bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Different Types of Pore-Forming Agent on the Macro Pore Size of Ceramic
Authors: Nasir Nurulfazielah , Jumaidin Ridhwan , Selamat Mohd Zulkefli , Salleh Suhaila , Lau Kok Tee
Published: May 2015

The aim of this study is to determine the effect of different types of pore-forming agent and sintering temperature on the pore size of ceramics. The porous ceramic material was developed by mixing of alumina, zeolite and calcium oxide (CaO) as the main materials and ethylene glycol as the binder. Meanwhile, two types of pore-forming agent were used, i.e., yeast and a mixture of aluminium powder and expandable polymeric spheres (EPS). The content of pore-forming agent was at 10 wt% of the mixture and the samples were shaped by using plaster of paris mould. After being dried, the samples were sintered at temperature range of 1000 up to 1500 °C for two hours. Microstructural analysis and pores size measurement were performed to determine the effect of pore-forming agent and sintering temperature on the ceramic. The result showed that yeast yielded larger pore sizes in the porous ceramic upon being sintered at 1400 °C for two hours, which were up to 402 μm. Therefore, yeast has the potential to be utilized as pore-forming agent in development of filter and wall insulation material.
Facile Surface Modification of Graphene Nanoplatelets (GNPs) Using Covalent ATPS-Dehydration (GNPs-ATPS) and Non-Covalent Polyetherimide Adsorption (GNPs-PEI) Method
Authors: Abd Razak Jeeferie , Ahmad Sahrim Haji , Ratnam Chantara Thevy , Yaakub Juliana , Azam Mohd Asyadi , Zainal Abidin Muhammad Zaimi , Abd Manaf Mohd Edeerozey , Mohamad Noraiham
Published: May 2015

Graphene nanoplatelets (GNPs), a newly discovered nanomaterial, promise a great potential in many technological applications. However, the direct usage of GNPs was limited due to several surface property factors that require innovative modifications and treatments. In this study, the GNPs surface treatment is carried out by using a covalent and non-covalent approach. The success of the treatment was determined and evaluated through the Raman and FTIR spectroscopy analysis, FESEM, TEM and XRD morphological observation. A strong vibration of Raman peak at 2081.11 cm-1 represent a possible covalent bonding of C=C due to the ATPS-silane treatment, while the characteristic peak at 1013.82 cm-1 indicates the aromatic ring nature of polyimide that non-covalently associated with C-H and C-C, as well as C-O-C linkage from the polyether. From the IR spectroscopy, the covalent treatment on GNPs was occurred through the dehydration mechanism while hydrogen bonding in the multiple structures of –OH that associated to the carboxylic acids was obviously involved for non-covalent treatment of GNPs. TEM observation of GNPs-PEI (polyetherimide) revealed a unique phenomenon of a polymeric adsorption as represented by a nanosize gray dot morphology in between of the GNPs platelets. In overall, the facile procedure of the surface treatment that was applied in this study is reliable to yield a different type of GNPs characteristic of covalent and non-covalent surface active, which may open up broad possibilities for various cutting edges applications.
Electrochemical Impedance Behavior of Various Composition Quaternary Ni Alloy in 3.5 Wt% NaCl
Authors: Zaimi Muhammad , Azam Mohd Asyadi , Sofian Azizul Helmi , Noda Kazuhiko
Published: May 2015

Zinc and copper addition into electroless Ni-P alloy matrix produces quaternary Ni alloy that exhibits lower corrosion resistance behavior compared to Ni-P and Ni-Cu-P alloy in 3.5 wt% NaCl solution. The corrosion behavior of the alloy is previously studied using the anodic polarization curve measurement. The results show that the corrosion potential of different alloy composition is almost similar to each other for electroless Ni-Zn-Cu-P alloy. However, the surface resistance of the alloy needs to be confirmed by using electrochemical impedance spectroscopy. The alloy was first deposited on an iron substrate using electroless Ni alloy deposition method approximately similar thickness at different plating bath pH of 8.50 and 9.50. The Ni alloy coated substrate was used as working electrode immersed into a solution of 3.5 wt% NaCl. The electrochemical cell consists of Pt and Ag/AgCl/KCl (saturated) as counter and reference electrode respectively. Electrochemical impedance measurement was done at open circuit potential. The measurement started from 100 kHz to 10 mHz with 10 mV of sinusoidal perturbation applied to the cell. Other types of alloy including Ni-P, Ni-Cu-P and Ni-Zn-P, were compared with Ni-Zn-Cu-P alloy. From the results, the Ni-Zn-Cu-P exhibits the lowest corrosion behavior compared to other Ni alloy due to low charge transfer resistance (Rct) observed small inductive loop at low frequency region of the Nyquist plot. Furthermore, the Nyquist plot for Ni-Zn-Cu-P for pH 8.50 and 9.50 showed comparable result; hence, the effect of pH has less effect on corrosion resistance of the electroless Ni-Zn-Cu-P alloy.
The Translucency of Yttria-Stabilized Zirconia in Dental Crowns: A Review
Authors: Chin Chuin Hao , Muchtar Andanastuti , Razali Masfueh , Azhari C.H.
Published: May 2015

Ceramics are increasingly popular in dental restoration after metal restoration has been found to be less esthetic. One such example is yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP). However, one of the challenges of this application is its insufficient translucency to ensure high esthetic restoration. This study reviews the effect of sintering parameters, primary particle size, microstructure homogeneity, and thickness of zirconia on its translucency. Several studies remarked that the thickness of the framework had the greatest effect on zirconia translucency. Thus, a rigorous thickness control is necessary. The consideration for optimal sintering parameters (sintering temperature and holding time) and the use of smaller particle sizes help in the densification and elimination of porosity in zirconia, which, consequently, improve its translucency. Finally, a homogeneous microstructure can reduce the light scattering effect in zirconia and increase its translucency. Identifying the factors that influence zirconia translucency can contribute to future research in improving the esthetic dental restoration.
Characterizations of NiAl-Al2O3 Produced Using Gel Combustion Synthesis Method
Authors: Afandi N.F. , Manap Abreeza , Misran Halina , Othman S.Z. , Pauzi N.I.M.
Published: May 2015

NiAl is widely used for elevated temperature application because it gives better properties, especially in the gas turbine application. This study was done in order to investigate the effects of calcination temperature on NiAl and α-Al2O3 formation using gel combustion synthesis method. This method used fatty alcohol and fatty acid ester for producing NiAl powders. X-Ray diffraction patterns of calcined samples exhibited NiAl and α-Al2O3 at temperature 1050°C. Therefore, nanostructured NiAl-α- Al2O3 can be successfully produced with the gel combustion method using less expensive and more environmental friendly fatty alcohol and fatty acid ester as fuels.
Fracture Toughness of AZ61 Magnesium Alloy with Various Thickness
Authors: Mohd Daud Mohd Ahadlin , Zaiedah Nasir Nurulhilmi , Selamat Mohd Zulkefli , Dhar Malingam Sivakumar
Published: May 2015

The critical fracture toughness parameter KΙC of AZ61 magnesium alloy was determined on the three point bent specimens with notch designed according to ASTM E399 standard. Five specimens having different thickness, i.e., 2, 4, 6, 8 and 10 mm were considered in order to evaluate the effect on fracture toughness. The stress intensity factor range ΔK was constant ~1x 10-8 for every specimen until the critical crack length reached half of the width of the specimens. The fracture test was done with the speed rate 0.12-0.15 MPa√m/sec until the specimens broke. The experimental results showed that the critical plain strain fracture toughness KΙC is 12.6 MPa√m and the highest plain stress fracture toughness KC is 16.5 MPa√m.
Wear Behaviour of Cryogenic Treated Recycled Carbon Fibers Filled Epoxy Composite
Authors: Law Mei Lin , Ahsan Qumrul , Ab Maulod Hairul Effendy , Mohamad Noraiham , Sivaraos Sivaraos
Published: May 2015

Mechanically ground recycled carbon fibers (rCFs) reinforced polymer composites were investigated in this paper. The rCFs were collected from the woven prepreg waste. The as-received (rCFs-AR) and cyclic cryogenic treated (rCFs-T) carbon fibers were incorporated separately in the epoxy matrix composite. The objective of this study is to study the wear behaviour of the epoxy composites with respect to the as-received and treated rCFs. Prior to the composite fabrication, the surface morphologies of rCFs-AR and rCFs-T were examined with the scanning electron microscope (SEM). It is found that the cryogenic treatment is effective in removing the epoxy resin from the carbon fiber due to the mismatches in the thermal expansion at the interface of rCFs and epoxy. The rCFs-AR and rCFs-T were homogeneously distributed in epoxy resin through ultrasonication. The void-free samples were then fabricated using vacuum casting technique. Micro Pin-on-disc Tribotester (CM-9109) was used to test the tribological behaviour of the polymer composites. The coefficient of friction (CoF) and wear rate of epoxy composites revealed that the reinforcement effect of rCFs-T is better than that of the rCFs-AR as the incorporation of rCFs-T decreases the CoF and improves the wear resistance of epoxy composites in comparison with rCFs-AR. The tribological results clearly showed that the rCFs was a valuable product worth to be reused as reinforcement in the new composite, as the incorporation of treated rCFs was effective in improving the tribological properties of the epoxy composites.
HRTEM Analysis of Magnetron Sputtered Ni4Al Thin Films
Authors: Anand T. Joseph Sahaya , Azam Mohd Asyadi , Sivaraos Sivaraos , Buang Zolkepli , Rajan Rajes K.M. , Hazliza Nurul , Zaidan Mohd , Chua Kok Yau
Published: May 2015

The nanostructural characteristics of direct-current magnetron sputter-deposited Ni4Al alloy films were studied during in situ isothermal annealing in a transmission electron microscope (TEM). An expansion of the lattice by nearly 5% was observed for the synthesized films in their low-thickness and as-deposited state. The lattice size approaches the bulk value when the film thickness increases or after vacuum annealing heat-treatment. The Ni4Al films have a nanocrystalline structure in which the ordered L12 phase appears upon annealing at above 500°C. A grain coalescence trend was found for the Ni4Al films during the in situ annealing above 500°C. This can be the main reason for the abnormal grain growth of these films at these high temperatures.
Translating OEE Measure into Manufacturing Sustainability
Authors: Wan Mahmood Wan Hasrulnizzam , Abdullah Ilyana , Md Fauadi Muhammad Hafidz Fazli
Published: May 2015

This paper focus on the translation of Overall Equipment Effectiveness (OEE) measure into manufacturing sustainability based on literature study. It examines the three OEE contributing factors; availability, performance, and quality; and the sustainable manufacturing components including environmental conservation, social efficiency, and economic enhancement. The OEE measure is not only possible to improve productivity through the identification and elimination of manufacturing major losses but its implementation has its own merits towards sustainable manufacturing. The findings can be used as an initial reference for manufacturers to consider OEE measure to advance the goal of manufacturing sustainability.
Simulation Study on Kenaf-Fibre Polyester Composite and LM6 Material
Authors: Mohd Nurul Farah Adibah , Sahroni Taufik Roni , Abd Kadir Mohammad Hafizudin
Published: May 2015

This paper present the investigation of sandwich model in the view of its properties. The objective of this paper is to define the mechanical properties of LM6 model and sandwich model. In recent years, researchers have viewed polymer matrix composite (PMC) as a potential material to increase the overall performance of materials for various type of field. This paper focused on the sandwich design by using metal material as the skin. The simulation study by using SolidWorks software is the simulation process used in this research to determine the stress, displacement and factor of safety of the design base. The purpose of design analysis in this paper is to prove the distribution data of simulation by indicating the maximum and minimum value of the design. In this research, LM6 materials used as the skin to introduced the kenaf-fibre composite in the sandwich design. LM6 is aluminium casting alloy which has tensile strength until 190MPa and its ductility properties enable to modify the shape by using casting process. The natural fibre has been used in this paper is kenaf-fibre due to its high tensile strength at 930MPa with 53GPa for the young modulus value. Two models are design for simulation study which is LM6 model and kenaf-fibre-LM6 model. These are to found out the characteristic between these two models.
Upgradable Design for Reduction of Production Cost and CO2 Emission - Case Study of a Laptop Computer
Authors: Yamada Shuho , Yamada Tetsuo , Bracke Stefan , Inoue Masato
Published: May 2015

An upgrade product design method is one of the efficient design methods for reducing environmental loads caused by mass production, consumption, and disposal. This method seeks to design a product that can adapt to future required performance and functions via component upgrade by exchanging components in the early phase of design. Because considerations of future product performance and functions include uncertain design information, an accurate prediction is very difficult. Therefore, this study defines uncertain design information as ranged sets, and applies a preference set-based design method that can correspondingly obtain ranged sets of design solutions. In previous studies, proposed methods were focused on product performance enhancement without quantitative consideration of environmental loads. Hence, this study proposes an upgrade product design method that can address the enhancement of product performance, while concurrently reducing production cost and environmental load, which is herein strictly defined as the amount of CO2 emission. Finally, our proposed upgrade product design method is applied to a laptop PC design problem to demonstrate its utility.
Development of E-Saving Glass by Malaysia Overview Using Quality Function Deployment Method for Market Transformation
Authors: Hamid Syaiful Rizal , Chew Boon Cheong , Abdullah Muhammad Azfar , Halim Sarah
Published: May 2015

This paper discusses the development of E-saving glass (ESG) in Malaysia by using quality function deployment (QFD) method for market transformation. This paper focuses on two objectives, i.e., (i) to investigate the suitability of the ESG in Malaysian market for customer satisfaction, product quality and manufacturer competitiveness by using systematic tools of QFD process, and (ii) the implementation of ESG by looking at factors analysis based on QFD method and Malaysian market transformation. The QFD method is utilised by a multidisciplinary team to translate a set of customer requirements (the “voice of customer” (VOC)), market research and technical benchmarking data into an appropriate number of prioritised engineering targets that could be met by a new product design.
Development of Jig for Sintering Hollow Tube Mat
Authors: Mohd Hadzley Abu Bakar , Izamshah R. , Amran Mohd , Azahar W.
Published: May 2015

This paper presents the development of a jig for sintering a hollow tube mat. The jig consisted of metal frames, clampers, rails and wheels that were assembled together to hold a stack of hollow tubes in a form of a honeycomb structure. The sintering process involved a large oven where the hollow tube was sintered up to 120°C within two hours. During the sintering process, a partial of plastic parts was melted to allow diffusion around the particle cores. A clamping force from the jig held the tubes to make sure that the molten region around the sintered tubes retained in contact. This gives the compact a sufficient strength to hold together as the heat was removed. The jig developed in this study was capable to produce a hollow cellular mat within the size of approximately 1m (width) x 1m (length) x 1m (height).
Psychophysical Experience and Heart Rate Analysis in Manual Lifting Task of Malaysian Population
Authors: Isa Halim , Rawaida O. , Syed Mohamed M.S. , Rohana A. , Nuradilah Z. , Hafiz Zani M. , Ahmad Fatihah Ros
Published: May 2015

Back pain is one of the prevalent injuries that occurs among Malaysian industrial workers. This is due to manual lifting task. Minimal studies have been conducted to determine the effects of manual lifting on psychophysical experience and heart rate of Malaysian population. The objective of this study is to analyze the psychophysical experience and heart rate of Malaysian in manual lifting task. The lifting task was experimented at various lifting heights (55 cm, 75 cm and 140 cm); loads with masses of 5 kg, 10 kg and 13 kg; and twist angles (0°, 45° and 90°). Six male and six female Malaysian students participated as subjects in the experiment. The Likert Scale was used to evaluate the psychophysical experience; meanwhile the heart rate monitor (Polar FT2, Finland) was applied to measure the heart rate. This study discovered that the psychophysical experience recorded the highest rating when performing lifting test at maximum load mass (13 kg), lifting height of 130 cm, and twist angle of 90°. Furthermore, the subjects experienced the highest heart rate after performing lifting test at maximum lifting height (130 cm) and load mass of 13 kg. This study concluded that the load mass, lifting height, and twist angle are proportional to the level of psychophysical experience. Additionally, when the load mass and lifting height were increased, the heart rate was also increased.
Design of an Ergonomic Acquisition and Monitoring Framework in Assembly Task
Authors: Zailan Zulfadli , Kamat Seri Rahayu , Rahman Muhamad Arfauz A. , Hashim Norhidayah , Roselaile Muhammad Eizzat , Abd Razak Mohd Norazlan
Published: May 2015

Optimum working conditions, such as body posture, body movement and working environment are commonly not directly known to the worker. In fact, the worker current working conditions are rarely provided. Although some may find it unnecessary, a mechanism to provide information on this situation is deemed to be useful. This paper presents a proposed framework for acquiring and monitoring ergonomic parameters. There are six potential useful parameters proposed in this study. The parameters include temperature, light, vibration, body posture, indoor air quality, and noise. In the proposed framework, the capturing device and signal converter are regarded as the main components. The framework is proposed to capture all parameters in the analog signal, and later convert it into the digital signal using the signal converter. At this stage, NI cDAQ-9188 is proposed to be used as the signal converter in the framework. The preliminary work of the proposed framework will be developed in the lab, while the implementation will be conducted at the chosen industry. It is hoped that the proposed framework will benefit industry and promote a safe working environment in the industry, especially for assembly tasks.
Influences of Body Position Selections on Knob Selections in Malaysian Manufacturing Industries
Authors: Tan Yue Hang , Ng Poh Kiat , Saptari Adi , Jee Kian Siong
Published: May 2015

Muscle fatigue and the development of hand-related musculoskeletal injuries can be caused by body positions that fail to accommodate control interfaces such as control knobs. There appear to be limited studies that investigate how different selections of body positions affect various selections of knobs, despite the fact that some articles have presented theoretical associations between different body positions and knob shapes. The goal of this paper is to determine the influences of body position selections on the knob selections of manual workers from several Malaysian manufacturing industries. A survey and observational studies were conducted, with over 70 responses collected for the survey and 79 responses collected for the observation. The survey responses were entered into Minitab 16 for the analysis, while the observation responses were sorted by frequency. The results show that the majority of the workers normally and preferably use the standing, seated and kneeling position for their manual work. The selections of the body positions that the workers assume also considerably affect the knob selections.
Roles of Pinch Grips in Different Knob Selections among Malaysian Manufacturing Workers
Authors: Tan Yue Hang , Ng Poh Kiat , Saptari Adi , Jee Kian Siong
Published: May 2015

The development of hand-related musculoskeletal injuries can be caused by pinch grips that fail to accommodate different control interfaces. One of the frequently used control interfaces in manufacturing industries is the knob. To date, there are limited statistical studies that investigate and support how different ways of executing pinch grips affect the selections of different knobs, even though there have been some studies theoretically suggesting a relation between different pinch grips and shapes of knobs. The purpose of this paper is to determine the roles of different pinch grips on the knob selections of a number of manual workers from Malaysian manufacturing firms. Regression analysis is used for this study. Survey responses were entered into Minitab 16 for analysis. The findings show that majority of the workers normally use the pulp pinch and lateral pinch, and prefer to use the lateral pinch for their manual tasks. The selection of these pinch grips also considerably affects the selection of the knobs that the workers control. The findings are valuable preliminary guidelines for identifying the ideal pinch grips that accommodate different knobs to potentially reduce hand-related injuries in Malaysian manufacturing industries.
Issues Surrounding Car Center Stack Designs in Malaysia: An Exploratory Study
Authors: Mohamed M.S.S. , Shamsul B.M.T , Rahman R. , Abdul Jalil Nawal Aswan
Published: May 2015

Car center stack designs have evolved rapidly throughout the years. Manufacturers are working hard in keeping up with the current trends in the automotive market by offering latest technologies embedded into car center stack designs. Consistent with the current trend, Malaysian automotive manufacturers are offering advanced features in car center stacks, which includes touchscreen and navigation systems. Recently car center stacks became the highlight as it became a potential source for driver distraction. An exploratory qualitative study, involving eight regular drivers and two professional drivers were recruited for this exploratory study. A laddering interview technique was applied to reveal chains of attributes, consequences and values. Several prominent attributes related to the value of safety were “Simple Design”, “Touchscreen”, “Meter Design”, and “Multi-Function Steering”. Touchscreen systems were perceived differently by professional drivers compared with regular drivers. There is a need for further studies regarding the touchscreen system designs for Malaysian drivers.
Warpage Analysis of Different Number Cooling Channels for Dumbbell Plastic Part in Injection Moulding
Authors: Amran Mohd , Salmah Siti , Izamshah Raja , Shahir Mohd , Amri Mohd , Mohamad Effendi , Sanusi Mohd , Sivaraos Sivaraos , Marjom Zolkarnain , Al-Amani Umar , Musa Mohd Kamal , Abdullah Zulkeflee
Published: May 2015

Warpage deflection is one of the common pitfalls in plastic injection moulding which is always affected the quality and accuracy of the plastic products. It occurs due to the influences of mould temperature during injection moulding process and it is related to the number of cooling system existed in the mould. Therefore, this paper studies the effect of cooling channels on warpage of dumbbell plastic part having different number of cooling channel using Moldflow software. Warpage analysis was run using four and eight cooling channels. Parameters involved in this study are injection time, packing time, melt temperature and mould temperature. The result of warpage from simulation analysis was projected on the graphic having different colour which is presented the actual value of warpage. It is found from warpage simulation result that the maximum warpage for four cooling channels is 1.283mm and the maximum warpage for eight cooling channels is 1.280mm. It shows that the increasing of the number of cooling channel from four to eight channels in the injection mould reduces the warpage deflection about 0.2%. Thus, the result shows that the number of cooling system in the mould plays an important role on the quality of plastic part during injection moulding process.
Cross-Industry Concurrent Engineering
Authors: Fukuda Shuichi
Published: May 2015

Concurrent Engineering (CE) has been discussed as a tool to reduce time to market in one company. In other words, CE was only discussed from the viewpoint of production time. But if we introduce the same idea of sharing knowledge not only across different processes in one company, but also to across different industries, i.e., if we develop cross-industry CE, we can not only reduce time and cost, but we can also make our production system more flexible. This paper describes the basic idea of cross-industry CE and its usefulness.
Voltage Source Inverter Fault Detection System Using Time Frequency Distribution
Authors: Ahmad Nur Sumayyah , Mustafa M. , Abdullah Abdul Rahim , Abidullah N.A. , Bahari Norhazilina
Published: May 2015

Open-switch and short-switch in a three-phase voltage source inverter (VSI) have a possibility to fault due to problems of switching devices.Any failure of the system in these applications may incur a cost and risk human live. Therefore, knowledgeon the fault mode behaviour of an inverter is extremely important from the standpoint of system design improvement, protection and fault detection. This paper presents detailed simulation results on condition monitoring and fault behaviour of VSI. The results obtained from the developed monitoring system allows user to identify the fault current. The developed system showed the capability in detecting the performance of VSI as well as identifying the characteristics of type of faults. This system provides a precaution and early detection of fault, thus reduces high maintenance cost and prevent critical fault from happening.
Geometric Accuracy Evaluation of Fabricated Parts by Additive Manufacturing toward Parallel Fabrication
Authors: Tateno Toshitake , Yaguchi Yuta , Hasegawa Osamu
Published: May 2015

Most rapid prototyping models are fabricated by additive manufacturing (AM) devices, which are usually called as 3D-printers. The AM models are expected to be used as practical parts for small batch manufacturing and maintenance parts supply. The main problem of AM for practical parts depends on processing accuracy and productivity. To compete with these problems, the parallel fabrication is considered. In this paper, after the concept of the parallel fabrication is introduced, the geometric accuracy of AM parts is evaluated and discussed from viewpoints of shape and processing. Two primitive shapes, which are a cube and a cylinder, are chosen as evaluation objects. These models are fabricated by two different type AM processing, which are Stereo Lithography (SL) and Fused Deposition Modeling (FDM). The geometry of objects is measured by a contact type 3D measurement system. As a result, characteristics of geometric error, which depend on shape features and AM processing, were found. The design guideline for contact surfaces between segmented parts is discussed.
Scalable Electrical Model and Performance Analysis of a Novel Bar TSV Structure
Authors: Li Zhen Song , Miao Min , Yang Shao Chun , Yang Da Cheng
Published: May 2015

A novel Bar TSV(B-TSV) structure, formed by two semi-cylinders combining with a quadrangular is studied in this paper. This B-TSV structure extends the TSV design options by introducing new design parameters. The scalable electrical model of B-TSV is proposed and the effects of design parameters, such as the side length of quadrangular and the minimum distance between TSVs are investigated and concluded by a 3D electromagnetic solver. Performance comparison between B-TSV and the traditional cylindrical one is also provided by simulation under the Ground-Signal-Ground configuration. Simulation results show that B-TSV has better performance than the traditional one, and can be used to increase the TSV array density without degrading the electrical performance of TSV system.
Experimental Investigation of Thermal Conduction Performance on Silicon-Based Micro Flat Heat Pipe
Authors: Li Cong Ming , Luo Yi , Zhou Chuan Peng , Zou Liang Liang , Wang Xiao Dong , Shan Qing
Published: May 2015

There are several factors that affect heat transfer of heat pipe, for example, structure dimension, filling ratio and vacuum degree of charging. This paper studied the thermal conductivity of micro flat heat pipes (MFHPs) with different structure dimension and with different filling ratio, when the charging vacuum degree of MFHP was decided. When electric power was 2W or 4W, MFHPs with parallel grooves and nonparallel grooves, charged by working fluid with different filling ratio, were carried out. And the filling ratio is 30%, 40% and 50%, respectively. The better thermal performance of MFHP can be evaluated by lower thermal resistance and higher effective thermal conductivity. The experiment results show that MFHP has the highest effective thermal conductivity when the filling ratio is 40%; and the thermal performance of MFHP with nonparallel structure in axial direction is better than that of MFHP with parallel structure.
Analysis of Effective Field Emitting Angle for Spindt Cathode
Authors: Li Nan Nan , Pang Shu Cai , Yan Fei , Jin Da Zhi , Xiang Wei , Zhang De , Dai Jin Yi , Zeng Bao Qing
Published: May 2015

Effective field emitting angle plays an important role when investigating field emission characters. In this work, effective field emitting angle is introduced for Spindt-type emitter to relate spatial variation of current density along tip’s surface to emission current. The effects of various parameters on effective field emitting angle are analyzed. The results show that effective field emitting angle decreases exponentially as half angle increases, decreases quadratically as radius of gate aperture increases, but increases logarithmically as gate voltage increases linearly. It is also found that effective field emitting angle increases first and then decreases with emitter’s height increasing. Similar trends can be also found with insulator height. Grid thickness nearly has no effect on the effective field emitting angle.
Design and Experiment of Phase Laser Ranging System Based on MEMS Mirror for Scanning Detection
Authors: Zhang Chi , Huang Hu
Published: May 2015

A laser ranging system for scanning detection based on phase shift ranging technology and a MEMS mirror for space detection and measurement is presented in this paper. The laser ranging system is mainly composed of a modulation module, a laser, a MEMS mirror, a photo-electric conversion module and a signal processing module. The phase shift ranging method is used to measure the relative range to the target. The MEMS mirror is a micro scanner with two DOF, which is used to change the direction of the emitted laser beam. The modulated laser beam is emitted through the MEMS mirror and reflected from the target. The relative range is calculated by the phase shift between the emitted beam and the reflected beam. The experimental results indicate that the measurement accuracy is 0.10 m in static status and 0.17 m in scanning status in the range of 3 m. The differences between the static and the scanning status are analyzed and improvements are proposed.
High Performance Supercapacitor Electrode Materials Based on Activated Carbon and Conducting Polypyrrole
Authors: Yuan Wen Tao , Yang Ya Jie , Qiu Yong Long , Xu Jian Hua , Yang Wen Yao , Xia Shuang
Published: May 2015

The traditional supercapacitor is made of activated carbon, which shows lower specific capacity and higher resistance. In this paper, we demonstrated preparation of high performance supercapacitor electrode materials based on activated carbon and conducting polymer polypyrrole (ppy). In order to obtain well dispersion of ppy in activated carbon for lower resistance of electrode, a high-speed agate beads milling process was used to mix the ppy and porous carbon powder. By controlling the synergistic effect between ppy and activated carbon, a uniform structure composite electrode was prepared and the performance of this composite based supercapacitor was investigated. Compared with pure activated electrode, the obvious electrochemical performance improvement was achieved in composite electrode after the introduction of ppy. It has been found that electrode based on this composite has a maximum specific capacitance about 159 F/g, which was higher than pure activated carbon, and exhibited low resistance about 3.35 Ohm. The cycle performance results revealed that a 142 F/g (more than 88% of initial capacitance) capacitance was kept in composite electrode after 1000 cycles charge/discharge process. We conclude that the excellent synergistic effect between activated carbon and ppy resulted in superior electrochemical performance of composite electrode. Furthermore, the simple preparing method of composite electrode for supercapacitor assembly has potential commercial applications.
Secondary Synthesis of Microporous Heteroatoms Y Zeolite and their Hydrodesulfurization Properties for Model Fuel
Authors: Hong Xin , Tang Ke
Published: May 2015

Gallium atoms have been introduced into the framework of Y zeolite by treating the zeolite with an aqueous solution of ammonium hexafluoro gallate. The synthesized Y zeolite ([Ga]AlY) was characterized by means of X-Ray Diffraction (XRD), N2 adsorption, Infrared spectrophotometer (IR) and Inductively Coupled Plasma (ICP). The results indicated that Ga has been substituted into the faujasitic framework. Hydrodesulfurization (HDS) of various model fuels containing about 500 μg/g sulfur has been studied over the [Ga]AlY. The activity of the [Ga]AlY catalysts on HDS reaction is highly affected by the temperature and kind of sulfide in model fuels. The conversion for thiophene, benzothiophene (BT) and dibenzothiophene (DBT) in model fuel 1, 2 or 3 was 81.2%, 60.7% and 37.2% respectively. Compared with the model fuel 1, 2 and 3, the conversion of every sulfide in model fuel 4 was much lower which can be due to the competitive adsorption between between the three of them.
Design and Comparison of Micro Electromagnetic Vibration Energy Harvesters
Authors: Lei Yi Ming , Wen Zhi Yu , Chen Li
Published: May 2015

This paper presents two electromagnetic vibration energy harvesters based on micro-electro-mechanical (MEMS) technology. Two prototypes with different vibration structures were designed and fabricated. The energy harvester includes a permanent magnet attached on vibration structure (resonator) made by Si and a fixed wire-wound coil, with the total volume of 0.9 cm3. Two energy harvesters with different resonator are tested and compared. Experiments show that: in the same acceleration and a load resistance, the resonant frequency of prototype B is approximately 95% of prototype A; The peak-peak voltage and the maximum power of prototype B is 1.6 times and 2.7 times of prototype A respectively. The test results was analyzed simply and it indicated that the electromagnetic energy harvesting with the spring B has better performance; also proved that the potential ability of the non-linear spring could extend the frequency bandwidth and improve output voltage.
Enrichment Efficiency Optimization of Dielectrophoresis Cell Chip Based on Interdigitated Microelectrodes Array
Authors: Gu Wen Wen , Huang Jie
Published: May 2015

At present, the majority dielectrophoresis chip designs optimize their performance by electric simulation and fluid field simulation. The lack of further cells force analysis and movement prediction results in a limited cell dielectrophoresis enrichment efficiency. The HepG2 hepatoma carcinoma cell movement under the action of dielectrophoresis force, fluid force and gravity was analyzed respectively by Comsol Multiphysics software. The preliminary optimization conditions for the cell enrichment were obtained. According to the simulation results, the experiments were carried out to investigate the enrichment effect of the HepG2 hepatoma carcinoma cells. The experiment result demonstrated the enrichment efficiency of HepG2 hepatoma carcinoma cells was reached to 88.89% under the 5 V amplitude and 4 MHz frequency sinusoidal signal excitation.
Functionalization of Mesoporous SBA-15 with APTES by Co-Condensation and its Effect on Immobilization of Candida rugosa Lipase
Authors: Li Xiu Yan , Xu Yun Qiang , Zhou Guo Wei
Published: May 2015

Functionalized SBA-15 with mesoscopic pore channels was synthesized by co-condensation of tetraethoxysilane and (3-aminopropyl) triethoxysilane (APTES) via hydrothermal process. Small-angle X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy were used to monitor the effect of surface functionalization on the structural and textural features of the SBA-15. The results suggested that the structural ordering of functionalized SBA-15, as well as pore diameters, pore volumes and surface areas, were decreased with increasing the APTES molar ratio. Candida rugosa lipase (CRL) was used as a model enzyme for studying the effect of amino-functionalized on loading amount and enzymatic activity. The effects of pH and temperature on catalytic hydrolysis of tributyrin by immobilized CRL were investigated. The results showed that immobilized CRL had a well adaptability in a wide pH and temperature region, and CRL immobilized on functionalized SBA-15 exhibited much higher enzymatic activity than free CRL, especially, 5 mol% APTES functionalized SBA-15 immobilized CRL displayed the highest activity.
A CMOS Automatic Gain Control Circuit for Biomedical Applications
Authors: Gao Zhi Qiang , Huang Fu Xiang , Li Jing , Yin Liang , Liu Xiao Wei
Published: May 2015

In this paper, a low-voltage automatic gain control (AGC) circuits is presented. The proposed circuit uses a novel approximated exponential function to increase the dB-linear output range. The three-stage AGC is fabricated in 0.18μm CMOS technology and shows the maximum gain variation of more than 100dB and a 67dB linear range with linearity error of less than ±1dB. The range of gain variation can be controlled from 34 to 101dB. The AGC dissipates less than 2.3mA under 1.8V supply voltage while occupying 0.4mm2 of chip area.
Expansion Performance of Novel Balloon-Expandable Stent for Tapered Vessel
Authors: Shen Xiang , Sun Yang Yang , Wu Bo Bo
Published: May 2015

In-stent restenosis still remains an obsession to cardiologist, especially in tapered vessels. In this paper, we designed a novel balloon-expandable stent for tapered vessel and proposed a finite element method (FEM) to study the expansion of the novel stent. The effect of stent design parameters on stent tapering and foreshortening were also researched. Results show that the radial displacement of stent proximal end was always larger than that of stent distal end during stent expansion, and the stent had a tapered shape as a whole after expansion. The degree of stent tapering observed increased with the expansion pressure increase. Besides, increasing the gradient of ring amplitude not only could increase the tapering degree of stent after expansion, but also could decrease stent foreshortening, improving the positioning accuracy after stent implantation. In conclusion, FEM can quantify expansion performance of novel balloon-expandable stents and help designers to devise and assess new stent designs for tapered vessel.
Simulation and Test of through Silicon Vias Impacted by Large Current Pulse
Authors: Ding Xu Ran , Wang Ya Bin , Lou Wen Zhong , Liu Fang Yi
Published: May 2015

The failure mechanism of through silicon vias impacted by large current pulse is reported. A theoretical model has been built to describe how TSVs fails when impacted by large current pulse. The theoretical model is then solved by applying COMSOL Multiphysics and the weak points of the TSV have been pointed out. By applying the large current pulse generating and testing system, an experiment has been done to verify the theoretical model. The results show that although the TSVs may be broken down when impacted by large current pulse, it can still be function by using several TSVs in parallel.
Research on TSV Dry Etching Technology
Authors: Jiang Guo Qing , Kuang Lei , Zhu Jian
Published: May 2015

TSV is a new technology to make interconnections between chips by creating vertical wafer-to-wafer vias. The application of ICP ( inductively coupled plasma ) dry etching to make TSV is discussed in this paper. Starting with hardware conditions of the equipment, a large number of experiments were conducted to test the process parameters combining with the fundamentals of dry etching. By constantly modifying the parameters to optimize the process, a final result of TSV with the width of 2.62um, depth of 63.5um, verticality of 89.8°and scallop of 70.3nm was realized in this paper.
Intermolecular-Interaction and Mechanical Properties of MNs-Plasticizer Modified 2,4,6-Trinitrotoluene/1,3,5-Trinitrohexahydro-1,3,5-Triazine Molten-Energetic-Composite(MEC)
Authors: Ma Qing , Wen Mao Ping , Zheng Bao Hui , Huang Heng Jian , Liu Da Bin , Li Jin Shan
Published: May 2015

Intermolecular interaction of mononitrotoluenes (MNs) plasticizer with 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrohexahydro-1,3,5-triazine (RDX) was experimentally and theoretically investigated. The basis set superposition error (BSSE) and interaction energy of TNT, RDX and plasticizers were computed at MP2/6-311++G** levels. Compared with the weak Einterbetween RDX and TNT (−1.586 kJ/mol), Einterbetween the o-nitrotoluene and TNT and RDX can increase to −131.557 kJ/mol and −48.487 kJ/mol, indicating there is strong intermolecular-interaction. SEM imagines also show that mononitrotoluene could form layered deposits in TNT and closely surround RDX crystalline. MD simulation results indicate that tensile modulus of (100) TNT and (100) RDX increases when introducing mononitrotoluene plasticizers separately, which agree with the experimental phenomenon of Brazilian disk test.
Research Survey of Electroformed Nickel Material Properties Used in MEMS
Authors: Li Guo Zhong , Shi Geng Chen , Sui Li , Yi Fu Ting , Wang Bo
Published: May 2015

As one of the significant structural materials used in safe and arming system of MEMS fuze, the research on micro-electroforming process technologies and micro-electroforming nickel’s properties have been a popular field for MEMS area. This paper surveys present domestic and overseas research status of mechanical characterization of electroformed nickel, summarizes and analyzes that changes of the microstructure led by parameters of micro-electroforming process and the external environment make great effects.
Optimization of Chemical Mechanical Planarization Process of High Enrichment Slurry Under Low Pressure
Authors: Li Yan , Liu Yu Ling , Li Hong Bo , Wang Ao Chen , Liu Wei Juan , Hong Jiao
Published: May 2015

The polishing process was optimized according to the polishing rate and its consistency of HE slurry with different dilution multiple on the copper wafers, it can be confirmed that: the best pressure value of HE1, HE10, HE20, HE50 type slurries was 6890Pa, the best flow rate value of the preceding three slurries was 300ml/min, the best value of the HE50 slurry was 400ml/min. Through the planarization effects of the slurries with different dilution multiple, it can be obtained that: the initial dishing and erosion heights of the samples were both 1270nm and -500nm, and the two values respectively changed to 539.3nm, -75.7nm and 796.3nm, -191.3nm after being treated by HE1 and HE10 slurries, the step height of the wafer changed from 117nm to 72nm after being treated by HE20 slurry, the step height of the wafer changed from 88nm to 71nm after being treated by HE50 slurry. It was concluded that: the HE slurry shows strong ability for step removal when the slurry is diluted by 1 times and 10 times, the HE slurry also owns high planarization ability when the slurry is diluted by 20 times and 50 times.
Synthesis and Characterization of Topological Insulator Bi2Te3 Nanowires
Authors: Guo Zhen , Lu Lan , Wang Jing Yun , Xing Ying Jie
Published: May 2015

Bi2Te3 nanowires are prepared by a low-cost and facile hydrothermal method without any surfactant. The structure and morphology of the nanowires are characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscope. The influences of experimental conditions on the products are investigated. The growth mechanism is proposed based on the experimental results. This work is promising for the synthesis of Bi2Te3 nanowires with less impurity.
Fabrication of Ultrasmooth Polymer Films by Concentration Control and Spin Speed Adjustment
Authors: Guo Yan , Liu Wei Guo , Liu Huan , Zhou Shun , Wu Lei , Li Fei
Published: May 2015

In order to obtain ultrasmooth polymer films, in combination with sacrificial layer a variety of impending structures in MEMS devices can be easily prepared. Two methods using polymer concentration control and spin speed adjustment to planarize polymer surface are presented. The influence of polymer concentration and spin speed on the effect of photoresist planarization is studied on. Through a large number of experiments, optimized process parameters are collected. It is found that the roughness was reduced effectively when the spin high speed was 5000rpm for 50 seconds under the condition of volume dilution ratio of 1:5. This process is able to produce a smooth surface structure.
UV Photocatalytic Digestion Utilizing TiO2 Nano-Fiber for the Determination of Total Phosphorus
Authors: Zhang Qiang , Tong Jian Hua , Bian Chao , Xia Shan Hong
Published: May 2015

This paper describes the fabrication, characterization and the application of the photocatalytic TiO2nanofiber as the photocatalyst for the digestion of total phosphorus (TP). The nanoTiO2fibers were fabricated by the electro-spinning technique on silicon substrate. Under the conditions of room temperature (25 degrees Celsius) and humidity less than 40%, the TiO2fabricated by the electro-spinning presents a silky coagulation appearance, which can be converted to the nanofiber appearance by annealed in the muffle furnace at 450 degrees Celsius for 10 hours. X-ray diffraction (XRD) examination shows that the silky coagulation can be converted to anatase-type TiO2. The absorbance values of different phosphate concentrations after exposure in UV light at the intensity of 7000μW/cm2were tested in this paper. Sodium tripolyphosphate solutions serve as the water sample of TP, and five standard concentrations (by weight of P) are 0.0mg/L, 1.0mg/L, 2.0mg/L,3.0mg/L and 4.0mg/L, respectively. The digestion rate exhibits satisfied linearity ranges from 0.0mg/L to 4.0mg/L with acceptable linearity R2of calibration curve, in both digestion temperature of 25 degrees Celsius and 50 degrees Celsius.