Estudo de massa cerâmica triaxial visando à otimização do ciclo de queima da indústria de cerâmica estrutural

Over recent years the structural ceramics industry in Brazil has found a very favorable market for growth. However, difficulties related to productivity and product quality are partially inhibiting this possible growth. An alternative for trying to solve these problems and, thus, provide the pottery industry the feasibility of full development, is the substitution of firewood used in the burning process by natural gas. In order to contribute to this process of technological innovation, this paper studies the effect of co-use of ceramic phyllite and kaolin waste on the properties of a clay matrix, verifying the possible benefits that these raw materials can give to the final product, as well as the possibility of such materials to reduce the heat load necessary to obtain products with equal or superior quality. The study was divided into two steps: characterization of materials and study of formulations. Two clays, a phyllite and a residue of kaolin were characterized by the following techniques: laser granulometry, plasticity index by Atterberg limits, X-ray fluorescence, X-ray diffraction, mineralogical composition by Rietveld, thermogravimetric and differential thermal analysis. To study the formulations, specifically for evaluation of technological properties of the parts, was performed an experimental model that combined planning involving a mixture of three components (standard mass x phyllite x kaolin waste) and a 23 factorial design with central point associated with thermal processing parameters. The experiment was performed with restricted strip-plot randomization. In total, 13 compositional points were investigated within the following constraints: phyllite ≤ 20% by weight, kaolin waste ≤ 40% by weight, and standard mass ≥ 60% by weight. The thermal parameters were used at the following levels: 750 and 950 °C to the firing temperature, 5 and 15 °C/min at the heating rate, 15 and 45min to the baseline. The results showed that the introduction of phyllite and/or kaolin waste in ceramic body produced a number of benefits in properties of the final product, such as: decreased absorption of water, apparent porosity and linear retraction at burn; besides the increase in apparent specific mass and mechanical properties of parts. The best results were obtained in the compositional points where the sum of the levels of kaolin waste and phyllite was maximal (40% by weight), as well as conditions which were used in firing temperatures of 950 °C. Regarding the prospect of savings in heat energy required to form the desired microstructure, the phyllite and the residue of kaolin, for having small particle sizes and constitutions mineralogical phases with the presence of fluxes, contributed to the optimization of the firing cycle.

Síntese de nanopartículas de magnetita via decomposição térmica em meio não-aquoso

This work aims at obtaining nanoparticles of iron oxide, the magnetite one (Fe3O4), via synthesis by thermal decomposition through polyol. Thus, two routes were evaluated: a simple decomposition route assisted by reflux and a hydrothermal route both without synthetic air atmosphere using a synthesis temperature of 260ºC. In this work observed the influence of the observe of surfactants which are generally applied in the synthesis of iron oxide nanoparticles decreasing cluster areas. Further, was observed pure magnetite phase without secondary phases generally found in the iron oxide synthesis, a better control of crystallite size, morphology, crystal structure and magnetic behavior. Finally, the introduction of hydroxyl groups on the nanoparticles surface was analyzed besides its employment in the polymer production with OH radicals. The obtained materials were characterized by XRD, DLS, VSM, TEM, TG and DSC analyses. The results for the magnetite obtainment with a particle size greater than 5 nm and smaller than 11 nm, well defined morphology and good magnetic properties with superparamagnetic behavior. The reflux synthesis was more efficient in the deposition of the hydroxyl groups on the nanoparticles surface

Pirólise térmica e catalítica de resíduos de vácuo gerados no refino de petróleo

In this study, was used a very promising technique called of pyrolysis, which can be used for obtaining products with higher added value. From oils and residues, since the contribution of heavier oils and residues has intensified to the world refining industry, due to the growing demand for fuel, for example, liquid hydrocarbons in the range of gasoline and diesel. The catalytic pyrolysis of vacuum residues was performed with the use of a mesoporous material belonging the M41S family, which was discovered in the early 90s by researchers Mobil Oil Corporation, allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal arrangement of mesopores with pore diameters between 2 and 10 nm and a high specific surface area, making it very promising for use as a catalyst in petroleum refining for catalytic cracking, and their mesopores facilitate the access of large hydrocarbon molecules. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more positive for application in the petrochemical industry. The mesoporous material of the type Al-MCM41 (ratio Si / Al = 50) was synthesized by hydrothermal method starting from the silica gel, NaOH and distilled water added to the gel pseudobohemita synthesis. Driver was used as structural CTMABr. Removal of organic driver (CTMABr) was observed by TG / DTG and FTIR, but this material was characterized by XRD, which was observed the formation of the main peaks characteristic of mesoporous materials. The analysis of adsorption / desorption of nitrogen this material textural parameters were determined. The vacuum residues (VR's) that are products of the bottom of the vacuum distillation tower used in this study are different from oil fields (regions of Ceará and Rio de Janeiro). Previously characterized by various techniques such as FTIR, viscosity, density, SARA, elemental analysis and thermogravimetry, which was performed by thermal and catalytic degradation of vacuum residues. The effect of AlMCM-41 was satisfactory, since promoted a decrease in certain ranges of temperature required in the process of conversion of hydrocarbons, but also promoted a decrease in energy required in the process. Thus enabling lower costs related to energy expenditure from degradation during processing of the waste

Avaliação térmica dos resíduos da destilação atmosférica das blendas - biodiesel/diesel

The worldwide concern regarding the use of sustainable energy and preserving the environment are determining factors in the search for resources and alternative sources of energy and therefore fuel less aggressive nature. In response to these difficulties Biodiesel has emerged as a good solution because it is produced from renewable sources, produces burns cleaner and is easily reproducible. This work was synthesized with biodiesel oil, sunflower via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the blends BX (a proportion of biodiesel X = 5, 10, 15 and 20 %). Atmospheric distillation of the analysis, performed in blends with and without BHT were collected residue generated by each sample and performed a study heat from the thermogravimetric analysis at a heating rate of 10 °C*min-1, nitrogen atmosphere and heating to 600 °C. According to the specifications of Resolution N 7/2008 for biodiesel, it was found that the synthesized material was in accordance with the specifications. For blends showed that the samples are in accordance with the Resolution of ANP N 42/2009. From the TG / DTG curves of the samples of biodiesel, blends and waste can be seen that these show a single loss of thermal decomposition concerning constituents present in each sample. The blends without BHT with ratios of 5%, 10% and 15% biodiesel showed a lower amount of waste (1,07%; 1,09% e 1,10%) to mineral diesel (1,15%). Therefore, it is concluded that the addition of biodiesel with diesel mineral can improve some physico-chemical parameters, but also, depending on the added amount, decreasing the amount of waste generated. This fact is of great importance because the carbonaceous residue can cause problems in mechanical equipment and parts for vehicles, causing more frequent maintenance, and this is not desirable

Modelagem estocástica do índice de radiação ultravioleta na costa leste do nordeste do Brasil

The increase in ultraviolet radiation (UV) at surface, the high incidence of non-melanoma skin cancer (NMSC) in coast of Northeast of Brazil (NEB) and reduction of total ozone were the motivation for the present study. The overall objective was to identify and understand the variability of UV or Index Ultraviolet Radiation (UV Index) in the capitals of the east coast of the NEB and adjust stochastic models to time series of UV index aiming make predictions (interpolations) and forecasts / projections (extrapolations) followed by trend analysis. The methodology consisted of applying multivariate analysis (principal component analysis and cluster analysis), Predictive Mean Matching method for filling gaps in the data, autoregressive distributed lag (ADL) and Mann-Kendal. The modeling via the ADL consisted of parameter estimation, diagnostics, residuals analysis and evaluation of the quality of the predictions and forecasts via mean squared error and Pearson correlation coefficient. The research results indicated that the annual variability of UV in the capital of Rio Grande do Norte (Natal) has a feature in the months of September and October that consisting of a stabilization / reduction of UV index because of the greater annual concentration total ozone. The increased amount of aerosol during this period contributes in lesser intensity for this event. The increased amount of aerosol during this period contributes in lesser intensity for this event. The application of cluster analysis on the east coast of the NEB showed that this event also occurs in the capitals of Paraiba (João Pessoa) and Pernambuco (Recife). Extreme events of UV in NEB were analyzed from the city of Natal and were associated with absence of cloud cover and levels below the annual average of total ozone and did not occurring in the entire region because of the uneven spatial distribution of these variables. The ADL (4, 1) model, adjusted with data of the UV index and total ozone to period 2001-2012 made a the projection / extrapolation for the next 30 years (2013-2043) indicating in end of that period an increase to the UV index of one unit (approximately), case total ozone maintain the downward trend observed in study period

Estudo de pré-formulação para dose fixa combinada dos tuberculostáticos rifampicina, isoniazida, pirazinamida e etambutol (4 em 1)

According to the global framework regarding new cases of tuberculosis, Brazil appears at the 18th place. Thus, the Ministry of Health has defined this disease as a priority in the governmental policies. As a consequence, studies concerning treatment and prevention have increased. Fixed-dose combination formulations (FDC) are recognized as beneficial and are recommended by WHO, but they present instability and loss on rifampicin bioavailability. The main purpose of this work was to carry out a pre-formulation study with the schedule 1 tuberculosis treatment drugs: rifampicin, isoniazid, pyrazinamide and ethambutol and pharmaceutical excipients (lactose, cellulose, magnesium stearate and talc), in order to develop an FDC product (150 mg of rifampicin + 75 mg of isoniazid + 400 mg of pyrazinamide + 250 mg of ethambutol). The studies consisted of the determination of particle size and distribution (Ferret s diameter) and shape through optical microscopy, as well as rheological and technological properties (bulk and tapped densities, Hausner Factor, Carr s Index, repose angle and flux rate) and interactions among drugs and drug excipient through thermal analysis (DSC, DTA, TG and your derivate). The results showed that, except isoniazid, the other drugs presented poor rheological properties, determined by the physical characteristics of the particles: small size and rod like particles shape for rifampicin; rectangular shape for pyrazinamide and ethambutol, beyond its low density. The 4 drug mixture also not presented flowability, particularly that one containing drug quantity indicated for the formulation of FDC products. In this mixture, isoniazid, that has the best flowability, was added in a lower concentration. The addition of microcrystalline cellulose, magnesium stearate and talc to the drug mixtures improved flowability properties. In DSC analysis probable interactions among drugs were found, supporting the hypothesis of ethambutol and pyrazinamide catalysis of the rifampicin-isoniazid reaction resulting in 3- formylrifamycin isonicotinyl hydrazone (HYD) as a degradation product. In the mixtures containing lactose Supertab® DSC curves evidenced incompatibility among drugs and excipient. In the DSC curves of mixtures containing cellulose MC101®, magnesium stearate and talc, no alterations were observed comparing to the drug profiles. The TG/DTG of the binary and ternary mixtures curves showed different thermogravimetrics profiles relating that observed to the drug isolated, with the thermal decomposition early supporting the evidences of incompatibilities showed in the DSC and DTA curves

Caracterização térmica (TG/DTG, DTA, DSC, DSC-fotovisual) de Hormônios bioidênticos (estriol estradiol)

Bioidentical hormones are defined as compounds that have exactly the same chemical and molecular structure as hormones that are produced in the human body. It is believed that the use of hormones may be safer and more effective than the non-bioidentical hormones, because binding to receptors in the organism would be similar to the endogenous hormone. Bioidentical estrogens have been used in menopausal women, as an alternative to traditional hormone replacement therapy. Thermal data of these hormones are scarce in literature. Thermal analysis comprises a group of techniques that allows evaluating the physical-chemistry properties of a drug, while the drug is subjected to a controlled temperature programming. The thermal techniques are used in pharmaceutical studies for characterization of drugs, purity determination, polymorphism identification, compatibility and evaluation of stability. This study aims to characterize the bioidentical hormones estradiol and estriol through thermal techniques TG/DTG, DTA, DSC, DSC-photovisual. By the TG curves analysis was possible to calculated kinetic parameters for the samples. The kinetic data showed that there is good correlation in the different models used. For both estradiol and estriol, was found zero order reaction, which enabled the construction of the vapor pressure curves. Data from DTA and DSC curves of melting point and purity are the same of literature, showed relation with DSC-photovisual results. The analysis DTA curves showed the fusion event had the best linearity for both hormones. In the evaluation of possible degradation products, the analysis of the infrared shows no degradation products in the solid state

Estudo de compatibilidade e estabilidade térmica do ácido retinóico e hidroquinona por termogravimetria

Retinoic acid (RA) and hydroquinone (HQ) assets are widely used in pharmaceutical and cosmetic formulations, for having depigmenting properties and are largely produced in drugstores. To assist in the development of formulations containing the active RA and HQ National Forms of Brazilian Pharmacopoeia (2005 and 2012 ) proposes formulations with different excipients such as cetyl alcohol (AC), cetostearyl alcohol (ACT), methylparaben (MTP), propyl paraben ( PPB), glycerin (GLY), dipropylene glycol (DPG), imidazolidinil urea ( IMD ), cyclomethicone (CCM ), butylated hydroxytoluene (BHT), octyl stearate (ETO), EDTA, decil oleate (ODC) and hydroxipropymethyl celullose (HPMC). One of the difficulties found in most cosmetic formulations is the large number of incompatibilities between the components of the formulations, so the aim this study was to evaluate thermal stability and interactions between these active pharmaceutical ingredients and excipients. The depigmenting agents were analyzed by DSC and TG and excipients were analyzed by TG. The dynamic thermogravimetric curves were obtained on a SHIMADZU thermobalance, model DTG-60, using an alumina crucible, at the heating rate of 10ºC min-1, in the temperature range of 25-900 ºC, under an atmosphere of nitrogen at 50 mL min-1. The DSC curves were obtained using Shimadzu calorimeter, model DSC-60, using aluminum crucible, at the heating rate of 10ºC min-1, in the temperature range of 25-400ºC. The thermogravimetric and calorimetric curves were analyzed using TASYS software SHIMADZU. In this study no were found interactions between AR and the following excipients: MTP, PPB, IMD, ODC, EDTA, CCM, ETO, HPMC. However, were found interactions with the following excipients: AC, ACT, BHT, GLI and DPG. For HQ were found interactions with IMD and DPG. Interactions remained even changing proportions of the mixtures and the ternary. Thus, the studies conducted with excipients of National Formulary from 2005 and 2012 showed that these new excipients do not interact by thermogravimetry with the active pharmaceutical ingredients of this study

Efeitos de diferentes frações inspiradas de oxigênio no índice biespectral em cães submetidos à infusão contínua de propofol

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

Variáveis cardiorrespiratórias, índice biespectral e recuperação anestésica em cães anestesiados pelo isofluorano, tratados ou não com tramadol

Foram avaliadas possíveis alterações cardiorrespiratórias e no índice biespectral em cães anestesiados pelo isofluorano, associado ou não ao tramadol. Utilizaram-se 16 animais, distribuídos em dois grupos denominados GC (grupo-controle) e GT (grupo tramadol). Todos os cães foram induzidos e mantidos sob anestesia com isofluorano. Os animais do GC receberam 0,05ml/kg de solução salina a 0,9% e os do GT 2mg/kg de tramadol, ambos por via intramuscular. Foram avaliados: freqüência cardíaca, pressão arterial sistólica, diastólica e média, eletrocardiografia, freqüência respiratória, saturação de oxiemoglobina, concentração de dióxido de carbono ao final da expiração, índice biespectral e recuperação da anestesia. Concluiu-se que a administração de tramadol em cães anestesiados pelo isofluorano não produz alterações nas variáveis cardiorrespiratórias, no índice biespectral e no tempo de recuperação da anestesia, porém proporciona boa qualidade de recuperação anestésica.

Influência da heparina sódica na ocorrência de laminite eqüina induzida por sobrecarga de carboidratos

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

Thermal comfort indices in individual shelters for dairy calves with different types of roofs

Dentre os materiais de construção utilizados nas instalações rurais, merecem destaque as coberturas, pois são grandes responsáveis pelo conforto térmico, influenciando no balanço térmico no interior das instalações. Este trabalho objetivou avaliar a influência das coberturas sobre a entalpia (H), Carga Térmica Radiante (CTR) e no Índice de Temperatura de Globo Negro e Umidade (ITGU), em abrigos individuais para bezerros leiteiros. O delineamento foi o inteiramente casualizado com três tratamentos: Z - telha de zinco; CA - telha de cimento amianto, e CAB - telha de cimento amianto pintada de branco na face superior. As médias foram comparadas pelo teste de Scott Knott, a 1% de probabilidade. Os resultados mostraram que não houve diferença estatística entre os tratamentos (P<0,01) e o ambiente externo, para a H. Para a CTR, houve diferença estatística entre todos os tratamentos, em que CAB demonstrou menor CTR, 489,28 W m-², seguido do tratamento CA, 506,72 W m-², e Z com maior valor de CTR, 523,55 W m-². Para o ITGU, observaram-se menores valores para CAB (76,8) e CA (77,4), diferindo-se, significativamente do Z, que obteve maior valor (81,6). As telhas com pintura branca em sua face superior promoveram menor CTR e menor ITGU, favorecendo o ambiente térmico da instalação.

Caracterização da água da microbacia do córrego rico avaliada pelo índice de qualidade de água e de estado trófico

A avaliação do índice de qualidade da água (IQA) e do índice de estado trófico médio (IETm) pode subsidiar a formulação de planos de manejo e gestão de sistemas aquáticos. Neste trabalho, foi avaliada a qualidade da água da microbacia do Córrego Rico, que abastece a cidade de Jaboticabal (SP), utilizando o IQA e IETm. As amostragens de água foram realizadas entre setembro-2007 e agosto-2008, em três pontos: a) em uma das nascentes; b) após a Estação de Tratamento de Esgoto de Monte Alto, e c) na captação de água para abastecimento público de Jaboticabal. As amostras foram analisadas quanto aos parâmetros físicos, químicos e microbiológicos: temperatura, oxigênio dissolvido, pH, DBO5, nitrogênio total, fósforo total, turbidez, resíduo total, ortofosfato, clorofila-a e Escherichia coli. de acordo com os resultados obtidos, concluiu-se que: a) as atividades antrópicas às margens do Córrego Rico reduzem a qualidade de sua água, durante os diferentes períodos do ano; b) os valores médios de IQA nos três pontos analisados apresentaram relação direta com os valores médios de IETm, porém ocorreu maior discriminação da qualidade da água pelo IETm, identificando diferentes graus de trofia para os pontos e períodos de amostragens; c) o IQA apresentou melhor diferenciação da qualidade da água entre pontos no período seco e o IETm diferenciou melhor no período chuvoso; d) o processo de autodepuração e/ou a confluência do Córrego Tijuco com o Córrego Rico contribuem para melhor qualidade da água, tornando-a adequada ao abastecimento urbano após tratamento convencional.

Avaliação de método digital para análise do índice funcional do ciático em ratos

This work aimed to study the reproduction and description of technique for digital sampling images during rats gait and determination of the sciatic functional index (SFI), through a glass walkway to obtain shoots with a digital camera. After controlled injury by strangulation of sciatic nerve, with 3mm of length, during 30 seconds, using hemostatic forceps, a group of 32 rats was performed 24 hours before the lesion which served as control and 24 hours, 7, 14 and 21 days after injury. The tests consisted in the filming and shooting each animal in order to observe the view from below (by a mirror to 45 degrees) and subsequently analyzed using the IMAGE-J program. Measures were taken from the lengths of the legs (right and left), and the distance between the ankle. In the analysis of IFC, values close to zero (0) suggest that the function of the sciatic nerve is still preserved and values coming from "less one hundred" (-100) indicate total loss of function. It was verified in this study that 24 hours before surgery the average SFI was -7.07 +/- 7.88 and 24 hours after injury these values rose to an average of -77.95 +/- 13.81, being about 10 times larger, where 78% of the animals showed 60 to 100% of functional loss in motor activity, demonstrated by the gradual recovery over the days analyzed, confirming the accuracy and effectiveness of the proposed methodology. These results suggest that studies can be conducted to simplify and reduce costs using the technique for digital images of footprints during rats gait in the laboratory.

Índice de cobertura vegetal e sua modelagem para cultivares de soja no sul de Minas Gerais

A cobertura vegetal do solo é decisiva para redução dos efeitos erosivos do impacto direto das gotas de chuva na superfície do solo. Desta forma, objetivou-se com este estudo determinar o índice de cobertura vegetal (CV) e desenvolver modelos para sua estimativa para a cultura da soja, usando os atributos climáticos no período de chuvas intensas no Sul de Minas Gerais. As determinações da CV foram feitas semanalmente, na área experimental do Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), no período de novembro de 1999 a maio de 2000, em 28 cultivares de soja com potencial para cultivo nesta região. Para avaliação da cobertura vegetal foi utilizada a metodologia descrita por Stocking (1988). Na modelagem procurou-se relacionar a CV com os valores acumulados dos seguintes atributos climáticos: temperatura média (Tmed), precipitação (PREC) e umidade relativa do ar (UR). Os valores de cobertura vegetal apresentaram uma amplitude de variação de 56 a 83%, sendo BR 162, LO 12 L e M. Soy 108 as cultivares mais eficientes e FT Abyara e Tucano as menos eficientes. O hábito diferencial de crescimento das cultivares ajuda a explicar esse comportamento. O modelo ajustado adequado para estimativa da CV foi: CV = 116589,976 + 0,422 . Tmed + 0,132 . PREC - 0,095 . UR + 0,000024 . Tmed², R² = 0,99 (P < 0,01). A determinação da CV nas diferentes fases de desenvolvimento da cultura é de grande importância, uma vez que seu estabelecimento coincide com o período de maior potencial erosivo das chuvas na região estudada.