bluuebunny/crossref_metadata_2025 huggingface dataset:
Presence of CP4-EPSPS Component in Roundup Ready Soybean-Derived Food Products
Authors: Wu Honghong , Zhang Yu , Zhu Changqing , Xiao Xiao , Zhou Xinghu , Xu Sheng , Shen Wenbiao , Huang Ming
Published: February 2012

With the widespread use of Roundup Ready soya (event 40-3-2) (RRS), the traceability of transgenic components, especially protein residues, in different soya-related foodstuffs has become an important issue. In this report, transgenic components in commercial soya (including RRS) protein concentrates were firstly detected by using polymerase chain reaction (PCR) and western blot. The results illustrated the different degradation patterns of the cp4-epsps gene and corresponding protein in RRS-derived protein concentrates. Furthermore, western blot was applied to investigate the single factor of food processing and the matrix on the disintegration of CP4-EPSPS protein in RRS powder and soya-derived foodstuffs, and trace the degradation patterns during the food production chain. Our results suggested that the exogenous full length of CP4-EPSPS protein in RRS powder was distinctively sensitive to various heat treatments, including heat, microwave and autoclave (especially), and only one degradation fragment (23.4 kD) of CP4-EPSPS protein was apparently observed when autoclaving was applied. By tracing the protein degradation during RRS-related products, including tofu, tou-kan, and bean curd sheets, however, four degradation fragments (42.9, 38.2, 32.2 and 23.4 kD) were displayed, suggesting that both boiling and bittern adding procedures might have extensive effects on CP4-EPSPS protein degradation. Our results thus confirmed that the distinctive residues of the CP4-EPSPS component could be traced in RRS-related foodstuffs.
GPR investigation in different archaeological sites in Tuscany (Italy). Analysis and comparison of the obtained results
Authors: Piro S. , Campana S.
Published: February 2012

A Ground‐penetrating Radar (GPR) survey can enhance the quantity and quality of information when applied to archaeological prospection. The potential of the GPR method lies both in its relevance to a wide range of site conditions and the complementary nature of the data in comparison with other geophysical methods.

The areas described in this paper were ‘detected’ by the Laboratory for Landscape Archaeology and Remote Sensing of University of Siena, during aerial prospection between 2001–2005. Analysis of the aerial photographs allowed interpretation of the Aiali, Castellina and Pava sites, province of Grosseto and Siena (Tuscany, Central Italy). These sites are related to quite a limited chronological range between late Roman and the early mediaeval period.

All sites were studied through a multimethodological project based on the integration of field‐walking and digital global position system (DGPS) surveys combined with different geophysical investigations such as: differential magnetics, ground penetrating radar (GPR) and automatic resistivity profiler (ARP).

This paper demonstrates the effectiveness of GPR over the indicated sites characterized by differences in the soil condition and hypothesized archaeological features. With this method a high‐resolution data acquisition was adopted with the aim of reconstructing the location, depth and shape of the archaeological structures in the selected areas. Signal processing and the time‐slice representation technique were used for the analysis of the collected data.

Archaeological excavations and interpretations were then conducted systematically after completing the geophysical surveys (from 2006–2009), which confirmed the location and shape of most of the individualized structures. The obtained results demonstrate the accuracy with which GPR data can be matched to excavation data and the improvement in target definition.
Instability analysis of the Villa Arianna site at Castellammare di Stabia (Naples)
Authors: Orlando Luciana
Published: February 2012

The detection of fractures using ground‐penetrating radar is usually obtained by analysing the attributes of reflected and scattered energy. In this paper, I test advanced processing of the GPR direct ground wave in order to successfully detect and map near‐vertical fractures that generally affect structures located in unstable areas. I show that the advanced processing applied to the GPR time window of a direct ground wave (embedding the early reflection arrivals) overcomes the problem that often occurs when detecting near‐vertical distensive fractures on the basis of reflected and scattered energy. For the validation of the processing, I use a synthetic model simulating an oblique fracture in a homogeneous and stratified host material. The theoretical radargrams show that an oblique vertical fracture induces variations in the ground direct wave, in terms of both two‐way traveltime and shape. Taking into account such evidences, I relate the fracture to the attributes of the delay time of the ground direct wave and the spectral analysis of a time window embedding the direct waves.

I test the advanced processing on real data acquired in the Villa Arianna archaeological complex (Naples) by analysing three kinds of floors composed of heterogeneous material, concrete and ancient mosaic. The last two floor types are affected by extensive cracks, which are visible on the floor. The analysis of attributes of actual data indicates that both attributes are effective for the detection of fractures in an homogeneous near‐surface layer and that the spectral analysis is more effective than the delay time of the ground direct wave for an heterogeneous layer. The selected GPR attributes are quickly and easily applicable in the detection and monitoring of near‐vertical distensive fractures because they can be calculated using GPR data acquired with a system deployed in reflection and continuous mode.
Analysis in Y Direction Reamer Error Based on Aspheric Parallel Grinding
Authors: Xu Jin Kai , Yu Hua Dong , Zhang Xue Jun
Published: February 2012

This paper introduces the affecting factors of tool clamping error of the axis direction in aspheric manufacturing process, and analyses the effects of tool clamping errors of the wheel along X and Y directions on processing area and contour error curve in depth in the aspheric manufacture parallel grinding, and calculates the relationship between tool clamping error of axis direction and aspheric shape error, and applies the theory in the machining process. The experiments show that the processing time decreases by 60% with satisfactory precision. The surface accuracy of 0.15 μm (0.237λ) of PV value and 0.023 μm (0.036λ) of RMS value can be achieved for 51.5 mm diameter aspheric surfaces. The theoretical analyses and error compensation methods are validated through the experiments, and the results show that the rapid process of aspheric surfaces can be realized.
Preparation and Electrochemical Properties of TiN-Nickel-Graphite Composite Anode Materials for Lithium Batteries
Authors: Feng Li Ming , Wei Xue , Liu Yan
Published: February 2012

The purpose of this study was to research the effect of tin-nickel alloy plating solution temperature, the dosage of graphite powder on the structure and composition of tin-nickel –graphite composite materials prepared by electrodeposition, discuss the relationship between carbon content and the specific capacity composite plating, charge and discharge efficiency, cyclic reversibility. The results show: control the tin-nickel alloy plating solution at 55-60°C, dosage of graphite powder below 10g.L-1 , [Sn2+]/[Ni2+]=1.7, then by electodeposition, a tin-nickel–graphite composite plating with about 80% of tin content ( mass fraction, similarly hereinafter) and carbon content below 7.82% can be obtained. The SEM shows that the composite plating is consist of small spherical particles forming network structure, with status of porous clusters. The charge/discharge cycle testing and cyclic voltammetry testing of the button cell composed of composite anode and lithium slices indicate: when the carbon content in composite plating increases, the specific capacity, charge/discharge efficiency and cyclic reversibility are obviously increased. When the carbon content reaches to 7.82%, the initial specific capacity is 1034.4mAh•g-1 , after 13 cycles, the specific capacity is 603.4mAh•g-1 , after 50 cycles, the specific capacity is 218.3mAh•g-1. The specific porous structure of composite plating and a good charge/discharge performance of graphite powder improve the electrochemical properties of composite anode materials.
Numerical Simulation of Fractal Tree-Shaped Flow Field Structures in PEMFC
Authors: Dong Jin Hua , Liu Shun Fang
Published: February 2012

The fractal tree-shaped structure such as tree, plant root, leaves, animal lung and so on is universal and unique in nature. These structures possess the symmetric micro-channel distributions and the efficient transport characteristics. They are considered to be an optimal network channel of mass transfer and heat transfer. The mass transfer and heat transfer feature of bipolar plate in proton exchange membrane fuel cell (PEMFC) is similar with animal lungs and leaves. In this paper, fractal theory is used to study tree-shaped flow field structure of bipolar plate in PEMFC. It is demonstrated by numerical simulation that fractal tree-shaped flow field structure can provide substantially flow-field distribution, current density and heat transfer compared to the traditional flow field structure.
Influence of Ink-Jet Paper Surface Characteristics on Color Reproduction
Authors: Zhu Zhi Wei , Chen Guang Xue , Chen Qi Feng , Yu Ming Guang
Published: February 2012

With the rapid development of color science, especially the ink-jet printing, the evaluation of the color copy effectiveness become one of the most important evaluation parameters in the ink-jet printing. Meanwhile, it makes the evaluation of the effectiveness of color reproduction become more and more quantitative. This paper selects four ink-jet printing papers with different types and physical properties, according to measurement and analysis of the whiteness, gloss, roughness, absorption and other performance parameters of the papers, it shows the effect from the various performance parameters of ink-jet printing paper to color reproduction. At the same time, the study of this paper offers a certain practical guidance to the selection of ink-jet printing paper as well as the improvement of replication precision of ink-jet printing.
The Degradation and BMP Release Dynamics of Silica-Based Xerogels Modified by Adding Calcium and Magnesium or Sintering Process
Authors: Li Xiao Sheng , Lin Wei , Xing Feng Lan
Published: February 2012

A new mesoporous silica xerogel used as biodegradable material was synthesized by improved sol-gel methods. The xerogel’s degradation character and property of releasing character for bone morphological protein (BMP)were modified by adding calcium (Ca) and phosphor (P) elements into pure silica xerogel, and uesing sintering processes, as well as adding magnesium (Mg) into silica xerogel. The differential thermal and thermogravimetric analysis (DTA-TG), X-Ray diffraction analysis(XRD), Fourier infrared spectrum analysis (FITR), N2adsorption-desorption analysis, Scanning electron microscope(SEM) and Transmitting electron microscope (TEM) observation were used to measure the thermal effects, crystalline state, pore diameter and specific surface area, surface morphology and inner structure of the xerogels. The xerogel’s degradability and BMP release were studied by simulated body fluid (SBF) immersion. The results indicated that the synthesized xerogels were mesoporous structure with pore diameter around 3 nm and the big specific surface area about 1000 m2/g.They were non crystall with hydroxyl and micro-molecular silica-oxygen groups. Xerogels dried at low sintering temperature degraded completely in 42 days in bursting manner and degraded in linear curves with sintering temperature increased as well as adding calcium and magnesium into xerogels. The BMP release behaviour from the Mg-xerogel dried naturally was in controlled manner.
Binder System Removal from Laminated Boron Carbide Ceramics
Authors: Liu Ying Ying , Qiao Ying Jie , Liu Ai Dong , Wang Yan
Published: February 2012

The binder system removal was studied in a laminated B4C ceramics prepared by tape casting and lamination with castor oil, polyvinyl butyral(PVB) and di-n-butyl phthalate (DBP) as dispersant, binder and plasticizer, respectively. Thermo gravimetric analysis and Fourier transform infrared spectromer was used to examine the degradation of the binder system. The degradation behavior of the pure organics, single sheet and laminated B4C body were investigated. The results indicate that nitrog4en was selected as the binder system removal atmosphere and two decomposition temperature ranges was obtained for organics. A model based on diffusion can be used to predict the binder system removal time for a certain thickness of laminated B4C.
Standard Parts of 3D Library Establishing Methods Discussed Based on UG
Authors: Jiang Tao , Li Liang Jing , Zhou Rui Li , Li Jin Guo , Lin Jing Shan
Published: February 2012

In view of the present mechanical rapid product development needs, this paper mainly discusses the use of UG for secondary development, use parameterized modeling method to establish the standard part library. And combined with examples expounding the second development method and procedure by use vc + + 6.0 and UG/open.
System Design of Spindle on High-Precise CNC
Authors: Wang Jun Feng , Du Xian Feng , Hu Qing Ming , Wang Shi Gang
Published: February 2012

With the rapid development of science and technology, Lathe will be sure to develop in the direction of high speed, high precision and high stability as the most basic and important production equipment in industry. The spindle is the one of important component in the lathe, of which static and dynamic characteristics is directly related to the machining precision and machining stability, and the performance of spindle system directly affects the overall machine specifications. Through the analysis of the characteristics of spindle, the ways and means of the spindle analysis are studied. For the requirements of static and dynamic characteristics analysis in the process of spindle design on high-precise CNC lathes hydrostatic, direct-drive spindle motor mode is used. Three-supporting structure is adapted in the layout of spindle bearing in order to improve the accuracy and stability of the spindle drive. The rolling bearing is used in auxiliary support, the front and rear radial bearing is used in master hydrostatic bearing. Thrust bearings are located on both sides of the former type of radial bearing to complete the selection of the spindle material and the design of the structural primary dimensions. It is meaningful to improve the specifications of CNC lathes, guide the design, generation and modification of the high precise CNC lathe and enhance static dynamic characteristics of the spindle and improve accuracy and stability of the machine tool processing.
Influence of Aggregates on Cracking Resistance of Concrete at Early Age
Authors: Chen Bo , Ding Jian Tong , Cai Yue Bo
Published: February 2012

In order to investigate influence of aggregates on cracking resistance of concrete at early age, four kinds of aggregates, i.e. syenite, basalt, marble and sandstone, were used for the test on cracking resistance of hydraulic concretes by the temperature stress testing machine. Analogy analysis was carried out with test results of concretes with two gradings of aggregates. The results show that aggregates affect elastic modulus, thermal expansion coefficients and tensile creep behavior of concrete at early age. However, the temperature rise of concrete was slightly affected by various types and gradings of aggregate. Moreover, the cracking temperature is reliably to be used to quantitatively evaluate the influence of aggregates on cracking resistance of concrete at early age.
A Novel Chaotic Neural Network with Radial Basis Function and their Application to TSP
Authors: Xu Nan , Liu Li Jie , Xu Yao Qun
Published: February 2012

A novel transiently chaotic neural network with radial basis function is proposed by analyzing the capability of chaotic search and the effect in solving combinational optimization problem. The character of Radial basis function is higher nonlinear and better function approaching ability. So a novel transiently chaotic neural network is presented by transferring sigmoid activation function into non-monotonous activation function which is composed by Contrary Multiquadric function and Sigmoid. This network is used to solve Traveling Salesman Problem (TSP), and the simulation result indicates that it can avoid the limit of being trapped into the local minima and converge to the global minima with high speed.
Research of Generalized Structure Module Modeling Based on Similar Feature Clustering
Authors: Gao Shu Ying , Li Li
Published: February 2012

he creation of generalized structure module model is studied in this paper. Firstly, the component of generalized structure module is analyzed by the form of sets, then the modeling process of generalized structure module is explained, also the method of similar feature clustering-based for modeling is presented. Finally, an example of the drafting module in flyer frame is given.
Optimisation of Geometric Parameters of Gears under Variable Loading Condition
Authors: Bozca Mehmet , Dikmen Ferhat
Published: February 2012

Optimisation of geometric parameters of gears under variable loading condition is studied. Bending stress is considered as objective function and contact stress is considered as constraint function. Bending stress and contact stress are calculated depending on zero tooth modification, positive tooth modification and negative tooth modification by using developed MATLAB program respectively. Obtained results are compared and presented graphically. It is concluded that tooth modification is effective parameter for optimisation of geometric parameters of gears under variable loading condition. By optimising the geometric parameters of the gears, such as, the module, number of teeth, helix angle, and face width, it is possible to obtain a light-weight-gears structures. All optimised geometric design parameters also satisfy all constraints.
A Powered Technique for Inserting Acetabular Cups
Authors: Naher Sumsun , O’Callaghan Daniel , Brabazon Dermot
Published: February 2012

This work focused to investigate the use of a powered automatic technique to insert acetabular cup implants. The use of a percussion hammer tool as a surgical instrument to insert acetabular cup implants was investigated in current work. Pull-out, lever-out and torque tests were carried out on cup implants inserted into test block specimens of polyurethane (PU) using specifically designed experimental setups as a means of comparing the current mallet and cup introducer (manual impaction) technique against the percussion hammer tool (powered impaction) technique. The experimental tests were based on calculating the maximum forces or moments of forces required to remove the cup implants from a test block specimen, which was representative of the acetabulum of the pelvic bone. It was found, the cup implants inserted using the powered impaction technique required a greater applied force, moment of force and torque in order to remove the cup from the cavity of the PU block specimen in the pull-out, lever-out and torque tests respectively. In terms of stability, the percussion hammer tool has the potential to improve the seating of cup implants within the cavity using a more precise and controlled technique, thus improving the over stability of the inserted cup implant.
An Investigation of Lateral Surface Hardness and Related Cutting Forces in One-Directional Ultrasonic-Vibration Assisted Turning
Authors: Razavi Hamed , Nategh Mohammad Javad , Soleimanimehr H.
Published: February 2012

The experimental investigation of UAT shows that the movement of cutting tool edge relative to the workpiece results from the cutting speed, feed speed and tools vibration in tangential direction affects the lateral machined surface of workpiece and leaves a repeating pattern of toothed regions on it. In UAT process, because of constant feed rate of tool toward workpiece, the cutting tool never separates from workpiece, though the tool rake face may separate periodically from chip in every cycle of vibration. This results in an increase in the surface hardness of the lateral machined surface in comparison with conventional turning (CT). The results of the present study confirm the advantage of UAT as far as the lower cutting force is concerned compared with CT. The higher surface hardness of the lateral surface observed in UAT causes the maximum cutting force to increase but the average force decreases with respect to CT.
Modeling and Dynamic Response Analysis of an Point Supported Plate by Using ANSYS and MATLAB
Authors: Demir Cihan , Alapan Yunus
Published: February 2012

The dynamic behavior of plates with mixed boundary conditions has been the subject of intensive study for many years due to its great importance in many engineering applications. On-trend approach in dynamic response analysis is to combine mathematical model, test results and computer simulation. Classical techniques of mathematical modeling of intricate structural systems for response analysis in frequency or time domain are tiresome and time consuming. In this study, a point supported rectangular plate considered and extraction of its system model from FE model, validated by the test results, by using commercially available computer programs such as Ansys and Matlab is demonstrated. State space mathematical model in principal coordinates obtained in Matlab from the modal analysis results of its FE model. Its modes sorted with respect to peak gain values, and the modes with the less contributions to the response truncated. To validate the accuracy of this method and truncation, transient responses from the full model with no reduction, truncated model, and Ansys are compared and found to be in accord with each other. Its demonstrated by plotting the indicated results of analyses, and emphasized the significant processing times between the conventional approach and stated method. It is concluded obvious that this study will make a good understanding in simplifying the dynamic analysis of vibration problems of plates.
Torsional Wave Propagation in Sandwich Hollow Cylinder with Pre-Strained Face (Core) Layers (Layer)
Authors: Akbarov S.D. , Kepceler T. , Mert Egilmez M. , Dikmen Ferhat
Published: February 2012

This paper studies torsional wave dispersion in a three-layered (sandwich) hollow cylinder with pre-strained face (core) layers (layer) made from high elastic materials the mechanical relations of which are described through the harmonic potential. The investigations are carried out within the scope of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies. The analytical expression is obtained for the low wave number limit values of the torsional wave propagation velocity. The numerical results on the influence of the initial strains of the face (core) layers (layer) of the cylinder on the torsional wave propagation velocity are presented and discussed.
Development of Advanced Broaching Tool for Machining Titanium Alloy
Authors: Sarwar Mohammed , Dinsdale Mike , Haider Julfikar
Published: February 2012

Broaching is a precision multipoint metal removal operation normally employed for manufacturing variety of complex parts having either internal or external features. Broaching can produce high precision and good surface finish at a high metal removal rate. The unique feature of a broach tool is that the feed/depth of cut for the teeth is built into the broach unlike other cutting tools. The tool design (e.g., rise per tooth and tooth geometry) play a vital role in the broach performance. A specially adapted machine tool modified to investigate a single broach tooth has been used. Cutting forces and material removal rate have been measured during experimental work for different combination of broaching parameters and broach tool geometry. The effect of the parameters on the surface quality produced has been established. The characteristics of chips formed have also been defined. Finally, optimum tooth geometry and rise per tooth have been recommended for tool performance, broached surface quality and efficient chip formation. The information provided in this paper will be beneficial for broach tool designers and manufacturing engineers.
Chip/Tool Interaction during Dry Machining of the TA6V Alloy
Authors: Calamaz Madalina , Coupard D. , Gutiérrez-Orrantia M.E. , Bega J. , Girot F.
Published: February 2012

During chip formation, material is subjected to high deformations and high strain rates which generate high pressures and temperatures. Cutting fluids have an important role but produce many constraints: cleaning of parts, environment quality degradation, cost increase, diseases as identified by the European Agency for Safety and Health at Work. Dry machining is one of the future challenges although its implementation remains delicate, in particular for TiAl6V alloy. This paper aims at correlating the contact conditions at the tool/chip interface with the tool wear to understand the wear mechanisms of carbide tools in dry machining. Numerical simulations, experimentally validated, allow pointing out that the temperature distribution at the tool/chip interface depends on chip type (continuous, serrated). For continuous chips, the temperature is fairly uniform and stationary throughout the interface. For segmented chips, a cold zone between two temperature peaks is observed and moves along the tool rake face during the formation of a chip segment. The evolution of the normal stress at the interface is similar for both types of chips at the beginning of the localization phenomenon. These pressure and temperature fields allow the titanium to diffuse into the tungsten carbide and form the mixed carbide (Ti, W)C, which is very sensitive to oxidation above 500°C. This could explain the attrition of the tool, due to the brittleness of the oxycarbides. Contact conditions and tool wear are finally correlated.
A New Approach to CNC Milling Machine Spindle Design
Authors: Buyuksahin Utku
Published: February 2012

During the technological development, some equipments remain mostly the first days design besides most of others change repeatedly. CNC Milling machines spindle design is one of these which remains mostly the same. With the existing design, in order to obtain the desired torque for metal milling process, the body of the spindle is made huge and heavy which causes the whole machine body to be constructed huge and heavy. In this study a new approach to CNC Milling Machine Spindle Design is made. The design changes the hob to be held indirectly instead of to be held directly at the lower end of the spindle. The huge spindle motor is fixed to the ceiling over the machine and a flexible steel rope is used to transfer the rotational motion. At the end of the steel rope, a planetary gearbox is fixed which is also fixed to the mobile part of the CNC construction. By this way, the required torque is obtained just at the milling process takes place and the motion transmission parts can be made light in weight like the whole construction would be made.
Finite Element Analysis of Rim Ring Rolling Forming of Bicycle Aluminum Alloy
Authors: Chen Dyi Cheng , Lai Bao Yan , You Ci Syong
Published: February 2012

The bicycle is not only a pollution-free method of transportation, but also has sport and recreation functions. Therefore, the bicycle attracted attention in now society gradually. This study uses the rigid-plastic finite element (FE) DEFORMTM software to investigate the plastic deformation behavior of a 7075 aluminum alloy workpiece as it is formed through a ring rolling die. This study systematically investigates the relative influences of ring rolling velocity, entering velocity, and workpiece temperature under various ring rolling forming conditions. The effective strain, effective stress, and workpiece damage distribution in the ring rolling process are also investigated. Results confirm the suitability of the proposed design process, which allows a ring rolling manufacturer to achieve a perfect design during finite element analysis.
A Study of Preform Design on Backward Extrusion for Improved Hardness Distribution
Authors: Kwan Chin Tarn , Chang Zhi Kai
Published: February 2012

In this paper, the finite element method is used to investigate the effect of preform shapes on the strain hardening distribution in the wall of the extruded cup of backward extrusion. A series of simulations on the backward extrusion with three different preform shapes (flat, concave and convex) and without preform using the FEM program DEFORM 2D was carried out, respectively. The influence of preform shapes on the effective strain distribution in the extruded wall was examined. A hardness vs. effective strain curve for an annealed AL6061 Aluminum was first obtained using a simple forging test in conjunction with FE simulations, then the curve was used to convert the effective strain distribution into the hardness distribution in the extruded wall. The results of FEM calculations reveal that the concave shape preform has the best effect on the hardness strengthening at the extruded wall of backward extrusion.
Application of Abductive Network and FEM to Predict the Optimal Blank Contour of an Inner Elliptic Flange from Flanging
Authors: Kwan Chin Tarn , Chang Jui Tsai , Lin Ching Tien
Published: February 2012

In this paper, the finite element method is employed in conjunction with the abductive network to predict the optimum blank contour of an inner elliptic flange with unevenness in the flanging process. Different flange heights combined with various aspect ratios of the inner elliptic flange are taken into account as the process parameters in this study. A finite element-based code is utilized to investigate the material flow characteristics under different process parameters, and the abductive network is then employed to synthesize the data sets obtained from numerical simulations, thus establishing a predictive model. From this model, an optimal blank contour for producing an elliptic inner flange with unevenness can be found.
Deformation Texture Evolution of Low Carbon Steel with Heterogeneous Structure
Authors: Boumaiza A. , Ayad A. , Rouag Nadjet
Published: February 2012

The present study examines deformation textures in low-carbon steel with microstructural heterogeneity. EBSD and XRD have been used in order to follow the evolution of the texture in relation with deformation evolution. The non-deformed material shows a {111} fibre texture (γ-fibre), with a main component {111} <112>. The deformation aptitude may be related for bcc metals to the evolution of this fibre texture component. To follow the evolution of the deformation textures, tensile tests were performed from 5% up to failure. During deformation, the {111} <110> deformation component sharpens. In the presence of this component in the non-deformed sheet, plastic flow is easy, while the grain reorientation from the initial orientation {111} <112> towards the bcc deformation orientation {111}<110> implies an important micro-constraint state, which is able to initiate cracking in the studied sheet during drawing. Heterogeneous structure that develops during deformation induces heterogeneous mechanical behaviour; noted this evolution is not predictable using global characterization techniques. The morphological analysis shows the micro-band presence. In a heterogeneous structure the risk of cracking seems to increase in the presence of small grains {111} <112 > clusters. The EBSD technique showed the adjustment of the grain orientation from the component {111} <112> towards the global deformation orientation {111} <110>. This process can explain the possibility of crack propagation in a globally ductile material characterized by a main component {111} <110>.
Investigation on the Microstructure and Mechanical Properties of New Al-Si Piston Alloys
Authors: Shabestari S.G. , Gholizadeh R.
Published: February 2012

Dense precipitation of various intermetallic compounds is a common feature in the microstructure of Al-Si piston alloys. In this investigation, microstructure of LM13 alloy and three high Cu-containing Al-Si piston alloys with different amounts of Ni, Fe, and Mn were studied by means of optical microscopy (OM) and scanning electron microscopy (SEM). Chemical composition of the phases was determined by using energy dispersive X-ray analysis (EDX). The precipitation of the phases was studied through thermal analysis of the solidifying samples. Also, tensile properties and hardness of the samples were measured. The results showed that the various intermetallics such as Al12(FeMn)3Si2, Al3Ni, Al9FeNi, and Al3CuNi precipitated during the solidification. The high Cu-containing alloy with optimum levels of Ni (1.8 wt.%), Fe (0.75 wt.%), and Mn (0.3 wt.%) has the highest tensile strength (250 MPa) and hardness (110 BHN) among the other alloys.
Influence of Packing Phase Parameters in the Optimization of Mechanical, Weight Reduction and Dimensional Properties of Microcellular Foaming Injection Molding of Polypropilene
Authors: Fernandez Angel , Muniesa Manuel
Published: February 2012

Microcellular foaming of injected plastics offers the possibility to manufacture parts with reductions in costs and weight if compared with conventional injection molding. For this reason there is an increasing interest in challenging applications such as HEV (hybrid and electrical vehicles) and lightweight material applications in general. Complexity of microcellular injection molding is very high because the final properties of the material obtained depend largely on the processing conditions and these in turn unalterable factors such as mold design and manufacturing. The shrinkage of the molded part must be applied as an oversize of the mold cavity in the design phase. Shrinkage of a microcellular foam depends on the reduction of foam density. Moreover, the piece is designed to get a mechanical performance and meet the dimensional tolerances. Knowing that the reduction of foam density implies a reduction of the mechanical properties and influences the final piece dimensions the conclusion is that the microcellular injection process has a very small process window to fit all these factors. This research focuses on two objectives. First is the variation of post-molding shrinkage in terms of reduction of weight to determine the process window. Second is the determination of mechanical properties which do not show a proportional reduction but exponentially with weight reduction components. The results obtained with a 750 Tons. injection moulding machine equipped with a MuCell plastication unit and a large spiral mold have shown small variations in the dimensions for a predetermined process window and smaller reduction of mechanical properties with weight reductions for 20% talc filled polypropylene. The goal of this applied research is that all experiments have been developed with scaled-industry tools (large injection molding machine, Mucell unit and mold and test parts) comparing with conventional injection molding.
Temperature Distribution Simulation for Pulsed Laser Spot Welding of Dissimilar Stainless Steel AISI 302 to Low Carbon Steel AISI 1008
Authors: Mahmoud Adel K. , Taha Ziad A. , Shehab Abeer A.
Published: February 2012

This paper describes the development of a computer model used to analyze the heat flow during pulsed Nd:YAG laser spot welding of dissimilar metals; stainless steel AISI 302 to low carbon steel AISI 1008. The model is built using ANSYS FLUENT 6.3 software where almost all the environments simulated to be similar to the experimental environments. A simulation analysis was implemented, based on conduction heat transfer, out of the key hole where no melting occurs. The effect of laser power and pulse duration was studied. Four peak powers 5, 5.5, 6.5 and 7 kW were varied during pulsed laser spot welding (keeping the energy constant), also the effect of four pulse durations 5, 6, 6.5 and 7 ms (with constant peak power), on the transient temperature distribution and weld pool dimensions was predicted ,using the present simulation. It was found that the present simulation model can give an indication for choosing the suitable laser parameters (i.e. pulse duration, peak power) during pulsed laser spot welding of dissimilar metals.
Experimental Investigation of Laser-Drilled Holes Variations Depending on Laser Drilling Parameters
Authors: Uslan Ibrahim , Erdogan S. , Keles O. , Usta Y. , Yilbas Bekir Sami , Tuc B.
Published: February 2012

Parameters on a CO2 laser machine effects the variations on hole diameters. In this study, a CO2 laser machine is used for drilling processes. Processing parameters are selected between 1.2-4 mm workpiece thickness, 2500-4000 W laser output power, -4 to 2 laser focus setting, 8-14 bar assisted gas pressure and 500-1200 Hz laser frequency. After the drilling process, with the diameter measurements, pictures were taken with an optic microscope then the effect of the processing parameters on hole diameter variations were investigated.
Modeling of Weld Lap-Shear Strength for Laser Transmission Welding of Thermoplastic Using Artificial Neural Network
Authors: Nakhaei M.R. , Mostafa Arab N.B. , Kordestani F.
Published: February 2012

Laser welding of plastic materials has a wide range of applications in the packaging, medical, electronics and automobile industries provided it can predict high quality welds compared with other joining methods. Laser welding process parameters can affect the quality of welds. In this paper, Artificial Neural Network (ANN) is used to model the effects of laser power, welding speed, clamp pressure and stand-off distance on weld lap-shear strength in laser transmission welding (LTW) of acrylic (polymathy methacrylate). A set of experimental data on diode laser weld lap-shear strengths was used to train and test the ANN from which the neurons relations were gradually extracted to develop a model. The developed ANN model can be used for the analysis and prediction of the complex relationships between the above mentioned process parameters and weld lap-shear strength. The results indicated that increase in laser power and clamp pressure increases the weld lap-shear strength whereas welding speed and stand off distance had a decreasing affect on shear strength at high value.
Use of Porous Alumina Bioceramic to Increase Implant Osseointegration to Surrounding Bone
Authors: Al-Khateeb Khalid A. S. , Mustafa Ammar A. , Faris bin Ismail Ahmad , Sutjipto Agus Geter Edy
Published: February 2012

A new experimental porous glass ceramic coating for dental implants was prepared with a new formula consisted of a sintered glass ceramic based on alumina, silica glass and boron trioxide. The resultant sintered objects were anodized by one step anodization method at a constant potential of 40V and at a temperature of 22°C. X-ray diffraction analysis was performed to investigate the phase structure of the new material in addition to SEM investigation for surface texture and pores size and distribution. The new experimental material was subjected to failure under universal testing machine for compressive strength. The results showed a promising material to use as coating for implants as X-ray diffraction exhibited an amorphous phase diagram for the material structure whereas SEM results revealed that the pores in the specimens prepared by anodization method were highly ordered and the mean average pore size was 6.5-8.5 nm. The compressive strength test showed that the test-porous glass ceramic coating has a mean numerical value of up to 7.5 MPa which indicates an ambitious result for the new material.
Simulation of Friction Stir Processing with Internally Cooled Tool
Authors: Albakri A.N. , Mansoor B. , Nassar H. , Khraisheh M.K.
Published: February 2012

Friction stir processing (FSP) is considered to be a promising sustainable technique for grain refinement of metallic alloys. The heat generated during FSP promotes dynamic recrystallization in processed material which is essential for grain sub-division process. However, excessive heat generation can lead to high temperatures of >300°C that may cause abnormal grain growth in the processed material. On the other hand, repetitive high temperature heating cycles can reduce the lifetime of the FSP tool. Therefore, it is essential to manage the process heat not only to achieve homogeneity and finer grain sizes in the processed material but also to reduce tool wear. In this work, friction stir processing of AZ31B Mg with an internally cooled FSP tool is simulated by a three-dimensional CFD model. We have studied the effect of rapid tool cooling on temperature and flow stress distribution in processed material. Additionally, the grain size and hardness of the processed material is estimated by using Zener-Holloman and Hall-Petch based relationships. It was found that FSP with internally cooled tool is a promising approach that effectively controls temperature levels during processing. Therefore it enables the achievement of better mechanical properties by effective grain refinement and has a positive effect on tool life.
The Strain Energy Tuning of the Shape Memory Alloy on the Post-Buckling of Composite Plates Using Finite Element Method
Authors: Rasid Zainudin A. , Mazlan Saiful Amri , Amran Ayob , Zahari Rizal , Majid Dayang Laila , Rafie Azmin Shakrine Mohd
Published: February 2012

This paper presents a geometric non-linear finite element model of shape memory alloy composite plates and its source code in order to determine critical loads and to trace post-buckling paths of the composite plates. A numerical study was conducted on symmetric and anti-symmetric angle-ply and cross-ply composite plates. Buckling and post-buckling improvements of composite plates due to the shape memory effect behaviour of shape memory alloy were carried out. The pre-strained shape memory alloy wires were embedded within laminated composite plates so that recovery stress could be induced with the heated wires. The methods of active property tuning and active strain energy tuning were applied to show the various effects of the shape memory alloy on the studied behaviour. The result showed that significant improvements occurred in the critical loads and the post-buckling paths of the symmetric and anti-symmetric angle-ply and the symmetric cross-ply composite plates due to the active strain energy tuning method. In the case of the anti-symmetric cross-ply composite plate where bifurcation point did not exist, the post-buckling path was substantially improved.
Incorporation of TiC Particulates on AISI 4340 Low Alloy Steel Surfaces via Tungsten Inert Gas Arc Melting
Authors: Mridha S. , Idriss A.N.Md , Baker T.N.
Published: February 2012

Surface cladding utilizes a high energy input to deposit a layer on substrate surfaces providing protection against wear and corrosion. In this work, TiC particulates were incorporated by melting single tracks in powder preplaced onto AISI 4340 low alloy steel surfaces using a Tungsten Inert Gas (TIG) torch with a range of processing conditions. The effects of energy input and powder content on the melt geometry, microstructure and hardness were investigated. The highest energy input (1680 J/mm) under the TIG torch produced deeper (1.0 mm) and wider melt pools, associated with increased dilution, compared to that processed at the lowest energy (1008 J/mm). The melt microstructure contained partially melted TiC particulates associated with dendritic, cubic and globular type carbides precipitated upon solidification of TiC dissolved in the melt; TiC accumulated more near to the melt-matrix interface and at the track edges. Addition of 0.4, 0.5 and 1.0 mg/mm2 TiC gave hardness values in the resolidified melt pools between 750 to over 1100Hv, against a base hardness of 300 Hv; hardness values are higher in tracks processed with a greater TiC addition and reduced energy input.
Bending Effect on Cutting Characteristics of Polycarbonate Thick Sheet Subjected to Indentation of Heightwise-Asymmetric Wedge Blades
Authors: Nagasawa Shigeru , Masaki Yuuya , Fukuzawa Yasushi , Mutoh Yoshiharu
Published: February 2012

This paper describes for verification of bending effect on the performance of the heightwise-asymmetric plunge cutting method, which was composed of an upper-wedge blade and a lower-wedge blade embedded in the lower-counter plate, in order to apply this cutting method for a polycarbonate (PC) thick sheet. By varying the tip angle αU and the tip thickness wU of lower blade embedded in the counter plate, and combining a standard steel cutting rule of 42° center bevel blade, the sheared profile of two kinds of PC worksheet (the thickness of which was chosen as t=0.5, 1.0 mm) was experimentally investigated. Through this experiment, it was found that the sheared profile (the necked height ηn, the upper inclination angle β, the lower inclination angle βU) of PC worksheet was primarily characterized by the normalized lower tip thickness wU/t. The difference of sheared profile was explained using the Prandtls punching solution for two kinds of PC worksheet. Furthermore, by varying the heightwise position of lower blade tip, the bending effect on sheared profile of worked sheet was experimentally verified.
Yttria-Doped Zirconia-Hydroxyapatite Composite Coating on Cp-Ti Implants by Biomimetic Method
Authors: Karakas Aysu , Yoruç A. Binnaz Hazar , Erdogan Duygu Ceylan , Elkoca Oktay
Published: February 2012

Titanium (Ti) and Ti-alloys are often used in dental and orthopedic applications because of their good mechanical properties and biocompatibility. The advantages of Ti and Ti-alloys are its superior corrosion resistance, high fatigue strength and low elastic modulus which reduce stress shielding. Morover biocompatibility of them can be improved coating with bioceramics such as hydroxyapatite (HA) or other ceramic composites. The hydroxyapatite [Ca10(PO4)6(OH)2, H is frequently used as a coating material on the surfaces of Ti-based medical implants to improve the bone fixation and thus the lifetime of the implant is increased. However, the main weakness of HA lies on its poor mechanical strength that makes it unsuitable for load-bearing applications. An attractive way to produce the tougher HA is to use composite powders such as Yttria-Doped Zirconia-Hydroxyapatite (YSZ-HA) consisting of 8 mol% yttria-stabilized tetragonal zirconia (YSZ) so that the apatite phase increases the biocompatibility and zirconia (ZrO2) phase improves the strength. Y2O3 addition into zirconia can stabilize the tetragonal phase at room temperature (YSZ) and the tetragonal phase plays a major role to increase the fracture toughness. In the present study yttria-dopped zirconia powders by using ZrO(NO3)2.xH2O and Y(NO3)3.6H2O were produced to synthesize HA-YSZ composites. In accordance with this purpose, at the first step, Ca (NO3)2.4H2O, (NH4)2HPO4 and YSZ powders were dissolved in simulated body fluids (SBF) to obtain sol. The gelatin solutions with different concentration were added into sol to provide the gelation. Then the surfaces of Ti implants were soaked in this solution. The coating rate of Ti samples was arranged as 14 cm/s and coated implants were sintered at 900°C. Structural analysis of coated powders was obtained by using XRD. Morphological examinations and coating thickness were investigated by SEM. After the sol-gel solution was dried at 80°C, dried-powder was sintered at 900°C. Sintered powders were analyzed by FT-IR to determine any gelatin residue.