Mineralogical characterization of clays used in the structural ceramic industry in west of S. Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physical and mechanical properties of ceramics from clays of the west of S. Paulo State, Brazil

Argilas de interesse da indústria de cerâmica estrutural foram caracterizadas. Algumas propriedades físicas de diversas massas cerâmicas, preparadas a partir de material coletado em depósitos artificiais, também foram analisadas. Todas as massas investigadas exibem alta concentração de componentes finos (< 2 mim) e considerável grau de plasticidade, o que é compatível com a presença de elevado teor de argilominerais. Corpos de prova cerâmicos foram preparados por prensagem a seco e queimados em temperaturas ao redor de 855 °C. Os parâmetros resistência mecânica à flexão, retração linear, absorção de água, cor aparente e perda de peso foram medidos. Como resultado, as aplicações industriais destas matérias primas foram analisadas e revistas, bem como novas aplicações foram propostas.

Estudo comparativo das argilas das olarias dos municípios de Alfenas e Areado, MG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Programa de apoio à legalização mineral de olarias da região de Rio Claro (SP)

Esse artigo apresenta os resultados de um projeto denominado de Projeto Parceria, desenvolvido no período de 2007 a 2010, com objetivo de orientar, tecnicamente, os oleiros associados da ASCER, para a correta condução das atividades de extração de matéria-prima das jazidas utilizadas pela indústria oleira. As atividades desenvolvidas, nesse projeto, contemplam a legalização da situação minerária das atuais áreas de extração, orientação em relação à recuperação das áreas degradadas pela mineração e caracterização cerâmica dos materiais argilosos utilizados na produção de tijolos. Fizeram parte desse estudo quatorze Olarias situadas na região de Rio Claro (SP). A legalização das atividades de extração mineral, na área da jazida de cada olaria, conduziu, automaticamente, à legalização ambiental, que está sendo atualmente executada. Duas olarias não puderam regularizar as suas extrações, pois as áreas de suas propriedades estavam oneradas no DNPM. Outras duas olarias não possuíam documentações referentes à parte jurídica das empresas, necessárias para legalização de suas áreas. Os materiais argilosos utilizados pelos oleiros foram caracterizados quanto às suas aplicações cerâmicas como material nobre para a fabricação de telhas e tijolos, gerando produtos de alta qualidade.

Structural and electrical characterization of semiconducting barium-lead-titanate ceramics

BaTiO3 is usually doped to achieve the temperature stability required by device applications, as well as to obtain a large positive temperature coefficient anomaly of resistivity (PTCR). Uniform distribution of dopants among the submicron dielectric particles is the key for optimal control of grain size and microstructure to maintain a high reliability. The system Ba0.84Pb0.16TiO3 was synthesized from high purity BaCO3, TiO2, PbO oxide powders as raw materials. Sb2O3, MnSO4 and ZnO were used as dopants and Al2O3, TiO2 and SiO2 as grain growth controllers. Phase composition was analyzed by using XRD and the microstructure was investigated by SEM. EDS attached to SEM was used to analyze phase composition specially related to abnormal grain growth. Electrical resistivities were measured as a function of temperature and the PTCR effect characterized by an abrupt increase on resistivity.

New starches for the food industry: Curcuma longa and Curcuma zedoaria

The evolution of the food sector has increased interest in the identification of new starches with distinct properties. Curcuma longa and Curcuma zedoaria rhizomes, which are already used in industry to obtain food coloring and pharmaceutical products, may become commercially interesting as starch raw materials. This work aimed to characterize the starch of two Curcuma species. The results revealed that the rhizomes of two species showed low dry matter and high starch contents. The amylose contents of the starches (22% C. longa and 21% C. zedoaria) were similar to potato starch. The results of microscopic analysis showed flat triangular shape and the size was 20-30 mum for two starches. The final viscosity of C longa was high (740 RVU) and the pasting temperature was 81 degreesC. In C. zedoaria the final viscosity was 427 RVU and the pasting temperature was 78 degreesC. These results differed from standard commercially used natural starches. (C) 2003 Elsevier Ltd. All rights reserved.

Preparation of 9/65/35 PLZT thin films deposited by a dip-coating process

Crack-free polycrystalline PLZT (Pb,a)(Zr,Ti)O-3 thin films with the perovskite structure were prepared by dir-coating using the Pechinis process. Lead acetate, hydrated lanthanum carbonate, zirconium n-propoxide and titanium isopropoxide were used as raw materials. The viscosity of the solution was adjusted in the range of 20 to 56 cP and the films were deposited by a dip-coating process on silicon (100) as substrate. Solutions with ionic concentration of 0.1 and 0.2 M were used. Thin film deposition was accomplished by dipping the substrates in the solution with control of withdrawal speed from 5 to 20 mm/min. The thin films were thermally treated in two steps: at 300 degreesC amid 650 degreesC. The influence of withdrawal speed. viscosity, heating rate and ionic concentration on the morphology of PLZT thin film was discussed. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

A linear optimization approach to the combined production planning model

Two fundamental processes usually arise in the production planning of many industries. The first one consists of deciding how many final products of each type have to be produced in each period of a planning horizon, the well-known lot sizing problem. The other process consists of cutting raw materials in stock in order to produce smaller parts used in the assembly of final products, the well-studied cutting stock problem. In this paper the decision variables of these two problems are dependent of each other in order to obtain a global optimum solution. Setups that are typically present in lot sizing problems are relaxed together with integer frequencies of cutting patterns in the cutting problem. Therefore, a large scale linear optimizations problem arises, which is exactly solved by a column generated technique. It is worth noting that this new combined problem still takes the trade-off between storage costs (for final products and the parts) and trim losses (in the cutting process). We present some sets of computational tests, analyzed over three different scenarios. These results show that, by combining the problems and using an exact method, it is possible to obtain significant gains when compared to the usual industrial practice, which solve them in sequence. (C) 2010 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Competência em informação: um fator crítico para a comunicação na atualidade

Information is one of the most essential raw materials of the journalist. Therefore, for a positive professional development in all means of communication, one must use it with quality. Thus, the development of information proficiency can help with the execution of the job in a more efficient and responsible manner. All of which is indispensable facing the importance of the journalistic discourse as a mediator nowadays, as well as the challenges that the journalist faces with the advent of new information and communication technologies.

Urea-Based Synthesis of Zinc Oxide Nanostructures at Low Temperature

The preparation of nanometer-sized structures of zinc oxide (ZnO) from zinc acetate and urea as raw materials was performed using conventional water bath heating and a microwave hydrothermal (MH) method in an aqueous solution. The oxide formation is controlled by decomposition of the added urea in the sealed autoclave. The influence of urea and the synthesis method on the final product formation are discussed. Broadband photoluminescence (PL) behavior in visible-range spectra was observed with a maximum peak centered in the green region which was attributed to different defects and the structural changes involved with ZnO crystals which were produced during the nucleation process.

Acid and fermented silage characterization and determination of apparent digestibility coefficient of crude protein for pacu Piaractus mesopotamicus

Three types of raw materials including commercial waste from saltwater (SW), freshwater fish (FW) and tilapia fillet residue (FR) were used to produce fish silage by either acid digestion (2% formic acid and 2% sulfuric acid) or anaerobic fermentation (5% of Lactobacillus plantarum and 15% sugar cane molasses). Six test diets were used in digestibility trials prepared with 70% reference diet and 30% of each experimental silage. These diets were fed to juvenile pacu Piaractus mesopotamicus (146 g average weight) in triplicate. Fish were kept in 500-L tanks and feces collected by manual extrusion. It was observed for both processes that SW waste always had the highest moisture content and lowest fat and ash. Highest crude protein levels were found in silages from commercial fish waste (SW and FW) made from whole fish unfit for human consumption. However, apparent digestibility coefficients did not vary among diets (P > 0.05). Although values did not differ statistically, fermented silage consistently displayed higher digestibility coefficients compared to acid silage. The silages exhibited relatively high protein digestibility (72.5-80.0%), thus suggesting the feasibility of using fish industry by-products in aquaculture feeds.

Protocolo para ensaios físico-químicos de estabilidade de fitocosméticos

The growing demand for stable, safe and effective cosmetics has required increasingly complex studies by the scientific community and the use of more efficient techniques to determine the stability of these products. The use of active principles from the Brazilian flora has led to the development of numerous products, in the most varied pharmaceutical forms, making it, even more difficult to standardize experimental protocols to certify the stability of cosmetic preparations. While in Brazil there is no one protocol that standardizes the tests that should be carried out to determine product stability, several studies have been conducted in academic laboratories to determine the stability of specific raw materials. The rheological properties of topical use products have to be taken into account in their manufacture, storage and application. The determination of the rheological behavior of a formulation helps in evaluating the physicochemical nature of the vehicle, allowing early signs of physical instability to be detected and thus enabling quality control of the constituents, test formulations and final products. Thermal analysis has also been used to assist in the study of cosmetic stability and differential scanning calorimetry to guide the development of new products. Other tools, such as fluorimetry and laser granulometry can be used to help the study and development of both emulsified and non-emulsified systems. The aim of the present study is to develop a protocol for the investigation of the physical and chemical stability of phytocosmetics - systems containing active compounds extracted from the Brazilian biodiversity.

Meta-heuristic approaches for a soft drink industry problem

The present paper evaluates meta-heuristic approaches to solve a soft drink industry problem. This problem is motivated by a real situation found in soft drink companies, where the lot sizing and scheduling of raw materials in tanks and products in lines must be simultaneously determined. Tabu search, threshold accepting and genetic algorithms are used as procedures to solve the problem at hand. The methods are evaluated with a set of instance already available for this problem. This paper also proposes a new set of complex instances. The computational results comparing these approaches are reported. © 2008 IEEE.

Evaluating genetic algorithms with different population structures on a lot sizing and scheduling problem

This paper studies the use of different population structures in a Genetic Algorithm (GA) applied to lot sizing and scheduling problems. The population approaches are divided into two types: single-population and multi-population. The first type has a non-structured single population. The multi-population type presents non-structured and structured populations organized in binary and ternary trees. Each population approach is tested on lot sizing and scheduling problems found in soft drink companies. These problems have two interdependent levels with decisions concerning raw material storage and soft drink bottling. The challenge is to simultaneously determine the lot sizing and scheduling of raw materials in tanks and products in lines. Computational results are reported allowing determining the better population structure for the set of problem instances evaluated. Copyright 2008 ACM.

Farmacovigilância no Brasil: A relação entre polimorfismo de fármacos, efetividade e segurança dos medicamentos

In spite of the stated Brazilian policy on medicines that their quality, effectiveness and safety should be ensured at reasonable cost, hospitals in the ANVISA Surveillance Network have been receiving notifications of technical complaints, adverse reactions and suspected therapeutic ineffectiveness (STI) of medicines. The purpose of this study was to identify the medicines notified for suspicion of therapeutic ineffectiveness, at a university hospital participating in the national Surveillance Network, and to investigate the existence of polymorphs of any of the drugs involved, by examining the literature. There were 31 notifications of STI in a period of 18 months, concerning 11 different drugs, all of which were 'similar' drugs (neither original nor licensed by originator); five of these could contain polymorphs, according to the literature. However, this does not mean that the other drugs could not contain some unknown polymorphs, more studies being needed on polymorphism, especially in the cases of reported therapeutic ineffectiveness. Therefore, tests of polymorphism should be made part of the routine quality control of the raw materials during the development of medicines and in the studies of pharmaceutical equivalence to 'reference' medicines (innovative brands). The stability test should also involve a study of polymorphism, in order to confirm the solid state stability of the drug. All these measures will assure the effectiveness of medicines, since the reproducibility in the quality of pharmaceutical products could be monitored, as well as the equivalence of each production batch with the batch selected to determine the bioequivalence with the reference brand.