Estudo de reações químicas homogêneas via método de Monte Carlo

By using the Monte Carlo simulation platform with probabilistic mathematical functions of the Boltzmann type, , having activation energy and temperature as parameters, it was possible to assess important dynamic aspects of homogeneous chemical reactions of the types A → B and A B. The protocol proved a useful tool in work with the basic concepts of Kinetics and Thermodynamics allowing its application both in class activities and for assisting experimental procedures.

Adsorption isotherm studies of BOD, TSS and colour reduction from palm oil mill effluent (POME) using boiler fly ash

Palm oil is one of the two most important vegetable oils in the world's oil and fats market. The extraction and purification processes generate different kinds of waste generally known as palm oil mill effluent (POME). Earlier studies had indicated the possibility of using boiler fly ash to adsorb impurities and colour in POME treatment. The adsorption treatment of POME using boiler fly ash was further investigated in detail in this work with regards to the reduction of BOD, colour and TSS from palm oil mill effluent. The amount of BOD, colour and TSS adsorbed increased as the weight of the boiler fly ash used was increased. Also, the smaller particle size of 425µm adsorbed more than the 850µm size. Attempts were made to fit the experimental data with the Freundlich, Langmuir and Dubinin-Radushkevich isotherms. The R² values, which ranged from 0.8974-0.9898, 0.8848-0.9824 and 0.6235-0.9101 for Freundlich, Langmuir and Dubinin-Radushkevich isotherms respectively, showed that Freundlich isotherm gave a better fit followed by Langmuir and then Dubinin-Radushkevich isotherm. The sorption trend could be put as BOD > Colour > TSS. The apparent energy of adsorption was found to be 1.25, 0.58 and 0.97 (KJ/mol) for BOD, colour and TSS respectively, showing that sorption process occurs by physiosorption. Therefore, boiler fly ash is capable of reducing BOD, Colour and TSS from POME and hence could be used to develop a good adsorbent for POME treatment.

True believers: the recption of Descartes's meditations by Malebranche and Huet

Both Nicholas Malebranche and Pierre-Daniel Huet were at first positively influenced by Descartes's Meditations, and both came to perceive shortcomings in that work. With respect to mind-body dualism, Malebranche attempted to strengthen Descartes's position by jettisoning clarity and distinctness basing it instead on a principle of intentionality. Huet jettisoned the whole position in favor of skepticism. The source of their different responses lay in their different estimations of Descartes's integrity.

Cirurgião diante das novas terapias para o tratamento do câncer

The cancer treatement has been subjected to substantial changes, mainly concerning clinical specialities. The advances on tumours study, especially related to genetics and molecular biology, greatly increased our understanding about many aspects of carcinogenesis, neoplasic growth and metastasizing process, untill now obscure. In this context, surgery seems to be attained its limits in trying to erradicate completely the disease, and although the great resections made, this aim has not been succeeded in many cases. New treatments are emerging each year and between the most promising we can highlight tumour angiogenesis chemical blocking agents, with highly promising experimental results. At the same time of the beginning of clinical researchs about these drugs, the authors present a review work, with the objective of presenting a general survey of the knowledge achieved about these recently discovered drugs in tumours control.

Chocolate rheology

Rheology is the science that studies the deformation and flow of solids and fluids under the influence of mechanical forces. The rheological measures of a product in the stage of manufacture can be useful in quality control. The microstructure of a product can also be correlated with its rheological behavior allowing for the development of new materials. Rheometry permits attainment of rheological equations applied in process engineering, particularly unit operations that involve heat and mass transfer. Consumer demands make it possible to obtain a product that complies with these requirements. Chocolate industries work with products in a liquid phase in conching, tempering, and also during pumping operations. A good design of each type of equipment is essential for optimum processing. In the design of every process, it is necessary to know the physical characteristics of the product. The rheological behavior of chocolate can help to know the characteristics of application of the product and its consumers. Foods are generally in a metastable state. Their texture depends on the structural changes that occur during processing. Molten chocolate is a suspension with properties that are strongly affected by particle characteristics including not only the dispersed particles but also the fat crystals formed during chocolate cooling and solidification. Chocolate rheology is extensively studied, and it is known that chocolate texture and stability is strongly affected by the presence of specific crystals

Food production in solidarity economy: an issue that goes beyond laws

Abstract Food production within the context of solidarity economy is an alternative way to offer employment and income for a significant part of the Brazilian population. The purpose of this study was to carry out a business diagnosis in order to evaluate the facilities, the production process and hygiene practices of seven solidarity economy enterprises located in the city of Novo Hamburgo, Southern Brazil, that work with food production and sales. Visits took place at the enterprises and a check-list was used to record data. Although food production happens in places with space and setting restrictions, it guarantees distinctive foods with aggregate value, where handlers follow the whole process, from raw materials selection to sales. Basic hygiene principles are followed, as they guarantee the production of food with quality, which contributes towards income generation for participating families. Specific laws that apply to the characteristics and needs of small-scale food production must be written in order to regulate solidarity economy enterprises.