bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of KI of Semi-Elliptical Surface Crack in Steel Structure Strengthened with FRP under Tensile Load
Authors: Zhao Chuan Yu , Huang Pei Yan , Zhou Hao , Zheng Xiao Hong
Published: October 2011

Defects like surface crack often appear in steel structures. To ensure the structural integrity and security, the new material such as fiber reinforced polymer (FRP) was adopted for strengthening and repairing. In this paper, three dimensional semi-elliptic surface crack in steel tension specimen strengthened with carbon fiber laminate (CFL) was studied, and numerical analysis was undertaken by Abaqus finite element software to study the stress intensity factor (SIF, KI) of the surface crack for CFL reinforcement effect. The results showed that, strengthening effect of CFL in front side was better than the back side of the steel plate; Crack shape ratio, a/c, had greater influence on strengthening effect in front side compared with little effect in the back side; The changes of crack relative depth, a/B, affected strengthening effect.
Numerical Study on Hydrodynamic Behavior of Deepwater Spar Platform with Different Mooring Configurations
Authors: Sun Jin Wei , Fan Xiu Tao , Wan Xiao Zheng , Liu Shi Xuan
Published: October 2011

The motion performance of Spar platform and dynamic characteristics for the mooring lines under different mooring configurations have been studied both in static analysis and coupled dynamic analysis. First, 3D hydrodynamic finite element model is built and the effects of the mooring system are taken into account by giving the specified pre-tension, angle and stiffness of the mooring lines on the fairleads. And hydrodynamic analysis of Spar platform is performed by the way of utilizing potential flow theory in frequency domain in order to calculate the hydrodynamic coefficients. Then, static analysis is applied to obtain restoring stiffness curves for the mooring system, structure displacements and mooring line tensions etc.. At last, coupled time domain analysis of the motion response of Spar is conducted for the coupled system and the dynamic tensions of mooring lines are calculated. The research results can be served as a reference for the selection and the performance study for mooring systems during preliminary design.
Effect of Oxygen Flow Rate on the Properties of Nanocolumnar ZnO Thin Films Prepared Using Radio Frequency Magnetron Sputtering System for Ultraviolet Sensor Applications
Authors: Mamat Mohamad Hafiz , Wan Syafinaz Wan Anwar , Musa Mohamed Zahidi , Khusaimi Zuraida , Malek Mohd Firdaus , Muhamad Salina , Sin Diyana Md , Rusop Mohamad
Published: October 2011

Nanostructured zinc oxide (ZnO) thin films were deposited on glass substrates using radio frequency (RF) magnetron sputtering system at different oxygen flow rates ranges between 0 to 40 sccm. Field emission scanning electron microscopy (FESEM) images was revealed that nanocolumnar ZnO structure thin films are produced on the substrates using high purity ZnO as the target at RF power of 250 W in the argon and oxygen gas mixture ambient. The XRD spectra reveal that the deposited films are preferentially grown along the c-axis indicating high ZnO crystallinity. The ultraviolet-visible (UV-Vis) spectra show that all samples are very transparent in the visible region (400 – 800 nm) with average transparency above 80 %. The photocurrent properties indicate that ZnO thin film prepared at oxygen flow rate of 20 sccm has the optimum characteristic for ultraviolet sensor applications. This finding suggested that the oxygen flow rates play important role and has critical value for semiconducting nanocolumnar ZnO growth in the sputtering system, which can produce ZnO thin film with high sensitivity of ultraviolet detection.
Optical Properties and Surface Morphology of PMMA: TiO2 Nanocomposite Thin Films
Authors: Lyly Nyl Ismail , Aziz Ahmad Fairoz , Habibah Zulkefle , Zaihidi Musa Mohamed , Abdullah Mohd Hanapiah , Herman Sukreen Hana , Noor Uzer Mohd , Rusop Mohamad
Published: October 2011

Sol-gel spin coated PMMA:TiO2 nanocomposite thin films on glass substrates were studied by comparing two types of the sol-gel solutions. Two types of PMMA:TiO2 nanocomposite sol-gel solutions were prepared; one using Degusa (P25), and the other one is using self-prepared TiO2 powder. The self-prepared nanosized TiO2 powder is obtained by drying the TiO2 sol-gel using solvothermal method followed by grinding the TiO2 crystal using ball miller. Triton-X was used as surfactant to stabilize the composite. Besides comparing the nanocomposite solution, we also studied the effect of the thin films thickness on the optical properties and their surface morphology. The optical properties and surface morphology were measured with UV-VIS spectrometer and atomic force microscopy (AFM). The result showed that nanocomposite PMMA with self-prepared TiO2 give high optical transparency than that of with Degusa (P25). The results also indicate that as the thickness is increased the optical transparency are decreased. Both AFM images showed that the agglomerations of TiO2 particles occurred on top of the thin film and the surface roughness increased when the thickness is increased. AFM results show that nanocomposited PMMA with P25 has high agglomeration particles compared to the other one.
Characterization of GaN p-n Junction Grown on Si (111) Substrate by Plasma-Assisted Molecular Beam Epitaxy
Authors: Radzali Rosfariza , Ahmad Mohd Anas , Zainuriah Hassan , Zainal Norzaini , Yam Fong Kwong , Woei Chin Che , Yusoff Mohd Zaki Mohd , Bakhori Siti Khadijah Mohd , Yusof Yushamdan
Published: October 2011

In this report, the growth of GaN p-n junction on Si (111) substrate by plasma-assisted molecular beam epitaxy (PAMBE) is demonstrated. Doping of the GaN p-n junction has been carried out using Si and Mg as n-type and p-type dopants, respectively. Silicon substrate is used to grow the GaNpn-junction. In order to improve the crystalline quality of the nitride based junction, AlN is used as a buffer layer. The optical properties of the sample have been characterized by photoluminescence (PL) and Raman spectroscopy.PL spectrum shows a strong band edge emission of GaN at ~364nm, indicating good quality of the sample.The presence of peak ~657cm-1 in Raman measurement has exhibited asuccessful doping of Mg in the sample. The structural properties are measured by high-resolution x-ray diffraction (HR-XRD) and scanning electron microscopy (SEM). The cross section of the SEM image of the sample has shown sharp interfaces.
XRD, FTIR and 13C CP/MAS NMR Studies of Composite Comprising Poly(vinyl acetate)-Silylated Si-MCM-41
Authors: Nurul Izza Taib , Endud Salasiah , Katun M. Nasir
Published: October 2011

A composite structure based on silylated MCM-41 and Poly (vinyl acetate) (PVAc) was synthesized via solution intercalation. Poly (vinyl acetate)-silylated Si-MCM-41 composite were characterized by XRD, FTIR spectroscopy and 13C CP/MAS NMR in order to determine the compatibility between PVAc and the silicate host. XRD study reveals that the framework of silylated Si-MCM-41 was not altered upon incorporation of PVAc. FTIR study showed that characteristic peak assigned to carbonyl group in PVAc was observed around 1741.6 cm-1 for all the composites indicating the presence of PVAc in the silylated Si-MCM-41. 13C CP/MAS NMR showed the increase of line width of the peak assigned to C=O carbonyl group indicating the increase in randomness of polymer chains in confined space. The shifting of the C=O carbonyl groups is a sign of the change in chemical environment of the carbonyl owing to the interaction of PVAc with the silica matrix of silylated Si-MCM-41.
The Investigation of Porous AlXGa1-XN Layers on Si (111) Substrate with GaN/AlN as Buffer Layer
Authors: Yusof Yushamdan , Yusoff Mohd Zaki Mohd , Ainorkhilah Mahmood , Zainuriah Hassan , Haslan Abu Hassan , Abdullah Mat Johar
Published: October 2011

High quality undoped AlxGa1-xN with high Ga composition was grown on Si (111) substrate, using GaN/AlN as the buffer layer, by plasma-assisted molecular beam epitaxy (PAMBE). The present work reports on the photoluminescence (PL) studies of porous AlxGa1-xN prepared by ultraviolet (UV) assisted electrochemical etching in a solution of 2 % concentration of KOH electrolyte under illumination of an UV lamp with 500 W power for 30 min. The optical properties of porous AlxGa1-xN sample was compared to the corresponding as-grown GaN. PL studies suggested that the porosity was capable of improving the lattice mismatch induced strain. Porosity induced PL intensity enhancement was found in nanoporous sample. The resulting nanoporous AlxGa1-xN display red-shifted PL spectra compared to the as-grown AlxGa1-xN. Appearance of the red-shifted emission is correlated with the development of highly anisotropic structures in the morphology.
Characterization of Nanostructured Nickel Aluminate Formation during Mechano-Chemical Recycling of Spent NiO/Al2O3 Catalyst
Authors: Mohammad Karim Nazemi , Sheibani Saeed , Rashchi Fereshteh , De La Cruz Victor Gonzalez , Martínez Alfonso Caballero
Published: October 2011

In this research, use of mechanical alloying method, as a new and effective route for the recycling of spent NiO/Al2O3 catalyst to nanostructured nickel aluminate spinel was investigated. Samples were characterized using different techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). It was found that the formation of NiAl2O4 was started between 15 to 20 hours of milling and completed after 60 hours. The final particles had relatively spherical shape with the size range of 5-50 nm.
The Effect of Nanoseed Concentration on the Aspect Ratio of Gold Nanorod
Authors: Nengsih Sri , Akrajas Ali Umar , Salleh Muhamad Mat
Published: October 2011

This paper reports the synthesis of gold nanorod with controlled aspect ratio prepared by varying the concentration of nanoseed addition into the growth solution via seed mediated growth method. In typical process, the gold nanorod with aspect ratio from ca. 1.7 to 3.1 can be successfully obtained. The nanorod seems to be perfect rod morphology instead of bone-like or tear drop structure. Owing to the simplicity in preparing the gold nanorod, the present approach could be used as potential alternative for producing gold nanorod with special properties for used in the currently existing application.
Characterization of Urea versus HMTA in the Preparation of Zinc Oxide Nanostructures by Solution-Immersion Method Grown on Gold-Seeded Silicon Substrate
Authors: Azlinda Azlinda Ab , Khusaimi Zuraida , Abdullah Saifollah , Rusop Mohamad
Published: October 2011

Zinc oxide (ZnO) nanostructures prepared by immersion method were successfully grown on gold-seeded silicon substrate using Zinc nitrate hexahydrate (Zn (NO3)2.6H2O) as a precursor, separately stabilized with non-toxic urea (CH4N2O) and hexamethylene tetraamine (HMTA). The effect of changing the stabilizer of ZnO solution on the crystal structure, morphology and photoluminescence properties of the resultant ZnO is investigated. X-ray diffraction of the synthesized ZnO shows hexagonal zincite structure. The morphology of the ZnO was characterized using Field Emission Scanning Electron Microscope (FESEM). The growth of ZnO using urea as stabilizer shows clusters of ZnO nanoflower with serrated broad petals were interestingly formed. ZnO in HMTA showed growth of nanorods. The structures has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors. The formation of ZnO nanostructures is found to be significantly affected by the stabilizer.
Study Phase Separation of Donor: Acceptor in Inkjet Printed Thin Films of Bulk Heterojunction Organic Solar Cells Using AFM Phase Imaging
Authors: Fauzia Vivi , Umar Akrajas Ali , Salleh Muhamad Mat , Yahaya Muhammad
Published: October 2011

This paper reports an application of Atomic Force Microscopy (AFM) phase imaging to observe the phase separation between electron donor and acceptor materials in bulk heterojunction organic solar cells. The solar cells were fabricated using inkjet printed thin films of blended poly (3-octylthiophene-2,5-diyl)(P3OT) and (6,6)-phenyl C71 butyric acid methyl ester (PC71BM) as donor and acceptor materials respectively. The content PC71BM in the blended was varying from 25, 50 and 75 wt %. The AFM phase images of the thin film which contains 25 wt % PC71BM indicated that the acceptor molecules, PC71BM, are well distributed in the polymer chain of donor material, P3OT. The solar cell contains this film has the highest generated photocurrent. Hence, the phase separation between electron donor and acceptor materials in bulk heterojunction organic solar cells is one essential aspect that influences generation of photocurrent.
Effect of Calcination and Reduction Process on MWCNT Growth during Synthesizing MWCNT-Alumina Hybrid as Composite Reinforcement
Authors: Kudus Muhammad Helmi Abdul , Hazizan Md Akil , Mohamad Hasmaliza
Published: October 2011

Multiwall carbon nanotube (MWCNT) and alumina hybrid compound prepared via chemical vapour deposition (CVD). The CVD process always reported that the catalyst must undergo calcinations and reduction process before growing the carbon nanotube (CNT). In this work, MWCNT-alumina hybrid was successfully synthesized via simple CVD method. The morphologies study showed that the MWCNT-alumina hybrid with calcination and reduction, and calcination without reduction has been successfully synthesized.
Benzoyl Peroxide Initiated Grafting of 3-Aminopropyltriethoxysilane to Multiwalled Carbon Nanotubes
Authors: Junidah Abdul Shukor , Azizan Aziz , Jaafar Mariatti
Published: October 2011

A new method to functionalize multiwalled carbon nanotubes (MWCNT) with 3-aminopropyltriethoxysilane (APTES) has been established using benzoyl peroxide (BPO) as initiator. The functionalization was carried out through free radical reaction by thermal decomposition of benzoyl peroxide at 110°C. The reaction liberated carbon dioxide and generated phenyl free radicals. The phenyl free radicals initiated in-situ functionalization represent a simple means of creating reactive site on the surface of MWNT as well as on APTES. The functionalized MWNT was characterized using X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM results showed that the APTES has been successfully grafted onto MWNT. Due to the high radical reactive trap of MWNT, APTES radical are easily grafted onto MWNT surface to form covalent bond. XPS results clearly indicate alkoxylsilane and amide groups of APTES were grafted on the MWNT surface with the formation of C-O-Si and C-N bonds as evidence. From the XRD results, it was found that the surface functionalized does not give any effect on the MWNT graphitic structure.
Nanotubular Transition Metal Oxide for Hydrogen Production
Authors: Sreekantan Srimala , San E Pei , Lai Chin Wei , Kregvirat Warapong
Published: October 2011

TiO2, transition metal oxide nanotubes were successfully grown by anodizing of titanium foil (Ti) in ethylene glycol electrolyte containing 5wt % hydrogen peroxide and 5wt % ammonium fluoride for 60 minutes at 60V. It was found such electrochemical condition resulted in the formation of nanotube with average diameter of 90nm and length of 6.6 µm. These samples were used to study the effect of W loading by RF sputtering on TiO2 nanotubes. Amorphous TiO2 nanotube substrate leads to enhance incorporation of W instead of anatase. Therefore for the entire study, W was sputtered on amorphous TiO2 nanotube substrate. TiO2 nanotube sputtered below 1 minute resulted in the formation of W-O-Ti while beyond this point; it accumulates to form a self-independent structure of WO3 on the surface of the nanotubes. TiO2 nanotube sputtered for 1minute at 100W and annealed at 450°C exhibited best photocurrent density (1.4 mA/cm2) with photoconversion efficiency of 2.5%. The reason for such behavior is attributed to W6+ ions allows for electron traps that suppress electron-hole recombination and exploit the lower band gap of material to produce a water splitting process by increasing the charge separation and extending the energy range of photoexcitation for the system.
Study of Nano Ni/CeO2-SiO2 Catalysts for Biogas Dry Reforming
Authors: Sudarno Sudarno , Taufiq-Yap Y.H.
Published: October 2011

CeO2-SiO2 (C-S) Binary Oxides Were Prepared by Deposition Precipitation as Modified Support. Nanoparticle Nickel Catalysts (5 Wt.%), Supported on SiO2 and CeO2-SiO2 Were Prepared by Impregnation. Catalysts Were Identified by Several Characterizations (XRD, BET, TPR, TPD and TEM). the Analyses Showed that Nanoparticle Ni Supported on CeO2-SiO2 Catalysts Gave Better Properties in Reducibility, Basicity, Ni Metal Dispersion and Size Compared to the Nickel Catalysts Supported on the Single Oxide SiO2. the Catalytic Test of Dry Reforming of CH4 with CO2 (DRMC) Reaction Was Conducted Using Temperature Programmed Reaction (TPRn) Technique which Connected to an Online Mass Spectrometer. the Catalytic Test Showed that Ceria (CeO2) Loading Influenced the Activity, Mainly the Hydrogen Production. Ni Catalyst with 9 Wt.% of Ceria Exhibited the Highest Hydrogen Production and it Was Suggested to Be the Optimum Value of Ceria Loading. in Addition, the Lower Amount of Carbon Was Observed on the Ni/9C-S Catalyst. this Revealed that the Addition of an Appropriate Amount of Ceria Increased the Hydrogen Production and Reduced the Carbon Formation.
Preparation and Characterization of Poly(lactic acid)/Difatty Acyl Urea/Modified Clay Nanocomposite
Authors: Al-Mulla Emad A. Jaffar
Published: October 2011

In this study, difatty acyl urea (DFAU), synthesized from palm oil, and natural clay (sodium montmorillonite) were used to prepare organoclay (OMMT). The clay modification was carried out by stirring the clay particles in an aqueous solution of DFAU at which the clay layer thickness increased from 1.25 to 2.82. This OMMT was then used for nanocomposite production to improve the property balance of poly (lactic acid) (PLA) by solution casting process. The nanocomposite was characterized using various apparatuses. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) results confirmed the production of nanocomposite. PLA modified clay nanocomposite shows higher thermal stability and significant improvement of mechanical properties in comparison with pure PLA. The use of DFAU as a modifier will reduce the dependence on petroleum-based surfactant. In addition to its applications such as films and textile fibers, this nanocomposite represents a good candidate to produce disposable packaging because they have good mechanical, thermal properties, fabricability and processability.
Solvent Effects on the Electrical and Optical Properties of Nanocomposited MEH-PPV:TiO2 Films for Organic Solar Cells Application
Authors: Zahid Fazlinashatul Suhaidah Binti , Saad Puteri Sarah Binti Muhamad , Rusop Mohamad
Published: October 2011

The influence of organic solvent on the electrical and optical behavior of poly [2-methoxy-5-(2-ethylhexyloxy-p-phenylene-vinylene)] (MEH-PPV): Titanium Dioxide (TiO2) active layer has been investigated. The performance of the nanocomposite thin films varied depending on different type of solvent (chloroform, tetrahydrofuran (THF), toluene, xylene and 1,3-Dicholorobenzene) to dissolve MEH-PPPV at concentration of 20 mg/20ml. The solvent used to dissolve MEH-PPV has a dramatic effect on the polymer properties and characteristics due to different chain interaction, crystalline structure formation and surface morphology. The electrical properties of nanocomposited MEH-PPV: TiO2 thin films were measured by solar simulator in dark and under AM 1.5, 100 mW/cm2 white light illumination condition while the characterization of optical properties has been done using UV-VIS spectrophotometer to evaluate the absorbance as well as the transmittance. By comparing the nanocomposite thin films with the same weight MEH-PPV: TiO2, it was found the thin film which used 1,3-Dicholorobenze as a solvent has the highest conductivity around 338.64x103 S.m-1. However for the optical properties, solvent of xylene gives the highest absorption coefficient at 8.4x106 m-1. The dispersion of nanocomposited MEH-PPV:TiO2 and film formation reproducibility, these solvents showed that its affected film resistance and dispersion stability in the thin films.
Preliminary Study on Inducing Incompact Callus of Polygonum cuspidatum Using the Medium with Perlite
Authors: Li Xing Lin , Wang Dan Dan , Gao Jie , Cui Xing Hua , Zhao Jun , Zhang Li Ming , Gao Wen Yuan , Xiao Lan
Published: October 2011

.Preparation of the suspension cells ofPolygonum cuspidatumneeded the incompact calli by inducing the explants, but the calli fromPolygonum cuspidatumreported, always were too tight to fit for obtaining a lot of the single cells or small cell aggregations. In this paper, we used its stem apex as the explant to inducing the calli in the medium containing agar or perlite, respectively, and analyzed the calli development ratio, the calli texture property and the calli differentiation. The results indicated that, compared with the agar, the calli induced developed more rapidly in the medium using the perlite; the suspension cells were more easily gotten from the calli, and their cell aggregations were well dispersed and little grown into the differentiated tissues. As a consequence, the perlite, instead of the agar, may be used as a solid component of the medium to induce incompact callus ofPolygonum cuspidatum.
Finite Element Simulation and Respond Surface Optimization on Stretch Bending of Square Tube Aluminum Profile
Authors: Liang Ke Feng , Chen Ze Zhong , Wang Shui Miao , Zheng Jie
Published: October 2011

With the adoption of ABAQUS/Explicit as the simulation platform, a 3D finite element model has been established to simulate the stretch bending of square tube aluminum profile which is used as the door frame of fork lifter. Four characteristic points are put forward to evaluate the distortion of cross section during deformation, and the influence to distortion of cross section from some key parameters, such as bending radius and thickness of profile, is analyzed. An orthogonal experiment is designed to evaluate the influence to deformation from other forming parameters, including preload, fill rally and filling pressure which occurred in the stretch bending process. Then neural network based response surface method and genetic algorithm are used to optimize the parameters mentioned above. Finite element simulation proved that the optimized result is valuable to reduce the distortion of cross section of profile and improve formability.
The Enhancement of Heavy Crude Oil Recovery Using Bacteria Degrading Polycyclic Aromatic Hydrocarbons
Authors: She Yue Hui , Shu Fu Chang , Zhang Fan , Wang Zheng Liang , Kong Shu Qiong , Yu Long Jiang
Published: October 2011

Two strains of bacteria degrading polycyclic aromatic hydrocarbons (PAHs) were isolated using enrichment cultures of various heavy crude oil samples obtained from the Dagang Oilfield. The strains, namely S17 and S28, are able to degrade crude oil using phenanthrene as the sole carbon and energy source. The crude oil composition analysis indicates both strains are able to degrade heavy hydrocarbon components in crude oil. Then, the viscosities of heavy crude oil with S17 and S28 were decreased, and the surface tension between fermentative fluid and air were also decreased. The core flooding tests demonstrated that the fermentation broth, containing the two strains, can improve the residual oil recovery ratio by approximately 12.26% after polymer flooding.
Issues in Welding of HSLA Steels
Authors: Jindal Sandeep , Chhibber Rahul , Mehta N.P.
Published: October 2011

The application of High Strength Low Alloy (HSLA) steels has expanded to almost all fields viz. automobile industry, ship building, line pipe, pressure vessels, building construction, bridges, storage tanks. HSLA steels were developed primarily for the automotive industry to replace low-carbon steels in order to improve the strength-to-weight ratio and meet the need for higher-strength materials. Due to higher-strength and added excellent toughness and formability, demand for HSLA steel is increasing globally. With the increase of demand; other issues like the selection of filler grade and selection of suitable welding process for the joining of these steels have become very significant. This paper discusses the various issues regarding selection of suitable grade and selection of suitable welding process for joining of HSLA steels and issues concerning the structural integrity of HSLA steel welds.
A Study of Modification of Fly Ash and its Adsorption Effect on Cu2+ of Wastewater
Authors: Song Juan Juan , Tu Li
Published: October 2011

The comprehensive utilization of fly ash mainly concentrated is in construction engineering channels, road engineering, it used to deal with waste water is full of hope. As this, it can achieve the purpose of using the waste to conduct waste. Fly ash was modified by a microwave radiation. This method was simple and easy to operate . When the dosage of Modified fly ash is 4g, the pH value is 6.2, the mixing time is 50min, the initial concentration of copper solution is 1.85mg/L ,Adsorption rate of modified fly ash on Cu2+ reached 96%.
Prediction of Breaking Elongation of Polyester/Cotton Yarn in Ring Spun Processing
Authors: Zhao Bo
Published: October 2011

The artificial neural network model is used to predict the breaking elongation of polyester/cotton ring spinning yarn in this paper. In order to achieve the objective, a series of trials is conducted. The prediction values and actual test values of which are found to be rather close. Therefore, the artificial neural network model proves to be more feasible in the prediction of breaking elongation of polyester/cotton ring spinning yarn.
A NoSQL Framework Based on the DHT
Authors: Peng Zheng Hong , Luo Xiao Ming
Published: October 2011

In light of the current development of NoSQL(Non-relational database) and DHT [1] (Distributed Hash Table )is features, this article first proposes the adoption of B + tree as a DHT data structure, which can reduce the path length when the users find the corresponding node address, make the search length maintain the tree height and support the search of the data range. This article secondly advices to use the control node to manage and monitor DHT data distribution of NoSQL, reducing the burden of DHT routing and improving the efficiency of data search. Experimental results show that such a framework can greatly improve the routing efficiency and speed up the user access speed.
Experimental Study on Flexural Bearing Capacity of Reinforced Ceramsite Concrete Beam
Authors: Yang Wei Jun , Pi Zheng Bo , Mo Zhen Lin
Published: October 2011

In order to investigate the flexural bearing capacity of reinforced ceramic concrete beams, static loading experiments were carried out. 10 ceramic reinforced concrete beams and 2 non-reinforced ceramic concrete with different steel ratios, cover thicknesses and bar diameters were fabricated. The gauges of concrete was arraged on the surfaces of section in mid-span and and steel gauges was arraged on the surfaces of steel bars. The loading device was consisted of a 200kN hydraulic jack, a distributive girder and reaction frame while the dial indicators was arraged in supports and mid-span. The strain of concrete and steel bar in different loading along with the crack,yield and utimate of load were recorded .It found that the stress-strain law, crack extension regularity , failure modes of specimens was similar to the ordinary concrete beams and the current procedures formulas about flexural bearing capacity is reliability. It also found that both ceramic aggregate and cement mortar were crushed for the perfectly bonding of the interface and the strength of aggregate was to be fully utilized.
Design and Development of Intelligent Release Control Unit Based on LPC2478
Authors: Zhao Li Xin , Su Wei , Wu Liang Sheng
Published: October 2011

Intelligent release is core control unit of intelligent appliances, which is used to protect power system and power devices from damage under the faults. In this paper, with LPC2478 as Microcontroller, an intelligent release control unit with Ethernet communication functionality was presented. The intelligent release control unit’s basic functions and extended functions were described in brief. Implementation method of control unit was illustrated in detail. Process flow chart for fault diagnosis was supplied. Full-wave Fourier algorithm was adopted to compute fundamental components and harmonic components to filter decaying DC component and non-integer harmonic. This release can be adjusted according to the requirement of power quality to avoid malfunction under the circumstance that non-fault current and voltage fluctuation occur. Furthermore, through Ethernet communication, more functionality can be implemented to make the release more intelligent.
Multiattribute Reservoir Prediction of Hei 49 Block in Daqingzi Oilfield, NE China
Authors: Yuan Yong , Zhang Jin Liang , Song Ai Xue
Published: October 2011

Reservoir plane features of Hei 49 block in Daqingzi Oilfield is analyzed with multiattribute analysis. Through the production of fine synthetic seismograms, the block is analyzed by non-linear multiattribute. The authors set up the relationship between the log information and and the multi-attribute, and this relationship will calculate the seismic properties of theogram demarcation and extrapolate well curve. The way is used to establish statistical relationships by nonlinear artificial neural network. Therefore, seismic attribute volume can be transformed into a variety of reservoir parameter data volume. The method to establish relations between seismic attributes and reservoir parameters overcome the problem of inversion's multiple solutions caused by the geological model and seismic wavelet, and it is a more realistic prediction for this block's reservoir prediction and description.
Landing Motion Simulation of Autonomous Underwater Lurk Vehicle
Authors: Zhang Peng , Song Bao Wei , Du Xiao Xu
Published: October 2011

Autonomous underwater lurk vehicle is a new type of autonomous underwater vehicle, and the advantages of autonomous underwater lurk vehicle are intelligent, long-term working, covert, high-performance and recyclables, etc. It leads great contribution to the civilian and military application. In this paper, the frames were built first. Then, based on rigid body momentum and moment of momentum theorem, the dynamics equation of autonomous underwater lurk vehicle was built. At last, the landing motion of the autonomous underwater lurk vehicle was simulated. The simulation results show preliminarily that the autonomous underwater lurk vehicle can steady complete the required landing motion.
CAE Analysis and Improvement Design of Double-Decker Coach in Full Front Impact
Authors: Li Qiang , Shen Fu Lin , Zhang Guo Sheng , Zhou Wei , Zhao Kan
Published: October 2011

According to ECE R94 and GB 11551-2003, the full front impact simulation against rigid barrier of double-decker coach at the speed of 50km/h is carried out using LS-DYNA, so as to study the deformation characteristics and crash safety in front impact accidents. Based on the comparison of deformation, energy-absorbed, and injure indicators of test dummies before and after structure improved, we offered improvement program by strengthen its front wall and adding compression buffer device, which can effectively reduce occupant injury in a frontal collision, and provides basis technology for the passive safety improvement of double-decker coach.
Intelligent Controller Design for Air Conditioning with Multiple Power Saving
Authors: Xiang Xin Jian
Published: October 2011

An intelligent controller for air conditioning with multiple power-saving is described in this paper. Multiple power-saving feature means: (1) Optimizing the air conditioning compressor curve according to the variation rule of the temperature difference between indoor and outdoor in one day,. (2) Using temperature detection module to control the indoor target temperature no less than pre-set limit and prevent the compressor from starting when outdoor temperature is below the lower limit, (3) Keeping outdoor fan running for a while to make full use of the remaining cooling air stored in the air conditioning when the compressor stops, (4) Cutting the power off when the compressor is standby by using standby monitoring module. The controller hardware is based on ARM microprocessor; connecting with remote control decoding, real-time clock, temperature detection, standby monitoring, and compressor control module. Softwares are made up of main program, remote control decoding program, temperature detection program and compressor control program. After testing, the controller can save more than 20% power and still has a good cooling effect.
A PDA-Based Solution for the Realization of Green Leafy Vegetable Water-Fertilizer System
Authors: Ke Shun Kui , Li Lei , Miao Yu Bin , Huang Dan Feng
Published: October 2011

Water-fertilizer management is one of the most important parts in the realization of green leafy vegetables precise cultivation. This paper mainly focus on the problem of manual records are time-consuming and difficult to maintain, introduced to apply Personal Digital Assistant (PDA) into the whole process of green leafy vegetables water-fertilizer management. By the methods of real-time gaining of the site environment data, dynamical identifying the greenhouse ID and long-distance data transmission between PDA and database server water-fertilizer management in the green leafy vegetables production can be realized. The results show that the efficiency of green leafy vegetable water-fertilizer management can be improved by PDA-based solution.
Characterization and PL Properties of Ge-Induced Crystallization of a-Si Films Deposited by Magnetron Sputtering
Authors: Kang Kun Yong , Deng Shu Kang , Hao Rui Ting , Li De Cong
Published: October 2011

In this paper, we present the characterization of Ge-induced crystallization of amorphous Si (a-Si) films deposited by magnetron sputtering. The film structures of a-Si films were characterized by Raman spectroscopy, Atomic Force microscope (AFM), and field emission scanning electron microscope (FESEM). The result show that 60% of a-si film with a layer of 400 nm Ge buried is crystallized at growth temperature of 800 °C. The surface roughness and average surface grain size obtained by AFM is 2.39 nm and 60 nm for the crystallized film, respectively. The films growth at temperature of 500°C and 650 °C shows a PL spectrum band from 1.6 eV to 1.8 eV, and the PL peak shifts to lower energy as the growth temperature increased. As for the film grown at 800 °C, the PL spectrum is nearly extinguished. The crystallization of a-Si film induced by buried Ge might be a useful technology to develop high quality poly-Si film without annealing.
Artificial Neural Network Approach for Solving Power Flow Problem: A Case Study of Ayede 132 KV Power System, Nigeria
Authors: Osofisan P.B. , Ilevbare J.O.
Published: October 2011

The main objective of this research work was to use Artificial Neural Network (ANN) based method for solving Power Flow Problem for a power system in Nigeria. This was achieved using the Backpropagation (multilayered feed-forward) Neural Network model. Two Backpropagation neural networks were designed and trained; one for computing voltage magnitudes on all buses and the other for computing voltage phase angles on all PV and PQ buses for different load and generation conditions for a 7-bus 132 kV power system in South-West Nigeria (Ayede). Due to unavailability of historical field records, data representing different scenarios of loading and/or generation conditions had to be generated using Newton-Raphson non-linear iterative method. A total of 250 scenarios were generated out of which 50% were used to train the ANNs, 25% were used for validation and the remaining 25% were used as test data for the ANNs. The test data results showed very high accuracy for the ANN used for computing voltage magnitudes for all test data with a Mean Square Error (MSE) of less than 10-6. Also, the ANN used for computing voltage phase angles showed very high accuracy in about 80% of the test data and acceptable results in about 97% of the test data. The MSE for all the test data results for the ANN computing voltage phase angles was less than 10-2.
Outage Analysis and System Integrity of an 11kV Distribution System
Authors: Adegboye B.A. , Dawal E.
Published: October 2011

The paper studied the various faults occurrence on the 11kV the Coca Cola feeder (in Kaduna South of Nigeria) and the outages encountered due to such faults. The equipment installed on the feeder and their specifications were identified. The monthly maximum load analysis of the injection substation was conducted. The paper proposes measures of minimizing faults and recommends the ring main system of distribution as a means of improving the system integrity of the distribution system.
On the Generation of Random Numbers for Symmetric Cryptography Utilizing Astronomical Data
Authors: Rubesh Anand P.M. , Bhaskar Vidhyacharan , Bajpai Gaurav , Asemota Godwin Norense Osarumwense
Published: October 2011

In this paper, a novel method for obtaining the random numbers utilizing astronomical data is proposed. The method uses two different algorithms for generation of random numbers sequence. Astronomical data collected from the scientific study of the universe, especially of the relative motions, relative positions of astronomical objects are utilized in our algorithms. The first algorithm uses a particular astronomical object in a fixed position for the random number generation. The random sequence is obtained from the relative positions of other astronomical objects with reference to the selected object. The second algorithm selects any diverse astronomical object as a reference in a varying mode for computation of the relative positions of different objects with that reference to generate the random number stream. Both algorithms use mathematical equations for computing the next jump or hop to the other astronomical object. The generated random numbers obtained from the two algorithms are tested with a standard statistical test suite including, frequency test, run test, random binary matrix rank test, complexity test, universal test and entropy test. The results obtained from the statistical tests of the two algorithms are compared with the other publicly available random number generation techniques, like, linear congruential and modular exponentiation. The preliminary results show that the algorithms perform well. The random numbers generated by our method has sufficient period and unpredictability that makes them suitable for consideration as encryption keys in symmetric cryptography.
Performance Optimisation of Mobile Ad hoc Reactive Routing Protocols
Authors: Lawal Bello , Bakalis Panos , Manam Samuel John , Eneh Titus
Published: October 2011

In this paper, we optimized the performance of Ad hoc on Demand Vector (AODV) and Dynamic Source Routing (DSR) protocols through simulation. Numerical and simulation results presented illustrate how the performance of an ad hoc network protocol drastically changes as a result of changing the mobility model and ambient noise level in the network. The simulation results showed that, in the presence of ambient noise level in the network, AODV and DSR protocols have a significant improvement in end-to-end delay reduction with 68.5 % for AODV and 86.8% for DSR respectively. The network load simulation result revealed that DSR protocol maintains a constant routing load while the AODV protocol shows a 75% drop in routing load.
Formation of Segmented Chips in Semi-Finish Turning of α-Titanium Alloy BT5
Authors: Awopetu Olayinka O. , Dahunsi Olurotimi A. , Aderoba Adeyemi A. , Johnson Temidayo Oluwagbenga
Published: October 2011

Machining is gradually giving way to alternative manufacturing methods for titanium components. Although powder metallurgy based methods are more complicated and expensive, they are gaining more ground because of the difficulty of machining titanium due to its low thermal conductivity. Moreover documented information on research works on titanium remains so limited in comparison with steel and aluminium. This paper highlights the importance of titanium based alloys, its properties and areas of application as well as its major classifications. A typical case of semi-finish turning of α-titanium BT5 alloy is also presented. Results of chip root examination based on the application of a quick-stop mechanism with about 11m/s withdrawal speed to freeze the cutting operation is also presented, thereby highlighting some main features that are peculiar to the chip formation in titanium as compared with other materials.
Reengineering a Workplace to Improve Layout: A Study of a South African Design Studio
Authors: Nemarumane M. , Mbohwa C.
Published: October 2011

This paper focuses on the redesign of the No-Limits Design Studio’s layout with a view to improve its organisational efficiency and effectiveness. It was found that the studio’s existing layout resulted in employee stress, low employee motivation, low customer satisfaction, and also to employees not performing at their full potential. Data were collected using interviews, to reveal the problems that existed within the studio from both the customers’ and employees’ viewpoints. Non-participatory observations were also conducted and these focused mainly on the studio’s daily operations and activities over a period of one year through action research methods involving on-the-job experiential learning. The study demonstrated that, for an organizational layout to be effective, the organization has to plan the desired layout, implement the layout according to the plan and integrate it to form part of the organization’s culture. It was found out that the studio should redesign its layout, focus on the motivation of employees and improve conflict management strategies in order to improve its organizational capabilities.
Corrosion Inhibition of Multi-Component Aluminium Alloy in Hydrochloric Acid Solution by Aqueuos Extracts of Bitter Leaf (Verninia amygdalina) Powder
Authors: Abdulwahab M. , Kasim A. , Kamilu Bello Bello , Gaminana J.O.
Published: October 2011

The corrosion inhibition of an aqueous extract of bitter leaf on aluminium alloy in 0.5M hydrochloric acid solution at various temperatures and concentrations has been studied using weight loss measurement method. The influences of concentration, temperature and immersion period on the inhibition efficiency of the inhibitor system were investigated. It was found that the corrosion rate was significantly reduced in the presence of the natural inhibitor at all concentrations considered. The result also revealed the good inhibiting action of bitter leaf extract at optimum experimental conditions; acting as anodic type. The inhibitive action was satisfactorily explained by both thermodynamic and kinetic models.
Theoretical Dimensionless Breakthrough Time of a Horizontal Well in a Vertically-Stacked Two-Layered Reservoir System with Varying Architecture Part II: Letter ‘B’ Architecture, Bottom Water Drive Mechanism
Authors: Adewole E. Steve
Published: October 2011

When a reservoir experiences water influx, the actual source of the water often cannot be ascertained with precision. Thus well work over measures to minimize the water may not be easy to fashion. Bottom water encroaches through the bottom of the reservoir and rises vertically, appearing in all the wells in the field at the same time, if the wells experience the same production histories. This further makes work over difficult, more so, if there are other external fluid influences akin to a top gas. However, if the arrival time is known, then factors affecting bottom water movement, with or without any other contiguous top gas, may be studied with a view to fashioning an effective work over to mitigate premature water arrival into the well. Horizontal wells are already known to delay encroaching water breakthrough time. For a cross flow layered reservoir completed with a horizontal well in each layer, flow dynamics will certainly be different from a single layer reservoir due to differences in individual layer, layers fluid, wellbore and interface properties and rate histories. In this paper, theoretical expressions for predicting dimensionless breakthrough times of horizontal wells in a two layered reservoir of architecture like letter ‘B’, experiencing bottom water drive mechanism of different patterns, with or without a top gas, are derived. The theoretical breakthrough times are based on dimensionless pressure and dimensionless pressure derivative distributions of each identified model. Twenty-seven (28) different models emerged as the total of the different models possible.
Calculating Hydrodynamic Loads on Pipelines and Risers: Practical Alternative to Morison’s Equation
Authors: Iyalla Ibiye , Hossain Mamdud , Andrawus Jesse
Published: October 2011

Hydrodynamic stability analysis is one of the major tasks in the design of subsea pipelines and risers. The analysis is important to ensure stability of pipelines and risers under the action of the hydrodynamic forces produced by waves and currents during construction and operation stages. Morison related these hydrodynamic forces to kinematic wave properties, water particle velocity, and acceleration. However, previous studies show that Morison’s equation does not describe accurately the forces for combined wave and steady current flow. The actual measured forces differ significantly from the forces calculated using Morison’s equation. Though Morison’s equation leads to easy computer application for design purposes, it is a very conservative approach resulting in high cost of construction of offshore structures. In this paper the Wake II Model is incorporated into MathCAD software to practically determine hydrodynamic forces acting on cylindrical offshore structures. The Wake II Model takes into account the vortex shedding effect in the wake of a bluff body resulting in velocity reversal, thus the velocity is modified to include this effect. The modified velocity, time dependent drag and lift coefficients are then used to calculate hydrodynamic forces of lift and drag using MathCAD software. The results showed that the forces predicted using the Wake II Model is significantly less in comparison to the Morison’s equation. The results achieved in this project are consistent with results achieved by Lambrakos in his comparison of the Wake Model predictions with measured forces (actual loads) from the Exxon Pipeline Field Measurement Project (PFMP). The Wake II Model lends itself to easy computer application such as MathCAD so ftware and will also reduce the overall construction cost of cylindrical offshore structures such as pipelines and risers.
Frictional Effects in a Low Speed Polar-Axis Solar Tracker
Authors: Agee John T. , Jimoh Adisa A.
Published: October 2011

Sensorless solar tracking involves the low speed tracking of the direction of sunrays across the sky. At such low speeds, frictional effects in the electromechanical drive system of the tracker become amplified, and can significantly affect the accuracy of tracking. This paper models the frictional effects in low speed solar tracking and shows that the frictional effects lead to significant positional error during tracking. Further results show that, a class of controllers derived from strictly positive real (SPR) transfer functions, could be used to eliminate the positional tracking error due to frictional effects.