bluuebunny/crossref_metadata_2025 huggingface dataset:
Defect and Position Measurement of Pipeline Inner Surface Defects
Authors: Bai Su Ping , Jiang Hai Yang , Zhu Zhong Yao
Published: May 2013

The paper aims to measure the exact position while detecting inner surface defects of large scale pipeline. A realizable method using opto-electrical is presented in this paper, which can give the position of opto-electrical sensor. On-line measured data is automatically recorded and processed with precision because of the application of step motor and gear drive, as well as software controlling computer.
Dynamic Focus-Position Detection Technique with Array Camera in Long Focal Length System
Authors: Zhao Juan Ning , Dong Xiao Na , Da Zheng Sheng , Li Hong Guang
Published: May 2013

A precise detection technique with array camera is discussed for the detection of dynamic focus position in this paper. This technique is well applicable for measuring the focal spot shifting of large and slow lens or optical systems. Two coated wedges are adopted in light path to supply bands of beams, which form the spots matrix on the detector. Focus position shifting can be indirectly obtained from position shifting of the smallest spot on the detector. The technology discussed here is simple and accurate; it also solves the problem that dynamical focal spot position shifting is immeasurable for conventional focal length measureing methods.
Excitation and Receiving Circuit Design for the Multi-Element Medical Ultrasonic Endoscope Probe
Authors: Li Zhong Yi , Chen Xiao Dong , Hao Yun Xia , Yu Dao Yin
Published: May 2013

Multi-element ultrasonic probe applied in vivo, compared with the traditional probe applied in vitro or single-element probe, has its own specialty in working environment and structure. This paper designed an analog circuit applied in vivo including excitation and reception amplification for multi-element ultrasonic probe. The circuit provides an excitation and receiving front-end for the self-developed multi-element ultrasound endoscope imaging system. This ultrasound analog circuit can be used for d / 2 ultrasonic scanning along with the 16 element ultrasound transducer.
A Precise MTF Measurement Method of Programmable Optical Systems
Authors: Song Yu Long
Published: May 2013

The programmable coded aperture has been applied to the optical systems to enhance their functionality and performance. Therefore, the optical system is programmable. It means that the optical system could be changed momentarily. Conventionally, during MTF measurement, the optical system is fixed. The system under test and the test equipment have no relation of time- sequence. The image sensor sample of test equipment can be random. But In the programmable optical system, the aperture style and its duration in a frame period have a impact on the system MTF. Conventional MTF measurement methods can’t be used to test accurately the MTF of programmable optical system. In this paper, we propose a method and design a system which can test precisely MTF of the programmable optical system. In this method the sample of a sensor would be synchronized with the coded aperture program logic, which ensures the precision of MTF measurement.
Two Methods to Loosen Optical Manufacture Tolerances for ArF Projection Optics
Authors: Liu Xiao Lin , Li Yan Qiu , Liu Ke , Wei Li Dong
Published: May 2013

Small field ArF projection optics for experiment is favorable to the prospective study and key technique development for lithography equipment. An ArF projection optics has been designed with specifications of 0.75 numerical aperture (NA), 100μm image field of view and 40X reduction ratio. The designed composite root-mean-square (RMS) of wave front error of the system can reach 0.03λ (λ=193.29nm). To achieve diffraction limited resolution, the optical manufacture tolerances of this high-NA projection optics are too tight to manufacture, such as radius error within ±0.01%, central thickness within ±2μm and surface figure error less than peak-valley (P-V) of 1/30λ (λ=632.8nm). In this paper, two effective compensatory methods are presented to relax the manufacture tolerances before assembly. One method is re-computation of air spaces including actual measured values of the radii of curvature and center thickness for each element. The second method is rotating lenses to find the best matching manner of measured surface figure. The results show that radius error, central thickness error and surface figure error can be compensated significantly，and the best performance of the projection optics disregarding assembly error has been acquired. The composite wave front error RMS can reach 0.09λ (λ=193.29 nm) after compensation, which is much smaller than 0.25λ before compensation under the same optical manufacture error. Both methods can also be used in development of industrial lithographic projection optics.
Deformation Measurement Method for Artillery Components Based on Laser Radar
Authors: Tang Wei , Niu Jin , Wan Jia Qing , Ning Ping , Li Dian
Published: May 2013

It is difficult to measure deformation for artillery components accurately without disassembly since these components have complex structures and large dimensions. A new deformation measurement method for artillery components is introduced in this paper based on laser radar. Test data proves that laser radar’s measurement accuracy can satisfy the requirement of artillery’s approval test.
Research on Measurement Method of Parallelism of Artillery’s Directional Beam Based on the Laser Radar
Authors: Tang Wei , Zhang Xin Ting , Zhao Li Chao , Guan Shi Sheng , Jiang Ming Yi
Published: May 2013

As the increasingly improvement of modern weapons and detection technique, it is proposed that a higher demand on firing accuracy of artillery and bullet spread, and the parallelism of artillery’s directional beam was one of the important factors. The article conducted a research on the measuring methods of the parallelism of artillery’s directional beam. After concluding its shortcomings, a method of parallelism of artillery’s directional beam based on the laser radar was put forward by laser radar to detect the parallelism of artillery’s directional beam. The experimental results shown that the method can reach the detection accuracy of 0.2 mils, realize the high accuracy and high efficiency measurement.
The Design of Optomechanical for Bear Severe Mechanics Environment
Authors: Yang Hong Tao , Fan Zhe Yuan , Chen Wei Ning , Zhang Zhao Hui , Zhang Jian , Zhang Zhi
Published: May 2013

Optical lenses act as the important methods for acquire the image information is applied increasingly board ,In accordance with the application environment that require content the precision and the force environment adaptation yet more power, so it is necessary that research on the adaption ability to the big level vibration and shock. In order to stand the bitter force environment put to use the centering assembly technology to ensure the image quality of the optical system. Design the different damping coefficient rubber-bearing isolation that assimilate the big level shock energy. At first, by the Pro/e software establish the three-dimensional model and use the ANSYS software simulate and analysis the result of the design. We want to apple the Sigfit software to simulate the effect that the vibration and shock affect on the MTF of the optical system. After optimize the design theory so as to attain the optimized result. By the experiment test the lenses about the accommodate ability, the result which can meet the shock of5000g.and 20g random vibration, camera can work effectively. This kind of design technology is mature and reliable and live through the examination under all kinds of environment, this design method is provided the reference for the design and development of optical mechanism production.
Optical Correlation Recognition Research of Low Light Level Target Based on Lifting Wavelet Transform
Authors: Zhang Qi Bo , Zhang Su , Zhang Yu , Wang Wen Sheng
Published: May 2013

Optical correlation technology is an important application in target recognition field, which can apply Joint Transform Correlator (JTC) to achieve target recognition. For the Low Light Level (LLL) target with low contrast and background noise interference, using optical correlation method may reduce the recognition ratio. In order to solve the problem, an effective algorithm-adaptive directional lifting based on wavelet transform (ADL) is used to process LLL target image. LLL image enhancement and target edge extraction are applied in this algorithm. Experimental results show that this algorithm can enhance the brightness of the correlation peaks and has the advantage of quick operation.
Fast Tracking of Moving Target Combining SURF and Cluster Analysis
Authors: Li Ying , Yu Jing Jiang , Fu Yue Gang , Xu Zheng Ping , Zhou Xun
Published: May 2013

In order to design a moving target fast tracking system with respect to a real-time and stable tracking process, especially when the shape of moving target or its environment condition changes, a new algorithm named SURF-KMs is proposed. SURF-KMs combines the advantages of SURF algorithm with a cluster analysis of K-means method. First, feature points are collected and then they generate the matching template vectors based on the SURF algorithm. Second, the feature points and the center of the target are estimated by using the K-means method to determine the target’s cluster scope and update the tracking window. Finally, a self-adapting updating strategy for matching template is also proposed in order to track moving target automatically. Experimental results indicate that SURF-KMs is mostly able to achieve a stable tracking while with the monitored target rotating, scale changing, and also the environment illumination glittering. Moreover, it can satisfy the system requirements of tracking stability, higher precision and anti-jamming.
Structure Design and Finite Element Analysis of Receiving System for Optical Communication
Authors: Liu Shu Bin , Gao Tian Yuan , Wu Ya Bo
Published: May 2013

Along with the rapid development of science and technology, and due to the special advantage of laser communication, such as big traffic and good secrecy, the application of optical communication is more and more wide. One of key technologies is the structure design of receiving system. In this paper, a structure of receiving system for optical communication based on Cassegrain system is introduced. Consist of the support structure of primary mirror and secondary mirror, adjustment structure of secondary mirror, structure design of reflectors, etc. FEM is used to analyze the distortion of primary mirror which is based on this structure. The distortion is caused by pressure, self-weight and temperature change, etc. And the stress deformation of primary mirror tube is analysed particularly. Analysis and test results demonstrate that the design project is reasonable.
On-Machine Measurementand Characterization of V-Groove Structure Pattern on Precision Rollers
Authors: Cheung Chi Fai , Ren Ming Jun , Li Da , Kong Ling Bao , To Suet , Li Ji Bin
Published: May 2013

Rolling Imprint Lithography is an Enabling Technique for the Mass Production of Ultra-Precision Micro-Structured Surfaces which are Widely Used in High Value Added Optical Products such as Backlight Guides for Display Devices. the Accuracy of the Produced Micro-Structured Surfaces Relies Heavily on the Master Roller of which Quality is Difficult to be Controlled by Traditional Off-Line Measurement Process due to the Large Dimension and Heavy Weight of the Workpiece. this Paper Presents a CCD Based Non-Contact Measurement System to Perform the on-Machine Measurement of the Structure Pattern on Machined Rollers. Instead of Measuring each Single Structure on the Roller, the System is more Focused on the Characterization of the Conformance of the Structure Pattern with the Designer’s Requirement. Low Angle Monochromatic Light is Used to Extract the Structure Pattern on the Machined Roller Using a High Magnification Objective Lens with a High Resolution CCD Sensor. the Image Processing Techniques are then Employed to Characterize the Captured Image Based on the Designed Pattern Structure. the Developed System has been Mounted on a Single-Point Diamond Turning Machine to Measure the Machined Structured Roller, and the Results Indicate that the Developed Measurement System is Able to Perform the on-Machine Measurement and Characterization of the Structure Pattern of the Machined Roller with Sub-Micrometre Accuracy.
Athermal Design of Infrared Telephoto Used in Joint Transform Correlator
Authors: Dong Jia Ning , Mu Da , Xu Chun Yun
Published: May 2013

On the basis of optical correlation detection, joint transform correlator(JTC) is widely used in military, aviation and intelligentization and so on. It has the advantages of great flexibility and high precision of recognition. The optical system is applied to receive the infrared radiation of the target. Athermalization is the key to stabilizing the optical performance with respect to off-design temperature. Therefore, the image quality of optical system in different temperatures plays an important role in JTC. In order to improve the environmental adaptability of JTC, the infrared telephoto system with high image quality and high performance-price ratio is designed for wavelength 8μm～12μm to detect target in a large range of temperature. This telephoto lens is composed of four refractive lenses. Three materials, zinc selenide, germanium and zinc sulfide are used to compensate for the temperature. The focal length is 200 mm, the relative aperture is 1:3, and the field of view is 6.4°. This system has the characteristics of small volume and compact structure. The optical system image quality is evaluated with ZEMAX optical design software. The results have shown that MTFs in the range of -40°C to +60°C are all closed to the diffraction limited curve. The spot diagram RMS radius of each field is closed to the Airy disk radius. The system meets the requirements of technical specification and improves the ability of JTC in target tracking and recognition.
A Study of Effect of Cutting Strategy on Surface Generation in Ultra-Precision Machining of Micro-Structured Pattern Rollers
Authors: Kong L.B. , Mak C.H. , Cheung C.F. , Lee Wing Bun , To S. , Ho W.K.
Published: May 2013

Plasticfilms with Embossed Micro-Structured Patterns have been Widely Used Inbacklight Guide Panels. the Mass Production of these Films Demands Forultra-Precision Roller Embossing of Micro-Structured Patterns on Plastic Filmsby Precision Pattern Rollers. due to the Heavy Workload and High Precisionrequirements, Ultra-Precision Rollers with Microstructures are very Difficultto be Machined in the Level of Submicrometer Form Accuracy and Surface Finishin Nanometer Range. this Paper Presents Theoretical and Experimental Studies Ofultra-Precision Machining of Precision Rollers with Microstructures. Themachining Mechanism for Precision Roller is Firstly Explained, and Hence Astudy of Effect of Cutting Strategies on Surface Generation in Ultra-Precisionmachining of Micro-Structured Pattern Rollers is Presented. this Includes Thestudy of Different Cutting Trajectories, Length-to-Diameter Ratio of Therollers, Mounting Method for the Rollers, the Number of Cuts in the Formationof the Micro-Structured Patterns, as well as the Time Budgeting for Adoptingdifferent Cutting Trajectories in Ultra-Precision Machining of Micro-Structuredpattern Rollers. the Results of the Study Provide an Important Means Forenhancing the Surface Quality and Optimizing the Time for Machining Precisionrollers.
The Structural Design Method of Multi-Layer Parabolic Reflective Surface for X-Ray Focusing
Authors: Ouyang Miang Zhao , Fu Yue Gang , Liu Zhi Ying , Wang Jia Ke , He Wen Jun
Published: May 2013

As an ultra-short electromagnetic waves, X-ray has a strong ability to penetrate with high-energy. The method for focusing visible spectral bands is not suitable for X-ray spectrum. At present, in X-ray astronomy, the X-ray focus mode which uses grazing incidence less than critical angle has been widely used. However, the small critical angle limits its effective aperture of the X-ray collection. This paper presents a multi-layer reflective structure working with grazing incidence and the surfaces coated multilayer high reflective for X-ray. It can guarantee the large effective entrance pupil and high energy collection. The 200mm diameter X-ray focusing device is designed as an example. It is found from simulation that a good focusing result is acquired.
Design of Athermalized Infrared Telephoto Lens
Authors: Zhang Yu , Shang Ji Yang , Xu Yue , Wang Wen Sheng
Published: May 2013

IR optical system is much more appropriate to be applied in cluttered and formidable conditions. The change of temperature could degrade image quality of the infrared optical system. So the athermalization becomes the difficult part and key factor in the designing of MWIR optical systems for working under temperature range of -40°C~60°C. In this paper, the infrared telephoto lens is designed; it meets the designing requirements and has good image quality. The effective focal length is 240mm and the F-number is 2.The full field of view is 3.2°. In order to balance the chromatic aberration, an aspherical surface is used in the athermalized infrared optical system. Through carefully selected optical material and reasonable optical power distribution, passive optical athermalization can be realized. The curve of MTF is close to diffraction limit. Within the working temperature, the value of MTF at 30cy/mm is always large than 0.6. The results show that the modulation transfer function (MTF) of optical system in all field of view approaches the diffraction limit at different temperature, and 80% energy concentrates in 1 pixel.
Mechanical Passive Compensation for Athermalisation Design of Infrared Optical System
Authors: Zhang Zhi , Zhang Zhao Hui , Fan Zhe Yuan , Yan Aqi , Zhang Jian , Yang Hong Tao , Cao Jian Zhong
Published: May 2013

Optical equipments especially those for aerospace application are expected to work over a wide temperature range. The change of temperature could cause the refractive index change of infrared glass elements. Furthermore, it would lead to the defocus of the image surface and the performance degradation, so the method of temperature compensation must be adopted, which could make sure that optical system would adapt to the change of ambient temperature. A method of temperature compensation with mechanical passive compensation is briefly described, and an example is also given. The quality of image could be optimized through mechanical passive compensation,depending on the differences of metal and non-metallic thermal expansion coefficient. The results show that the optical system works stablely in the designed temperature range. It is of great importance to the athermalisation design of infrared optical system.
Optical Design of Zoom Hyper Spectral System
Authors: Liu Zhi Ying , Cui Cheng Jun , Song Yu Long
Published: May 2013

Hyper spectral imaging technology is widely applied in military scout and target recognition with imaging and spectral integration. To acquire different size image and field of view, a kind of zoom hyper spectral optical system is designed in this paper. The working spectrum is from 400nm to 1000nm. The detector size is 6.4mm×4.8mm. F# is from 3.5 to 5.6, and the focal length is from 28mm to 80mm. With consideration of the reasonable MTF requirement of back relay system and the visibility threshold of human eyes, which is the final receiver, the design requirements are analyzed. The initial structure is acquired by zoom method. After optimization, the image quality of every focal length and every spectrum meets the analyzed requirements. At last, to ensure the stable image during zoom process, the cam curve is calculated with image stable theory of dynamic optics.
Green Synthesis of Silver Nanoparticles Using Aqueous Floral Extract of Nelumbo Nucifera
Authors: Arokiyaraj Selvaraj , Nyayiru Kannaian Udaya Prakash , Elakkya Vijay , Kamala T. , Bhuvaneswari S. , Dinesh Kumar V.
Published: May 2013

The aim of the present study is to synthesize silver nanoparticles, using an aqueous floral extract of common Lotus, i.e Nelumbo nucifera. The synthesized nanoparticles were characterized using UV, TEM, EDX, AFM & XRD. The synthesized AgNPs were confirmed due to the colour change from colourless to reddish brown just after the addition of the aqueous floral extract of Nelumbo nucifera. The UV results of AgNPs showed the excitation of surface Plasmon resonance band at 427 nm. TEM results showed that the synthesized AgNPs were uniformed; monodispersed,spherical in shape and the particle size were found to be 77.81 ± 3.54 nm. EDX spectrum of AgNPs confirms strong signals from Ag (64%) and other elements such as C, O and Cl. The morphology of the synthesized AgNPs by AFM analysis resembled the TEM micrograph. The crystalline nature of the AgNPs was confirmed by XRD. The present study concludes that the aqueous floral extract of Nelumbo nucifera could be used as an effective reducing agent for the synthesis of AgNP. The green synthesis ofsilver nanoparticles is non-toxic and cost-effective and thus remains to be an alternative method to other physical and chemical reduction methods.
Kinetics Transformation of Anatase to Rutile Phase for Titanium Dioxide Nanoparticles Prepared by Sol-Gel Method
Authors: Ba-Abbad Muneer M. , Kadhum Abdul Amir Hassan , Mohamad Abu Bakar , Takriff Mohd Sobri , Sopian Kamaruzzaman , Al-Shamali Salmin S.
Published: May 2013

Simple sol-gel route was used to synthesis the TiO2nanoparticles and examined by X-ray diffraction (XRD). The small particle size and uniform morphology of the TiO2were found at different calcination temperatures. The kinetic study of phase changes from the anatase to rutile using the X-ray diffraction data with Avrami equation was investigated. The transformation of anatase to rutile was started after 500 °C and above by decreasing of XRD peaks intensity of anatase with rutile increased. The activation energy of the rutile phase was found lower which indicated that uniform shape and morphology of TiO2nanoparticles. At same time, changes of activation energy value depended on the experimental conditions was observed.
Synthesis and Characterization of Gold Nanoplates onto Solid Substrates by Seed-Mediated Growth Method
Authors: Iwantono  , Umar Akrajas Ali , Taer Erman , Asyana Vepy
Published: May 2013

A simple technique of seed-mediated growth has successfully been performed to grow gold nanoplates onto solid substrates. The growth of gold nanoplates have been carried out attemperature of 28-30°C in the presence of a binary surfactant mixture: CTAB (cetyl trimethyl ammonium bromide) and PVP (poly-vinylpyrrolidone) with their various concentrations. Characterizations of the samples have been carried out by using UV-Vis spectroscopy, XRD and FESEM.UV-Vis spectra showed that the gold particles have grown with a various geometrical forms, such as spherical and others. XRD results informed that the presence of two peaks at 2θ: 38.195oand 44.393oindicated the gold nanoplates, with their crystal orientation of (111) and (200). FESEM images showed the edge-length size of nanoplates was dominated in the range of 11nm to 50 nm, with various morphologies of nanoplates, such as hexagonal,truncated hexagonal, triangular, square and spherical shapes.
Epoxidized Natural Rubber-Organomodified Montmorillonite Nanohybrids; Interaction and Thermal Decomposition
Authors: Salehabadi Ali , Mohamad Abu Bakar
Published: May 2013

Nanohybrids, based on a modified natural rubber,Epoxidized Natural Rubber (ENR-50), and organomodified montmorillonite (MMT) containing alkyl ammonium, were prepared by solvent casting technique. Morphology and non-isothermal degradation of ENR-50 and various ENR/MMT nanohybrids were characterized by POM, SEM and TG-DTG. In the hybrid materials,an increase MMT loading in the ENR-50 increased the maximum decomposition temperature (Tmax) of thermal profiles. Kissinger and Ozawa plots deduced a trend of the decomposition activation energy, Ed, which is related to the agglomeration and heat transfer ability of MMT. A mechanism comprising of the degradation of ENR-50 via scission of epoxy-isoprene chains to shorter chains, ring opening reaction and the possible interactions of modified nanoclay and ENR-50 is discussed.
The Effect of Zinc to Aluminium Molar Ratio on the Physico-Chemical Properties of Zinc-Aluminium-3,4-Dichlorophenoxy Acetate Nanocomposite
Authors: Ghazali Sheikh Ahmad Izaddin Sheikh Mohd , Hussein Mohd Zobir , Sarijo Siti Halimah
Published: May 2013

Layered double hydroxide (LDH) hybrid materials of Zn-Al-layered double hydroxide-3,4-dichlorophenoxy acetate acidnanocomposites (ZADs) were prepared by direct self-assembly method. The pH of the solution was adjusted to 7.5 using 2M NaOH. Various Zn2+ to Al3+ molar ratios, R ranging from 1 to 6 were used with a fixed concentration of 3,4-D at 0.3 M. The Powder X-ray diffraction (PXRD) patterns showed the formation of well-ordered nanocomposite with the expansion of basal spacing from 8.9 Å in the Zinc-Aluminium-Layered Double Hydroxide (ZAL) to 18.7 - 22.1 Å in the resulting nanocomposites. The Fourier transform infrared (FTIR)spectra for the nanocomposites showed features for both ZAL and ZAD, showing the successful intercalation of the organic moiety into the LDH interlayer. The percentage loading of 3,4-dichlorophenoxy acetati acid(3,4-D) in LDH was found to be increased from 34.7-48.1 % (w/w), as the mole fraction of Al decreased from 0.44-0.15. This study shows that the mole fraction of zinc ion was replaced by aluminium ion in the LDH plays an important role in controlling the physic-chemical properties of the resulting material.
A Comparative Study on the Effect of Adiabatic Extrusion by Twin-Screw Extruder to the Crystallization Pattern and Thermal Behavior of Polyamide 6/C20A Nanocomposites
Authors: Ismail Zulhelmi , Yusoh Kamal
Published: May 2013

The performance of an adiabatic extrusion in minimizing the risk of thermal degradation for PA6/C20A nanocomposites was investigated in this paper. The screw speed of twin-screw extruder was maintained at constant value of 100 RPM while the clay loadings C20A were varied between 1 wt %, 3wt % and 5 wt % respectively.Thermal gravimetric analysis was used to characterize the thermal property of polyamide6/C20A-nanocomposites and the crystallization pattern was thoroughly examined via the application of differential scanning calorimetry. The time taken for 10 wt.% mass losses of majority adiabatic extruded samples was observed to be longer as compared to the conventional extruded PA6/C20A samples. The combination effect of adiabatic extrusion and nanoclay presence in the PA6-matrix has managed to increase thermal resistant of PA6. The crystallinity grade for each of the samples with different loading of C20A. however has not diversed in value since the index of crystallinity (Xc) remains independent of C20-volume althoughconventional/adiabatic setting of extruder could possibly have greater effect on the crystalline feature of PA6/C20A nanocomposites.
Effect of Nanoindentation Loading Rate on Gold Ball Bond
Authors: Zulkifli Muhammd Nubli , Jalar Azman , Abdullah Shahrum
Published: May 2013

Nanoindentation tests with loading rates of 0.05 mN/s, 0.1 mN/s, 0.5 mN/s, and 1.0 mN/s were conducted on the Au ball bond. The effect of different loading on the Au ball bond were analysed based on qualitative and quantitative results. The displacement burst was more pronounced with the increment of loading rates. The increase of hardness value and the decrease of the reduced modulus value when the loading rate was increased are due to the effect of creep. It was found that the loading rate of 0.5 mN/s is the appropriate and stable value for the nanoindentation test on the Au ball bond.
Optimization of the Production of Aligned CNTs Array as the Gas Sensing Element
Authors: Mohamed Saheed Mohamed Shuaib , Norani Muti Mohamed , Burhanudin Zainal Arif
Published: May 2013

The synthesis of aligned multi-walled carbon nanotubes (MWCNTs) using thermal and floating catalytic chemical vapor deposition (CVD) method has been optimized in order to obtain MWCNTs with specific characteristics namely diameter and thickness of nanotubes array. Process parameters such as substrate preparation which involved buffer layer deposition, temperature and reaction duration were studied. Samples produced were analyzed using FESEM, HRTEM and Raman spectroscopy. Typical thickness of CNTs array obtained using thermal CVDis 38 µm whilst the ones from the floating technique have a wide range of thickness with the thickest being about 639 µm for the duration of 1 hour. Floating CVD method has the capability to produce good quality, aligned CNTs array with various thicknesses required to vary the electrode gap of the ionization-based gas sensor for the reduction of the breakdown voltage, leading to low power consumption and safe operation of the sensor.
Ex Situ Doping of ZnO Nanorods by Spray Pyrolysis Technique
Authors: Qurratu Aini Abd Aziz Siti Nor , Pung Swee Yong , Lockman Zainovia , Hamzah Nur Atiqah , Chan Yim Leng
Published: May 2013

An ultraviolet (UV) shielding agent based on Fe-doped zinc oxide nanorods (ZnONRs) was synthesized by ex-situdoping using spray pyrolysis technique. These Fe-doped ZnO NRs could reduce the inherent photocatalytic activity of zinc oxide while still maintaining their ultraviolet filtering capability. In this work, the effect of doping duration by spray pyrolysis technique on the optical property and photocatalytic efficiency of ZnO NRs was studied. The room temperature photoluminescence (PL) analysis on the Fe-doped ZnO NRs indicates the red-shift of violet emission peak, i.e. from 378.97 nm (undoped) to 381.86 nm (60 mins.doping). Besides, the reduction of IUV/Vis ratio of PL reveals that the ex-situ Fe doping deteriorated the crystal quality of ZnO NRs. The photocatalytic study shows that the rate constant of Fe-doped ZnO NRs was smaller than the undoped ZnO NRs. It means that the Fe-doped ZnO NRs were less effective in degrading the RhB solution.
Fabrication of Ca(OH)2 Nanostructures by Facile Solution – Based Synthesis at Various Reaction Temperatures as CO2 Adsorbent
Authors: Mohd Daud Farah Diana , Sreekantan Srimala , Mohamed Abdul Rahman
Published: May 2013

Calcium hydroxides (Ca(OH)2) nanostructures have been fabricated through simple facile solution based synthesis at different temperatures 35,45 and 55°C repectively.Ethanol was utilized as a medium for reaction. The synthesized powder was characterized by Field Emission Scanning Electron Microscope (FESEM SUPRA 35VP ZEISS), Fourier transform infrared (FTIR Perkin Elmer Spectrum One Spectrophotometer) and X-raydiffraction (XRD). Based on XRD analysis, the synthesis samples exhibited crystal hexagonal phase of Ca(OH)2.The crystallite size for powders prepared was between 17 nm to 31 nm. Short nanorod like structures was successfully obtained in 80 ml ethanol solution for entire temperatures. However, the length and diameter decreased with increased the reaction temperatures. Short nanorod synthesized at 55°C has small diameters and length compared at 35°C. Carbon dioxide (CO2) adsorption for synthesized powders was studied by simultaneous thermal analyzer (STA). Ca(OH)2 prepared at 35°C and45°C in 80 ml ethanol showed CO2 adsorption capacity about 9.3 mmol/g and 9.7 mmol/g respectively.
Effects of Reaction Temperature on CO2 Reforming of CH4 over Multi-Walled Carbon Nanotubes Catalyst with Co-Mo-MgO Nanoparticles
Authors: Khavarian Mehrnoush , Mohamed Abdul Rahman
Published: May 2013

The utilization of greenhousegases, such as carbon dioxide (CO2) and methane (CH4), is among the most important challenges in the energy research field. The catalytic activity behavior of CO2 reforming of CH4 (CRM) over synthesized multi-walled carbon nanotubes (MWCNTs) with Co-Mo and MgO nanoparticles was investigated. Based on conversion of reactants and production of syngas, the synthesized Co-Mo-MgO/MWCNTs were found to be a suitable catalyst for the CRM reaction. The CH4 and CO2 conversions were greatly inﬂuenced by the reaction temperature in the range of 750-1000 °C. The catalyst exhibited high activity and stability during 10 h reaction time with 82.68% conversion of CH4 at 950 °C respectively,without significant deactivation. The reaction rate of CH4 and CO2 over carbon nanotubes was affected signiﬁcantly by the reaction temperature.The syngas ratio was close to unity and no carbon deposition over the catalyst was observed after the termination of the reaction.
Stability of WO3/CuO Heterojunction Photoelectrodes in PEC System
Authors: Ng Kim Hang , Kadir Hasmida Abdul , Minggu Lorna Jeffry , Kassim Mohamad Bin
Published: May 2013

The tungsten trioxide (WO3) and copper(II) oxide (CuO) photoelectrodes have been fabricated from acidic aqueous solution of peroxy-tungstate and basic aqueous solution of copper sulphate-lactic acid respectively, by electrodeposition method. The samples produced were calcined at 450 °C for 30 minutes before the deposition of second layer. The CuO was layered on WO3 sample by electrodeposition of basic aqueous solution of copper sulphate-lactic acid, followed by annealing process at 450 °C for 30 minutes. On the other hand, the WO3 layer was casted onto CuO sample by sol-gel method and it was annealed at 450 °C for 30 minutes. The resulting samples were then characterized by XRD to confirm their structures. Photoelectrochemical characterization of the WO3, CuO and WO3-CuO bilayer photoelectrodes were carried out under 100 W xenon light illumination, in 0.5 M sodium sulphate solution with saturated calomel electrode (SCE) reference electrode and platinum counter electrode. The PEC stability of the electrodes was evaluated at -0.7 V vs SCE under irradiated condition.
Antibacterial Activity of Ag-TiO2 Nanoparticles with Various Silver Contents
Authors: Ahmad Barudin Nur Hidayati , Sreekantan Srimala , Thong Ong Ming , Sahgal Geethaa
Published: May 2013

Bacterial are highly transmitted in our environment and have been identified as a primary contributor to the problem of indoor air quality and consequently lead to the illness of the occupants. Recently, nanotechnology represents an innovative approach to develop new formulations based on metallic nanoparticles with antimicrobial properties. TiO2 has great promise to diminish bacterial activity. Antimicrobial activity of TiO2and Ag-TiO2 nanoparticles against Escherichia coli was examined in this study. TiO2 nanoparticles with various silver contents were synthesized by sol gel method to produce uniform size, unagglomerated state and homogeneous nanoparticles. The nanoparticles were characterized by X-Ray diffraction (XRD) and transmittance electron microscopy (TEM). The effects of different silver concentration were studied using cotton diffusion test under fluorescence light irradiation. 0.06 mol % Ag-TiO2 revealed best antibacterial activity. 0.06 mol % Ag-TiO2 have antibacterial inhibition zone of 38 mm at the concentration of 2.0 M against E. coli. Swab test bacterial counts on left palm, tile, mouse pad and cotton have been tested before and after spraying with 0.06 mol % Ag-TiO2. It showed that the bacterial count decreased for entire samples. The significant enhancement in the antibacterial properties of Ag-TiO2 nanoparticles under visiblelight irradiation is related to the effect of noble metal Ag by acting as electron traps in TiO2 band gap. The phase structure, crystallite size and crystallinity of TiO2 also play an important role inantibacterial activity. The killing mechanism of Ag-TiO2 undervisible light irradiation antibacterial activity over Ag-TiO2nanoparticles was proposed based on our observations.
Effect of CVD Synthesis Parameters on the Growth of Catalyst-Free ZnO NRs
Authors: Hamzah Nur Atiqah , Pung Swee Yong , Sreekantan Srimala , Qurratu Aini Abd Aziz Siti Nor
Published: May 2013

The main development of ZnO nanorods (NRs) is focused on the gold catalyst and heteroepitaxial approach.However, the presence of Au may generate undesired deep level traps in the ZnO bandgap, which could be very harmful to the performance of transistors. The objective of this study is to synthesize ZnO NRs via homoepitaxial growth without using foreign catalyst by Chemical Vapour Deposition (CVD) technique. The growth of catalyst-free ZnO NWs at different CVD synthesis parameters such as amount of Zn powder, substrate location and synthesis duration on the catalyst-free ZnO NRs were studied systematically. The effect of these parameters on the size and areal density of ZnO NRs provided a better understanding on the growth mechanism of NRs via the Vapour-Solid (VS) mechanism.
Absorption Characteristics of Ruthenium (Ru)-II Nanoparticles as a Dissolved Oxygen Sensing Material
Authors: Farahiyah A. , Menon P. Susthitha , Shaari S. , Saharudin S. , Abdullah M.S.
Published: May 2013

Ruthenium (Ru)-II complexes such as the Ruthenium-tris(4,7-diphenyl-1,10-phenanthroline)dichloride (Ru(dpp)32+)is commonly used for dissolved oxygen sensing because of their profound advantages such as visible absorption, a large Stokes’ shift, good fluorescence quantum yields, long excitation lifetimes and good oxygen quenching efficiency. In this study, we report on the absorption characteristics of (Ru(dpp)32+)when it is exposed to dissolved oxygen where the absorption was determined using ultraviolet-visible (UV-Vis) absorbance spectroscopy. The results show that by decreasing the concentration ofRu(ddp)32+, the absorbance remained constant at optical wavelength of 455nm while the intensity changes with the presence of dissolved oxygen. The sensitivity of detecting dissolved oxygen was proven to improve by increasing the amount of Ru(ddp)32+used.
Synthesis, Structural and Sensor Characterization of Ga-ZnO Nanodisk/Nanorods Prepared by One Step Polymer Assisted Hydrothermal Process on AlN/Si Substrate
Authors: Ramalingam R. Jothi , Dinesh G.
Published: May 2013

Synthesis and characterization of Ga-doped ZnO nanodisk and the formation of nanodisk/nanorod hybrid morphologies on AlN/Si substrate by polymer assisted one-pothydrothermal process have been studied. The morphology and structural properties were determined by field emission scanning electron microscopy (FESEM) and X-ray diffraction techniques. FESEM images clearly confirm the pure nanodisk formation for Ga-ZnO(0.5) at optimized ZnO concentration and hybrid nanodisk/nanorod formation obtained for Ga-ZnO (0.2) at lower ZnO concentration. The pure Ga-ZnO (0.5) nanodisk on AlN/Si thin film substrate showed effective response and fast recovery time towards UV light sensing in dark condition compared to low concentration route preparedGa-ZnO (0.2)/AlN/Si sample.
The Performance of Nanosilicate from Rice Husk Ash as Green Corrosion Inhibitor for Carbon Steel in 0.5M HCl
Authors: Asra Awizar Denni , Othman Norinsan Kamil , Daud Abdul Razak , Jalar Azman , Zulkafli Rabiahtul
Published: May 2013

Nanosilica powder produced from rice husk ash (RHA) via NaOH treatment has particle size in the range of 10-20 nm as revealed by transmission electron microscopy (TEM). The inhibitive action of nanosilicate from RHA on the corrosion of carbon steel SAE1045 in 0.5M HCl solution was studied using weight loss and potentio dynamic polarization methods. Result shows that the inhibition efficiency was increased with increasing of the inhibitor concentration. Nanosilicate was tremendously effective on carbon steel; exhibiting high inhibition efficiency attained 99%at optimum concentration of 175 ppm. Pitting was not observed on surface of carbon steel when the inhibitor was present. This finding was confirmed from surface morphology by scanning electron microscopy (SEM).
CuZnSnSe Thin Film Electrodes Prepared by Vacuum Evaporation: Enhancement of Surface Morphology and Photoelectrochemical Characteristics by Argon Gas
Authors: Sabli Nordin , Talib Zainal Abidin , Wan Mahmood Mat Yunus , Zainal Zulkarnain , Hilal Hikmat S. , Fujii Masatoshi
Published: May 2013

CuZnSnSe thin films were deposited by thermal vacuum evaporation with and without argon gas stream at room temperature. Effect of argon gas on surface morphology and on photoelectrochemical (PEC) characteristics of the films was studied. The electrodes prepared under argon gas showed better enhanced characteristics, due to slower nucleation and growth due to dilution effect of the inert gas. While both electrodes showed soundly good PEC behaviors in a hexacyanoferrate(III)/hexacyanoferrate(II) redox couple, the electrode with argon gas showed 20 fold enhancement in photoactivity, compared to the one without argon gas. The results manifested thin film electrode performance can be enhanced simply by inclusion of argon inert gas inside the preparation chamber, with no need for other procedures such as annealing.
Enhancement of Poly(9,9'-di-n-octylfluorenyl-2.7-diyl) Optoelectronic Properties in Novel Conjugated Polymer/Laser Dye Hybrid OLEDs
Authors: Al-Asbahi Bandar Ali , Haji Jumali Mohammad Hafizuddin , Yap Chi Chin , Salleh Muhamad Mat
Published: May 2013

The effect of laser dye (Fluorol 7GA) content on the optoelectronic properties of Poly ( 9,9'-di-n-octylfluorenyl-2.7-diyl) conjugated polymer (PFO) based OLEDs has been investigated. The PFO/Fluorol 7GA hybrids with weight ratios between 0.1 and 5 wt. % were prepared using the solution blending method. The blends were deposited on ITO (Indium Tin Oxide) substrate using spin-coating technique. Thin layer of aluminum was deposited on top of the films to act as electrode. Absorption and photoluminescence techniques were used to investigate the energy transfer in the blend. The device performance was investigated in terms of electroluminescence, luminance, luminance efficiency and color measurements. The Förster energy transfer occurred in the blends as evidence from optical spectroscopy and average distance between donor and acceptor molecules. The optimum ratio was 0.5 wt. % where highest enhancement in OLEDs performance was observed. These were attributed to the synchronize effect of efficient energy transfer from PFO to Fluorol 7GA and carrier trapping processes.
Synthesis of Titania Nanowires From Local Synthetic Rutiles
Authors: Masliana Muslimin , Meor Yusoff Meor Sulaiman , Wilfred S.P.
Published: May 2013

A new method for preparation of titania nanowires with diameter around 20 nmand length up more than 4um is described. The precursor was supply from local amang plant in Lahat, Perak which is produced the by product called synthetic rutiles. This precursor was mix with NaOH to form sodium titanate followed by heating at temperature of 550°C for 3 h. The sodium titanate formed by this way aggregated into 1D nanostructures and was subsequently transformed into titania nanowires during the heat treatment. The crystalline phase of the titania nanowires is rutile. The precursor as well as titania based samples were characterized by X-ray diffraction, Energy dispersive X-ray and scanning electron microscopy.
Preparation and Characterization of TiO2 Nanowire - Cu2O Nanocube Composite Thin Film
Authors: Naumar Fitri Yenni , Umar Akrajas Ali , Rahman Mohd Yusri Abd , Salleh Muhamad Mat , Umar Marjoni Imamora Ali , Nafisah Suratun , Saad Siti Khatijah Md , Tan Sin Tee
Published: May 2013

Composite of TiO2nanowire and Cu2O nanocube has been prepared. TiO2nanowire with ~240nm in thickness and 20 nm in length were synthesized by using liquid phase deposition(LPD) method at 50°C for 4h on ITO substrate. The anatase phase of TiO2nanowire was obtained by annealing the samples at 400°C for 1hin air. The Cu2O nanocubes were prepared by the reduction of Cu2+ions with ascorbic acid in the present of trisodium citrate and sodium dodecilsulfat (SDS) surfactant under an alkaline condition. The SDS addition was added with various concentrations namely 10 mM, 18 mM, and 26 mM during the Cu2O preparation for spin-coated onto TiO2nanowire at 3000 rpm for 30s. An optical property of TiO2Nanowire - Cu2O Nanocube has been characterized by UV-Vis spectroscopy.The original TiO2nanowire has single absorption peak at 318 nm, but it was shifted to 321 nm as Cu2O/SDS addition. A new peak at 440 nm was as the Cu2O nanocube absorption spectra. The Cu2O nanocube addition to the TiO2nanostructure film caused increase in the optical absorption of the system in the region 400 – 800 nm. We also studied the absorption properties of the hybrid system when Cu2O nanocube preparation under SDS condition. It was that found the increase in the SDS concentration has caused the optical absorption of the hybrid in this region decreased. This is believed due to the decrease of Cu2O nanocube size as the SDS concentration increase. This could be due to change in the TiO2nanowire-Cu2O nanocube hybrid-structure. This cooperate may find use in photoelectrochemical application.
Synthesis and Characterization of Nano-Wollastonite from Rice Husk Ash and Limestone
Authors: Ismail Hamisah , Shamsudin Roslinda , Hamid Muhammad Azmi Abdul , Jalar Azman
Published: May 2013

Wollastonite, CaSiO3 material was prepared from rice husk ash, as the source for SiO2 and limestone, source for CaO using sol-gel method. Rice husk ash and CaO powder was mixed together in 100ml distilled water with the rice husk ash/CaO ratios of 45:55 and 40:60. The mixed solution was place in the autoclave and heated at 135°C for 4 hours and calcined at 950°C for 1 and 2 hours. From the XRD results,ratio of 45:55 exhibited that b-wollastonite is the major phase and the minor phase is only contributed by cristoballite and by calcining the mixture for 2hrs would yield better crystallinity. Both of the rice husk ash:CaO ratios produced wollastonite materials in cylinder structures. Wollastonite with nano size grain was obtained for an hour calcination and 2 hrs of calcination would increase the grain size over 100 nm for ratio, 45:55 and 40:60.Therefore in order to get the nano size of wollastonite material, period of calcination process has to be controlled.
Synthesis and Characterization of Grape-Like SnO2 Structures Grown by a Thermal Evaporation Method
Authors: Lim Kar Keng , Hamid Muhammad Azmi Abd , Shamsudin Roslinda , Jalar Azman , Al-Hardan N.H.
Published: May 2013

Grape-like tin dioxide (SnO2) structures have been grown onp-type silicon (Si(100)) substrate synthesized by thermal evaporation of tin (Sn) without use of metal catalyst. The experiment were conducted in a three-zone tube furnace at a constant temperature of 1080°C,under 1.6% of oxygen (O2) gas in an atmospheric ambient with a controlled flow rate of 1.0L/min. The prepared SnO2film was characterized by using X-ray diffraction diffractometer (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy(EDX) and photoluminescence (PL) measurement. The grape-like SnO2structures were highly crystalline with particle size (resemble grape fruit) ranging from 120-550 nm and diameter of wire (resemble grape stem) around 120-160 nm.The PL spectrum of the grape-like SnO2structures exhibits a broad visible light emission with a peak centered at around 623 nm, corresponding to 1.99 eV and usual near band edge emission of SnO2is not observed.