Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect

Estimation of the lower flammability limits of C-H compounds at 25 degrees C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 degrees C H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C H compounds. When tested for a temperature range from 5 degrees C to 100 degrees C , the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene. (C) 2014 Elsevier B.V. All rights reserved.

Participação do óxido nítrico na fisiopatologia da doença renal crônica

Nitric oxide (NO) is a free radical gas, inorganic, which has seven electrons of nitrogen and oxygen eight, possessing an unpaired electron. This radical is produced from L-arginine by a reaction mediated by the enzyme NO synthase. NO it is about a radical of who acts abundant on a variety of biological processes, particularly when produced by endothelial cells plays a significant role in cardiovascular control, as a modulator of peripheral vascular resistance and platelet aggregation. This free radical has also a neurotransmitter and mediator of the immune system. NO kidney function has been considered in many physiological functions such as: (a) regulation of hemodynamics and glomerular function tubuloglomerular, (b) participation in pressure natriuresis (c) maintaining medullar perfusion (d) inhibiting sodium reabsorption tubular, and (e) acting as a modulator of the activity of the sympathetic nervous system. Given these functions, the occurrence of its deficiency is associated with chronic kidney disease (CKD) in vasoconstriction and consequently glomerular hypertension, high blood pressure (HBP), proteinuria and progression of renal dysfunction. This work has the scope to describe the role of NO in renal physiology and pathophysiology of CKD.

Monte Carlo simulation of water-tetrahydrofuran mixtures

Monte Carlo simulations of water-tetrahydrofuran (THF) mixtures were performed in the isothermal-isobaric ensemble (NPT) at T = 298 K and p = 1 atm. The interaction energy was calculated using the TIP4P model for water and a five-site united atom representation for the THF molecule. The potential energy surfaces for water-THF interactions were obtained by using combining rules and the original potential functions used for pure liquids. Theoretical values obtained for the average interaction energy as a function of concentration are in good agreement with available experimental data. Results from the partitioning of the total interaction energy into water-water, water-THF and THF-THF contributions are presented. These results are useful to distinguish between the quantitative contributions of these molecular interactions to the energetic behavior of the water-THF mixing process. The radial distribution functions for HW-OTHF and OW-OTHF site-site interactions show the salient features of hydrogen-bonded liquids. Comparison of the average number of water-water complexes interacting through hydrogen bonding in water-THF and water-methanol mixtures shows an enhancement of the water-water coordination number in a THF rich environment. © 1995.

Nasalance during use of pharyngeal and glottal place of production

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise estrutural de aerogéis via espalhamento de luz a baixo ângulo

The sol-gel process is a method for obtaining vitreous or vitro-ceramic materials which, are prepared a sol and by drying the liquid phase. This technique has been used extensively for the preparation of glassy gels, films, fibers and particles from the hydrolysis and polycondensation reactions of metal alkoxides. The usual methods for drying are: evaporation drying (xerogels), freeze drying (criogéis) and via supercritical CO2 extraction (aerogels). In the present work, we studied the preparation of silica gels by the sol-gel process from the hydrolysis of alkoxides tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTS). The hydrolysis was promoted from GPTS and TEOS in proportion (4: 1) under acidic conditions. The hydrolysis reaction was promoted inside a Becker at room temperature. After hydrolyses the prepared sol had pH 2, and kept under mechanical agitation for a period of 1 hour. In order to accelerate the polycondensation reaction, the pH was corrected to a value near 5 by slowly adding NH4OH. Then the sols were leaked in sealed polycarbonate containers and maintained for 20 days at 40°C for gelation. Silica aerogels were prepared via supercritical CO2 extraction of the wet gel at temperature and pressure higher than 31°C and 74 atm, in an autoclave specially developed for the process. The structural characteristics were studied in the dry gel (aerogel). Aerogels were then characterized by nitrogen adsorption and small angle light scattering. The nitrogen adsorption data were analyzed for the determination of the BET specific surface (SBET), the total pore volume Vp, the pore mean size (lP=4Vp/SBET), the particle mean size (lS) and the pore size distribution (PSD). And the data from small angle light scattering were analyzed to determine the correlation function (γ'), the area per unit volume (S/V), average pore size (l ) and the average particle size...

Efeito Diabetes mellitus gestacional na modulação de genes relacionados ao metabolismo mitocondrial e a implicação na predisposiçao do recém-nascido à obesidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de um modelo experimental de hidrocefalia por neurocisticercose

Pós-graduação em Bases Gerais da Cirurgia - FMB

Níveis plasmáticos de nitrito/nitrato, GMPc e cortisol em mulheres normotensas e hipertensas após a menopausa: efeito crônico do exercício físico e exposição aguda à L-arginina

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

Análise da modulação autonômica em repouso e em resposta ao Tilt Test ativo em crianças com diabetes tipo 1

Pós-graduação em Fisioterapia - FCT

Efeito do plasma rico em uréia na apoptose de neutrófilos de cães

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

Reabsorção condilar progressiva: revisão de literatura

The progressive condylar resorption is a irreversible complication that can result in malocclusion and facial deformity that can happen especially in postoperative orthognathic surgery of mandibular advancement or combined surgery. Predominantly affect young women, bearers of malocclusions of skeletal class II and with incidence of temporomandibular disorders prior to surgical treatment. Its exact etiology and pathogenesis remain unclear. The purpose of this article is to make a literature review of the last 10 years on the progressive condylar resorption. For this, we used the Medline database for articles in the English language. Then, 13 articles were found, evaluated and compared on predisposing factors, etiology, diagnosis and clinical management.

Sintomas auditivos e desordens temporomandibulares

Introduction: A variety of hypotheses have been proposed to explain the association between temporomandibular disorders and hearing symptoms, including the many anatomical and/or neurological ways, as of a muscle or joint dysfunction, can cause such symptoms. Objective: The purpose of this study is to discuss, through a systematic review of literature, the interrelation between hearing symptoms and temporomandibular disorders. Material and Methods: We consulted the Medline/PubMed, ISI and Scielo in the period 1918 to 2008. The terms related to the research were: “temporomandibular disorders”, “signs and symptoms of temporomandibular disorders”, “otologic symptoms” and “aural symptoms”, where 19 papers were included using the pre-selected criteria for the manufacture of a meta-analysis. Results: According to the findings, the hearing symptoms most often associated with temporomandibular disorders were otalgia and tinnitus, followed by vertigo and hearing loss, respectively. Conclusions: It’s clear the correlation between hearing symptoms and temporomandibular disorders, however there is a need clinical and scientific research more complex to prove the specific cause-effect relationships between them.

Dor orofacial

The orofacial pain, also known by the generic term dysfunction, is highly prevalent in the general population, causing great discomfort to the patients. For this reason, there is great importance of dentist’s participation in practice and in the process of proper diagnosis of this disease, which in modern times has become increasingly important as guides the best treatment. Thus, this study was aimed to review the main causes, diagnosis, main symptoms and treatment modalities, to serve as a guide to the dentist. Moreover, it also aims to review the main etiologic factors commonly associated, as emotional stress and muscular hyperactivity, to clearly identify signs and symptoms, so the dentist is able to realize simple treatment in your particular office or recognizes complex cases that could be send for treatment to multidisciplinary teams.

Aspectos oclusais na etiologia das desordenstemporomandibulares

Since the occlusion area is presented in almost all specialties of Dentistry, its relationship with the health of the patient has been shown. The etiology of temporomandibular disorders is multifactorial and the occlusion is considered an etiologic factor. This study aimed to discuss the functional occlusion aspects and the presence of temporomandibular disorders. Literature Review: The loss of orthopedic balance can induce temporomandibular disorder. Therefore, both the physiological and functional occlusions have been analyzed as a dental relation. Several functional occlusal factors have been linked to the temporomandibular disorders such as deviations of centric relation to maximum intercuspation, occlusal interferences, absence of posterior teeth, changes on the occlusion vertical dimension, malocclusion, orthodontic treatment and parafunction. Conclusion: The most common occlusal factors related to temporomandibular disorders are quite frequent; however, the diagnosis and treatment of such disorders should be considered individually

Recuperação da dimensão vertical em pacientes com parafunção severa

The association between emotional stress and intense bruxism has as consequence the Temporomandibular Disorder (TMD), which is an increasingly apparent problem at the dental clinic, requiring judicious means of diagnosis and especially treatment.. Several factors, of equivalent importance, may be related to the DTM, one of them is the loss of vertical dimension of occlusion (VDO), and parafunctional habits and also the loss of stable contacts between the posterior teeth or lack thereof, which generates an increase functional anterior teeth for excessive wear or buccal and consequent.. This paper proposes using a clinical case, to present and discuss the steps for clinical diagnosis, planning and execution of oral rehabilitation with Fixed Partial Denture for restoring vertical dimension of occlusion in a patient with severe parafunction.. Oral rehabilitation of these patients should be carefully planned, respecting the functional and aesthetic aspects.. The parafunction control by monitoring the Temporomandibular Disorder is essential to the longitudinal prediction of rehabilitation performed in these types of rehabilitative treatment.