bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Material Flow Analysis of Steel Resources in China Based on Circular Economy Theory
Authors: Wang Peng , Jiang Ze Yi , Geng Xin Yi , Hao Shi Yu
Published: September 2013

The circular economy (CE) is a new development strategy for China to alleviate the contradiction between rapid economic growth and the shortage of raw materials and energy. As the basic material, steel is a key driver of the world's economy. Therefore, it is essential to set up CE indicators system to understand the mechanism of steel resources role in the circular economy. In this paper, a national level material flow evaluation framework based on CE theory is presented at the first. Then steel resources national lifetime cycle diagram is built based on dynamic Material Flow Analysis (MFA) method considering the steel lifetime circular flow characteristics. Under the guidance of this diagram, the material flow results of various stages (such as production process, fabrication & manufacturing process, in-use process, etc.) of steel lifetime cycle between 2001-2010 in China is obtained, including the end-of-life scarp amount of nine downstream industries. The results indicate that China steel resources has made gratifying achievements in improving productivity, reducing energy consumption and related pollution emission, but the degree of overall circulation remains to be improved urgently. In the end, a sketch of the future relevant policy recommendations are provided.
Vibration Tests at Thin Stainless Steel Sheets Joined by CMT Pulse with CuSi3 Filler Material for Determination of the Elasticity Modulus
Authors: Bereteu Liviu , Medgyesi Tiberiu , Popescu Mihaela , Drăgănescu Gheorghe , Rosu Radu Alexandru , Simoiu Dorin
Published: September 2013

t is presented a method for determining the mechanical characteristics based on the vibration response of the CMT (Cold Metal Transfer) joints from thin sheets of stainless steel joined with CuSi3 filler wire. The experimental results obtained by vibration testing will be compared with the theoretical results, and with those obtained by classical methods from stress-strain diagram. Technical details are given also for obtaining these joints (parameters, equipment specifications) indicating also their applicability.
Technological Development Perspectives and Experimental Results of MIG Welding Soldering
Authors: Dana Dragos , Vizureanu Petrică , Cimpoeşu Ramona , Achiţei Dragos
Published: September 2013

In the welding process of metals, two materials are joined by a filler material with low melting point (below 450 °C), also below the melting point of materials to be joined. The braze-welding filler material has a melting point over 450 °C to 1000 °C. Filler material is distributed between two surfaces of the joint by capillary action close, the blended material is applied on an electrode specially manufactured and intended operation. This paper proposes an analyze of the techniques, feathers, technology requirements, process gaseous, materials (standard data base) and conditions used in braze-welding processes. The secret of solder bonding and weld seems to be the opening that supposes to be small. Two methods are proposed and analyzed for welding process based on braze welding. Scanning electrons microscope and EDAX detector were used to characterize the weld line by micro-structural and chemical point of view. The microstructure analysis concentrated on the weld line area presents reduced dimensional variation and a modification of the materials surface smoothness. Chemical elements distribution exhibits an increase of carbon percentage on the weld line and a decrease of iron in the same time and area.
The Forming Mechanism of Surface Defects on Machined Surface in High-Speed Cutting of SiCp/Al Composites
Authors: Wang Yang Jun , Pan Ming Qiang , Chen Tao , Chen Li Guo
Published: September 2013

For investigating the machined surface defects in high-speed cutting of SiCp/Al composites. The simulation and experiment of high-speed cutting process is done. The simulation of high-speed cutting process using the Cowper-Symonds model is established to explore the forming mechanism of the machined surface defects. The results show that the machined surface defects include small pit, big pit, groove and the raised particle. The experiment which uses the same cutting parameters with the simulation of FEM (Finite Element Method) model is carried out to verify the results of FEM simulation. The results indicate that the forming mechanism of machined surface defects prove to be true.
Crashworthiness Design Analysis of Vehicle Door Using Simulation Experiment Design and Multi-Objective Genetic Algorithm
Authors: Wang Xiao , Lou Wan Li , Liu Hui Xia , Liu Da Ling
Published: September 2013

A FE model is built based on one vehicle door, the thickness of door's main components for absorbing energy is considered as the design variable. Firstly, a screening experiment is implemented by using Plackett-Burman design, and the prominent components for crashworthiness are selected. Then, the Latin hypercube experiment design is performed again. The approximation model of polynomial response surface is built by the Least Squares Regression according to the experimental results. At last, the approximation model, of which the objective function are the maximum internal energyand the minimum mass sum of all variables, and the constrain function is the maximum impact force, is optimized by using multi-objective Genetic Algorithm (MOGA). The results of the optimization show that the mass of all design variables and the max impact force are reduced by 4.12% and 4.43%, respectively, and the maximum internal energy is increased by 2.3%. The crashworthiness of vehicle door is improved, and it provides the technological support for the safety and light weight design of the whole vehicle door.
The Influence of Micro-Texturing Dimple on the Bearing Capacity of the Elastohydrodynamic Lubrication Based on CFD-FSI Fluid-Solid Coupling
Authors: Liu Jiang , Liu Hui Xia , Li Jian , Feng Shi Lin , Wang Tian Yu , Wang Xiao
Published: September 2013

Based on the CFD-FSI fluid-solid coupled method, the equivalent elastohydrodynamic lubrication model of the micro-texturing dimple surface on the condition of the medium velocity and medium load, low velocity and heavy load, high velocity and heavy load, low velocity and light load and high velocity and light load is respectively solved by numerical method in this paper. And obtain the oil film pressure distribution curve and the oil the film thickness distribution curve on the conditions of steady state, and analyze the influence of micro-texturing dimples on the bearing capacity of the equivalent elastohydrodynamic lubrication model. Analysis results show that: compared with the corresponding minimum film thickness on the conditions of smooth surface, the minimum film thickness of micro-texturing dimple surface on the conditions of the medium velocity and medium load, low velocity and light load is increased, which indicates the bearing capacity of the equivalent elastohydrodynamic lubrication model of the micro-texturing dimple surface is increased; while the minimum film thickness of the rest conditions is decreased, which shows that the bearing capacity of the equivalent elastohydrodynamic lubrication model of the micro-texturing dimple surface is decreased. The study in this paper lays the foundation for the design and optimization of the micro-texturing dimple.
The Establishment of Agricultural Engineering Information System for Farmer Cultivation
Authors: Li Hui Jing , Tong Guang Ji
Published: September 2013

By means of information to improve the quality of farmers, it is not only an important part of constructing the modern agriculture, but also the basic premise and guarantee to cultivate the new occupation farmers and to construct new countryside. In this paper, we analysis the significance on agricultural information to promote the occupation farmers cultivation engineering, and we use SWOT analysis method, analysis the construction of current agricultural informations strengths, weaknesses, opportunities and threatens, putting forward the suggestion that make the agricultural information as the carrier, and develop the construction of occupation farmers, it is namely promoting agricultural information resources integrating and sharing, innovating rural grass-roots information service mode, constructing rural education information service platform which is regard knowledge push as construction of core and basing on cloud computing environment of agricultural information education system.
Ratcheting Properties of Steel 45 and 42CrMo under High Cyclic Stress
Authors: Li Yue Feng , Pan Xu Dong , Wang Guang Lin
Published: September 2013

Disposable mechanical elements are widely used in many fields such as aerospace and military industries. It is known for their extremely short work time which is quite different from general mechanical elements. The stress level of disposable mechanical elements is much higher than general mechanical elements. In this situation, the traditional fatigue fracture failure will be replaced by fatigue elastic failure used in the design of disposable mechanical elements. The fatigue elastic failure is closely related to the ratcheting properties of materials. Therefore, this paper focuses on the ratcheting properties of typical cyclic softening materials steel 45 and 42 CrMo. The fatigue elastic failure phenomenen of these two materials are shown through the stress control tests.
Research of Automatic Measurement Technology for Oil Thimble External Thread Parameters
Authors: Wei Yong Geng , Wang Zhong Xian
Published: September 2013

There are many problems for manual measurement of oil thimble external thread parameters: human error, low efficiency, low precision for measuring instruments and high abrasion for its measuring head, so photology automatic measurement method is adopted. Automatic measurement is finished by the following method: obtaining image by plane Matrix CCD and a two-DOF motion platform, extracting digital image by digital image processing techniques, getting the thread parameters by reasonable algorithms and digital image detection technology. Through field experiment of measuring instrument prototype for TYG type oil thimble external thread parameters, Data error is very small, obtained data is precise, measuring efficiency and precision for measuring instrument are high, there is no equipment abrasion problem for the measurement process, the method is feasible.
Fast Surface Construction and NC Milling Based on 3D Scanning
Authors: Wu Zheng Hong , Zhou Qing Kun , Fan Da Peng , Zhu Jian Neng , Wang Jian Min
Published: September 2013

Construction of a rapid surface and processing is an effective way to improve the manufacturing efficiency, this paper linked the 3D scanning, fast surface construction and NC closely, described the whole process of surface data acquisition and processing, surface construction and the process of NC machining. The outer surface of the mouse was scanned from multiple angles by using 3D CaMega scanner, a plurality of point cloud was obtained, the point cloud processing, triangle face processing construct refinement of the model surface and grid lines were all processed in Geomagic Studio software, through adjustments, NURBS surface was generated. Also the mould surface of the mouse was constructed in the UG NX software. This paper wrote the machining process, Programmed NC Milling in UG NX software, generated the trajectory of rough and finishes machining as well as the programs of machining tool. Also CNC milling was processed CNC machining center.
A 5-DOF Combined Robot Platform for Automatic 3D Measurement
Authors: Qian Jun , Zhu Hua Bing , Wang Shu Wang , Zeng Yi Shan
Published: September 2013

This paper describes the reconstruction process of a 3P2R type combined robot platform on the basis of a 2-axis linearly moving worktable. An additive 3-DOF manipulator installed above the worktable has one prismatic and two revolute joints by using a novel integrated ball screw and spline axis. The control system of the platform is composed of a 4-axis motion control card and a PLC. Meanwhile, this paper deduces the kinematic equations of this special combined platform for measurement. The 3P2R type platform could be used to measure 3D contour of small work piece automatically.
Research on Modeling and Simulation Analysis of Direct Drive System in Simulink and Simscape Environment
Authors: Liao Hong Bo , Fan Shi Xun , Hei Mo , Fan Da Peng
Published: September 2013

In order to verify and analysis the theory model of direct drive system, the methods of computer-aided modeling and simulation analysis in Simulink and Simscape environment were presented. Based on the theory model of direct drive system, simulation models were constructed in two kinds of different environment, the model building and analysis process were detail introduced, the simulation results were compared and experiment verification. The simulation and experiment results showed that the relative error of time domain response of simulation results under two kinds of environment is within 4%, the relative error of frequency domain response is within 4.5%. Comparing simulation results under Simulink environment with the real test results, the relative error of time domain response is within 20%, and the relative error of frequency domain response is within 15%. The consistence and correctness of the two methods are verified, the proposed methods can also be applied to modeling and simulation analysis of others Mechatronic servo system.
Development of Field Control System of Automated Guided Vehicle Based on Wireless Local Area Network and CAN Bus
Authors: Wang Yan , Yu Zhong Da , Bao Chen Xing , Shao Dong Xiang
Published: September 2013

In this paper, we realize a real-time communication based on wireless local area network (WIFI) and controller area network (CAN) bus and develop a distributed control system for an automated guided vehicle (AGV). The system consists of two levels: (1) communication between AGVs and main computer based on WIFI, (2) communicationg between control units of AGV based on CAN bus. A real-time operating system μC/OS-II was used to control time, which significantly reduces the time for program and improves development efficiency. Finally, a small-size distributed AGV controller is developed as the main control unit of AGV and a distributed I/O system is developed based on it.
Road Engineering Optimization Based on Driving Reaction
Authors: Cao Zhao , Wu Xiao , Yang Qing
Published: September 2013

With the increasingly outstanding of the traffic safety issue, the human factors in People-Vehicle-Road System are being emphasized gradually. Takes Jinhua suburb asphalt mountain road (two-lane, multiple steep slopes) for example, this study focuses on road engineering response analysis on driving reaction, design optimization of road engineering base on driving response. A driver over 3 driving years steered 5-seat car in 4 kilometers long experimental road, kept the vehicle speed (V) under 40km/h. Heartbeat rate of the driver was monitored by dynamic Holter through driving process. The analysis shows that there is a linear positive correlation between Heart beat growth rate (Ni) and V, a nearly positive correlation between lateral force coefficient (μ) and Ni, and nearly inversely proportional between plane curve radius (R) and slope (i). It should decrease R appropriately when road slope (i) much sharply in road alignment design. There is a polynomial relation between Ni, V and R. As R increases, both Ni and V reduce firstly, and then rise. When R ranges from 240 to 500 meter, stress gradually ease; while R exceeds 500 meter, driving reaction tension gradually rise. R<550 m, i <6% and slope length under 300 m in the experimental road. When instructional speed <40km/h, then Ni was 30.2% and μ was 0.25. Its benefit for driving safety to keep drivers in appropriate tension in such situation.
Multi-Factors Interaction Effects of Process Parameters on the Joint Strength of Laser Transmission Joining between PC and PA66
Authors: Huang Chuang , Gao Yang Yang , Liu Hui Xia , Chen Hao , Li Pin , Wang Xiao
Published: September 2013

This paper presents a laser transmission joining (LTJ) experiment between thermoplastic Polycarbonate (PC) and glass reinforced nylon (PA66GF) using diode laser equipment. Laser transmission joining experimental design and experiment are carried out according to a single process parameters window. Response surface methodology (RSM) in Design-Expert v7 software is employed to develop mathematical models between LTJ process parameters and joint strength. The interaction effects of joining process parameters (line energy, spot diameter, clamp pressure) on the joint strength are investigated using analysis-of-variance (ANOVA), the result shows that the interaction effect of line energy and spot diameter has maximum influence on the joint quality. Finally, the predicted values from mathematical models developed by RSM are compared with the experimental values and it is found that they are nearly agreed with each other. The purpose of predicting joint strength based on reasonable process parameters is achieved.
Thermally Stimulated Depolarization Current in 3 Mol% Yttria-Doped Zirconia
Authors: Horiuchi Naohiro , Tsuchiya Yu , Nozaki Kosuke , Nakamura Miho , Nagai Akiko , Yamashita Kimihiro
Published: September 2013

3 mol% yttria-stabilized zirconia (YSZ) powders were sintered into pellets. The YSZ ceramics were electrically polarized by applying dc voltage at an elevated temperature. After cooling the samples to room temperature, the polarized YSZ ceramics were heated at a constant heating rate. The formed polarizations were relaxed with increase of the increase temperature. The depolarization current was measured as thermally stimulated depolarization current (TSDC). Each of the TSDC spectra had two peaks located at lower and higher temperatures. The lower and higher peaks are attributed to dipole polarization and space charge polarization, respectively.
Structure and Properties of Thin Films Consisting of Single Crystalline BaTiO3 Nanocubes
Authors: Mimura Kenichi , Kato Kazumi
Published: September 2013

Single crystalline BaTiO3nanocubes, which were synthesized by hydrothermal reaction with organic surfactants and additives, were assembled in order and directly on the substrates by dip-coating method using the dispersed solution. After evaporation of solvent, the orderly assembly of the nanocubes was developed over the large region in about several tens of micrometers square. It can cover whole surface of the substrate. The microstructures of the nanocube assemblies were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Electrical property of the nanocube-assembled film was characterized by piezoresponse force microscopy (PFM). The d33-V curve showed ferroelectric hysteresis and saturation behaviors under high applied voltage.
Preparation of Barium Titanate/Strontium Titanate Nanocube Accumulation Ceramics and their Dielectric Property
Authors: Tsukamoto Shuhei , Iwatsuki Shogo , Fujii Ichiro , Nakashima Kouichi , Wada Satoshi
Published: September 2013

The barium titanate (BaTiO3, BT) epitaxially coated strontium titanate (SrTiO3, ST) (BT/ST) nanocube accumulation ceramics were successfully prepared by a sorbothermal method, with epitaxial interface between ST and BT, and as reference, the BT/BT nanocube accumulation ceramics were also preapred. These dielectric properties were measured for the both accumulation ceramics, and it was clearly obserbed that there was significiant difference between BT/ST and BT/BT nanocube accumulation ceramics in the dielectric properties under low and high electric fields, and the origin of the result was discussed.
UV-Visible Faraday Rotators Based on Rare-Earth Fluoride Single Crystals: LiREF4 (RE=Tb, Dy, Ho, Er and Yb), PrF3 and CeF3
Authors: Vasyliev Valentyn , Villora Encarnacion G. , Nakamura Masaru , Sugahara Yoshiyuki , Shimamura Kiyoshi
Published: September 2013

High optical quality LiREF4(RE = Tb3+, Dy3+, Ho3+, Er3+and Yb3+), PrF3and CeF3single crystals have been grown by the Czochralski technique. Their magneto-optical properties have been measured and analyzed in detail in the ultraviolet-visible wavelength region, and their figures of merit as Faraday rotators have been determined. CeF3presents superior properties above 300 nm, showing a figure of merit higher than that of the reference material, terbium-gallium-garnet, which is nowadays used in the visible-near infrared. PrF3is the best rotator for the 220-300 nm range. Towards shorter wavelength and in the vacuum ultraviolet, it is shown that the LiREF4crystals are unique rotators.
Influence of Catalyst Loading Method on Titania-Based Optical Hydrogen Gas Sensing Properties
Authors: Hamagami Junichi , Araki Ryo , Onimaru Shohei , Kawamura G. , Matsuda Atsunori
Published: September 2013

We reported that titania ceramic coating loaded with palladium catalyst worked as an optical hydrogen gas sensor at room temperature. The palladium metal of this sensor worked as a catalyst not only for room-temperature operation but also for high selectivity to hydrogen gas. Precise control of metal/ceramic interface between the titania and the palladium was very important in order to improve the sensor performance such as sensitivity, response time, recovery time. Influence of a difference in palladium-catalyst loading method (photodeposition and sputtering) on the optical hydrogen gas sensing properties for the titania-based sensor was investigated. It was found that the catalytic loading process significantly affected the optical hydrogen characteristics of the titania-based coating.
Improvement of Insulation Reliability of BaTiO3-Based Ceramics Using Mixed Conductive Electrode
Authors: Yoshidome Daichi , Hoshina Takuya , Takeda Hiroaki , Sakabe Yukio , Tsurumi Takaaki
Published: September 2013

The insulation degradation of BaTiO3-based ceramics under direct-current field is caused by the migration of oxygen vacancies. To improve the reliability of BaTiO3-based ceramic capacitors, conventional approaches are focusing on dielectrics, mainly working on suppressing the total amount of oxygen vacancies towards the cathode. In this study, we newly focus NOT on the dielectrics but on the electrodes, and tried to improve the reliability of BaTiO3-based ceramics by suppressing the segregation of migrated oxygen vacancies. La0.8Sr0.2MnO3 (LSM) is a mixed ionic-electronic conductor that generates oxide ions from gas-phase oxygen. We expected that LSM would compensate for migrated oxygen vacancies when using it as the cathode of a BaTiO3-based ceramic capacitor. The results of our highly-accelerated life tests indicate that the reliability of BaTiO3-based ceramics improved when LSM porous ceramics was used only as the cathode, (NOT the anode).
Leakage Current and Polarization Properties of (Bi0.5Na0.5)TiO3-BaTiO3 Single Crystals
Authors: Hirano Kiyotaka , Onozuka Hiroaki , Kitanaka Yuuki , Noguchi Yuji , Miyayama Masaru
Published: September 2013

Single crystal of ferroelectric (Bi,Na)TiO3BaTiO3(BNTBT) with tetragonalP4mmstructure grown by a top-seeded solution growth (TSSG) method at a high oxygen pressure (PO2) of 0.9 MPa and their properties were compared with those of the crystals grown at aPO2of 0.1 MPa. The crystals obtained atPO2= 0.9 MPa exhibited a remanent polarization (Pr) of 54μC/cm2, which was much larger than those of the crystals grown atPO2= 0.1 MPa (20μC/cm2). It is suggested that the largePris attributed to a low oxygen vacancy concentration.
Energy Dispersive Techniques Using X-Ray Fluorescence with Primary X-Rays for Human Hard Tissues Analysis
Authors: Miculescu Florin , Pencea Ion , Miculescu Marian , Antoniac Iulian , Ciocan Lucian Toma , Ernuteanu Adrian
Published: September 2013

Among others, biomedical research is conducted for the systematic collection and analysis of data from which general conclusions can be drawn and which can increase the life quality of the patients. Given these issues, the aim of the research presented in this paper is to analyze the concentration of heavy elements from the human body, using complementary analysis methods, based on the energy dispersion spectrometry (EDS) technique.
Investigation of a Mechanical Valve Impairment after Eight Years of Implantation
Authors: Buzila Cosmin Alexandru , Antoniac Iulian , Miculescu Florin , Dumitrescu Marius , Droc Ionel
Published: September 2013

A 55-year-old female who undergone mitral valve replacement eight years ago with a mechanical graft, presented accusing sudden decrease of effort tolerance and two episodes of pulmonary edema in the last month. Anamnesis, physical examination, electrocardiogram (ECG), transthoracic echocardiography and coronarography were performed. The mechanical valve leaflets and the tissue surrounding the prosthetic ring were evaluated by: optical microscopy (hematoxylin eosin stain and immunohistochemistry), scanning electron microscopy (SEM) and EDAX analysis (Energy Dispersive X-ray spectroscopy). Anamnesis: inferior myocardial infarction in 2006, congestive cardiac insufficiency, pulmonary hypertension, and arterial hypertension. Clinical examination and ECG: minimal perimaleolar edema bilateral, sinus rhythm on admission. Transthoracic echocardiography: 55% ejection fraction, a pression gradient across the mitral valve (Gmax/Gmed= 24/11 mmHg), tricuspid regurgitation, and pulmonary hypertension. A mitral prosthetic valve’s leaflet was found immobile. No thrombus was evidenced. Coronarography: an immobile graft’s leaflet, stenoses on the right coronary artery, stenosis on left anterior descending artery and occlusion at the circumflex artery emergence. The prosthesis was replaced, and two coronary artery bypasses were performed. Macroscopic examination: a fibroconjunctive tissue expansion in close contact with the leaflet. Histopathological evaluation: muscle cells with altered phenotypes, fibroblasts along with fibrous connective tissue and calcium depots areas. SEM evaluation: tissue depots on the immobile leaflet, suggesting that the connective tissue expansion was blocking the leaflet’s movements. EDAX analysis: the metallic leaflets surface was made of tantalum; sodium, calcium and chloride deposits were also detected. Graft failure was caused by the tissue proliferation affecting leaflet’s mobility. SEM is a viable method for failed cardiovascular grafts investigation.
Clinical, Biomechanical and Biomaterials Approach in the Case of Fracture Repair Using Different Systems Type Plate-Screw
Authors: Ionescu Razvan , Cristescu Ioan , Dinu Mihaela , Saban Rami , Antoniac Iulian , Vilcioiu Daniel
Published: September 2013

Many researchers perform different research in the area of ostheosznthesis metallic implants used in orthopedic surgery. The main goal of internal fixation is to achieve full operation until patient recovery. Although implants are intended to withstand until bone consolidation in some cases problems occur due to accelerate wear and corrosion processes. The aim of the present study was to determine the causes leading to adverse reactions of the surrounding tissues in case of three implants for osteosynthesis type plate-screw.
Obtaining and Characterization of Biocompatible Co-Cr as Cast Alloys
Authors: Geantă Victor , Voiculescu Ionelia , Stefanoiu Radu , Chirita Ioana
Published: September 2013

Biocompatible metallic materials used for surgical implants in human body should have superior mechanical properties, as: microhardness, wear resistance, tensile strength, elongation, fracture toughness, creep resistance etc. These results can be also obtained by strict setting and controlling of chemical composition, by adding chemical elements that lead at the improvement of the mentioned properties. In this paper has been presented experimental researches regarding the obtaining process of some biocompatible Co-Cr cast alloys, having different chemical compositions, using the method of vacuum induction melting (VIM). After the obtainment process, samples were characterised from microstructure and microhardness point of view.
Nano-Iron Oxides Used for Environmental Applications
Authors: Predescu Andrei , Matei Ecaterina , Predescu Andra Mihaela , Berbecaru Andrei , Vladutiu Liana
Published: September 2013

The paper emphasizes the importance of use the nano-iron oxides as treatment materials for wastewaters decontamination, having in mind the size of these compounds and specific surface area suitable for retaining toxic metals such as chromium or cadmium presented as major pollutants for industrial wastewaters. Also, the magnetic properties of the nano-iron oxides offer the possibility of a fast removal of these from the system, after wastewaters treatment. The obtaining of some core-shell composites with nano-iron oxides as core represent an advantage because of the dissolving tendency of the nano-iron oxides under acidic conditions, the situation being common to the industrial wastewaters.
Calorimetric Analysis of a Mg-Zn-Zr Alloy Processed by Equal Channel Angular Pressing via Route A
Authors: Dumitru Florina Diana , Ghiban Brandusa , Cabrera Jose María , Higuera-Cobos Oscar Fabián , Gurau Gheorghe , Ghiban Nicolae
Published: September 2013

Being the lightest structural element, magnesium and its alloys has attracted significant interes in the last years, but because of its hexagonal close packed structure, magnesium presents relatively low strength and ductility. One of the methods to improve the mechanical properties of the processed materials is through Severe Plastic Deformation (SPD). ZK60 magnesium alloy samples were subjected to 4 passes of equal-channel angular pressing (ECAP) at a processing temperature of 250°C, following route A. The microstructure was determined with an Olympus BX51 optical microscope. Differential Scanning Calorimetry (DSC) was used to estimate the stored energy and the recrystallization temperature after each ECAP pass.
Innovative Composite HA Scaffold Rapid Prototyping for Bone Reconstruction: An In Vitro Pilot Study
Authors: Lesci Isidoro Giorgio , Ciocca Leonardo , Dozza Barbara , Lucarelli Enrico , Squarzoni Sergio , Donati Davide , Roveri Norberto
Published: September 2013

The ability to control the architecture and strength of a bone tissue engineering scaffold is critical to achieve a harmony between the scaffold and the host tissue. The scaffold attempts to mimic the function of the natural extracellular matrix, providing a temporary template for the growth of target tissues. The study of nanocrystalline calcium phosphate physical-chemical characteristics and, thereafter, the possibility to imitate bone mineral for the development of new advanced biomaterials is constantly growing. Scaffolds should have suitable architecture and strength to serve their intended function. Rapid prototyping (RP) technique is applied to tissue engineering to satisfy this need and to create a scaffold directly from the scanned and digitized image of the defect site. Design and construction of complex structures with different shapes and sizes, at micro and macro scale, with fully interconnected pore structure and appropriate mechanical properties are possible by using RP techniques. In this study we present a new biocompatible hybrid scaffold obtained through two different experimental methods and formed by synthetic biomimetic Hydroxyapatite (HA) nanocrystals with high surface reactivity which synergistically interacts with Poly(e-caprolactone) (PCL) and polylactic acid (PLLA). The aim of this pilot study is to test the adhesion and the proliferation of human mesenchymal stem cells (MSC) on both the scaffolds. MSC growth and distribution was evaluated 24 h and 7 days after in-vitro seeding. The results allowed the conclusion that these scaffolds are biocompatible and allow the colonization and proliferation of MSC, therefore, due to their mechanical properties, they are adequate for bone tissue engineering.
The Functionalization of Remaining Solvent in Polymeric Membrane Pores for Biomedical Applications
Authors: Voicu Stefan  Ioan , Antoniac Iulian , Naftanaila Lacramioara , Nechifor Gheorghe
Published: September 2013

The functionalization of remaining solvent in polymeric membrane pores is presented in this paper leading to new polymeric membrane materials for biomedical applications. Polysulfone membranes were synthesized from aniline by phase inversion and the remaining traces of aniline in membrane pores were transformed by diazotization reaction and coupled with three different organic dyes - Alizarin S, Rhodamine B, and Methyl Orange. The membranes were structurally and morphological characterized and used for different biomedical applications like specific separation of proteins or glucose from synthetic blood solutions.
Stainless Steels with Biocompatible Properties for Medical Devices
Authors: Geantă Victor , Voiculescu Ionelia , Stefanoiu Radu , Rusu Elena Roxana
Published: September 2013

Stainless steels, commercial as well as with special properties, are the principal metallic materials used for medical devices manufacturing. Stainless steels for medical devices should have superior mechanical properties, as: hardness, wear resistance, tensile strength, elongation, fracture toughness, creep resistance etc. This paper aims to present experimental researches regarding the obtaining in vacuum arc remelting device (VAR) of austenitic and martensitic stainless steels and their characterization from microstructure and microhardness point of view.
Chemical-Electric Car as an Undergraduate Student Project
Authors: Wang Qi Chen , Lange Thomas , Choudhary Jay Paul , Koscianski David , Kerr Lei L.
Published: September 2013

A team of undergraduate students at Miami University has conducted design and experiments to build a small Chemical-Electrical (CHEM-E) car with the plan to enter the US National American Institute of Chemical Engineers (AICHE) CHEM-E car competition. The purpose of the CHEM-E car is to enhance undergraduate students experiential learning and get the students prepared for the future need of comprehensively research and analysis of real Chemical-Electric car. This team of undergraduate students has proposed an aluminum-air battery car with design consideration of low cost, durable materials, constrained size of the car, power generation and its stability and car speed.
Study and Analysis on Control Technique of Speed Sensorless in Electric Dynamometer
Authors: Wang Yuan , Wang Shou Cheng , Chen He Nan , Wang Meng
Published: September 2013

Currently the speed estimation methods for control system of speed sensorless are sensitive to changes in the motor stator resistance, and have poor robustness. This paper is proposed a method to obtain the motor speed: by using the stator quadrature axis current and speed equations in permanent magnet synchronous motor, to construct a linear dimensionality reduction Luenberger observer. The notable features of this method are the fast tracking speed and torque response. Finally by applying Matlab simulation and experiments, to verify the effectiveness and feasibility of this system design.
Application of JIT Purchasing on Realizing Zero Inventory Management for Bookuu Website
Authors: Xu Xue Qi , Meng Ling Yan , Qian Xiao Bo
Published: September 2013

This study focuses on the high cancellation rate of purchasing orders at the Bookuu Bookstore website. The discussion starts with some problems associated with the original Bookuu website, especially issues related to order cancellations due to "insufficient inventory". Then, a method of setting up virtual inventory based on the theory of just-in-time purchasing is proposed, which is intended to improve inventory management. In addition, the business process of the Bookuu website is optimized. Finally, we compare and analyze the order cancellation situation before and after implementing the zero-inventory management scheme. Statistical analysis shows that the percentage of the cancelled orders caused by "insufficient inventory" significantly decreased, proving that zero-inventory management of Bookuu.com has been achieved.
Structural Analysis of Factors Influencing Quality Innovation Capability in Manufacturing Enterprises
Authors: Li Wei Hong
Published: September 2013

Through the research on the connotation of quality innovation capability in manufacturing enterprises, 22 factors influencing the quality innovation capability in manufacturing enterprises have been screened out. Based on this, the application of interpretative structural modeling (ISM) has determined the relationship between these factors, establishing the multilevel hierarchical structure model of the main factors affecting the quality innovation capability in manufacturing enterprises, and analyzing the relationships between the five levels of the model and the different roles of each factor that the quality innovation capability of manufacturing enterprises innovation system plays. The results have practical significance for manufacturing enterprises to enhance the quality of innovation capability.
Finite Element Analysis on the Cover of Carding Machine
Authors: Li Song Mei , Chang De Gong , Yang Fu Qin , Fei Zhen Zhong
Published: September 2013

The cover is one of the key components of carding machine and its structural parameters play an important role for the carding quality and yield. In this paper, the force of the designed cover is analyzed when the cover into the carding zone, to obtain the stress and strain distribution of the cover in the whole carding process, based on the finite element analysis software ANSYS Workbench. The research not only examines the stiffness and strength properties of the cover, but also provides a theoretical guidance for the future structure design and parameter optimization.
Dynamic Analysis and Various Mode Strategy Comparisons of the Two-Mode Hybrid Transmission
Authors: Du Ai Min , Xu Da Jin
Published: September 2013

In 2007, a new hybrid electric vehicle was released by General Motor, which is called as Two-mode hybrid electric vehicle. The two-mode hybrid car is famous for its hybrid transmission, which contains two electric motors/generators, three planetary gear sets and four controlled clutches, and allows six different operation modes: two electrically variable transmission modes and four fixed-gear modes [. This paper analyzes the operating condition of the electric machines (Motors/generators) in each mode. And then, it presents three mode selection strategies in order to make a comparison of them.
Intermittent Fault Diagnosis under Extreme Vibration Environment Based on EMD and Neural Network
Authors: Zhou Hui , Liu Guan Jun , Qiu Jing , Lv Ke Hong
Published: September 2013

ntermittent fault under extreme vibration environment is an important cause to affect the function of mechatronics system. A new intermittent fault diagnostic technique based on EMD and neural network methods is proposed in this paper. Firstly, the essential characteristics of intermittent fault under extreme vibration environment are summarized. Then in view of the extreme vibration analysis of electromechanical systems, a new intermittent fault diagnostic technique is put forward by combining EMD and neural network approach. Lastly, the technique is verified by conducting in the heading attitude system of helicopter.
Microstructure and Local Mechanical Properties of Cu-Co Alloys after Severe Plastic Deformation
Authors: Buršík Jiří , Buršíková Vilma , Svoboda Milan , Král Petr , Dvořák Jiří , Sklenička Václav
Published: September 2013

Microstructure of Cu-2wt.%Co alloy after various heat treatment (and hence with various phase constitution) was studied after equal-channel angular pressing (ECAP) using transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD) technique in a scanning electron microscope (SEM). We also focused on local mechanical properties measured across the section perpendicular to the ECAP extrusion direction. Starting from the grain size well above 1mm in the Cu-2wt.%Co solid solution, ECAP subsequently reduces grain size down to the submicron level. A comparison with pure Cu shows that the grain size homogenization is shifted towards higher number of ECAP passes. Fine dispersion of precipitates further slows down the grain refinement and grain size homogenization during ECAP processing. Local mechanical properties measured across the section perpendicular to the ECAP extrusion direction reveal systematic inhomogeneities of deformed microstructure caused by local gradients of temperature and pressure and by the processing geometry itself. This should be considered while characterizing the microstructure by a single EBSD measurement on a small selected area.
Comparison of the Natural Ageing Behaviour of EN AW 6082 and Lead Free EN AW 6023 Aluminium Alloys
Authors: Fujda Martin , Matvija Miloš , Zubko Pavol
Published: September 2013

The effect of solution annealing temperature (550 and 570°C) on the Vickers microhardness of the quenched and naturally aged states of EN AW 6082 and lead free aluminium alloy was investigated. The different chemical composition of analysed alloys did not affect the alloys microhardness after quenching. The total strengthening of both alloys was similar due to the same conjunction of the individual strengthening mechanism of alloys matrix after quenching. The microhardness of EN AW 6082 increased with ageing time increasing according to logarithmic dependence because the increment in alloy microhardness decreased with the increase in ageing time. On the contrary, microhardness of lead-free EN AW 6023 did not increase markedly either after 500 hours natural ageing. This alloy have very slow rate of natural ageing, probably due to suppressed diffusion of alloying elements and clusters and/or GP-zone formation in supersaturated solid solution.
Reduction of Elastic Modulus of Titanium Alloy Ti-6Al-4V by Quenching
Authors: Anisimov Evgeniy , Puchnin Maxim
Published: September 2013

The use of nanoindentation techniques enhances the capabilities of qualitative analysis of elasto-plastic characteristics, especially, estimating mechanical properties of relatively small specimens in their surface layers. The results are in agreement with macromethods, which gather the information over the higher volume of the material. It was confirmed, that hardening of double phase Ti-6Al-4V alloy by quenching from beta temperatures (above beta-transus), reduces the elastic modulus by about 8 % due to increased ratio of low-modulus beta phase from 8 to 34 %.
Mechanical Properties of Interface of Heterogeneous Diffusion Welds of Titanium and Austenitic Steel
Authors: Kolařík Ladislav , Kolaříková Marie , Vondrouš Petr
Published: September 2013

Titanium is material which is used in many areas of human activity. Therefore it is necessary to join it with other material. It is very difficult to welding Ti with other metals by conventional fusion welding methods. There exist special joining technologies of heterogeneous materials which is possible to use. This is usually a joining of materials in the solid state, as diffusion welding, friction welding or explosion welding. This contribution deals with diffusion welding of titanium alloy Ti6Al4V and stainless austenitic steel 1.4301. There are described mechanical properties (as is reduced modulus Er and indentation hardness HIT) and changes of chemical composition of join due to diffusion of elements.
The Resistance Tests of Glass-Cement Plates in High Temperatures
Authors: Kostelecká Michaela , Vokáč Miroslav , Dobiáš Daniel
Published: September 2013

The glass-cement plates have made great progress today. They extend the possibilities of technical requirements in solutions of complex structures. The higher aesthetic requirements are available with the plates and in another point of view they contribute significantly to economic aspect in construction. The article describes the tests of high temperatures resistances of glass-cement plates. The first part is focused on determining the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 ° C in endurance at the highest temperature level for 24 hours. The results will be compared with values obtained for the reference samples. The bending strength was performed according to the norm ČSN EN 1170-4 Precast concrete products - Test method for glass-fibre reinforced cement - Part 4: Measuring bending strength, "Simplified bending test" method. The mean strength in bending of reference samples was equal to 11.3 MPa. The strength is decreasing with temperature of firing and dependence is very closed to linear relationship with slope approx. 1.87 MPa per 100 °C. Furthermore, the thermal dilatometric analysis was performed on the plates in the temperatures till 540 °C in the second part.
Measurement of Local Initiation, Early Growth and Retardation of Physically Short Fatigue Cracks Using Amended DCPD Method
Authors: Černý Ivo
Published: September 2013

Different experimental methods are being used in laboratories for automatic measurement of fatigue crack growth rates and threshold values. Such data belong to mechanical properties essential for an assessment of residual life of components and structures containing cracks of length more than several millimetres. However, if the material contains small crack-like defects like inclusions or pores, knowledge about local resistance against fatigue growth of physically short cracks becomes very important. Damage mechanisms are even more complicated in case of a presence of subsurface residual stress field, e.g. due to technological effects. Experimental difficulties connected with investigation of short fatigue crack growth (FCG) can be reduced in case of use of automatic indirect methods. The aim of the work described in this paper was to explore possibilities and limits of the use of DCPD (direct current potential drop) method for physically short crack measurement and to use the optimised method for an evaluation of local damage process of initiation and early growth of short fatigue crack in residual stress field induced by shot peening.
Ionizing Radiation Effect on PMMA Measured by Microhardness
Authors: Manas David , Ovsik Martin , Manas Miroslav , Stanek Michal , Javorik Jakub , Bednarik Martin , Kratky Petr
Published: September 2013

The experimental study deals with the effect of modification of the surface layer by irradiation cross-linking on the mechanical properties of the Poly (methyl methacrylate) - PMMA tested using the instrumented microhardness test. The surface layer of PMMA specimen made by injection technology was modified by irradiation cross-linking using beta irradiation, which significantly influences mechanical properties of the surface layer. Compared to the heat and chemical-heat treatment of metal materials (e.g. hardening, nitridation, case hardening), cross-linking in polymers affects the surfaces in micro layers. These mechanical changes of the surface layer are observed in the instrumented microhardness test. Our research confirms the comparable properties of surface layer of irradiated PMMA with highly efficient polymers. The subject of this research is the influence of irradiation dosage on the changes of mechanical properties of PMMA.