bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture Behavior of 316 Stainless Steel under Creep at 600 and 800°C
Authors: Monteiro Sergio Neves , Muylaert Margem Frederico , de Oliveira Braga Fabio , Louro Luis Henrique Leme
Published: August 2016

The fracture characteristics of two AISI 316 austenitic stainless steels, creep-tested at constant load and temperatures of 600 and 800°C, were studied by scanning electron microscopy. The morphological aspects of the fracture were analyzed and correlated to the ductility level attained under creep. In one of the 316 steels, a marked change from ductile to intergranular mode of fracture was observed in going from 600 to 800°C. It is proposed that the condition for crack nucleation at precipitates as well as grain boundary oxidation are responsible for these microstructural changes.
Elasto-Plastic Modeling of the Limit Strains in Metallic Sheets
Authors: Cardoso M.C. , Moreira Luciano Pessanha , Freitas M.C.S.
Published: August 2016

In this work, the model of Marciniak and Kuczynski, hereafter referred to as the M-K model, was extended to account for the elastic strains to forecast the Forming Limit Curve (FLC) of metallic sheets. The return mapping algorithm is adopted where an elastic predictor step is performed with the generalized Hooke’s law and the plastic correction step is performed assuming the isotropic work-hardening together with the associated flow rule. The current M-K model predicted quite well both experimental and rigid-plastic results obtained for an IF steel sheet. Also, the principal stresses predicted by the elasto-plastic M-K model provided a good agreement with the experimental Forming Limit Stress Diagram (FLSD) of a Bake-Hardening steel sheet. Therefore, the elastic strains should be taken into account in the modeling of limit strains in metallic sheets, especially in the case of advanced high strength steels for which the Young modulus decreases with the plastic strain.
Characterization of Residual Stresses and Microstructural by Technique of Magnetic Barkhausen Noise of API 5L X80 Steel Heat Treatment
Authors: Correa Sandro Rosa , de Campos Marcos Flavio , Marcelo C.J. , de Castro José Adilson , Fonseca Maria Cindra , Chuvas T.C. , Campos M.A. , Padovese Linilsson Rodrigues
Published: August 2016

Residual stresses typically are generated during the manufacturing process of mechanical components. The non-destructive techniques are quite sensitive to these residual stresses, and to microstructural changes resulting from thermal cycling. In this work, samples of API 5L X80 steel were exposed to several conditions of cooling, under water, air and oil, thus obtaining different microstructures and different levels of residual stresses. The residual stress measurements were made using the methods of Magnetic Barkhausen Noise and X-ray diffraction.
Evaluation of Residual Stresses in Welded ASTM A36 Structural Steel by Metal Active Gas (MAG) Welding Process
Authors: Correa Sandro Rosa , de Campos Marcos Flavio , Marcelo C.J. , de Castro José Adilson , Fonseca Maria Cindra , Chuvas T.C. , Campos M.A. , Padovese Linilsson Rodrigues
Published: August 2016

The use of structural steel in the industry is increasing every day, and the study of stress state after welding has been shown to be of great importance. Nondestructive techniques become quite appropriate to be performed before and during the service component of welded, and thus ensure its integrity. The magnetic technique to be nondestructive, and easy to apply in the field, has potential to be an inspection tool for measuring residual stresses and other microstructural parameters. In this work it was possible to analyze the state of residual stresses through nondestructive techniques, Magnetic Barkhausen Noise and X-ray Diffraction, as well as the semi-destructive technique, high speed hole drilling method, and thereby determine the residual stresses in ASTM A36 steel plate welded by MAG (Metal Active Gas) process.
Preparation and Melting of Zr-1.0Nb Alloy
Authors: Souza Armando Cirilo , Rossi J.L. , Tsakiropoulos P. , Martinez L.G. , Grandini Carlos Roberto , Ceoni F.C. , Mucsi C.S. , Correa H.P.S.
Published: August 2016

Zirconium alloys have many applications in industry in services too harsh for stainless steels, nickel alloys or where a noteworthy improvement in service life may be achieved, by choosing zirconium alloys instead of other metals, such as high permeability to thermal neutrons and excellent corrosion resistance in nuclear reactor environments. Mixing alloying elements, such as niobium, molybdenum, tin, titanium and tantalum, with zirconium changes its physical and chemical properties, especially its resistance to corrosion. In this study, specimens of Zr-1.0Nb alloy were obtained by melting in a furnace with non-consumable electrodes in argon atmosphere. Different samples were prepared to ensure good homogeneity of the specimens. The melting procedure was tested several times to determine the parameters that ensure proper alloy handling. These parameters include the melting point of the alloys under pressure and the current in the furnace. Using the derived melting parameters and processing parameters, it has been obtained Zr-1.0Nb alloy specimens with appropriate homogeneity, as confirmed by auxiliary characterization techniques, such as optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. For these methods, the requirements for physicochemical properties in the nuclear sector were incorporated into the analyses.
Shape Anisotropy as Coercivity Mechanism
Authors: de Campos Marcos Flavio
Published: August 2016

The Alnico magnets (also called Ticonal) have coercivity attributed to shape anisotropy. The conditions for appearing this type of anisotropy are discussed, and the principal is the existence of elongated grains parallel to the easy magnetization axis. A very important detail is that the conditions assumed in the Stoner Wohlfarth model have to be obeyed. The assumptions are i) ferromagnetic phase with single domain particle size and ii) grains without magnetic interaction between them, magnetically insulated by a grain boundary paramagnetic phase. In Alnico magnets, the coercivity mechanism is coherent rotation of single domain size particles.
Perspectives for the Brazilian Industry of Rare-Earth Magnets
Authors: de Campos Marcos Flavio , Rodrigues Daniel , de Castro José Adilson
Published: August 2016

The Brazilian reserves of rare earths were updated. Brazil is among the countries with the largest reserves of rare earths in the world. Rare earths present a series of applications in the high technology industry. Magnet production is one of the applications requesting largest volumes of rare earths. Another relevant application is catalysis and Petrobras needs 1000 tons/year of La2O3 for petroleum refining. CBMM mine has a pilot plant able to produce tons of separated rare earth oxides, notably didymium (a mixing of Nd and Pr oxides) used in magnet manufacture. Serra Verde mine in Goiás also produced separated rare earth oxides. The magnet production in Brazil can be important for the high efficiency electrical motors industry and also for the automotive industry.
The Influence of High Gravity in PbSn Eutectic Alloy
Authors: Freitas Filipe Estevão , Toledo Rafael Cardoso , Poli A.K.S. , An Chen Y. , Bandeira Irajá Newton
Published: August 2016

The study of materials processed in centrifuges improves the understanding of the acceleration influence in the convection behavior in materials processing. This work aims to study the influence of high gravity in PbSn eutectic alloy solidification using a small centrifuge designed and built in the Associate Laboratory of Sensors and Materials of the Brazilian Space Research Institute (LAS/INPE). The samples were analyzed by densitometry and scanning electron microscopy (SEM).
Evaluation of Green Corrosion Inhibitors for Applying in Food Packaging
Authors: Roque Valeska Rodrigues , Roquete Ana Paula Jardim , Martins Fonseca Laura , Mossmann Anelise , Luiz Carla Daniela Cordeiro , Graciela Maldaner , Pavan Flávio André , Galio Alexandre Ferreira
Published: August 2016

In this study, the inhibitor effect of Solidago chilensis extract as green corrosion inhibitor for anodized aluminum alloy samples was evaluated in NaCl 3%wt solution. This study was carried out for application on cans for pack of foods. The procedure of the surface treatment of the samples was done by anodizing followed by sealing in a solution containing the inhibitor. Essays of potentiostatic polarization and electrochemical impedance spectroscopy were done to evaluate the inhibitor effect. The mechanical analyses were performed on anodized samples to evaluate the influence of the thickness of anodization on the mechanical resistance of the samples. The potentiostatic essays indicated that a cathodic inhibitor effect occurs only in non-anodized samples and that the anodic effect of the inhibitor not appears on the anodized samples. The calculated efficiency of the inhibitor was 96 %. The EIS results indicated that the higher values of polarization resistance (16 kΩ) occur on anodized samples containing inhibitor after 72 hours of immersion in NaCl 3%wt. The mechanical essays indicated a non – significant difference between anodized and non – anodized samples.
Characterization of AISI 316L Stainless Steel Pattern via DC Plasma Nitriding
Authors: Kleinjohann Keila Christina , Borges Ramos Bruno , Bernardelli Euclides Alexandre , Maliska Ana Maria
Published: August 2016

Aiming to produce a pattern on the surface of austenitic stainless steel, AISI 316L, cylindrical samples were plasma nitrided with copper grids (the same are used in Transmission Electron Microscopy (TEM)) accommodated on the surface. Samples were positioned at the cathode and process was performed according to following constant parameters: temperature of 400 °C, pressure of 3 Torr and treatment time of 2h. In order to evaluate the difference in the pattern produced, three different gas mixtures were used: poor in nitrogen (5% N2/95% H2), rich in nitrogen (95% N2/5% H2) and a gas mixture with addition of argon (80% N2/10% H2/10% Ar). After nitriding, samples were characterized by optical interferometry (OI), scanning electron microscopy (SEM), optical microscopy (OM), micro hardness test and, X-ray diffraction (XRD). The results showed the presence of a mask (TEM grid) promotes the surface patterning of steel. This patterning is associated with high residual compressive stress induced by the introduction of a large amount of nitrogen.
Development of Coating to Metallic Surfaces with Capacitive Capabilities for Applications in Electronics
Authors: Roquete Ana Paula Jardim , Roque Valeska Rodrigues , Fonseca Laura Martins , Viana Lorena Aparecida Nunes , Henkes Angélica Karine , Galio Alexandre Ferreira
Published: August 2016

The capacitive properties on aluminum alloy coated by sol-gel are evaluated in this work. The samples were anodized in a H2SO4 solution for three different times (15, 20 and 30 min) and subsequently covered by a sol-gel. The capacitance of the samples was evaluated by electrochemical impedance spectroscopy (EIS). Firstly the capacitance of the anodizing samples was evaluated. The second condition was the evaluation of the anodized samples coated by sol-gel. The better capacitance results obtained in the first condition was observed in the blank samples and by the 15 min anodized samples. After the sol-gel deposition, the influence of coating on the overall capacitance was observed. Their stability during the immersion time of the evaluation was observed as well.
Structural Changes in TiO2 Films Formed by Anodizing of Electro-Polished Titanium
Authors: López Díaz Patricia , Pereira Marinalda Claudete , Codaro Eduardo Norberto , Acciari Heloisa Andréa
Published: August 2016

Anodizing is a surface modification technique that is applied to growing oxide films on Ti to accelerate the osseointegration of an implant. Besides the surface roughness, the crystalline structure of these films can affect its performance as a biomaterial. For this reason, this technique has been refined to produce crystalline films without requiring heat treatments. For this purpose, TiO2 films were grown on Ti (grade 2) by anodizing with direct current at different potentials. Images obtained by optical microscopy with polarized light revealed a granular microstructure in various colors, as consequence of different crystalline orientations of the grains and films thickness. Raman spectroscopy showed that the films crystallinity is affected by variations in the applied potential and anodizing time.
Corrosion by Sulfate Reducing Bacteria in Welded Joints of Stell API 5L X80
Authors: Vasconcelos E.S.L. , de Oliveira Edkarlla Sousa Dantas , Lima M.A.G.A. , Montoya M. , Gonzalez Cezar Henrique , Urtiga Filho Severino Leopoldino
Published: August 2016

Articles report that the sulphate reducing bacteria (SRB) are the main micro-organisms related to cases of corrosion. They reduce the sulfate ion resulting in the production of sulfide, disulfide and hydrogen sulfide, potential agents of corrosion of ferrous materials. This study investigated the action of sulfate-reducing bacteria on corrosion test specimens with welded joint of API 5L X80 steel in the presence of seawater. The samples were exposed to sea and sterilized water was then added to BRS. Microorganisms were quantified periodically calculated the corrosion rate and weight loss, and the surfaces of the samples analyzed by light microscopy.
Obtaining and Characterization of Zirconium and Cerium Coatings
Authors: Berbel Larissa Oliveira , Matos Larissa Aparecida Corrêa , Sochodolak Paulo Vitor , Schlindwein Claudia , Rodrigues Paulo Rogério Pinto , Banczek Everson do Prado
Published: August 2016

Some metals prior to receiving a layer of paint should be submitted to a treatment of metal surface, since they are subjected to corrosion. This work aims the obtaining and characterization of a coating based on ceramics of cerium and / or zirconium for metal surfaces treatment. The ceramics were obtained by immersing the aluminum alloy 3003 and the carbon steel (SAE 1010) in the polymeric resin of citric acid and ethylene glycol according to the Pechini method. The characterization of the samples was performed using the following techniques: scanning electron microscopy (SEM), open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and Potentiodynamic Anodic Polarization (PAP). It was confirmed that the coatings of cerium and / or zirconium presented themselves as promise in the treatment of metal surfaces, because both showed good resistance, protecting the metal from corrosion.
Attapulgite Performance in the Degradation of the Yellow Bright Dye
Authors: Almeida Layane Rodrigues , Souza João Sammy Nery , Silva Filho Edson Cavalcanti , Osajima Josy Anteveli
Published: August 2016

Degradation of yellow bright anionic dye under ultraviolet radiation was studied using attapulgite (ATT) as a support in the immobilization of the photocatalyst semiconductor, titanium dioxide, TiO2. The photocatalytic performance of the corresponding catalyst was evaluated using the 1.0x10-4 mol L-1 concentration of the dye. The samples were irradiated with UV light for 120 minutes. The kinetics were monitored by UV-Vis spectrophotometry. The spectra absorption showed that the increased amount of photoactive material in the reaction system maximizes the efficiency of the photocatalytic process.
Photocatalysis of Coomassie Brilliant Blue Using Clay Mineral
Authors: Almeida Layane Rodrigues , Souza João Sammy Nery , Silva Filho Edson Cavalcanti , Osajima Josy Anteveli
Published: August 2016

The presence of organic pollutants, which cannot be eliminated by conventional processes of primary and secondary treatment, can be problematic. Photocatalytic processes offer an efficient breakdown of organic pollutants into non-toxic compounds such as CO2 and H2O. This paper proposes the use of the titanium dioxide embedded in palygorskite as a photoactive material in the degradation of cationic dye, Coomassie Brilliant Blue. The system was irradiated using UV light for a maximum time of 120 minutes. The concentration of the dye used was 1.0x10-4 mol L-1 in 0.5 g L-1 of the photoactive material. The kinetics of the system was monitored by UV-Vis spectrophotometry. In 120 minutes of radiation, the process of photocatalysis reduced the initial concentration of the Coomassie Brilliant Blue dye in half.
Incorporation of Zirconium Oxide on the Surface of Palygorskite Clay for Photodegradation of Industrial Dye
Authors: Miranda Maicon Oliveira , de Araújo Francisca Pereira , Osajima Josy Anteveli , Silva Filho Edson Cavalcanti
Published: August 2016

The palygorskite or attapulgite is a mineral clay of fibrous habits, a phyllosilicate 2:1, presented by the formula Mg5[Si8O20](OH)2(OH2)4.4H2O. Taking advantage of this natural resource available in the State of Piauí, this research aims at incorporating the zirconium oxide to the surface of this clay, through the sol-gel method, in order to evaluate the photoactivity of the composite. The material was characterized by the X-ray diffractometry (XRD), indicating the presence of the zirconium oxide, with the emergence of peaks in 30.8° and 60.9°. It was observed the incorporation of zirconium on the clay by transmission electron microscopy (TEM) and verified the fibrous habit and the presence of ZrO2 on the surface of the clay with 1.35% of incorporated zirconium and 127.4 m2 g-1. The rate of degradation of the Remazol Blue dye was 93.5% when using the composite.
Ga2O3-Doped ZnO-Nb2O5-TiO2 Dielectric Resonators for Terrestrial and Space Telecommunications Applications
Authors: Nono Maria do Carmo de Andrade , Castro Pedro José , Rangel E.G.L. , Mineiro Sergio Luiz
Published: August 2016

Dielectric ceramics find application as dielectric resonators (DRs) in communications systems operating at microwave frequencies. RDs for this application require a unique set of properties: high value of the dielectric constant, low dielectric loss and high frequency stability. This paper presents an investigation of the correlation between the dielectric properties, the characteristics of microstructure and the crystalline phases of Ga2O3-doped ZnO-Nb2O5-TiO2 ceramic system. The ceramics sintered at 1200 °C were characterized as for density, crystalline phases, microstructure and microwave dielectric properties. The results showed that these dielectric ceramics, obtained from the TiO2 anatase crystalline structure, present dielectric constant and quality factor (Q) values appropriate for their use as dielectric resonators in microwave circuits. According to the experiments, as the gallium doping has raised, the dielectric constant increased, the Q factor decreased and the temperature coefficient had a tendency to decrease to a certain extent.
Ion Exchange in Sodium Titanate Nanoribbons and its Application in Dye Photodegradation of Remazol Blue
Authors: Costa Ludyane Nascimento , Nobre Francisco Xavier , Neto Bartolomeu Cruz Viana , de Matos José Milton Elias
Published: August 2016

This work addresses the main point, the synthesis of one-dimensional titanate nanostructures and their ion exchange with transition metals for application in photocatalysis. The catalysts tested in the photocatalytic process were titanate nanoribbons (NRTi) synthesized by hydrothermal method and ion exchanged with Sn2+. The structural and morphological analysis of the material was performed by XRD, Raman spectroscopy and TEM images, confirming the formation of the desired structures and the growth of SnO2 nanoparticles after the ion exchange process with average size smaller than 10 nm. The values of surface area were obtained by BET and showed a significant increment after the ion exchange process, making it favorable for application in photocatalysis. The NRTi was applied in the degradation of blue dye remazol, generating a total degradation in 120 minutes. The rate constants were calculated from the pseudo-first-order equation.
Influence of the Addition of Inorganic Salt in Obtaining Hybrid Membranes
Authors: Medeiros Keila Machado , Lima Diego Farias , de Lima Carlos Antônio Pereira , Araújo Edcleide Maria , Lira Hélio Lucena , da Paz Renê Anísio
Published: August 2016

The membrane separation processes have low power consumption, higher separation efficiency, simplicity of operation and high quality end product. In this work, hybrid membranes of polyamide6 with bentonite clay were obtained by adding an inorganic salt. The hybrids were obtained by the melt intercalation method. The membranes were prepared by phase inversion technique by varying the percentage of inorganic salt and the time of exposure of the membranes during the immersion-precipitation process. The hybrid and hybrid membranes with and without the addition of the inorganic salt were characterized by X-ray diffraction (XRD). The results from XRD showed that the hybrid and hybrid membranes with and without inorganic salt presented an exfoliated and/or partially exfoliated structure. The addition of the inorganic salt did not cause significant changes with respect to the crystalline behavior of the polymer under study.
Electrochemical Behavior of Electroactive PVS/PANI Films Containing Chemically Modified Cellulose
Authors: Teixeira Paulo Ronaldo Sousa , Teixeira Ana Siqueira do N. Marreiro , Teixeira da Silva José Regilmar , Farias Emanuel Airton de Oliveira , Dionisio Natália de Araujo , Silva Filho Edson Cavalcanti , Eiras Carla
Published: August 2016

Electroactive films containing cellulose modified with cationic and anionic groups were prepared with polyaniline (PANI) and poly (vinyl sulfonic acid) (PVS). The modifications were performed with (aminomethyl) pyridine (AMP), ethylenediamine (EDA), buthylenediamine (BN), bis-(aminopropyl) piperazine (APP), maleic anhydride (MA), and phosphate PO43- groups. The films were prepared using the layer-by-layer (LbL) technique, utilizing dispersed cellulose in a PANI solution forming the PVS/PANI system (cationic or anionic cellulose). Films of unmodified microcrystalline cellulose (MC) were also prepared for comparison. The films were characterized by cyclic voltammetry. The electrochemical responses of PANI present in the film, especially in terms of current density and redox potential, were found to be influenced by the modification of the cellulose.
Photosensitized Polystyrene Film for Dye TX under Different Radiation Sources
Authors: Osajima Josy Anteveli , Schmitt Cavalheiro Carla Cristina , Neumann Miguel Guillermo
Published: August 2016

The polystyrene (PS) has a variety of applications. Many mechanisms have been proposed for the degradation of the polymer, but a consistent mechanism does not exist yet in the literature due to the complexity of the kinetics and formation of photoproducts that depend on various conditions photodegradation. The aim of this study was to investigate the kinetic behavior of the photodegradation of PS films photosensitized by thioxanthone (TX) under UV, Vis and xenon radiation. Changes in chemical structure caused by photo-oxidation in the films were verified by FT-IR. The photodegradation of polystyrene films sensitized by thioxanthone showed greater efficiency in the formation of carbonyl group under Vis radiation and xenon when compared to pure PS. However, in the ultraviolet films system PS and PS / TX exhibited similar kinetic behavior.
Influence of Content and Treatment of Clay in the Morphology of PES Membranes
Authors: Nóbrega Medeiros Vanessa , de Carvalho Thamyres Cardoso , Leite Amanda Melissa Damião , Araújo Edcleide Maria , da Paz Renê Anísio , Lira Hélio Lucena
Published: August 2016

Polymeric membranes were produced from the nanocomposites of polyethersulfone and clay (untreated-MMT and treatment-OMMT), by phase inversion technique, in the proportions of 3 and 5% w/w, using as the solvent N, N dimethylformamide (DMF). From XRD results it was noted a change in the structure of the MMT by organophilization process with increase of the interplanar basal distance. To the membranes it was observed an exfoliated and/or partially exfoliated structure. From SEM images the nanocomposite membranes showed a surface apparently exempt of pores, however in the cross-section images shows an anisotropic structure, where the skin is dense and the porous support displays macrovoids. By the flow measurement, it was found that the compositions presented the same tendency in the flow lines, where the flow is high on the beginning and drops over time; and the inclusion of clay increases the flow, especially to the membranes with MMT 5%.
Morphological Evaluation of Chitosan/Curcumin Beads and Powder: Effect of the Methanol as a Solvent
Authors: Costa da Silva Milena , Leite Michele Dayane Rodrigues , Lima Oliveira Suelem Sonaly , Fideles Thiago Bizerra , Fook Marcus Vinícius Lia
Published: August 2016

Curcumin is a polyphenolic component of Curcuma longa, highlighting in the literature by presenting medicinal properties such as: antioxidant, anti-inflammatory, antibacterial, antiparasitic, antimalarial and anticancer activities. From this, it has been used together with curcumin, chitosan, a biodegradable polymer of natural origin, in order to encapsulate curcumin from a polymer system. Thus, this study aimed to evaluate the morphological behavior of beads and powder chitosan/curcumin, by the Optical Microscopy (OM) technique in the presence of the solvent (methanol). From the pictures, it was noticed that the beads have in their external structure the presence of the drug in a punctual manner, but a more homogeneous internal region. Regarding the powder, it was observed that curcumin was well distributed and involved by chitosan, proving the good interaction between them. In the presence of the solvent, the beads and the powder showed a good distribution of curcumin.
β-TCP Produced through the Starch Consolidation Technique
Authors: Gondim T.N. , Maestrelli Sylma Carvalho , Campos Maria Gabriela Nogueira , Minucci Marília Zani , Marques Rodrigo Fernando Costa , Fernandes R.S.
Published: August 2016

Synthetic materials based on calcium such as hydroxyapatite and beta-TCP are one of the main bone substitutes because of their biocompatibility. The starch consolidation is a simple and low cost technique which is based on using the starch as a gel former in the presence of water, turning possible its use as a conforming and main element to form pores. In this project,samples were produced trough starch conformation by fixing the percentage of solids (beta-TCP) in 50% and varying the amount and type of starch (corn and potato) in 10, 20, 30 and 40%. The results showed that it was possible to obtain porous samples by using corn and potato starches. Moreover, the percentage of starch added strongly influenced porosity and resistance of the samples. The addition of 30% or more of starch reduced the mechanical resistance of samples which limited their use.
Surface Modification of the Alloy Ti-7.5Mo by Anodization for Biomedical Applications
Authors: do Amaral Escada Ana Lucia , Muñoz Chaves Javier Andres , Rosifini Alves Claro Ana Paula
Published: August 2016

The purpose of this study was to evaluate the TiO2 nanotubes growth and the variation in its diameter to improve the surface properties of Ti-7.5Mo to use for biomedical applications. For the nanotubes TiO2 growth, the samples were anodized in glycerol and ammonium fluoride and divided according to the anodizing potential at 5V to 10V and 24 hour time. The surfaces were examined by scanning electron microscope (SEM), X-ray analysis (XRD) and contact angle measurements. The average tube diameter, ranging in size from 13 to 23 nm, was found to increase with increasing anodizing voltage. It was also observed a decrease in contact angle in accordance with the increase in the anodizing potential. The X-ray analysis showed the presence of anatase phase in samples whose potential was 10V and this condition represents a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.
Nanotubes Growth on Ti-15Mo Alloys by Anodization at Low Voltage
Authors: Rangel André Luiz Reis , Moreira Santos Guilherme Rogeri , Rosifini Alves Claro Ana Paula
Published: August 2016

Surface modification by nanotubes growth is an efficient technique to improve the interaction between implant and biological environment. Several studies indicate who low voltages anodizations are able to generate nanotubes with smaller diameters, positive characteristic for the post-implantation cell growth. The aim of this study was to characterize the morphology of the nanotubes formed on Ti-15Mo surfaces applying 5 or 10 V as anodizing voltage. For both conditions were used glycerol based electrolyte with ammonium fluoride and the anodization time was 24 hours. The samples were cleaned in an ultrasonic bath and annealed at 450 ° for 1 hour after anodization. In order to characterize the surfaces were performed scanning electron microscopy images, contact angle measurements and X-ray diffraction analysis. The results confirmed the formation of nanotubes evenly distributed on the surfaces and a direct relation between anodizing voltage and nanotubes diameters.
Surface Modification of Ti-30Ta Alloy by Electrospun PCL Deposition
Authors: Wada Cristiane Mayumi , Rangel André Luiz Reis , de Souza Marisa Aparecida , Almeida Rosemeire dos Santos , D’Ávila Marcos Akira , Rosifini Alves Claro Ana Paula , Rosifini Alves Rezende Maria Cristina
Published: August 2016

In this study, PCL electrospun fibers were deposited on the Ti-30Ta alloy for change the surface properties. Experimental Ti-30Ta alloy was obtained by melting titanium and tantalum in arc melting furnace with argon atmosphere. Ingots were homogenized and bars with 10 mm of diameter were obtained in rotative swagging. PCL fibers were deposited on disks of the alloy by electrospinning. Plasma treatment was carried out for change PCL electrospun superficial energy by using stainless steel plasma reactor. Samples were immersed in mineralization solution for apatite growth. Surfaces were evaluated by using SEM, X-rays diffraction and contact angle. Samples exhibited hydrophilic behavior after plasma treatment and mineralization. Results are very interesting for biomedical applications.
Biocidal Glasses with High Performance: Comparison of the Antimicrobial Action Obtained by Use of Different Metal Ions
Authors: Riss H. , Testa K. , Betiatto K. , Mendes Elton , Piletti R. , Fiori Márcio Antônio , Riella Humberto Gracher
Published: August 2016

The development of antimicrobial materials and its use have shown an effective way to reduce the risks posed to human life by fungi, bacteria and other pathogenic microorganisms. This work presents preliminary results about the development of powder biocidal vitreous, applying the ionic exchange process between the sodium ions, present in the glass matrix, and ionic oligodynamic species, present in the ionic exchange medium. The magnitude of the oligodynamic effect was modified with the use of different metal ions, providing significant difference in antimicrobial performance. Three samples were prepared incorporating different ionic metal in its glass matrix during the ionic exchange process, Ag+, Zn2+ and Cu2+. These precursors of cations were used: AgNO3 for the silver ions, ZnSO4 for the zinc ions and Cu (NO3)2 for the cooper ions. Samples were submitted to microbiological analysis – Agar Diffusion Test for Escherichiacoli and Staphylococcusaureus bacterial species, and fungus species Candidaalbicans – and atomic absorption techniques. Results showed higher microbiological magnitude to the silver-glass, followed by the cooper-glass and zinc-glass.
Different Synthesis Routes for Hydroxyapatite Nanoparticles by Mechanical Stirring
Authors: Lunz Juliana do Nascimento , Licona Karla Patricia Macedo , Ribeiro Alexandre Antunes , Delgado José Angel , Alonso Lizette Morejón , de Oliveira Marize Varella
Published: August 2016

Nanosized hydroxyapatite (HA) with crystallinity and composition similar to bone apatite has been widely investigated in the last years, due to their excellent biocompatibility in bone replacement applications. This bioceramic can be synthesized by many wet chemical and mechanochemical methods. In this paper, nanosized hydroxyapatite powders were synthesized by two wet chemical routes using mechanical stirring method. The first route was used for HA synthesis from CaCl2.2H2O and Na3PO4.12H2O solutions and the second route was from Ca (OH)2 and H3PO4 solutions. The synthesized HA nanoparticles were characterized by Dynamic Light Scattering, BET Surface Area analysis, X-ray Diffraction, Infrared Spectroscopy, chemical analysis and Scanning Electron Microscopy. The results indicated that HA nanoparticles were successfully synthesized by both wet chemical precipitation routes and all powders presented a Ca/P ratio similar to stoichiometric HA, nanoneedles morphology and single HA crystalline phase.
A Study of the Mechanical Behavior of Concrete Using Additive and Waste Tires Rubber through a Diametral Compression Test Using Digital Image Correlation
Authors: Rosendo Sobrinho Francisco , da Silva Jr. Francisco Alves , de Codes Rodrigo Nogueira
Published: August 2016

Concrete is very resistant to compression, although its tensile strength is limited and it is regarded as a brittle material. One way to overcome this problem is through the use of plasticizing additives, as well as the introduction of fibers in the cement matrix. The aim of this study is to determine changes in the mechanical tensile strength of concrete when substitutes are found for sand in the form of waste tire rubber, with the introduction of plasticizer additive properties. The analysis was conducted by carrying out a diametral compression test combined with digital image correlation to measure the displacement and strain fields obtained with the applied loads. It was observed from the stress and strain values obtained in these tests that there is a reduction in tensile strength. This is accompanied by an increase in composite deformability and a rise in the percentage of waste.
Synthesis of ZnO Nanoparticles Doped with Cobalt: Influence of Doping on the Magnetic and Fluorescent Properties
Authors: Sugahara Henrique J. , de Melo Etelino F. , de Melo Celso P. , Alves Kleber G.B.
Published: August 2016

We have investigated the influence of cobalt doping on the luminescent and magnetic properties of ZnO nanoparticles prepared by co-precipitation. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and by use of a vibrating sample magnetometer (VSM). XRD analyses revealed a standard ZnO wurtzite crystal structure and showed that the cobalt doped ZnO nanoparticles (ZnO:Co_NPs) were synthetized without impurities. The calculation based on the XRD shows the average crystallite sizes of ZnO to be in the 8-11 nm range. TEM images of ZnO and ZnO:Co indicated that these nanoparticles are nearly uniformly spherical with a diameter of about 10 - 15 nm. The PL spectra exhibited high [low] intensity in the UV [visible] region. While the PL shows a decreasing intensity with increasing doping doses, the peak at 544nm is not present in the cobalt-doped zinc oxide, and a the peak at 378 nm shifts to 390nm. The VSM measurement confirmed the presence of ferromagnetism and we observed an increase in the values of the saturation magnetization with increasing Co concentration.
Effects of Solvent and Concentration of Borohydride for the Preparation of PtRu/C Electrocatalysts for Direct Methanol Fuel Cell Anodes - A Factorial Design Study
Authors: Polanco Nataly Soares de Oliveira , Tusi Marcelo Marques , Brandalise Michele , Oliveira Neto Almir , Spinacé Estevam Vitorio
Published: August 2016

A factorial design study was performed to evaluate the influence of the BH4-:PtRu molar ratio (5 and 15) and the solvent (water or isopropyl alcohol) in the preparation of PtRu/C electrocatalysts for Direct Methanol Fuel Cell (DMFC) anodes. The obtained materials were characterized by Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM). For both solvents increasing the BH4-:PtRu molar ratio from 5 to 15 leads to a decrease of the mean nanoparticle sizes and, using water as solvent, it was observed better distributions of the nanoparticles on the carbon support than using isopropyl alcohol. The DMFC maximum power density was obtained using a electrocatalyst prepared with a BH4-:PtRu molar ratio of 15 and water as solvent. The analysis of the effect of interaction of the two parameters showed that the variations of the maximum power density was more dependent of the BH4-:PtRu molar ratio than of the solvent used.
Developing a regulatory framework for the financial, management performance and social reporting systems for co-operatives in developing countries: A case study of South Africa
Authors: Nieman Gideon , Fouché Karel
Published: August 2016

Purpose: This report is on a team effort to advise the Department of Trade and Industry on the development of a regulatory framework for the auditing of Financial, Management. Performance and Social Reporting Systems for co-operatives. Orientation: There was no framework in place prescribing requirements for reporting on financial, management and social performance of co-operatives. As a result, the team assisted the Department of Trade and Industry with the development of a proposed reporting framework with reference to international best practices and existing financial reporting frameworks. Findings: The research performed showed that existing reporting frameworks and practices do not meet the reporting requirements of co-operatives in all aspects because of the different nature of co-operatives as opposed to shareholder-owned entities.
The challenges facing the Dutch Reformed Churches in the South African liberal democracy
Authors: Sekhaulelo Motshine A.
Published: August 2016

This article investigates the challenges facing the Dutch Reformed Churches in the SouthAfrican liberal democracy. It is premised on the fact that the Dutch Reformed Churches areconfronted with a new context that places the church in a position to continue its work ofbearing witness in the new dispensation. Part of this reflection involved seeking out theBiblical principles and guidelines that Christians would have to take into account in associationwith the new political order.
The poor in the Psalms and in Tsepo Tshola’s song Indlala: African liberationist remarks
Authors: Mtshiselwa V. Ndikhokele N.
Published: August 2016

This article sets out to investigate how an African liberationist paradigm could be used in South Africa as a theoretical framework that shapes an inquiry into the issue of poverty in the Book of Psalms. The poor in the Davidic collections of psalms (cf. Ps 10; 23, 72; 109) will therefore be examined within the South African context in order to probe the liberating possibilities that the psalms could offer to poor black South Africans, and most importantly when the text is read in dialogue with Tsepo Tshola’s liberationist song Indlala [Starvation]. Firstly, this article discusses an African liberationist paradigm with the view to anchor the reading of psalms within a theoretical framework. Secondly, within that framework, this article uses the song Indlala as a hermeneutical tool to unlock the reality of poverty in South Africa. Thirdly, guided by an African liberationist framework the article teases out th ecategories and voices of the poor in the psalms. In the end, this article argues that the reading of poor in the Psalms, particularly with an African liberationist lens could have liberating implications for poor black South Africans.
The refugee dilemma and migrant crisis: ‘Charity begins at Home’ or ‘Being Home to the Homeless’? The paradoxical stance in pastoral caregiving and the infiltration and perichoresis of compassion
Authors: Louw Daniel
Published: August 2016

The current refugee and migrant crisis is revealing on a deeper ‘spiritual level’ a crisis of meaning and habitus (attitudinal crisis). Because of prejudice, xenophobia reveals a crisis of compassion and diaconic outreach. How should local communities and communities of faith display hospitality (xenophilia) to the other (stranger, foreigner, outsider) in cases where one’s own life is threatened by those you are supposed to care for? Is it true that charity begins at home, or is charity, as determined by the Christian notions of ḥesed and oiktirmos, an inclusive concept that should or could start with the homeless, the outcast and the outsider as well? This question points to the danger of selective compassion. It is argued that pastoral caregiving, within the refugee and migrant dilemma, should apply a hermeneutics of complexity and paradox. In this regard the theological paradox of the passion (pathē) of Christ should be implied in order to make room (perichoresis) for displaced and homeless people. The theological argument is based on the following presupposition: the passio dei defines ‘practice’ in pastoral theology as compassionate hospitality, as a mode of being-with, that eventually should infiltrate and penetrate the systemic paranoia of prejudice, as well as the networking dynamics of human relationships, irrespective of race, class and gender distinctions.
Was Paul fully Torah observant according to Acts?
Authors: Du Toit Philip La G.
Published: August 2016

This article primarily examines the question if the Acts of the Apostles portrays Paul as being fullyTorah observant. This question secondarily coheres with the question if it can be derived fromActs whether it was expected of all Christ-believers from the loudaioi to fully adhere to the Torah,or that such a belief was universal in the early church. The conclusions on all of these questions arenegative. These conclusions are reached by way of analysing these claims against the text of Acts(mainly 15:1–35; 16:3; 18:18; 21:17–26; 21:39; 22:3, 23:6 and 26:5) in comparison with the principlePaul laid out in 1 Corinthians 9:19–23 to be everything to everyone. The latter principle is foundto be compatible with the narrative in Acts, although the difference in the approaches of Luke andPaul is acknowledged, especially in terms of their portrayal of the Mosaic Law.
Ecological ethics and creation faith
Authors: Körtner Ulrich
Published: August 2016

Over past decades a concept of ecological ethics has taken root, which is often equated with environmental ethics. Church and theology have also responded to the environmental crisis. In the last third of the past century an intense discourse about the concerns and extent of a so called creation ethics was conducted. In connection with the question of a creation ethics, and the global responsibility of humans for the biosphere of our planet, the topic of creation has also gained new attention in dogmatics. In this way, ecology has also become a topic of systematic theology. The article focuses on the debate in the German speaking context. Occasionally, a quasi-religious elevation of ecology to the status of a doctrine of salvation is observable. Because theology always also has a function of critique of religion, it must also critically engage the sometimes open and sometimes hidden religious contents and claims of eco-ethical concepts. For this purpose, the first step of the present contribution is to more precisely determine the concepts of creation and nature. Thereafter, the problem of anthropocentrism is analysed. In a further step, the concept of sustainability is analysed. In conclusion, the main features of a responsibility-ethics model of ecological ethics are outlined.
The theory–practice distinction and the complexity of practical knowledge
Authors: Miller-McLemore Bonnie
Published: August 2016

Over the past few decades, theologians have recognised the value of practice but have been optimistic about the ease with which practice is incorporated into theology. People use all sorts of adjectives to characterise the complex relationship – ‘integrally related’, a ‘deeper reciprocity’, ‘bound up in thickly intertwined ways’ – but connecting the two is not as easy as these words suggest. This article returns to the age-old question about the relationship between theory and practice. But it studies this question from the angle of practice. Although many scholars have analysed the distinction between theory and practice as it functions conceptually, few have examined challenges in relating the two as they emerge in practice. The article argues that there is an inevitable distinction between theory and practice that receives considerably less attention and needs more understanding and even respect. It also argues that the discipline of practical theology adds a distinctive angle on this discussion because it considers how the concepts function practically.
A questionnaire survey on diseases and problems affecting sheep and goats in communal farming regions of the Eastern Cape province, South Africa
Authors: Bath Gareth F. , Penrith Mary-Louise , Leask Rhoda
Published: August 2016

A questionnaire of 15 questions was completed by four categories of respondents with the aim of establishing the experience and opinions of these groups on the constraints including animal health problems for communal, small-scale sheep and goat farming in the Eastern Cape province of South Africa. The questionnaires were completed independently and categories were representative of the areas investigated. Analysis of responses was done by means, ranges, votes and clusters of responses. Comparisons between the responses of the four categories were made to identify similarities or contrasts. The results revealed that of non-veterinary concerns, stock theft was the major problem for these farms. Nutrition was a further major constraint. A third area of significant concern was the provision or availability of facilities like fences, water troughs, dips and sheds. Lack of marketing and business skills were also seen as important deficiencies to be rectified so as to promote profitable farming. Of the most important veterinary problems identified, the provision, availability, cost and care of drugs and vaccines were seen as major stumbling blocks to effective disease control, as well as lack of access to veterinary services. The most important diseases that constrain small-ruminant livestock farming in the farming systems investigated were sheep scab and other ectoparasites, heart water, enterotoxaemia, internal parasites and bluetongue. A lack of knowledge in key areas of small-stock farming was revealed and should be rectified by an effective training and support programme to improve the contribution of small-ruminant farming to livelihoods in these communities.