Avaliação do comportamento de argila ativada na presença de água destilada, soluções salinas e inibidores de hidratação catiônicos

The clay swelling is today one of the major problems during the well drilling. Nearly 50% of clays that constitute shale expand easily in the presence of water molecules. During the drilling of a geological formation containing swelling clays, when is feasible the use of water base fluids, it is necessary to apply clay inhibitors. This avoids the incorporation of the cutting to the drilling fluid which is responsible for the wall swelling and crumbling. The aim of this work was to evaluate the synergistic behavior that occurs when swelling clay inhibitors are associated to NaCl and KCl salts. Three swelling clay inhibitors samples, INIB A, INIB B and INIB C, were analyzed. Each inhibitor was characterized by the amount of chlorides and active matter content. For the water-clay interaction evaluation in the presence of various fluids, it was used the Capillary Suction Timer (CST, Fann) and Linear Swell Meter (LSM 2000, Fann). For better interpretation of results, a Design of Experiments (DOE, Umetrics MODDE 7.0 TM) through Result Surface Methodology (RSM) was employed, taking into account the type, the swelling inhibitors concentration and the contact time with the clay. The results showed different efficiencies among the inhibitors employed, and the salt-inhibitors mixtures were more efficient than those products alone. However, for field operation, other parameters should be taking into account, as operational cost, environmental requests and time of application for each product

Peptídeos cíclicos de biomassa vegetal: características, diversidade, biossíntese e atividades biológicas

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

Estruturas vesiculares em misturas de surfactantes catiônicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interação de ácido algínico com surfactantes catiônicos em solução aquosa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Peptídeos cíclicos em espécies do semiárido brasileiro e uma cultivada: caracterização e atividade biológica

Pós-graduação em Química - IQ

Biofungicida à base de derivados anfifílicos catiônicos de quitosana e método de obtenção do mesmo

The present invention relates to biofungicides based on cationic, amphiphilic chitosan derivatives, with increasing proportions of dodecyl groups, for use against the fungus Aspergillus flavus, and to the method for producing said biofungicides.

Biofungicída à base de derivados anfifílicos catiônicos de quitosana e método de obtenção do mesmo

A presente invenção se refere a biofungicidas a base de derivados anfifílicos catiônicos de quitosana, com porporções crescentes de grupamentos dodecil, para serem utilizados contra o fungo Aspergillus flavus, bem com o método de obtenção do mesmo.

Peptídeos cíclicos hepatotóxicos: MALDI-TOF como uma ferramenta analítica

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

Sistema NPPC-NPR2 na espécie bovina: identificação em folículos antrais e modulação na concentração de nucleotídeos cíclicos e na expressão gênica de PDE3 em complexos cumulus-oócito

Pós-graduação em Biociências - FCLAS

Desempenho de movimentos cíclicos e discretos realizados em tarefa de Fitts simulada em computador

Performance of cyclical and discrete movements executed in Fitts’ task simulated by computer Abstract This study compared the performance of cyclical and discrete movements in Fitts’ task simulated by a computer. Twenty male adults, between 25 and 30 years old, participated as volunteers in the study. The software Discrete Aiming Task (v.2.0) simulated the Fitts’ task, in the discrete and cyclical conditions, and provided the movement time (TM). It was manipulated 4 target widths and 3 distances between the targets to provide index of difficulties (ID) from 1 to 6 bits. The ANOVA TWO WAY, 3 (Conditions) x 6 (ID), with repeated measures in the last factor, compared the TM in the different conditions. Regression analysis verified the relationship between TM x ID. There were no significant differences between the conditions; the virtual environment and the mouse were used to explain such results. All movement conditions showed a straight relationship between TM x ID with R²>0.990. Therefore, Fitts’ law showed to be consistent, independently of the movement strategy performed.

Efeito citotóxico e antimicrobiano de análogos de peptídeos catiônicos e sua influencia na expressão de marcadores fenotípicos e genotípicos de mineralização dentinária

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

Estudo da evolução das tensões residuais através da difratometria de raios x em aço rolamento submetido a esforços cíclicos

The micro-deformations caused by cyclic loading origins the variation of the distances between atoms of the crystal lattice producing the irreversible component. In order to study and understand the microstructural behavior of the material this paper investigated the influence suffered by residual stresses in thrust rolling bearing races fabricated in AISI 52100 steel, after tests by cyclic rolling contact in a tribometer at 1m/s under two contact pressures (500 MPa and 1400 MPa) in dry and boundary lubrication conditions. Procedures of tests thermo-acustically isolated were developed for monitoring the contact temperature and sound pressure level signals to establish a comparison between the residual stress measurements, micro-hardness Vickers and micrographic registers searching an indication of wear evolution. The sin²ψ method by X-ray diffraction technique was used to quantify the residual stresses. Three raceway zones were selected for the evaluation of wear and surface morphology after predetermined cycling, comparing with their new condition ("as received"). Micro-hardness and residual stress measurements showed significant changes after the tests and it was possible to observe the relationship between the increase of sound pressure level and the residual stress for dry and lubricated conditions.