bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Modeling of the Flow of Particle-Filled Resin through a Dual Scale Fibrous Media
Authors: Haji Hind , Saouab Abdelghani
Published: April 2015

We present numerical simulation of particle filled resin flow through a fibrous media taking into account dual scale porosity in LCM (Liquid Composite Molding) processes. During the flow, a strong interaction between the particle motion and the fluid flow takes place at the porous medium wall or at the fiber bundle surface. A model is developed to describe the particle retention and filtration in the porous media. In this study, the Stokes-Darcy equation is solved to describe the resin flow in a mesoscopic scale. The particle retention mechanism is extensively studied taking into account the influences from such parameters as size and concentration of particles. The particle filled resin flow through a fibrous media simulation is performed to demonstrate the effect on the retention and filtration mechanism during the composites manufacturing by LCM processes.
Experimental and Numerical Study of Interfacial Fracture Parameters of a Brazed Joints
Authors: Baazaoui A. , Fourcade T. , Dalverny Olivier , Alexis Joël , Karama Moussa
Published: April 2015

This paper deals with an identification methodology of the interfacial fracture parameters to predict the lifetime of a metallic brazed joint. The methodology is based on an experimental-numerical study whereby the optimal parameters are obtained. The experimental data, using the scanning electron microscope analysis, allowed approving that failure of the assembly based AuGe solder seems first to appear near the interfaces. These results were confirmed by micrographs analysis of the solder/insert and solder/substrate interfaces. Then, using shear test results and parametric identification coupled with a finite elements model (FEM) simulation, the damage constitutive law of the interfacial fracture based on a bilinear cohesive zone model are identified. The agreement between the numerical results and the experimental data shows the applicability of the cohesive zone model to fatigue crack growth analysis and life estimation of brazed joints.
Electrochemical Atomic Layer Deposition and Characterization of CdTe and PbTe Thin Films
Authors: Kabalan Amal , Singh Pritpal
Published: April 2015

This study reports the cycle chemistries involved in depositing CdTe and PbTe nanofilms. An automated thin-layer flow cell electrodeposition system was used to deposit the films at room temperature. Cyclic voltammetry was used to study the Underpotential Deposition (UPD) of the compounds. The monolayer/cycle deposition rate was also monitored in order to insure that the film is depositing at a uniform rate. The chemical composition of the films was characterized using Energy-Dispersive X-ray Spectroscopy (EDS) on a Scanning Electron Microscope (SEM). The crystallinity of the films was studied using a glancing angle X-ray diffractometer. The bandgaps of the films were calculated using measured optical reflection data.
Influence of the Ageing Temperature on the Selected Mechanical Properties of the Ti6Al7Nb Alloy
Authors: Dąbrowski Robert , Krawczyk Janusz , Rożniata Edyta
Published: April 2015

The results of investigations of the influence of the ageing temperature on the selected mechanical properties i.e. hardness, fracture toughness (examined by the linear elastic fracture mechanics - KIctest) and impact strength (KV) of two-phase Ti6Al7Nb alloy, are presented in the hereby paper. Investigations were performed in the ageing temperatures range: 450÷650°C of the alloy previously undercooled from the selected heating temperature (in two-phase range) - equal 970°C. The heating temperature was determined on the basis of the dilatometric curve of the alloy heating in the system ΔL = f ((T), where: ΔL – change of the sample length, T – temperature, which was then differentiated in the system: ΔL/ΔT = f (T). The dilatometer L78 R.I.T.A of the LINSEIS Company was used in the tests. Investigations of the alloy microstructure in the ageing temperatures range 450÷650°C were carried out by means of the light microscope Axiovert 200 MAT of the Carl Zeiss Company. It was found that nearly equiaxial grains of the primary α phase occur in the microstructure (of the volume fraction app. 30%) and that the volume fraction of the new lamellar α phase - formed from the supersaturated β phase - increases. With an increase of the alloy ageing temperature, in the mentioned above range, a small increase of its hardness from 305 to 324HV as well as a decrease of stress intensity factor KIcfrom 67.3 to 48.6 MPa x m1/2and impact strength (KV) from 40.2 to 31.3 J. The impact tests results were supplemented by the fractographic documentation. It was found, that the characteristic features of the fractures of impact test samples do not exhibit essential differences in dependence of the ageing temperature and material hardness. The fractographic investigations were performed by means of the scanning electron microscope NovaNanoSEM 450.
Research into the Aluminum-Zirconium Alloys Dedicated for Electirical Purposes
Authors: Piwowarska-Uliasz Marzena , Knych Tadeusz , Uliasz Piotr
Published: April 2015

The discussed subject matter concerns the influence of two kinds of Al-Zr alloy production technologies on the properties of the wires dedicated for electrical purposes. The paper presents research and the analysis of the research into the influence of the production technology and the processing technology on the ingot wires made from the heat resistant Al-Zr alloys as well as on the characteristics of the properties of the examined materials with the focus on the electrical and mechanical properties and their microstructure analysis. The materials subject to the mechanical and physicochemical research were materials manufactured in industrial and laboratory conditions in the form of the wire rod and cast bars as well as wires of various diameters drawn from them. The research concerned six Al-Zr alloys with the zirconium content from 0.05 to 0.32% of the mass.
Research in the Field of Manufacturing of Layered Brazing Materials
Authors: Kazana Wiesław , Ciura Ludwik , Karpiński Marcin
Published: April 2015

The results of research into manufacturing of layered brazing materials with silver brazing alloy BAg22 content and copper obtained in pressing at elevated temperature and rolling process for use in cutting tools working in harsh conditions were presented. Mechanical and dimensional properties of the constituent materials of the layered strips with 50 and 75% volume fraction of copper as the inner layer were selected, i.e. the BAg22 alloy strip and the copper strip, for the preliminary join operation in pressing process. Cladding process conditions of the set BAg22/Cu/BAg22 of the original thickness of 32mm for the ratio of layer thicknesses as 1:2:1 and 24mm of the original thickness for the ratio of layer thicknesses as 1:6:1 including the method of semi products surface preparation and range of forces and temperature parameters were specified. Plastic working conditions of pressed composite ingot in hot and cold rolling to the final thickness with the intermediate and final heat treatment parameters were developed.
Silver Based Brazing Composites for Trimetalic Components
Authors: Karpiński Marcin
Published: April 2015

The paper presents the aspects of trimets manufacturing related to raising quality and economic demands. The comparison of two types of alloys used as a filler metal has been performed. Modification of the chemical composition of brazing alloy, currently used for trimet composite strips in terms of lower silver contents has been proposed. The joining of conventional cemented carbides with steel has been investigated.
Effect of Alloying Elements on Mechanical Properties of Al-Si-Cu-Mg Cast Alloys
Authors: Pan Yan Peng , Zhang Zhi Feng , Li Bao , Yang Bi Cheng , Xu Jun
Published: April 2015

To develop Al-Si cast alloys with high performance is important for lightweighting vehicles. In this study, the effects of the alloying elements such as Si, Cu, Mg contents (5%-7% Si, 1%-3%Cu, 0.3%-0.9%Mg) on mechanical properties of a test Al-Si-Cu-Mg cast alloy was studied to achieve a specific composition. The experimental results show that the Al-6%Si-3%Cu-0.3%Mg alloy has better comprehensive mechanical properties after T6 heat treatment, which indicates a remarkable interaction of the alloying elements for improving performance.
Influence of Air Heat Treatment on Bonding Strength and Microstructure of Al2O3-13wt%TiO2/NiCrAl Coating
Authors: Wang Guo Wei , Zhou Ze Hua , Wang Ze Hua , Liu Han , Shao Jia , Yi Yu , Zhang Xin
Published: April 2015

Owing to typical weaknesses of Al2O3-13wt%TiO2/NiCrAl coating (AT13), appropriate air heat treatment is an effective method in improving the bonding strength and microstructure of AT13. AT13 was air heat-treated with varying holding times and cooling methods. The aims are not only to ascertain the changes of the bonding strength and micro-structure of AT13 under various conditions, but also to understand the influence of holding time and cooling method on the bonding strength and microstructure of the coating. The experimental results showed that the best bonding strength and lowest porosity of AT13 were obtained using proper heat treatment of heating up to 560°C for 6 h along with two-step cooling. The two-step cooling is better than normal furnace cooling in improving properties of the coating, which is attributed to the densification of AT13 and release of residual stress.
Study on the Lubricating Performance of Nano-TiO2 in Water-Based Cold Rolling Fluid
Authors: Sun Jian Lin , Zhu Zuo Xin , Xu Peng Fei
Published: April 2015

A type of water-based cold rolling fluid has been developed by adding TiO2 nanoparticles. The tribological behavior of nanoTiO2 water-based rolling fluid was investigated by using four-ball machine. The worn surfaces of the steel balls were analyzed by using OLYMPUS laser confocal microscopy. Results indicate that nanoTiO2 nanoparticles significantly improved the anti-wear properties in the way of micro-ball bearing and perfecting the tribological behavior of water-based rolling fluid. The cold rolling experiment shows that the nanoTiO2 water-based rolling fluid had a good rolling lubricant performance under the condition of concentration of 0.7wt.% for the upper limit. The nanoTiO2 water-based rolling fluid can not only decrease the minimum rolling gauge and the surface roughness of the work piece, but also prevent direct contact between roller and work piece which could lead to the rolled surface scratches and adhesion defects.
Influence of Fly Ash on Magnesium Oxychloride Cement Deformation
Authors: Dong Jin Mei , Yu Hong Fa , Wang Mei Juan
Published: April 2015

The inhibition effect of fly ash on the deformation of magnesium oxychloride cement is not obvious. With the increase of fly ash, the deformation of magnesium oxychloride cement decreased at first, and then increased. The smallest deformation is the proportion of FA-35. The fly ash can promote the formation of the 5·1·8 phase crystal and slow the speed of 5·1·8 phase changing into Mg (OH)2. The growing crystals were disordered, like the scattered tree branches. The causes of FA-35 specimen expansion deformation can be explained by the configuration of the crystal.
Research on a New Type of Martensite Stainless Steel Electrode Used for Hardfacing
Authors: Yang Kè , Yang Ke , Xu Hong Xiang , Bao Ye Feng
Published: April 2015

A new type of martensite stainless steel deposit electrodes was developed. The welding technicality of the electrodes was analyzed, and the wear resistance of the deposited metal was studied through a slurry abrasive wear test. The results indicated that the welding arc of the electrodes could keep steady during welding process, and the appearance of weld and the detachability were satisfied. The microstructure of the hardfacing alloy consisted of lath martensite and fine strengthening phase with dispersive distribution. The mass loss of hardfacing alloy was about one third of that of substrate, which means the hardfacing alloy has a good wear resistance property. And the main wear mechanisms are micro-cutting, micro-ploughing and the second wear of plastic deformed metals.
High-Strain-Rate Response of a Specially-Made Copper Sample
Authors: Liu Dong Mei , Wang Qiang Song , Xie Guo Liang , Xie Wei Bin , Li Yang , Gao Xue Cheng
Published: April 2015

In the present study, a systematic study on both the high strain-rate tensile and compressive deformation behaviors of a specially-made copper sample have been carried out at different high temperatures, by using the split Hopkinson bar experiments. The Johnson-Cook constitutive model was used to model the high strain-rate responses of the specimen at high temperatures. The results showed that compared with other metallic materials, the specially-made copper sample had a relatively stronger strain-rate-hardening effect and weaker temperature-softening effect. Evolution of the microstructure suggests that under high strain-rate, both the dislocation slip and deformation twins contribute to the plastic strengthening of the copper specimen, resulting in the strain-rate-hardening effect. And the dynamic recrystallization behavior plays an important role during the high strain-rate deformation process at the high temperatures.
Solidification Structure of 6063 Alloy under Pulsed Magnetic Field
Authors: Liu Shi Chao , Chen Hang , Zhang Jun Jia , Wang Peng Fei , Jie Jin Chuan , Li Ting Ju
Published: April 2015

The influences of pulsed magnetic field (PMF) on solidification structure of 6063 alloy were studied in this article. The results show that solidification structure of 6063 alloy can be refined with the application of PMF. The dendrite growth restrained and the macrostructure changed from large dendrite grains to fine equiaxed grains. The grain size decreased when the voltage increased from 0V to 600V. However, when the pulse frequency increased from 5Hz to 15Hz, the average grain size decreased continuously until reached a limit, and then the grains coarsened with further increase of the pulse frequency. The vibration caused by PMF not only made the temperature field of the melt uniform ,but also brook off the initial solidified grains formed on the cold wall of the mold, and spurs the grains to move to the center of melt which can be acted as nuclei.
Development of Hot Rolled Strips for Internal Plates of Automobile
Authors: Peng Xing Dong , Wang Mei Ling , Li Sheng Li , Xu Jie
Published: April 2015

The hot rolled strips for internal plates of automobile was developed by taking the technologies of low-carbon softening steel, including strictly control the chemical composition content during the steel melting and optimization of the rolling processes in the thin slab continuous casting and rolling line. The results showed that when carbon content was 0.04%, adding aluminum content or reducing silicon content and manganese content, reducing the reduction in previous rolling passes and increasing the reduction of the finishing pass at high temperature was beneficial for reducing the yield strength and tensile strength of the hot rolled strips. The precipitate of the samples after annealing showed that the precipitate of aluminum-nitride increased significantly at 850°C. And the texture of the samples after annealing showed that the main texture was {110} <001> and its intensity was 1.7-2.0, annealing with hot rolled strips did not benefit the advantageous texture. Tension-tension fatigue properties of hot rolled strips and cold rolled ones were determined, the results showed that the fatigue properties of hot rolling strips were rather higher than that of cold rolled ones. In the stamping experiments of some automobile parts, there was not any drawback, and the forming properties of hot rolling strips were equal to that of cold rolled ones. It was feasible to replace the cold rolled strips with the hot rolled ones for the internal plates of automobile.
Microstructure and High-Temperature Oxidation of Ni-Si3N4 Composite Coatings by Pulse Electrodeposition
Authors: Zhao Kun , Sun Wan Chang , Miao Chun Yu , Cai Hui , Zhang Ju Mei , Niu Li Bin
Published: April 2015

Nickel matrix and Si3N4 micron particles were co-deposited on the aluminum alloy by pulse electro-deposition for high temperature performance. Meanwhile, the oxidation resistance was evaluated through the high temperature oxidation test. The phase structure, micrographs and components of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS) respectively. The results indicated that Si3N4 particles were uniformly distributed across the coating and there were no pores and cracks or other defects at the coating/substrate interface. Ni-Si3N4 composite coatings are characterized by pyramidal micro-crystallite structure. The thickness of Ni-Si3N4 composite coatings were up to 80 μm for 2h. The results also revealed that the Ni-Si3N4 composite coatings presented better oxidation resistance than the pure Ni coating and aluminum alloy at high temperature. After oxidation at 673 K for 8h, the oxidation resistance of Ni-Si3N4 composite coatings presented the improved oxidation resistance behavior compared to pure Ni and the aluminum alloy, respectively.
Modeling and Simulation of Influence of Solidification Velocity on the Structure of Porous Copper and Aluminum
Authors: Yang Qian Qian , Liu Yuan , Li Yan Xiang
Published: April 2015

In this article, a three-dimensional time-dependent model describing the evolution of single pore during the solid/gas eutectic unidirectional solidification process (also calledgasarprocess) was established. The mass transfer, bubble nucleation, pore growth and interruption were all considered in this model. The pore structure of lotus-type porous copper and aluminum were simulated under different solidification velocities. The results indicate that: coupled growth of both solid and gas phases can be achieved in a proper range of solidification velocities. The solidification velocity for Cu-H2system is dozens of that for Al-H2system when the pore diameter is similar to each other. The differences of the solute distribution coefficient (k0), diffusion coefficient (DL) and the constant of solubility of hydrogen (ξ(Tm)) in the melt are regarded as the main reasons of the big discrepancy of solidification velocity between Cu-H2and Al-H2systems.
Microstructure and Mechanical Properties of TRIP-Aided Steels with Different Heat Treatments
Authors: Dong Rui , Zhao Ai Min , Ding Ran , He Jian Guo , Hu Han Jiang
Published: April 2015

The microstructures, mechanical properties and retained austenite characteristics of TRIP-aided steels with three different heat treatments were studied in this paper. The results indicated that the designed annealing treatments resulted in completely different matrices and the morphologies of second phase, and a significant difference in mechanical properties. The TAM steel was found to have fine annealed martensite lath matrix and inter lath acicular retained austenite, and possessed an excellent combination of strength and elongation which attributed to the highest retained austenite volume fraction and carbon concentration. For TPF steel, the higher instability and lower carbon content of retained austenite and the soft matrix resulted in the lowest ultimate tensile strength and total elongation. While in TBF steel, the stability of retained austenite was lower than that in TAM steel but higher than that in TPF steel. The ultimate tensile strength of TBF was significantly higher than the TAM and TPF steels, but the ductility of TBF steel was lower than TAM steel.
Heat Treatment of 10Cr12Ni3Mo2VN Blade Steel for Ultra Supercritical Unit
Authors: Li Jun Ru , Gong Chen , Zhou Le Yu , Chen Lie , Zuo Hui , Liu Ya Zheng
Published: April 2015

In this work, the effects of final heat treatment including quenching and tempering process on mechanical properties of 10Cr12Ni3Mo2VN steel were investigated by orthogonal experimental. It is shown that, the quenching process had a small effect on the strength properties. But the impact property obviously decreased with the increase of quenching temperature, that is due to the grain coarsening. It can be found that tempering temperature is the major factor which affects the mechanical properties. Tempering process had a large effect on the precipitation of carbides and that affected the strength, toughness and plastic greatly. The impact toughness had a minimum after tempered at 650°C between 600°C~700°C. The experimental results show that the M23C6 type carbides precipitated at the grain and martensite lath boundary were the main reason which decreased the impact toughness when tempering temperature increased from 600°C to 650°C.
Effects of Heat Treatment on Mechanical Properties of Ni-P-CNT Composite Coating
Authors: Shi Qin , Sun Wan Chang , Gao Jun , Wang Ying , Tian Miao Miao
Published: April 2015

Ni-P-CNT nanocomposite coating was successfully co-deposited by electroless plating and the heat treatment was carried out at 200°C, 400°C, 600°C in nitrogen atmosphere respectively for a holding period of 1 h. The effects of heat treatment on the microstructure and mechanical properties of Ni-P-CNT composite coating were investigated. The results indicate that the heat treatment at 400°C can greatly improve the hardness and wear resistance of the composite coating. The reason is that Ni3P hard phase is greatly precipitated after the heat treatment, which played a strengthening effect. On the other hand, the precipitated Ni, Ni3P crystalline phases in the coating result in an increase of the amount of grain boundary. The increased amount of grain boundary broke the spread of shear force during friction process, and reduced the wear loss caused by friction pair. Compared with as-deposited coating, the coatings after heat treatment possess higher microhardness and wear resistance.
Wear Resistance of Cu10Al5Fe5Ni Alloy
Authors: Zou Jun Tao , Wang Chan , Li Yang , Wang Xian Hui , Liang Shu Hua
Published: April 2015

The effect of ambient temperature, materials state and lubrication condition on wear resistance of Cu10Al5Fe5Ni alloy was investigated. The wear surface morphology was characterized by a scanning electron microscope (SEM), and the wear mechanism was discussed as well. The results show that the friction coefficient of Cu10Al5Fe5Ni alloy increases and then decreases with increasing temperature. The wear rate of the Cu10Al5Fe5Ni alloy after solid solution and ageing treatment is less than that of the as-cast alloy, and the wear rate of Cu10Al5Fe5Ni alloy reduces dramatically from 5.31×10-5 mm3 / (m· N) into 1.80×10-6 mm3 / (m·N) after adding lubricating oil. At elevated temperature, the prior wear mechanism is the fatigue wear, accompanying by slight abrasive wear and adhesive wear for the aged Cu10Al5Fe5Ni alloy.
Effect of Container on the Microstructure and Properties of Powder Metallurgy TiAl Alloys
Authors: Wu Jie , Xu Lei , Lu Zheng Guan , Guo Rui Peng , Cui Yu You , Yang Rui
Published: April 2015

Pre-alloyed powder of Ti-47Al-2Cr-2Nb-0.15B was prepared by a gas atomization process and powder metallurgy (PM) γ-TiAl alloys were made through a hot isostatic pressed (HIPed) route. The atomized powders were canned in containers, degassed, sealed, and HIPed. Effect of two different canning materials (mild steel and commercial pure titanium (CP-Ti)) on the microstructure and properties of as-HIPed γ-TiAl alloy were discussed. Due to the reaction between mild steel containers and γ-TiAl at relative high temperature (over 1230 °C), the γ-TiAl matrix is contaminated. CP-Ti canned γ-TiAl showed bigger yield and fracture strength than mild steel canned TiAl. PM γ-TiAl alloy parts having complex shape could be manufactured by the near net-shape process.
Finite Element Analysis of Removable Shape Memory Alloy Pipe Joint’s Cone Sealing Performance
Authors: Zhou Bin , Liu Fu Shun
Published: April 2015

According to the behavior of shape memory alloys, a structure of removable shape memory alloy pipe joint was designed. The contact manner of two parts of this structure is cone-globe. Cone-globe sealing is the key point of this structure’s sealing. Therefore the finite element analysis software ANSYS was used to simulate and calculate the sealing. The result shows that the width of the sealing surface and the contact stress altered with the change of structural parameters, which affected the sealing most. According to the value of the sealing surface’s width and the contact stress, the structural parameters including cone angle can be definitely settled.
Application of Artificial Neural Networks to Optimize Processing - Properties of Ni-Tic Composite Coatings
Authors: Wei Han Jun , Sun Wan Chang , Hou Guan Qun , Zhang Feng , Shi Qin
Published: April 2015

The plating parameters for optimizing the wear and corrosion resistance of Ni-TiC composite coatings were selected by orthogonal test, mainly including the TiC particles concentration, current density, duty cycle, frequency and stirring rate. A three-layer BP (Back Propagation) neural network with Lavenberg-Marquardt algorithm was established by MATLAB, which was used to train the network and predicted orthogonal experimental data. In addition, the best parameters combination of the composite coating were predicted and verified by experiments. The results predicted through the proposed BP model are in good agreement with the experimental values, the relative error is small, and the maximum error is less than 3% and the coefficient of determination value is 0.9997.
Simulating Structural Transformation of a Cu1553 Nanoparticle on Heating at Atomic Scale
Authors: Zhang Jing , Yu Peng
Published: April 2015

By means of molecular dynamics simulations within the framework of embedded atom method, we observe the structural transformation of a Cu nanoparticle containing 1553 atoms at atomic scale on a heating series from 350K to 1200K at an increment of 50K. With increasing the temperature, the structural changes result in apparent increases in internal energy. Pair distribution functions (PDFs) and pair analysis (PA) technique as well as the atom packing at different temperatures are used to identify the local structural patterns during the melting of this particle.
Influence of Carbon Nanotube Aspect Ratio on Glass Transition Temperature of Polymers: A Molecular Dynamics Simulation Study
Authors: Jiang Cai , Zhang Jian Wei , Lin Shao Feng , Ju Su , Jiang Da Zhi
Published: April 2015

Molecular dynamics (MD) simulations on three single walled carbon nanotube (SWCNT) reinforced epoxy resin composites were conducted to study the influence of SWCNT type on the glass transition temperature (Tg) of the composites. The composite matrix is cross-linked epoxy resin based on the epoxy monomers bisphenol A diglycidyl ether (DGEBA) cured by diaminodiphenylmethane (DDM). MD simulations of NPT (constant number of particles, constant pressure and constant temperature) dynamics were carried out to obtain density as a function of temperature for each composite system. The Tg was determined as the temperature corresponding to the discontinuity of plot slopes of the densityvsthe temperature. In order to understand the motion of polymer chain segments above and below the Tg, various energy components and the MSD at various temperatures of the composites were investigated and their roles played in the glass transition process were analyzed. The results show that the Tg of the composites increases with increasing aspect ratio of the embedded SWCNT
Computer Simulation of the Early Stage of Precipitation of L12-Ni3(Al,V) Using Microscopic Phase Field Method
Authors: Dong Wei Ping , Chen Zheng
Published: April 2015

Based on the phase field theory, the long-range order (LRO) parameter related interatomic potentials equations were utilized to calculate the interatomic potentials of L10-Ni3(Al,V), L12-Ni3Al and L12-Ni3(Al,V) phases varying with temperature and concentrations. Using these potentials, the simulated microstructure evolution and the order parameter with the time of Ni75Al20V5 ternary alloy are simulated at temperature 1000K during the early stage of the precipitation process in this research. Results testify that the precipitation sequence during the early stage of Ni75Al20V5 alloy is the disordered phase →L10 pre-precipitation phase →L12 equilibrium phase. Firstly, the nonstoichiometric L10 pre-precipitation phase formed by congruent ordering precipitation mechanism; secondly, the nonstoichiometric L12 phase formed by transforming from L10 phase; thirdly, the stoichiometric equilibrium L12 phase formed by spinodal decomposition precipitation mechanism. It is discovered that the precipitation mechanism (congruent ordering+ spinodal decomposition) process was closely related to free energy and interatomic potentials: L10 pre-precipitation phase’s free energies are higher and interatomic potentials are smaller than those of L12 equilibrium phase.
Elastic Properties and Electronic Structures of L12-TiAl3 and L12-Ti(Al,Pt)3: A Density Functional Theory Investigation
Authors: Huang Bo , Duan Yong Hua , Yong Sun , Peng Ming Jun
Published: April 2015

First-principles calculations have been carried out to investigate the elastic properties and electronic structures of L12-TiAl3and L12-Ti (Al, Pt)3. The optimized structural parameters were largely consistent with the experimental values. The electronic density of states (DOS) and the differences of charge density distribution were given. The independent single-crystal elastic constants and polycrystalline elastic parameters such as bulk modulusB, Young’s modulusE, shear modulusG, Poisson’s ratioνand anisotropy valueAhave been calculated by Voigt-Reuss-Hill averaging scheme. The results indicate that the L12-Ti (Al, Pt)3exhibits larger anisotropy and more ductile than L12-TiAl3.
Effect of Double Shot Peening on Room-Temperature Notched Fatigue Property of TC4 Titanium Alloy
Authors: Wang Xin , Li Si Qing , Yang Qing , Teng Bai Qiu , Li Zhen Xi , Meng Zhen Wei , Zhao Zhen Ye
Published: April 2015

Single shot peening (SSP) with cast-iron shot and double shot peening (DSP) with cast-iron shot and ceramic shot were applied to investigate the relationship between surface integrity status and the fatigue property of titanium alloy TC4 on the notched specimens (stress concentration coefficient Kt=1.7). Surface roughness, residual stress profile and fatigue curve of the notched specimens were tested using scanning profilometer, XRD residual stress tester and rotating-bending fatigue testing machine, respectively. The results showed that surface roughness decreased 18.3% from Ra 1.09 μm post SSP to Ra 0.89 μm after DSP. Moreover, the position of the maximum value of residual stress migrated out close to the surface and the value of surface residual stress raised 12.6% to-800MPa from SSP. Additionally, the fatigue limit of the notched specimens pose SSP increased 64.7% to 467MPa from 283 MPa of AM, furthermore, edged up by 8% from 432MPa on unpeened smooth samples. It may be concluded that the double shot peening on titanium alloy has, therefore, eliminated the weakness of fatigue property caused by stress concentration.
Low Energy versus Pulse in MIG Welding of “Thin” Sheets of Aluminium Alloy EN AW 6082
Authors: Adamiec Janusz , Rykała Janusz
Published: April 2015

The article presents the course and the results of research on comparison of material and technological welding conditions of EN AW 6082 aluminium alloy using low energy (CMT) and pulsed current (MIG-Pulse) welding methods, as well as discusses the properties of welded joints and the application fields of modern low energy welding devices for joining thin aluminium sheets.
Structure and Functional Properties of Surface Layer Produced on Cast Aluminium Light Alloys by Appliance of Anodisation
Authors: Konieczny Jarosław , Labisz Krzysztof , Dolata Anna Janina
Published: April 2015

The aim of the work is presents the influence of casting method and anodic treatment parameters on properties, thickness and structure of an anodic layer formed on aluminium casting alloys. Investigations were carried out on the laser profile measurement gauge MicroProf from company FRT, abrasive wear test was made with using ABR-8251 equipment delivered by TCD Teknologi ApS and microstructure investigations were made with using a light microscope equipped with an electronic camera configured with a computer on two casting aluminium alloys which both were founding by pressure die casting and gravity casting. The researches included analyse of the influence of chemical composition, geometry, roughness and abrasive wear resistant of anodic layer obtained on aluminium casts.Research limitations/implications Contributes to research on anodic layer for aluminium casting alloys. Practical implications Conducted investigations lay out the areas of later researches, especially in the direction of the possible, next optimization anodisation process of aluminium casting alloys, e.g. in the range of raising resistance on corrosion. Originality of this research was to describe the range of possible applications increases for example as materials on working building constructions, elements in electronics and construction parts in air and motorization industry in the aggressive environment.
Erosion processes in black marl soils at the millimetre scale: preliminary insights from an analogous model
Authors: Bechet J. , Duc J. , Jaboyedoff M. , Loye A. , Mathys N.
Published: April 2015

Abstract. To investigate the millimetre-scale surface processes caused by natural rainfall, an undisturbed sample of badlands soil (1 m long, 0.5 m wide and 0.15 m thick) was carefully extracted. The sample is composed of black marl soil from a badlands area of the Draix Observatory (SE France). After extraction, the undisturbed sample was placed at the same slope angle (45°) as its original orientation and was then monitored for several processes via a terrestrial laser scanner (TLS) with millimetre-scale accuracy and resolution. This experiment identified several surface processes interpreted as micro-landslides, swelling of the black marl material and lateral expansion that closed desiccation cracks. These micro-processes illustrate the complexity of the surface micro-topography changes that control erosion and infiltration rates over time.
Group decision-making approach for flood vulnerability identification using the fuzzy VIKOR method
Authors: Lee G. , Jun K. S. , Chung E.-S.
Published: April 2015

Abstract. This study proposes an improved group decision making (GDM) framework that combines the VIKOR method with data fuzzification to quantify the spatial flood vulnerability including multiple criteria. In general, GDM method is an effective tool for formulating a compromise solution that involves various decision makers since various stakeholders may have different perspectives on their flood risk/vulnerability management responses. The GDM approach is designed to achieve consensus building that reflects the viewpoints of each participant. The fuzzy VIKOR method was developed to solve multi-criteria decision making (MCDM) problems with conflicting and noncommensurable criteria. This comprising method can be used to obtain a nearly ideal solution according to all established criteria. This approach effectively can propose some compromising decisions by combining the GDM method and fuzzy VIKOR method. The spatial flood vulnerability of the southern Han River using the GDM approach combined with the fuzzy VIKOR method was compared with the spatial flood vulnerability using general MCDM methods, such as the fuzzy TOPSIS and classical GDM methods (i.e., Borda, Condorcet, and Copeland). As a result, the proposed fuzzy GDM approach can reduce the uncertainty in the data confidence and weight derivation techniques. Thus, the combination of the GDM approach with the fuzzy VIKOR method can provide robust prioritization because it actively reflects the opinions of various groups and considers uncertainty in the input data.
Alpha-1 Antitrypsin and Monocytes
Authors: Serapinas Danielius
Published: April 2015

Alpha-1 antitrypsin (AAT) is the main circulating serine proteinase inhibitor. A number of studies suggest that AAT can also exhibit biological activity independent of inhibition of serine proteases. The aim of the study was to make experimental investigation of AAT influence on monocytes stimulated by bacterial endotoxyn . AAT affects monocyte responses to LPS by regulating soluble CD14 release. Here we show that a short-term monocyte exposure to AAT leads to an increase of CD14 levels (p0.05). In parallel, a short-term cell exposure to AAT significantly enhances TNFα release. However, AAT was found to have a dual effect on LPS-induced TNFα release. Probably a rapid increase in AAT concentrations during various inflammatory and infectious conditions may enhance the magnitude of monocyte responses to endotoxin and subsequently accelerate resolution of the inflammatory reaction.
Differencial Diagnosis of Hypovolemia and Cushing‘s Response in Traumatic Brain Injury Patients, Using Hemodynamic Assessment Methods, to Prevent Secondary Brain Damage
Authors: Zinkevičiūtė Žarskienė Giedrė , Bilskienė Diana , Macas Andrius
Published: April 2015

Traumatic brain injury is the leading cause of death and further cause of disability and a major public health problem. Although the severity of the injury depends directly on the primary brain injury, secondary brain injury deteriorates the outcomes. The main causes of secondary ischemic injury include hypotension (systolic blood pressure 90mmHg) and hypoxaemia (PaO260mmHg), which are directly associated with increase of morbidity and mortality due to severe traumatic brain injury. Hypoxia and hypotension during decompresive craniotomy are independently associated with significant increaeses in vegetative state development and higher frequency of disability. Intraoperative period, including immediate anaesthesia during urgent craniotomy, is a critical moment for these patients. Their intraoperative hypotension can be caused by various factors, such as blood loss due other traumatic injuries, direct pulmonary or heart disorders, sympathetic tone lesions (spinal cord injury and neurogenic shock), potent anesthetic medicaments action or current hypovolemia and inadequate infusion therapy. How to solve this situation? Usually we choose a larger infusion therapy and vasoactive drugs. Is it realy a best solution for the patient? Severe brain trauma and related complications are the most common morbidity and mortality causes in young and middle-aged people. The initial injury we can not influence, but to avoid the major secondary brain injury risks, especially such as hypotension and hypoxia, are required. Only quick and accurate diagnosis, secondary risk factors prevention and immediate treatment may improve the outcomes.
What Obeah Does Do:
Authors: Crosson J. Brent
Published: April 2015

Obeah, which colonial ordinances defined capaciously as “any assumption of supernatural power,” was a crime in Trinidad until 2000, and the law continues to make Obeah a punishable offense in most of the anglophone Caribbean. Scholars have noted that contemporary attitudes toward Obeah—a hard-to-define term—are largely negative, implying spiritual harm. My fieldwork in a region of Trinidad regarded as the island's capital of Obeah, however, revealed polyvalent, context-contingent attitudes toward the term. Using ethnographic examples, I offer alternatives to scholarly approaches that have explained away Obeah's harm as evidence of colonial false consciousness. My interlocutors took shifting, even contradictory stances toward Obeah that depended on tactical contexts of power. By examining attempts to intervene in the justice system through spiritual force, I argue that Obeah is a justice-making technology and that, like all systems of law, the potential for harm is part of its power. In the final part of the paper, I argue that rather than conforming to a definition of religions as mutually exclusive confessional communities rooted in collective avowals of belief, Obeah models a counterdiscourse on social relations that I call “altered solidarities,” challenging regnant conceptions of religion as the basis for legal recognition in modern states.
La segregación vertical y horizontal en las agencias de publicidad antes y después de la ley de igualdad de mujeres y hombres
Authors: Martín-Llaguno Marta , Navarro-Beltrá Marián
Published: April 2015

La erradicación de las desigualdades de género ha originado en España un marco jurídico cuyo impacto apenas ha sido evaluado. En concreto, los efectos netos sobre los medios de comunicación son una incógnita.

Este trabajo valora la evolución de la segregación vertical y horizontal en las agencias de publicidad como indicador indirecto de la repercusión de la Ley Orgánica para la Igualdad Efectiva de Mujeres y Hombres. Los resultados de dos estudios transversales con cuestionarios autocompletados (por 563 empleados en 2004 y por 309 en 2010) apuntan que mientras la segregación vertical se habría aminorado, la horizontal habría aumentado. El origen de la evolución puede ser multicausal pero el marco normativo de la última década puede haber contribuido al cambio.
Economic Evaluations of Organ Transplantations - A Systematic Literature Review
Authors: Jarl Johan , Gerdtham Ulf-G.
Published: April 2015

The purpose of this study is threefold; 1) to establish the current level of knowledge regarding cost-effectiveness of organ transplantation, 2) to identify knowledge gaps, and 3) to suggest a framework for future studies. A systematic literature review of economic evaluations of transplantations of solid organs was conducted in October 2010. Economic evaluations published since 2000 and reviews published since 1987 for kidney, liver, lung, heart, pancreas, and small bowel transplantations were collected. The studies were analysed regarding results and study characteristics. The review demonstrates a lack of economic evaluations for all included organ transplantations. The cost-effectiveness of kidney transplantation, and to some extent liver transplantation, compared to a non-transplant alternative appears to be established. However, cost-effectiveness for transplantation of lung, heart, pancreas, and small bowel can neither be established nor rejected based on earlier studies. Many of the included studies were limited in a number of ways; e.g. using short follow-up period, failing to account for sample selection in treatment groups, comparing to unrealistic alternatives, lacking important cost categories, and using a limiting perspective. Recommendation for future studies are, besides accounting for the above, to conduct sub-group analyses as patient and disease characteristics, among other things, has been shown to affect the cost-effectiveness of organ transplantation.  Link to Appendix
Diet, risk of obesity and socioeconomic circumstances of individuals in the UK: A seemingly unrelated approach
Authors: Olajide Damilola , Ludbrook Anne
Published: April 2015

Understanding the link between diet, risk of obesity and the underlying socioeconomic circumstances of the individual is useful for health promotion and improvement interventions. In this study, we examined the socioeconomic factors that jointly affect food consumption choices and risk of obesity. We analyse the National Dietary and Nutrition Survey (2000/01) of adults aged 19-64 years living in private households in the UK, using a health production framework. We used information on the complete food history on individuals in the previous week to create eight common food groups. We estimated a system of linear risk of obesity (as measured by Body Mass Index) and eight diet equations with error terms that are correlated across equations for a given individual, but are uncorrelated across individuals, using the seemingly unrelated regression method. Our findings indicate that the socioeconomic factors (e.g. income and education) associated with sources of healthy eating differ. While increasing household purchasing power may be more effective for increasing consumption of healthier foods such as fruit and vegetables, more knowledge and information about healthy eating may be more effective for cutting down on consumption of less healthy foods (e.g. preserves and savoury foods). An understanding of these different healthy eating contexts is essential for the development of effective targeted food based policies aimed at reducing the risk of obesity. Link to Appendix
Obesity and Surgical Treatment – A Cost-Effectiveness Assessment for Sweden
Authors: Borg Sixten , Näslund Ingmar , Persson Ulf , Ödegaard Knut
Published: April 2015

Background:The rising trend in the prevalence of obesity has during the past decades become a major public health concern in many countries, as obesity may lead to comorbidities and death. A frequent used marker for obesity is the Body Mass Index (BMI). The cost of treatment for obesity related diseases has become a heavy burden on national health care budget in many countries. While diet and exercise are the cornerstones of weight management, pharmaco­therapy is often needed to achieve and maintain desired weight loss.  In some cases of extreme obesity, bariatric surgery may be recommended. It is expected to increase by 50% in Sweden.Objective: The overall objective was to develop a cost-effectiveness model using the best available evidence to assess the cost-effectiveness of gastric bypass (GBP) surgical treatments for obesity in adult patients, in comparison with conventional treatment (CT), in Sweden from a healthcare perspective. With the model we also seeked to identify the lower cut-off point using BMI criteria, for the surgical intervention to be cost-effective. Methods:A micro-simulation model with an underlying Markov methodology was developed, that simulates individual patients. It simulates the outcomes of the patients in terms of treatment costs, life years, and quality adjusted life years (QALY) over his/her remaining lifetime. The costs are presented in SEK in the year 2006 price level (1 SEK ≈ 0.11 EUR ≈ 0.14 USD).Results: We estimated that the incremental cost per QALY gained will not exceed SEK 33,000 per QALY in patients with BMI < 35. In patients with BMI > 35 kg/m2, gastric bypass surgery has lower costs compared to conventional treatment. Conclusion: Gastric bypass surgery is a cost-effective intervention compared to conventional treatment consisting of watchful waiting, diet and exercise.
Why a positive link between increasing age and income-related health inequality?
Authors: Nordin Martin , Gerdtham Ulf G
Published: April 2015

This study analyze why the SES-health gradient increases with ageing. We use Statistics Sweden’s Survey of Living Conditions (the ULF). By comparing various SES and health outcome relationships we explore the age increase in health inequality and distinguish between three types of explanations, namely: i) age increase in the causal SES effect; ii) reversed health effect on SES, and iii) lifecycle variation in the measurement errors in SES. Thus, the study indicates that the age increase in health inequality is primarily caused by a reversed causality going from health to annual income, and the probable mechanism is health affecting the labour supply of the individual. The evidence in our study is not conclusive in that we can prove anything, but all the documented evidence supports this conclusion.