bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Cooling Curves of the Heat Affected Zones of API 5L X80 Steel of Welds Made by Flux Core Arc Welding Self Protecting
Authors: de Lira Heronilton Mendes , Ferreira Ricardo Arthur Sanguinetti , das Neves Maurício David Martins , dos Santos Maurílio José , Urtiga Filho Severino Leopoldino , Araújo Filho Oscar Olimpio
Published: August 2016

The simulation of cooling curves of the heat affected zones (HAZ) of API 5L X80 steel was based on the cooling rates of welds made by the process named FCAW-S (Flux Core Arc Welding Self-Protecting). The specimens were analyzed by macroscopy, light microscopy (LM) and scanning electronic microscopy (SEM) to investigate the effects of cooling conditions on the tensile test and Vickers hardness. A thermo-mechanical simulator showed be able to reproduce the different thermodynamics conditions of points in the HAZ and allowed the reproduction of the thermal cycle obtained by welds were applied to the specimens of API 5l X80 steel. The values of the yield strength, ultimate strength and hardness found in the specimens were lower than those presented by the material as received.
Corrosion Behavior of Fe-Mn-Si-Cr-Ni-Co Shape Memory Stainless Steel in Highly Oxidizing Medium
Authors: della Rovere Carlos Alberto , Silva Rodrigo , Hammer P. , Otubo Jorge , Kuri Sebastião Elias
Published: August 2016

A study was conducted on the corrosion behavior and characteristics of the passive oxide film of Fe-Mn-Si-Cr-Ni-(Co) shape memory stainless steels (SMSS) in a concentrated nitric acid (HNO3) solution, based on potentiodynamic polarization, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. The results indicated that Fe-Mn-Si-Cr-Ni-(Co) SMSSs exhibit a passive behavior similar to that of 304L austenitic stainless steel (304L SS). However, unlike 304L SS, their high silicon (Si) content renders them insensitive to intergranular attack in highly oxidizing environments. The XPS analysis also indicated that Si appears to be the main element responsible for the high protectiveness afforded by the passive film formed on Fe–Mn–Si–Cr–Ni–Co SMSS.
Parameters Evaluation of Bond-Coat Deposited by CO2 Laser Beam for Aeronautical Turbine Blades
Authors: Teleginski Viviane , Santos Júlio César Gomes , Chagas Daniele Cristina , Azevedo Jéssica Fernanda , Costa Oliveira Ana Claudia , de Vasconcelos Getúlio
Published: August 2016

The high temperature environments where aeronautical turbine blades are exposed makes mandatory the use of ceramic coatings. A bond coat comprised by a MCrAlY alloy (M=Co, Ni) is necessary to match the blade metallic substrate with the ceramic, also acting as a corrosion barrier. The laser treatment of metals and alloys is based in the surface local heating, followed by high cooling rates. The laser parameters such as scanning speed and laser power, plays an important role on the morphological, mechanical and chemical characteristics of the deposited material. In the present investigation, the NiCrAlY deposition was performed in stainless steel substrates with a CO2 laser beam. Different laser parameters of scanning speed and number of scanning cycles were implemented. The samples were characterized by optical microscopy and measurements of Vickers hardness. The results show that it is possible to achieve coatings with high hardness, free of pores or any pronounced defects, metallurgically bonded to the substrate.
Zirconium Based Metal Pretreatments: A Characterization Method for Ecologically Sustainable Thin Film Surface Pretreatments
Authors: dos Santos Demetrio Jackson , Tavares Lara Basilio , Salvadori Maria Cecilia
Published: August 2016

Zirconium based metal pretreatments have become widely used in recent years as a substitute for phosphate deposition on steel alloys and for chromate on aluminum alloys in industrial applications. The choice of a zirconium based intermediate layer follows from its ecologic sustainability − decreased water and energy consumption, vehicle weight reduction, and low byproduct generation during processing. Here we describe our investigations of a characterization method of converted metal oxide thin films deposited by a plasma method. The thin film composition was characterized by Rutherford Backscattering Spectroscopy (RBS) and Energy Dispersive Spectroscopy (EDS) before and after conversion by a zirconium-based pretreatment, revealing the formation of zirconia after treatment. The corrosion mechanism of the deposited metal oxide films was investigated using electrochemical analysis, confirming the susceptibility of the film to corrosion and the applicability of corrosion investigations. The results pointed to a better performance of the RBS in comparison to EDS.
Pre-Treatment of Niobium Phosphate for Protection against Carbon Steel Corrosion
Authors: Antunes Jr. Osmar dos Reis , Matos Larissa Aparecida Corrêa , Berbel Larissa Oliveira , Schlindwein Claudia , Sochodolak Paulo Vitor , Rodrigues Paulo Rogério Pinto , Banczek Everson do Prado
Published: August 2016

This work proposes the development of a niobium phosphate coating (PNb) to replace the zinc phosphating, which is very aggressive to the environment and human health. The metallic material utilized was carbon steel (SAE 1010), which was coated with sunbathing - gel containing phosphate and niobium. A traditional zinc phosphate coating was used for comparison of results. The samples were characterized by scanning electron microscopy (SEM), dispersive energy spectroscopy (DES), open circuit potential, electrochemical impedance spectroscopy and anodic polarization. The results demonstrated that the samples coated with niobium phosphate have more surface nobility and greater corrosion resistance.
Effect of Argon during Diamond Deposition by Hot Filament Chemical Vapor Deposition
Authors: Barbosa Divani C. , Mengui Ursula Andréia , Baldan Mauricio R. , Trava-Airoldi Vladimir J. , Corat Evaldo José
Published: August 2016

The effect of argon content upon the growth rate and the properties of diamond thin films grown with different grains sizes are explored. An argon-free and argon-rich gas mixture of methane and hydrogen is used in a hot filament chemical vapor deposition reactor. Characterization of the films is accomplished by scanning electron microscopy, Raman spectroscopy and high-resolution x-ray diffraction. An extensive comparison of the growth rate values and films morphologies obtained in this study with those found in the literature suggests that there are distinct common trends for microcrystalline and nanocrystalline diamond growth, despite a large variation in the gas mixture composition. Included is a discussion of the possible reasons for these observations.
Sorption of Bright Yellow Dyes by Filter Papers
Authors: de Araujo Braz Elton Marks , Rosa Mirna Sales Loiola , Santos Maria Rita de Morais Chaves , Santos Jr. Luiz de Sousa , Osajima Josy Anteveli , Silva Filho Edson Cavalcanti
Published: August 2016

The constant search for the removal of organic and inorganic pollutants has been largely intensified lately, as has the search for efficient techniques. With that, this work aims to test two filter papers of different origins to identify their interaction with the bright yellow dye and to determine the adsorption capacity of each paper. Various parameters were studied (pH, time, temperature, and concentration) and it was possible to verify that the best interaction conditions between the material and the dye were 180 minutes, pH 2, and temperature of 298 K, with a maximal capacity at approximately 7 mg of dye per gram of material, with a kinetic adjustment to the pseudo-second-order model. Thus, these results prove that the paper interacts with the dye, and it can be used as an adsorbent.
Functionalization of Cellulose with Cysteamine: Synthesis, Characterization, and Adsorption
Authors: Bezerra Roosevelt Delano Sousa , Silva Mateus Soares , Ferreira Francisco José Lustosa , Silva Lucinaldo Santos , Osajima Josy Anteveli , Silva Filho Edson Cavalcanti
Published: August 2016

The cellulose matrix was chemically modified with cysteamine (CelCTA) and characterized by elemental analysis, and subsequently applied to the removal of copper ion in an aqueous media. The experimental adsorption isotherm obtained for the studied system was adjusted to linear models: Langmuir, Freundlich, and Temkin. Among the proposed models, the Langmuir model was the one with the best linear adjustment to data obtainedexperimentally, with an adsorption capacity of the adsorbent for 0.3292 mmol dm-3.
Cellulose Phosphate Applied in the Removal of the Drug Acetaminophen from Aqueous Media
Authors: Bezerra Roosevelt Delano Sousa , Morais A.I.S. , Osajima Josy Anteveli , Nunes Lívio César Cunha , Silva Filho Edson Cavalcanti
Published: August 2016

The cellulose phosphate used for this work was obtained by a reaction between cellulose and sodium trimetaphosphate (STMP) at pH 10. The material obtained was characterized by 31P nuclear magnetic resonance (31P NMR) spectrometry and energy-dispersive X-ray spectroscopy (EDS). In the 31P NMR results, the two peaks at 2.05 and 7.96 ppm are related to phosphorous. The EDS indicated the presence of 5.47% of incorporated phosphorus which proved the modification. The material obtained was applied in the removal of the pharmaceutical drug acetaminophen (acetaminophen) from aqueous media. The maximum adsorptions of the drug in the cellulose phosphate was 60.7, 56.7, and 60.0 mg g-1 at the temperatures 298 K, 308 K, and 318 K, respectively, in 120 minutes at pH7. The plot traced from the data best aligns with the pseudo-second order kinetic model and with the physical-chemical model proposed by Freundlich.
Environmental Evaluation of Stabilized and Solidified Products in Brazil: A Review
Authors: Maciel Elenize Ferreira , Brehm Feliciane Andrade , Kulakowski Marlova Piva , Kazmierczak Claudio de Souza
Published: August 2016

The diversity of industrial solid waste has grown exponentially in recent years, requiring waste management strategies focused on the reduction of associated environmental impacts. The solidification/stabilization (S/S) technique is increasingly used in the disposal or recycling of this waste. The Brazilian standard about the leaching of hazardous compounds in waste is being used to evaluate S/S products in their end disposal in landfills, with no description of any protocol to investigate performance during their life cycle, as observed when they are used as admixture to building materials. In this context, this study describes a qualitative review of leaching methods in use to assess S/S products in Brazil, in comparison with the main techniques adopted in other countries.
Application of Palygorskite in Purification Process of Frying Oil
Authors: Araújo Rian Felipe de Melo , Freire Lécia Maria da Silva , Nunes Lívio César Cunha
Published: August 2016

The Brazil produces a million tons of waste oils from frying, annually. Disposal of these usually is done improperly, resulting in serious environmental problems. In this context, the objective was to develop a method for purification of oils used in frying, using palygorskite as an cleansing agent. For this, acid activation and characterization of palygorskite was realized. So, were developed a method for purification of oil, using 23 factorial design as a tool for process optimization. Subsequently, was realized the physicochemical characterization of oils by transesterification followed by GC-MS. The results revealed a significant increase in the adsorption of the clay after acid activation process, while tests of purification of frying oil showed effective improvement of their characteristics, highlighting the disappearance of the smell of rancid oil and bleaching. The results showed that the purification method used was efficient.
Effluent Treatment of Synthetic Tanning by Nanomaterials Photocatalytic
Authors: de Lima Carlos Antônio Pereira , de Lima Geralda Gilvânia Cavalcante , Vieira Fernando Fernandes
Published: August 2016

The industry is one of the most polluting sectors of the aquatic ecosystem. Conventional treatment methods no longer have full effectiveness. The heterogeneous photocatalysis, using TiO2 as the semiconductor (photocatalyst) is one of the most promising techniques for polishing industrial effluents. In the present study determines the best pH range, to optimize the phenomenon of adsorption, and evaluates the reduction of hexavalent chromium and the removal of organic matter in synthetic samples, using a reactor with glass plate impregnated with TiO2 and making use of solar radiation. It was observed that the acidic pH is optimal for the photocatalytic process and that there was a minimum removal efficiency of 62% and 60% for Cr (VI) and organic matter, respectively.
Synthesis and Photocatalytic Evaluation of Nanocrystalline ZnO Obtained by High Energy Milling
Authors: Dias Jeferson Almeida , Arantes Vera Lúcia , Ramos Alfeu Saraiva , Giraldi Tania Regina , Minucci Marília Zani , Toledo Mauro F. , Maestrelli Sylma Carvalho
Published: August 2016

Photocatalytic processes have been applied to treatment of organic effluents through the mineralization of these pollutants on a semiconductor surface. Obtaining nanosemiconductors is desirable for the increasing of particle surface area and improvement in photocatalytic efficiency. In this paper, it was evaluated the influence of High Energy Milling (HEM) as a technique to produce nanocrystalline zinc oxide. The photocatalytic activity of the milled powders to degrade Rhodamine-B dye when exposed to ultraviolet and visible radiation also was investigated. The powders were milled during 4 and 10 hours by dry media milling and 10 hours by wet media milling. The results indicated that there were no detectable powder contamination during the millings and the reduction of crystallite size was function of time and media of milling. All of the assessed samples demonstrate high degradation of the dye, which corroborates with the potentiality of this technique to photocatalysts production. The material milled during 10 hours by dry media milling showed the best results under the experimental conditions.
Effect of Strontium Doping on the Structural, Morphological, and Dielectric Properties of PZT Ceramics
Authors: da Silva Margarete Soares , Dias Rafael Gomes , Souza Eliane F. , Cilense Mário , Zaghete Maria A. , Cavalheiro Alberto A.
Published: August 2016

Strontium-modified lead zirconate titanate ceramics was prepared by the polymeric precursor method. The effect of Pb (II) substitution by Sr (II) in A site of the perovskite structure at molar percentages of 0.0, 0.2, 0.4 and 0.6 mol% was investigated through XRD and Rietveld method. The increasing of strontium amount displaces the morphotropic phase boundary toward to tetragonal phase and that results can be associated to the tetragonal lattice expansion besides the rhombohedral opposite phenomenon. The effect of strontium substitution on the dielectric properties for sintered ceramics is also investigated and showed the strontium substitution leads to reduction of weight loss and increasing of density for sintered ceramic. The Kc and Tc oscillates as function of ceramic morphology and is not possible to verify the existence of conductive intergrains defects by loss tangent curves. An intrinsic event can be occurring because considerable lattice distortion was verified in tetragonal and rhombohedral structures for powder samples.
Mechanical Analysis of Biodegradable Films from Native and Chemically Modified Potato Starches
Authors: Fonseca Laura Martins , Roque Valeska Rodrigues , Roquete Ana Paula Jardim , Mossmann Anelise , Viana Lorena Aparecida Nunes , Henkes Angélica Karine , Luiz Carla Daniela Cordeiro , Galio Alexandre Ferreira , Zavareze Elessandra da Rosa
Published: August 2016

The production of biodegradable films has been studied to be a substitute of conventional plastics. The use of starch in biodegradable films are of great interest and starch modification improves an increase to the mechanical properties the film. The mechanical properties were evaluated by Dynamic Mechanical Analysis (DMA). The aim of this study is to determine the mechanical properties of biodegradable films produced from native and chemically modified potato starch. The starch was extracted and subjected to chemical modification by oxidation in different concentrations of active chlorine. The biodegradable films were prepared with starch and glycerol as plasticizer, and were observed with an optical microscope to evaluate the morphology and their relationship with the strength. The tensile tests were performed at 80oC to evaluate the mechanical properties by means of stress-strain curves. The morphology of biodegradable potato starch films shows that the starch granules were partially gelatinized during the film formation. As the elastic modulus is a property which determines the stiffness of the material, by means of he DMA analysis it can be seen that oxidation results in beneficial changes in the mechanical properties of the films, because the modulus increased from 346.70 MPa for the native starch to 651.75 MPa to oxidized starch with 1.5% of active chlorine, respectively.
Morphological Analysis of Membranes of PES/Commercial Clay
Authors: de Carvalho Thamyres Cardoso , Nóbrega Medeiros Vanessa , Araújo Edcleide Maria , Leite Amanda Melissa Damião
Published: August 2016

The separation membrane processes are still fresh, but have had a lot of attention because they present attractive, such as low energy consumption, greater operating flexibility and better quality in the final product. Obtaining membranes incorporating clay is attracting interest because it improves the membrane filtration properties. In this study, pure polymer membranes were produced from poly (ether sulfone) and clays Cloisite Na and 20A, the levels of 1, 3 and 5% from the phase inversion technique using the dimethylformamide solvent. XRD results indicated the presence of a peak at both at about 15.8° compositions indicating that the systems are possibly intercalated and/or microcomposites structures. SEM results showed that the membranes with clay showed different behavior in relation to pure PES membranes. They apparently exhibited a surface without pores with exception of membrane with 5 wt.% Na Cloisite, which showed pores on its surface.
Rheological Behavior of Paraffin-Alumina Emulsions and their Microstructural Effects
Authors: Sanches Mariana Ferreira , Vitorino Nuno Miguel Dias , Abrantes João Carlos de Castro , Frade Jorge Ribeiro , Neto João B. Rodrigues , Hotza Dachamir
Published: August 2016

Cellular ceramics were prepared by emulsification of aqueous alumina suspensions with liquid paraffin, using collagen as a shape stabilizer and a dispersant to adjust viscosity. Rheological measurements of emulsions and microstructural analysis of the sintered samples were performed. The results show that the concentration of collagen, dispersant content and stirring rate affect directly the emulsion viscosity which causes changes in porosity and average cell size.
Evaluation of Antibacterial Activity of Chitosan Membranes Associated to Unripe Banana Peel
Authors: Battaglini Franco Patrícia , de Almeida Leiliane Aparecida , Marques Rodrigo Fernando Costa , Brucha Gunther , Campos Maria Gabriela Nogueira
Published: August 2016

The treatment of skin wounds is a worldwide problem due to possible complications of healing process, such as infections, sepsis and even death. Current treatment strategies involves the use of dressings, bandages and topical application of antibiotic to the wound. An ideal dressing should protect against bacterial contamination, while covering the wound. The aim of this study was to investigate the antibacterial activity of chitosan membranes associated to banana peel for potential wound dressing application, since both materials have previously demonstrated antimicrobial properties. The active principles of banana peel were extracted by two methods: decoction and drying. Membranes were prepared by chitosan association with the extracts of first and third days of decoction and with different concentrations of dried extract, by the casting/solvent evaporation techniques. All obtained membranes were uniform, flexible and easily unmolded. Antibacterial activity studies were performed by the Surface Plating technique. Inhibition of bacterial growth was evaluated against two bacteria Escherichia coli and Staphylococcus aureus, usually present in skin wounds. All membranes were able to inhibit S. aureus e E. coli growth by contacting. In addition to contacting inhibition of E. coli growth, an inhibition halo of 0.5 cm diameter was also observed around the chitosan-unripe banana peel membrane prepared with the extract of first day of decoction.
Antibacterial Activity of a Chitosan Derivative Obtained in the Absence of a Solvent
Authors: Osório Luizângela Reis , Lima Idglan Sá , Barreto Humberto Medeiros , Osajima Josy Anteveli , Silva Filho Edson Cavalcanti
Published: August 2016

A novel chitosan derivative was prepared through direct reaction of pure chitosan with acetylacetone in the absence of a solvent, and it was characterized by elemental analysis, Fourier transform infrared spectrometry (FTIR), and 13C Nuclear Magnetic Ressonance (NMR) spectroscopy. Moreover, the antibacterial properties of the new biomaterial were tested by the direct contact method against multi-drug resistant strains of Staphylococcus aureus and Escherichia coli. The results from the characterization were consistent with the modification of the chemical structure made. The new derivative showed a better antibacterial activity than raw chitosan against E. coli strains, indicating that incorporation of imine link (Schiff base) enhanced its antibacterial activity against Gram-negative bacterium. On the contrary, this chemical change did not decrease its antibacterial activity against Gram-positive bacterium.
Evaluation of the Potential of Mesocarp Babassu Powder as a Technological Excipient to Pharmaceutical Industry - Part I
Authors: Barros Ilka de Carvalho , Freire Lécia Maria da Silva , Soares Sobrinho José Lamartine , Silva Filho Edson Cavalcanti , Nunes Lívio César Cunha
Published: August 2016

The excipients were considered mere substances capable of facilitating and protecting the drug administration. Currently, are essential constituents, which guarantee the performance of the product and optimize the therapeutic effect. In search of a new material, the present work, wthrough a rheological study, thermal (TG / DTG) and X-ray diffraction (DRX) studies, evaluated the use of babassu mesocarp powder (MB) as technological excipient. The results of the rheological characteristics of MB as well as their granules against the microcrystalline cellulose and starch were satisfactory for use as an excipient. The thermal characteristics revealed similarity between MB, starch and cellulose, however, the greatest similarity was with the starch. The DRX data revealed that the MB has an amorphous structure similar to the structure of starch, corroborated the data obtained by TG / DTA. Therefore we conclude that the MB has favourable properties for use as an excipient in the pharmaceutical industry.
Hydroxyapatites Obtained from Different Routes and their Antimicrobial Properties
Authors: Feitosa Giselle Torres , Santos Marcus Vinicius Beserra , Barreto Humberto Medeiros , Nunes Lívio César Cunha , Osajima Josy Anteveli , Silva Filho Edson Cavalcanti
Published: August 2016

Among applications of ceramics in technological context, hydroxyapatite (HAp) stands out in the scientific community due to chemical biocompatibility and molecular similarity with the structures of bone and dental tissues. Such features are in addition to its antimicrobial properties. This work aimed firstly to synthesize hydroxyapatite by two different routes: hydrothermal (HD HAp) and co-precipitation (CP HAp), and secondly to verify the antimicrobial properties of these materials through direct contact tests against Staphylococcus aureus (SA10) and Escherichia coli (EC7) bacteria. These materials were characterized by XRD, Raman, and TEM. Antimicrobial tests showed inhibitory efficacy of 97.0% and 9.5% of CP HAp for SA10 and EC7, respectively. The HD HAp showed inhibitory effect of 95.0% and 0.0% for SA10 and EC7, respectively. The inhibitory effect of the tested materials against Staphylococcus aureus may be related to the HAp hydrophilicity.
Hydroxyapatite Nanoparticles: Synthesis by Sonochemical Method and Assessment of Processing Parameters via Experimental Design
Authors: Fernandes Cóta Lívia , Licona Karla Patricia Macedo , Lunz Juliana do Nascimento , Ribeiro Alexandre Antunes , Alonso Lizette Morejón , de Oliveira Marize Varella , Pereira Luiz Carlos
Published: August 2016

Hydroxyapatite (HAp) has been synthesized by different techniques, and sonochemical methods have shown to be useful in the HAp nanopartcicles production for biomedical applications such as bone graft substitute. In addition, experimental design is an appropriate tool for planning and evaluating a study to meet specified objectives. Then, this work aimed to synthesize HAp nanosized powders by a sonochemical method and assess the processing parameters via experimental design, in order to obtain dense samples. HAp nanopowders were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope/Field Emission Gun (SEM/FEG). For densification analysis, HAp samples were processed with different parameters, such as: compaction pressure (200 or 400 MPa), sintering temperature (900 or 1100°C), sintering heating rate (2 or 20 °C/min), and sintering time (2 or 4 hours). The samples were analyzed by SEM/FEG, whereas the linear shrinkage and density were considered the response variables for the experimental design. The results indicated that the sonochemical method successfully produced HAp nanoparticles with sphere-like morphology. Further, the experimental design showed that sintering temperature was the variable that most influenced the densification of samples.
Effect of Some Heat Treatments on Anelastic Properties of Ti-15Zr-xMo Alloys
Authors: Correa Diego Rafael Nespeque , Lourenço Mariana Luna , Kuroda Pedro Akira Bazaglia , Buzalaf Marília Afonso Rabelo , Grandini Carlos Roberto
Published: August 2016

Ti and Ti-based alloys have favorable properties for biomedical applications, such as high specific strength, low Young’s modulus, excellent corrosion and wear resistance, and good biocompatibility. The addition of alloying elements and heat treatments can result in a good combination of properties. Mo and Zr are β-stabilizer elements that decrease the Young’s modulus and increase the mechanical strength and corrosion resistance. Oxygen is an interstitial element that can improve mechanical strength and prevent ω phase formation. In this study, we analyzed the influence of substitutional and interstitial elements, and some heat treatments in the crystalline structure, microstructure and selected mechanical properties (Vickers microhardness, Young’s modulus and internal friction) of Ti-15Zr-xMo (5, 10, 15 and 20 wt%) alloys. The alloys exhibited dependence on the alloying elements and heat treatments, which resulted in different structural and microstructural changes. The mechanical properties were dependent on phase transformations induced by the compositions and heat treatments.
Preparation and Characterization of Ti-10Mo-xZr Alloys for Biomedical Applications
Authors: de Araújo Raul Oliveira , Buzalaf Marília Afonso Rabelo , Grandini Carlos Roberto
Published: August 2016

Titanium alloys are constantly being studied for possible applications as biomaterials. However, studies suggest that aluminum and vanadium, when used in the human body over long period of time, are associated with adverse reactions and allergies. So there is a need to develop alloys that are both free of these elements and have mechanical properties that are good as or better than the Ti-6Al-4V alloy. In this paper, alloys were prepared from the Ti-10Mo-xZr system (x = 5, 10, 15, 20 wt%). These were characterized by their chemical composition via energy dispersive spectroscopy (EDS), density, x-ray diffraction, optical microscopy, and microhardness. The results showed that the alloys have the desired stoichiometry and a good homogeneity structure. Microstructure analyses indicated the predominance of the β phase with a body-centered cubic crystal structure and that the addition of substitutional elements caused the solid solution to harden.
Effect of Hot Swaging on Microstructure and Properties of Aged Ti-10Mo-20Nb Alloy
Authors: Gabriel Sinara Borborema , Dille Jean , Nunes Carlos Angelo , Santos Jr. Emanuel , Baldan Renato , Mei Paulo , Castro Rezende Monica , Araujo Leonardo Sales , de Almeida Luiz Henrique
Published: August 2016

Mechanical properties of metastable β-Ti alloys are highly dependent on the final microstructure, which is controlled by the thermomechanical processing. These alloys are used for biomedical applications and require a high mechanical strength as well as a low Young’s modulus to avoid stress shielding. Previous work on the development of cold swaged Ti-10Mo-20Nb alloy showed that the best compromise strength and Young ́s modulus was obtained when the forming is followed by an aging heat treatment at 500 oC. In this work, Ti-10Mo-20Nb alloy was hot swaged and aged at 500 oC for 10 min, 4h and 24h. The microstructure was analyzed by X-ray diffraction, optical microscopy and transmission electron microscopy. Mechanical characterization was based on Vickers microhardness tests and Young’s modulus measurements. Aging at 500 oC for 10 min after hot swaging resulted in a nearly 100% β phase microstructure while aging at 500°C for 4h or 24h led to a bimodal microstructure consisting on α precipitates dispersed in the β matrix. The higher hardness to Young’s modulus ratio was obtained for the sample aged at 500 °C for 4h. This value was higher than those obtained for the Ti-6Al-4V alloy and commercially pure Ti.
Pd-Based Electrocatalysts Prepared by Borohydride Reduction Method for Methanol and Ethanol Electro-Oxidation in Alkaline Medium
Authors: Brandalise Michele , Tusi Marcelo Marques , Spinacé Estevam Vitorio , Oliveira Neto Almir
Published: August 2016

Pd/C, Au/C, AuBi/C, PdAu/C, PdAuBi/C electrocatalysts (with different atomic ratios and 20 wt% of metal loading) were prepared by borohydride reduction method using a water/2-propanol mixture as solvent, Pd (NO3)2.2H2O, HAuCl4.3H2O and Bi (NO3)3.5H2O as metal sources, carbon black Vulcan XC72 as support and NaBH4 as reducing agent. The activities of the prepared electrocatalysts for methanol and ethanol electro-oxidation in alkaline medium were investigated by chronoamperometry using the thin porous coating technique. Chronoamperometry experiments showed that PdAu/C (Pd:Au atomic ratio of 50:50) has superior activity and stability for methanol and ethanol electro-oxidation compared with other catalysts.
Real presence. Outline of an ecumenical review
Authors: Klän Werner
Published: August 2016

The issue of an adequate description, a conceptual formulation and a theological interpretationof the gift of the Lord’s Supper, has been a concern of Christianity since ancient times. Thecircumspect observation in the Charta Oecumenica (2001) reads: ‘Fundamental differences infaith are still barriers to visible unity’. In the light of those difficulties, attempts have beenmade in recent years to work on a ‘Joint Declaration on the Lord’s Supper’. All churches anddenominations face the challenge to bring that which they learn of Jesus Christ’s sacramentalpresence from the New Testament. Some rapprochements have been achieved in the lastdecades. Some of those results are discussed in this essay.
Tropologiese Hoogliedmetafore en vroulike mistieke piëtisme in Suid-Afrikaanse pioniergemeenskappe, 1760–1860
Authors: Raath Andries W.G.
Published: August 2016

The ego-focus of pioneer women on the South African frontier, 1760–1860, reflects distinct traits of mystical spirituality. The pioneer spirituality of women on the borders increasinglycame to expression in ego-texts with experiential inclinations. The leaning towards Jesuscentredmystical spirituality developed parallel to pietistic tendencies in Holland and Germany,and allegorical and tropological applications of the bridal metaphors in the Song of Songsformed a distinct element of female pietism on the frontier. Women believers in the interiorfavoured tropological applications of bridal metaphors in the Song of Songs. The popularity ofsuch tropological applications can firstly be attributed to the physical conditions under whichpioneer women found themselves. Secondly, the availability of German pietistic workscontributed towards the religious culture of mystical and individualistic readings of bridalmetaphors in the Song of Songs. Tropological readings of the Song of Songs’ bridal metaphorsare traced to the theology of Bernard of Clairvaux particularly and other pre-reformationalmystical sources.
How to expect God’s reign to come: From Jesus’ through the ecclesial to the cosmic body
Authors: Urbaniak Jakub , Otu Elijah
Published: August 2016

This study seeks to articulate the universality of the eschatological expectation, in its specifically Christian form, by interpreting it from the perspective of a radical embodiment. This can be understood in a twofold manner. Firstly, the mysterious reality of the eschatological reign of God is rooted in – and thus can be more adequately grasped through the lens of – Jesus’ own body seen as distinct yet not separate from his risen body and, mutatis mutandis, from his extended body, both ecclesial and cosmic. Secondly, for the eschatological expectation to be lived out in an incarnational way, it must be ‘enfleshed’ in actions aimed at social and ecological liberation.The article consists of four sections. Firstly, we explain in what sense body – and more specifically Jesus’ body – is used in our analysis as a hermeneutic key to notions such as ‘risen body’, ‘spiritual body’, ‘extended body’, ‘social body’, ‘ecclesial body’, ‘cosmic body’, basar/kol basar (‘flesh’/‘all flesh’), and ‘life’. Then, the universality of the eschatological expectation is being articulated on two levels, namely, (1) with regard to the social, and in particular the ecclesial, body, and (2) with regard to the cosmic body, with ecological implications inherent in such perspective. Finally, we close the loop by briefly revisiting the notion of Jesus’ body.
Re-enchanted by beauty. On aesthetics and mysticism
Authors: De Villiers Pieter G.R.
Published: August 2016

The article investigates the potential of mysticism to revitalise theology. It firstly traces howaesthetics was understood in theology and provides reasons for this view. It then investigateshow the predominant epistemological approach in theology privileged conceptual knowledgeand relativised aesthetics as being subjective and therefore unreliable. It gives special attentionto this epistemology by spelling out how the intellectualisation of contemporary theologyintensified the process of obfuscating and sidelining aesthetics. In a third part, the article spellsout the consequences of this position by analysing how theology is becoming a disenchantedenterprise. The article then investigates how aesthetics often is taking over the role of theologyand its formative role in social discourse. It focuses on the epistemological nature of this turntowards aesthetics, arguing that aesthetics with its profound notion of beauty (with goodnessand joy as its corollaries), is increasingly reappraised as a legitimate, but different kind andsource of knowledge. The article then argues how aesthetics can reinvigorate theology as asource of knowledge together with conceptual knowledge. It ends by investigating howtheology can be re-enchanted by learning from the prominent role and invigorating forms ofaesthetics in mysticism.
Aesthetics, mysticism and the art of living
Authors: De Villiers Pieter G.R.
Published: August 2016

This article analyses aesthetics and mysticism in the writings of Albert Geyser, the prominent South African theologian who is mostly known for his brave, uncompromising struggle against the apartheid system. In the first part of the article, brief introductory comments are made about Geyser’s theological and political role in South Africa in the light of his Protestan tcontext and his opposition to apartheid. It is then investigated how his reputation as a Biblical scholar and his protracted, much publicised stance against apartheid obfuscate his remarkable interest in aesthetics and mysticism and explains why his other theological interests and especially his interest in mysticism have not yet been researched. In the second part of the paper Geyser’s mystical interests are investigated by analysing his comments on church architecture, worship, music, liturgy and his pioneering translation of Thomas á Kempis’ Imitatio Christi.
Expanding the disaster risk management framework: Measuring the constructed level of national identity as a factor of political risk
Authors: Prinsloo Barend , Van der Waldt Gerrit
Published: August 2016

Political risk is identified as a dominant risk category of disaster risk management (DRM) which could negatively affect the success of those measures implemented to reduce disaster risk. Key to political risk is the construct of national identity which, if poorly constructed, could greatly contribute to political risk. This article proposed a tool to measure the construct of national identity and to provide recommendations to strengthen the construct in order to mitigate the exacerbating influence it may have on political risk and ultimately on DRM. The design of the measurement tool consisted of a mixed methodological approach employing both quantitative and qualitative data. The data collection instruments included a literature review (which is shortly provided in the previous sections) and an empirical study that utilised data obtained through structured questionnaires. Although the results of the proposed measuring instrument did not include a representative sample of all the cultures in SouthAfrica, the results alluded to different levels for the construction of national identity among black and white respondents, possibly because of different ideological expectations among these groups. The results of the study should be considered as a validation of the measuring tool and not necessarily of the construct of national identity in South Africa. The measuring tool is thus promising for future studies to reduce political risk and ultimately disaster risk.
Insurance mechanisms for tropical cyclones and droughts in Pacific Small Island Developing States
Authors: Baarsch Florent , Kelman Ilan
Published: August 2016

One group of locations significantly affected by climate-related losses and damage is the Small Island Developing States (SIDS). One mechanism aiming to reduce such adverse impacts is insurance, with a wide variety of products and models available. Insurance for climate-related hazards affecting Pacific SIDS has not been investigated in detail. This article contributes to filling this gap by exploring how insurance mechanisms might be implemented in the Pacific SIDS for tropical cyclones and droughts. The study examines opportunities and constraints or limitations of some existing insurance mechanisms and programmes as applied to the Pacific SIDS. Eight insurance mechanisms are compared and discussed regarding the premium cost compared to the gross domestic product per capita, the amount of payout compared to the damage cost, the reserve and reinsurance, and the disaster risk reduction incentives. As such, this article offers a decision-making tool on insurance development for the Pacific SIDS. Ultimately, implementing disaster insurance for the Pacific SIDS depends on political will and external technical and financial assistance.
Collaborating to compete: The role of collective creativity in a South African clothing design small business
Authors: Tselepis Thea J. , Mastamet-Mason Anne , Antonites Alex J.
Published: August 2016

Background: The number of apparel manufacturers in the South African clothing and textile industry is diminishing due to competition with importing apparel manufacturers. Nevertheless, South African small and micro-businesses still manufacture clothing products to meet the needs of the local markets.

Aim: This study set out to explore and describe the role of collective creativity in the design process of a South African clothing small business that provides innovative clothing to local niche markets.

Setting: The small and micro-businesses are typically owned by designers who can be viewed as artisan entrepreneurs. However, the competition for the local market is very competitive, and innovative designs and design processes can promote the competitiveness of the clothing small and micro-businesses.

Method: A case study research design was implemented in the study, which included qualitative research methods. Semi-structured interviews, participant observation and analysis of the products against an innovation design framework were done.

Results: The findings suggest that a collaborative design process supports the collective creativity of the particular owner-designers. Collective creativity enables innovative clothing products that result from the design process and it also reduced the perceived risk that the owner-designers experienced with regard to launching a ready-to-wear range.

Conclusion: It is argued that collective creativity contributes to sustaining innovative design and enhances abductive reasoning for problem solving. Abductive reasoning, which is typically associated with design thinking, could be important for entrepreneurial thinking and recommendations in this regard are made.
Rewards: A predictor of well-being and service quality of school principals in the North-West province
Authors: Nthebe Kamohelo , Barkhuizen Nicolene , Schutte Nico
Published: August 2016

Orientation: School principals have an important role to play in the quality of service delivery in schools. Evidence suggests that school principals are generally poorly compensated, which has an adverse impact on their well-being and subsequent service quality orientation.Research purpose: This study investigated whether rewards are a predictor of well-being and service orientation of school principals in the North-West province.Motivation for the study: Effective school principals are fundamental to the success of any school, which necessitates the establishment of an effective reward and remuneration system.Research design, approach and method: Quantitative research was carried out among school principals (N = 155) in four districts of the North-West province. The Total Rewards Scale, Maslach’s Burnout Inventory – General Survey, the Utrecht Work Engagement Scale and the SERVQUAL measure were administered among the principals.Main findings: The results showed that rewards are a significant predictor of the well-being and service quality of school principals. The results further showed that burnout significantly reduces the service quality of school principals. No significant relationships were found between work engagement and the service quality of school principals.Practical/managerial implications: An effective total rewards system enhances the well-being of school principals and, subsequently, their willingness and commitment to delivering quality services.Contribution: The results of this study point out some key elements that need to be considered by the Department of Education to enable quality service delivery in South African schools.
Cardiovascular imaging: Quiz case
Authors: Misser Shalendra
Published: August 2016

No abstract available
Afrikaans as a complex network: The word co-occurrence network in André P. Brink’s Donkermaan in Afrikaans, Dutch and English
Authors: Senekal Burgert A. , Geldenhuys Cornelia
Published: August 2016

Language has already been approached as a system since De Saussure, and recently the theory of complex systems has been applied within Linguistics as well. Complex systems, however, can also be modelled as complex networks, and a variety of studies investigating the network structure of language have already been undertaken worldwide. The current study follows in the footsteps of overseas studies and investigates the network structure of Afrikaans by analysing a word co-occurrence network compiled from André P. Brink’s novel Donkermaan. Link distribution patterns and the small-world phenomenon are investigated and then compared to the English and Dutch translations of this novel. The current study represents the first network study of Afrikaans. Firstly, the random network model of Erdös and Rényi and the scale-free network model by Barabási and Albert are used to indicate that the link distribution patterns in a word co-occurrence network of Afrikaans are better described according to the network model of Barabási and Albert than by that of Erdös and Rényi. Furthermore, the method proposed by Humphreys and Gurney to define smallworldedness (S) was used to quantify this phenomenon for the Afrikaans, as well as English and Dutch versions of the text. With 522 ≤ S ≤ 797, it is indicated that Afrikaans, English and Dutch are all clearly small-world networks. Suggestions are also made for further research.
A Simple Method for Computing Singular or Nearly Singular Integrals on Closed Surfaces
Authors: Beale J. Thomas , Ying Wenjun , Wilson Jason R.
Published: August 2016

We present a simple, accurate method for computing singular or nearly singular integrals on a smooth, closed surface, such as layer potentials for harmonic functions evaluated at points on or near the surface. The integral is computed with a regularized kernel and corrections are added for regularization and discretization, which are found from analysis near the singular point. The surface integrals are computed from a new quadrature rule using surface points which project onto grid points in coordinate planes. The method does not require coordinate charts on the surface or special treatment of the singularity other than the corrections. The accuracy is about O(h3), where h is the spacing in the background grid, uniformly with respect to the point of evaluation, on or near the surface. Improved accuracy is obtained for points on the surface. The treecode of Duan and Krasny for Ewald summation is used to perform sums. Numerical examples are presented with a variety of surfaces.
A Contact Line Dynamic Model for a Conducting Water Drop on an Electrowetting Device
Authors: He Dongdong , Huang Huaxiong
Published: August 2016

The static shape of drop under electrowetting actuation is well studied and recent electrowetting theory and experiments confirm that the local contact angle (microscopic angle) is unaffected while the apparent contact angle (macroscopic angle) is characterized by the Lippmann-Young equation. On the other hand, the evolution of the drop motion under electrowetting actuation has received less attention. In this paper, we investigate the motion of a conducting water drop on an electrowetting device (EWD) using the level set method. We derive a contact line two-phase flow model under electrowetting actuation using energy dissipation by generalizing an existing contact line model without the electric field. Our model is consistent with the static electrowetting theory as the dynamic contact angle satisfies the static Young's equation under equilibrium conditions. Our steady state results show that the apparent contact angle predicted by our model satisfies the Lippmann-Young's relation. Our numerical results based on the drop maximum deformation agree with experimental observations and static electrowetting theory. Finally, we show that for drop motion our results are not as good due to the difficulty of computing singular electric field accurately. Nonetheless, they provide useful insights and ameaningful first step towards the understanding of the drop dynamics under electrowetting actuation.