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The Behavior of Zeta Potential of Silica Suspensions

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New Journal of Glass and Ceramics 2014年第2期4卷 29-37页

作者： Jose Antonio Alves Junior joao Baptista Baldo Departamento de Materiais Universidade Federal de Sao CarlosSao CarlosBrazil

Zeta potential is one of the most relevant parameters controlling the rheological behavior of ceramic suspensions. In this work, it was observed that for pH values below the isoelectric point (IEP), the positive value of zeta potential of water suspensions of α-quartz and α-cristobalite, experiences a sudden steep increase with the increase in specific surface area of the powders. For pH values above the IEP, the zeta potential values of crystalline forms of silica (α-quartz and α-cristobalite), get gradually more negative with the increase in pH. Conversely in the case of vitreous silica, for pH values above 6, there occurs a steep change towards more negative values of zeta potential than those presented by quartz and cristobalite. These findings have not yet been accounted for in the DLVO theory but may provide subsidies for better understanding of how to stabilize and destabilize crystalline and vitreous silica water suspensions.

关键词： Silica Slurries Zeta Potential Stabilization Iso-Electronic Point Silica

Application of NURBS for Obtaining Free Form Curves and Surfaces in Spur and Helical Gears by Using CMM （Coordinate Measurement Machine）

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Journal of Mechanics Engineering and Automation 2014年第5期4卷 432-440页

作者： Luiz Henrique Melo Silva Nobrega Verilton Nunes da Silva Jose carlos de Lima Junior joao Bosco de Aquino Silva Igor Lucena Peixoto Andrezza Rafael Franklin Alves Silva Department of Mechanical Engineering Federal University of Paraiba Jo6o Pessoa 58051-900 Brazil Department of Mechanical Engineering Federal Institute of Bahia SimOes Filho 43700-000 Brazil Informatics Center Federal University of Paraiba Jo6o Pessoa 58051-900 Brazil Department of Mechanical Engineering Federal Institute of Paraiba Jo6o Pessoa 58900-000 Brazil

Currently, engineering processes require reduced manufacturing time and low cost, in addition to the growing demand for workpieces with high accuracy. Workpieces with complex geometries and free forms has been a common practice in industries from different sectors such as： automotive, aeronautics, bioengineering among others. One way to satisfy the market requirements satisfactorily is making measurements more efficient to make the production process faster, in other words, it is necessary to make the inspection system more accurate and flexible. The coordinate measuring evolved over the past three decades and today it is the technology that best meets the requirements of modem manufacturing through CMMs （coordinate measurement machines）. The CMMs are important tool for design, fabrication and inspection of manufactured products, also used in the application of reverse engineering. These machines are also used by engineers in order to produce an accurate digital model in a virtual space for later use in CAD （computer-aided design）/CAM （computer-aided manufacturing）. It is worth mentioning that the accuracy of the modeling process of given piece depends on the number of control points that are captured on the workpiece surface. Consequently, the laser inspection systems are the best tools for use in reverse engineering, but more expensive when compared to contact measurement systems that use the TTP （touch trigger probe）, also used by CMMs. In this case, this paper aims to present an approach based on NURBS （non-uniform rational B-splines） to obtain free form curves and surfaces from a group of points obtained by using a contact sensor, the touch trigger probe. NURBS is an important mathematical tool and consists of generalizations of Bezier curves and surfaces and B-splines. The approach proposed in this paper can be applied for obtaining free form curves and surfaces in spur and helical gears. Experimental results obtained by measuring spur gears showed that the NU

关键词： Coordinate measurement machine touch trigger probe NURBS reverse engineering.

^(99m)Tc in the evaluation of microleakage of composite resin restorations with SonicFill^(TM).An in vitro experimental model

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Open Journal of Stomatology 2012年第4期2卷 340-347页

作者： Carrilho Eunice Abrantes Margarida Casalta-Lopes joao Botelho Filomena Paula Anabela Ambrósio Pedro Marto carlos Miguel Rebelo Diana Marques Joana Polido Mário Ferreira Manuel Marques Faculty of Medicine University of CoimbraCoimbraPortugal

Introduction: The composite SonicFillTM (Kerr/Kavo) is indicated for posterior restorations, with a single increment up to 5 mm due to reduced polymerization shrinkage, thus reducing working time. Aim: Evaluation of marginal microleakage with SonicFillTM. Method and Materials: There were sectioned sixty noncarious human molars in the occluso-cervical direction. Class V cavities were prepared on each tooth with gingival margin walls in a standardized way. The specimens were divided into 4 groups: group 1—restored with SonicFillTM (Kerr/Kavo), group 2—restored with FiltekTM SupremeXTE (3M ESPE), group 3—the cavities were not restored;group 4—restored with SonicFillTM (Kerr/Kavo). In groups 1, 2 and 4 the enamel was conditioned with 37% orthophosphoric acid and applied the self-etch adhesive system Clear- fillTM SE BOND (Kuraray). The specimens were stored in distilled water at 37?C for 7 days. After, the specimens, were immersed in a solution of 99mTc-Pertechnetate and the radioactivity was assessed with a gamma camera. The nonparametric Kruskal-Wallis and Mann-Whitney test with Bonferroni correction at a significance level of 5% were used for the statistical analyses. Results: There are significant differences between the positive and negative control groups and between these and experimental groups (p TM and FiltekTM SupremeXTE. Conclusion: The new composite SonicFillTM and FiltekTM SupremeXTE showed no difference concerning dye penetration. The Sonic- FillTM restorative system showed no influence in concerning microleakage.

关键词： Posterior resin Composites Composite Restorations Polymerization Stress Polymerization Shrinkage Microleakage Thermocycling

Automation System for Quality Control in Manufacture of Iodine-125 Sealed Sources Used in Brachytherapy

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Journal of Physical Science and Application 2013年第6期3卷 380-386页

作者： Samir Luiz Somessari Anselmo Feher Francisco Edmundo Sprenger Maria Elisa Chuery Martins Rostelato carlos A. Zeituni joao A. Moura Osvaldo Luiz da Costa Wilson Aparecido Parejo Calvo Radiation Technology Centre Nuclear and Energy Research Institute National Nuclear Energy Commission (1PEN-CNEN/SP) SaoPaulo 05508-000 Brazil

The objective of this work is to develop an automation system for quality control （QC） in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding （LBW）. These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of lodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller （PLC）, step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices （GMP）. Nowadays, the Radiation Technology Centre at IPEN-CNEN/SP imports and distributes 36,000 lodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 lodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil.

关键词： Iodine-125 seeds quality control brachytherapy automation system (Nd:YAG) laser welding automation system.

The Threshold Percolation Volume Fraction of Vitreous Silica on the Thermal Expansion Behavior of Quartz

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Journal of Materials Science and Chemical Engineering 2019年第6期7卷 1-6页

作者： José Antonio Alves Júnior joao Baptista Baldo The Federal University of Sao carlos(UFSCar) Materials Engineering Department(DEMa)Sao CarlosSPBrazil

In this work, it is shown how the additions of vitreous silica of particle size ?C.

关键词： Quartz Vitreous Silica Thermal Expansion Behavior Percolation Threshold

The Effect of Nano-Alumina Particles Generated in Situ in the Matrix of Ultralow and No Cement 85 wt%Al_(2)O_(3) Refractory Castables

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Journal of Materials Science and Chemical Engineering 2019年第6期7卷 7-22页

作者： José Antonio Alves Júnior joao Baptista Baldo Department of Materials Engineering Federal University of Sao Carlos via Washington LuisSao CarlosSPBrazil

Advanced high alumina refractory castables of ultra-low and to cement types, are well-known because of their ability on developing similar and/or superior thermal and mechanical properties. Following the recent trend of including nanoparticles in refractory castables, in this work, it is presented a novel way to obtain the benefit effects on the thermal and mechanical properties, promoted by the development in situ, of alumina’s nanoparticles in the matrix of castable (85 wt% Al2O3). The alumina nanoparticles were originated in situ after firing, due to the pyrolysis and oxidation of an aqueous resin, produced by the Pechini process. The resin played a double role, one as mixing liquid vehicle and the other as the aluminum oxide nanoparticles precursor. The results indicate a strong increase in flexural strength and elastic modulus as well as leading to a higher residual strength after thermal shock.

关键词： Low Cement Refractory Castable Alumina Nanoparticles Elastic Modulus Impulse Excitation Technique

Diagnostic Value between 1984 and 2018 of Transrectal Biopsy Guided by Ultrasonography after Radical Prostatectomy

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Journal of Pharmacy and Pharmacology 2019年第8期7卷 459-472页

作者： Luiz carlos de Araújo Souza Vinícius Carvalhêdo Cunha Hugo Oliveira de Figueiredo Cavalcanti joao Ricardo Alves Grimar de Oliveira Paula Sandra Lúcia Branco Mendes Coutinho Undergraduates of Medicine in the University Center of Brasilia (UniCEUB) Physician Anatomopathologist by Hospital Base of the Federal District (HBDF) Physician Urologist of the Clinical Body of the Hospital Base of the District Federal and Urocentro (HBDF) Physician Urologist by Hospital Base of the Federal District (HBDF) Physician Anatomopathologist and Head of the Department of Cytopathology and Anatomical Pathology of the Hospital Base of the Federal District (NUCAP-HBDF)

Objectives—to determine correlation between GSs(Gleason scores)on needle biopsy and RP(radical prostatectomy),evaluating diagnostic tests on biopsy and RP within the last years,between 1984 and ***—analysis of 100 patients,diagnosed with PCa(prostate cancer)needle biopsy using 18-gauge needle,who underwent RP with lymphadenectomy and for which preoperative and postoperative GSs were *** group analysis used three categorization schemes for differentiation:mild,moderate and poor for the whole group and we determined SE(sensitivity),SP(specificity),PVPR(positive predictive value),negative predictive value and ***—we found that 42%of the patients had no changes between GS on biopsy and prostatectomy,while 20%were overgraded and 38%undergraded by needle *** of+1 point in GS(32%)or-1 point(17%)was the most *** patients were classified as moderately differentiated by biopsies(78 and 35%in scheme 1 and 2 or 3,respectively),while 43%of patients received an intermediate differentiation *** accuracy varied from 44 to 76%for the analysis of all three ***—there are differences in correlation between GS on biopsy and on surgical specimen,and Gleason’s graduation also depends on the experience of the *** have shown that sextant biopsies using 18-gauge and a same group of pathologists showed acceptable concordance values(42%)between the GS on biopsy and prostatectomy.

关键词： PCa transrectal biopsy guided by ultrasonography RP PSA(prostate specific antigen)

Use of radiation in strains of Saccharomyces cerevisiae:A new technique for industrial applications

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Advances in Bioscience and Biotechnology 2013年第3期4卷 346-351页

作者： Rafael O.Andrette joao D.T.Arruda-Neto Thiago O.Basso Luiz carlos Basso Erika Cavalcante-Silva Maria C.Bittencourt-Oliveira Godofredo C.Genofre Physics Institute University of Sao PauloSao PauloBrazil CEPESq/UniItalo-Italy-Brazilian University Center Sao PauloBrazil Inter-Unities Graduation Program on Biotechnology University of Sao PauloSao PauloBrazil Department of Biological Sciences Luiz de Queiroz College of Agriculture/ESALQUniversity of Sao PauloPiracicabaBrazil Laboratory of Cyanobacteria ESALQUniversity of Sao PauloSao PauloBrazil Institute of Biosciences University of Sao PauloSao PauloBrazil

During the industrial fermentation process in the production of fuel ethanol, yeasts are subject to several stressing conditions. The survival and the permanence of strains introduced in the process correlate with the capability of these yeasts in resisting to physical and chemical stresses, as well as their recovering ability to compete with contaminating micro-organisms commonly present in this industrial process. We aim at the selection of Saccharomyces cere visiae strains having this capability and ability. In this sense, cultivations of strains with industrial interest were irradiated with gammas ray at a wide dose interval. Growing curves for the strains were analyzed by means of their relative growth, a new concept here introduced, which allows a better understanding of the growing and recovering processes following radiative stress. It was found that gamma radiation could be used as an alternative method to quantify growing capabilities of S. cerevisiae strains under stressing conditions. It was also shown that this radiological method could be utilized as an additional procedure to select best robust industrial strains. This radiological method simplifies traditional analysis of strain viability, by avoiding the great number of necessary and consecutive fermentation assays.

关键词： Saccharomyces cerevisiae Industrial Yeast Gamma Radiation Evaluation Method Industrial Fermentation Ethanol

Use of Calcined Bauxite Waste as a Supplementary Cementitious Material： Study of Pozzolanic Activity

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材料科学与工程（中英文A版） 2014年第5期4卷 172-178页

作者： Daniel Veras Ribeiro joao Antbnio Labrincha Moircio Raymundo Morelli Department of Materials Science and Technology / Federal University of Bahia Rua Aristides Novis Salvador 40210-630 BABrazil Ceramics and Glass Engineering Department University of Aveiro & CICECO Campus Universit6rio de Santiago Aveiro3810-193 Portugal Department of Materials Engineering~Federal University of $6o carlos Rodovia Washington Luis S6o Carlos/SP 13566-550Brazil