bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Thermal Plasma Assisted Catalytic Oxidation NO over Mn-Co-Ox Catalysts at Low-Temperature
Authors: Li Kai , Tang Xiao Long , Yi Hong Hong , Ning Ping , Ye Zhi Qing , Kang Dong Juan , Song Jing Hao
Published: November 2010

Mn-Co-Ox catalyst was prepared by the co-precipitation method. The most active catalysts were obtained with a molar Co/(Mn+Co) ratio of 0.1. The results showed that over this catalyst, NO oxidation conversion reached 56% at 150°C and 59% at 175°C with a high space velocity of 35000h-1. Their surface properties were evaluated by means of scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The process of Non-thermal plasma-assisted catalytic oxidation of NO under low-temperature was studied. And the NO conversion could reach 71% with the Non-thermal plasma-assisting at 125°C when the input voltage was 30V. The increasing activities at low temperature (50-150°C) were more apparently higher than high temperature by plasma. And the low-temperature catalytic activity of the catalyst was increased with the increase of the input voltage.
Microstructure and Electrical Properties of Nd2O3-Doped TiO2-Ta2O5-Based Capacitor-Varistor Ceramics
Authors: Wang Tian Guo , Qin Qun , Zhou Dong Jian
Published: November 2010

A low-voltage TiO2 capacitor-varistor ceramics doped with Ta2O5 and Nd2O3 was systematically researched. The effect of Nd2O3 on the microstructure, nonlinear electrical properties, and dielectric properties of TiO2-based ceramics was investigated. It was found that an optimal doping composition of 99.20 mol% TiO2-0.10 mol%Ta2O5-0.7 mol% Nd2O3 was obtained with low breakdown voltage of 8.5 v/mm, high nonlinear constant of 4.0, ultrahigh electrical permittivity of 1.07× 105 and low tanδ of 0.39. In view of these electrical characteristics, the ceramics of 99.20 mol% TiO2-0.10 mol%Ta2O5-0.7 mol% Nd2O3 is a viable candidate for capacitor-varistor functional devices. The theory of defects in the crystal lattice was introduced to explain the nonlinear electrical behavior of the Nd2O3-doped TiO2-based varistor ceramics.
Effects of Silane Coupling Agent Treatment on Properties of PMN/EP Composites
Authors: Shi Min Xian , Zhang Ming , Huang Zhi Xiong , Qin Yan
Published: November 2010

The PMN/EP composites were prepared by resin casting method from PMN powder pretreated with silane coupling agent KH-550. The microstructure of the PMN/EP composite was observed by SEM, the damping property and dielectric property of the composite were investigated by dynamic mechanical analyzer and impedance analyzer respectively. In the composite prepared with PMN powder pretreated by 1.5% silane coupling agent, much epoxy resin fragment is attached in the surface of PMN particles. When the silane coupling agent concentration is 1.5%, the composite shows the best damping property. Dielectric analyses suggest that the dielectric constant of the PMN/EP composite decreases with the increase of silane coupling agent content, however the dielectric loss increases with the increase of silane coupling agent content.
Corrosion Behavior of Cold-Spray Aluminum Coating in Marine Environment
Authors: Zhu Qing Jun , Wang Kai , Wang Xin Hong
Published: November 2010

Aluminum coatings were prepared by cold spray on mild carbon steel Q235. Scanning electron microscopy shows that the bond zone has good bonding between the substrate and the coating and the coatings consist of interlocked particles. The corrosion behaviors of the coatings in marine environment were studied by electrochemical methods. Free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements show that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coating and some of the substrate has been corroded. Corrosion only can happen on the coating surface and specific deeper sites, where Cl- can penetrate through pores. Cold spray aluminum coatings can protect the substrate from corrosion in marine environment.
Environmental and Uncertainty Assessment: Hazardous Industry Waste as Aggregate in Cement Production
Authors: Hong Jing Lan , Li Xiang Zhi
Published: November 2010

A life cycle assessment was carried out to estimate the environmental impact of industry waste as aggregate in cement production. To confirm and add credibility to the study, an uncertainty analysis was also carried out. Results showed the impact seen from climate change, human toxicity, marine eutrophication, marine ecotoxicity, and freshwater eutrophication categories had an important contribution to overall environmental impact, due to energy use and direct emissions from clinker and limestone production stages. The most significant substances contribute to the climate change is CO2 to air; for the human toxicity, it is Hg to air and Mn to water; for the marine eutrophication and marine ecotoxicity, it is nitrate and Ni to water, respectively; for the freshwater eutrophication, it is phosphorus to water. Increasing electricity recovery rate, optimizing the raw material consumption for clinker production are highly recommended to reduce the adverse impact on the environment, and therefore reduce the pressure on the environment from dramatically increased hazardous industry waste disposal.
Effects of Cooling Rate on Morphology, Microhardness and Volume Fraction of Mg-Zn-Y Quasicrystals
Authors: Wang Zhi Feng , Zhao Wei Min , Li Hai Peng , Liang Chun Yong , Wang Yue Mei , Zhao Rui , Hur Bo Young
Published: November 2010

Mg72.5Zn26Y1.5 (at.%) quasicrystal alloys were investigated under different solidification conditions. The cooling curves were gathered by the multi-channel temperature acquiring system and the corresponding microstructures were analyzed. The morphology, microhardness and volume fraction of quasicrystals were detailedly studied. The effects of cooling rate on the above three aspects were also studied and the relation schema among them were exhibited. The results show that the quasicrystal size tend to smaller, its microhardness and volume fraction gradually increased, and the quasicrystal morphology changed from bulk polygon to petal-like and finally changed to plat X-shape with the elevated cooling rate from 2.3K/s to 181.2K/s. However, the quasicrystal nucleation will be restrained and amorphous matter will be created if the cooling rate exceed the critical point which make against the formation of quasicrystals with high performance.
Corrosion Resistance of Ternary Ni-Cu-P Coatings Prepared by Electroless Method on Carbon Steel
Authors: Sun Jie , Liang Ting , Ji Zhuang Zhou , Yan Rui , Meng Jin Hong
Published: November 2010

Ni-Cu-P coatings were prepared by electroless deposition method on carbon steel. The pH value and concentrations of cupric sulfate were studied to character the deposition rate, corrosion resistance of Ni-Cu-P coatings in 3.5% NaCl solution. From the results, it was shown that the deposition rate of Ni-Cu-P coatings increased with the increasing of pH value. The deposition rate speeds up until the deposition rate keeps stable when the pH value is about 8.0-9.0. When pH value was 7.5, the coatings showed good corrosion resistance. In the same conditions of solution compositions and technological conditions, the concentration of cupric sulfate must be lower than 2g/L if the copper and nickel altogether co-deposited. The minimal corrosion current and excellent surface state for the coatings can be obtained when the concentration of cupric sulfate was about 0.8 g/L.
Research on Hot Forging Process of C-Grade Steel Train Wheel by FEM
Authors: Wang Yan Ju , Fang Gang
Published: November 2010

C-grade steel has been widely used for parts of train wheel, train hook and other main parts with its predominant performance. That was mostly produced under high temperature and plastic deformation. In this paper, lots of experiments on the thermo-mechanical simulator Gleeble are operated, and the strain-stress curves under different deforming conditions are obtained. By the analysis of flow stresses under different conditions, the relationship among flow stress, temperature and strain rate as Sellers-Tegart equation is found, and the math model of C-grade steel at high temperature is established. The FEM code DEFORM has been used to simulate the forging process of train wheels. The numerical simulation results show that the first-stage forging parameters have quite important influence on the material distribution and the forge figuration of train wheel. It is necessary to determine the parameters in the pre-forming process reasonably. While, the influencing factors on the forming load are analyzed. The research shows that the heat parameters and the forging speed have influence on the forming load. Lower value of heat transfer coefficient and environment temperature, and lower speed at the ending stage could reduce the forming load significantly in the forging process of train wheels.
Effect of Additives on Characteristics of Poly(3-Hydroxybutyrate) Microspheres
Authors: Li Fan , Tian Feng , Liu Chang Jun
Published: November 2010

Poly(3-hydroxybutyrate) (PHB) based microspheres were prepared via double emulsion solvent evaporation using polyethylene glycol (PEG), poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), polylactide (PLA), poly(dl-lactic-co-glycolic acid) (PLGA) or chitosan (CTS) as the additive of wall polymers. It was found that additives had distinct effect on the properties of microspheres, such as the yield, drug loading, average diameter, crystallization states microstructure and surface morphological characters. PHB based microspheres using PEG as the additive had the lowest yield, the smallest average diameter, and the highest drug loading which reached 12.2% thereinto. At the same time it had the lowest crystallinity of PHB, and the diameter of the crystal particles was only 11.44 nm. It was feasible to prepare PHB based microspheres using PEG and PHBV as additives, which had relatively high protein loading but different microstructures and surface morphologies, and they were anticipated to have a good effect of controlled release.
Product Improvement Design Method Facing Modularization Disassembly
Authors: Wang Wei Lin , Zhang Jia Tai
Published: November 2010

From the perspectives of modularization disassembly, the influence of entity structure, function, motion and other factors of product brought to disassembly efficiency is elaborated. A way to improve design facing modularization disassembly is proposed. The time and cost of disassembly are checked by the proposed method through examples. Comparisons of disassembly evaluation before and after improvement are conducted based on the results. The general method to improve design is summarized. In terms of differences of repair probability of key parts in maintenance process, the improvement design criterion is put forward in the method, which improves the maintenance efficiency, reduces the maintenance cost and difficulty of disassembling operation and avoids data explosion of disassembly sequence because of too many parts.
Insecticidal Effects of the Insecticide Based on Porous Starch and Cinnamon Oil against Sitophilus zeamais
Authors: Li Li Xiu , Ge Ling Yan , Xue Ting , Li Xi Hong
Published: November 2010

We investigated that the bioefficacies of cinnamon oil and insecticide based on the mixture of porous starch and cinnamon oil. They were evaluated for their insecticidal activities and their mortality on adults of Sitophilus zeamais. Fumigant toxicity assayed by hanging in glass jars showed that these chemicals caused significant mortality of the test insect. Cinnamon oil evoked high repellent action and high fumigant toxicity (LD50 = 0.030μL/cm3) against adults of Sitophilus zeamais. The two concentrations of the new insecticide 0.030μL/cm3 (LD50) and 0.040μL/cm3 (the highest) lose their insecticidal activity after a minimum of 144h and 168h, respectively. These results suggest that cinnamon oil starch powder is the most effective insecticide, and could increase its efficacy for use as an alternative to synthetic insecticides.
Research on Nitrogen and Phosphorus Losses of Natural Composting Manure in the Northern Region of Erhai Lake
Authors: Huang Kai , Qu Guang Fei , Ning Ping , Gao Hua Ping , Jia Li Juan , Mao Wei Juan , Xiong Xiang Feng , Liu Su Juan
Published: November 2010

In recent years, the trend of eutrophication appeared in Erhai and the phenomena of small-scale algae outbreak has already happened. Erhai Lake pollution caused by many reasons.As an important factor of Erhai lake eutrophication, superabundant manure stacking at random in rural areas of Erhai Lake Basin and transference of the manure nitrogen and phosphorus into waterbody have attracted much attention of environmental researchers eutrophication of Erhai lake. The nitrogen and phosphorus contentes of livestock manure in the process of naturally composting were mensurated and the transference characteristics of the manure nitrogen and phosphorus were analysed. As a result, the regular pattern and loss type of livestock manure were advanced and advices about developing solid waste treatment facilities were brought forword.
Influence on Stucture of Layered Double Hydroxides with Different Methods Synthesis
Authors: Yu Hong Bo , Xu Bing , Bian Ling Xi , Gao Hong
Published: November 2010

This paper compares two methods for synthesizing a carbonate compound, Mg-Al-CO3 (Mg:Al=2:1), which is a layered double hydroxides (LDHs). The methods are mechanochemical method and hydrothermal method. The products characterized by XRD、SEM、FT-IR and TG-DTA. The results indicated that the target material was synthesized by different methods. The two kinds of well-crystallized materials with the same basal spacing d003=0.77nm, but their morphology were not same. The crystallite size of hydrothermal was larger than mechanochemistry.
Preparation and Properties of Modified PolyGram Nano-Microencapsulated Phase Change Materials
Authors: Tang Yi Da , Zheng Wen Heng , Tang Zhong Hua , Wang Ling
Published: November 2010

The nano-microencapsulated phase change materials were prepared ,with butyl stearate as core material, styrene-maleic anhydride copolymer (SMA) as dispersant and emulsifier, polyurea resin as shell material which was synthesized from monomer 2, 4- toluene diisocyanate (TDI) and diethylen etriamine (DETA),and was modified by glycerol, nanometer material(TiO2) as functional material. We have analyzed the compactness, stabilities, phase transition temperature, and bactericidal efficiency of microcapsules. The results show that the compactness properties and stabilities properties of the modified microcapsule, when the ratio of core material and shell material is 3:4, such as washing stability properties and thermal stability properties are obviously improved than that of non-modified, phase transition temperature rises from 23.2°C to 24.2°C,bactericidal efficiency of Nano-Micro-PCMs is 7~8 times more than that of separate using of nanometer material （TiO2）, modified polyurea Nano-Micro-PCMs may have extensive application prospects in the fields of architecture, textile and air-conditioning filtering materials.
White Electroluminescence from a Single Fluorene-Based Copolymer
Authors: Hou Qiong , Luo Jie , Luo Sui Lian , Zhu Hong , Shi Guang
Published: November 2010

White light emitting polymers were synthesized through incorporating of low-band gap red light emitting 4,7-di(4-hexyl-thien-2-yl)-2,1,3-benzothiadiazole (DHTBT) moieties into the backbone of a blue-light-emitting poly(9,9-dioctylfluorene) (PFO). Incomplete energy transfer from the blue electroluminescent PFO backbone to the red light emitting unit occurred by carefully controlling the relative content of the low-band gap unit DHTBT in the resulting polymers. Pure white light electroluminescence from a single polymer has been obtained in a device with a configuration of ITO/PVK/polymer/Ba/Al.The highest external quantum efficiency is 1.04% at the luminance of 249 cd/m2 for the white emitting polymer with color coordinates (0.30, 0.35) very close to the CIE coordinates for National Television System Committee (NTSC) standard white-light emission (0.33,0.33).
Processing and Characterization of Core-Shell PA12/Silica Composites Produced by Selective Laser Sintering
Authors: Wang Jian Hong , Bai Pei Kang , Zhang Zhen Lin , Li Yu Xin
Published: November 2010

Silica particles coated with PA12 by emulsion polymerization were used as fillers to reinforce PA12 based composites prepared by selective laser sintering (SLS). The influences of the treated and untreated particles on the sintering behavior and mechanical properties of the laser sintered specimens were investigated. It was found that there were many uneven holes in the untreated composites. However, for the treated composites, due to the silica particle surfaces treated by emulsion polymerization, the absorbance of laser was improved and the particles dispersed well in the polymer matrix; a full dense structure was obtained and the properties were enhanced, such as the tend strength increased 30%, the maximum value was 34MPa; the tensile strength increased up to 125%, the maximum value was 44.2 MPa, comparing to the unfilled PA12. Drawing from the results, it can be confirmed that a full dense structure can be obtained and the PA12 matrix was strengthened and toughened when the silica particles were coated with PA12 by emulsion polymerization.
The Effect of Different Solvent on the Microstructure of Gibbsite during Hydrothermal Treatment
Authors: Wang Jing , He Qi Na , Gao Zhen
Published: November 2010

Phase structure and micromorphology of gibbsite after hydrothermal treated in different solvents were studied. Results showed that there was a relationship between micromorphology and phase structure of as-synthesized product. The cubic slice-like boehmite microstructure can be obtained in water. The 3D flowerlike boehmite microstructure can be obtained in isopropanol or sodium carbonate solution. The global ammonium aluminum carbonate hydroxide (AACH) architectures assembled by the lathes can be obtained in urea solvent. Gibbsite can transform to boehmite after 12h hydrothermal treatment in water. In isopropanol or sodium carbonate solution, this time decreased to 6h. In urea solution, Aluminum hydroxide turned from gibbsite to the mixture of boehmite, gibbsite and AACH. Finally, AACH is synthesized. This procedure needs 24h.
Fabrication and Characterization of Al2O3/GdAlO3 Eutectic Ceramic In Situ Composite by Laser Zone Remelting
Authors: Su Hai Jun , Zhang Jun , Jiao Sha , Liu Lin , Fu Heng Zhi
Published: November 2010

In situ composite of Al2O3/GdAlO3(GAP) ceramic eutectic prepared by directional solidification is an interesting candidate for the manufacture of turbine blades because of its excellent mechanical properties. In the present paper, directionally solidified Al2O3/GAP eutectic in situ composite ceramics are manufactured by the laser zone remelting technique to investigate the rapid solidification process. The laser power and scanning rate necessary to carry out the ceramic melt growth is determined. The characteristic microstructure is investigated by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and X-ray diffraction (XRD). The as-solidified Al2O3/GAP eutectic presents an elongated colony structure consisting of only -Al2O3 and GAP phases with an oriented growth array. The eutectic spacing is strongly dependent on the laser scanning rate, rapidly decreasing to the sub-micron range for the samples grown at the highest rate. Besides, the formation condition and evolution of the particular microstructure of the composite during rapid solidification are discussed.
Effects of Rare Earth Elements on the Quality of Nugget in Aluminum Alloy Spot Welding
Authors: Dong Jian Tao , Luo Zhen , Zhou Lin Shu , Hao Jian
Published: November 2010

The strength and microstructure characteristics of the nugget in aluminum ally resistance spot welding were evaluated in this study with and without addition of rare earth elements Er, Ce. The strength was assessed using a small punch test mode and the microstructure was studied using an optical microscope, scanning electron microscope, and energy-dispersive spectroscope. Results indicated that the hardness and strength were increased about 10% after adding rare earth elements Er, Ce in the nugget. The grain of nugget zone was refined significantly. In the boundary and interior of the grain, a number of rare elements and its compounds were dispersed. This showed that parts of rare earth elements existed as solid solution in Al Matrix, part as the rare earth compounds. This improved that the elements not only can promote nucleation and refinement, but also can inhibit plastic deformation by hindering the dislocation movement. Thus they could play a strengthened role. The strengthening mechanism of the rare earth elements Er, Ce in the alloy nugget is mainly the second phase strengthening and fine grain strengthening.
Strength Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods
Authors: Liu Feng
Published: November 2010

The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the stress state of the composite laminates under unidirectional tensile force is analyzed. The strength criterion and damage mode are given based on the stresses of material principal direction. The three dimensional finite element models of the same laminates with non-penetrating damage repaired by two kinds of bonding methods are built. The strength criterion and the damage mode of the two kinds of repaired models are also given. The influence of the interlaminar stress is considered in these analysis models. It is showed that the three dimensional models can simulate the geometric and physical features of the real composite laminates. It is concluded that the original composite laminates and the repaired ones both damage first in the laminar whose second material principal direction coincides with the axial tensile force. The damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the mother laminates. After scarf bonding repair, the strength of the damaged laminates recovers up to about eighty-four percent. With additional surface patch, the strength of the damaged laminates recovers up to about eighty-nine percent. Surface patch can improve the strength of damaged laminates.
Study of Parameters and Technics for Chrome-Plating Texturing
Authors: Tan Yong , Sun Jie , Liu Chang Sheng , Yu Xiao Zhong
Published: November 2010

The generally textured techniques used in industry can make the roller surface fall off or damage by burning to form aculeate concave. The textured rollers produced by the method mentioned above have some disadvantage performances that include rapid roughness attenuation, limited use time and more concave. These disadvantages are not suitable for the formation of roughness on the cold roller surface. On account of high hardness and excellent wearable capability, the element chrome, which can be deposited on the cold roller surface, can increase the use life of textured cold roller enormously. In this paper, an experiment of DC superimposed pulse was performed to obtain certain roughness chrome textured and hemisphere-shaped chrome coatings. From the results, it was shown that the roughness and hardness of coating obtained by electroplating was 3.79μm at 850mA/cm2 and 1000 Hv respectively.
Hot Forming Analysis of Car Door Bar for Ultra High Strength Steel
Authors: Gao Yun Kai , Gao Da Wei , Deng You Zhi , Cao Wei
Published: November 2010

Ultra high strength steel plays an important role of light weighting in automotive industry. The hot forming simulation of car door bar is processed with 22MnB5 ultra high strength boron steel. FEM is built with the 12 nodes shell elements and MAT 106 is selected in LS-DYNA. The hot forming processes include two heat transfers. One is the process from the oven to the tools after the blank is heated. The other is the process after the blank contacts the tools. The hot forming simulation results are obtained by LS-DYNA. The results show that the thickness distribution, the forming limit and the maximum effective plastic strain and other performances attain to standards. It is proved that the hot forming simulation method is correct.
Loading and Unloading Split Hopkinson Tension Bar Technique for Studying Dynamic Microstructure Evolution of Materials
Authors: Huang Wen , Huang Zhong Wei , Zhou Xiao Qing
Published: November 2010

In order to investigate the microstructure evolution of materials, loading and unloading experiments with specimens deformed at different strains are required. In this paper, momentum traps were introduced for rendering the conventional Split Hopkinson Tension Bar suitable for loading-unloading experiment. The new technique allows a specimen to be loaded to a preset strain for post-test characterization. This technique was applied to study the dynamic mechanical properties of pure titanium. The results show that: 1) the twinning density of titanium increases rapidly as the strain increases. 2) The strength and ductility of titanium exhibited on the adiabatic curve are much smaller then those exhibited on the isothermal curve, which may be caused by the adiabatic heat generated during the transient deformation process.
Magnetic Properties of Fe-Co Films with Tuneable In-Plane Uniaxial Anisotropy Prepared by Electrodeposition
Authors: Yang Xu , Gong Lu Qian , Qiao Liang , Wang Tao , Li Fa Shen
Published: November 2010

Fe-Co soft magnetic films with tuneable in-plane uniaxial anisotropy were successfully electrodeposited onto ITO conductive glass. The influence of composition and electrolyte temperature on in-plane magnetic anisotropy field was investigated. Our results show that the in-plane uniaxial anisotropy can be induced by a magnetic field applied in the film plane during electrodeposition. Fe-Co films with various Fe content in the range from 35 at.% to 53 at.% were obtained and the magnetic anisotropy field was very sensitive to the composition. Moreover, the influence of electrolyte temperature on magnetic anisotropy field was investigated and it was found that the in-plane uniaxial anisotropy field can be tuned by varying the electrolyte temperature from 5 to 40 oC.
Organic Solvent Traces in Fibrillar Scaffolds for Tissue Engineering
Authors: Lederer A. , Harnisch C. , Bhattacharyya Debes , Fakirov S.
Published: November 2010

In the present study the amount of xylene remaining in fibrillar scaffolds after their manufacture has been estimated by means of Gas Chromatrography coupled to Mass Spectrometry (GC-MS). For this purpose model scaffolds of poly(ethylene terephthalate) (PET) comprised of microfibrils with diameters of ~1 µm or nanofibrils with diameters of 50-150 nm as well as microfibrillar scaffolds of poly(glycolic acid) (PGA) have been used. An extremely low initial amount of xylene has been found (< 20 ppm). The xylene amount dropped below 2 ppm after drying for 24 h in a vacuum at 80°C. The microfibrillar PGA scaffolds, initially containing more xylene (23.4 ppm), retained only 3.6 ppm after drying for 24 h. After drying for 48 h the amount of xylene in all the scaffolds studied reached the detection limits of the GC-MS apparatus (< 0.5 ppm).
Amorphous Calcium Phosphates
Authors: Dorozhkin Sergey V.
Published: November 2010

Amorphous calcium phosphates (ACPs) represent a unique class of biomedically relevant calcium orthophosphate salts, in which there are neither translational nor orientational long-range orders of the atomic positions. Nevertheless, the constancy in their chemical composition over a relatively wide range of preparation conditions suggests the presence of a well-defined local structural unit, presumably, with the structure of Ca9(PO4)6 – so-called Posner’s cluster. ACPs have variable chemical but rather identical glass-like physicochemical properties. Furthermore, all ACPs are thermodynamically unstable compounds and, unless stored in dry conditions or doped by stabilizers, spontaneously they tend to transform to crystalline calcium orthophosphates. Although some order within general disorder is the most distinguishing feature of ACPs, the solution instability of ACPs and their easy transformation to crystalline phases might be of a great biological relevance. Namely, the initiating role ACPs play in matrix vesicle biomineralization raises the importance of this phase from a mere laboratory curiosity to that of a key intermediate in skeletal calcification. Furthermore, ACPs are very promising candidates to manufacture artificial bone grafts.
An Interlocking Ligamentous Spinal Disk Arthroplasty with Neural Network Infrastructure
Authors: Boughton Philip , Merhebi James , Kim C. , Roger G. , Diwan Ashish D. , Clarke E. , Amanat Negin , Ho R. , Ruys Andrew John
Published: November 2010

An elastomeric spinal disk prosthesis design (BioFI™) with vertebral interlocking anchors has been modified using an embedded TiNi wire array. Bioinert styrenic block copolymer (Kraton®) and polycarbonate urethane (Bionate®) thermoplastic elastomer (TPE) matrices were utilized. Fatigue resistant NiTi wire was pretreated to induce superelastic martensitic microstructure. Stent-like helical structures were produced for incorporation within homogenous TPE matrix. Composite prototypes were fabricated in a vacuum hot press using transfer moulding techniques. Implant prototypes were subject to axial compression using a BOSE ® ELF3400. The NiTi reinforced implants exhibited reduction in axial strain, compliance, and creep compared to TPE controls. The axial properties of the NiTi reinforced Bionate® BioFI™ implant best approximated those of a spinal disk followed by Kraton®-NiTi, Bionate® and Kraton® prototypes. An ovine lumbar segment biomechanical model was used to characterize the disk prosthesis prototypes. Specimens were subject to 7.5Nm pure moments in axial rotation, flexion-extension and lateral bending with a custom jig mounted on an Instron® 8874. The motion preserving ligamentous nature of this arthroplasty prototype was not inhibited by NiTi reinforcement. Joint stiffness for all prototypes was significantly less than the intact and discectomy controls. This was due to lack of vertebral anchor rigidity rather than BioFI™ motion segment matrix type or reinforcement. Implant stress profiles for axial compression and axial torsion conditions were obtained using finite element methods. The biomechanical testing and finite element modelling both support existing BioFI™ design specifications for higher modulus vertebral anchors, endplates and motion segment periphery with gradation to a low modulus core within the motion segment. This closer approximation of the native spinal disk form translates to improvements in prosthesis biomechanical fidelity and longevity. Axial compressive strain induced within a TiNi reinforced Kraton® BioFI™ was found to be linearly proportional to the NiTi helical coil electrical resistance. This neural network capability delivers opportunities to monitor and telemeterize in situ multiaxis joint structural performance and in vivo spine biomechanics.
Monte Carlo Analysis as a Tool for Characterizing Uncertainty in Optical Calibration of End Standards
Authors: Farid Niveen
Published: November 2010

In this paper, Monte Carlo method (MCM) is used to analyze the uncertainty of optical calibration of end standards using both contact and non-contact techniques to validate the uncertainty values obtained by the conventional method, Guide to the expression of Uncertainty in Measurement (GUM). Number of trials (M=104) is simulated with the probability density function (pdf) for each quantity, and the comparison between the results of the MCM and the GUM shows good agreement which in turn validates the uncertainty values obtained by the conventional method. The statistical analysis, variables' distributions, and the output of each technique are discussed in detail.
The Study of Elastic-Plastic Fatigue Behavior of Nigerian-Rolled NST 37-2 Steel
Authors: Malomo B.O. , Ibitoye S.A. , Adekoya L.O.
Published: November 2010

The NST 37-2 steel represents about 75% volume of Nigerian-produced steel which is yet to be fully characterized for its fatigue behavior. Thus, its suitability for many applications is questionable. This paper presents a framework based on the theory of elasto-plasticity in order to make appropriate recommendations in this regard. Experimentally, tensile tests were carried out on test specimens to establish the baseline material properties of the steel in annealed, as-rolled, normalized and hardened/tempered conditions. Fatigue tests were then conducted at 60% Su; 70% Su and 80% Su of the test material and fractographic examinations on the test specimens were subsequently carried out. The frequency harmonic fatigue analysis was implemented in the ANSYS software environment for the numerical study. The elastic-plastic material property was described by the von Mises yield criterion, the flow rule of Prandtl-Reuss, and the kinematic hardening rule of Prager. The numerical results indicate with respect to rate-dependence fatigue behavior that the annealed test specimen is most resilient under cyclic deformation as compared with the normalized, hardened/tempered and as-rolled specimens respectively. The experimental and numerical results were found to be in close agreement and based on the general performance, the steel material is recommended for use in low cycle, quasi-static fatigue applications.
Design, Analysis and Experimental Evaluation of Photovoltaic Forced Convection Solar Dryer for the Tropics
Authors: Adelaja A.O. , Ojolo S.J.
Published: November 2010

The photovoltaic (pv) forced convection solar dryer comprises the solar collector, dryer and pv assemblies. It is designed for a continuous operation throughout the day. The direct solar irradiation is utilized during sunshine hours and it automatically switches power supply to the battery during cloud covers and non-insolation periods. The inclusion of a heat reservoir enables heat transfer to continue during this period. In this study, thermal and dryer analyses were done. Experimental investigations were carried out to evaluate the performance of the system by drying plantain chips. The useful power collected was found to be, 391.50W, collector efficiency, 65.6%, dryer efficiency, 39.6%, average drying rate during insolation, 0.0169kg/hr and total drying time was 23 hours. The maximum temperature attained was 55oC. The average drying non insolation period was 0.0112kg/hr. The capital cost is less than $350.
Optimization of Biodiesel Production from Jatropha Oil
Authors: Okullo Aldo , Temu A.K. , Ntalikwa J.W. , Ogwok P.
Published: November 2010

The most important factors that influence biodiesel production are temperature, molar ratio, catalyst amount, time and degree of agitation. This study investigated the effects of temperature, molar ratio and degree of agitation and their interactions on the yield and purity of biodiesel produced from Jatropha oil. Factorial design and response surface methodology (RSM) were used to predict yield and purity of biodiesel as functions of the three variables. Interactions of all the factors were found to be significant on both yield and purity responses. Temperature and molar ratio main effects were found to be significant on the yield whereas only temperature main effect was significant on the purity of the biodiesel. The optimum conditions of operations were; temperature of 54 oC, molar ratio of methanol to oil of 6:1 and stirring speed of 660 rpm. Using these conditions, biodiesel yield of 95% (wt) was obtained with a purity of 97%. This model can be used to predict the yield and purity of biodiesel from jatropha oil within the ranges of temperature (30 – 60oC), stirring rate (300 -900 rpm), and molar ratio (3 – 9 mol/mol) studied.
Assessment of Bentonite Influence on Hydraulic Conductivity of Lateritic Soil
Authors: Amadi Agapitus A. , Osinubi K.J.
Published: November 2010

Lateritic soils are pedogenic surface deposits which occur in vast areas of tropical and subtropical regions of the world and find use as construction material in diverse civil engineering aspects. But, the predominance of kaolinitic 1:1 lattice clay mineral and coating of the clayey constituents with sesquioxides limits the ability of the soil from achieving very low hydraulic conductivity, (k) required for some geotechnical/geoenvironmental structures. The present study investigates the influence of low percent bentonite on the hydraulic conductivity of a residually derived lateritic soil. Accordingly, the test programme involved specimens of lateritic soil - bentonite mixtures containing 0, 2.5, 5, 7.5 and 10% bentonite (by dry weight of soil) prepared at different compaction states (optimum, dry and wet of optimum content), compacted with British Standard Heavy, (BSH) compactive effort and permeated in compaction mould permeameter using falling head test method. Results indicate that reductions in hydraulic conductivity values ranged from 1 x 10-9 to 6.79 x 10-11 m/s (i.e. two orders of magnitude) as the percentage of bentonite increased from 0 to 10%. Soil mixtures with up to 5% bentonite content recorded the lowest k values at 2% wet of optimum moisture content, beyond which an increase in k followed. For soil mixtures containing 7.5 and 10% bentonite, a continuous decrease in k was observed. Furthermore, a non – linear relationship between log k and bentonite content was established. These results met or exceeded specification requirements for the aforementioned structures which therefore suggest that the potentials of lateritic soils as a geomaterial for the construction of hydraulic structures can be fully realized when treated with bentonite.
Simulating the Mechanical and Structural Properties of UltraSTEELTM Dimpled Sheet
Authors: Wang Chang J. , Sihra Tarsem , Mynors Diane J. , Nguyen Bac , English Martin , Castellucci Michael
Published: November 2010

The novel surface dimpling UltraSTEELTM process developed by Hadley Industries increases the strength of the final rolled products and enhances other product properties such as the load carrying capacity. The dimpled UltraSTEELTM sheet is used in steel framing, ceilings and other structural components. The mechanical properties and structural behaviour of the dimpled sheet are different from plain sheet due to non-uniformly distributed plastic strain and geometry of the dimples.
Design and Simulation of a Femoral Component Peg in Total Knee Replacement
Authors: Wang Chang J. , Shi Jun F. , Morgan Colin , Mynors Diane J.
Published: November 2010

Aseptic loosening of the femoral component is one cause of failure in total knee replacement (TKR). Inadequate bone stock in the distal femur after TKR, due to the stress shielding, was often found in revision of the femoral component. The pegs in the femoral component are used as an aid to the correct placement of the component but they also help to transfer the load to the diaphyseal part of the bone and improve stability. This paper investigates the influence of femoral component peg design on stress distribution and bone remodelling in the distal femur after TKR. Eight different peg designs were investigated and reported in this paper. The bone remodelling parameters in the distal femur are presented, compared and analysed. Results show that a slender peg is advantageous in TKR.
Path Planning for Vehicle with Constraint on Turning Radius among Obstacles
Authors: Wang Neng Jian , Zhang De Fu , Zhou Li Jie
Published: November 2010

A path re-planning method is proposed based on a discretization of the state space, aiming at finding a collision-free path for the vehicle which is capable of forward and backward motion when changes occur in the environment. A Control Set with Turning Radius Constraint (CSTRC) is formulated and the feasibility of paths in CSTRC is also proved out. The A* search is applied to produce a feasible path considering the distance and angle between the vehicle and the target pose. Path re-planning can be carried out efficiently when the environment changes. Simulation results demonstrate that the method realizes path re-planning effectively and the path satisfy the turning radius constraint.
Research of the Joint Workspaces and Kinematic Efficiency of Man-Machine Systems of Bicycles
Authors: Shyu Jenq Huey , Lai I Tsung , Chang Ta , Wang Yun Cheng , Lin Ta Wei
Published: November 2010

Bicycle design largely contradicts human motion, necessitating consideration of both the bicycle structure and the kinematic efficiency in the dimensions of the rider’s limbs, as well as human factor engineering, i.e. comfortability. By focusing on the kinematic model of 5-bar linkage and joints workspace, this study examines the most appropriate bicycle design and the riding posture to ensure that muscles can produce the effective moment and increase driving efficiency of a crank necessary. For upright, racing and recumbent bicycle types, assumptions are made regarding mobility analysis and the system of man-machine systems of bicycles estimated as well. Simulation results can identify the major dimensions of bicycle designing for different riders efficiently by inputting physical measurements of the rider and the angle range of driving force, subsequently increasing the riding efficiency to decrease the load of lower limbs of riders and satisfying ergonomic requirements of bicycle riders.
Enhancing the Ideality of Innovation by AD/TOC/TRIZ
Authors: Shi Dong Yan , Liu Shang
Published: November 2010

In order to enhance ideality of innovation by comprehensive application of all aspects which affect ideality, we propose a framework which embeds the theory of constraints and TRIZ into the customer domain, function domain and physical domain of axiomatic design. The dataflow is described from customer domian to physical domain through function domain in this framework, and a case study is used to shown the validation.
Effects of Temperature and Grain Refinement on Micro Simple Upsetting of Copper
Authors: Chang Chao Cheng , Kuo Wu Lu
Published: November 2010

This study uses simple upsetting processes of copper to investigate the effects of temperature and grain refinement on stress-strain behaviour. The equal channel angular extrusion (ECAE) and heat treatment techniques were applied to refine and control the grain size of copper in a range between 4 m and 46 m. The coppers were then machined to prepare the billets with 2 mm diameter and 3 mm height. To conduct the upsetting processes at elevated temperature, a forming system equipped with a heating device was also developed. The experimental results show that the copper billets with refined grains have higher strength than those with coarse grains prepared by annealing treatments. The grain refinement and the increase in forming temperature can improve material flow behaviors and thus lead to a better edge quality of the deformed workpiece.
Mathematical Modeling for the Prediction of Fuel Properties of Biodiesel from their FAME Composition
Authors: Mitra Soupayan , Bose P.K. , Choudhury Sudipta
Published: November 2010

The mono-alkyl esters of vegetable oils or animal fats, known as biodiesel have received significant attention as an alternative diesel fuel. In the present study fuel properties like viscosity, density and High Heat Value (HHV) of ten biodiesels namely Corn, Cottonseed, Linseed, Rapeseed, Safflower, Soybean, Sunflower, Mahua, Jatropha and Palm are predicted using their FAME ( Fatty Acid Methyl Ester) composition by regression analysis and the results obtained are compared and found to be in good agreement with reported literature values.
Thermal Stress Analysis of a Bi-Material Layered Structure
Authors: Her Shiuh Chuan , Lin Chin Hsien , Yeh Shun Wen
Published: November 2010

Thermal stress induced by the mismatch of the thermal expansion coefficients between dissimilar materials becomes an important issue in many bi-layered systems, such as composites and micro-electronic devices. It is useful to provide a simple and efficient analytical model, so that the stress level in the layers can be accurately estimated. Basing on the Bernoulli beam theory, a simple but accurate analytical formulation is proposed to evaluate the thermal stresses in a bi-material beam. The analytical results are compared with finite element results. Good agreement demonstrates that the proposed approach is able to provide an efficient way for the calculation of the thermal stresses. It is shown that thermal stresses are linear proportion to the ratio of thermal expansion coefficients between the two materials. Parametric studies reveal that thermal stresses in each layer are decreasing with the increase of thickness, and are increasing with the increase of Young’s modulus ratio between the two materials.
Reinforcement of Polyamide 66 with Polyoxometalates Nanoparticles through the In Situ Sol-Gel Method
Authors: Cheval Nicolas , Xu Fang , Gindy Nabil , Brooks Richard , Zhu Yan Qiu , Fahmi Amir
Published: November 2010

This paper investigated the influence of the nanoparticles on the thermal and mechanical properties of PA66 and various nanocomposites containing different weight fraction of polyoxometalate nanoparticles were prepared. The structural features of the nanocomposite are characterised using TEM, ATR-FITR, DMA and TGA. The results show that nanoparticles, around 5.5 nm in size are well-dispersed inside the polymer matrix. The physical interaction between PA66 and the POM nanoparticles led to a significant effect on the thermal and mechanical properties of PA66. Dynamic mechanical analysis (DMA) revealed a considerable change in the storage modulus of the nanocomposite. With only 1wt% of POM, the storage modulus of PA66 at 25oC is enhanced by 45%. Furthermore, the thermal stability of the nanocomposite is also enhanced, possibly owing to the absorption of oxygen by the nanoparticles. The results demonstrated that the obtained nanocomposites, via the combination of the excellent mechanical and thermal properties of PA66 with the intriguing optical, electrical and chemical properties of POM, were promising for catalytic, energy storage, memory devices, automobile and construction applications.
Novel Touch-Trigger Probe for Coordinate Measuring Machines
Authors: Karuc Emre , Dolen Melik
Published: November 2010

A novel touch-trigger probe system is proposed in this paper. The probe houses the stylus shaft on a special diaphragm spring that is exclusively designed with the utilization of Finite Element Analysis (FEA). In the probe system, Giant Magneto-Resistive (GMR) sensors are employed to measure the motion of the stylus shaft in the principal directions. The proposed (and implemented) probe is tested on a three-axis CNC electrical discharge machine (EDM) and the results acquired from those experiments are discussed. The preliminary work presented in this paper demonstrates the capabilities of GMR based probing technology in dimensional metrology.
Damping Responses of Viscoelastic Composite Material Structure
Authors: Muhammad Iqbal Sabir , Guo Wan Tao , Liu Er Bao , Li Li
Published: November 2010

The work reported in this paper describes the behavior and prediction of damping properties of the 3D composite laminated engine mount shell structure. The shell structure has a shape of box with four vertical and two horizontal plates with the thickness of 15mm and 20mm respectively. For more accurate prediction of the structural behavior, many researchers have incorporated the time dependent property of the material into their field of studies. In this article the finite element approach utilizes the concept of viscoelastic damping, which is carried out by direct integration. This paper describes the potential application of composite material as a damper device because of its damping, high stiffness and low weight properties, which favor the use as engine mount in submarine and ships where weight is the highest priority.