bluuebunny/crossref_metadata_2025 huggingface dataset:
Organic EL Devices with Bis-Diphenylquinoxaline as ET Material
Authors: Li Ting Xi , Gao Su Su , Sui Peng , Kong Na , Wu Shasha , Li Shan Ting
Published: May 2011

A new compound, 2,3,2',3'-Tetraphenyl-[6,6']-biquinoxalinyl was synthesized. Its structure was determined by mass spectrometry and elemental analysis. Organic electroluminescent devices using this compound as electron-transporting layer were fabricated and electroluminescent properties were studied. It was demonstrated that this compound has excellent electronic transmission performance in organic light-emitting diodes (OLED).
Experimental Research on the Mechanical Properties of Compacted Cement Soil in Collapsible Loess Area and Engineering Application
Authors: Yu Ying Xia , Jiao Yu Feng , Liang Bin , Zhang Wei
Published: May 2011

Based on the compaction test and unconfined compression test of cement soil, the optimum water content is ascertained. The relationship is studied about cement content, curing time and unconfined compression strengths, ultimate strain of compacted cement soil in this paper. The results indicate that the unconfined compression strengths increase in linear with the increase of curing time and cement content on the whole, and the ultimate strains decrease with the increase of cement content and curing time. The results provide theoretical basis for rational construction mixture ratio and parameter which have been successfully used to a project and achieved good economic benefit.
Permeability of Concrete Containing Air-Entraining and Mineral Admixtures
Authors: Huang Wei Rong , Yang De Bin , Zhou Jian Ting , Li Li , Zhang Wei Na
Published: May 2011

In this paper, the performance of concrete is studied through different water-cement ratio, different air-content, different mineral admixtures, different admixture contents, examined the mechanical properties of concrete, electric flux and chloride ion penetration depth of different mix concrete. The results show that, decreasing w/c ratio, proper air content, adding mineral admixtures can improve the resistance of chloride-permeation. Within some contents, the chloride-permeation resistance using silicides is better than that of fly-ash or slag. On this basis, the proper scheme of mix ratio used in saline area is recommended: the air-content is 3%～5%, the content of fly-ash or slag is 20%～30%, the content of silicides is 6%～8%, and double mixed with silicides.
Optimal Design of DFRCC Subjected to Fatigue Loading
Authors: Chun Pang Jo , Matsumoto Takashi
Published: May 2011

This paper describes the optimal design of ductile fiber reinforced cementitious composite (DFRCC) under fatigue loading. First of all, fatigue tensile experiments of the DFRCC under constant strain amplitude were conducted, and the degradation of bridging stress was measured. The test results were employed to verify the micromechanics-based theoretical model developed in this research. The model accounts for the loss of fatigue ruptured fibers of which fatigue rupture is based on S-N relationships. According to the parametric study from the theoretical model, we found that the optimal choice of design variables, such as fiber length, is varied according to the maximum strain level and the number of cyclic loading. Therefore, it is required to design DFRCC optimally under given loading conditions to make the most of its excellent material properties and the developed model enables such a design.
Mechnical Property Study of the Slab Filled with DEPP
Authors: Zhang Hao , Xu Qi Keng , Zhang Xian Bing , Wang Lu Min , Zhang Da Ying
Published: May 2011

The slab filled with Disused Expanded Polystyrene Plastic(DEPP) has many advantages. It is able to save concretes, decrease self weight and improve its functions of heat preservation, heat insulation and sound insulation. It is possible to transform DEPP into treasures and reduce environmental pollutions. So it can be widely used. In this paper, the mechanical properties of the slab filled with DEPP is explored through the experiments. Results show that the structure of the slab filled with DEPP is reasonable and satifies the correlative codes. References to the design of the slab filled with DEPP is also offered in this paper.
Influence of the Fly-Ash Content of Concrete at Low Water-Binder Ratio on Hydration Degree of Binders and Cement
Authors: Xu Li Wei , Zheng Jian Lan
Published: May 2011

The hydration degree of binders and cement is investigated by measuring the adiabatic- temperature rise of concrete at low water-binder ratio with different fly-ash content. The results denote that, with a constant water-binder ratio, both of the hydration degree of binders and that of cement decrease with the increasing fly-ash content in the early stage. In a later stage, however, the hydration degree of cement increases with the increasing fly-ash content and the hydration degree of binders peaks when the fly-ash content is 35%. Fly ash is one of the mineral admixture of which high-performance concrete is made up. It brings down the rise of concrete temperature significantly and helps solve the problems of shrinkage and crack of concrete structure. Because the hydration mechanism in common concrete is different from that in concrete with low water-binder ratio, and the hydration environment is different between concrete and cement pastes, to determine the adiabatic-temperature rise of concrete directly conforms to the actual situation. The adiabatic-temperature rise, adiabatic-temperature-rise rate, hydration degree of both binders and cement are investigated by measuring adiabatic-temperature rise of concrete with different fly-ash content.
Preparation and Performance Research on Phenolic Insulation Foam Used Low-Temperature Foaming Technology
Authors: Zhuang Xiao Wei , Li Shou Hai , Ma Yu Feng , Zhang Wei , Xu Yu Zhi , Wang Chun Peng , Chu Fu Xiang
Published: May 2011

The phenolic(PF) foams were prepared used low-temperature foaming and curing method. The optimum low-temperature foaming processing technology conditions and material proportioning were described below. The curing temperature was 40 °C, the amount of foaming agent iso-pentane was 8-10wt.%, tween-80 dosage was 6-7wt.%, the amount of composite curing agent was 15-18wt.%.The effects of low-temperature foaming on mechanical properties, heat insulation, fire-retardant, foam hole form and micro-structure were discussed. 40°C and 70°C curing PF foam performance comparison results showed that low-temperature curing technology slightly affect the fire-retardant properties of PF foam. And excellent overall performance PF foam were prepared with 40°C foaming technology, the foam hole morphology structure, toughness and strength of PF foam were better. In addition, the low-temperature curing PF foam had more even foam hole distribution, more regular foam hole structure, more clean foam hole arrangement.
Influence of Nano-SiO2 and Nano-CaCO3 on the Mechanical Properties of Concrete with Different Strength Grades
Authors: Huang Miao Zhou , Meng Tao , Qian Xiao Qian , Zhang Jin Jian
Published: May 2011

The flow ability, mechanical properties and microstructure of concrete with different strength grades affected by nano-SiO2and nano-CaCO3was studied. The experiment results showed that the strength of concrete at early age was increased by adding the nano-materials if the strength grade of concrete was not high. But the strength at the age of 28 days was not affected a lot by adding these nano-materials. On the other hand, it was not useful to the strength if the strength grade of concrete was high.
Experiment Study on the Durability of Dry-Mixing Self-Compacting Concrete
Authors: Zong Lan , Zhang Shi Ping , Liang Pei Xin
Published: May 2011

Durability of dry-mixing self-compacting concrete was evaluated through carbonation testing, freeze-thaw testing and chloride ions diffusion testing. The results indicate that carbonation resistance, frost resistance and chloride ions diffusion of durability of dry-mixing self-compacting concrete are excellent, compared with normally vibrated concrete (NVC). Durability of dry-mixing self-compacting concrete shows a better pore structure. Furthermore, the more the content of coarse aggregates is, the poorer the pore structure becomes.
Study on the Corrosion Resistance of Polymer-Modified Reactive Powder Concrete
Authors: Lin Dong , Yuan Yu Fei , Wen Zi Yun
Published: May 2011

In ordinary processing condition, using small amount (2%) of polymer to modify reactive powder concrete (RPC), the performance of modified and unmodified RPC was studied for their corrosion resistance with water-dip-in, acid-dip-in and sulphate solution-dip-in tests and was verified by the strength loss rate. The results show that not only the corrosion resistance but also the strength, especially the flexural strength, has been improved obviously after the polymer modification. The mechanism has been studied with SEM and EDS analysis.
Influence of Silane Treatment on the Freeze-Thaw Resistance of Concrete
Authors: Gao Xiao Jian , Deng Hong Wei , Yang Ying Zi
Published: May 2011

The influences of silane impregnation on water adsorption, bonding force between ice and concrete surface and resistance to freeze-thaw of concretes were studied. Two strength grades (C30 and C50) and the air entrainment were considered for concrete preparation. The results show that surface impregnation with silane reduces the final water adsorption of concrete by more than 90% when compared with the untreated specimen. The silane treatment significantly decreases the bonding force between ice and concrete surface. The resistance to freeze-thaw of both new and old concretes can be improved by the silane treatment. Therefore, the surface treatment with silane is suggested as an effective method to improve the durability of concrete structures in cold regions.
New Type Spherical Pores Al Foam and its Properties
Authors: Wang Zhan Guang , Cai Ping , Wang Zhen Wu
Published: May 2011

Based on compression curves of spherical pores Al foam measured, compressive yield strength, the densification starting pointand energy absorption had been investigated. The compressive stress-strain curve of spherical pores Al foam consists of three distinct regions, i.e., the linear elasticity region, yield platform stage and the densification region. The way to determine the densification starting pointεDof high density metal foam has been presented. Spherical pores Al foam is a cellular metal material of high plastic performance, so energy absorption capability of it is bigger than that of spherical pores Al alloy foam. Compressive yield stress was in good agreement with Gibson-Ashby model’s expectation．
Investigation on Application Performances of Chrome-Free MgO-Al2O3-ZrO2 Bricks for Sintering Zone in Cement Kiln
Authors: Li Yue , Li Yong , Xia Wen Bin , Zhou Wei , Ma Shu Long , Wang Dong
Published: May 2011

Four groups of specimens were made from Magnesia and alumina-zirconia synthetic materials, the content of alumina-zirconia synthetic materials was 5%, 10%, 15% and 20% respectively. While one group of reference specimen was made from magnesia and magnesia-alumina spinel at the same conditions for comparing. The Ligno-sulfite was used as binder. The raw materials were mixed homogeneously and then were molded to 5 groups of specimens. After being dried at the temperature 100°C holding 24 hours, the bricks were sintered at the temperature 1530°C 10h, and then the physical performances of the specimens were tested. Phase composition and microstructure of the specimens were also analyzed. The result shows that the performances of the MgO- Al2O3-ZrO2 specimens are better than that of MgO-Al2O3 specimen. The specimen which contains 10% alumina-zirconia synthetic materials has the best comprehensive performance. The thermal shock resistance and erosion resistance of the MgO-Al2O3-ZrO2 specimens are better than the MgO-Al2O3 specimen. It proves that MgO-Al2O3-ZrO2 bricks are potential good material for sintering zone.
Study on Test about the Impermeability of Magnetic Water Concrete
Authors: Wang Yi Xin , Wang Xuan , Wang You Kai
Published: May 2011

The compactness and water impermeability of the concrete mixed with magnetized water in different degrees are studied in the thesis. According to the principle of cross-test, 21 samples with the intensity levels C20, C25 and C30 are chosen in the impermeability test. The test indicates the difference of impermeability between magnetized water concrete and ordinary water concrete at the condition of same strength to study the special law influenced by the flow speed of water and the magnetic field strength. The best magnetic field strength and the best water flow speed have been obtained among the range of test parameters.
Experimental and Economic Analysis of Airport Crumb Rubber Concrete (CRC) Pavement
Authors: Li Yan Ru , Zhu Han , Liu Chun Sheng
Published: May 2011

The feasibility of using crumb rubber concrete (CRC) in airport pavement is discussed by analyzing the capability of crumb rubber concrete. The bending property of CRC is studied by four point loading test of small-sized rubber concrete beams. Comparing with cement concrete (CC) pavement, the board thickness of CRC pavement is analyzed. The conclusions are reached that appropriate mixing of crumb rubber could satisfy strength demand and improve durability of airport pavement, and the thickness of CRC pavement is 93 percent of that of CC pavement. As a result, airport CRC pavement has longer service life and perfect cost performance.
Experimental Research about Weathering Resistance and Surface Deterioration of Two Kinds of Stone Cultural Relics
Authors: Wang Yang , Xia Yong , Zhang Jin Song , Li Hong Song , Dai Shi Bing , Tang Zhong
Published: May 2011

Doing experiment about weathering of two kinds of stone cultural relics, through measuring some technology index, comparing weathering resistance and surface deterioration of these stone cultural relics, discussing the reason of arising weathering and surface deterioration from internal and external factors, so these may offer some contribution to protect this kind of stone cultural relics.
Effect of Clay Dosage on Mechanical Properties of Plastic Concrete
Authors: Guan Qiao Yan , Zhang Peng
Published: May 2011

A designed experimental study has been conducted to investigate the effect of clay dosage on mechanical properties of plastic concrete. The mechanical properties include compressive strength, splitting tensile strength, shear strength and elastic modulus. On the basis of the experimental results of the specimens of eight sets of mix proportions, the mechanism of action of clay on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of clay dosage. However, the internal friction angle of the shear specimens is increasing gradually with the increase of clay dosage. Further, the clay appears can improve the ductility of plastic concrete and this can help plastic concrete to bear larger deformation before failure.
Study on the Ultra High Performance Concrete Containing Limestone Powder
Authors: Liu Shu Hua , Gao Zhi Yang , Rao Mei Juan
Published: May 2011

A new kind of ultra high performance concrete containing limestone powder was studied in this paper. The results show that the compressive strength of the ultra high performance concrete containing limestone powder is higher than 120MPa; the hydration activity and the accelerating effect of limestone powder are obvious under the condition of high temperature. The limestone powder hydrated and formed calcium monocaboaluminate hydrates. The cost would be reduced when adding certain amount of limestone powder when confect ultra high performance concrete. It is economical and feasible.
Mechanical Properties Analysis of the Microstructure of Rubber Modified Concrete
Authors: Kou Lei , Pan Fu Ting , Wang Cheng Yu
Published: May 2011

Based on the research results of the microstructure of concrete, and considering the characteristics of rubber modified concrete, this paper proposed an analysis model of the microstructure of rubber modified concrete. According to the analysis model, comparing the influence of incorporation of rubber particles, no incorporation of rubber particles on the mechanical properties of concrete, the analysis result was in good accord with the experimental results, which confirmed the correctness of analysis model, then the mechanical properties of rubber modified concrete were analyzed.
Utilization of Desulfuration Residues in Non-Autoclaved Aerated Concrete
Authors: Li Fang Xian , Chen You Zhi , Yu Qi Jun , Wei Jiang Xiong
Published: May 2011

Desulfuration residues were used as aggregate to produce Non-autoclaved aerated concrete. The effects of water-hinder ratio, casting temperature on the gas forming behavior, and those of desulfuration residue content on the compressive strength and bulk density of aerated concrete were investigated. The types of the hydration products and the microstructure of Non-autoclaved aerated concrete with desulfuration residue were investigated by means of X-ray diffraction and scanning electron microscope. Results show that the optimum replacement amount was determined as 50% and at this rate the compressive strength, bulk density of Non-autoclaved aerated concrete were measured as 2.83 MPa and 543 kg/m3. The hydration products of Non-autoclaved aerated concrete with desulfuration residue are C2SH (A) and C2SH (B) along with ettringite and hydrogarnet phases.
The Compounding and Application Mechanism of Polycarboxylate-Based Superplasticizers in the Self-Compacting Concrete
Authors: Gui Miao Miao , Fang Yun Hui , Lan Zi Dong , Yu Fei Yu , Lin Tian Xing , Jiang Zhuo Jun , Wen Qing Ru
Published: May 2011

Polycarboxylate-based superplasticizers are synthesized by radical graft copolymerization reaction, and the products are divided into ester series (PC-1) and ether series (PC-2) on the basis of different big monomers. This article studies on influence of the different composition and dosages of the synthetic superplasticizers in the self-compacting concrete (SCC). The results show that the requirements of SCC workability can be achieved through simple adjustment kinds and dosages of the synthetic superplasticizers under the given mix proportions and the raw materials. And the main mechanism of the polycarboxylate-based superplasticizers is steric hindrance effect.
Study on Carbonation and Corrosion Resistance of Reinforced Recycled Concrete
Authors: Sun Ya Li , Tian Fang , Xie Xian Song , Chen Yao Yong
Published: May 2011

By processing waste into recycled aggregate concrete, and producing recycled concrete aggregate with 50 percent of it replacing natural gravel, we make a study of different curing conditions on the carbonation of recycled concrete as well as the resistance capacity of steel corrosion. The experiment results indicate that the depth of carbonation of recycled concrete increases sharply with the standard curing period lowering. The recycled concrete steel corrosion resistance rate decreases as standard maintenance ages. The recycled concrete steel corrosion rate is much lower than the general concrete steel. The steel corrosion weight loss rate of general concrete is less than 0.3%, with no rusting of the steel. The steel corrosion weight loss rate of recycled concrete is mostly more than 0.3%, with apparent rusting.
Failure Load Prediction of Bolted Single-Lap Composite Joint Based on XFEM
Authors: Wang Zhen Qing , Zhou Song , Zhang Ji Feng , Wang Xiao Qiang
Published: May 2011

Composite materials have excellent mechanical properties and can be mechanically tailor designed, so the composite materials are widely used in civil engineering and structural system such as aerospace and shipbuilding industry. Numerous studies show that the damage of joints is main reason which results in composite structure failure. In this paper, extended finite element method (XFEM) is applied to investigate the failure load prediction of bolted single-lap composite joint. The influences of geometric parameter: edge-to-diameter (E/D) on failure load is investigated.
Synthesis and Properties of Mn-Doped Alumina Red Pigment Prepared by Low-Temperature Combustion-Calcination Process
Authors: Wang Shuang Xi , Yang Jun , Ouyang Xue Qiong , Han De Hong
Published: May 2011

Mn-doped alumina red pigment was prepared with Mn(NO3)2·6H2O and Al(NO3)3·9H2O as main raw materials by Low-temperature Combustion-Calcination process. The Mn-doped alumina red pigment was tested by XRD, SEM and CIE L*a*b* colour parameter measurement. The results showed that the reaction of Mn(NO3)2·6H2O, Al(NO3)3·9H2O and CH3COONH4with the theoretical ratio could be ignited and self-propagating at 500 °C. One kind pigment with excellent chromatic performance had been gained at the ratio about 1:40 between Mn(NO3)2·6H2O and Al(NO3)3·9H2O. The crystallite of the precursor obtained by Low-temperature Combustion synthesis (LCS) is imperfectly developed and the aggregation of particles is serious. The crystallite of the powder grows up more perfectly after calcined at 1000 °C for 4 hour with a corundum-like structure. The average particle size of the pigment is approximately 5 μm.
Research on Superplastic Zn-22Al Alloy with a Large Size to a New Seismic Damper
Authors: Kong Ling Jun , Dong Xue Hua , Chen Yan Bei , Ning Xiang Liang , Wang Jing Tao , Liu Jin Qiang
Published: May 2011

To develop a superplastic damping device, the mechanical properties and superplastic capability of Zn-22Al alloy with a large size in the rolled samples were investigated. It is indicated that the alloy with a large size has some advantage properties, such as high ductility, low yield stress and low work hardening at room temperature, which is very useful to a seismic damper.
Preparation of a New Kind of Ultra-High Performance Water Reducer and its Application Study
Authors: Duan Guo Rong , Wang Xin , Huang Guo Hong , Gong Ying
Published: May 2011

For the first time, a new kind of polycarboxylic acid high-performance water reducer, with ultra-high water reducing performance, was prepared through one-step polymerization, using new type polyether TPEG and acrylic acid as raw materials. Maximum water-reducing ratio of TPC may reach 50%. The most distinguishing characteristic of TPC was its reaction character at normal temperatures (30°C), which was of great practical significance for energy conservation and pollution reduction.
Discussion on Application Prospect of Starch-Based Adhesives on Architectural Gel Materials
Authors: Wang Yun
Published: May 2011

Starch in architecture material industry has been paid much attention for its inexpensive price, good characteristics of bonding, forming property and good biodegradability. In the paper, the research progress of starch on architectural constructional materials is concluded in five aspects of green wood adhesive, coatings binder, mortars preparation, concrete water reducing agent and ceramic production. It is suggested that the new starch-based architectural gelled material should be prepared and replaces the traditional gelled material —cement in the future for the reasons of application limited of starch and problems caused by cement producing process, and the application prospect of starch-based adhesives in related field is also proposed in the end.
Syntheses of Ethyl Cellulose Acrylate Hybrid Latex via Mini-Polymerization
Authors: Chen Ri Qing , Chu Fu Xiang , Wang Chun Peng , Bourgeat-Lami Elodie , Lansalot Muriel
Published: May 2011

Ethyl cellulose was hybridized with methyl methacrylate and butyl acrylate via mini-polymerization. The polymerization process was traced to obtain a stable reaction system. The effects of the EC content and viscosity on the monomer droplet size, the particle size and the monomer conversion were investigated. It was showed that the stability of the latex dispersion was strongly dependent of the EC content and viscosity. With investigation on ethyl cellulose series, initiator and crosslinker, the stable mini-emulsion with 10% ethyl cellulose was obtained under conditions of crosslinker and LPO as initiator.
Freeze-Thaw Model and Service Life Prediction of Hybrid Fiber Reinforced Lightweight Aggregate Concrete
Authors: Huo Jun Fang , Liu Da Peng , Shen Xiang Dong , Chu Jian Jun , Song De Tian
Published: May 2011

The effect of the frost resistance on hybrid fibers reinforced lightweight aggregate concrete is investigated. And hybrid fibers reinforced lightweight aggregate is that steel fiber and polypropylene fiber are selected to incorporate into. The results indicate that, hybrid fibers reinforced lightweight aggregate concrete can improve the frost resistance. The weight loss rate of hybrid fibers reinforced lightweight aggregate concrete is not better. The research to establish a model for service life prediction of hybrid fibers reinforced lightweight aggregate concrete on experimental results has been done.
Study on Frost Resistance Durability of Lightweight Aggregate Concrete Improved by Fiber
Authors: Huo Jun Fang , Yang Hui , Hou Yong Li , Chu Jian Jun , Li Wei Ling
Published: May 2011

Pumice, polypropylene fiber, steel fiber and fly ash were used to compound fiber reinforced lightweight aggregate concrete (LWAC). The effect of fibers on frost resistance durability of LWAC is studied, which including freezing-thawing in 5% Na2SO4 solution and in water. The test results show that the strength loss of LWAC is reduced with the increase in fiber fraction, but the impact of mass loss is not obvious by mixing fiber. LWAC freezing-thawing deterioration is even more serious in salt solution than in water. SEM photo show that polypropylene fiber has more stronger cementing bond with paste than steel fiber. the mass loss and strength loss are decreased significantly. By introduction silica fume can improve Interfacial Transition Zone（ITZ）and the frost resistance of fibers reinforcement LWAC dramatically.
Properties of Cement-Based Materials Containing Melting Incinerator Bottom Ash
Authors: Cheng An , Hsu Hui Mi , Chao Sao Jeng , Lin Wei Ting , Chen Hao Hsien , Lin Che Ting
Published: May 2011

This paper presents an experimental investigation on the effect of incinerator bottom ash (IBA) fineness and the cooled process of molten IBA on fresh mortar properties and compressive strength of hardened mortars. IBA with two finenesses, an original IBA, and a pulverizing incinerator bottom ash (PIBA) powder, with maximum particle size of 4.75 and 0.074 mm respectively were used to partially replace sand and Portland cement at 0%, 10%, 20%, 30%, and 40% by weight. The pozzolanic activity characteristics of powder were obtained from melting the above PIBA in an electric-furnace at 1450 °C for 1 h. and chilled by quenching in water (WIBA) and air (AIBA). Results indicate that incinerator bottom ash caused a reduction in compressive strength, unit weight, and flowability values when used as a replacement for sand and cement. However, IBA can be processed by melting to regain reactive pozzolanic activity, which may be used to partially replace cement.
Study on Properties of Self-Compacting Concrete with Recycled Powder
Authors: Quan Hong Zhu
Published: May 2011

To utilize the recycled powder as concrete additives, self-compaceing concerte with recycled powder, granulated blast-furnace slag and granulated limestone were tested for slump-flow, compressive strength, modulus of elasticity and drying shrinkage. Reduction in superplasticizing effect of high-range water reducer was found for concrete with recycled powder. Compressive strength of concrete with recycled powder were the same as those with granulated limestone, and lower than those with granulated blast-furnace slag. Concrete with recycled powder showed lower elastic modulus and higher drying shrinkage than those with granulated blast-furnace slag and granulated limestone. The addition of granulated blast-furnace slag together with recycled powder to self-compacting concrete improved superplasticizing effect of high-range water reducer and properties of concrete.
Exploration on Feasibility of Preparing Cement Clinker with Artificial Aggregate Concrete
Authors: Wang Jin Bang , Zhou Zong Hui , Xu Dong Yu
Published: May 2011

Combining with the utilization of waste, an new idea of using the waste to prepare high-strength artificial aggregates was put forward in this paper. The concrete was also prepared by using these aggregates. The demolished concrete could be recovered and used as cement raw meal to produce new cement clinker. In this study, the feasibility of making cement clinker with this kind of demolished concrete was studied. The concrete aggregates composed of steel slag, blast furnace slag, coal gangue and fly ash were prepared. The concrete was prepared using these aggregates with the water-cement ratio of 0.45, 0.50 and 0.55 respectively. The compressive strength of the concrete in 28 days is 52.8MPa, 46.4.2MPa and 42.6MPa, respectively, higher than that of ordinary concrete. In accordance with the ratio of cement raw meal, the cement clinker is produced by adding appropriate limestone, clay and other correction materials. After hydrated for 3 days, 7 days and 28 days, the cement paste compressive strength is 47.1 MPa, 59.8 MPa, 75.6 MPa, respectively, which reach the requirements of ordinary 42.5 Portland cement.
Preparation of Conductive Fine Flake Expanded Graphite/Polyaniline Composites
Authors: Li Yu Feng , Luo Xi , Wang Lei
Published: May 2011

Conductive fine flake expanded graphite/polyaniline composites was prepared by emulsion polymerization with sodium dodecyl benzene sulfonate(SDBS) as emulsifying agent, ammonium persulfate as initiator, hydrochloride and fine flakeexpanded graphite as dopants. Effects of hydrochloric acid, dopant, emulsifier and initiator to the conductivity has also been found through orthogonal experiment. The best condition, under which the conductivity is over 2.0S/cm, is 6% doped graphite, 6ml hydrochloric acid, 5.00g emulsifier and 3.25g initiator. It also demonstrates the improvement of the conductivity of polyaniline (PANI) via addition of graphite.
Research on Light-Duty and Energy-Saving Characteristic of Membrane Structure and its Development Prospect
Authors: Sheng Jian Rong , Zhang Tian Jiao
Published: May 2011

This paper analyses the membrane structure’s building material, structural style and its deformability, through which we pointed out that the membrane structure features light-duty and sustainable characteristic. Besides, this article describes the advantage of membrane structure in the area of environment protection and energy-saving from three points of view: acoustic, optical and thermal properties. In addition, development trends of membrane structure in the future constructions as well as the applications in China’s construction development are discussed, leading to the conclusion that the membrane structure, as a kind of light-duty architecture, has great prospects for environment protection and energy-saving applications.
Volatile Organic Compounds Emissions of Particleboards in Response to Processing Parameters
Authors: Liu Yu , Shen Jun , Zhu Xiao Dong
Published: May 2011

The purpose of this study is to reveal the concentration variations of VOC concentrations of larch particleboards with different processing parameters. The mat moisture content (MC), panel type and density were chosen as the influencing factors to investigate the VOC emissions after processing, and consequently provide basic guideline for the selection of processing parameters of particleboards to control the pollutants. 1m3 environmental chamber and portable VOC monitor were used for VOC sampling and analysis. The results showed that these factors had significant impact on VOC concentrations. The increase of MC, board panel and density had a positive effect on VOC emissions. With the MC and board density various in the ranges from 6%-14% and 0.60-0.80 g·cm-3, the TVOC concentrations increased 42.6% and 74.7% separately. The three layers particleboard had the higher concentration than the single layer particleboard.
New Light Flame-Retardant Materials of Reinforced Melamine-Urea-Formaldehyde (MUF) Foam with Wood Pulp Fiber: Preparation and Properties Evaluation
Authors: Li Shou Hai , Zhuang Xiao Wei , Ma Yu Feng , Wang Chun Peng , Chu Fu Xiang
Published: May 2011

New composite foams were prepared by using Melamine-Urea-Formaldehyde (MUF) resin and wood pulp fiber as raw materials with co-foaming method at 70°C in the opening mould. The study of the composites foam microstructure showed good adhesion between MUF matrix foam and wood pulp fiber. The flame-retardant, mechanical, anti-brittleness and insulation properties of composite foam were excellent. The results indicated that composites had superior properties enough to replace the conventional foam materials.
Dynamic Simulation of the Pile-Soil Interaction in the Vibratory Pile Driving Process
Authors: Li Xiao Peng , Duan Ze Liang , Li Tao , Wen Bang Chun
Published: May 2011

In the pile driving process, the soil dynamic performance and the dynamic contact on the interface are very complex. In order to analyze the interactions between the pile and soil, the simulation model of the pile-soil system is created by the finite element software. The numerical solution and the displacement curves of the pile are obtained based on suitable parameters of the pile-soil system and the D-P criterion. Then the amplitude and the frequency of the exciting force as well as the stiffness and the damping of the soil are changed to obtain the displacement curves of the pile. Through the comparisons between the curves, the influences on the pile driving process coming from the exciting force and other parameters are found out.
Studies of the EPR Parameters and Local Structure of Co2+ in ZnO
Authors: Kuang Min Quan , Wu Shao Yi , Song Bo Tao , Li Li Li
Published: May 2011

The EPR parameters and the local structure for Co2+ in ZnO are deduced from the perturbation formulas of these parameters for a 3d7 ion in a trigonally distorted tetrahedron. The ligand orbital and spin-orbit coupling contributions are taken into account uniformly from the cluster approach in view of the covalency of the system. The impurity V3+ is found not to locate exactly on the Zn2+ site but to experience a small displacement of 0.04 Ǻ away from the ligand triangle, along the C3 axis. The theoretical EPR parameters based upon the above impurity displacement are in good agreement with the observed values.
Physical Analysis of Structural Transformation in Ge-Incorporated a-SbxSe100-x System
Authors: Sharda Sunanda , Sharma Neha , Sharma Pankaj , Sharma Vineet
Published: May 2011

Chalcogenide glasses are suitable for far-infrared and imaging applications. In the present study, Sb10Se90-xGex (x=0, 19, 21, 23, 25, 27) system has been chosen to study structural transformations via physical parameters. Bulk samples with x = 0, 19, 21, 23, 25 and 27 have been prepared using the melt-quenching technique. A theoretical study of the ternary glass system revealed that there was a significant change in the structural environment of the system due to rigidity percolation, which took place as Se was replaced by Ge, and hence resulted in changes in other physical parameters of the system.
A Boost-Up Method of MEMS-Bulk-Micromachining towards C-MEMS Fabrication for Sensing and Manipulating Bioparticles
Authors: Malik M. Rizwan , Shi Tie Lin , Tang Zi Rong , Haseeb M.
Published: May 2011

Much of the recent ongoing advanced research into the quest for improved etching techniques has brought forth a broad concept for the fabrication of micro/nano-electromechanical systems (MEMS/NEMS) having high accuracy, precision, efficiency, compatibility and through-put of metallic- as well as carbon-composition structural phases. This in turn leads towards a thorough understanding of the sensing, trapping, separating, controlling, positioning, directing, concentrating and manipulating of micro-nano-sized particles - predominantly biological particles - in the emerging MEMS/NEMS technological field. This paper focuses its attention on the easiest means of wet-etching {100}-type silicon wafer surfaces by guiding the choice of [<100> or <010>] orientation (at 45° to the normal orientation). This anisotropic etching is performed in KOH solution. Here, consideration is not concerned to a large extent with process parameters as in anodic oxidation, an intensely doped boron etching stops and silicon wafer surface back-etching. The main concern of the present practical application route involves a passivating material (silicon dioxide, SiO2) and two masking stages (for a two-step etching process). As a example of this method, silicon cantilever beams having vertical edges are produced. It is concluded that the method presented will be helpful in the comprehensive study of resonators, pressure/temperature sensors, three-dimensional carbon micro-electrodes, actuators and accelerometers for bioparticle applications.
Low-Power Operation of Pt/Porous Si Schottky-Diode Gas-Sensor through a Reduction in its Breakdown Voltage
Authors: Khatami Saeid , Akrami Hamid , Fattah Ali
Published: May 2011

In this work gas sensors based on PtSi Schottky diode using <100> n-type porous Si were designed, fabricated, and tested. These gas sensors detect polar gases (the gases with internal dipole moments) such as CO and non-polar gases (the gases without internal dipole moments) such as CO2. The operation of these Schottky diode sensors is carried out in breakdown region and shifts in their breakdown voltage in the presence of certain gases are mapped into the concentration of those gases in the environment. Fabrication of PtSi diode based gas sensors was reported earlier elsewhere. Our main objective in this work was to significantly reduce the breakdown voltage of these sensors hence making their use more economical. Such reduction was achieved through a series of systematic changes and optimization in the pore's geometries by careful study, analysis, and changes in the experimental conditions such as temperature, acid concentration, chemistry of the etching solution, and time.
Mechanical and Functional Properties of Titanium Alloys Processed by Severe Plastic Deformation
Authors: Stolyarov Vladimir V.
Published: May 2011

Systematized literature data related to the study of mechanical and functional properties of ultrafine-grained and nanostructured metallic materials processed by deformation methods are presented. Special attention is given to the mechanical behavior of titanium materials under tension, as well as under impact and cyclic loads. The advantage of the materials under investigation over their coarse-grained analogues is shown.
Grain Refinement in Commercial Purity Titanium Sheets by Constrained Groove Pressing
Authors: Kumar G.V. Preetham , Niranjan Ganesh G. , Uday Chakkingal
Published: May 2011

Grain refinement studies in titanium have gained significant interest owing to its importance as a biomaterial. Severe plastic deformation techniques have been widely applied for grain refinement in metals and are capable of producing ultra fine and nano sized microstructures. In this study, repetitive shear deformations by constrained groove pressing have been applied to commercial purity titanium sheets of 2 mm thickness at a warm working temperature of 300oC. Microstructure studies reveal the formation of elongated grains with widths of the order of 0.5μm from an initial grain size of 40μm in the annealed condition. An increase in strength is also observed.
Thermal Stability of Fine Grains as a Function of Process Parameters in FSW Butt Joints
Authors: Cerri Emanuela
Published: May 2011

Friction Stir Welding process introduces a degree of deformation in the material that is related to process parameters. They directly regulate the heat input of welding process and then the morphology and the microstructure characteristics. In the present work, an investigation was carried out on 6082T6 butt joints obtained by Friction Stir Welding process. The microstructure and mechanical characterizations were performed before and after a post-welding treatment at 535°C for 2 hours and cold deformation. The thermal stability of fine recrystallized grains in the nugget zone depends on process parameters and post-welding heat treatment and it has unusual consequences on mechanical properties. In fact abnormal grain growth, that occurs in the nugget zone, increases ductility of the joints and homogenizes the hardness profile of the whole joint.
The Effect of Grain Boundary State on Deformation Process Development in Nanostructured Metals Produced by the Methods of Severe Plastic Deformation
Authors: Naydenkin Evgeny V. , Grabovetskaya Galina P. , Ivanov Konstantin
Published: May 2011

In this review the investigations of deformation process development are discussed which were carried out by tension and creep in the temperature range Т<0.4Tm (here Тm is the absolute melting point of material) for nanostructured metals produced by the methods of severe plastic deformation. The contribution of grain boundary sliding to the total deformation in the above temperature interval is also considered. An analysis is made of the effect of grain size and grain boundary state on the evolution of grain boundary sliding and cooperative grain boundary sliding in nanostructured metals.
The Influence of Stacking Fault Energy on the Cold-Rolling Cu and Cu-Al Alloy: Structure and Mechanics Properties
Authors: Yang Hao , Yang Peng , Tao Jing Mei , Li Cai Ju , Zhu Xin Kun
Published: May 2011

Sacking fault energy (SFE) is the key role in solving this problem of getting high strength and expected ductility simultaneously. This work adds Al as the procedure of decreasing SFE in Cu face-centered cubic. It is an economic and effective method to counterpart Cold-rolling at liquid nitrogen temperature to get high density deformation twin and ultrafine-grains size. After undergoing tensile and X-ray diffraction tests, Cu-4.5 wt.% Al plays the best performance on both strength and ductility. Thus there exist the optimal SFE of Cu-Al alloys which get both high strength and expected ductility simultaneously.
Polycrystalline Ni-Mn-Ga as a Potential Material for Magnetically Driven Actuators
Authors: Pötschke Martin , Roth Stefan , Gaitzsch Uwe , Hürrich Claudia , Böhm Andrea , Schultz Ludwig
Published: May 2011

Textured polycrystalline Ni-Mn-Ga alloys were prepared by directional solidification. Alloys were chosen to have the 5M modulated martensitic structure after proper heat treatment. A two-side mechanical training decreased the twin boundary pinning stress. The stress-strain behaviour for the training process and the magnetically induced stress depends on the training direction. Magnetic field induced strain was demonstrated in samples with a plate-like geometry. The influence of the microstructure on the magneto-mechanical behaviour is discussed.
Magnetic Phase Diagram of the Ferromagnetic Shape Memory Alloys Ni2MnGa1-xCux
Authors: Endo K. , Kanomata T. , Kimura A. , Kataoka M. , Nishihara H. , Umetsu R.Y. , Obara K. , Shishido Toetsu , Nagasako M. , Kainuma Ryosuke , Ziebeck K.R.A.
Published: May 2011

X-ray powder diffraction, permeability, magnetization and differential scanning calorimetry measurements were carried out on the magnetic shape memory alloys Ni2MnGa1−xCux (0 ≤ x ≤ 0.25). On the basis of the experimental results, the phase diagram in the temperature– concentration plane was determined for this alloy system. The determined phase diagram is spanned by the paramagnetic austenite phase (Para-A), paramagnetic martensite phase (Para-M), ferromagnetic austenite phase (Ferro-A), ferromagnetic martensite phase (Ferro-M) and the premartensite phase. It was found that the magnetostructural transition between the phases Para-A and Ferro-M can occur in the concentration region 0.12 < x ≤ 0.14 and that Ni2MnGa1−xCux has the characteristics of the phase diagram similar to those of the phase diagrams of Ni2+xMn1−xGa and Ni2Mn1−xCuxGa. In order to understand the phase diagram, the phenomenological free energy as a function of the martensitic distortion and magnetization was constructed and analyzed.
Role of Particle Size on Structural and Magnetic Behavior of Nanocrystalline Cu-Ni Ferrite
Authors: Dolia S.N.
Published: May 2011

Particle size has significant effect on the magnetic properties of fine particles. In this work, Cu0.2Ni0.8Fe2O4 nano-particles have been synthesized by the co-precipitation method. Different particle sizes were obtained by annealing the samples at various temperatures. The X-ray diffraction (XRD) patterns confirm the formation of cubic spinel structure. The particle size was found to enhance with increasing the annealing temperature. The saturation magnetization and the blocking temperature increase with particle size, which is a typical characteristic of the superparamagnetic behaviour. The dc magnetization measurements show that the samples are superparamagnetic above the blocking temperatures and the blocking temperature of the nanoparticles correlates with the size of the nanoparticles that is found to increase as the function of the particle size. The hysteresis curves show reduction in saturation magnetization in case of nanoparticles as compared to their bulk counterparts. This has been explained on the basis that the magnetic moments in the surface layers of a nanoparticle are in a state of frozen disorder. However, the saturation magnetization increases with particle size, which is a characteristic property of the single domain superparamagnetic particles.
Towards Transforming Colombo to a ‘Walkable’ City: Policies and Strategies
Authors: Dayaratne Ranjith
Published: May 2011

Colombo, like many emerging cities in Asia is plagued with the ills of overcrowding, ad-hoc developments and chaotic systems of travel and transport. Once considered one of the best cities in Asia, its walkable streets have been inundated with obstructions to the pedestrians and Colombo has increasingly become a city in which walking is a hazardous activity. In the current interest in transforming Colombo to a more liveable graceful city, facilitating walking through its public spaces springs to the forefront as an indisputable strategy to be employed in urban re-developments.This paper examines the issue of facilitating walking in the city of Colombo and discusses the problems and potentials of transforming it to a pedestrian-friendly city as perceived by the people. Based on the findings of a user response study carried out in 2008, it outlines the major issues raised by the urban dwellers of Colombo and proposes some remedial actions that could be taken. In the context of increasing urbanisation where vehicular traffic and the provision for it has begun to dominate the city spaces, the paper argues for a shift of approach in its urban development practice in order to improve its walkability so that the city could once again become a delightful place. DOI: 10.4038/besl.v9i1-2.3055 Built - Environment - Sri Lanka - Vol. 09 - 10, Issue 01 - 02 : 2011 pp.2-13