bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of Porous Alumina Fabricated by Ceramic Injection Moulding Using Environmentally Friendly Binder
Authors: Surawatthana J. , Chuankrerkkul Nutthita , Buggakupta Wantanee
Published: June 2012

Porous alumina (Al2O3) ceramics were fabricated by powder injection moulding process. The feedstocks, composed of 44 50 vol% of Al2O3 powder, could be prepared using a composite binder, consisting of polyethylene glycol (PEG) and polyvinyl butyral (PVB). Debindings were carried out using a combination of water leaching of the PEG and thermal debinding of the PVB. It was observed that the removal of the PEG was fast at the initial stage and more than 90 wt% of the PEG could be removed within 4 hours. Sintering was performed in argon atmosphere at 1600 °C. The sintered specimens had apparent porosity in range of 26-32 %, depending on the feedstock compositions. The flexural strength values were in range of 90-140 MPa while the hardness values were in range of 5-9 GPa. It was found that both the strength and hardness of the specimens were increased with increasing powder loading.
Thermal Analysis of Chitosan-Lactate and Chitosan-Aluminum Monostearate Composite System
Authors: Yodkhum Kotchamon , Phaechamud T.
Published: June 2012

Chitosan possess many attractive properties for applying as biomaterials. For some application, biomaterial devices have to be sterilized using high temperature, e.g. stream sterilizing process. However, thermal degradation behavior of chitosan has been reported previously. Many researchers have attempted to improve thermal degradation behavior of chitosan by synthesize chitosan derivatives or blending chitosan with other polymers or additives. However, chitosan derivatives found to be less thermal stability than chitosan itself. On the contrary, adding some lipid additive could improve thermal stability of chitosan. In this study, protecting effect of aluminum monostearate (Alst) on thermal stability of chitosan was investigated employing thermal analysis techniques, e.g. thermogravimetry (TG), differential scanning calorimetry (DSC) and hot-stage microscope. Lactic acid solution (2% w/v) was used as solvent for dissolving chitosan. Chitosan solution, named as chtiosan-lactate (CL) and chitosan solution contained 2.5% w/w Alst (CLAlst) were prepared and fabricated into sponges using freeze drying technique. Degradation temperature of CLAlst system investigated from TG was shifted to the higher temperature comparing that of CL which indicated that Alst could improve thermal stability of chitosan after processed as biomaterial. From DSC result, small endothermic peak was observed around 60-70°C for CLAlst whereas that of CL did not exhibit any peak. Melting behavior of the sponges observed under hot-stage microscope was demonstrated that chitosan was decomposed whereas Alst dispersed in chitosan backbone was gradually melted.
Drug-Loaded Pectin Microparticles Prepared by Emulsion-Solvent Evaporation
Authors: Sriamornsak Pornsak , Konthong S. , Burapapadh K. , Sungthongjeen Srisagul
Published: June 2012

The aim of this study was to develop the pectin-based microparticles by emulsion-solvent evaporation technique. The effects of concentration and type of pectin and addition of glutaraldehyde on size, size distribution, drug crystalline state and drug dissolution from microparticles were investigated. The results showed that a model drug, indomethacin, could be encapsulated in microparticles. Higher molecular weight of pectin caused a larger in size of microparticles than the lower one. A high degree of esterification is preferred to stabilize the pectin microparticles. The powder x-ray diffractograms showed that all microparticles led to amorphous products while their physical mixture still showed the crystalline state of drug. Drug dissolution from the microparticles containing indomethacin and pectin was increased, resulting from the formation of an amorphous solid dispersion. Addition of glutaraldehyde, however, resulted in slower drug dissolution, compared to the formulations without glutaraldehyde or drug alone.
Design of Shellac-Based Film with Improved Mechanical Properties through Composite Formation with Clay
Authors: Piyawatakarn P. , Sriamornsak P. , Nunthanid J. , Limmatvapirat C. , Limmatvapirat Sontaya
Published: June 2012

The objective of this study was to explore the effect of clay on mechanical and related properties of shellac (SHL) films. The SHL was dissolved in ammonia solution, and then casted into the film. For SHL-clay composite film, bentonite (BTN) which is popular clay in pharmaceuticals, was added and well dispersed before casting. The SHL and SHL-BTN composite films were then comparatively characterized. The results showed that SHL-BTN composite films were stiffer than SHL films since the modulus was 3 times higher. However, the percent elongation was lower, suggesting the more fragility of composite film. The drawback of composite film was solved by adding of polyethylene glycol. The percent elongation of composite film, puncture strength and modulus were higher than those of SHL film. However, BTN may be dispersed in the film without any interaction of shellac molecules since the FTIR spectrum of SHL-BTN composite film did not change as compared to physical mixture of SHL and BTN. The knowledge gained should provide an alternative way of modification of shellac properties for coating.
Proteoglycan Analogues for Ophthalmic and Orthopaedic Applications
Authors: Tighe B.J. , Bramhill J. , Campbell D.C.
Published: June 2012

The successful development of biomaterials is increasingly influenced by biomimesis essentially the use of biological structures as design templates. This approach has been used here in the design of injectable systems for the nucleus of the intervertebral disc, corneal inlays and intraocular lenses (IOLs). The strategy is based on the use of C-linked sulphonates to mimic the O-linked sulphate groups that are the hydration drivers in proteoglycans. The elastic modulus of the materials can be tailored for specific applications.
The Ultimate Biodegradation of the Starch Based Biodegradable Plastics
Authors: Intaraksa Parichai , Rudeekit Yositar , Siriyota Pongsaks , Chaiwutthinan P. , Tajan M. , Leejarkpai Thanawadee
Published: June 2012

The objective of this work was to investigate the ultimate aerobic biodegradation of poly (lactic acid) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT), with and without the starch according to ISO14855-1: 2004. The degree of biodegradation for 120 days of PLA, PLA/starch (50:50), PBAT and PBAT/starch (50:50) were 85.75%, 93.60%, 23.71% and 73.32%, respectively. The degree of biodegradation of cellulose was 70.20% under the same conditions. For PLA, a lag phase was observed during the first twenty days of the testing. This result indicated that there was no ultimate biodegradation occurred at the beginning of testing period of PLA. However, no lag phase was observed in the biodegrability testing of the PLA/starch (50:50), PBAT and PBAT/starch (50:50). Moreover, the addition of starch into the polymers leads to higher biodegradation rate of the materials. Finally, the biodegradation results were confirmed by thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). It was found that the results of TGA, FT-IR and SEM were in good accordance with the biodegradation results.
The Influence of Cyclodextrin and pH on the Solubility of Ketoprofen
Authors: Samprasit W. , Rojanarata Theerasak , Akkaramongkolporn Prasert , Ngawhirunpat Tanasait , Opanasopit Praneet
Published: June 2012

Cyclodextrin complexation and pH adjustments have been reported as useful tools to increase the solubility of drug. The aim of this study was to investigate the influence of both cyclodextrin and pH on the overall solubility of ketoprofen. β-cyclodextrin (β-CD) and hydroxypropyl β-cyclodextrin (HP-β-CD) were used for the preparation of inclusion complex by shaking method in aqueous solution at pH 2, 5, 7 and 10. It was found that the solubility of ketoprofen significantly increased with increasing pH and cyclodextrin concentration, showing AL type phase solubility diagram. However, the apparent stability constant of complex (KC) was found to decrease with increasing pH due to the decreased affinity of ionized drug to cyclodextrin cavity. The ionization of ketoprofen increased when the pH was raised, corresponding with its higher zeta potential. The result indicated that the solubility of ketoprofen could be improved by using a combined approach of pH adjustments and complexation with cyclodextrin. Moreover, the unionized drug that was formed by pH adjustments interacted with cyclodextrin more strongly than the ionized drug.
Development of Ketoprofen Microemulsion for Transdermal Drug Delivery
Authors: Worachun Narumon , Opanasopit Praneet , Rojanarata Theerasak , Ngawhirunpat Tanasait
Published: June 2012

The aim of this study was to prepare microemulsion for transdermal drug delivery of ketoprofen (KP). The physicochemical and chemical properties of microemulsion were evaluated. The microemulsion were composed of isopropyl myristate (IPM) as oil phase, water, PEG40-hydrogenated castor oil (Cremophor® RH40) as surfactant and PEG400 as co-surfactant, and the surfactant: co-surfactant ratio used was 1:1. The viscosity, droplet size, pH, conductivity of microemulsion and skin permeation of KP through shed snake skin were evaluated. The particle size, viscosity and conductivity of microemulsions were in the range of 172-468 nm, 234.82-1067.35 cP and 6.80-20.87µS/cm, respectively. The ratio of IPM and surfactant mixture played an important role on KP loading capacity of microemulsions formulation and skin permeation of KP. While amount of surfactant increased, the loading capacity of KP increased, but the skin permeation of KP decreased. The results suggested that the novel microemulsion system composed of IPM, water, Cremophor® RH40:PEG400 (ratio 1:1) can be applied for using as a transdermal drug delivery carrier.
Investigation of Antibacterial Properties of Soda Calcium Borosilicate Glass Doped with TiO2
Authors: Sornsanit K. , Pudwat Sayan , Limsuwan Pichet , Kaewkhao Jakrapong
Published: June 2012

The borosilicate glasses doped with TiO2were prepared by the melt-quenching technique in compositions SiO2B2O3CaO-Na2O, and investigate their physical, optical and antibacterial properties. The result found that, after dope TiO2, the density was decreased. The densities of glasses are not depending on TiO2concentration. The cutoff wavelength was shifted to longer wavelength with increasing of TiO2concentration from 360 nm (undoped TiO2) to 395 nm at 7.5 % of TiO2concentration. TheE. coli. was decreased due to TiO2generates reactive oxygen species from photocatalysis phenomena.
Antimicrobial Activity of Newly Formulated Propolis Cream
Authors: Puttamayutanon P. , Trongarom W. , Janta N. , Ruengsiri S. , Kamjaisai S. , Chantawannakul P.
Published: June 2012

The aim of this study was to determine the antimicrobial activities present in newly formulated propolis cream and compare them with an organic solvent extract of propolis. The antimicrobial activities were examined using the agar well diffusion method and measuring the growth inhibition zone. The skin pathogen gram-positive organisms used were Micrococcus luteus, Staphylococcus epidermidis, Streptococcus pyogenes, Methicillin resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus. The propolis cream and extracts showed satisfactory inhibitory effects on the microbial growth.
Efficacy of Activated Carbon In Situ to Oil Palm Frond Paper for Active Packaging on Mechanical Properties
Authors: Thongjun N. , Jarupan Lerpong , Pechyen Chiravoot
Published: June 2012

Oil palm frond pulp (OPF) was blended with activated carbon for the purpose of active packaging in this preliminary study. It was aimed to investigate the effect of in-situ activated carbon on physical and mechanical properties of the pulp handsheets made from OPF. Testing of property performances of the resulted handsheets included density, moisture content, thickness swelling, folding, tensile strength, %elongation, stiffness, and modulus of rupture. Ultimately, the intention is to use for prospected active packaging for fresh produce. OPF pulp was prepared by the kraft process. The pulp stock was mixed with different proportions of activated carbon (0, 10, 20, and 30% w/w). The results showed that an increased proportion of activated carbon decreased density and thickness selling, but had no effect on moisture content.
Surface Treatment on Low Density Polyethylene with TiO2 Nano-Particles for Packaging Printing
Authors: Phokhaphaiboonsuk D. , Jarupan Lerpong , Pechyen Chiravoot , Nandhivajrin C.
Published: June 2012

The surface of low density polyethylene (LDPE) film was modified by coating with titanium dioxide (TiO2) nano-particles in epoxy resin in order to increase the surface energy. Epoxy/TiO2 yielded a bridging effect between TiO2 particles and polymer matrix, while epoxide group played a role as dispersant. The surface energy of coated film and uncoated film were compared. The modification of LDPE surface used different two TiO2 nano-particles in size (100 and 150 nm) and weight loadings (0.5, 1.0, 2.0 and 4.0 %wt/wt). The results showed that the surface energy of LDPE films were raised up after the coating but it was still lower than the commercial film. Changes in colors and the agglomeration of TiO2 particles caused by non-homogeneity to the epoxy resin were detected on the film surface. To this end, it can be concluded that the TiO2 coating improves the printability on LDPE film.
The Force Analysis on the Shaft of Electric Vehicle Based on Unigraphics
Authors: Wang Tao Fen
Published: June 2012

Although the mechanical analysis on electric shaft is a complex and trival analysis process, the analysis method of using UG makes the force analysis of electric shaft single, rapid, accurate, and we realized the graphical level and improve the design efficiency and design quality. Through establishing a mathematical model, this paper analyzed the force characteristic of shaft according to the mathematical model.Then analyzed the force of connecting in rod automobile engine by using 3D software Unigraphics (UG).Fianlly we get the force data, whch provides theoretical basis and technical support for the axis force research of electric vehicle.
Researches on Fractal Features of Graphite Porous Materials
Authors: Liu Qi , Hu Ya Fei , Wang Qi Li
Published: June 2012

The mercury porosimetry experiment has tested three different kinds of porosity graphite and the microscopic structure of impregnation antimony materials, and has calculated the corresponding fractal dimension by using the Menger model. The results show that: the main pore diameter of the graphite materials is in the interval of , most of which can be filled by impregnation antimony, and graphite and impregnation antimony materials both have the fractal characteristics. Graphite materials also have the dual fractal characteristics. Its fractal inflection point aperture is about 1μm, and the fractal dimension (3.05 ~ 3.25) of the small pores (φ≤1μm) is less than the one (3.71 ~ 3.95) of the large pores (φ>1μm). The reason why existing the dual fractal characteristics is that the size of the pore formation mechanism is different. Impregnation occurs mainly in the range of large pores, characteristics of which is an important factor to influence the quality of impregnation materials. The material formula is the main factor to influence the large pores and an important guarantee to improve the quality of impregnation products.
Mechanics Transmission and Analysis of the Stress Measurement and Control System of the Fracture Traumatic Cross-Section
Authors: Zhu Jian Min , Li Xiao Ru , Li Hai Wei
Published: June 2012

In allusion to the measurement and control system of the fracture traumatic cross-section stress, because of the manufacturing error and installation error of its mechanical components, the axial and radial force of the indicating value of the dynamometer exists at the same time, and the radial force will damage the fracture healing. According to the mechanical structure of the measurement and control system of fracture traumatic cross-section stress, analyzed the mechanics transmission, and established the mechanics transfer model of the stress measurement and control system. Based on the force method typical equations, acquired the unknown force and torque of the measurement and control system. Take the radial force of the indicating value of the fracture two-dimensional dynamometer into the mechanics transfer model expression, thus obtain the result of the fracture traumatic cross-section affected by the radial force that applied by the stress measurement and control system, and then adjust the size and direction of the radial force on the fracture trauma section applied by the stress measurement and control system, and reduce the negative effect of the radial force on fracture healing.
Grey New Information Unbiased GOM(1,1) Model Based on Opposite-Direction Accumulated Generating and its Application
Authors: Luo You Xin , Liao De Gang
Published: June 2012

Monotonically decreasing sequence data for the use of traditional modeling methods to establish the grey model accuracy is not high, grey GM (1,1) model, there is a deviation, the model does not meet the conditions for coordination, generated using the definition of reverse accumulation, full use of system information and unbiased grey GM (1,1) model parameters of the model derived formula, based on reverse incremental build new interest generated by an unbiased model grey GOM (1,1) model for the grey model provides a new method. Data processing examples show that the model's practicality and reliability.
Effects of Bias on the Bonding Structure and Mechanical Property of a-C:H Films Deposited by MFPUMST
Authors: Jiang Hui , Dai Hai Yang , Huang Ning Kang
Published: June 2012

Hydrogenated amorphous carbon (a-C:H) films on silicon wafers were prepared by middle frequency pulsed unbalanced magnetron sputtering technique (MFPUMST) at different substrate bias under the methane-argon mixed gases. Raman spectra show that the sp3 fraction in a-C:H films increases with increasing substrate bias voltage from 0 to 100 V, and then decreases when the substrate bias above 100 V. Nano-hardness for these films prepared under different substrate bias voltage show that nano-hardness increase with increasing substrate bias voltage from 0 to 100 V, and then decrease from 100 up to 200 V. The results above indicate that the sp3 fraction in the prepared a-C:H films is directly related to nano-hardness, therefore, substrate bias voltage is an important factor for influence on the bonding configuration of the deposited a-C:H films. The related mechanism is discussed by sub-plantation model in this paper.
A Study on Explosion Characteristics of Toner Powder
Authors: Li Xiu Li , Fan Li , Xie Hong Yong , Wang Jing Wei
Published: June 2012

Toner powder is an important constituent of a toner cartridge for a laser printer and has potential hazards of combustion and explosion because of its physicochemical characteristics. In this paper, physicochemical, combustible and explosive characteristics of hpQ2612A toner are investigated experimentally. The mean size of the toner powder is about 2.45 μm and it has several organic groups such as carboxyl group, hydroxyl group and carbonyl group which make the toner dust much easier to combust. The TG-DSC curves show that the toner dust is combustible and the combustion process starts at about 368 . The dust explosion characteristics of the toner dust were, respectively: MIE=5~30 mJ, Pmax=0.74 MPa, (dP/dt)max=100.5 MPa/s, LEL=40~50 g/m3. These results reveal that the toner powder is a dangerous industry dust and has the possibility to make tragedy such as combustion or even explosion.
Segregation Diagram of a Mixture of Particles with Different Sizes and Densities
Authors: Shimamura Shuji , Takahira Takanori , Suga Shota , Tamura Hajime , Senda Yasuhiro
Published: June 2012

Segregation in granular materials has been studied by means of Monte Carlo simulation. The mechanism of segregation in a binary mixture of particles with different sizes and densities has been investigated for shaking and rotating processes in two-dimensional space. From the simulations we have obtained the segregation diagrams for shaking and rotating. These diagrams show what type of segregation occurs in a binary mixture with given values of the size ratio and the density ratio. From the diagrams we can also know what conditions are required to avoid segregation and mix uniformly a mixture of particles with different sizes and densities by the shaking and fast rotating processes. It is also shown that in the shaking process there is a critical size-ratio above which large-sized particles always segregate upward irrespective of the density ratio. Some implications of the segregation diagrams for shaking and rotating obtained by our simulations are discussed with consideration for real granular materials.
Investigation of Flow Channel Geometry and Draw-Down in Funnel-Flow Bins and Stockpiles
Authors: He Yan Yan , Roberts Alan W. , Prigge Jan Dirk
Published: June 2012

Over the past 50 years, a strong foundation for the professional discipline of bulk solids handling has been provided, but so far, the theories for predicting funnel-flow are still quite empirical. In most cases, only two-dimensional stress field models are applied, which overestimate the stable pipe or rathole dimensions defining the core of the funnel and lead to draw-down and live capacity determinations, which are too conservative. More recently, Roberts [ introduced a new, more realistic, hoop stress theory based on the three-dimensional stress state occurring in a rathole. To verify the validity of the new theory, the current research upon which this paper is based, involves an experimental study of rathole formation in laboratory scale model funnel-flow bins and gravity reclaim stockpiles. A two-dimensional laser line scanner is used to depict rathole profiles, while load cells and pressure sensors are applied to determine instantaneous loads and pressure conditions during filling, storage and discharge. Iron ore fines are used as the test material, with the test program including flat-bottom bins with different diameters as well as varying filling levels and outlet diameters and stockpiles with variable heights and outlet diameters. The tests demonstrate the capability of laser scanning to describe rathole profiles. In addition, the suitability of the load cells and pressure sensors to describe the relevant funnel-flow parameters is shown.
Preparation of Super-Fine Cerium Oxide Using Mechanically Chemical Method
Authors: Gu Zi Ying , Gu Hang Yu , Peng Xin Ke , Li Yong Xiu
Published: June 2012

The cerium oxide powder has been modified with mechanically chemical method. The effect of modifier, reaction time, calcine temperature, and amount of additives on the particle size, density, and hardness of super-fine cerium oxide was investigated. The complex super-fine cerium oxide powder was prepared, whose physical state and feature were characterized. The results show that modifier and powder may interact, which improves the properties of super-fine cerium oxide.
A Study on Grinding Rate of Mica Particles
Authors: Xie Hong Yong , Yuan Hao , Guan Jie
Published: June 2012

Grinding rate of mica particles by a planetary ball mill was studied by the measurement of specific breakage rate and breakage distribution parameter for different size ranges. The relationships between specific breakage rate and breakage distribution parameter with particle size were obtained from the measured results. The results show that grinding rate decreases fast as particle size decreases. Using integraldifferential equation for the mass fraction in grinding process with experimental obtained relationships of specific breakage rate and breakage distribution parameter with particle size, grinding process of mica particles are simulated by the 4thRunge-Kutta method, and particle size distribution between simulated and measured has been compared. The comparison results show that the specific breakage rate of mica particles was proportional to grinding time.
Direct Synthesis and Characterization of Ti-SBA-15 with Different Ti Precursors
Authors: Chen Sheng Wen , Qin Min Min , Yang Hai Feng , Xie Hong Yong
Published: June 2012

Titanium substituted SBA-15 mesoporous materials have been prepared by direct synthesis under hydrothermal conditions. Ti-SBA-15 was prepared by TiCl4 and Tetrabutyl titanate (TPOT) as titanium precursor. The synthesized materials were characterized by X-ray diffraction (XRD), UV-Vis spectrometer (UV-Vis), N2 adsorption/desorption, SEM etc. The results exhibited that the synthesis of mesoporous materials are ordered, and Titanium is tetrahedral and highly dispersed through the inside of SBA-15. Spherical particles of mesoporous have been synthesized by TPOT. The mesoporous materials synthesized by TiCl4 had non-uniform particle morphology. The titanium precursor TPOT incorporation in SBA-15 makes surface area increase due to make the pore walls slimmer. The titanium precursor TiCl4 had great influence of the particle morphology and pore characters and no influence on crystal structure.
Microbial Leaching of Copper from Waste Electronic Scraps
Authors: Xu Jin Qiu , Bai Jian Feng , Wang Jing Wei , Liang Bo , Cheng He , Guan Jie , Wang Li Jun
Published: June 2012

Microbial leaching was used to mobilize copper from two kinds of waste electronic scraps used as raw materials for printed wire boards. Both of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans used to solubilize copper from the samples. The experimental results demonstrated that the percentages of copper basically increased with decrease of sieve fraction of the samples. The green non-conductive coating of the waste electronic scraps was proved to have little effect on the leaching efficiency of both of the pure culture of Acidithiobacillus ferrooxidans and Acidithiobacil thiooxidans or their mixed culture. Acidithiobacillus ferrooxidans has larger solubilizing capability for copper than Acidithiobacillus thiooxidans.
Flow Characteristics of Gas-Solid Two-Phase Flow in Annular Pipe of Gas Drilling
Authors: Zhao Jun , Hu Shou Gen , Wang Peng Wang , Wu Chang
Published: June 2012

Air drilling technology has been widely used in the oil and gas exploration, coal, geothermal, geological exploration, nuclear industry and other fields due to its high drilling rate and low cost. However, the design of the pneumatic conveying system for the mineral detritus is still largely based on empiricism. The paper was set in the background of gas drilling, mainly studied the gas-solids two-phase flow characteristics in 90 degree bent annular pipe and backward-facing step of an annular pipe, which are very important parts of air drilling. They refer to the bent part and backward-facing step of an annular channel formed by the drill pipe and the borehole wall. A detailed numerical simulation and experimental studies were carried out for the flow structure and pressure losses of gas-solid two-phase in the annular pipe of gas drilling. Since a unified theory has not been developed for the two-phase flow in annular pipe, a lot of experimental work should be conducted. In the experimental research, the paper independently designed and built an annular pipe pneumatic conveying system with 90 degree bend and backward-facing step, including designing material screw feeder, material receiving hopper, pipeline, control system, data acquisition system, and etc. As known, many parameters, such as gas velocity, diameter and density of the particle, and solids loading ratio, can influence the conveying process. How these primordial influence factors act on the pressure losses of two-phase flow in annular pipe was analyzed in this paper. In the numerical simulation research, turbulent two-phase flow calculations were performed with a commercial CFD computer code referred to as FLUENT to study the gas-solid two phase flow in the sections of backward-facing step and 90 degree bent pipe respectively by using Euler-Lagrange method. The RNG κ-ε model and stochastic tracking were involved in the calculation of turbulence dispersion of two phases. The discrete phase model was performed for the solid phase. In the end, the numerical study 3-D results were translated to 1-D results using the standard averaging transformation to compare with experimental results. Predicted results obtained for pressure drop and velocity variations in full developed flows in the cases examined are in good qualitative agreement and are not in quantitative agreement with experimental data. The deviations between the simulations and experimental data lie in the range of 20%-30%. These results suggest commercial CFD codes such as FLUENT can be used productively for investigations into gas-solid two-phase flow phenomena and as an aid in pneumatic conveying design. The studies of the two-phase flow characteristics in the paper will contribute to reliable determination of the optimal condition of pneumatic conveying in gas drilling.
Particle Size Analysis by Laser Diffraction Method Using Reference Particles
Authors: Mori Yasushige , Yoshida Hideto , Masuda Hiroaki
Published: June 2012

The particle size analysis (PSA) by laser diffraction (LD) method can be used for monitor or control of particulate process, because it has the advantages of shorter measurement time and good repeatability, and a variety of commercial instruments is available. However particle size distribution (PSD) measured by LD method depends a great deal on not only optical detector configuration and calculation procedure but also on the system of sample loading into the measuring zone. From this fact, the validation of PSA by LD method should be done using reference particles (RP), whose size distribution is better to have a range over one decade of size, according to ISO 13320-1. For this purpose, the Association of Powder Process Industry and Engineering, Japan (APPIE) distribute the spherical barium titanate glass particles as RP of JIS Z 8900-1, whose size ranges are 1 - 10 µm (MBP 1 - 10), 3 - 30 µm (MBP 3 - 30) and 10 - 100 µm (MBP 10 - 100). This paper shows why LD method needs to check its performance by using RP, and then reports the results of the round robin test of two kinds of RP (MBP 1 - 10 and MBP 10 - 100) and silica RP candidate with 0.1 1.0 µm size measured by LD instruments, which was conducted by the Technical Group of Measurement and Control in APPIE. PSD results measured by LD instruments were almost same as each other for both RP samples. MBP 1 - 10 sample was well dispersed in water without detergent, but a few drops of detergent sometimes needed for dispersing MBP 10 - 100 sample. For MBP 1 - 10 sample, PSD by LD method was slightly smaller than that measured by scanning electro microscopy (SEM) or electro sensing zone (ESZ) methods. For MBP 10 - 100 sample, PSD by LD method agreed well with that by SEM or ESZ methods. Silica sample can be supplied to the users as the dry powder, which can be re-dispersed in water with small amount of surfactant. From the results of the round robin test using silica sample, PSD measured by LD method roughly agreed with EM method.
Macrograph Grain Size Analysis Method of Tight Gravel-Rock Huang Lina
Authors: Huang Li Na
Published: June 2012

We develop the research on macrograph grain size analysis method of tight gravel-rock, in allusion to the difficulty in conducting the grain size analysis due to difficult dissolution of oversized rock particles with adamant lithology in deep-seated natural gas conglomerate reservoir in Daqing Songliao Basin. The research includes the establishment of coarse clastic grain grade scale, sample selecting, grain extraction, data processing method, and so on. This testing method meets the requirements of the grain size analysis of the coarse clastic rock with grain diameter more than 4000 micron, gives the features of the grain size distribution and provides references to deposition reservoir research.
High Speed Visualization of Pneumatic Conveying of Materials in Bypass System
Authors: Jones Mark Glynne , Chen Bin , Williams Kenneth Charles , Abu Cenna Ahmed , Wang Ying
Published: June 2012

Dense phase pneumatic conveying is preferable over dilute phase conveying in many industries as lower transport velocities are beneficial due to reduced attrition of the particles and reduced wear. However, dense phase conveying is critically dependent on the physical properties of the materials to be conveyed. For many materials which are either erosive or fragile, they do not exhibit the physical properties required to be conveyed reliably in a low velocity, dense phase flow regime. This can be serious problem in the food, chemical and pharmaceutical industries. One satisfactory approach which has been widely applied is the use of bypass systems. Bypass pneumatic conveying systems provide the capacity of transporting some materials that are not naturally suitable for dense phase flow. Bypass pneumatic conveying systems also provide a passive capability to reduce minimum particulate transport velocities. In this study, pneumatic conveying experiments were carried out in a 79 mm diameter main pipe with a 27 mm inner diameter bypass pipe with orifice plate flute arrangement. Alumina, fly ash and sand were conveyed in the tests. High speed camera visualization was employed to study the flow regimes of bypass pneumatic transport systems and investigate the mechanism of material blockage inhibition provided by these systems. For alumina and fly ash, it was found that particulate material blockages were inhibited in bypass systems due to the air penetration into the particulate volume as a result of orifice plate airflow resistance. For the bypass pneumatic conveying of sand, the splitting of a long plug into two smaller plugs was observed. One of the primary concerns of bypass system is the wear of the bypass line. Material such as alumina is inherently abrasive by nature. For internal bypass systems, there is limited ability to monitor the state of the inner bypass tube while in operation. The particle velocity in the pipeline has been measured from the high speed video of the flow. The experimental result also showed that the conveying velocity of bypass system is much lower when compared conventional single bore pipelines. Based on the models developed for the assessment of service life of pneumatic conveying pipelines, the thickness loss of the bypass pipe has been estimated. It has been estimated that for a 3mm bypass tube wall thickness, a wear hole is created in approximately 2.5 years for a particle velocity of 3 m/s and 4 months for a particle velocity of 10 m/s.
Grain Gradation Design for Al2O3-MgO-C Refractories Based on Close Packing Theories
Authors: Zhao Shu Mao , Yang Wei , Sun Jie , Xie Zhi
Published: June 2012

In this study, raw materials in five different commercially available size ranges were mixed to prepare blank for Al2O3-MgO-C refractories. In the light of close packing theory, the optimization model for getting the optimum grain gradation was founded. And optimum ratio for raw materials of different size and distribution character was concluded by solving the model to obtain closest packing. The result shows that stacking density and tap density of the blank came from the particle mixture with optimized grain gradation reached 1.46 and 1.70g/cm3 individually, both were higher than those of the blank made of mixture according to empirical grain gradation. And the microstructures observation result indicated that the voids among aggregate particles in the refractory came from the mixture with optimized grain gradation were separated into small and discrete ones while they were bigger in the refractory produced following empirical grain gradation.
Local Mechanical Properties and Microstructures of Alloy52M Dissimilar Metal Welded Joint between A508 Ferritic Steel and 316L Stainless Steel
Authors: Wang Hai Tao , Wang Guo Zhen , Xuan Fu Zhen , Liu Chang Jun , Tu Shan Tung
Published: June 2012

The local mechanical properties and microstructures in a real dissimilar metal welded joint (DMWJ) of nuclear power plant were investigated. Results show that the distributions of mechanical properties in the DMWJ are very inhomogeneous. Especially in the three interface regions of A508/Alloy52Mb, Alloy52Mb/Alloy52Mw and Alloy52Mw/316L, the inhomogeneous characteristics are most prominent, and some local softening and hardening zones are formed. This non-uniform distribution on mechanical properties is mainly caused by the different microstructures in the DMWJ. The local dramatic variations in mechanical properties and local mismatch effect in the softening and hardening zones have significant effects on macroscopic fracture mechanics parameter, local crack initiation and growth behavior. But they are not considered in present structure integrity assessment codes and Leak-Before-Break (LBB) analysis. For assessing integrity and conducting LBB analysis on the DMWJ accurately, it is necessary to determine the local mechanical properties and their local mismatch ratios. In addition, the new integrity assessment and LBB analysis methods based on local damage and fracture need to be developed.
Luminescence Characteristics of Ba0.5Sr0.5TiO3:Prx, Aly Powders Synthesized by Citrate-Nitride Combustion Process
Authors: Yu Dao , He Wei , Liu Qing Feng , Zhong Hong Mei , Liu Qian
Published: June 2012

Ba0.5Sr0.5TiO3:Pr powders co-doped with and without Al were synthesized by citrate-nitride combustion process. To investigate the effect and mechanism of Al dopant, samples with various Al3+ and Pr3+ content were prepared. The excitation and emission spectra were detected. Enhanced red emission around 613 nm was obtained by Al addition. Moreover, an emission at 491 nm was observed. Substitute situation of Pr3+ ions in the lattice was discussed. And the mechanism of energy transition was explained by the model of an intermediate charge transfer state.
Removal of Impurities in Aluminum by Uses of Fluxes
Authors: Liu Chen , Hu Zhi Liu , Zeng Jian Min
Published: June 2012

A new method for removal of impurities in pure molten aluminum has been presented in this paper. The basic principle of this method is that the molten fluxes are forced to inject into the molten aluminum under counter-gravity, creating strong vortex to mix fully with the molten aluminum. In this way, the impurities in the aluminum will transfer into the flux because of the absorption of the flux to the inclusions. As the result, the molten aluminum is purified. The experiments were carried out for pure aluminum combined with the flux (40wt.% NaCl，30wt.% KCl，10wt.% NaF and 20wt.%Na3AlF6). The results show that after 3 purifying cycles (6 minutes), the inclusion contents decreased from 2. 1% to 0.35%, a removal rate of 83.3%; and hydrogen concentration decreased from 0.37ml/100gAl to 0.12ml/100gA, with hydrogen removal rate being 68%.
Studies on CUI of Carbon Steel in Simulation Environment Containing Chloride and Sulfur at 80°C
Authors: Tang Jian Qun , Gong Jian Ming , Jiang Ying Jie
Published: June 2012

Corrosion under insulation (CUI) is a localized corrosion occurring at the interface of a metal surface and the insulation on the metal surface. In order to explore the mechanism of CUI, some tests were conducted on 20 # carbon steel under insulation dripping different testing solution at 80°C in an experimental simulation device for CUI. Corrosion behaviors were analyzed by weight loss methods and other methods. The results showed that CUI rate of 20# carbon steel increased with NaCl concentration. The addition of sulfur and the decrease of pH promoted corrosion. The pits and small cracks were found on the corroded metal and the bonding between products and matrix was strong.
The Critical Cooling Rate of Fe-Based Mono-Sized Spherical Particles with Fully Glassy Phase
Authors: Li Ying , Dong Wei , Fu Yi Fan , Tan Yi , Miura Ayako , Kawasaki Akira
Published: June 2012

A new method to evaluate the critical cooling rate, Rc of Fe-based metallic glass alloy was proposed and discussed. [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy particles were prepared with narrow size distribution and high sphericity by Pulsated Orifice Ejection Method in Ar, He and 50%Ar+50%He mixed atmosphere, respectively. Phase transition of a particle from amorphous to amorphous-crystalline and fully crystalline occurred with the increase of particle diameter. Rc of the formation of fully amorphous phase was estimated to be in the range of 700-1100 K/s, lower than that measured by time-temperature transformation diagram of bulk metallic alloy. No change of Rc occurred in Ar, He or 50%Ar+50%He mixed atmosphere, which proved it an effective method to evaluate the critical cooling rate of Fe-based metallic glass alloy.
Effect of Rare Earth (La) on Dynamic Softening and Precipitation of Low Carbon High Niobium Steel
Authors: Fang Qi , Song Wen Zhong , Sun Wei , Jin Zi Li , Ren Hui Ping
Published: June 2012

Rare earth (RE) has purification, denatured mixture and micro alloy function in steel. High Nb containing in steel can expend austenite non-recrystallization region, improve rolling temperature and lower equipment load. Effect of RE on dynamic recrystallization of low carbon high niobium steel is investigated by using thermal simulation experiment in this paper. Experimental results show that dynamic recrystallization does not occur in two test steel below 1000°C. RE elements can increase dynamic recovery beginning strains, refine and disperse M/A organization and change precipitates into small triangle shape.
Effects of Microstructure and Texture on the Mechanical Properties of Extruded Mg−Gd−Nd−Y−Zn Alloy
Authors: Hou Xiu Li , Sun Xu , Wang Li Min , Cao Zhan Yi
Published: June 2012

In present work, the Mg−Gd−Nd−Y−Zn alloy sheets were prepared by hot extrusion technique. The microstructure, texture and mechanical properties of the extruded alloy were investigated. After hot extrusion, the alloy reveals a greatly refined microstructure due to the dynamic recrystallization. The coarse eutectic phases were crushed into small particles during extrusion process, which brings a promotion of grain refinement. A weak basal fiber texture was obtained in the as-extruded alloy owing to the influence of RE (rare earth) alloying elements. The as-extruded alloy exhibits mechanical anisotropy that the strengths and elongations in the extrusion direction are both higher than those in the transverse direction. And this behavior does not change with increasing temperature. It results from the weak texture and the distribution of eutectic phase particles in the alloy sheet. Through isothermal aging treatment, significant strengthening is achieved in the peak-aged alloy, and the mechanical anisotropy still exists.
Mission Reliability Simulation and Verification of Electrification System of Conventional Submarines
Authors: Yang Jian Jun , Li Fang , Yang Chuen Huei
Published: June 2012

Electrification is an important mission of conventional submarines. By regarding the electrification system of conventional submarines as a phased cold standby system, a mission reliability analysis model of the multi-phase storage system with element failure following exponential distribution is built to solve the issue of precise calculation of electrification mission reliability of conventional submarines. The correctness of the analytical mode has been verified by the analytical results and simulation results.
Anti-Air Missile Warhead with Multiple Explosive Forged Projectiles
Authors: Shi Lian Yan , Song Wen Yuan , He Xin , Zhang Zi Bin
Published: June 2012

Owing to the increase in the types of battle field targets and the improvement of their velocity, flexibility and protection ability etc., the anti-air missile warhead with multiple explosive forged projectiles goes upon the stage. The warhead is based on multiple explosive forged projectiles with an alternate angled and layered structure. Thanks to its distributed explosive way and measures of safety barrier and anti-interference, all energy of this warhead can be controlled to release intensively in the dynamic damage volume, and damage the air target seriously even at a long distance. So it is used to attack the armor-protected targets in the air, and slso accomplish the task of distributing antimissile and antiaircraf ammunition etc.
The Effect of Dynamic Vulcanization on Mechanical, Rheological, Thermal Properties and Morphology of ABS
Authors: Cui Yong Yan , Zhao Zhen Lun , Chao Ai
Published: June 2012

The effect of dynamic vulcanization on mechanical, rheological, thermal properties and morphology of ABS were studied in this paper. And the effect of shear stress, shear rate on melt rheological behavior were discussed. The results showed that: the melt of dynamic vulcanization modified ABS was pseudoplastic fluid, and its apparent viscosity was increased. Tensile strength, notched impact strength of dynamic vulcanization modified ABS increased gradually, and the melt flow rate decreased gradually .
Simulation of the 45t Converter Tilting Torque
Authors: Yin Yu Liang , Li Pei Zhen
Published: June 2012

Tilting torque of the converter is one of the fundamental and most important parameter. Many factors affect the calculation of converter tilting torque, especially furnace structure. By applying the 3D-CAD to calculate the converter tilting torque, we make a dynamic analysis and get the tilting torque, which provides theoretical basis for its improvement.
Finite Element Analysis and Framework Improvement of the Truck Frame
Authors: Wang Yi Jun , Ren Hong Juan , Sun Qi , Lu Jia Lin
Published: June 2012

Based on the way of the Finite Element Method (FEM), this paper researches on the three dimensional frame of the truck by analyzing the frame's relevant data including safety factors, maximum stress, maximum displacement position, strain. Through the analysis on the FEM computation results, the frames framework improvement design are supplied. Finally, for testifing the feasibility and practicality of improved frame, this paper simulated frame working under three different conditions which are the full-loaded condition, the right-side load condition and the back-side load condition, and warranted the final summary by contrasting measured relevant data
The Mathematics Model Research and Analysis of Vibrating Fluidized Classification Technology of Kernel and Husk Separation Machine
Authors: Zhang Lin , Zhang Qi Zhi , Xu Hong Wen
Published: June 2012

For improving the stability of kernel and husk separation machine of rapeseed, we had done some experimental research about vibrating fluidized classification technology. Based on experimental dates we had built the mathematics model and analyzed the classification effect influenced by the amplitude, the frequency and the material thickness and their interaction .The results indicated that when we maintained installation angle α = 0o and vibration direction angle β =108o of the vibrated fluidized bed, the best optimized combination of factors was the amplitude x1 = 1.87mm, the frequency x2 = 52.53Hz and material thickness x3 = 22.36mm.