bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of Lightweight Oilwell Cements
Authors: Sauki Arina , Juanda Muhammad Ilham , Azizi Azlinda , Asadullah Mohammad , Tengku Mohd Tengku Amran , Ghazali Nurul Aimi , Alias Nur Hashimah
Published: August 2015

Drilling through depleted zones and weak formation can prove troublesome since the fracture resistance reduces from its normal boundary [1]. To successfully drill a hole section requires the selection of a low density cement slurry to prevent loss circulation while not exceeding the fracture resistance of the formations exposed. Large number of loss circulation will greatly impact the drilling cost and rig time. This research is focusing on the performance studies of lightweight oilwell cements using foam and cenosphere as the lightweight agents. All tests were conducted according to API Recommended Practice 10B-2. Three performance tests have been conducted such as density test, free water test and compressive strength test. The comparison was made at different percentage of lightweight agents e.g. 10, 20, 30 and 40 percent by weight of cement (%BWOC) respectively. The findings show the performances of formulated foam cement and cenosphere cement are within API limit. However, foam cement can reduce the density of set cement in about 8% greater than the cenosphere cement.
Characterization of Groundnut Husk Ash (GHA) Admixed with Rice Husk Ash (RHA) in Cement Paste and Concrete
Authors: Ogork Egbe Ngu Ntui , Uche Okorie Austine , Elinwa Augustine
Published: August 2015

This paper investigates the effect of Groundnut Husk Ash (GHA) blended with Rice Husk Ash (RHA) in cement paste and concrete with a view to improve its suitability as a supplementary cementing material. The GHA and RHA used were obtained by controlled burning of groundnut husk and rice husk, respectively in a kiln to a temperature of 600 °C, and after allowing cooling, sieved through sieve 75 μm and characterized. The effects of GHA admixed with 10 % RHA on cement paste and concrete were investigated at replacement levels of 0, 10, 20, 30 and 40 %, respectively by weight of cement. Fresh concrete grade 20 of mixes made with partial replacement with GHA admixed with 10 % RHA in the order as above were tested for workability and hardened concrete tested for compressive, splitting tensile and flexural strengths at curing ages of 3, 7, 28, 60 and 90 days in accordance with standard procedures. The result of the investigations showed that GHA was of low reactivity and RHA was more reactive, with combined SiO2, Al2O3 and Fe2O3 content of 26.06 % and 80.33 %, respectively. The use of GHA admixed with 10 % RHA increased consistency, initial and final setting times of cement, but decreased linear shrinkage. The workability, compressive strength, splitting tensile strength and flexural strength of concrete decreased with increase in GHA-RHA content. However, 15 % would be considered as the optimum for structural concrete.
Numerical Study on Uniaxial Compression Failure of Brittle Material with a Single Flaw
Authors: Tian Jia Shen , Zhao Cheng
Published: August 2015

Numerical investigations on failure process of rock-like materials with a single flaw were carried out under uniaxial compression based on the fracture analysis software: Fracture Analysis Code in Two Dimensions (FRANC2D/L). The change of the displacements and stress distribution were recorded around the crack. Comparative analysis is made among samples containing different angled flaw, which has great influnce on the process of crack initiation and propagetion, and with the increase of flaw angle from 30° to 75°, peak strength of the specimen increases linearly, basically. Which are in good agreement with those of experiments.
Lattice Boltzmann Modeling of the Effective Thermal Conductivity for Complex Structured Multiphase Building Materials
Authors: Hussain Mazhar , Ahmad Shakeel , Tao Wen Quan
Published: August 2015

The effective thermal conductivity is an important parameter used to predict the thermal performance analysis of complex structured porous building materials. The observation of porous structure of building materials on REV (representative elementary volume) scale showed that pores can be classified into meso and macro pores. In contrast to the traditional models usually used for the (macro-meso) pore connection , a new numerical random generation macro-meso pores (RGMMP) method, based on geometrical and morphological information acquired from measurements or experimental calculations, is proposed here. Along with proposed structure generating tool RGMMP a high efficiency LBM, characterized with the energy conservation and appropriate boundary conditions at numerous interfaces in the complex system, for the solution of the governing equation is described which yields a powerful numerical tool to obtain accurate solutions. Then present model is validated with some theoretical and experimental values of effective thermal conductivity of typical building materials. The comparison of present model and experimental results shows that the proposed model agrees much better with the experimental data than the traditional theoretical models. Therefore, the present model is not limited to the described building materials but can also be used for predicting the effective thermal conductivity of any type of complex structured building materials.
Frictional Loss of Prestress Caused by Locally Deflected Tendons in Prestressed Concrete Girder Bridges
Authors: Shin Kyung Joon , Kim Yun Yong , Lee Hwan Woo
Published: August 2015

Prestressed concrete girder bridges are one of the most widely used bridges in the world because of their excellent construction feasibility, economic efficiency, serviceability, and safety. In certain situations, however, the prestressing tendon is supposed to be bent locally, and this leads to the loss of prestress force. This kind of prestress loss is not considered in the design and construction processes. This study shows that prestress loss occurs at the locally bent tendon, and that a 2% maximum of prestress loss occurs at the locally bent tendon, due to eccentricity.
The Colorants Effects of Fe2O3 on Borosilicate Glasses Prepared from Subbituminous Fly Ash
Authors: Rachniyom W. , Ruangtaweep Yotsakit , Boonin Kitipun , Phachana K. , Kaewkhao J.
Published: August 2015

In this work, the subbituminous fly ash (SFA) in Thailand has been investigated for their compositions and crystal structures. Borosilicate glasses were prepare from SFA , B2O3, Na2O and various concentration of Fe2O3 by melt quenching technique. The results have shown that the chemical composition comprised with SiO2, Al2O3 and Fe2O3. The crystal structures of SFA were raised of mullite and quartz phases. The density and refractive index values of glasses were found to increase with increasing of Fe2O3 concentrations. The hardness values have been decreased with increasing of Fe2O3 content. The absorption spectra are corresponding to ferric and ferrous ions in wavelength of 440 nm and 1,050 nm and the color of glasses are green to yellow.
A Demonstrated Net Zero Energy Building in Thailand: The Way for Sustainable Development in Buildings
Authors: Wongwuttanasatian Tanakorn , Soodphakdee Denpong , Malasri Narinporn , Triratanasirichai Kittichai
Published: August 2015

Net Zero Energy Building (Net ZEB) concept has been applied to make a selected building as a self-energy provider. The building was partly modified to reduce its energy consumption using several energy efficient technologies such as wall material, insulator, VRF air condition unit, solar lighting, LED light bulbs, etc. While, electricity served into the building was generated by solar energy (PV panels). The monitored data over one year have proved that this build can generate the electricity more than its energy demand. This is a good achievement of Net ZEB in Thailand.
Analysis on Energy Performance of Educational Facility by Composition of Double Glass
Authors: Shin Yoon Seok , Kim Gwang Hee
Published: August 2015

Korean energy consumption accounts for about 40 percent in the architecture. Especially, Heat loss of the windows is about eight times larger than the wall or roof. In addition, the structures older than 20 years were designed with no consideration of the energy perspective, and they have low energy efficiency compared with the newly introduced structures, which leads to extreme energy consumption. Therefore, this study was conducted for the purpose of engergy performance analysis according to window type in educational facilities. This study we medeled the university library in Autocad Ecotect Ananlysis program, 3D modeling. It calcualted data that the air layer thickness has about 3.9 times more impact that the glass thickness in composition of double glass. As the result of this study, the need for the remodeling and renovation of the obsolete library in order to reduce its excessive energy consumption was highlighted.
The Effect of Mechanical Stress and Surface Tracking of 22 kV Cable Spacer
Authors: Nilbunpot Nutsopin , Suksri Amnart
Published: August 2015

Surface tracking is one of the causes that degraded the property of cable spacer. This research investigates about the mechanical stress and surface tracking performance of 22 kV cable spacer. Sample were tested according to the surface tracking under IEC 60587 standard under modified condition by and addition of the mechanical weight on the surface of pure epoxy resin sample. The mechanical load use were 0 kg and increase from 5 kg until 15 kg. The results showed that mechanical stress has affected the surface degradation of an insulation performance when the mechanical load is increased combined with high electrical field.
Thermal Conductivity and Specific Heat Capacity of Different Compositions of Yttria Stabilized Zirconia-Nickel Mixtures
Authors: Abbas Muhammad Rabiu , Noor Alias Mohd , Rajoo Srithar , Ahmad Norhayati , Basheer Uday M. , Sah Muhammad Hanafi Md
Published: August 2015

Ceramic-metal composites also known as functionally gradient materials (FGM) are composite materials which are fabricated in order to have a gradual variation of constituent materials’ thermal and mechanical properties so as to have a smooth variation of the material properties in order to improve the overall performance and reduce the thermal expansion mismatch between ceramic and metal. The objective of the study is to determine the thermal properties of various percentage composition of Yttria stabilized zirconia-Nickel mixtures for application as thermal barrier coating materials in automotive turbocharger turbine volute casing. Specific heat capacity of different percentage composition of ceramic-metal powder composite were determined using DSC822 differential scanning calorimeter (Mettle Tolodo, Switzerland) at temperature ranges between 303K to 873K. While the thermal conductivity of the different percentage composition of ceramic-metal composite structures were determined using P5687 Cussons thermal conductivity apparatus (Manchester, UK) which uses one-dimensional steady-state heat conduction principle. The results have indicated that the specific heat capacity of the FGM increases sharply with an increase in temperature while the thermal conductivity of the FGM decreases with an increase in temperature. These results strongly agree with the theoretical and experimental values as well as the rule of mixtures obtainable in literature, which indicated the suitability of these FGM materials for thermal barrier coating applications.
Experimental Verification of Effect of Adhesive Layer Thickness Used for Strain Gauge Mounting
Authors: Subrahmanya K. , Vadivuchezhian K. , Chockappan N.
Published: August 2015

Strain measurement from the strain gauge is partially affected by carrier and adhesive materials and their thickness. Effect of adhesive layer thickness has been addressed in this paper. Well characterized tensile experiments have been conducted using Al 6061-T6 specimens attached with strain gauges at mid length of the specimen and strain gauges are attached with different materials namely epoxy and polyurethane to understand the effect of adhesive layer thickness in strain measurement. The strain at a location has been noted for one particular adhesive layer thickness value (0.13 mm) and similar experiments have been carried out with different adhesive thickness values (0.16 mm, 0.18 mm and 0.26 mm). The results obtained from experiments have been compared with analytical results from Basic Strength of Materials approach. Good agreement is seen between the experimental and analytical results. It has been observed that the thickness of the adhesive layer plays significant role for getting accurate strain.
The Mechanical Properties and the Influence of Parameters for Metallic Closed-Cell Foam Subjected to High-Strain Rates
Authors: Lord Charles E. , Huang Zhen
Published: August 2015

As the trend for lighter more efficient structures continues, the requirement for alternative materials follows. One material that has gained attention more recently is porous metallic foam. One drawback to these materials is that there is limited pedigree and understanding of their performance. As with all materials, the use of metallic foam for structures requires knowledge of its mechanical properties; including at high-strain rates. The focus of this paper is to determine the compressive mechanical properties and the influencing parameters for AISI 4340 steel closed-cell foam under high-strain rates (776s-1 to 3007s-1). ANSYS commercial finite element code is used to simulate a closed-cell sample under a split Hopkinson pressure bar test. In this paper the pores are considered to be spherical in shape for simplification while various parameters such as the pore size, the number of pores, the distribution of pores, and the strain rate are varied. Each of these parameters gives this material a unique response which is presented in this paper.
Recycled Plastic Quality Indicator Development Using Material Testing Results and Radar Chart
Authors: Gabriel Djoko Sihono , Soemardi Tresna Priyana , Zagloel T. Yuri M. , Kiswanto Gandjar
Published: August 2015

Quality of recycled plastic is usually below than its virgin material. Status of quality compared to its virgin material quality helps producers and consumers to ensure viability of the material both as a manufacturing product as well as a raw material. A set of material testing result table accompanied with radar chart of its ratios proposed as a tool in representing quality indicator of a recycled plastic. An easy identification of lower and lowest quality and also better quality in certain material characteristics help producers and consumers to make a fast evaluation and further decision related to recycled plastic quality improvement and its proper utilization as raw material.
Microstructure, Texture and Property of Interstitial-Free (IF) Steel after Ultra-Fast Annealing
Authors: Cai He Long , Mou Jun Sheng , Hou Zi Yong
Published: August 2015

In this paper, common continous annealing (CCA) and ultra-fast annealing (UFA) were carried out on a cold-rolled interstitial-free (IF) steel, respectively. The microstructure of the annealed IF steel was characterized by means of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The mechanical property was examined using tensile test. The optimum annealing process parameters were then obtained. The results showed that, the recrystallization occurs at the temperature in the range of 780-830°C. The fraction of equiaxed grain increases with the annealing temperature increasing. The well combination of mechanical properties and formability was obtained when the IF steel annealed at 820°C, which was the result of the fine dispersed second phase particles. {001} texture was absent in the whole thickness of all the annealed IF steels. In addition, the strongest γ texture was found, and this was a potential way to improve the deep drawability of annealed steel sheets.
Experimental Study of the Fatigue Crack Propagation and Overloading Retardation in TA2 Plate
Authors: Li Hui Fang , Hong Yuan , Qian Cai Fu
Published: August 2015

In this paper, I+II mixed mode notch-crack fatigue propagation in titanium alloy steel TA2 was tested with the emphasis on the crack mode transition and retardation under constant amplitude loading or overloading. Finite element method was employed to calculate the stress distribution at the crack tip in order to explain the crack growth behavior. It is found that after initiation from the crack tip, the new formed crack propagates in a mode I form, regardless of the magnitudes of the inclined angle of the crack and the overloading applied. The relationship between the fatigue crack growth rate and mode I stress intensity factor range was calculated. After overloading, crack initiation and propagation will be significantly slowed, or in other words, there exists overloading retardation. Calculation shows that after overloading, a plastic zone with residual compressive stress is formed which is responsible for the retardation of the crack growth rate. Micro-morphologies of the crack growth path and the crack fracture surface were also observed and analyzed.
Effect of Pass Deformation on the Microstructure and Properties of Aluminum Alloy Anodes for Fuel Cell Application
Authors: Tang Yan , Liang Shu Quan , Li Hui Zhong , Zhang Yong
Published: August 2015

he effect of pass deformation on the microstructure of Al-Mg-Sn-Bi-Ga-In alloy anode was investigated by using SEM, TEM, and EBSD. The results show that when controlling the rolling deformation at 40%, the segregation phases on the Al alloy matrix was the best distributed for the reason of dynamic recrystallization procedure. The electrochemical and anti-corrosion results show that uniform distribution of segregation phase will improve the related properties of Al alloy anode. After optimizing the rolling procedure, the Al alloy anode has more negative electrode potential of about -1.585V(vs.Hg/HgO) and lower hydrogen evolution rate of 0.092mL/ (min·cm2)
Effect of Heat Treatment on the Resistivity and Mechanical Property of Low-Pressure Semi-Solid Die Cast Aluminum Alloy Wheel
Authors: Wang Rui , Meng Ling Qi , Zhang Heng Hua
Published: August 2015

Study the property and resistivity of Low-pressure semi-solid die casting ( LPSSDC) aluminum wheel hub after heat treatment. The Brinell hardness has reached more than 100HB in all position. Tensile properties at inner rim and outer rim are both reached 280MPa. The result of resistance analysis on LPSSDC aluminum wheel hub is below. The resistivity of the material is only influenced by the supersaturated solid solution (SSSS), GP zone, metastable phase β 'and stable phase β (Mg2Si). The resistivity has a decline during aging 0-0.5h and 0.75-8h, and an increasing during 0.5-0.75h. The resistivity remains stably when the decomposition of the solid solution achieved a dynamic balance after 8h aging time.
Research on Mechanical Characteristic of Micro-Nano Structure TaC Ceramic by Nanoindentation
Authors: Shao Tian Tian , Cai Xiao Long , Wang Jie Fang , Zhong Li Sheng , Zhao Na Na , Xu Yun Hua
Published: August 2015

Micro-nanostructure tantalum carbide (TaC) ceramic was prepared on grey cast iron matrix by the combined process of casting and heat treatment. The theoretical foundation of the nanoindentation technique was introduced in detail, and hardness/modular–displacement curve was received from continuous stiffness measurement (CSM). The results show that, elastic modulus (E) and hardness (H) variation with impression depth depend on size effect and matrix effect. There is no impression pile up effecting on hardness value. It was iron (Fe) existing in micro-nanostructure TaC ceramic during heat treatment , which is the main reason of improving creep property of the TaC ceramic. Study on micro-nanostructure TaC ceramic with high hardness, high elastic modulus and good creep property is meaningful to the application in the area of engineering.
Effects of Rotating Magnetic Field on Microstructure and Properties of Bi-Containing Hypereutectic Al-Si Alloy
Authors: Si Yi
Published: August 2015

In the present paper, based on Bi-containing hypereutectic Al-20%Si alloy, a rotating magnetic field was used, the microstructures of the alloy have been observed and analyzed by optical microscope and scanning electronic microscope, and its wear-resisting property was measured. The influence mechanism of rotating magnetic field on the microstructures and properties of the alloy has been discussed. Research results show that exerting a rotating magnetic field in the hypereutectic Al-20%Si alloy drastically decreases the amount of primary Si phase, only some tiny bulk Si exist and the amount of needle eutectic Si increase. The dendrite-like primary α-Al appears at the same time. With the increase of stirring rate of rotating magnetic field, the change way of eutectic Si shape is coarse needle→tiny needle→coarse needle; the rotating magnetic field can change the nonuniform distribution of Bi induced by Bi local decentralization. With the increase of stirring rate of rotating magnetic field, the change way of Bi shape in upper part microstructures of the alloy is large bulk→short rodlike→big globular→small globular, Bi local decentralization is changed into uniform distribution; In addition, exerting a rotating magnetic field in the hypereutectic Al-20%Si alloy can increase wear-resisting property of the alloy.
Numerical Simulation of Concentration Field for Be/00Cr17Ni14Mo2 Stainless Steel by Diffusion Bonding
Authors: Li Hui , Wang Xuan , Zhu Yong , Zhang Peng Cheng
Published: August 2015

In order to provide the best technic parameter for hot pressing, the distributions of Fe and Be near the Be and 00Cr17Ni14Mo2 stainless steel (Be/SS) diffusion bonding interface under different technic parameter were simulated by the finite element method and measured by means of scanning auger microspectroy (AES). The simulated results were compared with experimental value, The distributions of Fe and Be near the Be/SS diffusion bonding interface and the relationships between the width of diffusion layer, the heating temperature, the holding time and the pressure were also discussed. The results indicate that under the condition of heating temperature 1323K and 1023K with diffusion pressure 60MPa and holding time 7200s, respectively, the simulated distributions of Fe and Be near the Be/SS diffusion bonding interface fit with the experimence values, and the width of diffusion layer at 1323K is about 2.5 times the one at 1023K. Under the condition of heating temperature 1023K with holding time 7200s, the width of diffusion layer measured at 30MPa, 40MPa, 50MPa and 60MPa is fit well with the simulated results and the relationship between the width of diffusion layer (x/μm) and the diffusion pressure (p/MPa) follows the eqution 0fx=-1.5×10-2p2+2.8275p-0.1575. Under the condition of heating temperature 1023K with diffusion pressure 60MPa, the simulation curve between the width of diffusion layer (x/μm) and the holding time (t/s) follows the eqution 0fx=10t3-60.571t2+135.64t+0.2143.
Fluidity of Plastic Blends with a Recycled Filler
Authors: Navratil Jan , Manas Miroslav , Stanek Michal , Manas David , Bednarik Martin , Mizera Ales
Published: August 2015

This research paper deals with an investigation of the fluidity of plastic blends with a recycled filler. Five different blends with three filler concentrations were prepared. As a fillers were radiation crosslinked plastics used. Fluidity was determined by the spiral test where a cavity with the Archimedes spiral is used and a length of the resulting spiral is evaluated and compared. Results show that the more filler is used the worse fluidity there is; however lower concentrations have fluidity almost identical to the non-filled material and the difference is almost negligible. At higher concentrations is the difference more significant and thus it has to be taken into account. Particle size of the filler should be also taken into a consideration but its influence greatly depends on the matrix.
Improvement of PA6 Mechanical Properties by Radiation Cross-Linking
Authors: Kratky Petr , Manas David , Manas Miroslav , Stanek Michal , Ovsik Martin , Skrobak Adam , Reznicek Martin
Published: August 2015

Influence of mechanical properties of the hard surface layer of modified polyamide 6 is studied. Mechanical properties are acquired by nanohardness test with using the DSI method (Depth Sensing Indentation). Hard surface layers are created by radiation cross-linking technology. This technology allows polymer materials modification followed by the change of their end-use properties. The surface layer of polymer material is modified by ionizing β - radiation. When the polymer material is exposed to the β radiation, it is possible to observe changes of the surface layer at applied load. Radiation cross-linking usually improves strength, reduces creep, contributes to chemical resistance improvement, and in many cases improves tribological properties.
Micro-Indentation Test of Cross-Linking Polyethylene
Authors: Ovsik Martin , Manas David , Manas Miroslav , Stanek Michal , Reznicek Martin
Published: August 2015

Radiation crosslinking of linear polyethylene (LLDPE) is a well-recognized modification of improving basic material characteristics. This research paper deals with the utilization of electron beam irradiated LLDPE on the micro-indentation test. The effect of the irradiation on mechanical behavior of the tested polyethylene was investigated. The results indicate that the mechanical behavior, highly depends on the intensity of irradiation. Toughness and hardness grew with increasing dose of the irradiation LLDPE. Indentation modulus increased from 0.25 to 0.28 GPa and indentation hardness increased from 21.89 to 26.25 MPa. These results indicate advantage crosslinking of the improved mechanical properties.
Thermo-Mechanical Properties and Tensile Behaviour of Modified HDPE by Beta Rays after Temperature Load at 220 °C
Authors: Mizera Ales , Manas Miroslav , Manas David , Stanek Michal , Navratil Jan , Bednarik Martin
Published: August 2015

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers, especially thermo-mechanical properties. The tensile behaviour of modified HDPE samples by radiation cross-linking was measured at the ambient temperature and after temperature load at 220 °C. The tested samples showed significant changes of thermo-mechanical properties and tensile behaviour after 220 °C. From this point of view, new applications could also be seen in areas with service temperatures higher than their former melting point.
Research on Law and Mechanism of Hydrogen Induced Softening in Ti6Al4V Alloy in the Temperature Range 400 °C to 1010 °C
Authors: Huang Shu Hui , Zong Ying Ying , Shan De Bin
Published: August 2015

The law and mechanism of hydrogen induced softening in Ti6Al4V alloy in the temperature range 400 °C to 1010 °C are researched by lots of isothermal hot compression experiment in this paper. The relationship between σh (the true stress when the test is compressed to half of its original height) and CH (hydrogen content) is investigated to describe the law. The results show that, Between 400 °C and 450 °C, the plasticity increases at first, and then decreases and the strength is almost changeless with the CH rising. Between 480 °C and 950 °C, the strength decreases at first, and then increases with the CH rising. In α+β phase region, the strength decreases with the CH rising. In β phase region, the strength increases with the CH rising. Hydrogenation induced α phase high temperature softening and hydrogenation promoting α→β phase transition are the main reasons for hydrogen induced titanium alloy softening. Hydrogenation induced β phase solution strengthening is the reason for hydrogen induced titanium alloy strengthening. And the relationship between furnace temperature and vacuum is investigated during dehydrogenation heat treatment.
Experimental Studies of Submicron Polycrystalline Diamond without Binder under High Pressure and Temperature
Authors: Yang Xing Hui , Kou Zi Li , He Duan Wei , Wang Yong Kun , Duan Wen Rui , Chen Hong Yang
Published: August 2015

This paper aims to study the sintering process and mechanical properties of submicron polycrystalline diamond (SMPD) without any secondary phases and binder materials under pressure of 7-8 GPa and 1400 °C-1800 °C, using the bi-layer assembly and the conventional assembly methods. The as prepared samples were characterized by X-ray diffraction, scanning electron microscope, and Vickers indenter hardness tests. Well sintered specimen was obtained under the condition of 8 GPa and 1600 °C using the bi-layer assembly method, and an indentation test demonstrated a Vickers hardness of 52 GPa. The graphitization of diamond was found to be an important factor determining the hardness of samples sintered using the bi-layer assembly.
Research of Cold Extrusion Process for the 2A12 Duralumin Pistons
Authors: Teng Hong Chun , Teng Bing Yan , Chen Xian Bing
Published: August 2015

The existing process of 2A12 aluminium alloy piston is cutting completed by hot- drawing pole , as a material utilization rate less than 40%. In order to improve material utilization, cold-extrusion process is the reasonable choice, but only if solve the annealing before cold-extrusion, surface lubricated, the Parameter optimization of cold-extrusion and quenching process after extrusion. This research uses the DEFORM finite element analysis and a good effect in practical application is obtained to enhance the rate of more than 80% material utilization, scrap rate is less than 0.5%.
Impact on the Reduction Process of Carbon Containing Pellets with Biomass Replacing Traditional Reducing Agent
Authors: Yuan Peng , Han Hong Liang , Duan Dong Ping
Published: August 2015

Considering the rotary hearth furnaces (RHF) direct reduction process, using bamboo char, charcoal and straw fiber as reducing agents added into the carbon containing pellets, the experimental study on the impact of reduction effect has been conducted from metallization rate, compressive strength and volumetric shrinkage. Test results showed that biomass reducing agents can replace traditional reducing agents used in the RHF direct reduction process. Compared with traditional reducing agents, biomass has less of effect on metallization rate, but different biomass reducing agents have large impact on strength and volumetric shrinkage of pellets. The compressive strength of pellet with straw fiber is relatively higher, and the compressive strength of pellets with charcoal or bamboo charcoal is low, for reaching the production requirement, which will be improved at higher temperature (1300°C). Using bamboo charcoal as reducing agent will lead to the swell of pellets in the beginning stage, and this situation will make the volumetric shrinkage at high temperature lower, finally, all of these will affect the strength of pellets and the heat-transfer between different material layers, thus it should be used accompanying with other reducing agent.
Features and Application of Electron Beam Welding Technology
Authors: Li Ming Feng , Zhu Zheng Hong
Published: August 2015

Electron beam welding technology is a mature special welding technology. The advantage of electron beam welding like these: high power density, high ratio of depth-to-width, high-quality welds. Electron beam welding equipment has been independently developed by tracking and bringing in. Electron beam welding technology has a wide range of applications in the aerospace, automotive, medical and other branches of industry, the field of applications is also expanding with the improved welding equipment. According to the demand of research and market, Electron beam welding technology will move toward the direction of universal, integrated, information-oriented in the future.
Influence of Particle Size of Wheat Powder on Roller Wear Properties
Authors: Jiang Liang Peng , Zhang Ke Ping , Ma Jun Min
Published: August 2015

Wheat milling process involves multiple grinding procedures, the wheat powder particles size in different grinding procedure are difference. In order to study the influence of particle size of wheat powder on roller wear performance in different grinding procedure, abrasion experiments were carried out by MLS-225 three-body abrasive wear tester, while different sizes were chosen as abrasive, alloy white iron which frequently used as roller metal materials was chosen as wear sample, wear weight loss and surface microstructure were chosen as the main evaluation indicators. The results showed that the weight loss of samples were showed a linear relationship with wheat the size of wheat powder. The main wear behavior was mainly mechanical polishing while particle sizes was smaller one. For the larger size, wear was made by multiple plastic deformation and low cycle fatigue wear mechanism.
Synthesis of Li2Fe0.5Mn0.5SiO4/C as Cathode Material for Lithium-Ion Batteries Using Amorphous Li2SiO3
Authors: Novikov Pavel , Silin Alexey , Wang Qing Sheng , Popovich Anatoliy
Published: August 2015

A phase-pure cathode material (Li2Fe0.5Mn0.5SiO4/C) was successfully prepared by a solid-state reaction. Initially, components used amorphous Li2SiO3obtained from a liquid phase by solidification, FeC2O4*2H2O, MnC2O4*2H2O and glucose as a carbon source. The structure of the prepared cathode material was investigated by X-ray diffraction (XRD), the content of Fe, Mn, Si by Energy-dispersive X-ray spectroscopy (EDX) method, Li content by atomic absorption spectroscopy (AAS), the particle size and morphology by scanning electron microscopy (SEM). XRD data show that the sample on the basis of orthorhombic unit cell can be attributed to Pmn21space group. An analysis of SEM images showed average particles size of about 250 nm. Other results obtained (EDX, AAS) correspond approximately to the theoretical data. Electrochemical performance of the cathode material was gained from cycling between 1.5-4.8V. Discharge capacity after the first cycle reached 220 mAh/g.
Determination of Gold in Gold Jewelry Alloys by a Synthesis Method
Authors: Li Hui , Shi Shao Jun , Wang Xuan , Zhu Yong , Yu Ning , Wang You Jian
Published: August 2015

Nondestructive determination of Au in gold ornaments mainly takes density method and X ray fluorescence spectrometer with energy dispersion (EDXRF), which exists disadvantages. This paper based on the principle of crystallography, deduced the mathematical relationship between the crystallographic parameters, the density and the impurities content in gold jewelry alloys, then introduced the results by density testing and determination of Ag and Cu by EDXRF into the mathematical relationship, and obtained the gold weight percent in gold jewelry alloys. The results show that obtained the gold weight percent and determination of Au by fire assay are almost consistent, which the error is less than 0.12 %, so establishes a synthesis method of determination of Au by EDXRF and density testing, solves the disadvantages which EDXRF only detects on gold jewelry surface and small area, and density testing cannot detect gold jewelry alloy and demands that jewelry shape is simple, and provides an effective synthesis way for determination of Au in gold jewelry alloys.
The Influence of Material Properties on the Hydrodynamic Performance of Propeller
Authors: Sun Shuai , Chang Xin , Chen Guang Jie , Zhi Yu Chang
Published: August 2015

Fluid-solid coupling numerical method of propellers is applied to make numerical calculations of propellers made of different materials without considering the material anisotropic. Comparative analysis of hydrodynamic performance and wake flow field of the propellers are carried on under typical working conditions. The influence of the key parameters of material on the efficiency of marine propellers is analyzed. The results show that the material with greater elasticity makes the magnitude of speed increase,especiously the axial velocity. On the other hand, compared with the strong rigidity material propeller, the small rigidity material propeller increases a little in the highest value of propeller efficiency curve.
Analysis on Influencing Factors of Bus Bar Contact Resistance
Authors: Liu Shun Xin , Huang Wen Li , Wen Zhen Hua
Published: August 2015

Contact resistance is one of the key parameters of main bus bar. The bus performance is decided by the value of Contact resistance. By test of the typical rectangular copper bus-bar, it is analyzed that the effects of force on DC contact resistance. The results show that metal surface contact resistance decreases with the increment of pressure. The resistance is mental nature property, which is determined by material’s performance. At the same time the effect of contact distance is studied in detail.
The Study on Porous Media Phase Change Coupling Heat Transfer Model in Enclosed Metal Cavity
Authors: Wu Run Hui , Liu Jia Qi , Liu Xin , Ren Ai Min , Zhang Sheng Jun , Meng Gang
Published: August 2015

This thesis is aimed to the external instantaneous high energy heat source, according to enclosed metal cavity, porous medium in the cavity, porous media can by phase change heat transfer characteristic of variegated medium coupling state target’s special requirements in the field of aerospace, it is innovatively to put forward a kind of applicable to simulate sealed coupling target, under the condition of instant high energy heat source excitation, By heat source-metal cavity-porous medium—porous medium’s phase-changeable phase change process heat-transfer characteristic numerical calculation model-creation approach, in use of the metal cavity, in the porous medium incompressible flow phase transition of working medium’s heat energy conservation, momentum conservation and mass conservation principle, it is to establish analysis model of coupled heat transfer characteristics of multiple parts, in order to acquire the full target area of airtight coupling state targets, temperature field, pressure field, velocity field and phase change of phase transition of working medium characteristics change with time and space change numerical value to analog result. The study results points out: when the incentive heat source keep constant, the change rule of full target area temperature, pressure flow rate and phase change characteristic parameters is in conformity with theory of heat transfer medium. The heat transfer model can be popularized and applied to the optimization design of incentive heat source, and comprehensive performance optimization of enclosed coupling state objects.
Boundary Element Analysis for Piezoelectric Cracks by an Interaction Integral
Authors: Liu He Guo , Lei Jun , Sun Peng Bo , Yang Qing Sheng
Published: August 2015

In this paper, an interaction integral is applied to evaluate the crack-tip field intensity factors for piezoelectric cracks by using BEM. Based on this, the fracture parameters for different crack configurations and loading conditions are analyzed in details for both the center crack and edge crack problem. According to the present results, the path-independent behavior of the interaction integral is verified. The comparison of the I-integral results with those by the J-integral and the displacement interpolating methods shows a good agreement.
Numerical Analysis on Decay Heat Power of Weapon-Grade Plutonium
Authors: Wang Yu Ling , Yu W.L. , Xiao X.Y. , Gao Y.L.
Published: August 2015

In order to exactly master effect of plutonium material’s heat power on safety and reliability of nuclear weapon, weapon-grade plutonium(WgPu) was regarded as research object in this paper. According to its component, decay heat power of WgPu per kilogram was calculated through dynamic decay cascade and decay law of plutonium. The maximum decay heat power of WgPu is 2.6158 watt per kilogram at seventy years.
New Materials Applied for the Stationary Phases in View of the Optimized HPLC and UHPLC Column Classification System Used in the Pharmaceutical Analysis
Authors: Plenis Alina , Bączek Tomasz , Szulfer Jarosław , Markuszewski Michał
Published: August 2015

Pharmacopoeial monographs define usually requirements for the use of the particular chromatographic packing materials in a very general way. Even if a selection of particular chromatographic column packed with the defined material is suggested, it appears often that column is currently not present in the laboratory, or is no longer commercially available. With respect to those facts, there are needs to replace the given column material for another one, however with the similar physicochemical characteristics. This can be achieved by using one of the classification systems of columns’ material (e.g., the procedure developed by the researchers at the Katholieke Universiteit Leuven – and therefore called tentatively by us as KUL procedure).In the first stage of the work, it has been proven that the results obtained by KUL procedure can be related to results obtained during chemometrics verification of the suitability of selected stationary phases’ material used in the individual columns for purity test of alfuzosin as pharmaceutical substance and their impurities and related compounds. The next step was to adapt KUL procedure to allow the classification of modern and new UHPLC and Core-Shell (CS) columns’ material characterized by the novel physicochemical properties. Together, properties of 61 columns packed with variable materials have been characterized. The last step comprised the data collection to examine the possibilities to use UHPLC and CS columns materials as equivalent ones to the classical HPLC columns’ materials in view of the method transfer for the previously mentioned assay for alfuzosin.
Preparation of CMC-PVA/PAN-FePc(COOH)8/CS-PVA Bipolar Membrane and its Application in Electro-Oxidized Synthesis of Dialdehydle Starch
Authors: Li Zhong Gui , Zhou Ting Jin , Chen Ri Yao , Chen Xiao , Zheng Xi , Chen Zhen
Published: August 2015

The polyacrylonitrile (PAN)-iron octocarboxyphthalocyanine (FePc(COOH)8) nanofibers were prepared using electrospinning technique and introduced into the interlayer of a carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA)/chitosan (CS)-polyvinyl alcohol bipolar membrane (BPM), which was characterized using SEM, contact angle measurement, current-voltage characteristics, AC impedance spectroscopy and so on. The experimental results showed that after modification by PAN-FePc(COOH)8 nanofibers, the membrane impedance of the BPM and its cell voltage were decreased. That indicated that the water splitting efficiency in the interlayer of the BPM was increased. Then the prepared CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM was used in the electro-oxidized preparation of dialdehydle starch (DAS). The experimental results indicated that a current density of 20mA·cm-2 was suitable to obtain high current efficiency. When the electrolysis time was 3h at a current density of 20 mA·cm-2 , the current efficiency of the CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM-equipped cell was as high as 67%.
Mechanical Properties and Fracture Analysis of a Plant Oil Storage Tank Accident
Authors: Fang Shan Shan , Zhang Li Jing , Tao Gang
Published: August 2015

The collapse mechanism of plant oil storage tank was discussed in the paper. Observation made on the site indicated that No. 804 tank collapsed with disintegration. The incomplete penetration area was found by weld macro analysis. Stress intensity factor of crack in the tank which is calculated using the classical theory showed that the main reason for the accident was not the incomplete penetration weld. The hexane vapor explosion is presumably the dominant factor leading to the accident by calculation and analysis. The count measures are also proposed to prevent the similar accidents.
Spall Strength of Steel Fiber Reinforced Concretes
Authors: Zhang Lei , Wu Biao , Zhou Ying
Published: August 2015

The spall fracture of steel fiber reinforced concretes (SFRC) is investigated with the strain wave profiles in buffer bar behind the specimen bar in a large size Hopkinson pressure bar equipment. The experimental results indicate that the spall strength of SFRC is related to the steel fiber volume ratio, the compressive strength of concretes and the load rate (impact velocity). The spall strength of SFRC empirical formula shows the relationship between these factors. The conclusion that the steel fiber has the effect to improve the ability to prevent spall fracture is of real importance in the correlative numerical simulation and protective engineering design.
Seismic Performance of Natural Fibre Reinforced Polymer-Concrete Bridge Piers
Authors: Chen Jia Xin , Chouw Nawawi
Published: August 2015

This paper addresses the usage of new construction materials made of natural fibre reinforced polymer and concrete composite for future earthquake-resistant structures. The structure considered is a simple circular bridge pier. To evaluate the seismic performance of the structure shake table experiments were performed. To reveal the consequence of the magnitude of the ground excitation for the structure the effect of a gradual increase of the peak ground displacement is investigated. The results show that although external damage to the structure cannot be observed the bond between polymer and concrete is a significant factor that determines the performance of the structure.
The Research on Bond Property of Rubber Concrete
Authors: Dong Lan Qi , Liang Chao Feng , Wang Xiao Gang , Zhou Zecheng Long , Chen Yan Li
Published: August 2015

In order to realize the recycle of waste tires, rubber concrete can be utilized in road engineering. The bond property of interface between rubber concrete and matrix ordinary concrete is one of the key factors. This paper studied the interfacial bond property by splitting tensile strength test and shear strength test and considered several influence factors, such as rubber volume fraction, rubber particle size, interfacial roughness and curing time of matrix concrete. The results show that the shear strength decreases with the increase of rubber content, longer curing time of matrix concrete, and the larger size of rubber particle. The splitting tensile strength also deceases with the longer curing time of matrix concrete or smaller interfacial roughness. However, no regular relationship is found between the splitting tensile strength and the size of rubber particle or rubber volume content.
Seismic Behavior of Steel Plate Shear Walls-Steel Frame
Authors: Shao Feng Ru , Shao Yong Song
Published: August 2015

A model with the ratio of 1:4 of a six layers’ semi-rigid steel frame-steel plate shear wallssystem has been tested on the shaking table.The strain variation of the steel plate shear wallsand the system’s seismic behaviors to different kinds of seismic waves from four different siteclassification and with different peakaccelerationwere analyzed to provide theoretical and experimental evidence to the real projects.
Synthesis of and Characterization of Polyhedron of Mn2O3 Nanoparticles Using Spent Zn-Mn Batteries
Authors: Xu Fang , Yin Jun Xia , Yang Ming
Published: August 2015

Polyhedron composed of Mn2O3nanoparticles with an average diameter of 0.5-1.0 μm have been prepared using spent Zn-Mn batteries. The product was characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of polyhedron composed of Mn2O3 for 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was investigated. The adsorbent showed high efficiency for the removal of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol in water. The equilibrium of adsorption was achieved within 40 min. The isotherm adsorption data obeyed the Langmuir model, with a maximum adsorption capacity of 62 mg g-1.