The powder of zinc phosphate cement is typically made of zinc oxide annealing, alone or mixed with other oxides. The choice and dosage of these oxides must reflect the requirements presented to the concrete (resistance to crushing, shear, acidity, toxicity, solubility, etc .). Thus the formulation of the composition cement needs to have an optimal mix of different components to achieve desired quality cement. Therefore, we limited the number of formulas or mixtures confined to the study of a unique blend of high purity raw materials which we have subjected three regimes of firing at a fixed temperature of 1350° C. The test results show that the cement produced is of very good quality and meets the required standards.

As the term "sustainable development" and the adjective "sustainable" were more and more used in speeches and writings without a clearly defined meaning, it is often a quite weak concept. Our objective is to define this concept as clearly as possible. First we make a historical analysis of the concepts of sustainable development and sustainable, which shows, among other things, that the today related issues are far from being born with the Bruntland report. Then we analyse its main dimensions and their relationships in the literature of the last thirty years. Dimensions and their relationships are very diverse, and above all most of the time not very well defined. In order to be more precise, we try to define precisely these dimensions. It allows us to propose a definition of the concept through 6 prioritized dimensions, able to avoid perverted uses: enlarged economy, social justice, environment, needs and rights, democracy, and long term., L'expression développement durable et l'adjectif durable ont investi les discours et les écrits sans que le sens en ait été clairement défini, ce qui en fait souvent un concept assez vide. Notre objectif est de définir ce concept aussi clairement que possible. Nous faisons tout d'abord une analyse historique des concepts de développement et de développement durable, qui montre notamment que les préoccupations qui y sont liées aujourd'hui sont loin d'être nées avec le rapport Bruntland. Nous analysons ensuite ses principales dimensions et leurs relations dans la littérature de ces trente dernières années. Les dimensions comme leurs relations sont très diverses, et surtout généralement très peu définies. Pour tenter de dépasser cette imprécision, nous cherchons à définir précisément ses dimensions. Cela nous permet de proposer une définition du concept à travers 6 dimensions hiérarchisées, susceptible d'éviter les pervertissements : économie élargie, justice sociale, environnement, besoins et droits, démocratie, et long terme.

In a first step, we define the term indicator: a simplified evaluation or measurement tool, with given quality criteria (representation, operation and policy application). An indicator is always specific to a particular object. Before building or evaluating indicators of environment or sustainable development, we need to define the environment or the concept of sustainable environment in a practical and detailed manner. Then we try to define the environment before analysing some indicators in this field, with particular attention to ecological footprint. Then we analyse and evaluate some indicators of sustainable development: GDP, Human Develoment Index, and a 4-dimension indicator (enlarged economy, social justice, environment, , and long term). The comparison of GDP per inhabitant, Human Develoment Index and 4-dimension indicator of sustainable development in 131 countries, shows that these indicators are evaluating the sustainable development in very diverging ways. The conclusions drawn from indicator usage depend firstly on indicators themselves., Nous définissons tout d'abord ce qu'est un indicateur : un outil simplifié d'évaluation ou de mesure dont nous listons les critères de qualité, qui appartiennent à trois domaines – la représentativité, l'opérationnalité et l'aide à la décision. Un indicateur est en outre toujours spécifique à un objet particulier. Avant de construire ou d'évaluer des indicateurs d'environnement ou de développement durable, il est donc indispensable de définir de manière concrète et détaillée l'environnement ou le concept de développement durable. Nous tentons ensuite de définir l'environnement avant d'étudier quelques indicateurs dans ce champ, avec une attention particulière à l'empreinte écologique. Nous analysons et évaluons ensuite certains des indicateurs existant dans le champ du développement durable : PIB, indice de développement humain, et un indicateur à 4 dimensions (économie élargie, justice sociale, environnement, et long terme). La comparaison pour 131 pays du PIB par habitant, de l'indicateur de développement humain et de l'indicateur de développement durable à 4 dimensions montre que ces indicateurs évaluent l'objet du développement de manière très divergente. Les conclusions tirées de l'usage d'indicateurs dépendent donc d'abord des indicateurs eux-mêmes.