bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic Study on Martensite Formation in Steels 1045 and 4340 under Variable Cooling Rates
Authors: Bubnoff Dimitry V. , Carvalho Mariana M.O. , de Castro José Adilson , Lourenço Thiago R.M.
Published: August 2016

The experiments were carried with two steels with different chemical compositions, aiming at understanding and comparison with the available literature. The microstructures of steels 1045 and 4340 were characterized and quantified using scanning electron microscopy (SEM) and optic microscopy (OM) with quantitative methods. Based on the experimental results, the amount of martensite, the hardness and the microhardness were determined, as a function of the distance from the quenching end, under different cooling conditions. For predicting the evolution of martensitic fraction along the sample, Koistinen-Marburger’s (K-M) model was adopted. It was found that the parameters recommended in the literature for the traditional K-M model do not represent accurately the results obtained for the steel samples under investigation. According to indications found in recent literature, parameter corrections were proposed, leading to a modified K-M model which better represents the transformations observed in the different examined steels.
Hysteresis Modeling of NdFeB Magnets with High Nd
Authors: de Campos Marcos Flavio , Sampaio da Silva Fernanda A. , de Castro José Adilson
Published: August 2016

The Stoner-Wohlfarth hysteresis model can describe very well the hysteresis curves since the assumptions of the model are compatible with the studied samples. These conditions are (i) single domain particle size and (ii) inexistence of interactions between the particles. These conditions are obtained in Nd2Fe14B magnets with nanocrystalline grain size below 200 nm and with high Nd, which promotes a paramagnetic phase at the grain boundaries. In the present study, both isotropic and anisotropic NdFeB magnets are modeled.
Loss Separation Model: A Tool for Improvement of Soft Magnetic Materials
Authors: de Campos Marcos Flavio
Published: August 2016

Loss separation has fundamental importance for optimizing the magnetic material for a given frequency of operation. The loss separation model assumes the existence of two main terms: one due to the hysteresis at the quasi-static situation with frequency less than 0.01 Hz and another dynamic, due to high frequency eddy currents. In this study, it is discussed the physical reasoning behind the loss separation model. Magnetic Barkhausen Noise can be a valuable tool for better understanding the physics of loss separation.
Effect of Cooling Rate on the Corrosion Behavior of As-Cast SAF 2205 Duplex Stainless Steel after Solution Annealing Treatment
Authors: Cronemberger Maria Eurenice Rocha , Nakamatsu Sandra , Mariano Neide Aparecida , della Rovere Carlos Alberto , Kuri Sebastião Elias
Published: August 2016

The formation of intermetallic phases alters the properties of duplex stainless steel and is therefore a crucial factor in its performance. For example, the formation of sigma phase in duplex steel increases its brittleness and decreases its corrosion resistance because this phase consumes chromium and molybdenum in solid solution, thus leading to the depletion of these elements in the matrix. This study investigated the corrosion resistance of as-cast SAF 2205 duplex stainless steel after solution annealing treatment at 1100 °C for 240 minutes, under varying cooling rates. The objective was to evaluate the correlation between cooling condition, microstructural changes and corrosion resistance based on cyclic potentiodynamic polarization tests and double loop electrochemical potentiokinetic reactivation (DL-EPR) measurements. The results revealed a significant reduction in the corrosion resistance of a slowly cooled sample, which presented an increase in the degree of Cr (Qr / Qa) depletion resulting from the formation of sigma phase.
Fracture Stress Analysis in Ceramic Composites of Alumina Matrix with Zirconia 3Y-TZP Nanograins for Mechanical Shielding of Satellites
Authors: Fernandes da Silva Eron , Nono Daniel Alessander , Mineiro Sergio Luiz , Neto Francisco Piorino , Nono Maria do Carmo de Andrade
Published: August 2016

This paper presents the analysis results of fracture stress values for ceramic composites of alumina matrix mixed with nanoparticulate zirconia (3Y-TZP) ((tetragonal zirconia polycrystalline doped with 3 mol% yttria), which will be used in parts of the Brazilian satellites to act as mechanical shield for micrometeoroid and space debris impacts. The ceramic composites were obtained by mixing dispersed suspensions of alumina powders and 18.5 wt % of nanoparticulate zirconia, compacted with isostatic pressure and sintered at 1550 °C. After sintering, the ceramic composite was analyzed by SEM, X-ray diffraction and subjected to 4 points mechanical bending test. The microstructure analyses were performed and rupture stress values with Weibull distribution. The results were compared to previous works obtained after mechanical mixture of same powders. The results analyses showed that the greater homogeneity distribution of zirconia nanograins on alumina matrix contributes to increased fracture stress values.
Study of the Efficiency of Ag-SiO2 Nanoparticles as Additives in Anticorrosion Coatings
Authors: Pletsch Rômulo de O. , Alves Kleber G.B. , Vieira Magda R.S. , de Melo Celso P. , Bouchonneau Nadège S.
Published: August 2016

In this work, Ag-SiO2 nanoparticles were used as additives in an epoxy paint to evaluate their efficiency to protect SAE 1020 carbon steel from corrosion. Ag-SiO2 particles were characterized using X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Samples of ABNT 1020 steel were coated with an industrial epoxy based paint added with Ag-SiO2 nanoparticles. Electrochemical tests of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were conducted to evaluate the anticorrosive behavior of the investigated coatings when exposed to saline solution. DLS data show that Ag-SiO2 particles have average diameters of around 223.4 nm. TEM images highlight the presence of Ag-SiO2 particles agglomeration. EIS and OCP measurements show that addition of 0.5% w/w Ag-SiO2 to the epoxy paint could improve the efficiency of the anticorrosive coating, when compared to the epoxy paint without any corrosion inhibitor. Results also show the importance of developing efficient dispersion techniques to avoid the agglomeration of the particles that may increase the porosity of the coating and thus affect its corrosion protection efficiency.
Synthesis and Sintering of LaCo1-XFexO3 Ceramics: Microstructure Analysis
Authors: Paula Gustavo R. , Ribeiro Daniel Véras , Morelli Márcio Raymundo
Published: August 2016

This work intends to show the effect of the iron ion doping in LaCoO3 perovskite, both in powders and in sintered samples obtained from combustion reaction route. The phase formation and particle morphology and particle size distribution of the powders were analysed by XRD, SEM and sedimentation techniques, respectively. Relative density, microstructure (secondary phases and grain size) and pore size distribution of LaCo1-xFexO3 sintered ceramics have been investigated by SEM/EDS and Hg porosimetry analysis. Although LaCo1-xFexO3 powders obtained from combustion reaction exhibited smaller grain sizes when sintered at high temperatures, they showed higher volume fraction of secondary phases. The presence of these crystalline phases in addition to the desired perovskite affected the microstructure acting as grain growth inhibitors by grain boundary pinning. It is believed by observing three grain junction pores that LaFeO3 phase has a smaller dihedral angle than LaCoO3. This fact would explain why LaFeO3 presented a smaller driving force for sintering with higher tendency of pore and inclusion coarsening at higher temperatures (1400°C).
Effect of Thermal Aging at Low Temperature on the Mechanical Properties and Corrosion Resistance of LDX 2404 Duplex Stainless Steel
Authors: Silva Rodrigo , della Rovere Carlos Alberto , Kuri Sebastião Elias
Published: August 2016

It is well known that when duplex stainless steels (DSS) are subjected to temperatures ranging from 300 to 1000 °C they may undergo precipitation of several phases, which can seriously impair their mechanical properties and corrosion resistance. The present work studied the effect of thermal aging (up to 2000 h) at 475 °C on the corrosion and mechanical properties of the newly developed 2404 DSS. The evaluation was based on potentiodynamic polarization in 3.5% NaCl solution and on Charpy tests. The pitting corrosion resistance was found to decrease significantly with aging time at 475 °C. In addition, Charpy tests revealed that after 100 h of thermal aging the material becomes brittle due to the spinodal decomposition of ferrite.
Analysis of the Metallurgical Bonding between Inconel and NiCrAlY Coatings by HVOF and with CO2 Laser Beam
Authors: Costa Oliveira Ana Claudia , Donato G. , Magnabosco R. , Teleginski Viviane , Chagas Daniele Cristina , de Vasconcelos Getúlio , Camargo F.
Published: August 2016

Coatings are applied on turbine blades’ surfaces to provide protection not only against high temperature but also against aggressive environment. Ceramic coatings are employed to avoid metallic substrate overheating, while at the same time increasing turbine work temperature and performance. A bond coat (BC) base of particulate material based on Ni-Al powders is necessary to assure oxidation protection, a good adhesion and gradual decrease in thermal expansion coefficient between the blades’ metallic substrate and the ceramic top coating. One of the most important parameters of such coatings is the adhesion strength. In this work, a NiCrAlY bond coat was deposited on Inconel 625 substrate employing High-Velocity Oxygen-Fuel (HVOF) thermal spraying technology and CO2 laser beam irradiation to enhance coating–substrate adherence and metallurgical bonding. Microstructural features were examined by optical and scanning electron microscopy (SEM), X-ray diffraction and microhardness analysis. The results indicate that the laser treatment provided an efficient metallurgical bond between the (BC) and Inconel 625 substrate.
Thermal Characterization of Neodymium-Barium-Copper Ceramic (NBCo Ceramic) Synthesized from Barium Carbonate
Authors: Fernandes José Passos , Tibola A. , Lorensetti M. , Duarte G.W. , Rocha M.R. , Montedo O.K. , Riella Humberto Gracher , Fiori Márcio Antônio
Published: August 2016

This work presents a study about thermal properties of a ceramic material based on NdBaCu system sintered with barium carbonate. These specialized ceramics are manufactured under special conditions and due to its unique electrical and thermal properties are frequently used by the electronic industry. Ceramics containing neodymium-barium-copper (NdBaCu) exhibit high conductivity at low temperatures. In this work, the ceramic samples were sintered with different percentage of barium carbonate, cupric and neodymium oxide and were characterized with Termogravimetric Analysis (TGA), Differential Scanning Calorimetric (DSC), Thermal Dilatometric Analysis (TDA) and X-Ray Diffraction Analysis (DRX). The results showed that the electrical conductivity of NdBaCu system is dependent on the calcination temperature. In turn, the complete calcination is dependent on the barium percentage and the thermal treatment conditions.
Synthesis and Characterization of CMC for Potential Application as Adsorbent in Water Treatment
Authors: Medeiros Borsagli Fernanda Guerra Lima , Mansur Alexandra A.P. , Mansur Herman Sander
Published: August 2016

Chitosan is a polymer from natural source with a wide range of applications, such as in the adsorption of heavy metals. However, it presents limitation in relation to pH, because it is insoluble in neutral and alkaline. Thus, a good alternative has been the use of derivatives of chitosan, as carboxymethyl chitosan (CMC). This chemical modification of chitosan may favor the adsorption process, because it broadens the pH range of solubility and the quantity of chemical groups available for the uptake of ions. This work was carried out the synthesis and characterization of carboxymethyl chitosan. The properties of derivatives synthesized were assessed through the study of solubility at different pHs and using the techniques of potentiometric titration, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis) spectroscopy and thermal analysis. The results have demonstrated the effective incorporation of carboxylic groups in the structure of chitosan, as well as the dependence of degree of substitution with the concentration of hydroxide during the synthesis. Hence, the chemical functionalization of chitosan for producing carboxymethyl chitosan offers the possibility of applying this new adsorbent for water treatment.
Study of the Interaction of Copper Nanoparticles with Titanium in Landfill Soils Layers
Authors: Mendes de Oliveira Elizabeth , de Castro José Adilson , Ferreira Ivaldo Leão
Published: August 2016

The nanotechnology has spread out for every field of the sciences and engineering with applications covering the variety of human and life activities. The TiO2 nanoparticles are of special interest due to the wide range of applications from cosmetics to paint and new applications have continuously been searched. However, the effect of these particles into the environment need detailed investigation since some deleterious effects on the ecosystems have been observed. Among the nanoparticles found in natural soils the copper plays important role due to their strong interactions with the other materials. In this paper, the influence of nanoparticles of copper (NPCu) in the behavior of NPTiO2 were investigated. A normalized experimental procedure on the soil column was carried out with soil impregnated by copper nanoparticles and compared with the natural soil. Stable solutions of water and NPTiO2 were prepared and used to carried out the column percolation experiments with the concentrations of NPTiO2 measured at the inlet and outlet of the solutions. The results indicated that the TiO2 nanoparticles can mediate transport of Cu in some soil environments. Suggested that decreases in Cu transport were mainly due to increased desorption.
Development of Polymer Membranes Modified with a Porogenic Agent
Authors: Medeiros Keila Machado , Lima Diego Farias , de Lima Carlos Antônio Pereira , Araújo Edcleide Maria , Lira Hélio Lucena , Nóbrega Medeiros Vanessa
Published: August 2016

Membrane is a barrier that separates two phases and limits wholly or partially carrying one or several chemical species present in the phases. In this study, membranes with a polyamide6 porogenic agent were obtained. The membranes were prepared as thin films by phase inversion method using the immersion technique, precipitation by varying the percentage of porogenic agent introduced and the time of exposure of the membranes during the process of immersion-precipitation. The membranes obtained were characterized by scanning electron microscopy (SEM). From the SEM photomicrographs, a large morphological change was observed over the entire surface layer of the membranes, significantly affecting the size and number of pores. Furthermore, porogenic agent promoted the formation of pores and the increase in planar microporous membranes obtained.
Nanostructured and Electroactive Hybrid Films Containing Microcrystalline Cellulose Modified with the Phosphate Group: Synthesis and Characterization
Authors: Teixeira Paulo Ronaldo Sousa , Marreiro Ana Siqueira do Nascimento , Teixeira da Silva José Regilmar , Farias Emanuel Airton de Oliveira , Dionisio Natália de Araujo , Silva Filho Edson Cavalcanti , Eiras Carla
Published: August 2016

Nanostructured and electroactive hybrid films containing Microcrystalline Cellulose (MC) modified with the phosphate group (MCPO4) and polyaniline (PANI) were prepared using the Layer-by-Layer (LbL) self-assembly technique. In the preparation process of the films cellulose was dispersed in the solution of PANI and the film with PVS/PANI(MCPO4) structure was immobilized on ITO substrate. In order to investigate the influence of the phosphate group on the electrochemical behavior of the film, films were also prepared replacing the modified cellulose (MCPO4) by unmodified cellulose (MC), forming the PVS/PANI(MC) films. Subsequently, all films were characterized by cyclic voltammetry (CV), and the results showed the redox processes characteristic of PANI, but the presence of CMPO4 promotes an increase in the values of current density observed for the PVS/PANI(MCPO4) film when compared to the PVS/PANI(MC) film. This is probably due to a self-doping process of the polymer in the presence of phosphate groups.
Development and Evaluation of Capsule of Sodium Diclofenac and Paracetamol Using Mesocarp Babassu Powder as Excipient - Part II
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 capsules are pharmaceutical forms extremely versatile used to administer drugs orally, thus demonstrating the relevance of search for new excipients. Therefore, it was aimed to demonstrate the technological feasibility of babassu mesocarp powder (MB) as an excipient in development of diclofenac capsules 50mg and paracetamol 500 mg. Two lots of capsule were produced for each active ingredient separately using MB and microcrystalline cellulose (MC) as an excipient. The analytical results of quality control of all lots remained within the limits accepted by the Brazilian Pharmacopoeia. Although the values of dissolution time coming from lots of CM and MB, the statistical analysis revealed that lots manufactured with MB showed a profile of release superior to CM, demonstrating the potential of MB as an excipient once the lots produced with MB showed a disintegration and dissolution equivalent to those obtained with CM lots.
Development and Characterization of Chitosan Membranes as a System for Controlled Release of Piperine
Authors: Nascimento Imarally Vitor de Souza Ribeiro , Souza Mairly Karolyne da Silva , Barbosa Willams Teles , Fideles Thiago Bizerra , Marinho Thais Maria Alves , Fook Marcus Vinícius Lia
Published: August 2016

Among the variety of polymers used as drug carriers, chitosan has received attention in the fields of medicine and pharmacy by being a nontoxic, biocompatible and biodegradable copolymer. Piperine is a natural alkaloid, has various pharmacological activities such as anti-inflammatory, analgesic, antipyretic, hepatoprotective and antitumor when combined with chitosan has better bioavailability and more effectiveness. This work aims to prepare and characterize chitosan / piperine membranes obtained by the solvent casting method. The membranes were characterized by Spectroscopy Fourier Transform Infrared (FTIR), X-ray Diffraction (DRX) and Scanning Electron Microscopy (MEV). From the results obtained it can be concluded that the process described was effective in obtaining the system chitosan/piperine indicating its potential for studies of controlled release of drug.
Synthesis and Characterization of Fe3O4 Nanoparticles Stabilized by Polyvinylpyrrolidone/Polyethylene Glycol with Variable Mass Ratios
Authors: Sampaio da Silva Fernanda A. , de Campos Marcos Flavio , Rojas Edwin E.G.
Published: August 2016

Magnetic nanoparticles are devices able to optimize cancer treatments. In particular, magnetite nanoparticles are very effective in producing heat to cause lysis of tumor cells. However, in order that nanoparticles are internalized without causing damage to body they must be coated by biocompatible material. In this work, Fe3O4 nanoparticles were coated by a polymer blend: polyethylene glycol / polyvinylpyrrolidone. Some variations in mass ratio of polymer mixture were made. The effect of varying mass ratio in polymers was investigated. Samples were characterized by X-ray diffraction and Rietveld analysis. Moreover, hysteresis curves were analyzed. The results indicate good agreement between mass proportions used and physical and magnetic properties of nanocomposite.
Synthesis and Characterization of Ceramic Modified with Niobium for Biomedical Applications
Authors: Capanema Nadia Sueli Vieira , Mansur Alexandra A.P. , Mansur Herman Sander
Published: August 2016

The need for obtaining new materials to replace human body parts that were destroyed or damaged led scientists from different areas of research for developing new biomaterials. Thus, the aim of this work was the synthesis and characterization of niobium-modified apatite bioceramics. Calcium phosphates (CaP) were synthesized with niobium partially replacing calcium sites using aqueous precipitation route at room temperature. The bioceramics, with and without Nb incorporation, were characterized by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) as prepared and after heat treatments The results indicated that Nb was incorporated in the apatite structure promoting morphological and structural changes in the ceramic properties.
Osseointegration of Ti-30Ta Implants without Primary Stability: Effect of Tranexamic Acid
Authors: Rosifini Alves Rezende Maria Cristina , Capalbo Bruna Cabrera , Louzada Mario Jefferson Quirino , Rangel André Luiz Reis , Cintra Luciano Ângelo , de Oliveira João Augusto Guedes , Lisboa-Filho Paulo Noronha , Wada Cristiane Mayumi , Rosifini Alves Claro Ana Paula
Published: August 2016

A large clot formed between the inside of the bony wall of the extraction socket and the immediate implant surface may have premature breakdown . Tranexamic acid (TXA) is fibrinolysis inhibitor and an analog of the amino acid lysine. In this paper the influence of tranexamic acid on the osseointegration of Ti-30Ta implants without primary stability was investigated. Were fabricated 32 implants of CP Titanium Grade 4 and 32 implants of Ti-30Ta alloy with dimensions of 2.1 x 2.8mm Ø. Bone defects of 2.5x3.2 mm Ø were created in right tibia of 64 Wistar male-rats using a small round bur. They were divided (n=16) into: Group I (CP-Ti machined implant), Group II (CP-Ti machined implant/ tranexamic acid), Group III (Ti-30Ta implant) and Group IV (Ti-30Ta implant/ tranexamic acid). The surgical defects of the Group II and Group IV were bathed with 20 ml of the tranexamic acid solution. The animals were euthanized at 45 days postoperative. In the right tibia of half each group (8 animals/8 tibiae) the maximum torque value necessary for manual removal of each implant was measured in Newton centimeters (Ncm). The right tibia of other half each group was subjected to non-decalcified histology processing (Stevenel's blue/Alizarin red). Data were analyzed statistically (Kruskal-Wallis Analyses) and demonstrated significant differences (P<0.05) among groups. The values of group I were significantly lower than group III and IV, but without significant difference than group II both removal torque and peri-implant bone healing. The results suggest that: a) peri-implant bone formation occurred more rapidly around the Ti-30Ta implant; b) tranexamic acid favored the stabilization of blood clot and bone formation around Ti-30Ta implants and not influenced bone formation around Ti-CP implants.
Evaluation of Sample Preparation Parameters in the Compressive Strength of Cementitious Composites
Authors: de Figueiredo Maia Ana Luiza , Oliveira Sena Natalia , Oliveira Laura Luíza de Melo Sapori , Melo Pereira Gabriela , da Silva Mateus Justino , Resende Domingos Sávio , da Silva Neto João Trajano , de Aguilar Maria Teresa Paulino , Bezerra Augusto Cesar da Silva
Published: August 2016

This paper presents an experimental evaluation of how variations in proposed parameters interfere with compressive strength resistance of mortar and concrete specimens. The results were obtained through laboratory tests in which samples were tested under varying conditions. These conditions were as follows: speed of load application (0.25, 0.50, 0.75, and 1.00 MPa/s), environmental conditions (saturated, 2 h dried, and 24 h dried specimens), curing (dry and wet), and specimen ends preparation (sulphur, neoprene, rectification, and without regularization). Comparisons were made on the basis of the compression strength resistance results and the coefficient of variation in order to analyse the homogeneity and dispersion among variables. It was found that in the case of capping, the best results were obtained by the rectification of concrete specimens. In the case of loading speed, the best results were obtained at a speed of 1 MPa/s. Dry curing showed the best results, even though not resulting in the highest resistance. The results for specimen conditions were in accordance with the expectations, with lower dispersion for saturated specimens.
Mechanical and Microstructural Characterization of the Ti-25Ta-25Nb Alloy for Dental Applications
Authors: Seixas M.R. , Bortolini Jr. C. , Konatu R.T. , Pereira Jr. A. , Rosifini Alves Claro Ana Paula
Published: August 2016

Titanium and its alloys have been used in biomedical applications due to their excellent properties such as high corrosion resistance, biocompatibility and mechanical properties. In orthodontics, initially, it was common to use nickel-titanium alloys, however due to allergic reactions of patients, new titanium alloys containing elements such as niobium and tantalum are being studied. The Ti-25Ta-25Nb alloy is a β-titanium alloy and it has a low elastic modulus. In the present work, the ternary alloy was evaluated after cold work by swaging followed by solubilization treatment. Microstructure and mechanical properties were evaluated after each step of the process. Results were similar to find in the literature for this alloy obtained by other processing rote.
Evaluation of Setting Time, Ions Release, Sealing Ability and Adhesion of a Novel Experimental Endodontic Cement
Authors: dos Santos Alailson Domingos , Sostena Michela Melissa Duarte Seixas , Barbosa José Carlos , dos Santos Paulo Henrique , Gandolfi Maria Giovanna , Prati Carlo , Silos Moraes João Carlos
Published: August 2016

The aim of this work was to evaluate the setting time, adhesion, sealing ability, and ion release of a novel endodontic sealer (CEOE) and of the commercial Sealer 26® cement. The setting time was determined in accordance with ANSI/ADA specifications #57. The adhesion of the materials to the canal walls was evaluated through bond strength using the push-out technique. The sealing ability was assessed by fluid filtration measurements. The released ions of interest to be analyzed are OH1- and Ca2+. The concentration of hydroxyl and calcium ions was evaluated by pH measurements and atomic absorption spectroscopy technique, respectively. The data were analyzed statistically using the analysis of variance and the Tukey’s test. The results obtained showed that the setting time of CEOE cement is 35% shorter than of Sealer 26® and both cements meet the British Standard BS (1988) recommendation. No significant difference was observed in the bonding strength and permeability values for both cements. Statistically, the CEOE released more hydroxyl ions than Sealer 26® in the first 72 h, and more calcium ions in the first 48 h.
Deposition by Spray-Pyrolysis of Tin Oxide Doped with Fluorine Produced by Sol-Gel Method
Authors: Maia Jr. Paulo Herbert França , Marcone Lima Francisco , Cosmo de Sena Aline , Silva Álvaro Neuton , Mota Martins Felipe , Leite de Almeida Ana Fabíola , Freire Francisco Nivaldo Aguiar
Published: August 2016

Solar energy is one of the most important sources of renewable energy today. The production of electric energy is based on silicon cells, which are expensive and difficult to produce and therefore, New preparation methods, materials or approaches are needed. This work aims to deposit Tin oxide doped with fluorine, prepared by sol-gel, on a glass substrate using the spray pyrolysis technique. F-SnO2 (FTO) solution was synthesized by sol-gel method, employing NH4F and SnCl2 precursors in an ethanol solution. Before the formation of the gel, the solution was sprayed using a pistol aerographic, On a substrate at approximately 600oC. This process was repeated 50 times, and after that, the sample was cooled until room temperature inside the furnace. The obtained samples (substrates for the PV cell) present a resistance between 10 and 30 Ω. The energy dispersive x-ray (EDS) was used to confirm the presence of fluorine in the SnO2 network.
Facing up to (online) fashion and fads … Face-to-face contact is here to stay in M&E capacity building. Evidence from 35 National Evaluation Societies
Authors: Dewachter Sara , Holvoet Nathalie
Published: August 2016

Background: Over the years, Communities of Practice have gained popularity as a capacity-building method among Monitoring and Evaluation practitioners. Yet, thus far, relatively little is known about their effectiveness.Objectives: This article focuses on National Evaluation Societies as Communities of Practice that aim to contribute to the monitoring and evaluation capacity building of their members.Method: Drawing upon a survey of 35 National Evaluation Societies in 33 low- and middle-income countries, we explore to what extent capacity building efforts have been successful and what factors explain the relative success or failure in capacity building. We rely upon Qualitative Comparative Analysis as we are particularly interested in different pathways to ensure successful National Evaluation Societies.Results: Our findings highlight that regular face-to-face contact is a particularly important element. This does not entirely come as a surprise, as monitoring and evaluation capacity building often implies tacit knowledge that is most effectively shared face-to-face. Furthermore, capacity building in conducting and, particularly, using evaluations entails building networks among the monitoring and evaluation supply and demand side which can most easily be done through regular face-to-face interaction.Conclusion: Our findings are not only theoretically interesting, they are also policy relevant; they hint at the fact that in an era of quick advances in technology, investing in face-to-face contact among members remains important.
‘I know you can do all things’ (Job 42:2): A literary and theological analysis of Job’s testimony about Yahweh’s sovereignty
Authors: Boloje Blessing O. , Groenewald Alphonso
Published: August 2016

The article presents a literary and theological analysis of Job 42:2 as a fitting resolution of the conflicting engagement between Yahweh and Job, which enables both parties to preserve their integrity. The article examines Israel’s testimony about Yahweh’s sovereignty as a background, it analyses Job’s testimony in 42:2 and then demonstrates that this passage probes more deeply into the theology of creation – the inescapable purpose of what God does. The article shows that Job’s testimony about the sovereignty of Yahweh indicates an unusual personality and potent force that is manifested in the events of Job’s life as an agent whose sovereignty is remarkably unlimited. The substance of Job’s testimony this article proposes, produces a dynamic figure that has an overwhelming task at the centre stage of its subject’s well-being. This role, moreover, is the engine that drives Israel’s testimony; the splendour of Israel’s faith and the source of Israel’s life. This role is a theological datum of substance.
Presbyterian Indians in South Africa
Authors: Pillay Jerry
Published: August 2016

In this article the author traces the origins and development of Indians in the Uniting Presbyterian Church in Southern Africa. He acknowledges the work of the founder of the Indian Presbyterian work, the Rev. Joseph Prakasim, looks at the expansion of Presbyterianism among the Indian population in South Africa and shows how through various ministries these congregations contributed to the development of the Indian communities in South Africa, impacting on the country as a whole.
Televangelism: A study of the ‘Pentecost Hour’ of the Church of Pentecost
Authors: White Peter , Assimeng Abraham Anim
Published: August 2016

The liberalisation of the Ghanaian media since the 1990s has drastically changed the media landscape of Ghana and given rise to the use of the mass media for evangelism purposes. The advent of the mass media offered churches and televangelists a unique opportunity to fulfil the Great Commission, and it is the Pentecostals who continue to use it effectively. Many Ghanaian Pentecostal Churches in the past 20 years have made good use of the mass media (radio and television) for the propagation of the gospel. In this article the televangelism ministry of the Church of Pentecost, named ‘Pentecost Hour’, and how it has influenced the mission and discipleship agenda of the Church of Pentecost in their endeavour to participate in the missio Dei are discussed.
‘Something is recognised’: A liberal Protestant reflection on Erik Borgman’s cultural theology
Authors: Benjamins Rick
Published: August 2016

The Dutch Roman Catholic theologian Erik Borgman (1957), who developed a cultural theology, was appointed as a visiting professor at the liberal Protestant theological Mennonite Seminary in Amsterdam. In this article, his progressive Roman Catholic theology is compared to a liberal Protestant approach. The historical backgrounds of these different types of theology are expounded, all the way back to Aquinas and Scotus, in order to clarify their specific character for the sake of a better mutual understanding. Next, the convergence of these two types of theology in the twentieth century is explained with reference to the philosophy of Heidegger. Finally, the difficulties posed by postmodern philosophies to both a progressive Roman Catholic theology and a liberal Protestant theology are shown. It is asserted that both types of theology claim that the insights of their particular tradition can be relevant beyond this tradition to modern and postmodern humans.
‘Welc(h)omo Naledi’! What does our newest relative have to say to us?
Authors: Veldsman Daniël P.
Published: August 2016

The new hominin fossil called Homo naledi that was discovered 2 years ago in the Dinaledi Chamber (South Africa) was welcomed into the species of human relatives on 10 September 2015. Welcomed? Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa. Do, however, these bones represent a new Homo species? It is this question that I have tried to capture in my playful grammatically incorrect title ‘Welc(ho)mo Naledi’! However, it is not this question that I will endeavour to answer, but a very different theological implication. My aim in this article is definitely not to argue an opinion on the diverse question regarding the discovery of the fossil skeletons from the Dinaledi Chamber. My aim is related but different, much more modest, restricted and focused. It is to ask ‘on the other historic side’ (that is, beyond the fossil record!) of Naledi about human distinctiveness and symbolic behaviour, specifically on soteriology. Within the broader contemporary philosophical-theological discourses on anthropology and specifically the fundamental question, ‘Are we special?’, I would like ultimately to take on the intriguing theological implications for soteriology from the Naledi (and earlier) findings.
Partners in history: The Dutch Reformed Church and theological training at the University of Pretoria: 1938–2000
Authors: Van der Merwe Johan
Published: August 2016

The Faculty of Theology at the University of Pretoria celebrates its centenary in 2017. Theological training at the university started in 1917 when the Nederduitsch Hervormde Kerk van Afrika decided to train its own ministers. In 1937 the Dutch Reformed Church decided to establish a faculty of its own at the university. This led to a faculty with two sections: Section A for the Nederduitsch Hervormde Kerk and Section B for the Dutch Reformed Church. This was the situation until 2000 when the two faculties merged to become one. Although theological training by the Dutch Reformed Church only started in 1938, their faculty, Section B was an important partner through the 100 years of theological training. This article gives a chronology of the history of the Faculty of Theology Section B as partner in the history of theological training at the University of Pretoria.
Re-visiting the notion of Deep Incarnation in light of 1 Corinthians 15:28 and emergence theory
Authors: Bentley Wessel
Published: August 2016

Niels Hendrik Gregersen’s ‘Deep Incarnation’ is opening up possibilities for engagementbetween science and theology. Recent discoveries, like that of Homo naledi, raise questions abouthow inclusive a Christian doctrine of Incarnation is. Is Jesus only God incarnate for Homo sapiensapiens, or is the incarnation inclusive of preceding hominid species as well? Does the incarnationstretch beyond the hominid line? This chapter engages Gregersen’s understanding of DeepIncarnation in light of 1 Corinthians 15:28 and emergence theory. It proposes that there is a directcorrelation between worldview and how we believe in the inclusive nature of divine incarnation.
Diet and seasonal dispersal of extralimital giraffe at Sanbona Wildlife Reserve, Little Karoo, South Africa
Authors: Gordon Claire N. , Eichenberger Liesl , Vorster Paul , Leslie Alison J. , Jacobs Shayne M.
Published: August 2016

South African giraffe (Giraffa camelopardalis giraffa) have been introduced as an extralimital species to private farms in the Little Karoo on the basis of economic sustainability, and the need to create a competitive tourism product. However, little is known about the medium- to long-term impacts and ecological sustainability of such introductions. The diet of a population of giraffe on Sanbona Wildlife Reserve, near the town of Ladismith, was assessed via direct observations between January and October 2014, in order to determine their potential impact on the world’s most species-rich semi-desert, the Succulent Karoo. Unlike giraffe in their native range, the Sanbona population showed seasonal preference for browse species. Acacia karroo (sweet thorn) appears to be the preferred browse species during autumn and spring, with Schotia afra being the preferred species in winter, and no significant preference being shown in summer. Giraffe also appeared to seasonally move between catchments where tree species other than A. karroo occurs, especially during winter and spring when the tributaries of the Brak River, containing mixed Acacia with S. afra (karoo boer-bean) and Euclea undulata (small-leaved guarri), were visited with increasing frequency. These results largely confirm the importance of A. karroo as the main browse species in this environment but also suggest that other species may be important components of the diet of extralimital giraffe in the Little Karoo. On farms where A. karroo is dominant, supplementary feed may be needed when A. karroo browse is unavailable due to leaf drop.Conservation implications: Acacia karroo was the main browse species of extralimital G. c. giraffa at Sanbona Wildlife Reserve, but it switched to S. afra during winter. This suggests that an assessment of alternative food species forms part of suitability assessments for the introduction of extralimital G. c. giraffa for areas similar to Sanbona.
Fish communities of the Wilderness Lakes System in the southern Cape, South Africa
Authors: Olds Alexis A. , James Nicola C. , Smith M. Kyle S. , Weyl Olaf L.F.
Published: August 2016

The Wilderness Lakes System, a temporarily open and closed estuary with three associated lakes situated in the southern Cape region of South Africa, was sampled using a range of sampling gears to assess the fish community. A total of 25 species were sampled throughout the system, with the highest diversity in the Touw Estuary (23 species) and the lowest in Langvlei (11 species). Estuary-associated marine species (13 species) dominated species richness with smaller proportions of estuarine resident (7 species), freshwater (3 species) and catadromous species (2 species). Estuarine resident species dominated the catch numerically. The size–class distribution of euryhaline marine species indicated that upon entering the Touw Estuary as juveniles, the fish move up the system towards Rondevlei where they appear to remain. Three freshwater species were recorded in the system, all of which are alien to the Wilderness Lakes System. Decreasing salinity in the upper lakes appears to be a driving factor in the distribution and increasing abundance of the freshwater fishes. Sampling followed a drought, with the system experiencing substantially increased levels of mouth closure compared to a similar study conducted in the 1980s. The timing of mouth opening and the degree of connectivity between the lakes influence the nursery function of the system as a whole. Management actions need to focus on improving ecological functioning of this system, in particular how mouth opening is managed, to facilitate nursery function and limit the establishment of invasive species.Conservation implications: Key management actions are required to improve fish recruitment potential into and within the system. These include maintenance of adequate marine inflow through adherence to artificial mouth breaching protocols and improving connectivity between the lakes through sediment removal from localised deposition points within the connecting channels.
Comparison of nucleotide sequences of recent and previous lineages of peste-des-petits-ruminants viruses of sheep and goats in Nigeria
Authors: Mantip Samuel , Quan Melvyn , Shamaki David , Van Vuuren Moritz
Published: August 2016

Peste-des-petits-ruminants virus (PPRV) is a highly contagious, fatal and economically important viral disease of small ruminants that is still endemic and militates against the production of sheep and goats in endemic areas of the world. The aim of this study was to describe the viral strains within the country. This was carried out by collecting tissue and swab samples from sheep and goats in various agro-ecological zones of Nigeria. The phylogeny of archived PPRV strains or isolates and those circulating and causing recent outbreaks was determined by sequencing of the nucleoprotein (N)-gene. Twenty tissue and swab samples from apparently healthy and sick sheep and goats were collected randomly from 18 states, namely 3 states in each of the 6 agro-ecological zones visited. A total of 360 samples were collected. A total of 35 samples of 360 (9.7%) tested positive by reverse transcriptase–polymerase chain reaction, of which 25 were from oculo-nasal swabs and 10 were from tissue samples. Neighbour-joining phylogenetic analysis using Phylogenetic Analysis Using Parsimony (PAUP) identified four different lineages, that is, lineages I, II, III and IV. Interestingly, the Nigerian strains described in this study grouped in two separate major lineages, that is, lineages II and IV. Strains from Sokoto, Oyo, Plateau and Ondo states grouped according to the historical distribution of PPRV together with the Nigerian 75/1 strain of lineage II, while other strains from Sokoto, Oyo, Plateau, Akwa-Ibom, Adamawa, Kaduna, Lagos, Bauchi, Niger and Kano states grouped together with the East African and Asian strains of lineage IV. This finding confirms that both lineage II and IV strains of PPRV are circulating in Nigeria. Previously, only strains of lineage II were found to be present in the country.
Contraceptive practices among women seeking termination of pregnancy in one public hospital in Eastern Cape, South Africa
Authors: Oluwole Ebenezer O. , Skaal Linda
Published: August 2016

Background: There is significantly high contraceptive knowledge in South Africa, but the uptake of contraceptives is average to low with resultant soaring of unplanned pregnancy and rising statistics of termination of pregnancy (TOP) services. This study aimed to establish the contraceptive practices among women in the South African population seeking TOP in one public hospital in Eastern Cape, South Africa.Methods: A cross-sectional study was carried out among women seeking TOP in a women’s clinic. Self-administered questionnaires were used as data collection tool, and the data collected were entered into SPSS software for analysis, using descriptive statistics to calculate frequencies and percentages while chi-square test was used to determine the associations between the socio-demography and contraceptive practices of the participants.Results: Majority of the women were aged between 20 and 29 years, had secondary education, unemployed, single and resided in townships. Contraceptive uptake prior to termination of pregnancy (CTOP) among them was 44.1%, but 85.8% had good contraceptives knowledge. Their contraceptive practices are determined by partner’s opinion, source and availability of contraceptives, previous CTOP, side effect of contraceptives and having children. Age group, educational level and employment status were found to be related to the contraceptive practices of the participants but were not statistically significant.Conclusion: To reduce unplanned pregnancies and subsequent number of women seeking CTOP, the socio-economic factors associated with contraceptive practices as well as the programmes, policies and guidelines of contraceptives need to be improved on for any improvement on the factors determining contraceptive practices.
How to change organisational culture: Action research in a South African public sector primary care facility
Authors: Mash Robert , De Sa Angela , Christodoulou Maria
Published: August 2016

Background: Organisational culture is a key factor in both patient and staff experience of the healthcare services. Patient satisfaction, staff engagement and performance are related to this experience. The department of health in the Western Cape espouses a values-based culture characterised by caring, competence, accountability, integrity, responsiveness and respect. However, transformation of the existing culture is required to achieve this vision. Aim: To explore how to transform the organisational culture in line with the desired values. Setting: Retreat Community Health Centre, Cape Town, South Africa. Methods: Participatory action research with the leadership engaged with action and reflection over a period of 18 months. Change in the organisational culture was measured at baseline and after 18 months by means of a cultural values assessment (CVA) survey. The three key leaders at the health centre also completed a 360-degree leadership values assessment (LVA) and had 6 months of coaching. Results: Cultural entropy was reduced from 33 to 13% indicating significant transformation of organisational culture. The key driver of this transformation was change in the leadership style and functioning. Retreat health centre shifted from a culture that emphasised hierarchy, authority, command and control to one that established a greater sense of cohesion, shared vision, open communication, appreciation, respect, fairness and accountability. Conclusion: Transformation of organisational culture was possible through a participatory process that focused on the leadership style, communication and building relationships by means of CVA and feedback, 360-degree LVA, feedback and coaching and action learning in a co-operative inquiry group.