bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Implementation of Compiler Subsystem for Object Oriented Publish/Subscribe Systems
Authors: Dong Biao
Published: November 2013

Existing methodologies based on the request/response model for system software design, rooted in principles of object-oriented design, lead to tightly-coupled interactions, and lack coordination capacities. The publish/subscribe (P/S) paradigm is particularly suitable for loosely-coupled communication environment. A design of event and subscription models under an object-oriented environment was motivated by the idea of using P/S paradigm for an object-oriented environment. A compiler subsystem for object-oriented P/S Systems was studied. In the subsystem, its form, working process, and typical algorithms were analyzed from the point of object-oriented and technology of P/S paradigm separately. Experiment was simulated in the following two aspects: users model and middle code generation, and shows that using the P/S service improves the usability of P/S systems.
Anomaly Detection Based on Chi-Square Statistic Technology in Computer Information System
Authors: Gu Ming
Published: November 2013

Algorithm and principle of anomaly detection technique based on a chi-square statistic was designed. In order to verify the effect of principle and algorithm, testing data of sample of Windows7 and Mac OS system was presented and compared. The results of this study show that chi-square technology achieves the 0% false alarm rate and the 100% detection rate for abnormal intrusion scenarios. All intrusion scenarios are detected at the first or second audit event.
Evaluation Fitness of Footwear Using Hybrid Simulation
Authors: Li Meng Jian , Geng Wei Dong
Published: November 2013

This research is trying to develop a process for identifying comfortable shoe last for human feet. A hybrid of geometric model and physics based model is proposed to simulate the procedure of fitting foot into footwear. The system implemented is able to construct all meaningful slicing planes used in footwear industry. And all kinds of dimensions are measured for fitness check, especially the most important three girth of human feet and shoe last, i.e., ball girth, waist girth, and instep girth. Quantified Fitness range, known as dimensional difference (DD), is updated according to positive and negative samples. Result shows that comparing with geometric based method, our method significantly improves the percentage of comfortable shoes among all shoes that are guided by former fitness evaluation method.
Optimisation to ANN Inputs in Automated Property Valuation Model with Encog 3 and winGamma
Authors: Vo Nguyen , Shi Hao , Szajman Jakub
Published: November 2013

An automated property model for prediction of the sales price of residential properties with optimized inputs was developed. Optimised inputs improve efficiency and speed of an Artificial Neural Network (ANN). Property appraisal ANNs have a great potential not only to save time and money but also help local government authorities to determine the tax revenue. While the criteria for the ANN’s number of hidden layer neurons are well known, there is no theory to support the optimisation to ANN inputs. The proposed optimisation to ANN inputs procedure aims to resolve some of the issues in using ANNs especially in the case of automated property valuation modelling (AVM). A brief review of ANNs and their applications is given, followed by the discussion of the ANN design methodology and optimisation. Details of ANN optimisation using Java based Encog 3 and winGamma are presented in this paper. It is shown that optimisation to ANN inputs can improve the accuracy in residential property evaluation using winGamma and Encog 3.
The Technology of Software Reliability Virtual Test Based on Software Conventional Failure Data
Authors: Ai Jun , Shang Jing Wei , Liu Yang
Published: November 2013

The technology of software reliability quantitative assessment (SRQA) is based on failure data collected in software reliability test or actual use. However, software reliability testing is a long test cycle and difficult to collect enough failure data, which limits SRQA in the actual project. A large number of software failure found from the software growth test cant be used because the process has nothing to do with the actual use or no record of failure time. In this paper, software reliability virtual testing technology based on software conventional failure data is presented. According to the internal data association between input space of software reliability test and failure data found in conventional software testing, a data matching algorithm is proposed to obtain possible failure time in software reliability testing by matching conventional failure data and the input space. Finally, the imitate engine control software is used as the experimental subject to verify the feasibility and effectiveness of the method.
Design and Implementation of a Cache System in Web Search Engines
Authors: Ma Hong Yuan
Published: November 2013

Web search engine caches the results which is frequently queried by users. It is an effective approach to improve the efficiency of Web search engines. In this paper, we give some valuable experience in our design and implementation of a Web search engine cache system. We present there design principles: logical layer processing, event-based communication architecture and avoiding frequent data copy. We also introduce the architecture presented in practice, including connection processor, application processor, query results caching processor, inverted list caching processor and list intersection caching processor. Experiments are conducted in our cache system using a real Web search engine query log.
Design and Realization of Music Player Based on Android System
Authors: Nie Ru , Huang Cheng Can
Published: November 2013

With today's society pace of life are becoming more and more quickly, with hardware mobile devices are becoming more and more advanced, people's requirements for mobile equipment are increasingly high, from the pursuit of technology to the pursuit of vision, therefore, people gradually improve the requirements for system. In this paper the music player design is based on the Android open source system technology, use of the Java language and the Eclipse programming tools. This music player can be achieved the music playback, pause, previous song, next song, music list, sound control in android platform-based design, performance is good, can operate independently in Android system.
The Application of Technology of Virtual Instruments in Testing System for Hydraulic
Authors: Li Ping Cai , Guan Hao
Published: November 2013

The Concept of a virtual instrument and the computer aided testing system for hydraulic based on technology of virtual instruments are represented in this paper. Virtual instrument technology is employed to construct the software and hardware framework. The modularized system gained features high flexibility and expandability.
Film Defects of Lithium Battery Recognition Based on Brightness and One-against-All Support Vector Machine
Authors: Chen Gong , Zhu Xi Fang , Xu Qing Quan , Xu An Cheng , Yang Hui
Published: November 2013

Lithium battery film on-line defect recognition system is realized based on industrial charge-coupled device (CCD) to improve quality. Otsu algorithm is adopted for threshold instead of traditional method. Area of defect is sorted to get the largest defect and geometry and projective is extracted from image. Film defects of lithium battery recognition is realized based on Brightness Judgment and One-against-all support vector machine (OAA-SVM). Experiment results show that these methods are effective and feasible, the accuracy can reach 90%.
Blind Recognition Algorithm of TT&C Signals of Satellite Based on Fast-ICA Algorithm
Authors: Wang Le , Zhang Jing Dan
Published: November 2013

A blind sub-carrier recognition algorithm of TT&C communication is proposed based on Negentropy-maximization in terms of recognition of TT&C signals for military TT&C communication information scout. First, the basic principle of the ICA is discussed in this paper. Using maximum Negentropy approximation of differential Negentropy, an objective function for ICA is introduced and a Fast-ICA algorithm based on maximum Negentropy is presented. Based on analyzing Fast-ICA algorithm deeply, this paper expounds a new method to adopt it in the recognition of TT&C signals of satellite. Simulation results in MATLAB show its better performance and efficiency in the mixed TT&C signals of satellite recognition, proving its good convergence and robust.
Overview of Micro-Force Sensing Methods
Authors: Ma Chao Zhe , Du Jin Song , Liu Yi Yang , Chu Yun Kai
Published: November 2013

At present, reliable micro-force sensing is one of the most important research for micromanipulation and micro-assembly. Six kinds of methods to detect micro-force are described in this paper. Analysis of the basic principle and detection accuracy of each sensing method, and applications in micro-assembly and micromanipulation are briefly introduced. The purpose of this paper is to be useful to provide some references for scholars engaging in the micro-force sensing, which in turn promotes automatic processing level of micro-assembly and micromanipulation to reliably manufacture micro devices of high quality.
A New SPIHT Image Coder Based on Fast Lifting Wavelet Transform
Authors: Song Wei , Fan Wen Bing
Published: November 2013

To improve PSNR and coding efficiency, the paper proposes a method by improving algorithm according to image compression technology to pledge the real time of the image transmission and gain the high compression ratio under the image quality. The improved SPIHT image coding algorithm based on fast lifting wavelet transform presents fast lifting wavelet transform to improve transform course, because of many consecutive zero appearing in SPIHT quantification coding, adopting the simultaneous encoding of entropy and SPIHT. Entropy coding adopts run-length-changeable coding. Proved by the experiment, the method could achieve expected purpose, can apply in the image data transmission and storage of remote image surveillance systems.
An Equipment Fault Sound Location System Design
Authors: Xie Dong , Wang Min , Zhu Jian Qu , Wang Feng
Published: November 2013

The location of the sound source is an important technique for equipment failures diagnostic application. This paper design a specific fault sound location system for capturing the specific sound source and determine its orientation. The two functions of sound recognition and location system are combined. The frequency domain characteristics based on similarity calculation method is used to identify the sound signal. The source localization algorithm based on the time delay estimation is used to calculate the time difference of arrival sound signal. By method of combining hardware circuit preprocessing and software design, the orientation of positioning of sound source is determined by the known sound pickup arrays spatial position. The sound location system uses two piece of MCU to achieve its function with simplification efficient algorithm and high accuracy.
Vibration Analysis of Different Micro-Beams with Laser Ablation
Authors: Xiong Liang Cai , Zhou Quan Sheng , Chen Peng
Published: November 2013

The dynamic response of different micro-beams after laser excitation experiments have been investigated in this paper. The impact force that induces the vibration of micro-beams is the interaction of focused pulse laser and tested beams. The impact response of micro-beams after being excited is measured by Laser Doppler Vibrometer. Different beams such as cantilever beam, L-shaped beam are employed in our experiments. Comparisons of the vibration velocity and its frequencies of different beams have also been performed. Experimental results show that the mechanical effects of laser shock do really exist and can be utilized.
Research and Development of CVIS Testing System at Road Intersection Based on ZigBee
Authors: Zhang Hao
Published: November 2013

The traditional traffic light control system which applies timer control cannot adjust the light time period effectively when the vehicle flow changes. Based on the Cooperative Vehicle Infrastructure System (CVIS), this paper puts forward a scheme that traffic light can be changed adaptively according to the vehicle flow. It realizes the interactive communication among moving vehicles, roadside equipments and control center. As a result, the traffic light time period is regulated by the real-time feedback data.
Analyzing of the Near-Field Shielding Effectiveness of the Cylindrical Cavity with Apertures
Authors: Fan Jie Qing , Hao Jian Hong , Song Zi Xian , Liu Xue Fen
Published: November 2013

The equivalent circuit model of shielding effectiveness of the cylindrical cavity with apertures against the near-field waves of electric dipole is established. The analytical formulas for approximately calculating the shielding effectiveness are given by the adjusted transmission line method. It is shown that the near-field shielding effectiveness of a cylindrical cavity with apertures is far inferior to that of far-field. The near-filed SE of the cylindrical cavity increases with the distance between the diploe and the apertured cavity, but when the distance is greater than a half wavelength of the electromagnetic disturbances, the SE tends to be saturated. In the cavity, the electric SE increased with the distance of observation points to the apertures. Results of the adjusted TLM are in good agreement with the CST simulation results.
Design and Thermal Analysis of SiGe HBT with Segmented Emitter Fingers and Non-Uniform Emitter Finger Spacing
Authors: Chen Liang , Hu Cheng Zhong , Jiang Chun Ling
Published: November 2013

A novel multi-finger power SiGe heterojunction bipolar transistor (HBT) with segmented emitter fingers and non-uniform emitter finger spacing was proposed to improve the thermal stability. Thermal simulation for a five-finger power SiGe HBT with novel structure was conducted with ANSYS software. Three-dimensional temperature distribution on emitter fingers was obtained. Compared with traditional emitter structure, the maximum junction temperature of novel structure reduce significantly from 429.025K to 414.252K, the thermal resistance reduce from 159K/W to 141K/W, temperature distribution were significantly improved. Thermal stability was effective enhanced.
The Design and Simulation of Cycled Amplifying Circuit
Authors: An Na , Gong Cheng Long , Su Weng Ming
Published: November 2013

There are many traditional methods to detect the weak signal(such as, locking -receive, synchronous cumulative and double channel de-noising) When the signal is very weak which easily submerged by the device noise,the error that measured by the above methods is too big. This paper mainly introduces the principle of a adaptive control faint signal cycle amplifier and through the method of error compensation to amplify signal cycled , which improve the signal-to-noise ratio and reduce the detection error. The structure of this system is simple and it cost low. besides,it convenient for use and debug. The circuit can also be applied to data acquisition and processing of weak signal and its significance is very widely .This paper designs a simulation circuit and analyzes sample-hold and analog switch.
Application of an Auto-Disturbance Rejection Controller in Planar Motor Speed Control System
Authors: Liu Xin Mei , Li Xiao Fei
Published: November 2013

In order to solve the problem of poor performance of the planar motor speed control system under PID control, the paper proposed an auto-disturbance rejection control scheme, on a sudden load or some disturbances, which solved the contradiction between "rapidity" and "overshoot" under PID control by using ADRC to estimation, compensation and control. This paper described in detail the composition of ADRC and the construction of planar motor speed controller. And on the sudden load and friction, the results of comparing the auto-disturbances rejection control and PID control show that the ADRC has better dynamic performances and robustness.
Path Planning for Nonholonomic Mobile Robot in Dynamic Environment
Authors: Kang Liang , Mao Lian Cheng
Published: November 2013

Based on introduction of the fluid diffusion energy, the model for path planning is presented. The adaptive mesh is used to solve the equation model for path planning. Based on the dynamic model and kinematic constraints of the nonholonomic mobile robot, a trajectory tracking controller is designed. Theory and calculation results prove that, as a new method for mobile robot path planning, the equation of the fluid diffusion energy for nonholonomic mobile robot path planning is feasible and effective.
A Design of Electric Control and PLC System for NC Milling Machine Based on SINUMERIK 802D Solution Line
Authors: Yang Ding , Liu Shuai
Published: November 2013

In this paper, an NC milling Machine transformation scheme based on SINUMERIK 802D sl system is introduced. This transformation aims to fulfill the needs of both production practice and NC teaching, the electrical system and PLC control system are particularly designed for this object. It is validated that the transformed NC milling machine has perfect functions and high reliability, providing useful reference for the transformation of this type of machine tools.
Automatic White Balance Based on Gray World Method and Retinex
Authors: Xu Li Li , Jia Bao Xian
Published: November 2013

In different illumination, the same scene has different images. These images have different color. While adjust the image color, white balance is a very critical step. In the color adjustment, effective and automatic white balance algorithm can realize the intelligent adjustment of image color and save time. There are two kinds balance methods are Gray world method and Retinex theory. Two methods are commonly used. These have different treatment goals and have different characteristics. And their applications are relate to image attribute. Therefore, the two methods are combined and improve the white balance effect. In this paper, image was processed with gray world method firstly. Using the color constancy of Retinex, we maintain the green channel. We use nonlinear methods to adjust the pixel intensity. Through different parameters, we change the R, G, B channel value and realize the non linear adjustment of image intensity. The experimental results show that the proposed automatic white balance method can effectively avoid image distortion and keep the white balance is better.
Study of CDR Real-Time Query Based on Big Data Technologies
Authors: Gao Zhi Heng , Chen Kang , Bi Ling Yan
Published: November 2013

This paper describes big data technology layers, analyses the CDR (Call Data Records) real-time query scenario of telecommunications and brings forward a fast indexing and query solution based on the open source Hadoop platform. A CDR real-time query system was built according to the solution. A performance test was conducted with the real dataset of a city with 3 million subscribers. Compared with the existing system, the big data solution can greatly improve data processing performance and support real-time query with lower hardware and software investment.
Fault Diagnosis of Induction Motors Based on RBF Neural Network
Authors: Ding Shuo , Chang Xiao Heng , Wu Qing Hui
Published: November 2013

In order to improve the diagnosis accuracy of stator short circuit faults of three-phase induction motors, in this paper, a method using three-layered RBF neural network is proposed to diagnose the short circuit faults on the basis of analysis of structure and algorithm of RBF neural network. Then the approach to establish RBF neural network and the influence of different expanding coefficients upon the diagnosis accuracy are illustrated. The simulation results show that RBF neural network can successfully diagnose and classify six typical short circuit faults of induction motors. This method has a faster speed, higher accuracy and it needs fewer samples. In conclusion, RBF neural network is practical, efficient and intelligent in fault diagnosis of induction motors.
Multiple-Input Single-Output Wireless Power Transmission System for Coal Mine Application
Authors: Zhao Duan , Ding En Jie , Xue Hui
Published: November 2013

The magnetic multiple input algorithms of Wireless Power Transmission (WPT) system as well as many multiple overlapping coils structures in the transmitter side are proposed for the coal mine Internet of the Things (IOT) nodes. Different phase shifts cases for the input signal are considered to study their effect on the efficiency. Simulation results showed that the axial component of magnetic induction resulted from the multiple overlapping coils structure has preferable homogeneous distribution over the traditional single input coil. The proposed system achieved an efficiency value of 60 % for a receiver placed 40 cm away from a 4 coils transmitter comparing to an efficiency value of 50% for the same distance using a single coil transmitter. Simulation results shows that the proposed model is well adapted for the movable charging mode for the IOT nodes in coal mine.
Mapping a Real-Time System Graphics Design Model to Windows CE
Authors: Liu Xiao Yan , Ma Qin Tao , Fu Xiao Dong
Published: November 2013

Presents mapping rules of a real-time system graphics design model to system calls and C++ application framework under Windows CE platform, based on research and analysis for an abstraction executive of real-time software and Windows CE, including the mapping rules of task, semaphore, interrupt and alarm object. The principles of communication between real-time objects and mapping methods are given.
The Research on the Adaptive Network English Learning of Guizhou University
Authors: Song Yan Li
Published: November 2013

It appears that the adaptive English material can enhance students English abilities. This paper model the adaptive network English education platform according to the actuality of Guizhou university students, this platform can afford the most appropriate English materials, it will have a great role in promoting the English education teaching reform and advancing the students level by reducing the differences.
A Non-Repudiation E-Mail Transmission Protocol and its Formal Analysis
Authors: Ren Ze Ming , Xu Ling Yun , Liu Qian , Fan An Dong
Published: November 2013

In order to reduce the amount of data exchange in E-mail transmission process, a non-repudiation E-mail transmission protocol was proposed based on the digital signature technology. By using the formal analysis based on the extended strand space method, strict authentication and analysis were conducted for the security of data transmission and the identity of both the transmitter and receiver. Furthermore, the safety and effectiveness of this protocol were verified.
Optimizing Mechanical Properties of a 0.3C-1.5Si-3.5MnQuenched and Partitioned Steel
Authors: Hajy Akbary Farideh , Santofimia Maria Jesus , Sietsma Jilt
Published: November 2013

The Quenching and Partitioning (Q&P) process is known as a promising method for producing steels with superior mechanical properties. Developing Q&P steels with optimized mechanical properties requires well understanding of the relation between their microstructural and mechanical properties. The microstructural evolution during different Q&P processes in a 0.3C-1.5Si-3.5Mn (wt.%) steel was analysed. Mechanical properties of the developed microstructures were measured by using microtensile test. The influence of volume fractions and carbon contents of the phases on the ductility and strength of the microstructures was investigated. Furthermore, the effect of the specimen size on the tensile properties was discussed and a correction procedure was applied to convert the measured microtensile properties to the standard ones. A comparison with the measured mechanical properties of other type of Advanced High Strength Steels (AHSS) shows the improved properties of the Q&P steels.
A Novel Severe Plastic Deformation Process for Shear Deformation and Grain Refinement of Bulk Materials
Authors: Montazeri-Pour Mehdi , Habibi-Parsa Mohammad
Published: November 2013

A novel experimental technique called "Multi-Axial Incremental Shearing" (MAIS) is proposed to impose plastic shear strain to the bulk metallic materials. The evolution of strain during MAIS processing of AA1100 alloy has been studied by employing 3D finite element modeling. The commercial code DEFORM was used to analyze the deformation and evolution of the working load with rams displacement as the material passes through the die. Simulation results showed that a large amount of accumulative strain can be applied to the sample without change of its dimensions. In order to verify the metal flow and microstructure characteristics, Sn-1wt.% Bi alloy specimens as the representative of the soft metals have been deformed by MAIS process.
Influence of Fuel and Condition in Combustion Synthesis on Properties of Copper (II) Oxide Nanoparticle
Authors: Sadabadi Hamed , Aftabtalab Adeleh , Zafarian Shirzad , Chakra Shilpa , Rao K. Venkateswara , Shaker Sarah
Published: November 2013

Copper oxide nanoparticles have been received attraction due to their unique properties and potential future applications. In present work nanostructure Copper (II) oxide (CuO) spherical nanoparticle synthesized by solution combustion method and the influence of different fuel and condition on the properties of CuO particle was investigated. Crystalline phase and size indicated by applying XRD and particle size distribution studied further using DLS. Scanning electron microscopy (SEM) was used for morphological study and EDAX analysis shows composition of CuO particles. Nanostructure of copper (II) oxide particle studied further by Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) applied for detail study on crystalline structure of particles.
Development of Nano-Structure Cu-Ti Alloys by Mechanical Alloying Process
Authors: Pourfereidouni Ahdie , Akbari Gholam Hossein
Published: November 2013

Cu-Ti system with a terminal solution in the Cu-rich portion of equilibrium Cu-Ti phase diagram with a decreasing trend with temperature shows a potential to develop age hardenable alloys with suitable strength and thermal and electrical conductivities. In the present study, the mechanical alloy process has been employed to increase solubility of Ti in Cu matrix to make age hardenable Cu alloys. Cu-Ti powder mixtures with different rations of 1 and 6 wt% of Ti were milled in planetary ball mill for different milling times of 4, 12, 48, 96 and 192 hours. The milled powder mixtures were investigated and characterised by X-ray diffraction (XRD) technique. The results show increasing in lattice parameter of Cu, which indicates that Ti atoms are dissolved in the Cu matrix. Cu crystal sizes showed decreasing trend which were more obvious in the mixture with higher Ti contents. The final crystal sizes were in the range of 17-23 nm after 192 hours of milling.
An Investigation on the Effect of the Catalyst on Physical Properties of Silicon Oxide Nanostructures Prepared by CVD Technique
Authors: Heidaryan Narges , Eshghi Hosein
Published: November 2013

Here, nano and microstructures of silicon oxide layers grown on p-Si (111) wafer have synthesized by evaporating SnCl2.2H2O powder in a mixture of Ar and O2 gas flow using chemical vapor deposition (CVD) technique. The growth temperature and the vacuum pressure were 950 °C and 10-3 torr, respectively. Through this study, samples have characterized by SEM, XRD, EDS and PL methods. The grown sample while has a combination of porous and layered morphology, it has a polycrystalline nature including a mixture of SiO2-x (002) and SnO2 phases. The EDS elemental analysis confirmed the presence of Si, O and Sn atoms in the composition, which is consistent with the XRD data. The PL spectrum show a strong peak in violet region (424 nm) attributed to the crystal defects at the SiO2-x and SnO2 interfaces.
Synthesis & Study of Nano Size Copper Oxide Particle via Chemical Method
Authors: Abdolhosseinzadeh Maryam , Khodamoradi Niloofar
Published: November 2013

Copper oxide nanoparticles have been synthesized using micro reactors made of bis (2-ethylhexyle) sulfosuccinate (AOT)/water/n-Hexane microemulsions. The controls of particles size was achieved by varying water to surfactant molar ratio (W0). At constant of surfactant concentration the increases in value of W0increased the population of micelles and resulted in lager particle size. Their sizes and appearance were characterized by TEM, SEM, Zetasizer, uv-visible methods. Scanning electron microscopy (SEM) showed the spherical morphology of as prepared CuO nanoparticles. The Transmission electron microscopy (TEM) showed 85 nm size of as prepared CuO particles.
Frequency Analysis of Nano Sandwich Structure with Nonlocal Effect
Authors: Rahmani Omid , Ghaffari Solmaz
Published: November 2013

This study deals with the frequency analysis of Nano-sandwich-structure with nonlocal effect. The model takes into account the flexibility of the sandwich core while the faces are treat as beams. The different stiffness of core will impart different vibration characteristic of the structure. To examine free vibrations of Nano-sandwich-structure, nonlocal elasticity theory has been applied. In this paper an investigation is carried out to understand the small-scale effects in the free vibration. The boundary conditions of simply-supported conditions are described here. Further the effects of scale coefficient and stiffness parameter are studied in this manuscript.
Investigating on the Reverse Transformation of Martensite to Austenite and Pseudoelastic Behavior in Ultrafine-Grained Fe-10Ni-7Mn (wt %) Steel Processed by Heavy Cold Rolling
Authors: Koohdar Hamidreza , Nili-Ahmadabadi Mahmoud , Habibi-Parsa Mohammad , Ghasemi-Nanesa Hadi
Published: November 2013

Fe-10Ni-7Mn (wt. %) steel is a member of ultrahigh strength steels which shows good ductility in the solution annealed condition and excellent age hardenability. In the current research, this alloy was subjected to heavy cold rolling in which the reverse transformation of martensitic to austenite was brought about. From the XRD, DSC and dilatometric analyses, it is resulted that after 60 % cold rolling the austenite phase may be formed by displacive mechanism. Stability of austenite at room temperature is referred to the ultrafine/nanograin size of austenite after deformation which prevents the austenite to martensite transformation. The presence of ultrafine/nanoaustenite formed by displacive mechanism leads to the observation of new mechanical properties during cyclic tensile test. This behavior is known as pseudoelastic phenomenon. In this behavior, during loading-unloading tensile cycle, the shape of the specimen return to its original configuration with a hysteresis loop in its path to the zero strain point.
Structural Changes in Poly(lactic acid)/Hydroxyapatite Nanocomposites by Gamma Irradiation
Authors: Dadbin Susan , Naimian Faranak , Hasanpoor Sorour
Published: November 2013

Poly (lactic acid)/hydroxyapatite (PLA/HAP) nanocomposites were made via solution casting method and subjected to gamma irradiation at doses of 30 and 50 kGy. FTIR spectra of the nanocomposites displayed structural changes in the crystalline phase of PLA upon irradiation. The PLA/HAP nanocomposites of 6 and 10 pph HAP irradiated at 30 kGy showed higher tensile strengths. This was attributed to radiation-induced crystallinity that verified by DSC crystallinity measurements. Using triallyl isocyanurate (TAIC) as a multifunctional monomer promoted radiation-induced crosslinking reactions in PLA that was manifested by improvements in the tensile strength of the nanocomposites. Optimum values for TAIC, irradiation dose and HAP content were found as 1 pph, 30 kGy and 10 pph respectively. Raising the irradiation dose from 30 to 50 kGy prompted chain scission reactions that had adverse effects on tensile properties.
Evaluation Nanostructure Properties of Bioactive Glass Scaffolds for Bone Tissue Engineering
Authors: Izadi Samaneh , Hesaraki Saeed , Hafezi-Ardakani Masoud
Published: November 2013

The use of biomaterials in bone tissue engineering newly has been developed. They are biocompatible material which are reabsorbed in body and replaced with newly formed tissue. Bioactive glass scaffolds will be appropriate candidates if pore morphology, size and structures are controlled. Scaffolds with nanostructure will provide these goals. In this research bioglass powder was synthesized with sol-gel method to achieve nanostructure powder. The glass powder was characterized with transmission electron microscope (TEM). Scaffolds were prepared with combination of bioglass powder and sugar as porogen followed by pressing at 80 MPa then sintering at 1050 oC. The morphology of sintered scaffolds was characterized with scanning electron microscope (SEM) and porosity was measured with density method. Mechanical properties were assessed with compressive strength. The TEM results show that synthesized powder has particle size about 25 nm. The SEM results show that nanopores and macropores are connectively distributed in whole part of scaffolds. The compressive strength of scaffolds was 0.8 MPa. Overall, the scaffold is suggested that is appropriate alternative for bone tissue engineering.
Enhanced Photoluminescence Effect of Poly(L-lactide) Biodegradable Polymer with Functionalized Carbon Nanotubes
Authors: Amirian Maryam , Nabipour Chakoli Ali , Zamani Zeinali Hossein , Afarideh Hossein
Published: November 2013

Functionalization of Multiwalled Carbon Nanotubes (MWCNTs) for biological applications was considered. For this purpose, the pristine MWCNTs (pMWCNTs) are covalently aminated using p-amino benzoic acid and phosphoric acid without shortening of pMWCNTs. The grafted amine groups on the sidewall of pMWCNTs are useful as initiator for grafting of polymer chains on the sidewall of aminated MWCNTs (MWCNT-NH2). The PLLA homopolymer chains grafted covalently from the sidewall of aminated MWCNTs successfully. The FT-IR spectra revealed that the amine groups and the PLLA chains grafted form the sidewall of pMWCNTs strongly. The fluoroscopy test results shows that the pMWCNTs and aminated MWCNTs have not any significant photoluminescence (PL) effect at 350 nm excitation. The MWCNT-g-PLLAs exhibit an extremely strong visible emission at 404 nm and 429 nm. These results may be ascribed to the contribution of oxygen vacancies and defects at the end chain of grafted PLLA chains on the sidewall of MWCNTs that created by Sn atoms of initiator during polymerization on the sidewall of MWCNTs. The oxygen vacancies usually act as radiative centers in the PL process. In addition, The MWCNT-g-PLLAs enhance the PL of neat PLLA. The PL of composites slightly diminishes with blue shift during in-vitro degradation. As mentioned above, the MWCNT-g-PLLAs are the functionalized MWCNTs that applicable in the field of medicine. Due to biocompatible and biodegradable molecular groups on the sidewall of MWCNTs, it is predictable that the MWCNT-g-PLLAs will pass all exams for its application in medicine.
Characterization of CIGS Thin Films Fabricated from Nanoparticles under Selenization Process
Authors: Zarei Hadi , Malekfar Rasoul
Published: November 2013

In the present report, the synthesis process of CuInxGa1-xSe2 nanoparticles as an absorption layer in tetraethylene glycol using metallic chloride and Se powder for the purpose of solar cell application. Whole processes were performed under glovebox condition. Nanoparticles sizes were achieved via manipulation of reaction temperature and various precursor concentrations. CuInxGa1-xSe2 or CIGS nanoparticles with diameters in the range of about 20-50 nm were prepared via polyol route and purified through centrifugation and precipitation processes. Then nanoparticles were dispersed to obtain stable inks that could be directly used for thin-film deposition via spin coating.
Then, CIGS nanoparticles were coated on soda lime glass for fabrication of inorganic thin film solar cell via spin coating as a film. In those devices, the prepared films yielded relatively dense CuInGaSe2 films with some void spaces. For elimination of the void spaces, the nanocrystals were exposed to selenium vapor atmosphere. Filling the voids with selenium can lead to the fabrication of CIGS absorptive layers having good dense structures and high efficiency. CIGS thin films were characterized by various analytical tools, such as XRD, UV-Visible spectroscopy and SEM imaging.
Nano Hydroxyapatite as a Corrosion Resistant Coating of AZ31 Magnesium Alloys
Authors: Saremi Mohsen , Mohajernia Shiva , Hejazi Sina
Published: November 2013

nanohydroxyapatite (n-HAP) was coated on to AZ31 magnesium alloy in order to reduce the surface corrosion rate and enhance the bio-compatibility. N-HAP was successfully coated by pulse electrodeposition technique. Morphology and composition of the coatings were investigated by scanning electron microscopy and X-ray diffraction methods, respectively. The corrosion behaviors of the coatings were studied by tafel polarization and impedance spectroscopy tests. Results demonstrated that the porosity of the nanostructure coating decrease in comparison with micro structure coating and therefore, corrosion resistance of AZ31 was improved significantly. Also, the adhesion of nanostructure coating was increased and thus it can be introduced as a suitable coating for body implants.
Magnetic Nanoparticles Supported Binuclear Manganese(II) Complex via Covalent Interaction: A Highly Efficient and Reusable Catalyst for the Epoxidation of Cyclohexene
Authors: Ghorbanloo Massomeh , Tarasi Roghayeh
Published: November 2013

In the present work, the highly efficient epoxidation of cyclohexene catalyzed by Fe3O4@SiO2/([Mn2L(HL)(H2O)4], is reported. First, the Fe3O4@SiO2 nanoparticles were modified with (3-chloropropyl)-trimethoxysilane (CPTMS) group and then [Mn2(HL)2(H2O)4] was attached to the support via covalent linkages. The prepared catalyst was characterized by spectroscopic studies and chemical analyses. This catalytic system serves as catalyst for the oxidation of cyclohexene to cyclohexene epoxide and 2-cyclohexene-1-ol using H2O2 as an oxidant. Thus, this catalytic system shows high activity and selectivity toward cyclohexene epoxide. Also activity of the immobilized catalyst remains nearly unchanged after five cycles, that it is truly heterogeneous.
Effects of Anodic Oxidation in Ethylene Glycol Based Electrolyte on the Corrosion Resistance and Biocompatibility of NiTi Shape Memory Alloy
Authors: Pourmahdavi Maryam , Parvin Nader
Published: November 2013

Nickel titanium (NiTi) is the most attractive shape memory alloy in industrial and in medical application but suffer from corrosion attack by body fluids. Nowadays, Electrochemical anodization has become a popular surface modification method for biomaterials. In this study we prepared TiO2 coating with nanoporous surface morphology on NiTi shape memory alloy by using electrochemical anodization in ethylene glycol based electrolyte followed by annealing in 600 °C and explored its appropriateness for biomedical applications. Morphology and crystal structure of the film was characterized by Field emission scanning electron microscopiy (FE-SEM) and X-ray diffraction (XRD) tests. The corrosion resistance of the treated NiTi alloy was investigated by potentiodynamic polarization test and The findings showed that the anodization in ethylene glycol solution extremely increased the corrosion resistance and hence biocompatibility.
Polyamide Decorated Graphene Sheet as a Potential Antimicrobial Agent: Synthesis, Characterization
Authors: Fathali Elahe , Rahimnejad Sara , Yousefi Mohammad
Published: November 2013

We propose an innovative approach to impart graphene properties to the surface of thin-film composites polyamide. Specifically, biocidal properties were obtained by covalently binding graphene to the polyamide surface. Grafting of polymer onto graphene generate nanocomposites, which heighten anti-bacterial property by changing on morphology and graphene structure. Purpose of this survey is studying the degradation of bacteria wall by grafted graphene to polyamide. In this study, the graphene should be functionalized in order to boost the side activities, antitoxin property and dispersion in solution. Then, the covalent bonds are established between graphene and polyamide by a linkage function such as ethylendiamine. The result of grafting polymer has been characterized by TGA, SEM and XRD and evaluated for the anti-bacterial property of grafted polymer by analysis on E.Coil bacteria cells. The test of bacteria in present of grafted polyamide lead to destruction of 62% of bacteria in 1 hr.
Effect of Powder Particle Size and Substrate Hardening on the Formation of Nanostructured TiC Coating on AISI-D2 Steel by Mechanical Milling
Authors: Saba Farhad , Raygan Shahram , Abdizadeh Hossein
Published: November 2013

In this study TiC coating was formed on AISI-D2 steel by mechanical milling. In this regard, steel sample, balls and the powder were placed within a milling vial. Ball milling were carried out with annealed and quench-tempered samples using TiC powder having particle sizes of 44 and 200 μm for 5, 10, 15, 20, 50 and 100 h. During milling treatment, sample surface was exposed to high energy collisions and powder particles trapped between balls and sample adhered to the surface through cold welding. It was shown that the thickness and the structure of the coating depended on powder particle size; hardness and milling time. The thickness of the coating increased at first and decreased thereafter with milling time. The results showed that the substrate hardening decreased the thickness of the coating. Scanning Electron Microscopy (SEM) was employed to investigate the structural characteristics of the coatings. X-ray Diffraction (XRD) analysis was also conducted to determine the kind of phases in the coating. SEM investigations showed that the greatest thickness of the coating was reached after 20 h of milling. Furthermore, no new phases were detected in the XRD results after 100 h. It was shown that the thickness and hardness of coatings with coarse particle size were lower than that of the other. It was revealed that lattice parameter of TiC coating increased with milling time.
Mechanical Behavior and Properties of TiN/TiC Coating Using PACVD
Authors: Azadi Mahboobeh , Rouhaghdam Alireza Sabour , Ahangarani Shahrokh , Mofidi Haman Hedaiat , Valiei Maryam
Published: November 2013

A comparison of the mechanical behavior of double-layer (TiN/TiC) coatings with a single-layer (TiN andTiC) coatings has been done in this paper. All coatings with the thickness of 2-3 μm were deposited onto H13 hot work tool steel, by the technique of the plasma assisted chemical vapor deposition (PACVD). Compositional and structural properties were investigated by the glancing-angle X-ray diffraction (GIXRD) and the field emission scanning electron microscopy (FESEM). Coating mechanical characterizations were also investigated by the knoop hardness indentation; the pin on disc wear test and the atomic force microscopy (AFM) for assessing the hardness, the wear resistance, the surface topology and roughness variations. Mechanical properties such as the hardness, the wear resistance and the surface roughness were changed when the materail type of layers in coatings was variable. The TiN/TiC coatings showed the maximum microhardness (>27 GPa) and had a better wear resistance than the single-layer coatings. Lower surface roughness was also related to the TiC coating.
Electrochemical Behavior of S-Doped Nanostructured TiO2 Layer Synthesized with PEO Process for Photocatalytic Applications
Authors: Ahmadzadeh Mohammad , Ghorbani Mohammad
Published: November 2013

Sulfur doped and pure micro-nanoporous TiO2 film were synthesized with PEO method to produce a film with a high surface area for photocatalysis applications. The effect of applied voltage and electrolyte concentration on the microstructure and photocatalytic properties of the prepared layer were investigated via SEM, XRD, EIS and DRS studies. Electrochemical Impedance Spectroscopy (EIS) was carried out in order to determine the corrosion and electrochemical properties of the produced layer. It was found that although the barrier layer resistance decreases with the voltage, the layers porosity and consequently the surface area increases. Finally the XRD and DRS spectrums were correlated with corrosion and photocatalytic properties in order to find out the optimum parameters of the PEO process to synthesize a layer with desired Properties.
Influence of Nitrogen Gas Flow on Mechanical and Tribological Properties of Sputtered Chromium Nitride Thin Films
Authors: Jafarzadeh Morteza , Khojier Kaykhosrow , Savaloni Hadi
Published: November 2013

Nitride based hard coatings are widely used for mechanical applications. Among these coatings, chromium nitrides are especially interesting because of its good mechanical and tribological properties. In this work we have studied the influence of nitrogen gas flow on mechanical and tribological properties of chromium nitride thin films. The chromium nitride thin films were deposited on Al 5083 by DC magnetron sputtering technique at different nitrogen gas flows in the range of 5-20 sccm. Surface morphology and chemical composition of the films were studied using field emission scanning electron microscope (FESEM). The thickness of the films was determined by quartz crystal monitor and checked with FESEM cross-section images. The mechanical and tribological properties of the samples were investigated by means of nanoindentation and scratch tests. The results showed that films hardness increased with nitrogen gas flow, while coefficient of friction and scratch volume decreased. The structural investigations showed that these behaviors were due to the decrease of dislocation density and improvement of crystal quality.
Liquid Phase Surface Treatment of Ti-6Al-4V Titanium Alloy Pre-Sprayed with TiC/Ni Using Pulsed Nd-YAG Laser
Authors: Ghorbani Hassan , Sohi M. Heydarzadeh , Torkamany Mohammad Javad
Published: November 2013

In the present work Ti-6Al-4V titanium wrought alloy was initially sprayed with TiC-15 wt% Ni powder, before being liquid phase surface treated by pulse Nd-YAG laser. Microstructure, chemical composition and phase analysis and hardness of the treated layers were studied by using field emission scanning electron microscope (FE-SEM), energy dispersive spectrometer (EDS), X-ray diffraction analysis (XRD) and micro-hardness test respectively. The result showed that the treated layers had ultrafined dendritic structure containing nanosize TiC particles and their hardness were as high as 982 HV0.03respect to 350 HV0.03for the base material.
Combustion Synthesis and Sintering of TiB2-Al2O3 Composites; Investigating the Effects of Different Al-Content as a Precursor
Authors: Montakhab Elham , Hadian Ali Mohammad
Published: November 2013

Titanium diboride (TiB2) ceramics have unique physical and chemical properties such as excellent electrical conductivity, high melting point and good corrosion resistance. But due to its relatively low sinterability, the use of this material is currently limited. The addition of Al2O3 to TiB2 can improve its fracture toughness, flexural strength, sinterability, and impact resistance. In this paper, TiB2-Al2O3 composite powders were produced by self-propagating high-temperature synthesis (SHS) method with reductive process from H3BO3-TiO2-Al system. Aluminum and magnesium were used as reductive elements to provide sufficient heat as primary driving force to obtain TiB2-Al2O3 composite. Due to the lower energy release in using aluminum as the initiator of the SHS process, finer microstructure can be achieved. Different stoichiometric amounts of aluminum as precursor were added to the mixture to examine its effect on the reaction progress. To evaluate the complete chemical conversion of the reactants, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analyses were carried out. The highest conversion ratio was obtained from the sample containing 1.2 stoichiometric amount of aluminum.