Previsão do módulo de elasticidade transversal de compósitos unidirecionais através de redes neurais mistas

The aim of this study is to create an artificial neural network (ANN) capable of modeling the transverse elasticity modulus (E2) of unidirectional composites. To that end, we used a dataset divided into two parts, one for training and the other for ANN testing. Three types of architectures from different networks were developed, one with only two inputs, one with three inputs and the third with mixed architecture combining an ANN with a model developed by Halpin-Tsai. After algorithm training, the results demonstrate that the use of ANNs is quite promising, given that when they were compared with those of the Halpín-Tsai mathematical model, higher correlation coefficient values and lower root mean square values were observed

Recuperação e purificação de quitosanases usando adsorção em leito expandido com streamline DEAE com modelagem e simulação usando redes neurais

Expanded Bed Adsorption (EBA) is an integrative process that combines concepts of chromatography and fluidization of solids. The many parameters involved and their synergistic effects complicate the optimization of the process. Fortunately, some mathematical tools have been developed in order to guide the investigation of the EBA system. In this work the application of experimental design, phenomenological modeling and artificial neural networks (ANN) in understanding chitosanases adsorption on ion exchange resin Streamline® DEAE have been investigated. The strain Paenibacillus ehimensis NRRL B-23118 was used for chitosanase production. EBA experiments were carried out using a column of 2.6 cm inner diameter with 30.0 cm in height that was coupled to a peristaltic pump. At the bottom of the column there was a distributor of glass beads having a height of 3.0 cm. Assays for residence time distribution (RTD) revelead a high degree of mixing, however, the Richardson-Zaki coefficients showed that the column was on the threshold of stability. Isotherm models fitted the adsorption equilibrium data in the presence of lyotropic salts. The results of experiment design indicated that the ionic strength and superficial velocity are important to the recovery and purity of chitosanases. The molecular mass of the two chitosanases were approximately 23 kDa and 52 kDa as estimated by SDS-PAGE. The phenomenological modeling was aimed to describe the operations in batch and column chromatography. The simulations were performed in Microsoft Visual Studio. The kinetic rate constant model set to kinetic curves efficiently under conditions of initial enzyme activity 0.232, 0.142 e 0.079 UA/mL. The simulated breakthrough curves showed some differences with experimental data, especially regarding the slope. Sensitivity tests of the model on the surface velocity, axial dispersion and initial concentration showed agreement with the literature. The neural network was constructed in MATLAB and Neural Network Toolbox. The cross-validation was used to improve the ability of generalization. The parameters of ANN were improved to obtain the settings 6-6 (enzyme activity) and 9-6 (total protein), as well as tansig transfer function and Levenberg-Marquardt training algorithm. The neural Carlos Eduardo de Araújo Padilha dezembro/2013 9 networks simulations, including all the steps of cycle, showed good agreement with experimental data, with a correlation coefficient of approximately 0.974. The effects of input variables on profiles of the stages of loading, washing and elution were consistent with the literature

Recuperação e purificação de proteínas do soro de queijo tipo coalho usando cromatografia de troca iônica e interação hidrofóbica em leito na forma expandida

Expanded Bed Adsorption plays an important role in the downstream processing mainly for reducing costs as well as steps besides could handling cells homogenates or fermentation broth. In this work Expanded Bed Adsorption was used to recover and purify whey proteins from coalho cheese manufacture using Streamline DEAE and Streamline SP both ionic resins as well as a hydrophobic resin Streamline Phenyl. A column of 2.6 cm inner diameter with 30 cm in height was coupled to a peristaltic pump. Hydrodynamics study was carried out with the three resins using Tris-HCl buffer in concentration of 30, 50 and 70 mM, with pH ranging from 7.0 to 8.0. In this case, assays of the expansion degree as well as Residence Time Distribution (RTD) were carried out. For the recovery and purification steps, a whey sample of 200 mL, was submitted to a column with 25mL of resin previously equilibrated with Tris/HCl (50 mM, pH 7.0) using a expanded bed. After washing, elution was carried out according the technique used. For ionic adsorption elution was carried out using 100 mL of Tris/HCl (50 mM, pH 7.0 in 1M NaCl). For Hydrophobyc interaction elution was carried out using Tris/HCl (50 mM, pH 7.0). Adsorption runs were carried out using the three resins as well as theirs combination. Results showed that for hydrodynamics studies a linear fit was observed for the three resins with a correlation coefficient (R2) about 0.9. In this case, Streamline Phenyl showed highest expansion degree reaching an expansion degree (H0/H) of 2.2. Bed porosity was of 0.7 when both resins Streamline DEAE and Streamline SP were used with StremLine Phenyl showing the highest bed porosity about 0.75. The number of theorical plates were 109, 41.5 and 17.8 and the axial dipersion coefficient (Daxial) were 0.5, 1.4 and 3.7 x 10-6 m2/s, for Streamline DEAE, Streamline SP and Streamline Phenyl, respectively. Whey proteins were adsorved fastly for the three resins with equilibrium reached in 10 minutes. Breakthrough curves showed that most of proteins stays in flowthrough as well as washing steps with 84, 77 and 96%, for Streamline DEAE, Streamline SP and Streamline Phenyl, respectively. It was observed protein peaks during elution for the three resins used. According to these peaks were identified 6 protein bands that could probably be albumin (69 KDa), lactoferrin (76 KDa), lactoperoxidase (89 KDa), β-lactoglobulin (18,3 KDa) e α-lactoalbumin (14 KDa), as well as the dimer of beta-lactoglobulin. The combined system compound for the elution of Streamline DEAE applied to the Streamline SP showed the best purification of whey proteins, mainly of the α-lactoalbumina

Tratamento de água de produção de petróleo visando o aproveitamento na obtenção de barrilha

The petroleum production is associated to the produced water, which has dispersed and dissolved materials that damage not only the environment, but also the petroleum processing units. This study aims at the treatment of produced water focusing mainly on the removal of metals and oil and using this treated water as raw material for the production of sodium carbonate. Initially, it was addressed the removal of the following divalent metals: calcium, magnesium, barium, zinc, copper, iron, and cadmium. For this purpose, surfactants derived from vegetable oils, such as coconut oil, soybean oil, and sunflower oil, were used. The investigation showed that there is a stoichiometric relationship between the metals removed from the produced water and the surfactants used in the process of metals removal. It was also developed a model that correlates the hydrolysis constant of saponified coconut oil with the metal distribution between the resulting stages of the proposed process, flocs and aqueous phases, and relating the results with the pH of the medium. The correlation coefficient obtained was 0.963. Next, the process of producing washing soda (prefiro soda ahs ou sodium carbonate) started. The resulting water from the various treatment approaches from petroleum production water was used. During this stage of the research, it was observed that the surfactant assisted in the produced water treatment, by removing some metals and the dispersed oil entirety. The yield of sodium carbonate production was approximately 80%, and its purity was around 95%. It was also assessed, in the production of sodium carbonate, the influence of the type of reactor, using a continuous reactor and a batch reactor. These tests showed that the process with continuous reactor was not as efficient as the batch process. In general, it can be concluded that the production of sodium carbonate from water of oil production is a feasible process, rendering an effluent that causes a great environmental impact a raw material with large scale industrial use

Relação entre índices fisiológicos aeróbios e desempenho em provas de curta e média duração em ciclistas de elite

Poucos são os estudos que possibilitam verificar quais as respostas fisiológicas são associadas ao desempenho em uma amostra de ciclistas de elite nacional. Portanto, o objetivo do presente estudo foi determinar e relacionar diferentes índices fisiológicos aeróbios com o desempenho em testes contra relógio de 4 e 20km em ciclistas de alto nível. A amostra foi composta por 14 ciclistas profissionais de elite nacional do sexo masculino (28,5 ± 4,7 anos, 73,47 ± 8,29 kg, 176 ± 6,76 cm), que realizaram um teste progressivo em laboratório para a determinação do consumo máximo de oxigênio (VO2max: 62,23 ± 8,28 ml·kg·min-1), intensidade relativa ao VO2max (iVO2max: 500,83 ± 58,65 w), economia de movimento (EM: 0,1166 ± 0,0362 ml·kg·min·w-1) e 1º e 2º limiares ventilatórios (LV1: 348,21 ± 43,26 w; LV2: 417,86 ± 60,79 w, respectivamente). Também foram submetidos a duas provas de 4 e 20km contra relógio. Para correlação entre os índices fisiológicos e desempenho, foi utilizado o coeficiente de correlação de Pearson (p< 0,05). Não foi encontrada correlação entre os índices fisiológicos (VO2max absoluto e relativo, iVO2max, EM, LV1 e LV2) e o desempenho de 4km (r= 0.38; 0.16; -0.33; 0.20; -0.50; -0.20, respectivamente) e 20km (r= 0.24; 0.01; -0.13; -0.12; -0.48; -0.19, respectivamente) contra relógio em atletas de alto nível. Estes resultados sugerem que tais variáveis não apresentam capacidade de explicar o desempenho em provas de contra relógio nas respectivas distâncias, provavelmente, devido à homogeneidade entre os sujeitos.

Development of an amperometric sensor for potassium ions

Hollandite-type manganese oxides are nanofibrous crystals with sub-nanometer open tunnels that provide a unique property for sensing applications. Sensor based on hollandite-type manganese oxide was investigated for amperometric detection of potassium. With an operating potential of +0.63 V versus SCE, potassium ions produce oxidation currents at the sensor, which can be exploited for quantitative determinations. The amperometric signals are linearly proportional to potassium ions concentration in the range 2.7 x 10(-4) to 9.1 x 10(-4) Mol l(-1) with a correlation coefficient of 0.9990. The construction and renewal are simple and inexpensive.

An Electrochemical Sensor Based on Nanostructured Hollandite-type Manganese Oxide for Detection of Potassium Ions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reproducibility of 6-minute walking test in patients with COPD

The reproducibility of the 6-min walking test (6MWT) needs to be more solidly studied. This study aimed to investigate the reproducibility of two 6MWTs performed on subsequent days in a large and representative sample of patients with chronic obstructive pulmonary disease (COPD), and to quantify the learning effect between the two tests, as well as its determinants.In a retrospective observational study, 1,514 patients with COPD performed two 6MWTs on subsequent days. Other measurements included body composition (dual X-ray absorptiometry), dyspnoea (Medical Research Council scale) and comorbidity (Charlson index).Although the 6MWT was reproducible (intraclass correlation coefficient=0.93), patients walked farther in the second test (391 m, 95% CI 155-585 m versus 418 m, 95% CI 185-605 m; p < 0.0001). on average, the second 6MWT increased by 27 m (or 7%), and 82% of patients improved in the second test. Determinants of improvement >= 42 m in the second test (upper limit of the clinically important change) were as follows: first 6MWT < 350 m, Charlson index < 2 and body mass index < 30 kg.m(-2) (OR 2.49, 0.76 and 0.60, respectively).The 6MWT was statistically reproducible in a representative sample of patients with COPD. However, the vast majority of patients improved significantly in the second test by an average learning effect of 27 m.

EFFECT of GAMMA IRRADIATION on CAPROLACTAM MIGRATION FROM MULTILAYER POLYAMIDE 6 FILMS INTO WATER FOOD SIMULANT and VALIDATION of THE METHOD

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

LC Assay for Ciprofloxacin Hydrochloride Ophthalmic Solution

The objective of the current study was to develop and subsequently validate a simple, sensitive and precise reversed-phase LC method for the determination of ciprofloxacin hydrochloride in ophthalmic solution form. The chromatographic separation of ciprofloxacin hydrochloride was achieved on a Symmetry Waters C(18) column using UV detection at 275 nm. The optimized mobile phase consisted of 2.5% acetic acid solution: methanol:acetonitrile (70:15:15, v/v/v). The proposed method provided linear responses within the concentration range 1.0-6.0 mu g mL(-1) for ciprofloxacin hydrochloride. Correlation coefficient (r) for the ciprofloxacin hydrochloride was 0.9994. The precision of the method was demonstrated using intra- and inter-day assay RSD% values which were less than 5% in all instances. No interference from any components of pharmaceutical dosage forms was observed.

Comparative study of analytical methods by direct and first-derivative UV spectrophotometry for evaluation of losartan potassium in capsules

O losartano potássico é um agente anti-hipertensivo não peptídico, que exerce sua ação por bloqueio específico dos receptores da angiotensina II. Este trabalho propôs a validação e aplicação de métodos analíticos orientados ao controle de qualidade de losartano potássico 50 mg na forma farmacêutica cápsula, utilizando a espectrofotometria direta e derivada de primeira ordem na região do UV. Baseado nas características espectrofotométricas de losartano potássico, um sinal a 205 nm do espectro de ordem zero e um sinal a 234 nm do espectro de primeira derivada foram adequados para a quantificação. Os resultados foram usados para comparar essas duas técnicas instrumentais. O coeficiente de correlação entre as respostas e as concentrações de losartano potássico na faixa de 3,0-7,0 mg L-1 e 6,0-14,0 mg L-1 para espectrofotometria direta e derivada de primeira ordem em solução aquosa, respectivamente, foi de (r) of 0,9999 para ambos os casos. Os métodos foram aplicados para quantificação de losartano potássico em cápsulas obtidas de farmácias de manipulação locais e demonstraram ser eficientes, fáceis de aplicar e de baixo custo. Além disso, não necessitam de reagentes poluentes e requerem equipamentos economicamente viáveis.

Migração de ε-caprolactama de embalagens contendo poliamida 6 para simulante ácido acético 3% e validação do método analítico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Consistência interna e reprodutibilidade da versão em português do critério de diagnóstico na pesquisa para desordens temporomandibulares (RDC/TMD - Eixo II)

OBJETIVO: Estudar a confiabilidade, da versão em português, do questionário para o diagnóstico psicológico e psicossocial dos indivíduos com desordens temporomandibulares (RDC/TMD). MÉTODOS: Foram entrevistados 109 indivíduos, de ambos sexos, que demandaram atendimento junto à Clínica de Fisioterapia do Centro Universitário de Araraquara, de janeiro a julho de 2006. Os questionários foram aplicados por um único examinador. Após duas semanas, o mesmo foi reaplicado em 36 indivíduos. Para avaliação da consistência interna do método, utilizou-se o Coeficiente Alfa de Cronbach; para análise da reprodutibilidade intra-examinador, o Coeficiente de Correlação Intraclasse (ro) e a estatística Kappa (kapa), respectivamente às variáveis de natureza quantitativa e qualitativa. RESULTADOS: A consistência interna para as dimensões intensidade da dor crônica e incapacidade; limitação da função mandibular; sintomas físicos não-específicos, incluindo os itens de dor; sintomas físicos não-específicos, excluindo os itens de dor e depressão foi de 0,8479, 0,8971, 0,8673, 0,8080 e 0,9270 respectivamente, atestando ao método excelente validade interna. Obteve-se excelente concordância intra-examinador para as questões referentes ao tempo de presença da dor e sua gradação, e boa para a questão referente à dor presente. Os menores valores de kapa relacionaram-se aos itens de sintomas físicos e depressão. A percepção de estalos ou rangidos pelos indivíduos apresentou concordância regular bem como a questão referente à procura de profissional para tratamento da dor. As demais questões apresentaram reprodutibilidade boa e ótima, sendo que a maioria dessas apresentou nível máximo de concordância. CONCLUSÃO: A versão adaptada para o português mostrou-se confiável para detecção das alterações psicológicas e psicossociais associadas às desordens temporomandibulares.

Flow-injection spectrophotometric determination of novalgin in phrmaceuticals using micellar medium

A sensitive flow-injection (FI) procedure with spectrophotometric detection in a micellar medium is proposed for the determination of novalgin. The method is based on the instantaneous formation of a red-orange product (lambda(max) = 510 nm) after the reaction between novalgin and p-dimethylaminocinnamaldehyde (p-DAC) in a dilute acid medium. The sensitivity of this reaction was increased by a factor of 5.6 in the presence of sodium dodecyl sulfate (SDS). Experimental design methodologies were used to optimize the chemical and FI variables. The calibration curve was linear in the range of 1.45 x 10(-6) to 2.90 x 10(-5) mol L-1 with an excellent correlation coefficient (r = 0.9999). The detection limit was 1.31 x 10(-7) mol L-1 (n = 20, RSD = 2.0%). No interferences were observed from the common excipients. The results obtained by the proposed method were favorably compared with those given by the iodometric reference method at 95% confidence level.

Waveshapes of continuing currents and properties of M-components in natural positive cloud-to-ground lightning

This work analyses the waveshapes of continuing currents and parameters of M-components in positive cloud-to-ground (CG) flashes through high-speed GPS synchronized videos. The dataset is composed of only long continuing currents (with duration longer than 40 ms) and was selected from more than 800 flashes recorded in Sao Jose dos Campos (45.864 degrees W, 23.215 degrees S) and Uruguaiana (29.806 degrees W, 57.005 degrees S) in Southeast and South of Brazil, respectively, during 2003 to 2007 summers. The videos are compared with data obtained by the Brazilian Lightning Location System (BrasilDAT) in order to determine the polarity of each flash and select only positive cases. There are only two studies of waveshapes of continuing currents in the literature. One is based on direct current measurements of triggered lightning, in which four different types of waveshapes were observed; and the other is based on measurements of luminosity variations in high-speed videos of CG negative lightning, in which besides the four types above mentioned two additional types were observed. The present work is an extension of the latter, using the same method but now applied to obtain the waveshapes of positive CG lightning. As far as the authors know, this is the first report on M-components in positive continuing currents. We also have used the luminosity-versus-time graphs to observe their occurrence and measure some parameters (duration, elapsed time and time between two successive M-components), whose statistics are presented and compared in detail to the data for negative flashes. We have plotted a histogram of the M-components elapsed time over the total duration of the continuing current for positive flashes, which presented an exponential decay (correlation coefficient: 0.83), similar to what has been observed for negative flashes. (C) 2008 Elsevier B.V. All rights reserved.