bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribological Properties of the ZrN Coatings by DC Magnetron Sputtering
Authors: Liu Chien Cheng , Liu Kuang I , Lin Hao Tung , Chou Yung Chih , Cheng Yung Mao , Lin Chih Lung
Published: January 2014

ZrN thin films were successfully deposited by DC magnetron sputtering on die steel substrates. The objective of this study was to investigate heat treatment on the microstructure, morphology, nanohardness properties determined by X-ray diffraction, field-emission scanning electron microscope (FE-SEM), nanoindentation, and pin-on-disk, respectively. The XRD result shows that ZrN has intensity of (111) and (200) peak after 400 °C for 1 h at lower nitrogen flow rates. The surface of coatings revealed smaller grains and smooth surface under heat treatment. ZrN coatings consisted of lower nitrogen flow rate had much lower friction coefficient, better mechanical properties by annealing treatment process.
Research on the Real-Time Property of TTCAN Protocol in Vehicle Communication Network
Authors: Li Xie
Published: January 2014

This paper introduces the time triggered bus technology in vehicle communication network application, the bus protocol project: exclusive time window, the window of time and idle time window is discussed. In the laboratory conditions, the different communication protocols and communication parameters can be easily realized, which can be used to analyze the CAN and TTCAN communication protocol and network load frame priority to the impact of delay time, and verify the correctness of the model.
A Kind of Diminishing Step Fruit Fly Optimization Algorithm
Authors: Hou Jun Yan , Wang Bing
Published: January 2014

Parameters of Support Vector Machine are playing an important part in learning performance and generalization capability. The randomness and blindness in selecting SVM model parameters artificially could be eliminated by using group intelligent optimizing algorithm. FOA is a kind of group intelligent optimization algorithm. It has some advantages such as global convergence, connotative parallelism and fast operating speed. However, its optimum efficiency is very sensitive to the length of fixed step. In the course of optimizing, if the step is oversize, it will have preferable global optimizing performance and weak local optimizing capability. On the contrary, if the step is undersize, the local optimizing capability would be powerful and it will have the most probability to lapse into local extreme value. Therefore, a kind of algorithm named Diminishing Step FOA is proposed, the step length minishes progressively along with the process of foraging. So that it would have preferable global optimizing capability in early stage and preferable local optimizing capability in later period. And then, a dynamic balance will be achieved between global and local optimizing capability. The experimental results show that the SVM model using DS-FOA has optimal forecast precision and effect.
The Research on the System of Talent Cultivation in State Key Laboratory
Authors: Fang Lu , Zhao Lian Rong
Published: January 2014

Talent is one of the key factors to determine the long-term development of the State Key laboratory. With the appearance of inadaptability and imperfection, the system of traditional talent cultivation should be combined with the characteristics of laboratory research personnel, establishing the people-oriented concept. This article, based on the management motivation reinforcement theory, combines with the current situation of key laboratories and strives to provide reference about the innovation of laboratory talent cultivation.
Phase Transformations and Magnetic Properties of Electroplating Ni-Co on Aluminium
Authors: Hu Yong Jun , Cao Dong , Li Xi Qiang , Zheng Hui Ting , Cheng Xiao Ling , Xiao Xiao Ting , Zhang Hai Yan , Li Feng
Published: January 2014

In this paper, Ni-Co coatings on Al foil were prepared by electroplating to obtain Al/Ni-Co composite. Phase transformations and magnetic property of Al/Ni-Co composite heated at 823 K for 80 h were investigated. The results showed that obviously exchanged zone in Al matrix exited and the thickness was about 2.5μm. Ni diffused into the Al easilier than Co. β phase (AlNi and AlCo) and γ phase (Al (Ni, Co) solid solution) of Co-Ni-Al formed during the annealing. The Ms of was decreased significantly when Al diffused into the NiCo alloy film and formed Ni-Al and Co-Al intermetallic compounds.
Effect of Recycled Coarse Aggregate on Recycled Concrete Properties and Study of Optimum Mixture Ratio
Authors: Ning Hai Long , Zhao Wen Feng , Liu Jian , Jiao Shao Peng , Wang Yi Xin
Published: January 2014

To study the effect of recycled coarse aggregate, water-cement ratio and mixture ratio on the physico-mechanical properties of recycled concrete, determine the finial optimum mixture ratio and physico-mechanical properties of recycled concrete with the optimum mixture ratio, physico-mechanical tests are done on recycled concrete and conventional concrete. Results show that with the replacement rate increasing of recycled coarse aggregate, the compressive strength and splitting tensile strength of recycled concrete increase and then decrease. It is feasible to develop the concrete with 100% replacement rate of recycled coarse aggregate. With an increase of recycled coarse aggregate replacement rate, dry shrinkage ratio of concrete increases gradually, but the increasing range has little effect on the concrete. The concrete strength of 28 days is linear with water-cement ratio with the correlation coefficient is 0.98763. Taking appropriate mix design, the physico-mechanical properties of recycled concrete will surpass or be equivalent to those of conventional concrete. Recycled concrete of the optimum mixing rate is the high strength with lower brittleness.
Fibrous Material Surface Reflectance Analysis
Authors: Say Ong Tee , Sauli Zaliman , Retnasamy Vithyacharan , Nor Nur Izza Mohd , Anwar K. , Abdullah Nooraihan
Published: January 2014

The light inspection on surface finishing of most product measurement is an important feature in the industries. In this study, a lab module tester for examination on the different type quality of tissue paper quality was done. The light reflectance element was used in this study to differentiate the quality of tissue paper. The laser diode and photodiode was used as manipulator to differentiate the tissue paper and photo detector to detect the reflected light from the surface of tissue paper. The both of laser diode and photodiode were placed in a light box. Different level of intensity reflected from the surface material will have different voltage output. The result showed that the total ply high quality tissue paper has a higher reflected voltage output compared to low quality tissue paper.
Research of Calibration Curves NMR Relaxation Times of Nanoparticles Gadolinium Oxide
Authors: Yang Chun Lin , Ou Mei Gui , Zeng Jia , Yang Xiu Qun
Published: January 2014

In this paper, a method of assay based on NMR (Nuclear Magnetic Resonance) measurements was developed. A protocol for the dissolution of gadolinium oxide cores and calibration curves were established for Nanoparticles gadolinium oxide. After optimization this method was used for several applications such as checking the concentration in colloids after dialysis or controlling the concentration and the form (oxides or free ions) of lanthanides after in vivo injection. The Experiments showed the samples did not present any suspension or deposit after the dissolution treatment, The concentrations calculated from relaxation measurements are very close to the concentrations measured . According to measure relaxation times T1 and T2, we can approximately determinate the gadolinium concentration. .
Study of Heat Treatment on Phase Transformation of Ni-44,8 wt% Ti Ribbons Obtained by Melting Spinning
Authors: Anselmo G.C.S. , de Castro Walmam B. , de Araújo C.J.
Published: January 2014

Shape memory alloys (SMAs) represent a unique class of materials that undergo a reversible phase transformation (martensitic transformation) allowing these materials to display dramatic pseudoelastic stress-induced deformations and shape memory temperature-induced deformations that are recoverable. Among the known shape memory alloys, NiTi is the most commonly used because of its excellent mechanical properties, corrosion resistance and biocompatibility. This work studied the influence of two parameters of heat treatment (temperature and time) on martensite phase transformation temperature (MS) in a Ni-Ti (48,8 wt % Ti) shape memory alloy, using a factorial design (22). The aim of our research was to establish a mathematic model of the technological process, useful for controlling of martensite phase transformation temperature. The two factors, temperature and time, have an important influence on MS.
Heat Treatment as an Alternative to Brass Warping
Authors: Wilborn M.M. , Korb Matias Angelis , Ludwig G.A. , Fhur L.T. , Malfatti C.F. , Mozetic H. , Schneider E.L. , Oliveira C.T.
Published: January 2014

This paper proposes the reduction of warping after the machining of alloys of brass with lead. For this purpose the brass alloys were submitted to heat treatment and analyzed before and after the machining process. Elongation and dimensional variation, microstructure and chemical microanalysis of the samples were assessed. It was found that warping may be related to the chemical composition of the alloy, added to the rolling process used to obtain the material to be machined. The results showed that heat treatment before the machining process eliminates the warping seen in the workpieces.
Structure and Properties of Quenched and Cyclic Compressed Ti-Mo Alloys
Authors: Silva Marcia Almeida , Matlakhova Lioudmila Aleksandrovna , Monteiro Sergio Neves , Goncharenko Boris Andreevich , Zabolotnyi Vladimir Tikhonovich
Published: January 2014

The present work analyses the microstructure of quenched and cyclic compressed Ti-Mo alloys that possess non-elastic effects and reversible martensitic transformations. Quenched samples were subjected to cyclic compression tests up to 10% strain per cycle. The structure of these alloys, composed of β (BCC) phase with minor participations of α (HC); α (orthorhombic); w (HCC) and α (HC) phases, apparently had suffered a gradual α α α β transformation with increasing Mo content. It was found that the cyclic compression did not promote relevant alterations in the phase composition. Both the alloys electrical resistivity and microhardness were found to be sensitive not only to the Mo content but also to the accumulated deformation. Alloys with 8 and 10% Mo content exhibited low elastic modulus combined with low residual strain, which indicates a possible superelastic behavior.
Influence of the Addition of Polypropylene and Compatibilizer in PA6 Membranes Obtained by Phase Inversion
Authors: Bezerra Elieber Barros , Leite A.M.D. , Araújo E.M. , Melo T.J.A. , Cunha C.T. , Maia Larissa Fernandes
Published: January 2014

Polymer blend is the name for the physical mixture of two or more polymers and/or copolymers, and this allows the obtention of new materials with superior properties to those of the pure components. The blends have been used in obtaining membranes in order to improve the barrier properties so that it can separate two phases totally or partially, restricting the transport of one or more chemical species. In this work, polymer membranes were obtained from blends of PA6/PPgAA and PA6/PP/PPgAA by phase inversion method and were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was observed through the diffractograms that there were no significant variations in the characteristic peaks of PA6, and through SEM, it was observed the formation of microporous asymmetric membranes, where they showed a surface with higher porosity to the binary and ternary blends and presented smallest pore diameter for binary blends.
Calcination Influence on the Structure and Morphology of Zirconia Synthesized by Combustion Reaction
Authors: Silva F.N. , Dantas J. , Silva A.S. , Pallone E.M.J.A. , Costa A.C.F.M.
Published: January 2014

This research aims to synthesize ZrO2by combustion reaction in batches of 15 g of the product and to evaluate the calcination influence on the structural and morphological characteristic about synthesized sample. For the synthesis of ZrO2, the stoichiometry of phase was established in accordance with the propellants and explosives chemical concept, whereas the stoichiometric coefficient φ =1. After the synthesis, the sample as synthesized was calcined at 600 and 700°C and subsequently characterized by XRD, SEM, textural analysis (BET) and FTIR. The results have shown to the sample as synthesized and then calcined at 600°C the majority phase formation of orthorhombic zirconia with monoclinic phase dashes. The temperature increase to 700°C, has been transformed a part of the orthorhombic ZrO2to a monoclinic phase, contributing to a surface area reduction of the samples, showing irregular agglomerates in morphology, with adsorption/desorption isotherms type IV and mesoporosity characteristic.
Technology for Coke Production in Tunnel Kiln from Compacted Coal Powder
Authors: Gislon Edivelton Soratto , Luza André Luís , Fabris Débora Cristina Niero , Machado Morgana de Medeiros , Montedo Oscar Rubem Klegues
Published: January 2014

Coal extraction produces large amounts of wastewater containing coal powders, which could be used to produce coke. In this case, binder materials should be used to allow compression capacity to the mixture. This work aims to study the effect of binder addition in mixtures of coals containing different contents of coal powders to obtain coke. Compositions containing different amounts of coal powders were prepared by varying the nature and the contents of the binders to allow the pressing of powders. Study of the thermal behavior of these compositions was performed. The composition that showed the best results was then homogenized, pressed and heat treated. The final composition showed FSI about 4.5 and compressive strength of 5 MPa, demonstrating high potential for coke production from coal powder.
Characterization of Banana Fibers Functional Groups by Infrared Spectroscopy
Authors: Monteiro Sergio Neves , Margem Frederico Muylaert , Loiola Rômulo Leite , de Assis Foluke Salgado , Oliveira Michel Picanço
Published: January 2014

A number of methods are available for characterization of the structural, physical, and chemical properties of natural fibers. Various methods are used for fiber identification like microscopic analysis, solubility, heating and burning technique density, staining etc. End-use property characterization methods often involve use of laboratory techniques which are adapted to simulate actual application as composite reinforcement. One of the techniques used on this kind of studies is the infrared spectroscopy. In fact, Fourier Transform Infrared (FTIR) spectroscopy is a valuable tool in the determination of functional groups actively interacting within a fiber. In this work, the banana fiber was evaluated by FTIR to reveal these functional groups and compare to similar works on other different types of banana fibers.
Dynamic-Mechanical Behavior of Malva Fiber Reinforced Polyester Matrix Composites
Authors: Monteiro Sergio Neves , Muylaert Margem Frederico , Margem Jean Igor , Martins Lucas Barbosa De Souza , Oliveira Caroline Gonçalves , Oliveira Michel Picanço
Published: January 2014

Dynamic-mechanical (DMA) tests have not yet been conducted in malva aligned fiber reinforcing polymeric composites. In this work, the temperature dependence of the DMA parameters in polyester matrix composites reinforced with up to 30% in volume of continuous and aligned malva fibers was investigated. These parameters were the storage and the loss modulus as well as the tangent delta. The investigation was conducted in the temperature interval from-20 to 180°C using a Perking-Elmer DMA equipment operating in flexural mode. The results showed that the incorporation of malva fibers tends to increase the viscoelastic stiffness of the polyester matrix. Sensible modifications in the glass transition temperature and the damping capacity of the structure were found with the amount of fiber in the composite. The molecular mobility of the polyester matrix is affected by its interaction with the malva fibers.
Polyurethane Composite Membranes
Authors: Sinji Harada Nikolas , de Araujo Renata Bastos , de Souza Marcelo Augusto Vieira , de Santa Maria Luiz Claudio , Wang Shu Hui
Published: January 2014

Fibrous nanostructured polyurethane composite membranes were developed using electrospinning process. Membranes of polyurethane having silver and zinc oxide as additives were prepared by electrospinning of solutions having dimethylformamide (DMF) or its mixture with tetrahydrofuran (THF) (50:50 volume ratio) as solvent. Morphology of the fibers was characterized by using optical microscopy and scanning electron microscopy, showing fiber diameters from 200 to 800 nanometers. Antibacterial properties were tested by eluting solutions of E.coli at different concentrations through the membranes.
Dynamic-Mechanical Analysis of Polyester Composites Reinforced with Giant Bamboo (Dendrocalmus giganteus) Fiber
Authors: Monteiro Sergio Neves , Margem Frederico Muylaert , de Souza Martins Lucas Barboza , Loiola Rômulo Leite , Oliveira Michel Picanço
Published: January 2014

To investigate the variation with temperature of the dynamic-mechanical parameters for the polyester matrix composites incorporated with up to 30% in volume of giant bamboo fiber was the motivation of this work. The analyzed parameters were the storage modulus, the loss modulus and the delta tangent. The investigation was conducted in the temperature interval from 25 to 195°C in a DMA equipment operating at 1 Hz of frequency under a flow of nitrogen. The results showed that the incorporation of long and aligned giant bamboo fibers tends to increase the viscoelastic stiffness of the polyester matrix. By contrast, only minor changes occurred in both the glass transition temperature and the damping capacity of the structure as measured by the tan δ peaks. These are indications that the polyester molecular mobility is not sensibly affected by interaction with the bamboo fibers in the composites.
Characterization of Curaua Fibers by Infrared Spectroscopy
Authors: Monteiro Sergio Neves , Margem Frederico Muylaert , Tonini Simonassi Noan , Loiola Rômulo Leite , Oliveira Michel Picanço
Published: January 2014

Natural fibers obtained from plants are being investigated as possible engineering materials with application in polymer composite reinforcement. For instance, the lignocellulosic fibers extracted from the leaves of the curaua plant (Ananas erectifolius) display a reinforcement potential owing to their relatively high strength. However, the curaua fiber has a poor adhesion with the polymeric matrix. In order to understand the curaua fiber interaction with a polymer matrix, the physical and chemical characteristics need to be evaluated. Among these characteristics, the Fourier transform infrared spectroscopy (FTIR) provides relevant information about the functional molecular groups and their possible interaction. Therefore, the objective of the present work was to analyze the FTIR of curaua fibers by means of transmittance spectrum obtained in the FTIR method with a 60o angle. The results showed peaks corresponding to specific molecular interaction that are discussed and compared to other results.
Fabrication of Artificial Stone from Marble Residue by Resin Transfer Molding
Authors: Ribeiro Carlos Eduardo Gomes , Rodríguez Rubén Jesus Sánchez , Vieira Carlos Maurício Fontes , Atem Carvalho Eduardo , Cândido Verônica Scarpini , Monteiro Sergio Neves
Published: January 2014

Artificial stones have recently been worldwide commercialized but are still not produced in Brazil. This has motivated efforts for the local fabrication of a similar stone. Thus, an artificial ornamental stone (AOS) was fabricated by means of a resin transfer molding (RTM) process. Marble residues were placed inside a hermetic mold under vacuum. A still fluid polyester resin, already mixed with a catalyst and a thinner, was injected into the mold. After curing, the density and water absorption of the AOS were evaluated. The material was also subjected to both compression and bend mechanical tests. The AOS microstructure was analyzed by scanning electron microscopy, which was then related to the obtained physical and mechanical properties.
Preparation of Biodegradable Polymer Nanocomposites and Vermiculite Clay by Melt Intercalation Technique
Authors: Barbosa Renata , Alves Tatianny Soares , Morais Dayanne Diniz Souza , Carvalho Laura Hecker , Pereira Osanildo Damião
Published: January 2014

The consumption of plastic products over the years has been producing large numbers of waste material, which accumulate by landfill generating considerable environmental problems. Among biodegradable polymers, there is the PHB (poly-3-hydroxybutyrate), which has attracted more attention once it is obtained from renewable sources. This study aimed to prepare biodegradable nanocomposites by melt intercalation of PHB polymer in the natural vermiculite clay, in the ratios of 1, 3 and 6 wt%. The nanocomposites were obtained in an internal mixer coupled to a torque rheometer by Haake-Blucher, operating at 170°C, 50 rpm for 10 minutes. The material was triturated and then films were molded by compression under the conditions: 3 tons at 170°C for 3 minutes. The films were characterized by X-ray diffraction (XRD) and Infrared (FTIR). These analyzes were used to evaluate the intercalation and / or exfoliation of nanocomposites. In general, results indicated changes in structure as a function of clay content employed in the systems of PHB / vermiculite.
Corrosion Resistance of Hybrid Films Applied on TiN Plate: Precursor Solution Acidified with Hydrochloric Acid
Authors: Kunst Sandra Raquel , Ludwig Gustavo Alberto , Oliveira Cláudia Trindade , Santana Joseane , Sarmento Victor Hugo Vitorino , Malfatti Célia de Fraga
Published: January 2014

The aim of this work is to coat tin plate with a hybrid film obtained from a sol consisting of alkoxide precursors: 3 - (trimethoxysilylpropyl) methacrylate (TMSM), poly (methyl methacrylate) PMMA with and without tetraethoxysilane (TEOS) addition. The pH = 3 was adjusted with hydrochloric acid. The films were obtained by dip-coating process, cured for 3 hours at 160 ° C, and characterized for their electrochemical behavior. The hydrophobicity of the film was determined by the contact angle measurements and its morphology was evaluated by SEM. Results showed that the hybrid films studied presented good performance concerning their corrosion resistance in tin plate. Besides the addition of TEOS, it has contributed to the increase of the film thickness, however at the same time promoting the crack formation, which compromises the corrosion resistance of the coated tin plate.
Strontium Titanate Ceramics Obtained by Conventional and Microwave Methods
Authors: Chaves André Silva , Berti Thalita Gonçalves , de Andrade Raponi Olívia , Gelfuso Maria Virginia , Thomazini Daniel
Published: January 2014

Thermoelectric materials are able to generate an electric potential when subjected to a temperature gradient. The efficiency of this conversion is based on the value of the figure of merit (ZT) of the material. One way to increase the value of ZT is producing nanostructured ceramics, because it should interfere in the thermal conductivity of the material. SrTiO3is also a thermoelectric oxide material, due it n-type semiconductor nature. In this study, ceramic powders were obtained by solid-state reaction, mixing stoichiometric amounts of titanium oxide (TiO2) and strontium carbonate (SrCO3) in a polypropylene jar with zirconium balls for three hours. This mixture was calcined at 1000°C for 2 hours. These samples were pressed into pellets with 12mm in diameter and were sintered under different conditions: by a conventional method in an resistive oven at 1400o C for 3 hours and in a microwave oven at temperatures of 1220°C 1350°C 1375°C 1400°C and 1450°C for thirty minutes. The powders were subjected to structural and ceramics were subjected to microstructural characterizations.
Effect of Microwave Power in Obtaining Ferrite Nanopowders Synthesized by Combustion
Authors: da Silva Mirele Costa , Silva A.T.C. , Costa Ana Cristina F. Melo , de Freitas Normanda Lino
Published: January 2014

The search of variations in the methodology for obtaining nanoferrites has attracted the interest of researchers in search of better results with regard to the structure and morphology of these materials. This study evaluates the effect of microwave power (50 and 70 W) in the structural and morphological characteristics of NiZn ferrite, using aniline as a fuel for combustion reaction. The aluminas were characterized by X-ray diffraction and scanning electron microscopy. The results showed that only the variation in microwave power is sufficient to change the structure of nanoferrites. The sample synthesized in power of 50 W was presented monophasic, illustrating the ferrite phase with crystallite size of 50.04 nm; and for 70 W, it was appeared, besides the ferrite phase, hematite and zinc oxide with a crystallite size of 17.07 nm. The morphology did not change significantly, the nanoferrites showed particles with similar geometry.
Influence of Clay Content in Membrane Morphology of Polymer Polyamide 6.6/Montmorillonite Clay
Authors: Kojuch Luana Rodrigues , de Medeiros Keila Machado , Araújo Edcleide Maria , Lira Hélio de Lucena
Published: January 2014

Membranes can be defined as a barrier that separates two phases and is widely applied in industrial separation processes. The development of membrane separation processes (PSM) has the major advantage of phase change without separation of components, besides selectivity and simplicity of operation. The addition of mineral fillers in polymers is intended for the cost reduction and increase in rigidity of the materials. When these loads have sizes of nanometric dimensions, this system is called nanocomposites, which exhibit improved properties compared to the pure polymers or conventional composites. Microporous membranes were obtained from polyamide 6.6 nanocomposites of varying amounts of regional montmorillonite clay through the immersion-precipitation process. In general, the membranes showed a filter skin, which contains very small pores and a porous layer, with variations in microstructure, detected by scanning electron microscopy (SEM).
Nanocomposites Obtained by Montmorilonite Clay Additivation in P3 (HB-8%HV)
Authors: da Silva Emilene Rita Pimental , Rodriguez Ruben Jesus Sanchez , Miguens Flavio Costa , Souza Djalma , Monteiro Sergio Neves , Candido Veronica Scarpini
Published: January 2014

Modified montmorilonite additivated films of poly 3 (hydroxybutyrateco-8%-hydroxyvalerate) were formulated by solvent evaporation technique and then characterized by means of X-ray diffraction, scanning electron microscopy, atomic force microscopy and scanning differential calorimetry. A preliminary characterization using these analyses revealed the formation of nanocomposites with partially exfoliated and interlayered structures. These nanocamposites display changes in the crystalline structure of the precursor biodegradable polymer.
Evaluation of Attapulgite Clay Content from Piauí in Sorption Characterization of Water in the Polyester Matrix Composites
Authors: Barbosa Renata , Alves Tatianny Soares , Júnior Celso Hartmann , Cadah Gabriel Neiva
Published: January 2014

The physico-chemical characteristics of attapulgite clay confer appropriate properties to their different industrial uses, such as: Drilling fluid, bleaching of vegetable oils, mineral and animal grease and oil absorbents, pet waste absorbents (pet litter), purification of drinking water etc. The aim of this study was the chemical modification of attapulgite originally from state of Piauí, for applications in polyester-based composites. The unmodified and modified clay were characterized by X-ray diffraction (XRD). In order to evaluate the interaction of clays with organic solvents, the test of Foster swelling with gasoline, diesel and toluene was conducted. The polyester resin-based composite and clay unmodified and modified in different percentages were molded by hand lay up technique and they were characterized by water sorption.
La, Sr and Co Based Coatings Obtained on Ferritic Stainless Steel by Dip-Coating Technique
Authors: Korb Matias Angelis , Atolini Micael , Oliveira Junior José Carlos , Savaris Israel Durli , Ludwig Gustavo Alberto , Malfatti Célia de Fraga
Published: January 2014

The ferritic stainless steels have been used in applications where suitable properties are required at high temperatures. These metallic materials are applied, for example, as interconnects in ITSOFC fuel cells (600-800 °C).The aim of this work is to produce a La, Sr and Co based coatings using the dip-coating and spray pyrolysis techniques, on an AISI 430 ferritic stainless steel. These coatings are known for acting as barriers, increasing the oxidation resistance when applied on stainless steel at high temperatures. The obtained coatings were heat treated at 800 °C for 120 min, seeking the formation of La0,6Sr0,4Co,and, then characterized regarding their morphology and microstructure using scanning electron microscopy (SEM) and X-ray diffraction. The results showed that the coatings obtained by spray pyrolysis covered regularly the surface while the ones obtained by dip-coating exhibited some crack formation.
Platinum-Free Catalysts for Alkaline Polymer Electrolyte Fuel Cells
Authors: da Silva Elen Leal , Correa P.S. , de Oliveira F. , El Sheikh A. , Radtke C. , Malfatti Célia de Fraga
Published: January 2014

Platinum is known as the best catalyst for fuel cells reactions, because it presents the best catalytic activity and stability, mainly in acidic media. However, due to the high cost of platinum and its lower availability, the development of platinum-free catalysts for Alkaline Polymer Electrolyte Fuel Cells has been proposed. This work aims to compare catalysts characteristics obtained from two different synthesis methods. Ni catalysts were obtained by the impregnation/reduction method and by electroless deposition. The morphology of the electro-catalysts obtained were characterized by SEM-EDS and the electrochemical behavior was evaluated by Cyclic Voltammetry. And the composition of the catalysts obtained by the impregnation/reduction method was analyzed by Rutherford Backscattering Spectroscopy. The results obtained showed that the catalyst elaborated by the impregnation/reduction method developed higher current densities values than the catalyst elaborated by electroless deposition.
Physical and Microstructural Characterization of Cathode, Composite Cathode and Electrolyte Ceramics to ITSOFC
Authors: Vargas Reinaldo Azevedo , Bonturim Everton , Andreoli Marco , Chiba Rubens , Seo Emília Satoshi Miyamaru
Published: January 2014

The (La0.60Sr0.40)(Co0.20Fe0.80)O3-δ - LSCF, (Ce0.90Gd0.10)O1.95 - CGO composites and LSCF were deposited by wet powder spraying deposition method for the purpose of investigating their potential use in Intermediate Temperature Solid Oxide Fuel Cells. The interlayers are necessary between CGO electrolytes and LSCF cathodes in order to improve the performance of these materials. LSCF powders synthesized by citrate technique were calcined at 900 °C for 4 h and, their LSCFCGO composites and LSCF suspensions deposited on CGO substrate and, sintered in 1100 °C for 1 h, were formed pseudo-perovskite. The ceramics materials were analyzed by X-ray diffraction (XRD) and chemical composition of different half-cells layers by scanning electron microscope with energy dispersive (SEM-EDS). The results are in agreement with the literature and indicate that route studied is adequate for crystal structures formation compatible with films the 35 μm thick total for study of conductivity between the cathode and the electrolyte.
Effect Polymeric Modifier (Biostrength B150), and Organoclay on Properties of Poly(lactic acid) - PLA
Authors: da Cunha Bartira Brandão , Lima J.C.C. , Silva T.R.G. , Araújo E.M. , de Mélo T.J.A.
Published: January 2014

In recent years the search for biodegradable polymers has excelled due to environmental issues. Among the biodegradable polymers from renewable sources, the poly (lactic acid) - PLA is one of the most widely used commercially, and several researches are being developed in order to improve their properties and thus increase its commercial applicability. Thus, this work aims to study the effects of incorporating polymer modifier (MBS Copolymer, Biostrength 150 - B150) and organoclay (Brasgel PA) in the properties of PLA. The study was conducted in two stages: with and without clay, and both with the B150. The concentrations used were 90/10 (PLA / modifier) and 3pcr (parts per hundred resin) of organoclay. The results showed that the mechanical properties of tensile and impact PLA significantly improved by using the polymeric modifier, indicating a gain in impact strength without a significant loss in modulus of elasticity.
Influence of Poly(Vinyl Butyral) on the Dynamic-Mechanical and Mechanical Properties of Polypropylene/Wood Flour Composites
Authors: Costa Lidiane C. , Ambrósio José Donato
Published: January 2014

This study reports the influence of recycled poly (vinyl butyral) (PVB) in dynamic mechanical and mechanical properties of polypropylene (PP)/wood flour composites prepared in a twin screw extruder. After extrusion, the PP/wood flour composites were injection molded to obtain specimens for tensile, flexural, impact and dynamic mechanical (DMA) tests. The morphology of the composites was analyzed by scanning electron microscopy (SEM). The addition 10 wt% of PVB in PP/wood flour composite reduced from 5°C to-10°C the β transition (glass transition) peak temperature of the loss modulus. In a temperature range between 40°C and 100°C the composites containing PVB presented the highest peak in the loss modulus. The most intense tan delta peaks between 50°C and 100°C for composites containing PVB were attributed to the combined effects of PP α transition with the PVB glass transition temperature. The PP/wood flour composites with PVB presented a tendency to increase the absorbed energy by impact.
Recycling of Benefited Blast Furnace Sludge into Red Clay Ceramic
Authors: Vieira Carlos Maurício Fontes , Monteiro Sergio Neves , Abreu Mariana Miranda , Riter Aline Vieira , Vernilli Fernando , Candido Veronica Scarpini
Published: January 2014

The blast furnace sludge is a waste generated after the washing step of the blast furnace gas. The reuse of this waste in the steelmaking process itself is quite problematic. This study aims to analyze the possibility of the incorporation of a type of blast furnace sludge, benefited by a process that uses helical separators, into red ceramic. Specimens were prepared by uniaxial pressing at 20 MPa and then fired at 750°C and 950°C. The evaluated technological properties were linear shrinkage, water absorption and flexural rupture strength. The results showed that the benefited blast furnace sludge significantly influences the evaluated properties, by impairing the linear shrinkage and the water absorption but improving the mechanical strength.
Physical-Mechanical Characteristics in Masses for White Ceramics Obtained with Flat Glass Waste
Authors: Porto Valdênia Souza , de Araújo A.M.B. , Cavalcanti M.S.L. , Morais C.R.S.
Published: January 2014

The production of urban solid wastes has grown surprisingly in last years, turning into one of biggest challenges for the contemporary society. Among these wastes, the glass waste can be highlighted bearing in mind that, for being totally returned to the productive chain without any loss of mass in the material, it has been receiving several incentives to help on development of alternative and green technologies which aim an adequate destination to this kind of material. Thereby, this research proposes the use of the flat glass waste like a flux, in a partial replacement to the feldspar, in the composition of masses for white ceramics, aiming to obtain products with physical-mechanical similar properties to the industrial products. To do this study, standard specimens were initially prepared, each one with different percentages of glass, to then be burned under temperatures between 1200 and 1250 degree Celsius. Later, the following tests were made: flaring color, linear retraction, apparent porosity and rupture module to flexion in three points, according to the ABNT/NBR 15097/2004 rules. The obtained values were compared with the suggested values for industrial masses, confirming the possibility to apply flat glass waste like a flux in masses to white ceramics, as an alternative to reuse of these materials.
Reuse of Special Glass Waste Like a Flux in Masses for White Ceramics
Authors: de Araújo Angela Maria Barbosa , Porto V.S. , Cavalcanti M.S.L. , Morais C.R.S.
Published: January 2014

The accumulation of garbage in urban centers is, undoubtedly, one of the major environmental problems of today. The high costs of implementation and maintenance of collection systems and garbagess treatment, have often,taken to failure of government attempts to resolve this issue.
Characterization of Asphalt Mix Formulated from Equations of Packing
Authors: Maestrelli Sylma Carvalho , Dezorzi Junqueira Amanda , de Oliveira Gonçalves Felipe , Ferreira André Sances , Campos Maria Gabriela Nogueira
Published: January 2014

Beginning during the decade of 1920, the Brazilian highway system became the main way of transportation in the country, fomenting the search for asphaltic mix with better mechanical properties and resistance to the weather variations. The asphaltic mix is formed by minerals aggregates and binder (PAC Petroleum Asphaltic Cement). The aggregates are responsible for supporting the traffic weight and stability. The PAC is responsible for the attachment between the constituent particles and impermeable state. In this work it was investigated the formulation of asphaltic mix starting from the packing equations of the particles: Andreasen, Alfred and Alfred Inverted. It was produced bodies of proof varying the proportions of the aggregates and fillers, keeping constant the PAC (5% in weight) and the results were compared to an industrial standard formulation. The values obtained are in accordance with the DNIT norms, indicating that the equations of packing can be applied to the formulation of asphaltic masses.
Kaolin Residue as an Alternative Binder for Grout Seat and Revetment
Authors: Beltrão S.L.D , Severo C.G.S. , Bezerra Izabelle Marie Trindade , Lira B.S. , Ferreira H.C. , Neves G.A.
Published: January 2014

The kaolin residue presents in its composition significant levels of sílica and alumina, making it a material with chemical and physical properties appropriate to use as an alternative material with pozzolanic characteristics in substitution to the cement for grout utilization. Thus, this work aimed evaluate the influence from the addition of different amounts of kaolin residual calcined in partial substitution of Portland cement on grout in dash 1:2:6 (cement+%residue:lime:sand). It was evaluated grouts with and without residue substitution in the strengths of 0%, 5% and 30%, through resistor the simple compression at 30, 60 and 90 healing days. The results of resistor from the grouts were over the one required by NBR 13281 [, classifying them as type I e II.
Effect of Reaction Temperature in the Alumina Preparation by Combustion in a Muffle Furnace
Authors: da Silva Mirele Costa , Costa Ana Cristina F. Melo , Lira Hélio Lucena , de Freitas Normanda Lino
Published: January 2014

The aim of this study is to evaluate the effect of temperature during the synthesis of alumina by combustion in a muffle furnace. The alumina was characterized by X-ray diffraction, particles size distribution and scanning electron microscopy. The results showed that the synthesis temperature of the alumina can affect the structure of the produced samples. The size distribution of the median particle diameter reached higher value for the alumina synthesized at 500°C with 16.07 μm, the range of the total distribution of particles is introduced to the large alumina synthesized 500 and 600°C and close synthesized when 700 and 800°C. The phase of the alumina was identified only after the synthesized sample at 800°C with crystallite size of 22.16 and 6.75 μm synthesized samples 800 and 900°C, respectively. With respect to morphology, increased synthesis temperature was not enough to significantly change.
Use of Ash from Coffee Wood into Clayey Ceramic
Authors: Silva dos Santos Bianca , Candido Veronica Scarpini , Monteiro Sergio Neves , Vieira Carlos Maurício Fontes
Published: January 2014

This work has as its objective to evaluate effect of the incorporation of an ash, obtained from burning wood from coffee plant, in the physical and mechanical properties of incorporated clayey ceramic. The ash has undergone characterization tests by the techniques of XRF, DTA / TG and XRD. Formulations were prepared with 5, 10, 20 and 30 wt% of ash incorporated into clay bodies that were then homogenized, dried and finally moistened. Rectangular test specimens were prepared by uniaxial pressing in a steel mold at 20 MPa, followed by firing at 700 °C. The fired ceramics were subjected to physical and mechanical tests for determining the bulk density, linear shrinkage, water absorption and tensile strength. The results indicate that the ash is composed predominantly of calcium, magnesium and potassium oxides. The incorporation of ash up to 20 wt% decreased the water absorption and notably increased the ceramic mechanical strength in the temperature investigated.
Study of Compatibility between Organoclays and Organic Dispersant Media through Foster Swelling
Authors: da Silva Isabelle Albuquerque , Costa Danubia Lisbôa , Cardoso M.A.F. , Figueirêdo J.M.R. , Neves G.A. , Ferreira H.C.
Published: January 2014

Foster swelling is one of the methods used to determine the compatibility between organoclays and organic dispersant media, improving the quality of organoclays. The need for replacing imported clays by national ones for the oil industry has recently resulted in the discovery of new deposits of smectites in the cites of Cubati and Pedra Lavrada, PB, reflecting great social and economic effects for that region. So, the objective of this work is to obtain organoclays from smectites from Pedra Lavrada, PB, aiming at the study of how to make these clays suitable with some organic dispersant media through Foster swelling. After organofilization, the clays were characterized by X-ray diffraction and Foster swelling. The results pointed that some media are compatible with organoclays, being diesel, kerosene and varsol the descendant order of compatibility between the clays and the organic media.
Study of the Rheological Properties of PP/Clay Systems under Steady and Oscillatory Shear Flows
Authors: Xavier Pablícia Fernanda Sousa Pires , Agrawal Pankaj , Brito Gustavo Figueiredo , da Cunha Bartira Brandão , Alves de Mélo Tomás Jeferson
Published: January 2014

In this work, polypropylene (PP) and organophilic clay composites without and with PPgMA compatibilizer were obtained. The organoclay was incorporated into the PP matrix at concentrations of 0.5, 1.0, 3.0, 5.0 and 10 phr in order to obtain composites without compatibilizer. In the systems with compatibilizer, concentrations of 0.5 and 1phr of the organoclay were used. The systems were characterized by rheological measurements under steady and oscillatory shear flows. In the rheological characterization, it was observed that the viscosity and storage modulus at low frequencies increased with the increase in the clay content and with the compatibilizer. These results are relevant in the evaluation of the influence of the compatibilizer in the processability and in the degree of clay dispersion.
Weibull Analysis to Characterize the Diameter Dependence of Tensile Strength in Sugarcane Bagasse Fibers
Authors: Candido Verônica Scarpini , Oliveira Michel Picanço , Gouvêa Raissa de Almeida , Martins Amanda Luiza Bezerra S. , Monteiro Sergio Neves
Published: January 2014

Fibers obtained from de sugarcane bagasse are being investigated as possible engineering materials. Their application as reinforcement of polymer composites is of interest due not only to environmental benefits associated with a waste recycling but also to their biodegradable and renewable characterisitics. Since it is known that many lignocellulosic fibers present a tensile strength inverse dependence with the diameter, this possibility was investigated on bagasse fibers. By means of the Weibull analysis, it was found that the thinner the bagasse fiber, the greater the strength. Fracture observation of bagasse fibers by scanning electron microscopy, indicated possible mechanisms related to this inverse correlation.
Arizona Salado turquoise: source studies with proton-induced X-ray emission and X-ray diffraction
Authors: Simon Arleyn W. , Crider Destiny L. , Murakami Tatsuya , Wilkens Barry
Published: January 2014

We compare the composition of turquoise source materials from Arizona to prehistoric blue-green stone artifacts recovered from Salado platform mounds (ca. AD 1275-1450) in the Tonto Basin of Central Arizona. Turquoise samples from known source areas in Arizona including Kingman, Castle Dome, in the Globe- Miami area are compare with others that may have been potential sources of turquoise artifacts recovered from the Salado platform mounds. The complementary techniques of proton-induced X-ray emission (PIXE) for chemical analysis and X-ray diffraction (XRD) for mineralogical signatures are used for nondestructive characterisation of both source area samples and archaeological artifacts. The results of the source area sample characterisations are compared quantitatively with the results of archaeological samples, which are evaluated in terms of their likelihood of being from each of the regional sources. The combination of mineralogical and chemical data to identify source materials provides a more thorough identification of the complex variations within turquoise related materials that may not be distinguished by visual inspection. The PIXE and XRD analysis are compared using a set of multivariate statistics including principal components analysis and discriminant analysis. Additionally, a set of Munsell colour charts specifically for the blue-green range of colours is used to objectively qualify colour in comparison to chemical and mineralogical signatures, as colour alone is not a reliable indicator of composition. The results provide objective data to assess directionality of procurement of turquoise and regional social and economic ties to better understand Salado regional connections during this dynamic period in the American Southwest.
Wine: looking ahead
Authors: Bordiga Matteo
Published: January 2014

Not available.
Analysis and integration of microarray data of Arabidopsis mutants
Authors: Zhou Daxiang , Liu Renhua , Xiong Shu
Published: January 2014

Zhou, D., Liu, R. and Xiong, S. 2014. Analysis and integration of microarray data of Arabidopsis mutants. Can. J. Plant Sci. 94: 235–243. Nowadays, high-throughput microarray data make it possible to study biological data on a large scale. It has successfully been applied to the gene function prediction in yeast, hypersensitive response in response to pathogen and human cancer. However, within the microarray data, there exists lots of unknown information which is worth mining. Based on mutants’ signature genes of Arabidopsis thaliana, we constructed a reference matrix including 267 pairs of subsets of differential reference profiles. We analyzed our data through expression profiles and connectivity map. Two notable results were detected by comparing every mutant in the matrix. Above all, the data mining procedure confirmed the biological relations not only between different stresses and glucose metabolism, but also stresses and MAPK signaling pathway among HSP90, PGM, VTE1, AXR4, SFR6, and SFR2 mutants. In addition, sfr6 might be involved in light cycle regulations, in accordance with the results of the overlap analysis.