bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on MFBP Algorithm of Nerve Net Self-Adapting Controller
Authors: Fu Xiao Juan , Wu Hong Kun
Published: November 2013

The nerve net self-adapting controller aiming at some AC servo system is designed on the basis of Mathematical Modeling. The controller includes two forward nerve nets with three layers. One is designed to identify the nerve net system named NNI and the other is to control the nerve net system named NNC.NNC use special learning algorithm to control system and at the same time improve its constringency pace through introducing new MFBP algorithm. The MFBP algorithm is programmed using MATLAB. The system’s Steady state error is no more than 0.2mil under the step response,speed response and accelerated response.According to the results of the simulation and experiments, the nerve net self-adapting controller has a high quality of static、dynamic performance and restrain the infection to system performance under hard circumstances like large inertia,variety load and huge change of torsion.
Research of a LED Intelligent Light System for Plant
Authors: Liu Gang , Tian Li Guo , Li Meng , Guan Bei Bei , Wu Hai , Chen Gao Li , Cheng Xiao Liang
Published: November 2013

Light environment is one of indispensable environmental factors for plant growth, and it is regulatory role for the development of plant growth morphogenesis and photosynthesis, etc. For the plants sodium uses too much power and cost issues, according to the demand characteristics of plant growth, proposed and designed a parameter adjustable LED intelligent light system. The core of system is ARM processor, using time control and PWM, etc. To achieve the modulation for quality of light, light intensity, photoperiod, and ways of working ( slider control to simulate the rising sun). The experiment proved that this system can provide the light needed for plants and reduce plant growth cycle. After the practical application, the system works well.
Research and Application of Optical Fiber Sensing Technology on High Voltage Transmission Line Monitoring
Authors: Yang Hong Lei , Liang Shi Bin , Miao Xue Peng , Cao Min , Chang Ming
Published: November 2013

On-line monitoring of high voltage transmission lines can prevent or reduce the accidents of transmission reduced by icing,wave,breeze vibrations of electric wires and the dropping of electrical insulators.An on-line monitoring system of high voltage transmission lines based on optical fiber sensing technology is setted in this paper.Fiber optic signal demodulation instrument in the transformer substation receives the signal sent by the optical fiber Bragg grating sensors fitted on transmission lines and electric power towers,and then the signal was sent to the transmission line monitoring center by the power system network.Field hang net experiments shows that the system can monitor the high voltage transmission lines accurately for a long time.
A High-Accuracy and Robust Low Drop-Out Regulator for Outdoor Decorative Lighting LED Driver
Authors: Pan Lu Wei , Zhou Li , Sun Tao , Wei Ying , Gao Yuan Yuan , Chen Peng
Published: November 2013

A high-accuracy and robust LDO was designed based on CSMC 0.5um 40V BCD process, it was integrated in an outdoor decorative lighting LED Control and Driver SOC. The input of SOC was a 12V~40V power which was used by LED lamp. The LDO converted the input power of SOC to a 5V power for the Digital Control and Signal Transmission circuits inside the SOC. Due to the application requirements of SOC, the robustness of LDO in-55°C~150°C temperature and 12V~40V power voltage conditions must be guaranteed. The process variations and application conditions would affect the output voltage of LDO, 3 bits digital trim signal Trim [3: and a trim circuit were utilized to improve the accuracy of LDOs output voltage. Simulation result shows that the LDO works robustly and the output voltage accuracy can be improved to ±0.5% max in all conditions after being trimmed.
A Realization Method for Multi-Carrier MPPSK Modulations
Authors: Zhang Peng , Wu Le Nan
Published: November 2013

In order to realize multi-carrier transmission of MPPSK modulation, a method was proposed after analyzing the cause of the internal channel interference (ICI) among multi MPPSK signals. The ICI was eliminated by reducing the modulation order of each MPPSK signal to a certain level and modulating MPPSK signals to different parts of a same symbol cycle. The information rates of single carrier modulation and multi-carrier modulation were compared to illustrate the role of order reduction. The BER performances of single carrier modulation and multi-carrier modulation were also carried out by simulations. Results show that: the proposed method can achieve MPPSK multi-carrier transmission, with higher information rate than that with single carrier modulation and no BER performance loss, which is expected to be an available scheme for improving spectrum efficiency.
Design and Implementation of Long Distance Visible Light Communication System Based on Embedded ARM Platform
Authors: Zhou Meng Mi , Zhang Ming Lun , Zhang Yan Gan
Published: November 2013

In this paper, a long-distance optical communication system based on Embedded ARM platform is presented and demonstrated. The system is composed of two parts: LED/PD application terminal and its drive circuit. Terminal has a 4-inch touch screen with interactive interface based on Android system. The performance of data transfer in our prototype shows up to 50 m range at the transmission rate of 50kbps. This system is supposed to reach the distance of 2km or higher in the coming months.
Evolution of Fault Self-Repairing Circuit with High Reliability
Authors: Lou Jian An , Li Yang , Yu Jian Hua
Published: November 2013

With the continuous improvement of the complexity of the microelectronic system, its reliability risk is becoming more and more obvious. In order to improve the reliability of electronic systems in complex electromagnetic environment, this paper proposes a new fault self-repairing method; the idea is to realize controllable silicon evolution on the FPGA. A MicroBlaze CPU and VRC array are designed, and the CPU runs the evolutionary algorithm to configure the VRC array, dynamically changing the structure and function of the circuit, so as to obtain high reliability of the digital fault self-repairing circuit. Evolving fault self-repairing technology provides a new way for the high reliability of the digital system design.
Development of a Soft Starter with Current-Limiting, Reactive Power Compensation and Harmonic Filtering
Authors: Wang Yi Fei , Yuan You Xin
Published: November 2013

Aimed at the high starting current, low power factor and low running efficiency, a novel soft starter with current-limiting, reactive power compensation and harmonic filtering is developed in this paper. The following works have been done in the study: the research of topological structure, the design of hardware and software of the control system, the validation of experimental result. It has been successfully applied to the fans load of 10kV, 19000kW, and got better effects, and satisfies the characteristics of the current-limiting and reactive compensation during this motor starting. It can also realize the power harmonic filtering after the motor soft starting, improve the whole starting performance, save energy and keep the grid voltage stable, with easy engineering implementation and high cost performance.
Intelligent and Compositive Protector for Motor Based on AVR Single-Chip Microcomputer
Authors: Wang Zheng Hao , Yang Zhong Li , Yu Zhi Liang , Zheng Xue Fan
Published: November 2013

A kind of intelligent and compositive motor protector designed by ATMEGA16 single-chip microcomputer was introduced. The product, which has a set of high precision, high sensitivity and reliability, has many functions, such as overload or lightload protection, phase loss, overvoltage or lightvoltage, short circuit, locked rotor, leakage and phase imbalance protection. This product is a perfect substitute to the traditional motor protection devices, which has a good cost performance and broad market prospects.
Design of WLAN Anti-Interference λ / 4 - Absorber's Parameters in 4G Era
Authors: Zhao Hui Chao , Hao Wan Jun , Yi Ying Ying , Dong Yi Feng , Wu Fan , Wang Ming Ming , Chen Dong Wei
Published: November 2013

The problem of WLAN anti -interference has become an important issue that affects the application. This paper explores the electromagnetic parameters' optimization of λ/ 4 type dielectric absorber in 2.4GHz and 3.6GHz .Studies show that: through the early design of the material's parameters, such as complex permittivity and thickness, the obtained ideal electromagnetic parameters' area can achieve a predetermined reflectivity at the desired frequency , then choose material to get high absorbing preparation , which can provide design basis for the preparation of different frequency band and high performance electromagnetic wave absorber.
Video-Conferencing-Device to Engineering
Authors: Šedivý Josef , Drtina René , Rabe Vlasta
Published: November 2013

Video conferencing is gradually becoming one of the possible uses of ICTs. The question is, what do you mean by videoconference imagine - it could be a combination of two videophones with stakeholders, one-way transmission from the conference room to a public or private network and bi-directional connection of several subjects. The main objective of the conference participants to create space for the latest knowledge and skills confronting the international arena.
1×4 Power Splitter Based on Cascaded Multimode Interference Photonic Crystal Waveguide
Authors: Shen Xiao Xia , Ren Ya Zhou , Dong Guo Yan
Published: November 2013

Using of cascaded multimode interference waveguides in 2D photonic crystal power splitter are investigated by modeling and computation. Results show that with a five line defect waveguides and one pair of three line defect waveguides integrated, the total normalized transmission can be high as 94.9% with 30nm broad spectrum calculated and simulated by finite-difference time-domain method.
Interworking of LTE with CDMA EVDO
Authors: Xiao Zhe Yun
Published: November 2013

This paper introduces how the interworking happens between LTE with CDMA EVDO. It shows different kinds of behaviors during handoff between LTE and CDMA EVDO.
Application of Computer Vision Technology in Agricultural Field
Authors: Zhang Fang , Fu Li Si
Published: November 2013

Computer vision technology has been widely applied to various fields of agricultural development, and with the rapid development of computer technology, graphics and image processing technology, enormous progress has been achieved on its applications in agriculture. This paper has reviewed and summarized the development of computer vision technology mainly in detection and grading of the quality of agricultural products, crop monitoring, automation of agricultural production, crop disease identification and other aspects and has discussed the prospect for future development.
LDPC Codes with the Layered LLR-BP Algorithm for 3GPP
Authors: Li Miao Miao , Li Jian Ping , Cai Chao Shi
Published: November 2013

We propose a layered log-likelihood-ratio-based belief propagation(LLR-BP)algorithm for Low Density Parity Check (LDPC)codes. In the conventional decoding algorithm, the process of decoding would be terminated when it reaches the maximum iterative number or the near-convergence is achieved. The proposed algorithm is based on the variable node information quantification and stop updating criterion thought. By dividing the absolute value of the variable node to different layers, a part of the check nodes stop the iteration before reaching the maximum iterative number to save iterative time. From the simulation results, we know that the improved decoding algorithm successively achieves lower computation complexity than the conventional one .And the layered LLR-BP algorithm is a better scheme for LDPC codes.
Design of Dynamic Vision System for Modular Reconfigurable Robots
Authors: Tang Jian Bing , Chen Bin , Zha Ya Bing
Published: November 2013

Modular reconfigurable robots (MRRS) is an approach to building robot for various complex tasks with the promise of great versatility, robustness and low cost. It can be used extensively to meet the demands of different tasks or different working environments by changing its shapes, such as from snake first to loop and next to quadruped, and so on. Therefore they can travel over or through obstacles, and go though small pipe. Even they can walk somewhat like a person on crutches. The quantity of the motion pattern will decide the adjustable ability of MRRS. So, dynamic vision system is very important for MRRS, which can improve its moving ability and intelligent degree. With the help of the dynamic vision system, the robot can accomplish different tasks in different working environments by itself, such as deciding routes and avoiding obstacles. In this paper, the dynamic vision system for MRRS will be analyzed and researched roundly, and three control approaches, such as open loop tracking, close loop servo and active vision system, are put forward.
Research on Fuzzy Evaluation Method of Reliability Analysis about Robot for Work of Drainpipe Deposit Cleaning
Authors: Xu Feng Ping , Zhao Zhi Cong , Zhou Yan
Published: November 2013

Based on the theory of fuzzy mathematics and system reliability, one kind of methods of fuzzy evaluation of reliability analysis about robot for work of drainpipe deposit cleaning was presented in this paper. The method is to divide the robot into several subsystems, the influence factor of every subsystems reliability are the same, but each of subsystem weight subset and single factor evaluating matrix are different from each other, therefore the method considers not only different function of influence factor in evaluation model, but also different function of influence factor to different subsystems, so the method has comprehensive characteristics even more. Finally the reliability numerical analysis of the robot was given.
Intelligent Driver for Magneto-Rheological Damper Based on Digital Signal Controller
Authors: Huang Shan Yun , Chen Zhao Bo , Tu Feng Chen
Published: November 2013

A novel intelligent driver based on digital signal controller (DSC) has been put forward for magneto-rheological (MR) damper. The working principles of MR damper were described, as well as the hardware circuit scheme of signal condition and MR damper driver etc. on account of TMS320F28335 DSC. A hierarchical control algorithm was designed and the studies for the performance of the driver were conducted. The results suggest that the driver could provide accurate drive current for MR damper, and meanwhile the respond time is less than 2ms, which can meet the drive requirements of MR damper.
Vehicle Power Grid Voltage's Influence on Anti-Disturbance Ability of Maglev Train
Authors: Huang Jin Hui , Hao A Ming , Li Xiao Long , She Long Hua
Published: November 2013

Maglev train operation process can be affected by a variety of disturbance force. The system stiffness should be improved in order to strengthen the train's anti-disturbance ability. The electromagnet input voltage will saturate when the system is disturbed by a large force. Since the electromagnet input voltage can only change in the range of the vehicle power grid voltage, the system performance is unable to be further improved by increasing the proportional feedback coefficient. Therefore an appropriate vehicle power grid voltage should be selected in consideration of the disturbance force the train may meet. In this paper, the mathematical model of magnetic suspension system was established according to the dynamics and electromagnetism theory. Then the working principle of the digital chopper and the linear generator was analyzed. Finally the relationship between the vehicle power grid voltage and the system anti-disturbance ability was explored. Gap changes of systems with different vehicle power grid voltage are compared in consideration of several common disturbing forces. The simulation results show that the higher the power grid voltage is, the stronger the system resistance ability to impact interference is. The existed 440 V vehicle power grid voltage can guarantee the stability of maglev train under 20 kN impact interference. But under more than 20 kN impact, train may crash the track. By selecting 500 V power grid voltage, the trains' gap change will be less than 5 mm, under 20 kN impact interference.The gap overshoot volume is reduced by 35.2% compared with that with 440 V power grid voltage.
Attitude Controller Design of Multiple Independently Targeted Reentry Vehicle Based on Internal Model Control
Authors: Zhao Fei , Li Fan , Zhao Jian Hui
Published: November 2013

A Multiple Independently Targeted Reentry Vehicle (MIRV) is a ballistic missile payload containing several warheads each capable of hitting one of a group of targets. In the process of missile flight control, the release of warheads brings about coupling to the missile attitude control system which will lower the flight stability. In order to solve this problem, a missile attitude controller, which combined the α-order integral inverse system with internal model principle, was presented. Firstly, determine the Post Boost Vehicle (PBV) attitude dynamics model. Then, combine the linearization of attitude dynamics equation with feed-forward decoupling method to implement the attitude decoupling. Finally, a two-degree of freedom (TOF) multivariable internal model controller was set up to optimize the control system performance. Simulation results show that the coupling of attitude control system has been eliminated. Compared with the original system, the internal model controller provides the control system better input-tracking performance, robust stability and interference suppression capacity.
Research on Backlash Nonlinearity in Servo Precision Drive System
Authors: Zhou Wei , Zhao Ling , Li Xiao Lun , Lin Li Hong
Published: November 2013

Servo Precision Drive system is mainly composed of servo motor, mechanical transmission parts and control parts. Because of mutual coupling between various parts, particularly transmission system in mechanical coupling vibration in non-smooth transition, it will be of great harm to safe operation of the system. This paper is mainly from the perspective of backlash nonlinear characteristic and with simulation tool of Matlab/Simulink to analyze the influence of backlash on the precision of servo system, do hope the work above will have certain reference significance to actual engineering application.
Research on Relationship between Information Disclosure and Cost of Equity Capital for Small and Medium-Sized Enterprises
Authors: Zhang Yan Yu
Published: November 2013

Relationship between information disclosure and the cost of equity capital for small and medium-sized enterprises was studied by calculating the cost of equity capital using the residual income model. A multiple regression model was built considering economic condition in China. It was found that earnings information may help the small and medium-sized enterprise to reduce the cost of equity capital. One important motivation was that significant positive correlation was seen between financial leverage and the small and medium-sized enterprises cost of equity capital. Besides, negative correlation was seen between enterprise scale and the small and medium-sized enterprises cost of equity capital.
Research of Data Sparsity Based on Collaborative Filtering Algorithm
Authors: Liu Li Min , Zhang Peng Xiang , Lin Le , Xu Zhi Wei
Published: November 2013

During the traditional collaborative filtering recommendation algorithm be impacted by itself data sparseness problem. It can not provide accurate recommendation result. In this paper, Using traditional collaborative filtering algorithm and the concept of similar level, take advantage of the idea of data populating to solve sparsity problem, then using the Weighted Slope One algorithm to recommend calculating. Experimental results show that the improved algorithm solved the problem of the recommendation results of low accuracy because of the sparse scoring matrix, and it improved the algorithm recommended results to a certain extent.
Research for Cold-Start Problem in Network-Based Recommendation Algorithm
Authors: Liu Li Min , Zhang Chen Yang , Ma Zhi Qiang , Xiao Yu Hong
Published: November 2013

Network-based recommendation algorithm presents a good recommended result in many aspects. The algorithm is also facing the problem of cold-start. This paper proposes a solution for cold-start problem which makes use of an algorithm based on items similarity to calculate the similarity between the new item and other items in the system, and then link the new item to the user-item matrix. Finally the new items can be recommended to users by the network-based recommendation algorithm what the traditional network-based recommendation algorithm can't do. Therefore, the problem is solved on certain degree.
The Development of Student Information Management System Based on ASP.NET Workflow Technology
Authors: Wan Rong Ze , Xin Huang
Published: November 2013

With the rapid development of Internet, today's society has entered the Internet era, computer network provides a powerful driving force for social and economic development. Improve the students' management level by means of network technology, has a far-reaching significance to the construction of first-class college. This paper focuses on the management system of student information development of college analysis the current situation of college student management work and the construction goal in the future, the student information management system development significance is discussed. Based on the analysis of the technical characteristics of C/S model and B/S model, and according to the characteristics of Guangxi Agricultural-vocational Technique College learn internet system, the software architecture using B/S model the whole system; to improve the treatment efficiency of development scheme by using stored procedures and triggers; on ASP.NET technology and workflow technology are studied; and discusses how to use ADO.NET to access the database using ASP.NET technology to realize the method. This paper adopts XML technology to realize data exchange, the formation of a standard data exchange platform, make the system more open and extensible.
A Grating Generator for 3D Scanner Using CPLD
Authors: He Xing Zheng , Ma Jing Lan , Wang Wei
Published: November 2013

In the three-dimensional scanners (3D scanners), the grating generator is a key hardware. The commercial video projector is always used to act as the electronic grating generator normally. But there are some defects existed. Such as, the size is too large to setup in the case, it is not easy to be controlled by a single chip microcomputer, etc. To solve these problems, in this paper, a new type of grating generator was designed. A complex programmable logic device (CPLD) chip is used to control a liquid crystal on silicon (LCOS) video chip directly, and it works well.
Application and Research of Embedded Web Server on S3C4510B
Authors: Hu Kan , Lei Yuan Lin
Published: November 2013

With the rapid development of computer technology, embedded system is more and more widely used. The embedded hardware system was designed by taking Samsung ARM7TDMI CPU as the core. And a small uClinux system was embedded into this hardware system. Various kinds of applications in uClinux system can be developed. This thesis introduced one of those applications, which is embedded web server and its protocol-HTTP. In this thesis, the embedded system based on ARM had been developed. Our embedded system has the characters of low cost and high efficiency. It is at large applicated on business forwardly.
The Loan Pricing Study of Supply Chain Finance Based on Cloud Muster Warehouse (CMW)
Authors: Pan Yong Ming , Tong Yun Li , Mi Guan Xu
Published: November 2013

The CMW loan-pricing model is established by RAROC (risk adjusted return on capital) with consideration of performance measurement and risk management. The model was presumed interest income as all revenue and credit risk of economic capital the only risk. Model parameters were calculated with large amounts of processed data by cloud computing and internet of things. By donging this, financial institutions determined loan interest rates provided to SMEs (small and medium enterprises) in financing mode of CMW.
IoT Information Evolution in Perspective of Objective Knowledge Evolution Theory
Authors: Hu Liang , Ma Chen Xin , Song Guo Hang , Wu Fang Ming
Published: November 2013

According to general characters and proposing processes of the internet of things (IoT), this paper redefines Karl Poppers three worlds under the view of the IoT. Whats more, under this view it proposes a new information evolutionary model and imitates part of knowledge evolution process by using the testing environment hadoop cloud disposal platform. Analogy the knowledge evolutionary algorithm for the evolution of objective knowledge that exists in the IoT world, objective knowledge of the theory of evolution in the internet of things environment has some applicability. By using data processing and algorithm simulation, we could get closer to the objective truth to adapt to a higher degree of knowledge. This is the knowledge for smart home knowledge base provides a certain basis on a certain reference value. According the new window in looking into the IoTs information, it can provide new ideas in processing information.
Analysis Software Application Status of Enterprise Human Resource Management
Authors: Wang Cheng Che
Published: November 2013

The paper analyzes and evaluates the current domestic enterprise softwareapplication, first use the questionnaire investigation, mainly concentrated in the high-tech enterprises, the medium and small enterprises of high percentage. Researchmainly aimed at the software brand, satisfaction, function, price, purchase demand andimportance, after sale service and other aspects of the investigation. After screening screening to obtain effective questionnaires, and use descriptive analysis method toresearch the results of statistical analysis. The results showed: the enterprises shouldpay attention to the price of brand in the software selection, also need to compare products and after sale service function of comprehensive factors such as.
Based on the Experimental Platform of Litchi Picking Vision Calibration
Authors: Zhang Jiang Zhou , Zhang Jian Feng , Deng Ji Zhong
Published: November 2013

This paper constructs the picking mechanical hand binocular vision hardware system. Using an internal and external parameters calibration method of separation. In the calibration process, with calibration planar pattern translatory manner, appropriate for extracting feature points in the calibration template, through experiment and calculation to obtain the accurate parameters of camera model; external parameters calibration is a reasonable selection of reference coordinate system, through experimental analysis to obtain the two cameras outside parameter model.
Phosphorus Distribution in Electrodeposited Ni-P-Diamond Composites Influencing Structure and Mechanical Properties
Authors: Sadeghi Amir , Dietrich Dagmar , Mehner Thomas , Scharf Ingolf , Nickel Daniela , Lampke Thomas
Published: November 2013

The properties of Ni-P composite coatings are related to the microstructure evolution by co-deposition of phosphorus, particle incorporation and subsequent annealing. This study focuses primarily on the effect of phosphorus content in the electrolyte on the incorporation of sub-micron diamond particles in order to understand the complex influence of Ni/Ni3P crystallization and particle embedment on Martens hardness.
Transient Liquid Phase Bonding of Alumina to Alumina via Bismuth Oxide Interlayer
Authors: Dehkordi Omid Bahman , Hadian Ali Mohamad
Published: November 2013

Bismuth oxide, due to its low melting point was selected as filler for joining alumina to alumina using Transient Liquid Phase (TLP) method. For this purpose a thin layer of bismuth oxide was placed as an interlayer between the ceramic bodies. To study the effect of time and temperature on the mechanical properties of the joined samples, the joining tests were carried out in 900, 1000 and 1100°C for various times. The mechanical properties of the joined samples were measured using shear testing method. To investigate the microstructure of the joining area, the cross section ofthe joints were studied using scanning electron microscope (SEM) and X-ray diffraction method. The results showed that longer joining times results in higher mechanical properties of the joints. The highest joint strength of about 80 MPa was obtained for the sample joined in 900°C for 10hour.
Effect of Heat Treatment on the Phase Transformation from SnS to Pure SnS2
Authors: Orimi Rahim Lotfi , Mirdeylami Seyed Javad
Published: November 2013

SnS2nanoparticles were prepared by heat treatment of SnS nanoparticles at 300 °C under N2atmosphere for 1hour. SnS nanoparticles have been synthesized by chemical precipitation method. As synthesized SnS nanoparticles, for determining the optimal temperature, were heated at various temperatures; 100, 150, 200, 250 and 300 °C N2atmosphere for 1hour. The products are characterized by X-ray diffraction (XRD) , ultraviolet visible (UV-vis) absorbance spectra and photoluminescence (PL). XRD and optical absorption studies show an increase in particle size with increasing heat treatment temperature from 100 to 200 °C . However, a large decrease in the nanoparticle size along with transforming from SnS to SnS2 is observed at 300 °C.In addition, the optical properties of al samples , including both UV-vis absorption and emission spectra showed a blue shift as the particles size decreased.
Low Temperature Synthesis of a Stable Compound of Magnesium Aluminum Titanate Using Microwave Heating
Authors: Sedaghat Ali , Ebadzadeh Tooraj , Sobhani Manoochehr
Published: November 2013

The major problem associated with application of aluminum titanate is decomposition to Al2O3 and TiO2 oxides during heat treatment (in the range of 900-1280 °C ). In the present study, a stable compound of magnesium aluminum titanate ceramics (Mg0.6Al0.8Ti1.6O5) has been successfully synthesized with a straightforward non hydrolytic sol-gel process using inorganic metal compound. The raw materials were MgCl2.2H2O, AlCl3, TiCl4, and citric acid that were dissolved in ethanol. Prepared gel was dried at 120 °C and calcined at various temperatures using microwave heating. The results of X-ray Diffraction (XRD) and Simultaneous Thermal Analysis (STA) demonstrate that the direct crystallization of mono-phase magnesium aluminum titanate from fluffy precursor at a temperature below aluminum titanate decomposition temperature range is feasible. The formation of crystalline Mg0.6Al0.8Ti1.6O5 phase starts at about 400 °C. Also, Field Emission Scanning Electron Microscopy (FESEM) study and BrunauerEmmettTeller (BET) analysis represent the nanometric size of the mesoporous particles. The average particle size and specific surface area of powders were lower than 20 nm and more than 98 m2g-1, respectively, at low temperatures.
Processing of Al/SiC/TiB2 Hybrid Nanostructured Composites by Underwater Shock Wave Consolidation
Authors: Eskandari Hossein
Published: November 2013

Aluminum matrix hybrid nanostructured composites containing 30vol.%TiB2/SiC particles were manufactured by underwater shock consolidation method. Underwater shock consolidation is a one-stage densification process, which involves a very rapid and intense deposition of shock energy on powder particle surfaces. The interfacial microstructure and characterizations of this composite was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the interface is clean and no reaction zone generated along the interface between SiC/TiB2particles and Al matrix. Transmission electron microscopy reveals the development of nanostructures in the Al matrix after shock wave consolidation. Density, hardness and bending strength of the composites compacts were measured. The hybrid composite samples showed better improvement in the bending strength regard to Al-30 vol. %TiB2and also Al-30 vol.%SiC composites.
The Effect of Solvent on Drying Shrinkage of Novolac Xerogels
Authors: Naseri Iman , Kazemi Ali , Bahramian Ahmad Reza , Kashani Mehdi Razzaghi
Published: November 2013

Three sets of novolac xerogel prepared with various solvents and the effect of solvent on drying shrinkage investigated. The results show that the polarity of solvent has profound effect on microstructure of gel. As the polarity of solvent increases, the ultimate particle size and pore size decrease and consequently, the higher capillary pressure exerts on gel and hence, more shrinkage observed.
Nanocrystallization and Mechanical Properties of Rapidly Solidified Amorphous Al86Ni6Y6Ce2 (at.%) Alloy
Authors: Salehi Maryam , Shabestari S.G. , Boutorabi S.M.A.
Published: November 2013

Primary crystallization of amorphous Al86Ni6Y6Ce2(at.%) alloy was investigated through differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and X-ray diffraction. Moreover, nanoindentation analysis was performed to relate the hardness to the structure of the alloy. The kinetic parameters of the first crystallization process were determined by Kissinger method. The average amount of Avrami exponent (n=1.7±0.21) was concluded the primary crystallization occurred through three dimensional diffusion-controlled growth with decreasing rate. The α-Al nanoparticles 58 nm in size homogeneously embedded in the glassy matrix were formed during primary crystallization. Significant changes in the hardness occurred due to the change of the crystalline structures. The hardness of 7.30±0.58 GPa was obtained by annealing at 618 K with a microstructure of Al nanoparticles and Al3Ni intermetallic compound in an amorphous matrix.
Finite Element Simulation of a Novel Nano 3D Semiconductor Detector Fabricated by Anodizing the Aluminium
Authors: Esfandi Fatemeh , Saramad Shahyar , Jalilvand Mohammad Amin
Published: November 2013

The unique geometry of micro 3D semiconductor detectors, presents several advantages over conventional planar silicon detectors. But, manufacturing these kind of detectors requires high technology. The novel idea to achieve a high performance and low cost semiconductor detector is using the nanopattern of anodized aluminium as a mask to create nano3D detectors. The simulation results show that this novel nano3D radiation hard semiconductor detector with collection time less than 10 ps and full depletion voltage less than one volt can become increasingly important for possible future upgrades of 3D detectors of the Large Hadron Collider (LHC) at CERN and also medical imaging applications.
Macro-to-Nano Scale Modeling the Effect of Surface Energies on Surface Melting Phenomena in Metallic NanoTubes/Wires
Authors: Jahangir Vafa , Yaghmaee Maziyar S. , Riahifar Reza
Published: November 2013

Among nonomaterial with different geometric shapes, nanotubes and nanowires received special attentions with increasing applications in electronic industry and nanorobotic due to their unique properties. Therefore, in order to study the fundamental properties of nanotubes/wires, in this paper we will focus on modeling the melting of different crystal surface of metallic materials. Although there are different models in literature based on change of cohesion energy or coordination number at nanoscale, here we present a generalized thermodynamics model which considers layer by layer melting of nanotubes/wires. This model considered the surface energy of solid-gas, liquid-gas and solid-liquid along with the effect of fcc, bcc and hcp crystallography of different metals and their different surface crystal plane orientations. During the analytical simulation of surface melting, different run have been performed for variable size of tubes/wires in order to involve the size effect at nanoscale. Calculation results of model will be presented for some metallic systems such as: Ni, Pb, Fe and Zn. Results of our calculations show good agreement with experimental results and other theoretical predictions in literatures. Our model provides a powerful tool to analysis melting phenomena of metallic nanotubes/wires at different crystal structures and surface plane orientations for various sizes at nanoscale.
The Synthesis of Methylene Blue Photosensitiser Conjugated with Gold Nanoparticles
Authors: Kariminezhad Hasan , Khayat Omrani Sona , Habibzadeh Setareh , Agheb Maria
Published: November 2013

Nowadays, nanocarriers possess growing interest for medical usage such as photodynamic therapy. Conjunction of these nanoparticles with photosensitising drugs leads to more cellular uptake, higher photocytotoxicty, higher biocompatibility and more selectivity. Previous papers conclude that the 50 nm size nanoparticles give the highest cellular uptake for the purpose of photodynamic therapy. In this paper the gold nanoparticles were synthesized based on TurkevichFrens method. Moreover, methylene blue as a relevant photosensitiser was conjugated to achieved AuNPs. The spectrometric results of UV-visible and Fourier Transform Infrared spectroscopy (FTIR) as well as Atomic Force Microscopy (AFM) emphasis on the presence of MB sensitizers connected to resulting 50 nm gold nanoparticles.
Mechanical Properties Improvement of Porous Titanium-Bioglass Nanocomposites by Mechanical Alloying
Authors: Riahi Saeed , Rajabi Mohammad , Rabiee Sayed Mahmood
Published: November 2013

In this study, porous titanium-10 wt.% bioglass nanocomposites were fabricated by the combination of mechanical alloying and a space holder sintering process. The mixed powders were mechanically alloyed for 15 h. The blended Ti-Bioglass was mixed with 30 wt.% carbamide as a space holder. The mixtures were uniaxially pressed and finally, the green compacts sintered at 1150°C for 5 hours. The porous structures are characterized by X-ray diffraction method (XRD) and scanning electron microscopy (SEM). The mechanical properties were examined using micro hardness and compression tests. The investigation revealed that after 15 h of milling, the Bioglass dissolved in Ti lattice. Also, results show that nanostructured Ti-10 wt.% Bioglass with 31.5 nm crystallite size possess greater hardness compared to respective microcrystalline titanium and desirable compressive strength for using in biomedical application.
Numerical Modeling of Functionally Graded Coatings
Authors: Heidari Maryam , Kashtalyan Maria
Published: November 2013

Coatings play an important role in a variety of engineering applications protecting metallic or ceramic substrates against oxidation, heat penetration, wear and corrosion. One of the contributing factors to structural or functional failure of coatings is a mismatch of material properties between the coating and substrate at the coating/substrate interface. The concept of Functionally Graded Material (FGM) is actively explored in coating design for the purpose of eliminating this mismatch and improving coating performance and integrity. This paper presents analysis of the mechanical behavior of functionally graded coatings using commercial finite elements software ABAQUS in which user implemented graded finite elements have been employed. The model is used to carry out a comparative study of three-dimensional stress and displacement fields in the coated plates with homogeneous and functionally graded coatings.
On the Dependence of Mechanical and Tribological Properties of Sputtered Chromium Nitride Thin Films on Deposition Power
Authors: Goudarzi Saeideh , Khojier Kaykhosrow , Savaloni Hadi , Zalnezhad Erfan
Published: November 2013

In the past decade, Al 5083 has attracted considerable attention due to its promising potential applications in military vehicles. This paper reports the improvement of mechanical and tribological properties of Al 5083 coated with chromium nitride. Chromium nitride thin films were deposited by DC magnetron sputtering technique on Al 5083 substrate at different deposition powers (150 to 300 W in steps of 50 W). A FESEM was used for surface morphology and chemical composition studies. The thickness of the films was determined by quartz crystal monitor and checked with FESEM cross-section images. Films thickness was 2±0.01 μm for all samples. The mechanical and tribological properties were investigated by nanoindentation and scratch tests, respectively. The results showed that grains size decreases with the deposition power, while the samples produced at higher powers had a denser structure. The results also showed that by increasing the deposition power film hardness increased and the friction coefficient and scratch volume decreased.
Characterization of Nano-Structured Tin Oxide Film Prepared by Anodic Oxidation Process
Authors: Mortazavi S. Mohammad Reza , Rashchi Fereshteh , Nekouei Rasoul Khayyam
Published: November 2013

In this study, synthesis of tin oxide by anodic oxidation of tin foils at room temperature in oxalic acid has been investigated. The prepared structure was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). FESEM results showed that the anodization process leads to formation of nanoporous, cuboid and granular structures. EDS analysis in all tested samples showed the constituents of tin and oxygen.
Effect of Rapid Thermal Annealing on the Structural and Magnetic Properties of Nanostructured FePt Thin Films
Authors: Jalalizadeh Younes , Ghasemi Ali , Gordani Gholam Reza
Published: November 2013

The main goal of this study is to investigate the structural and magnetic properties of FePt thin film with respect to the annealing tempreture. The FePt thin films were deposited by RF magnetron sputtering on Corning glass substrates at a room temperature. The films were then post-annealed at the Range of 575-675°C for 20 s by rapid thermal annealing (RTA) at a high heating ramp rate of 100 °Cs. Phase identification of thin films was performed using X-ray diffraction (XRD). With employing SEM, the size and uniformity of grains were studied. Moreover magnetic properties of annealed thin films were evaluated using a vibrating sample magnetometer (VSM). XRD results showed that the ordered FePt structure is formed at 625°C. According to the hysteresis loops, maximum out-of-plane and in-plane coercivity reached 7kOe. this value was achieve at 675°C .These results reveal its significant potential as magnetic recording media for high-density recording.
Possibility of Growing Alloy Thin Film by Using Prepared Alloyed Powder in Electron Gun Deposition Technique
Authors: Raanaei Hossein , Abbasi Sadeq
Published: November 2013

In this article, we studied feasibility of growing Fe-Ni alloy thin films on both Si and glass substrates by using electron-gun deposition technique. Fe and Ni powders were mechanically alloyed with different percentages by ball mill technique. The final milled powder was used as a source material for depositing process. Powder materials were characterized structurally by using x-ray diffraction whereas grown thin films were analyzed by using x-ray reflectivity. The x-ray diffraction data of milled powder revealed a peak shift compared to the unmilled Ni and Fe peaks resulted in obtaining alloyed material. The distinct Kiessig fringes in the relative length scale are evidence of good layer quality in alloy thin films. The film grown on Si substrate exhibited more extended Kiessig fringes in reflectivity scans and the broadening of diffuse part in rocking curves scan became narrower as compared to the glass substrate; this indicated less interface roughness of the alloyed layer grown on silicon substrate. The chemical composition of the grown material was established through optical emission spectrometry. The results were much close to the percentage of prepared alloyed powder material.
Effect of Catalyst Type on Structural, Morphological, and Optical Properties of SiO2 Thin Film Applied by Sol-Gel Method
Authors: Lari Najme , Ahangarani Shahrokh , Shanaghi Ali
Published: November 2013

The application of antireflective coatings to the glass covers of solar thermal collectors, allows increasing the efficiency of the whole system. Among the methods for applying nanostructure coatings, sol-gel method was selected in this study. Via this method, an antireflective silica coating deposited on glass and the solar transmittance was investigated. The precursor solutions were made by mixing tetraethylorthosilicate (TEOS), ethanol, water and alkali (NH3) or acid (HNO3) catalyst in the molar ratio of 1:3.5:0.35:0.005. In addition, the role of two types of catalysts was examined. UV-visible spectroscopy, Fourier-transformed infrared spectrophotometer, Scanning electron and Optical microscopy were used for the characterization of silica thin films. Results showed that nanoporous silica layers cause to considerable reduction of these light reflections compared with uncoated glasses. It was found that the amount of reduction as well as the adhesive properties is depending on the type of catalyst. Results revealed that not only solar transmittance of acidic-catalyzed coatings is higher than of alkali-catalyzed coatings, but also acidic-catalyzed coatings possess adhesive-resistance higher than alkali-catalyzed coatings. However, at high pH condition, the condensation rate is very fast, and the growth tends to form spherically expanding clusters cause to increasing porosity. The dense and strong binding acidic-catalyzed films have a good antireflective property; because of that, the nanoporousity appears on the surface.
Effect of Current Density on Microstructure of Mn-Cu Thin Films via Electroplating Coating Technique
Authors: Haeri far Maryam , Zandrahimi Morteza
Published: November 2013

In the present study 304 stainless steel (SS) was electrochemical plated with nanocrystallineMn-Cu alloy coatings from a bath containing ammonium sulfate.The electrochemical investigation of Mn-Cu electrodeposited films was managed by potentiodynamic scans and galvanostatic experiments. The effect of current density on the microstructure, crystallographic structure, and chemical composition of the deposits were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive x-ray spectrometry (EDS), respectively.The results showed that Mn-Cu coatings obtained at low current density contain a large amount of Cu and heterogeneous microstructure, while at high current density uniform, compact, and amorphous coatings with a small amount of Cu was obtained. The results indicated that Cu co-deposition delayed the phase transformation of as-deposited ductile γ-Mn to the brittle and hard α-Mn. However, the results did not show any specific changes in grain size of the coatings with variation of current densities.
Fracture Toughness of TiN Coating as a Function of Interlayer Thickness
Authors: Mofidi Haman Hedaiat , Rouhaghdam Alireza Sabour , Ahangarani Shahrokh , Bozorg Mansoor , Azadi Mahboobeh
Published: November 2013

Single layer TiN and Ti/TiN bilayers were deposited on H-13 steel by plasma enhanced chemical vapor deposition technique. TiN thickness was kept constant at 2 μm and Ti thickness values ranged between 100 nm to 1 μm. Fracture toughness and residual stress of TiN coatings was measured as functions of thickness of titanium interlayer. Vickers indentation tests, X-ray diffraction, optical microscopy and field emission scanning electron microscopy were used to characterize the coatings. Results showed fracture toughness of the coating increases severely by increasing interlayer thickness. Additionally, internal stress which causes debonding and breaking of the entire coating, reduces about 70% by increasing interlayer thickness up to 600 nm. Moreover, there is maximum value for interlayer thickness in order to optimize fracture toughness of the coating.