bluuebunny/crossref_metadata_2025 huggingface dataset:
An Investigation on the Behaviour of Concrete with Waste Tyre Rubber Fibres as a Partial Replacement of Coarse Aggregate
Authors: Kumaran G. Senthil , Lakshmipathy M. , Mushule Nurdin
Published: October 2011

Concrete is an excellent structural material and considered as essential for the modern civilization and human society. Now, use of waste tyres in concrete has become technically feasible and the concrete is being considered as light weight concrete. The composites were formed with 0%, 5%, 10%, 15%, 20% and 25% of fibers replaced by coarse aggregate weight. The fibers were of different lengths (L) such as 25mm, 50mm and 75mm had holes of diameters (D) 4mm, 5mm and 6mm. The holes functioned as anchors in the cement matrix so that the tyre fibres shall not be separated while placing in the mould. The 3rd, 7th and 28th day’s compression strength and crack patterns were observed on cubes. Split tensile strength on 14th and 28th day were tested on cylindrical specimens. Test results have shown that the increase in rubber content decreases the compressive strength, but, increases the strain energy while conducting the split tensile tests. The composite with fiber specimen L50-D5 and L50-D6 with 10% replacement of coarse aggregate had shown better results than other specimens. However, further studies are needed to reveal the hidden properties of tyre fiber modified concrete.
Design and Testing of a Mini-Plant for Conversion of Organic Waste to Biogas
Authors: Ebunilo Patrick , Otiede David
Published: October 2011

An experimental organic waste to biogas conversion mini-plant that works by anaerobic digestion has been designed, fabricated and tested. The demonstration involved the use of primarily, a biodigester and few other components. The organic waste was made into slurry and digested anaerobically for 14 days at an ambient temperature range of 28 to 32°C. The flame of biogas generated burnt with smokeless blue flame, indicating the presence of a colourless odourless gas called methane. The biodigester achieved a conversion efficiency of 64 percent. This equipment can be used to meet a good percentage of the fuel needs in Nigeria.
Property Analysis for Correlation of Specific Energy with Penetration Rate and Bit Wear Rate
Authors: Adebayo B. , Bello W. A.
Published: October 2011

This study evaluates rock properties for correlation of specific energy with penetration rate and bit wear rate. In order to achieve these objectives five rock samples were obtained from the study area. These samples were tested in the laboratory for uniaxial compressive strength and tensile strength using 1100kN compression machine and point load tester respectively. Also, the mineral composition of the samples was determined by thin section examination. Bit deterioration was measured with digital vernier calliper at regular intervals. The specific energy was determined from field data using empirical equations. The results of the uniaxial compressive strength of the five rock samples varied from 165-320 MPa and were classified as having very high compressive strength characteristics. The point load strength index of the samples had values ranging from 5.50 – 10.67 MPa representing the tensile strength. The result of the statistical correlation matrix revealed that penetration rate and bit wear rate are dominant factors affecting the prediction of specific energy having high coefficient of correlation. The regression model had multiple coefficient of correlation of R2 = 0.893 which means that 89.3% of variation in specific energy could be attributed to variation in penetration rate and bit wear rate. Ultimately, computer programme DRILLING PROFESSIONAL 2009 was developed to compute penetration rate, wear rate and specific energy when necessary inputs are supplied. This gives quarry operators advance information on time of drilling and bit consumption.
Variability in Rock Strength Prediction Using Ultrasonic Pulse Velocity
Authors: Eze E.O.
Published: October 2011

Three rocks - biotite granite, dolerite, and marble - were studied for the use of ultrasonic pulse velocity in predicting their uniaxial compressive strength. The rocks differed in mineralogy, texture, and strength. The mineralogy and texture influence to varying degree the strength and the pulse velocity. Correlations between the compressive strength and the sonic velocity were highest in the marble (0.94-0.97), and lowest in the granite (0.68). The low correlation in the granite was attributed to the different mineral contents, the presence of biotite, the complexity in the grain boundary shape and the tortuosity of the wave path through the rock. The use of acoustic impedance and stiffness constant improved the strength of correlation in the marble but not in the dolerite and granite.
Performance Indicators for Sapele Thermal Power Station, Nigeria: 1997-2006
Authors: Obodeh O. , Isaac F. O.
Published: October 2011

Performance indices as measured by percentage of shortfall of energy generated, load factor, utilization factor and capacity factor of Sapele thermal power station, Nigeria in the period 1997 to 2006 is presented. The thermal station uses both steam and gas turbines. The station consists of six units of steam turbine and four units of gas turbine with total installed capacity of 1020 MW. But it was established that less than 17 % of the installed capacity was available. The percentage shortfall of energy generated for the period under review ranged from 27.4 to 49.1 %. This was due to aging of the plant, improper operation and maintenance. The load factor was between 39.9 and 64 % as against international best practice of 80 %. The inability of Power Holding Company of Nigeria (PHCN) to do turn-around maintenance on the plant was advanced for the dismal value. Average plant availability of the plant for the studied period was less than 21% as against Industry best practice of over 95 %. The capacity factor was even more dismal. For the period under review, it ranged from as low as 5.49 % in 2006 to the highest value of 17.19 % in 1997. Low capacity factor indicates excessive plant failure. Measures to improve the performance indices of the plant have been suggested such as training of operation and maintenance (O & M) personnel regularly, improvement in O & M practices, proper spare parts inventory, organizing regular management meetings and improving general housekeeping of the plant.
Development of a Small Scale Machine for Recovering Bush Mango Kernel from Bush Mango Nut
Authors: Olaniyan A.M.
Published: October 2011

A small scale machine for recovering bush mango kernel from bush mango nut was designed, constructed and tested. Consideration was given to the techno-economic status of the micro and small scale bush mango processors living in the rural communities who are the intended users of the machine. The functional parts of the machine included feeding unit, cracking unit, winnowing unit and frame. The machine was tested with processed and unprocessed bush mango nuts and results showed that average cracking efficiency of 57.3 % and 19.3 % respectively were obtained. Powered by a 3 hp single-phase electric motor, the machine was constructed with readily available materials. It is recommended that, before cracking, bush mango should be processed by completely removing the fibrous mesocarp as this improves the efficiency of cracking and separation.
Computer Aided Analysis of Thermal and Mechanical Design of Shell and Tube Heat Exchangers
Authors: Adelaja A.O. , Ojolo S.J. , Sobamowo M.G.
Published: October 2011

Most of the attempts made at designing shell and tube heat exchangers have been limited to thermal hydraulic design. This study however, considers both the thermal and mechanical design of the E-type shell and tube heat exchanger with the aid of computer programming. It involves developing a simple user-friendly computer programme for the heat transfer calculations and ensures that the computational time is kept minimal. The algorithm is designed such that after the conditions for the thermal analysis are satisfied, the programme automatically proceeds to the mechanical design. The programme written in Visual Basic was tested using a model and the simulated result presented.
Development and Performance Evaluation of a Multipurpose Dryer
Authors: Ilechie C.O. , Aibangbee G.F. , Ogblechi S.R. , Abikoye B.O.
Published: October 2011

In this work an electrically operated thermostatic multipurpose dryer is developed and evaluated. It measures 2,300mm long, 600mm wide and 1,100mm high and consists of 50mm x 50mm mild steel angle iron and aluminium sheet wrapped all over it. The interior of the dryer is painted black to ensure maximum heat retention within the system for faster drying. The multipurpose dryer is constructed with the incorporation of vents to enable uniform air circulation within the system. This is to facilitate uniform drying of specimens. The development of the dryer is to help minimize losses of agricultural produce by drying them to the required moisture content that will enable them to be kept in storage. The dryer was used to determine the moisture content of coconut meat and it was found to be 53.47% and 1.15% wet and dry basis respectively. The dryer could be used to dry all agricultural produce to the required moisture content that will enable them to be preserved. This is achieved by selecting the appropriate temperature graduated on the dryer. The equipment has hot air at a velocity of 18.7m/s distributed uniformly across specimen trays in the drying chamber. As the hot air passes over agricultural produce in trays, the drying process takes place. It has been found that the multipurpose dryer is suitable for drying agricultural produce and other allied produce to the required moisture content up to a maximum temperature of 1100 C. The dryer efficiency was determined to be 75%.
Optimal Two-Way Conductor Design Using Computable Convex Functions Approach
Authors: Asemota Godwin Norense Osarumwense
Published: October 2011

Effective and efficient electricity load-and demand-side management depends on the transmission, distribution and interconnecting networks of properly designed and adequately sized conductors to carry the produced electrical power to the ultimate consumers. A two-way optimal conductor design using computable convex functions was investigated in this paper. Composite materials whose area approaches the minimum and for which both the maximum vertical and horizontal currents simultaneously satisfy the Laplace’s equation, was considered. The resulting variational problem was homogenised or relaxed and thence, made polyconvex through the Lagrangian multipliers and Green’s identity. The main reason for the convexification of this design problem is that over the interval of convexity, there is only one minimum. This is so because any polyconvex function, which satisfies the boundary conditions is always minimising. That fact can strengthen many of the results we might desire while using the developed computable convex functions to show that no conductor area can be lower than that of the optimal two-way conductor designed in this study. Although the conductor proposed in this study would be more expensive than the conventional steel-cored cables, the economics of much higher current carrying capacities makes it more attractive. Additionally, their light weight requires that no new transmission towers are installed; they will suffer less sag, able to operate at much higher temperatures than aluminium conductor steel reinforced (ACSR) and less blackouts.
Computer Aided Design of Power Transmission Screw
Authors: Akpobi John A. , Edokpia R. O. , Oladeinde M.H.
Published: October 2011

In this work, computer aided design software for the analysis and design of Power Transmission Screws, is presented. In designing the software, the relevant equations and models were assembled and carefully programmed using Microsoft Visual Basic.Net (an object oriented programming language). Also visual representation of the solution to problems of Power Transmission Screw was developed, in form of graphical solutions. The software was tested on a variety of bench mark problems. The solutions obtained were highly accurate, thus validating the performance of software.
Modeling and Parametric Study of Cover Plate Strengthen-Beam Flange Weaken Beam-to-Column Connection for Steel Moment Frame
Authors: Zhang Yan Xia , Li Yun Peng , Wang Lu Yao , Yang Fan
Published: October 2011

Based on the previous experiments and theoretical analyses, finite element analyses (FEA) and parametric study on seismic behavior of Cover Plate Strengthen-Beam Flange Weaken Beam-to-Column (CPSBFW) connection are executed by using ABAQUS. Suggestions on design conceptions and details of the cover plate strengthen-beam flange weaken beam-to-column connection are presented in this paper, and that provide valuable reference for design of beam-to-column connections in steel structures.
Research on Controlling Mechanism of Temperature Crack of High Performance Concrete on Freezing Shaft Lining in Special Thick Alluvium
Authors: Jiang Xi Ping , Wang She Liang , Yong Yu Li
Published: October 2011

This paper researches on the hydrating capacity of HPC on freezing shaft lining in special thick alluvium as well as the temperature state and temperature stress of lining. Through building and calculating temperature field model of HPC on freezing shaft lining, it elaborates that temperature stress is the leading cause of lining crack. And we should control such a problem by tackling temperature difference and deformation; According to the principle of “working resistance and relaxation concurrently”, stuffing emulsified asp halt mixture between the inner and outer linings (60mm) as a sliding layer can lessen restriction between them and reduce temperature, thus control the problem of well case cracking of HPC on freezing shaft lining fundamentally. The control effect is obvious after practicing in some mine projects in Huainan mining area. Keywords: high performance concrete on freezing shaft lining，temperature stress，temperature difference and deformation，emulsified asphalt mixture, sliding layer
Experimental Study of Aerodynamic Interference Effects on Double Thin-Walled Hollow Pier in Tandem Arrangement
Authors: Wang Jie , Zhao Jin Yun , Liu Jian Xin
Published: October 2011

Against the problem of the aerodynamic interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test．The space between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 8 conditions. The research results have shown that the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The aerodynamic interference effects on parallel bridge pier is shown mainly as follows: The tandem interval and wind direction angles are important factors affecting interference effects. The drag coefficient of pier downstream dropped and the drag coefficient of pier upstream changed but Not change significantly. There are also the aerodynamic interference effects of lateral force coefficient and torque coefficient between the piers upstream and downstream. The effects upstream are smaller and the effects downstream are larger.
Urban Agricultural Landscape Development Ideas on the Background of Urban and Rural Economic and Social Development
Authors: Fu De Ren , Huang Yao Zhi
Published: October 2011

Urban agricultural landscape depends on agricultural production, which is a composite function of the system with the combination of modern agriculture, rural culture, tourism and leisure as well as environmental education, farming experience. With the development of rural and urban, urbanization and agricultural modernization, metropolitan agricultural landscape has been given serious impact and challenge. The article analyzes relationship between rural, urban development and metropolitan agricultural landscape, then, it proposed strategy of the metropolitan agricultural landscape in Taihu Lake.
Analysis of Rutting Change Rule on Asphalt Pavement Overlay
Authors: Yao Zhan Yong , Zhou Li Jian , Shang Qing Sen , Guo Jian Min , Wang Na
Published: October 2011

According to the traffic load, road surface temperature, pavement structure parameters and the creep parameters of asphalt mixture of Jiqing highway, the freeway asphalt overlay rutting depth prediction model is constructed with ABAQUS finite element analysis software to simulate numerically on overlay rutting depth, and the relationship among the axial load times, overlay thickness and the rutting depth is studied at the same time. The results of the study show that, the theoretical calculation agrees well with measured results of rutting depth, the relationship among the overlay thickness, the axle load times and the rutting depth coincides with logarithmic function model, and in the same asphalt overlay height, anti-rutting ability on AC-20 is better than that of AC-25 ,AC-20 and AC-25 combinations.
Dynamic Regeneration of D301f Anion Exchange Resin to Remove Nitrate Nitrogen in Wastewater
Authors: Li Hong Yan , Li Shang Ming
Published: October 2011

Nitrate nitrogen in wastewater poses serious threat. D301f anion exchange resin can remove nitrate nitrogen in wastewater, its regeneration is one of the most important procedures, because regeneration efficiency has a direct impact on exchange capacity, water quality and regeneration agent consumption. D301f exchange resin column simulated nitrogen fertilizer plant wastewater (nitrate nitrogen300mg/L) for dynamic regeneration experiment. The results showed that, NH4OH regeneration agent dosage selected 3 to 4 times of theoretical amount more reasonable; regeneration solution concentration and temperature separately used 20% and 30°C better.
Study of Photocatalytic Degradation Mechanism of Butyl Enzyl Phthalate Ester
Authors: Lu Yan , Xi Li Ming
Published: October 2011

Under ultraviolet radiation, the photocatalytic degradation mechanism of Butyl enzyl phthalate ester (BBP) was studied with TiO2as the catalyst. As a result, BBP could be degraded efficiently, and the efficiency was 85% after 6h degradation. During the degradation process, the acidity of the degradation system changed obviously. The initial pH of the solution was 6.0, and it increased to 6.23 after 15min degradation, however it decreased to 3.89 after 6h degradation. Some photodegradation intermediates in the different photocatalytic steps were examined and analyzed by means of GC-MS. For the BBP, the photocatalytic degradation firstly reacted on the benzyloxy chain, and new material occured by the recomposition of the educts in the degradation.
Study on DOM Fluorescence Characteristics and Coagulation Mechanism of Secondary Effluent in Wastewater Treatment Plant
Authors: Ning Ya Na , Han Yun , Peng Dang Cong
Published: October 2011

In order to study the differences of dissolved organic matter (DOM) characteristics between the secondary effluent and the surface water, ultrafiltration (UF) was combined with three-dimensional excitation-emission matrix (EEM) spectroscopy to investigate the fluorescence characteristics of total DOM and different molecular weight fractions of them. Moreover, the DOM removal characteristics by coagulation were analyzed also under the respective optimal dosage of coagulant (PAC). The results showed that: DOM of secondary effluent contained four notable fluorescence peaks: humic acid-, fulvic acid-, aromatic protein- and soluble microbial product-like fluorophores, which were more than surface water. Coagulation was easy to remove macromolecules as humus, but the removal efficiency was not high enough for the relative small molecules as protein and microbial products. Fluorescence index (FI) indicated that secondary effluent after biotreatment were mainly from microbial sources. The correlation relationship between the humus-, protein-like fluorescence intensity and UV254 are strong in secondary effluent.
The Renovation Project of Chongqing Combined Sewerage System
Authors: Ou Yang Lin , Chen Zhi Li , Ren Zhen Jie , Yang Yi
Published: October 2011

The current problems of drainage system have been analyzed by addressing the current situation of combined sewerage system in Chongqing area. According to the geographical characteristics of the terrain and the existing pipeline system, advices on modification works have been proposed which would meet the demand of sustainable development of Chongqing drainage system.
Physical Fractional Step Method for Solution of 2D Water Flow around a Spur Dike
Authors: Liu Ming Qin , Liu Yu Ling
Published: October 2011

A numerical model for simulating of 2D flow around a spur dike was presented by using the physical fractional-step method. The water governing equations were separated into three parts. The first is a convective problem; the second is a diffusive problem; and the third is a source term. The advantage of this method is that in the convective-diffusion equation a more reasonable scheme for the convective and diffusive operator is adopted respectively. Numerical simulation for 2D flow around a spur dike was implemented. The comparisons with other numerical solutions show that the proposed method can be capable of dealing with 2D spur-dike flows.
Experimental Study of Establishing Fresh Air Micro-Circulation in the Dorm
Authors: Chen Xin
Published: October 2011

In winter, the heated dorms have a very poor air quality. This paper intends to establish a fresh air micro-circulation in the dorm through experiments. Three different outlet configurations are designed and made. By studying the distribution of CO2 concentration, air speed and temperature, the best outlet configuration and the best installing place are determined. In a room with a temperature of 24°C, CO2 concentration of 2000ppm, the fresh air device can lower the CO2 concentration in the immediate surroundings of the student down to 680ppm, while maintain a temperature of 21°C and an air speed under 0.18m/s.
Effect of the Type of Zeolite on Eliminating Nitrogen Load of Europhia Sediment Capping with Active Barrier System (ABS)
Authors: Xu Jin Lan , Liu Ai Ping , Kang Jun Chen , Huang Ting Lin , Dong Yu Hua , Wang Sen
Published: October 2011

Abstract: The application of an active zeolite barrier was investigated to improvement of eutrophication in the ancient Canal. For this, four types of zeolites (diameter: 1～2 mm) were applied in order to investage effect of the type of zeolite on N removal. The dosage of the zeolites was 1.46 kg.m-2 and the ammonium concentrations in overlying water were 3.47 mg/L. It is found that the capacity of elimination total N of the four zeolites was significant and decreased with the following order: Haiyu zeolite F1 > Aolin zeolite F2 > Natural zeolite F3 > Calcium zeolite F4. In addition, the results show that zeolite F1 and F2 belong to N inhibiting type as TN concentration of overlying water quickly reduced to 2.53 mg/L, 3.7 mg/L, and the corresponding removal efficiency of TN is as high as 56% and 35.6% after covering zeolite F1 and F2. The results indicated that the consumption rates of ammonia nitrogen in this system is greater than or equal to release rates of ammonia from sediment. However, TN concentration of overlying water still rise to high level (1.57 times of initial TN) when covering zeolite F3 and F4 (N non-inhibited type). Therefore, it is considered that the Haiyu zeolite should be the best barrier materials to clean sediment of the ancient Canal.
The Removal of Inorganic Anions from Municipal Secondary Effluent Using Magnetic Ion Exchange Resin
Authors: Yang Jian , Chang Jiang , Gan Yi Ping , Gao Jin Hua
Published: October 2011

The primary objective of this research was to evaluate the effectiveness of a magnetic ion exchange process (MIEX) in removing inorganic anions from municipal secondary effluent. Municipal secondary effluent drew from Gaobeidian wastewater treatment plant treating about 800,000 m3/day domestic wastewater. In the pilot experiment, MIEX resin removed 37.01% phosphorus, 31.62% nitrate, 36.06% ammonium and 64.34% sulphate from municipal secondary effluent. Phosphorus concentration in resin influent influenced reclaimed water treatment efficiency. Phosphorus removal rate was positively correlated with the concentration in influent. If phosphorus concentration in influent was >0.82mg/L, phosphorus removal of >52% was achieved. Nitrate and sulphate removal had same variation laws. 18.92% average removal rate of nitrate in middle period was lower than 35.06% and 39.25% average removal rates in earlier and latter periods respectively. The average removal rates of ammonium in three periods were 83.03%, 43.51% and 84.29% respectively. Removed ammonium of each sample was about 0.250mg/L, average removal rate was 36.06%. Lower ammonium concentration in influent could cause higher removal rate. Otherwise, magnetic ion exchange process could increase turbidity and could not disinfect, the resin effluent will be treated with coagulation-sedimentation and ozonation for groundwater recharge research with reclaimed water.
Wind Environment Assessment in High-Density Semi-Tropical Urban Area: Analysis of Typical Space in Shenzhen, China
Authors: Yuan Lei , Xu Xue Song , Shao Li Li , Li Bo , Wu Jia Meng
Published: October 2011

In this paper, CFD simulations of the wind environment of four typical urban spaces in Shenzhen are introduced. The boundary conditions for these numerical experiments and the criteria of assessment are chosen according to the geographical and meteorological characteristics of the city. The effects of different building configurations on air ventilation are discussed, which may probably give some useful information to urban planners when more comfortable and healthier spaces are expected.
A Study on Energy Saving of LEED-NC Green Building Rating System from Point Analysis
Authors: Zhou Tong , Tan Li Feng
Published: October 2011

LEED-NC is a green building rating system for new construction developed by USGBC. Since it’s born in1998, LEED-NC has become the most famous green building rating system and made a big success in market expanding. Many other countries, including China, not only use experience of LEED-NC for reference to their own green building rating criterions construction, but also participate in the LEED-NC certification directly. But, as a green building rating system, one of it’s primary objective is to make clear what is the biggest problem in sustainable process. Since 1970’s oil crisis, resource shortage has become a common problem hindering the social and economic development of all countries and districts. Any green building rating system can’t avoid this reality. Using method of “example points+baseline point”, this article makes points statistics of “Energy & Atmosphere” category and it’s inner credits relevant to building energy saving. Finally, we verify LEED-NC’s performance in energy saving is not so good as people’s expectation. When using experience of LEED-NC for reference to our own green building rating criterion construction, we must be very cautiously. And when participating in LEED-NC certification directly, we must keep a conscious mind.
Effect of Fly Ash and Slag Powder on Coefficient of Thermal Expansion of Concrete
Authors: Gao Gui Bo , Qian Chun Xiang , Wang Yong Wei
Published: October 2011

In order to study the effect of fly ash (FA) and slag powder (SP) on coefficient of thermal expansion (CTE) of concrete, the influence of FA and SP to CTE of concrete was compared, the influence of replacement proportion of FA to CTE of concrete was tested, and the unhydrate mineral admixture particles were observed with SEM and validate with Energy Spectrometry. The results showed that the influence of FA and SP to CTE of concrete is different, the CTE of SP concrete is near to the norm concrete，but is higher than the FA concrete; With the replacement proportion of FA increased, the CTE of concrete decreased; The per strength CTE increased obviously when the replacement proportion exceed 10%, and the decrease of strength badly when the replacement proportion of FA exceed 30%; The unhydrate mineral admixture particles is one of the most important factors that influence the CTE of concrete, and the mineral admixture could influence the composite and the microstructure of cement paste, then cause the change of porosity and density.
Design and Analysis of the Support System for Cement-Base Formwork
Authors: Song Xiao Ruan , Qu Yu Ting , Zhang Xiao Yun , Niu Wei , Jiang Yu Feng
Published: October 2011

The cement-base composite formwork reinforced by FRP is developed to act as permanent construction formwork. Considering such properties as the minor stiffness out of the plain and the smaller bending resistance of the formwork, the matched cross support device is designed which can be recycled. In this paper, components of the support device and the corresponding functions are introduced, the technological process is described. By means of finite element program, the appropriate support distances of formwork during concrete placement are calculated, the stress and deformation performances are also analyzed. In the end, economic benefit and environment efficiency of the permanent formwork system are discussed. The above research results indicate the feasibility and economy of the support system, which present a gist for investigation and application of the permanent FRP cement composite formwork.
Study on the Thermal Properties of Paraffin/Expansion Perlite Composite Phase Change Mortar
Authors: Wang Qing , Zhang Jing , Da Jing , Zhao Hui , Ran Kun
Published: October 2011

Phase change materials were prepared by the paraffin wax as phase change materials and expanded perlite as adsorption carrier in this paper. Phase change mortar was prepared by part of the sand been replaced. The heat ability which adjusts and stores heat in the heating and cooling process with different phase change materials was researched and its mechanical properties were tested and evaluated.
Scattering of Subsurface Cylindrical Cavity near Multiple Semi-Cylindrical Alluvial Valleys under Incident SH-Waves
Authors: Wang Hui Wen , Sun Xiao Juan , Yang Zai Lin
Published: October 2011

The scattering of subsurface cylindrical cavity near multiple semi-cylindrical alluvial valleys under incident SH waves is studied in this paper by using methods of auxiliary function, complex function multi-polar coordinates. The model is divided into two parts, Domain I is multiple semi-cylindrical alluvial valleys, and Domain Ⅱ is an elastic half space with several subsurface circular cavities near multiple semi-cylindrical alluvial valleys. A series of infinite algebraic equations is then obtained based on the displacement and stress continuity condition on “common boundary” of two parts after constructing the associated displacement and stresses expressions of each part. Numerical examples illustrate that material parameters of semi-cylindrical alluvial valleys have great impact on DSCF around subsurface cavity and DSCF dose not always decrease as wave number increases especially under incident waves with high frequency when the alluvial valleys are “softer”.
Coupling Effect between Single Key Strata and the Overburden Thick Sandy Soil Layer
Authors: Zhang Pei , Huang Qing Xiang
Published: October 2011

Through the simulation model test, coupling effect between single key strata and t overburden thick sandy soil layer is studied, failure character of thick sandy soil layer is obtained. Meanwhile, load transmitting law on the key strata(key block) is found. This discovery will make progress on dynamic roof structure theory.
A Study on the Eco-Compensation for the Sustainable Development of the Energy and Chemical Industry Base in Northern Shaanxi
Authors: Yan Wen Zhou , Hua Shan , Niu Jia
Published: October 2011

The sustainable development of the Northern Shaanxi area has been severely restricted by the increasingly serious issue of the environmental pollution and ecological destruction in the energy and chemical industry base there. Regarding this problem in the energy and chemical industry base in Northern Shaanxi, this paper explored the eco-compensation mode, established the model for the quantification of the compensation fee, and constituted the eco-compensation standard for each county within the base area. Through the establishment of the eco-compensation mechanism, the conflict between the energy development and ecological environment protection could get alleviated, the natural resource could get moderate and sustainable developed, and the ecological environment could sustainably get back and obtain melioration, all of which will facilitate the realization of the sustainable development of the energy and chemical industry base in Northern Shaanxi.
Study on the Permeability Model of the Porous Concrete
Authors: Zhao Fang Ran , Chen Mian Mian , Ding Zhao Lu
Published: October 2011

This paper presents an effective model which can equivalently regard the pores in the porous concrete as a series of capillary bundles with the same diameter due to the complexity of the pores in the porous concrete. The proposed model was used to calculated the total flows of all capillary bundles in the test piece by the single capillary bundle calculation approach from the Hagen-Poiseuille theorem, and together with the well known Darcy theorem to determine the relationship among the flow of the porous concrete, the diameter of pore and the minus of up and down water pressures. The experimental results show that the permeability of the porous concrete mainly depends on the pores with diameter more than 4.12mm, and the pore structure changes obviously when the valid porosity of the porous concrete is greater than 25%.
Study on Energy-Consumption Management and Energy-Saving Analysis System for the Large Public Building Based on WebAccess
Authors: Lu Xiao Lin , Wang Lei
Published: October 2011

Aim at the current situation of high energy-consumption of the large public building，proposed a WebAccess–based energy-consumption management and energy-saving analysis system.And it be used Zigbee distributed energy consumption measurement net for data remote transmission. The status of energy consumption in the future can be predicted through energy-consumption databases and energy-consumption models were built. The system can real time monitor and manage the energy-consumption status in large public constructions. It can provide a favorable foundation not only for energy conservation and reformation of those completed large public building, but also for energy conserved operation and supervision of those new constructions. This can help to achieve the goal of energy conservation and energy-consumption reduction in large public building.
Study on the thermal stability of Controlled Permeability Formwork
Authors: Guo Xiao Meng , Li Jian Qiang , Zeng Xian Sen , Hong De Dao
Published: October 2011

In this study, the thermal properties of a kind of new geotextile materials, so called controlled permeable formwork (CPF), were studied. Thermo-gravimetric analysis showed that the weight of CPF didn’t change much between 0~350 °C. Dynamic mechanical analysis showed that the storage modulus of CPF reduced from 25 MPa to around 10 MPa when the temperature rose to above 100 °C. The strength of sample decreased slightly with the increase of the temperature. The breaking elongation changed slightly with a maximum at 80 °C. The CPF showed excellent thermal stability and was suitable for general use in construction work.
Experimental Research on the Relationship between Splitting Tensile Strength and Compressive Strength of Ceramisite Concrete
Authors: Yang Wei Jun , Wang Peng
Published: October 2011

Ceramisite concrete was charateristic of size effect as common concret. Through the experimentation of size effect on cubic compressive strength and axial compressive strength,and analysed and research coefficient of size effect by classical theoretics,elicit size effect of ceramisite concrete.
Comprehensive Utilization Technology of Rural Straws
Authors: Ying Li , Zhou Jing
Published: October 2011

In recent years, rural straw have been generated on the increase, accompanied by growing pollution, so utilization technology of rural straw was put forward, such as straw fermentation, straw manuring method, straw bio-reactor, straw fodder, straw-feeding edible fungus, producing protein, straw power generation, producing green building materials and for the weaving industry, etc, and do the analysis and comparison of its advantages and disadvantages of economic benefits, technology, provide guarantee to the application of utilization technology of rural straws.
Mechanical Properties of Modified Polypropylene Coarse Fiber-Reinforced, High-Strength, Lightweight Concrete
Authors: Zhang Rong Hui , Li Jian
Published: October 2011

In this study, the effect of micro-expansion high strength grouting material (EGM) and Modified polypropylene coarse fiber (M-PP fiber) on the mechanical properties of lightweight concrete are investigated. The influence of EGM and M-PP fiber on compressive strength , flexural strength and drying shrinkage of concrete are researched, and flexural fracture toughness are calculated. Test results show that the effect of EGM and M-PP fiber volume fraction (Vf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly enhanced, and the rate of shrinkage is obviously decreased. It is observed that the shape of the descending branch of load-deflection and the ascending branch of shrinkage-age tends towards gently with the increase of Vf. And M-PP fiber reinforced lightweight aggregate concrete is more economical.
Experiment on Thermophysical Properties of Reactive Powder Concrete
Authors: Liu Hong Bin , Tian Kai Pei , Liu Jin Hui , Ju Yang
Published: October 2011

In this paper, the thermophysical properties, such as thermal conductivity, thermal diffusivity, specific heat capacity and linear thermal expansion of reactive powder concrete (RPC) with different steel fiber volumetric fractions are investigated by means of thermophysical experiments. The empirical relationships of thermophysical properties with temperature and fiber volume are established. The results indicate the temperature and fiber volumetric fractions have different effects on the thermal properties of RPC.
Study on Energy Conservation Experiment for Heat Pipe Air-Conditioning System
Authors: Sun Shi Mei , Zhou Jing Min
Published: October 2011

In this paper, the experiments are made to research energy conservation effect of heat pipe air-conditioning system and the findings show that the heat pipe air-conditioning system is more energy efficient than conventional air-conditioning system; however, its energy saving rate will decrease with the increase of fresh air volume. Hence, in order to lower energy consumption, as long as the fresh air volume that guarantees the indoor air quality is selected, the lowest energy consumption that is required by air-conditioning system will be achieved.
Preparation and Characterization of Excellent Flame Retarded Rigid Polyurethane Foams
Authors: Zhang An Zhen , Zhang Yi He
Published: October 2011

Rigid polyurethane foams were excellent thermal insulation materials with widely used, which was highly flammable at the same time. In order to obtain safe application, flame retarded polyurethane foams were needed. In this paper, series flame retarded rigid polyurethane foams were prepared with loading different flame retardants such as ammonium polyphosphate, expandable graphite, red phosphorus, Tri (2-chloroethyl) phosphate and dimethyl methylphosphonate. The effects of flame retardants on the foaming-process and flame retardant property of the rigid polyurethane foams were investigated by otary viscometer and limiting oxygen index. The results showed that the combination of solid and liquid flame retardants was necessary to improve the flame retardant and different flame retardants played synergistic roles in rigid polyurethane foams. The limiting oxygen indexes of the foams could be up to 30wt% and 29.6% with 25wt% solid flame retardants and 10wt% liquid retardants, respectively.
Corrosion Behavior of Galvanized Steel in Simulated Rain
Authors: Zheng Xing Wen , Gong Min , Zeng Xian Guang
Published: October 2011

This paper investigates the corrosion behavior of galvanized steel in simulated rain using electrochemical method and surface analysis. The results indicate that the open circuit potential (OCP) for galvanized steel in simulated rain tends to be stable at -1.122V (SCE). With the increase of pH value, the corrosion current density (Icorr) for galvanized steel in simulated rain decreases initially and increases afterwards. Contrary to Icorr, the linear polarization resistance (Rp) for galvanized steel in simulated rain increases first and then declines. When pH value equals to 8.00, Icorr arrives at the minimum value whereas Rp reaches to its maximum. The findings also demonstrate that serious corrosion occurred on the surface of galvanized steel after immersing in simulated rain, besides, local corrosion was also observed, and the corrosion products are mainly zinc carbonate.
A Case Study to Assess the near-Glazed Workplace Thermal Performance
Authors: Qahtan Abdultawab , Keumala Nila , Rao S.P. , Alashwal Ali Mohammed
Published: October 2011

Passive solar control solutions have been widely used in buildings in tropic countries like Malaysia. It is assumed that these solutions may notably control the heat-gain of buildings. However, there is a lack of empirical studies that assess the extent of green-glazed techniques to sufficiently control solar heat-gain. The current study uses a case study approach to examine the thermal indoor performance, particularly the near-glazed workplace area. The performance of the ST Diamond Building (in Putra Jaya, Malaysia) has been examined in terms of: outdoor/indoor dry bulb temperature; glass surface temperature; heat flux through glazing; outdoor/indoor air movement; lux and; solar radiation. The results of the field analysis indicated that ST Diamond Building’s green-glazed solutions are efficient to control solar heat gain, which in turn will lead to reduce energy consumption for controlling solar heat loads.
Investigation on Residual Stress Distribution of H-Shaped Steel Section with Heavy Thick Steel Used in High-Rise Structures
Authors: Li Yuan Qi , Yan Qi , Sun Si , Shen Zu Yan , Yu Cheng Feng , Xu Hong Wei
Published: October 2011

In recent years, due to its excellent mechanical properties, especially its insensitivity of strength to thickness, high-rise structural steel with high performance and heavy thickness made in china was applied more and more widely in large-span and high-rise steel building structures. However, there are no reasonable design indexes based on design reliability analysis for the new material in relevant national standards. The high-rise structural steel was often used as H-section column with heavy thickness at present, and its residual stress distribution has significant influence on load-carrying capacity, which is one of the critical factors in reliability analysis of elementary members using high-rise structural steel. In this paper, with the block sectioning method, a detailed experimental investigation on the longitudinal residual stress distribution for H-section (H800×800×80×80mm), made from Q345GJ high-rise structural steel with thickness of 80mm is introduced. The contour of residual stress distribution in the whole section based on test was presented, and the regularity of the residual stress distribution of such a section was discussed. Meanwhile, the contour of yielding strength distribution in the whole H-shaped section with heavy thickness was obtained. It will provide some basic data for reliability analysis and further investigation of the structural members using high-rise structural steel.
Enlightenment and Application of Infinite Rapport Structure in Architectural Design
Authors: Shen Yuan , Chang Qing Hua , Wang Jia Liang
Published: October 2011

The infinite rapport structure is continuous repetition of a unit to fill its own space based on certain rhythm arranged. It has long been widely used in decoration of Architecture. This article makes a brief introduction of Geometrical Theory of Crystal Structure, studies the types and features of infinite rapport structure with different Dimension periodicity, and presents some typical design cases in architecture.
CFD Studies on the Heat Transfer Characteristics of a Horizontal Single-Tube in Fluidized Bed Heat Exchanger
Authors: Shen Cong , Guo Jian Xiang , Li Lin , Sun Jin Fei
Published: October 2011

The fluidized-bed heat exchanger is widely used in various industrial sectors with the high performance of its heat transfer, ability to adapt working conditions, anti-scaling properties and many other advantages. This paper takes a horizontal single-tube in fluidized-bed heat exchanger and the fluidized low-temperature smoke around the tube as the objects of study. Euler-Euler two-fluid model is taken in use. Heat transfer between gas-solid two-phase flows and water in single-tube is simulated. The temperature field and general heat transfer coefficient is analyzed by simulated graphics.
Basalt Fiber Reinforce Cement-Based Composite Materials
Authors: Tang Ming , Li Jing Qi , Liu Hong Liang , Chen Ning
Published: October 2011

In order to obtain the high performance cement-based consistent materials，the enhancement effect of basalt fiber was studied to develop the building mortar with a high flexural strength . Three factors such as basalt fibers fraction，water-cement ratio and sand-lime ratio are studied on compressive and flexural strength on 7 days and 28 days through the orthogonal experimental design and statistical analysis. According to project needs, the best combination of flexural strength is optimized. The enhancement mechanism and damage features are analyzed and evaluated by SEM, the result shows that the basalt fiber as enhanced component have a very good flexural strength enhancement effect, the maximum increased rate will reach 2.91 times. The effect on the strength of different age period is remarkable with different fiber fraction which is far greater than the water-cement ratio and sand-lime ratio. Basalt fiber have better physical and mechanical properties and better alkali resistance, some performance are second only to carbon fiber, and the cost of basalt fiber is far lower than carbon fiber, So the basalt fiber have a broad application prospects in the field of cement-based composite materials.
Specimen Molding Method of Chip Seal in Laboratory
Authors: Li Yu Hua , Li Hai Xiang , Liu Yu Xing , Chen Jing Yun
Published: October 2011

Chip seal is most frequently used as preventive maintenance (PM) treatments on asphalt pavement. However, it’s difficult to make the performance test of chip seal in laboratory. In this paper, the specimen molding method of chip seal is established in laboratory. Firstly, considering the structure and technique condition of the original pavement, a cushion layer of asphalt concrete (AC) is used as under layer of the specimen. Secondly, the construction process of chip seal is simulated in laboratory, which includes spraying emulsified asphalt and/or glass fiber, spreading aggregate, initial rolling and conservation, post-stage rolling and conservation in interval for some time. Lastly, visual inspection and sand patch test are used to evaluate the quality of the specimen. Research results show that the method of specimen molding and test in laboratory could relatively accurately simulate, evaluate and forecast the performance of the chip seal.