Ceramic floor tiles are widely used in buildings. In places where people are bare feet, the thermal sensation of cold or hot depends on the environmental conditions and material properties including its microstructure and crustiness surface. The introduction of the crustiness surface on the ceramic floor tiles interfere in the contact temperature and also it can be an strategy to obtain ceramic tiles more comfortable. In this work, porous ceramic tiles were obtained by pressing an industrial atomized ceramic powder incorporated with refractory raw material (residue from porcelainized stoneware tile polishing) and changing firing temperature. Raw materials and obtained compacted samples were evaluated by chemical analysis, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Thermal (thermal conductivity and effusivity) and physical (porosity) measurements were also evaluated.

In places where people are bare feet, the thermal sensation of cold or hot depends on the environmental conditions and material properties including its microstructure and crustiness surface. The uncomforting can be characterized by heated floor surfaces in external environments which are exposed to sun radiation (swimming polls areas) or by cold floor surfaces in internal environments (bed rooms, path rooms). The property named thermal effusivity which defines the interface temperature when two semi-infinite solids are putted in perfect contact. The introduction of the crustiness surface on the ceramic tiles interferes in the contact temperature and also it can be a strategy to obtain ceramic tiles more comfortable. Materials with low conductivities and densities can be obtained by porous inclusion are due particularly to the processing conditions usually employed. However, the presence of pores generally involves low mechanical strength. This work has the objective to evaluate the thermal comfort of ceramics floor obtained by incorporation of refractory raw materials (residue of the polishing of the porcelanato) in industrial atomized ceramic powder, through the thermal and mechanical properties. The theoretical and experimental results show that the porosity and crustiness surface increases; there is sensitive improvement in the comfort by contact.

O artigo tem o objetivo de aprofundar questões teóricas e conceituais que fundamentam a concepção de sistema de classificação facetada e o tesauro. Apresenta aspectos teóricos referentes aos meios utilizados para organização e recuperação da informação. Os sistemas para organização do conhecimento incluem uma variedade de esquemas para organizar, gerenciar e recuperar a informação, existindo vários tipos de sistemas. Dentre eles, podemos citar sistemas de classificação, tesauro, cabeçalhos de assuntos, ontologia, glossários e dicionários. Descrevem-se princípios, natureza e tipos de sistemas de classificação, com especial ênfase aos sistemas de classificação facetada e o tesauro.

The objective of this article is to contribute to and thoroughly analyze theoretical and conceptual questions which are the base for a conception of faceted classification systems and thesaurus. Theoretical aspects about the means utilized in information organization and retrieval are presented. The systems of knowledge organization include different schemes for organizing, managing and retrieving information.There are different types of systems, for instance, classification system, thesaurus, subject heading, ontology, glossaries and dictionaries. Principles, nature and types of classification systems are described, with special emphasis on the systems of faceted classification and thesaurus.