bluuebunny/crossref_metadata_2025 huggingface dataset:
II. Characterizations of Alginate-Chitosan Hydrogel for Wound Dressing Application
Authors: Xing Nan , Tian Feng , Yang Jian , Li Yu Kun
Published: March 2012

The aim of this study is to evaluate the characterizations of alginate-chitosan hydrogel for wound dressing application. The influence of alginate concentrations (1%, 2%, 3% and 4% (w/v)) was investigated. An increase in alginate concentration leads to a decrease in swelling capacity but an increase in holding capacity. All the hydrogels exhibited above 80% water holding abilities. The hydrogel leach outs were nontoxic to the cells, as confirmed by MTT assay. Taken together these results point out that alginate-chitosan polyelectrolyte hydrogel can be considered for wound dressing applications.
Magnetization Evolution with the Doping Element in Double Perovskite
Authors: Zhang Qin , Wang Qing , Yuan Suo Jia
Published: March 2012

Double perovskite (Sr1.85Ln0.15)FeMoO6 (Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure investigation shows that all the samples are of single phase and belong to the I4/m space group. Saturation magnetization of the compounds at 5 K cannot be explained simply by ferrimagnetic model (FIM). However, the saturation magnetization at 100 K of the doped compounds exhibits a linear decrease with the increase of the anti-site defect concentration. Comparison of the saturation magnetization of the compounds at 5 K and 100 K suggests that at 5 K the magnetic moments of Ce, Pr, Nd and Sm align parallel with that of Fe, while the magnetic moment of Eu is anti-parallel with that of Fe.
Application of Laser Heat Treatment Process on the Surface Treatment of Pipe Threaded
Authors: Liu Jian Ying , Liu Jun
Published: March 2012

The oil pipe is the special pipe of oil wells that is put into the wells to produce fluid or inject liquid. Because the pipe was put under the ground deeply, the higher strength and sealing are request. Therefore, the accuracy and strength of the connecting thread are required. Moreover, because of the oil wells need to be repaired frequently when they work, the shackle times are the important factor of the production life of the oil pipe. The development of the oil pipe is always blocked by the phenomenon of oil's gluing. As the remarkable feature of the Laser heat treatment process technology and the increasing of productions of the domestic laser devices, the laser heat treatment process technology was applied to the surface of the oil threaded to improve the integrated mechanical properties of oil pipe products and to extend its work life.
Fracture Analysis near Interface Crack Tip for Mode I of Orthotropic Bi-Materials
Authors: Dong An Qiang , Yang Wei Yang , Li Jun Lin
Published: March 2012

The mechanical behaviors near interface crack tip for mode I of double dissimilar orthotropic composites are studied. By translating governing equations into generalized biharmonic equations, the stress functions containing two stress singularity exponents are found with the help of a complex function method. Based on the boundary conditions, two systems of non-homogeneous linear equations are obtained. Through solving these systems two real stress singularity exponents are determined under appropriate condition of bimaterial engineering parameters. By the uniqueness theorem of limit,both the theoretical formulae of stress intensity factors and analytic solutions of stress field and displacement field near interface crack tip are deduced.
Facile Synthesis and Enhanced Photocatalysis of Sm Doped TiO2
Authors: Gao Hong Tao , Liu Wen Chao , Liu Guang Jun
Published: March 2012

Sm doped nanocrystalline TiO2 powers were prepared by ultrasonic assisted sol-gel synthesis. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-visible diffuse reflectance spectra (DRS), respectively. Both of undoped TiO2 and Sm-TiO2 samples exclusively consist of primary anatase crystallites, which further form spherical aggregates with average diameters ranging from 11 to 19 nm. The photocatalytic activity of Sm-TiO2 was investigated on the photocatalytic degradation of methyl orange (MO) aqueous solution under UV visible light irradiation. Sm doping improves effectively the photocatalytic activity under UV light irradiation with an optimal doping concentration of 0.5%. The photocatalytic mechanisms of Sm-TiO2 catalysts were tentatively discussed
Drilling Simulation on Carbon Fiber Reinforced Plastics and Aluminum Laminated Composite
Authors: Li Bo , Liu Shu Nuan , Tian Xi Tian , Gao Fei , Zhang Zhen Ming
Published: March 2012

In order to study the process of drilling carbon fiber reinforced plastics and aluminum alloy laminated composite, a simulation on drilling is conducted by using FEM analysis software ABAQUS, the finite element model of carbon fiber composite material finite element model is established. The dynamic simulation of the drilling process of carbon fiber reinforced plastics is carry on, which based on the elastic-plastic theory of material deformation and the thermal coupling theory, obtaining continuous drilling force and torque data. The influence of material and parameters on drilling and drilling technology on drilling process are deeply analyzed, obtain relationship about material and feed rate and drilling force and torque. The result of the research provides the support for further study of high speed drilling mechanism of carbon fiber reinforced plastics.
Flame Retardancy of Lanthanum Phosphinate in Combination with Intumescen Flame-Retardant in Polypropylene
Authors: Liu Cong
Published: March 2012

The flame-retardant of Lanthanum phenylphosphinate(LaPi) was prepared and its combination with intumescent flame retardant (IFR) in polypropylene (PP) was analysed using thermogravimetric analysis (TGA), limiting oxygen index (LOI) and the UL-94 test. Compared with using IFR alone, using the combination of LaPi and IFR gained the better classification in the UL 94 test thanks to the combination of the different mechanisms. When 20 wt% loading of flame retardant of LaPi and IFR, a halogen-free V-0 PP material was achieved with a LOI of 31%.
Preparation and Research of Short Carbon Fibers Network Structure Antistatic Composites
Authors: Zhang Shan , Wang Cheng Guo , Yuan Hua , Lin Xue
Published: March 2012

A kind of antistatic composites were successfully prepared in large scale by the spraying construction technology, based on fluorocarbon coating, containing short carbon fibers (SCFs) conductive filler. The influences of resin viscosity, pigments and fillers on the dispersion of SCFs in fluorocarbon coating were studied. The degree of SCFs dispersion was charactered by dispersion coefficient. The results show that the higher viscosity redounds to the dispersion of SCFs in fluorocarbon matrix, and the suitable spraying viscosity should be controlled at 60s~100s (T-4 Viscosity cup); the discontinuous distribution of pigments and fillers plays a positive role to the dispersion of SCFs and hinders the reaggregation of SCFs.
Preparation and Characterization of Attapulgite Modified by KH-570 for Formaldehyde Adsorption
Authors: Hu Tao , Yang Yong , Xia Jian Wen
Published: March 2012

Modification of attapulgite by KH-570 for formaldehyde adsorption and characterization of the resulting sorbents by SEM, BET, FT-IR and TG-DSC were conducted, as well as the test of the breakthrough curves of formaldehyde dynamic adsorption. The results show that KH570 was grafted with the surface silanol group of attapulgite. The adsorption capacity of attapulgite for formaldehyde was improved significantly by KH-570, which has a certain utility to remove the formaldehyde gas in the air.
Research on Metal-Rubber Composite Damping Steel Plate Application in Acoustic Bridge for Double Cylindrical Shell
Authors: Xia Qi Qiang , Chen Zhi Jian , Gong Jie , Zhang Li Jun
Published: March 2012

In order to reduce the low-frequency line spectrum of double cylindrical shell, the research was done to apply composite damping steel plate in acoustic bridge between two shells. By suppressing vibration energy transmission along acoustic bridge, two types of composite damping rib-plate were designed with the resistance increasing technology based on the principle of damping vibration attenuation. Then the vibro-acoustic characteristics of double cylindrical shell were analyzed through numerical calculations, considering original and improved acoustic bridge. The results shows that: composite damping steel plate applying in acoustic bridge can reduce sound radiation of double cylindrical shell effectively, properly increasing damping between composite plates is beneficial for vibration and noise reduction. These research results could be a reference for submarine acoustic stealth design.
Study on Automatic Calibration System of Multi-Layered Laminated Thin Film Thermocouple Cutting Temperature Sensor
Authors: Wang Ya Nan , Li Dong Ming , Cui Yun Xian , Ibrahim Rasidi
Published: March 2012

In cutting temperature survey, in order to reflect the temperature change of cutting area accurately, the cutting tool sensor should have good technical characteristic. In this paper, one kind of automatic calibration system has been developed which could be used to investigate the technical characteristic of the multi-layered laminated thin film thermocouple cutting temperature sensor, this system selects Platinum-chip temperature sensor (concrete model: EN60751) as the standard temperature sensor, uses the AD524 precise amplifier chip building amplifying circuit and compiles the software with LabVIEW. This paper intends to investigate the static characteristic of the multi-layered laminated thin film thermocouple cutting temperature sensor system, the result shows that the Seebeck coefficient is 66.9 μV/°C, and the nonlinear error of fitting is smaller than 0.32%. This research has paved the way for future studying of thin film thermocouple cutting temperature sensor technology characteristic.
Research Progress of New Methods for Toughening Epoxy Resin
Authors: Guo Li Ying , Wang Li Yan , Su Xin
Published: March 2012

The epoxy is a thermosetting resin, for the lack of toughness after cured ,a brief introduction of epoxy resin toughening technology research progress, detailed in the recent years a number of toughening epoxy resins new methods, including toughened thermoplastic resin, IPN toughening, core-shell particle toughening, thermotropic liquid crystalline toughness, rigid polymer toughening, nano-particle toughening and so on. At last, the paper provided an overview of the progress of epoxy toughening modification technology and its future prospects.
Review of Hygrothermal Effects on Carbon Fiber-Reinforced Composite Materials
Authors: Jin Ping , Wang De , Tan Xiao Ming
Published: March 2012

This paper presents a review of the effects of hygrothermal environment on carbon fiber-reinforced composite materials. A brief summary of the hygrothermal phenomenon and hygrothermal mechanism of CFRP is followed by a detailed review of hygrothermal effects on the performance of the three components of CFRP. In the last, the main problems existing in research process nowadays and its tendency have been proposed.
Study on the Factors Influencing Plating Coat Thickness in Ultrasonic-Aided Hot-Dip Aluminizing Facing Remanufacturing
Authors: Niu Zong Wei , Huang Xue Mei , Zhang Jia You , Liu Hong Fu , Li Li
Published: March 2012

An aluminum layer can be gotten on the worn-out work piece surface through ultrasonic-aided hot-dip and converted into alumina layer having wear-resistance performance though micro arc oxidation which can realize remanufacturing. The key technology of hot-dip aluminizing phase in above remanufacturing process is controlling the plating coat thickness. The influences of withdrawing speed, hot-dip temperature and hot-dip time on the plating coat thickness are analyzed in this paper.
Synthesis of a Novel Photochromic Fluorescence Switching Diarylethene for Optical Recording Storage
Authors: Wang Tao Feng , Liu Gang , Liu Wei Jun
Published: March 2012

A new unsymmetrical photochromic diarylethene bearing a benzothiophene aryl unit, 1-[2-methyl-5-(1,3-dithiolpentane)-3-thienyl]-2-[2-methyl-3-benzothiophenyl]perfluoroyclopentene has been synthesized, and its photochromic, fluorescence and optical recording strorage properties were investigated. The compound exhibited pronounced photochromic and clear fluorescence switching properties upon alternating irradiation with UV and visible light; the colorless open form with fluorescence character could be regenerated by irradiation with visible light. In terms of potential use for optical storage and readout, this compound displays fluorescence discrimination between its open and closed form. This fluorescence switching could be the basis of a remote control nondestructive readout method.
Study on Rupture Curing and Monitoring of Shaft Lining in the Special Stratum
Authors: He Peng Li , Guo Li
Published: March 2012

The technology for curing rapture and strain monitoring of coal mine shaft in special stratum is discussed in this paper. The mine shaft lining in the deep and thick overburden is put a vertical additional, which is caused by the draining consolidation settlement of bottom aquifer. When the force together with others forces is more than the ultimate strength of concrete lining, the shaft lining will be lead to fracture. In order to treat the broken shaft lining, the integrated management method of dense shaft circles, the grouting, and loop relieving-pressure grooves was taken. The monitoring information of the remote shaft lining strain automatic monitoring system can be used to predict and evaluate the safety state of the shaft lining. The suggested mechanism and technology are able to prevent and cure shaft lining rapture in other similar mine. The treatment attained to the ideal effect and the method has an important reference value for the prevention and curing of shaft lining rupture in the same strata.
The Adhesion Testing and Analysis for NiCr/NiSi Thin-Film Sensor
Authors: Zheng Xiao Feng , Zeng Qi Yong , Li Zhu , Jiang Li Zheng , Chen Feng
Published: March 2012

By the method of orthogonal experiment, with different sputtering power, sputtering pressure, sputtering time and substrate bias, 9 NiCr-NiSi thin-film thermocouples with different properties were prepared on the rake face of different cutting tools. With WS-2005 coating adhesion automatic scratch tester, the adhesion between the thin-film and the cutting tools were tested, and the test results was analyzed by range analysis. Analysis results show that, among four sputtering factors, substrate bias is the most important factor which influenced the thin-film adhesion. In a certain range, increasing the substrate negative bias voltage value can enhance the adhesion of thin-film. Subsequently, the range analysis result was verified by test. The best set of parameters was selected among all of the orthogonal test results, with other parameters unchanged except substrate negative bias, which was increased to -110V.And that, the adhesion value of NiCr and NiSi film was increased by 3.2N and 1.5N around individually.
The Studies on Photolysis of Dioxins from MSW Ash by TiO2 Thin Film Codoped Co and N
Authors: Wang Lan , Ren Jun Ling , Chang Bing
Published: March 2012

Co\N codoped mesoporous TiO2 thin films that adhered to the glass slides were prepared with normal temperature complexation method by using tetrabutyl titanate(TBT) , triethylamine(TEA), cobalt dichloride hexahydrate．The XRD patterns of the samples of the thin films indicated that the sample appeared sharp titanium ore and rutile characteristic peaks and characteristic peaks became wide．And the photocatalytic degradation study of dioxins from MSW ash had been carried out. The result showed that the mesoporous TiO2 thin films Co\N codoped had high photocatalytic efficiency and was in favor of the regeneration and reuse.
The Study on Microstructure and Thermal Expansion Property of SiCp/Al-30Si Composite Material Prepared by Hot-Pressing
Authors: Wang Ai Qin , Fang Ming , Xie Jing Pei , Ni Zeng Lei , Zhang Li Jun
Published: March 2012

The SiCp/Al-30Si composite material was prepared by hot-pressing. The microstructure was characterized by means of optical microscope and SEM, the thermal expansion performance was tested by PYC-Ⅲ Thermal Expansion Coefficient Tester. It was researched that the influence of SiC particle size and manufacture technology on the microstructure and thermal expansion coefficient. Results show that shortening soaking time decreases the number and the size of the nascent and precipitating Si particles, enlarges the CTE of the composite; lager pressure is beneficial to reduce the CTE of the composite, and the larger the pressure is, the more compact microstructure is and the less number of holes are. Thermal expansion performance of the composite was influenced by SiC particle size, distribution of matrix phase, trait of interface combination and the holes.
Developing and Research on Motion Controller Based on CPLD and MCU
Authors: Han Jun , Chang Rui Li
Published: March 2012

Open Computer Numerical Control system (Open CNC) based on PC and the Windows operating system has been a major developing direction and a research focus of the current numerical control technology. At present, there have been all kinds of the Open CNC systems with high-speed and precision servo control boards, but they are too expensive. Therefore, developing an economical and practical motion controller is great significant for middle and small numerical control system
Study of Compound Fuzzy-PID System for Engine Speed Control of PHEV
Authors: Zang Huai Gang , Han Yan Long , Niu Yan Xia
Published: March 2012

This paper is a research about the speed adjustment of Parallel Hybrid Electric Vehicle engine under different operating conditions. It seems that the traditional PID controller is powerless owing to nonlinear and time-varying of the engine system. This paper studies coordinated control problems of the engine by using compound fuzzy-PID control method, which greatly reduces the difficulty of the nonlinear system control and improves robustness and real-time of the control system. And dynamic model of PHEV engine is established by using kinetic equations in this paper. Compared with traditional PID and fuzzy system, it proves that compound fuzzy-PID system has a better control performance, which can meet the requirements of quick start of the engine and speed regulation under the three kinds of adjustments of engine idle speed, vehicle acceleration and speed regulation in the process of the drive mode switching.
The Analysis Method of Highline Cable of Alongside Replenishment System Based on Suspended Cable Theory
Authors: Wei Kai , Zhang Liang Xin , Ren Ai Di
Published: March 2012

According to mechanical characteristics of highline cable of alongside replenishment system at sea, two mathematical methods for static analysis of the highline cable under its own weight are investigated: catenary method, which is the exact solution, and parabolic method, which is the approximate solution but simpler to calculate. A model consisting of two sections of catenary is established for the analysis of the highline cable under a concentrated load. The expressions of the length and the tension of the highline cable are derived, and the result of each section is obtained.
The Application of RBF Neural Networks in Curve Fitting
Authors: Sheng Zhong Biao , Tong Xiao Rong
Published: March 2012

Three means to realize function approach such as the interpolation approach, fitting approach as well as the neural network approach are discussed based on Matlab to meet the demand of data processing in engineering application. Based on basic principle of introduction, realization methods to non-linear are researched using interpolation function and fitting function in Matlab with example. It mainly studies the RBF neural networks and the training method. RBF neural network to proximate nonlinear function is designed and the desired effect is achieved through the training and simulation of network. As is shown from the simulation results, RBF network has strong nonlinear processing and approximating features, and RBF network model has the characteristics of high precision, fast learning speed for the prediction.
The Modification Design of Road Traffic Information Mobile Monitoring Vehicle
Authors: Qi Ying Jie , Wang Qiang
Published: March 2012

At present, video monitoring equipments on highways in china are mostly used in a fixed position of the main roads, and the wired mode is generally used to transmit data. The purpose to improve the monitoring areas can be achieved by increasing the monitoring equipments and other means, but the cost of these methods are too high and the data transmission is limited by area, greatly restricting the large-scale application of those traffic monitoring equipments. In this paper, in order to achieve the function of road traffic information mobile monitoring, it completed the modification design of road traffic information mobile monitoring vehicle by use of CAD/CAE computer-aided designing tools. In this process, Jinbei SY6480 minibus was selected as the modification object, and the new re-layout in the car was implemented, and the lifting mechanism and vehicle wind-resistant design on the information collection equipment were especially included. Finally the three-dimensional modeling and finite element analysis were advanced by use of Pro/E and ANSYS software, ensuring the rationality of design. The vehicle designed by this paper can ensure that the information collection equipment achieve the intelligent monitoring function safely, stably and quickly.
The Mathematical Analysis of Underwater Vehicle Control System
Authors: Tang Zhi Jie , Shen Jia Li , He Qing Bo , Wang Shu Ai , Luo Jun
Published: March 2012

In order to ensure that submersible has good performance of control , the kinematic model of underwater vehicle must be fairly accurate. At the same time, the accuracy of the kinematic model also is affected by hydrodynamic coefficients. Taking the underwater vehicle model as research object, the formula of the acceleration coefficient was deduced and hydrodynamic coefficients were calculated with the combination of theoretical and experiential formulas. Besides,the depth transfer function and heading transfer function were obtained. At last, we simulated the system and calibrated with PID
The Research and Design on the Electrical Control System of TG200 Bridge Machine
Authors: Liu Jin Zhi , Zhi Xiao Hui , Ma Li Ming , Li Shen Shan
Published: March 2012

In this paper the structural characteristics of TG200 bridge machine was introduced, the overall design scheme of control system was determined and the electrical control system, which was mainly made up of PLC, inverter, remote controller and human-machine interface, was designed. Industrial test proved that the control system is stable and easy to operate, and that it can provide an important safeguard for the long-term safe operation of the bridge machine.
Design Based on Multi-Channel Power Acquisition and Data Teletransmission System of MSP430 Simulating SPI Interface and CS5460A Communication
Authors: Zhou Wen Hua , Chen Xiao Long
Published: March 2012

Real-time acquisition of multi-channel power and data teletransmission is the most frequent important problems in power system to be solved perfectly. SPI, a synchronous serial interface, can connect multiple microcontrollers and all kinds of input-output devices with SPI interface which send and receive independent. However, most microcontrollers usually only with a single SPI interface which seems powerless when it communicates with many chip in need of the way of SPI. This paper taking the three-phase power acquisition and data teletransmission design of power system as an example lays special stress on introducing a design method to well solve the above problems based on the realization of three-phase power collection through MSP430 simulating SPI interface communicating with multi-block CS5460A. The design is simple and low-cost. Moreover, it has a broad prospect of application in the fields of multi-channel data measurement and acquisition and teletransmission communication and so on.
Study of Shock Control of Gear-Shifting in Automatic Transmission
Authors: Chen Xiang , Li Guo Fang , Zhang Lin Yan , Liu Shuang
Published: March 2012

A new smooth shifting control is worked out in response to problems existed in gear-shift control of the AG4 automatic transmission, and a new pattern of oil pressure change for the engaging elements during the transition stage is formulated. Dynamic motion equations for the AG4 automatic transmission are established using simulated lever system. The simulation test is done of the 2nd-3rd (3rd-2nd) gear-shift phase in AG4 automatic transmission by means of MATLAB/Simulink software. The result of which shows the change in amplitude of the output shaft angular acceleration and that of the degree of jerk are noticeably reduced when applying the new oil pressure pattern to control the process in the AG4 automatic transmission. Therefore, the smooth shifting control is achieved by reducing the shock subjected during gear-shift, and thus the gear-shift process is greatly improved.
Multi-Dimension and Structure Element Edge-Detection Based on Mathematical Morphology
Authors: Liang Ying Bo , Zhang Li Hong
Published: March 2012

A novel multi-dimension and structure element edge-detection based on mathematical morphology is presented to resolve blur problem of classical morphology when detecting an edge to reduce the noise but hard to preserve the details and edge information of the original image effectively. First,pretreatment of the image are completed by close-open operation to eliminate noise; second,do close operation to smooth image,in the end,using the operation of morphological gradient for smooting image,the ideal image edge under the environment of existing noise is obtained,and it is applied to detect the edges of welding pore images. The experimental results show that it is compared with classical Sobel operators,Canny operators and traditional edge detection algorithm, the proposed algorithm has the following distinguished advantages:accuracy of edges detected, a clear outline of the image, and can preserve more image details as well, and insensitive to noise.
Queueing Analysis of Spectrum Trading for Wireless Cognitive Radio Networks
Authors: Liu Li Xia , Hu Gang , Huang Zhen , Peng Yu Xing
Published: March 2012

Spectrum trading is an important approach for the secondary users (SU, the unlicensed user) to share the spectrum resource with the primary users (PU, the licensed user). Such economic method can improve not only the efficiency but also the quality of spectrum sharing. For getting the most profit from the spectrum trading, we considered a spectrum trading model based on queueing theory. We analyzed the relationship between the spectrum server and the spectrum demander and discussed the problem of server uncertainty. Simulation results demonstrated the analysis results in terms of the idle probability and average queue size.
Analytical Solutions of the Boltzmann Transformation Equation
Authors: Okino T. , Shimozaki T. , Fukuda R. , Cho Hiroki
Published: March 2012

The so-called continuity equation derived by Fick is one of the most fundamental and extremely important equations in physics and/or in materials science. As is well known, this partial differential equation is also called the diffusion equation or the heat conduction equation and is applicable to physical phenomena of the conservation system. Incorporating the parabolic law relevant to a random movement into it, Boltzmann obtained the ordinary differential equation (B-equation). Matano then applied the B-equation to the analysis of the nonlinear problem for the interdiffusion experiment. The empirical Boltzmann-Matano (B-M) method has been successful in the metallurgical field. However, the nonlinear B-equation was not mathematically solved for a long time. Recently, the analytical solutions of the B-equation were obtained in accordance with the results of the B-M method. In the present study, an applicable limitation of the B-equation to the interdiffusion problems is investigated from a mathematical point of view.
TiAl3 Formation in the Titanium-Aluminum Diffusion Couple
Authors: Mirjalili Mostafa , Soltanieh Mansour , Matsuura Kiyotaka , Ohno Munekazu
Published: March 2012

Pure titanium and aluminum sheets were used to prepare titanium-aluminum diffusion couples. The diffusion couples were heated to temperatures 550, 575, 600, 625, 640, 650 and 700°C. SEM observations of the titanium-aluminum interface and EPMA results revealed that a TiAl3intermetallic layer has formed and thickened between the layers. Grain boundaries of the TiAl3compound, which were revealed by back-scattered electron imaging, indicated a size distribution across the layer. Finer grains which were located close to the titanium showed that TiAl3has nucleated at the Ti-TiAl3interface. Thus, the former grains which had formed close to the aluminum-rich side have grown and coarsened during annealing at high temperatures. Grain coarsening of TiAl3decreased the kinetics of the layer thickening.
EPD of Phosphors for Display and Solid State Lighting Technologies
Authors: Choi Jae Ik , Sluzky Esther , Anc Maria , Piquette Alan , Hannah Mark E. , Mishra K.C. , McKittrick Joanna , Talbot Jan B.
Published: March 2012

Electrophoretic deposition (EPD) has been used for phosphor screening for a variety of emissive information displays and more recently, for solid state lighting. EPD is well suited to deposit the fine (nanometer to micrometer diameter) phosphor particles needed for high resolution displays. The fundamentals of the EPD process in an isopropanol (IPA) bath have been characterized by the dissociation behavior of nitrate salts in IPA, measurement of the effects of pH and nitrate salt concentration on the zeta potential of the particles, studying of the processing conditions and modeling of the deposition rates. The electrochemical precipitation reactions form an adhesive agent for the particles and the adhesion strength can be enhanced by various methods to meet the requirements of these technologies.
Characterization of a Ceramic Powder Surface by Contact Angle Measurements and Infrared Spectroscopy
Authors: Neirinck Bram , Soccol Dimitri , Fransaer Jan , Van der Biest Omer , Vleugels Jef
Published: March 2012

The surface chemistry of a suspended particle greatly affects it behavior during electrophoretic deposition. The type and amount of surface groups determines whether the particles can be charged by interaction with the solvent. Furthermore, it is suspected that the surface chemistry plays a prominent role in the mechanisms governing the actual deposition of the particles. In the present work the surface chemistry of as-received and surface modified alumina powder is characterized by means of contact angle measurements and Diffuse Reflectance Infrared Fourier Transform spectroscopy. The wetting is measured using a modified Washburn method which yields quantitative contact angle values. The acid-base and dispersive surface energy components are calculated from these values using the surface tension component theory. Infrared spectroscopy was used to compare the surface groups of the treated and untreated powders and confirm the trends in surface properties as calculated from the contact angles.
Triethanolamine as an Additive in the Electrophoretic Deposition of TiTe3O8 Thick Films
Authors: Su Xin Ming , Wu Ai Ying , Vilarinho Paula M.
Published: March 2012

A successful electrophoretic deposition (EPD) markedly depends on the stability of the suspension. In this study the role of Triethanolamine (TEA) as a stabilizer in EPD of thick films of TiTe3O8 is presented. TiTe3O8 powders were synthesized via a conventional solid-state-reaction method and dispersed in acetone with and without TEA. The stability of the suspensions was addressed by zeta-potential, UV light and FTIR measurements. The specific adsorption of TEA to TiTe3O8 particles results in a high zeta potential and improved stability of the suspensions, allowing the preparation of high quality TiTe3O8 thick films on Pt coated Si substrates. TiTe3O8 films sintered at 700 °C are dense and homogeneous.
Direct Numerical Simulations of Electrophoretic Deposition of Charged Colloidal Suspensions
Authors: Park Jae Sung , Saintillan David
Published: March 2012

Motivated by applications in the field of nanomanufacturing, we perform large-scale numerical simulations of the electrophoretic deposition of suspensions of charged colloids in an electrolyte. A simulation method is developed to model the full deposition process that captures linear electrophoresis, dipolar interactions, van-der-Waals forces, steric interactions, Brownian motion, as well as electric and hydrodynamic interactions with the electrodes. Using a fast algorithm, suspensions of up to 5,000 particles are simulated, and results are reported for the final deposit microstructure as a function of field strength. The simulation results demonstrate that regular crystalline colloidal assemblies are obtained at low field strengths and volume fractions, while more random structures with frequent defects are formed in stronger fields and at higher volume fractions, in agreement with recent deposition experiments.
Current Measurements as a Direct Diagnostic for Sub-Monolayer Growth of Nanoparticle Films in Non-Polar Electrophoretic Deposition
Authors: Krejci Alex J. , Gonzalo-Juan Isabel , Dickerson James H.
Published: March 2012

Electrophoretic current densities and nanoparticle densities were measured during and after the electrophoretic deposition of iron oxide nanoparticles and were compared to infer the relationship between the quantity of deposited nanoparticles and the measured current. This information led to an assessment of the primary contributors to the measured current during non-polar solvent-based electrophoretic deposition. Such information was employed to monitor and to control sub-monolayer growth of nanoparticle films. Subsequently, the average charge magnitude of each suspended colloidal nanoparticle was calculated to be ±3.2 ± 0.3 electron charges.
A Controlled Colloidal Destabilization Approach for the Electrophoretic Deposition (EPD) from Cobalt Ferrite and Magnetite Nanoparticles Suspensions in Diethylene Glycol
Authors: Baldisserri Carlo , Gardini Davide , Galassi Carmen
Published: March 2012

Cobalt ferrite (CoFe2O4) and magnetite (Fe3O4) nanoparticles suspensions in diethylene glycol were tested as candidate systems for the EPD of CoFe2O4 and Fe3O4. It was found that despite the high stability and high zeta potential of such suspensions and the occurrence of mass transport at the electrode, they are not viable systems for EPD, due to coagulation failure. However, dilution of both suspensions with ethanol caused film coagulation at electric field between 20 and 60 V cm-1. Combinations of electric field and DEG volume fraction in ethanol/suspension mixtures that allow EPD to take place are detailed, and a description of the outcome of EPD trials is provided. A qualitative discussion of the causes of film consolidation in the presence of ethanol is presented.
Hybrid Electrophoretic Deposition with Anodization Process for Superhydrophilic Surfaces to Enhance Critical Heat Flux
Authors: Joung Young Soo , Buie Cullen R.
Published: March 2012

Superhydrophilic surfaces with hydrophobic layers were successfully produced in order to enhance critical heat flux (CHF) and reduce boiling inception temperatures (BIT). The novel surfaces were fabricated by a hybrid electrophoretic deposition (EPD) method coupled with a break down anodization (BDA) process. With the BDA process, microporous superhydrophilic surfaces were created on titanium substrates. Subsequently, nanoporous hydrophobic layers were deposited with EPD on the superhydrophilic surfaces. The hydrophobic layers provide numerous nucleation sites, lowering BIT while the superhydrophilic layers prevent film boiling, resulting in increased CHF. The resulting surfaces exhibit higher CHF with lower BIT than untreated titanium surfaces .
Theoretical Model of a Multi-Layered Polymer Coated Steel-Strip Ironing Process Using a Neural Network
Authors: Sellés M.A. , Schmid S.R. , Sánchez-Caballero S. , Pérez-Bernabeu E. , Reig M.J. , Segui V.J.
Published: March 2012

An alternative to the traditional can manufacturing process is to use plastic laminated rolled steels as base stocks. This material consist of pre-heated steel coils that are sandwiched between one or two sheets of polymer. The heated sheets are then immediately quenched, which yields a strong bond between the layers. Such polymer-coated steels were investigated by Jaworski [1, and Sellés [, and found to be suitable for ironing with carefully controlled conditions. A novel multi-layer polymer coated steel has been developed for container applications. This material presents an interesting extension to previous research on polymer laminated steel in ironing, and offers several advantages over the previous material (Sellés [). This document shows a modelization for the ironing process (the most crucial step in can manufacturing) done by using a neural network.
Two FEM Thermal Models for Shallow and Deep Grinding
Authors: Ortega N. , Pombo Inigo , Alonso U. , Sánchez J.A. , Izquierdo B. , Plaza Soraya
Published: March 2012

Grinding is a stochastic process applied in the last stages of the manufacturing cycle. In last decades, grinding research has focused on prediction of thermal damage on ground workpiece since it is of considerable importance from both research and industrial perspectives. A number of numerical and analytical thermal models have been carried out so far. However, new grinding processes such as peel grinding, creep feed grinding and others such as plongee grinding need new models which consider the effect of higher depth of cuts, but there is no information about the minimum depth of cut to consider the elimination of grounded material in FEM models. This article establishes the frontier from which the removed ground material should be physically eliminated to obtain an accurate FEM thermal model. Results show valuable information to decide which kind of model (with or without element elimination) is enough accurate for their purpose and application.
Effective Utilization of Rapid Prototyping Technology
Authors: Novakova-Marcincinova L. , Fecova V. , Novak-Marcincin J. , Janak M. , Barna J.
Published: March 2012

Technology of Rapid Prototyping (RP) presents the technique that leads to quick manufacturing of real model using the scaling with support of three-dimensional software solution running in computer environment (CAD). First RP technique, Stereolithography, was developed by 3D Systems of Valencia, CA, USA. The company was founded in 1986, and since then, a number of different RP techniques have become available. Article deals with basic characteristics and problems in area of technology of Rapid Prototyping with focus to Fused Deposition Modeling. It brings in the project of experimental gearbox design and its manufacturing with application of Rapid Prototyping technology. The work was realized by students and employees of Faculty of Manufacturing Technologies in Presov, Slovakia. Model with four gears was realized together with its gear changing mechanism. Production of gearbox was connected with problems arising from size of individual parts and included also the realization of final gearbox assembly.
Effect of Rapid Solidification on the Structure and Mechanical Properties of AZ91 Magnesium Alloy
Authors: Tokarski Tomasz
Published: March 2012

The present paper reports an experimental investigation of rapid solidification (RS) influence on the structure and mechanical properties of commercial AZ91 magnesium alloy. In order to obtain RS material melt spinning process was applied in protective atmosphere, resulting in formation of 50 to 100 μm thickness RS ribbons. Application of plastic consolidation (PC) by hot extrusion to the highly fragmented magnesium strips allowed to obtain high bulk strength material. It was found that yield strength (YS) and ultimate tensile strength (UTS) of RS+PC material with comparison to the cast and extruded samples were increased from 220 MPa to 303 MPa and from 287 MPa to 385 MPa, respectively, while plasticity of the RS material was slightly decreased. It was noticed that the grain size of both materials was at the same level of 2 μm, thus higher mechanical properties of RS material was ascribed to dispersion strengthening caused by the high amount of fine (below 50 nm in diameter) Mg17Al12phases evenly distributed in the material structure.
TEM Analyses of Microstructure Evolution in Ex-Service Single Crystal CMSX-4 Gas Turbine Blade
Authors: Dubiel Beata , Czyrska-Filemonowicz Aleksandra
Published: March 2012

TEM studies of the ex-service single crystal blade were performed to analyse the microstructural changes which control the degradation of the CMSX-4 superalloy during its exposure in a gas turbine. Microstructural analyses were focused mainly on evolution of the γ-γ’ morphology and examination of dislocation configurations in particular parts of the blade. Between the bottom and tip locations of the blade a pronounced differences in γ-γ’ morphology were observed. TEM analysis of the dislocation substructure showed that at the bottom of the blade the dislocation slip is mainly confined to the horizontal γ channels. Increasing of the temperature and decreasing of stress along the blade height resulted in the γ-γ’ rafting, formation of dislocation networks and intensification of the dislocation climb in vertical γ channels.
Structural Perfection of a Single Crystal Nickel-Based CMSX-4 Superalloy
Authors: Onyszko Arkadiusz , Bogdanowicz Włodzimierz , Sieniawski Jan
Published: March 2012

The aircraft engines turbine blades are manufactured from nickel-base superalloys and they are often in a single crystal form. This ensures the best high-temperature creep resistance as compared with blades of equiaxial grains microstructure and of columnar grains microstructure. Turbine blades were manufactured in an ALD Vacuum Technologies furnace. The study has examined structural perfection of single crystal blades obtained by Bridgeman method from CMSX-4 nickel superalloy at various withdrawal rates: 1, 2, 3, 4 and 5mm/min.
THEED Study of CrTe Thin Films Obtained by Pulsed Laser Deposition
Authors: Sagan Piotr , Kuzma Marian
Published: March 2012

Ferromagnetic semimetals are valuable materials for spintronic applications . Recently, several theoretical papers reported that a good candidate in this respect is zinc-blende (ZB) CrTe. We report the THEED measurements of thin CrTe layers obtained by pulsed laser deposition on (100) KCl substrate by YAG:Nd 3+ laser. Layers were grown from tablets of pressed powder Cr2Te3. Films have good mirror-like morphology. High resolution diffraction patterns show a number of sharp Debye rings. Careful analysis points on the complex composition of the layers consisting mainly with hexagonal and cubic CrTe. Hexagonal structure of CrTe shows an unexpected lattice constants a = 4.181Å, c = 7.324 Å), while in the literature (J. Dijkstra et al. J. Phys. Cond. Matter 1, 9141 (1989)) these constants are 3.997Å, c = 6.222 Å. Inclusions of Te as well as hexagonal Cr are not excluded. The phases of Cr2Te3 and Cr3Te4 are observed as well.
Characterization of Composite Based on Al–Cu–Co Alloy
Authors: Bogdanowicz Włodzimierz , Krawczyk Jacek , Albrecht Robert
Published: March 2012

Composite based on Al–Cu–Co alloy obtained by directional solidification, were characterized. The quasicrystalline decagonal D phase of Al64Cu20Co16 was the reinforcement and the singlecrystalline tetragonal T phase of Al72Cu27Co1 was the matrix of the composite. The phases were identified by powder X-ray diffraction (XRD). The composite was analysed by light optical microscope and electron microscopes. The SEM and TEM techniques were used. Additionally the Laue method was used. The results of the study showed that the reinforcement has a form of parallel fibres of 20-40 μm diameter. Quasicrystal structure of fibres contained the phason strain. The quasicrystalline phase in the form of decagonal columns was also present inside composite pores.
VM12 Steel for Advanced Power Generation Plants – Metrology of the Precipitates by Electron Microscopy
Authors: Zielińska-Lipiec Anna , Czyrska-Filemonowicz Aleksandra , Kozieł Tomasz
Published: March 2012

A new high chromium martensitic steel, VM12, was recently developed for advanced coal-fired ultra-supercritical steam power plants. A very important factor in maintaining high creep resistance during service exposure is its stable microstructure, in particular high dispersion particle strengthening, which slow down the recovery and softening processes of the matrix. Quantitative characterisation of the precipitates in the VM12 steel as received condition and after creep tests up to about 30000 h at 625 °C using TEM was carried out.
Transmission Electron Microscopy Studies of X210CrW12 and 100CR6 Thixo-Cast Steels
Authors: Rogal Lukasz , Dutkiewicz Jan
Published: March 2012

Two kinds of deformed carbon steel were used as a feedstock for thixoforming: X210CrW12 tool steel cold worked, of composition 2,1 %C, 10,5 %Cr, 0,7 %W, 0,4 %Si (all in weight %), and bearing steel 100Cr6: (0,9% C, 1,4% Cr, 0,4% Mn, 0,3% Si, 0,2% Cu). The microstructures of X210CrW12 steel after thixoforming process at temperature of 1230°C, performed at 30 % of liquid show presence of globular grains (average size from 30 µm 50 µm) surrounded by the eutectic mixture. Measured chemical composition of the austenite in globules was: 2,5% C, 0,4% Si, 0,7% Mn, 12% Cr, 1,3% W, 0,1%V, 87% Fe and that of the eutectic mixture: 5%C, 0,4% Si, 0,6%, Mn, 1,1%, W, 17,5% Cr, 75,4% Fe in thixocast of X210CrW12 steel. Measured carbon content is too high, most probably due to contamination effect. TEM studies of this steel after thixoforming shows that the eutectic mixture consists of ferrite α-Fe and Cr7C3 carbides. Thixoforming of 100Cr6 bearing steel was conducted at temperature of 1420°C at about 25 % of liquid fraction. Thixocast microstructure consists of globular grains consisting of martensite needles and residual austenite (20 μm to 40 μm in size and average composition 0,9%C, 1,4 %Cr, 0,5%Mn, 0,3%Si). The chemical composition of the eutectic is following: 2,4% C, 2,6% Cr, 0,2%Si, 0,6%Mn.
SEM and TEM Microstructure Characterization of a Commercial Purity Aluminum after Laser Treatment
Authors: Rozmus-Górnikowska Magdalena , Major Łukasz , Morgiel Jerzy
Published: March 2012

The effect of the Laser Shock Processing (LSP) on the microstructure of the surface layer of a commercially pure alluminum was studied. LSP process was performed with a high-power Q-switched Nd:YAG ReNOVALaser, operating in a pulse mode (18 ns), with a power density of 0,43 GW/cm2. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and a Scanning Transmision Electron Microscopy (STEM) have been used to study the microstructure of the surface layer of the investigated material after laser treatment. SEM investigation showed that after LSP process surface melting occurs but is restricted to a thin layer. However, both TEM and STEM images indicate that under the thin melting layer a high density of dislocations were visible. It has been found that the laser beam with employing parameters caused plastic deformation of the surface layer of the investigated aluminum.