Concrete with Highly Active Rice Husk Ash

The overall aim was to investtgate the effect of highly active husk ash (RHA) produced by an industrial furnace on some properties of concrete. The strength, pore volume and pore distribution of concrete and the Ca(OH)2 content in concrete were investigated by JIS A 1108 ( Method of test for compressive strength of concrete), a mercury instrument porosimeter, and the thermogravimetric analysis, respectively. The results show that, with RHA replacement of cement , the compressive strength of concrete is increased evidently;the average pore radius of concrete is greatly decreased, especially the portion of the pores greater than 20nm in radius is decreased while the amount, of smaller pores is increased, and the more the RHA replacement, the less the amount of Ca(OH)2 in concrete. The latter two results are the main reasons for the strength enhancement of concrete.     

Quantitative Assessment on the Embodied Environmental Impact of Concrete with or without Fly Ash

According to the life cycle assessment and the environmental design method of industry prnduction, a quantitative assessment model for the embodied environmetal impact of concrete with or without fly ash was proposed. The environmental burden impact indicator （ EBII ）, the resources depletion impact indicator （RDII）, and the environmental impact comprehensive indicator （EICI） are defined. The specific environmental impact values of different grade concretes with or wittout fly ash were presented. In the embodied process of concrete with or without fly ash, the key potential environmental impact categories are global warming and dust endsskin, and it is an effective way for reducing the embndied environmental impact of concrete to mix fly ash and lower grade cenwat . The method presented in this paper makes it possible to quantitatively assess the embodied environmental impact of concrete with or without .fly ash. The results calculated in this paper can be used to quantitatively assess the life cycle environmental impact of construction materials and buildings.     

Properties of High Volume Fly Ash Concrete Compensated by Metakaolin or Silica Fume

The compressive strength and dynamic modulus of high volume fly ash concrete with incorporation of either metakaolin or silica fume were investigated. The water to cementitious materials ratio was kept at 0.4 for all mixtures. The use of high volume fly ash in concrete greatly reduces the strength and dynamic modulus during the first 28 days. The decreased properties during the short term of high volume fly ash concrete is effectively compensated by the incorporation of metakaolin or silica fume. The DTA results confirmed that metakaolin or silica fume increase the amount of the hydration products. An empirical relationship between dynamic modulus and compressive strength of concrete has been obtained. This relation provides a nondestructive evaluation for estimating the strength of concrete by use of the dynamic modulus.     

Compressive Strength, Pore Size Distribution and Chloride-ion Penetration of Recycled Aggregate Concrete Incorporating Class-F Fly Ash

The effects of fly ash on the compressive strength, pore size distribution and chloride-ion penetration of recycled aggregate concrete were investigated. Two series of concrete mb：tures were prepared. The concrete mixtures in series I had a water-to-binder ratio and a cement content of 0.55 and 410 kg/ m^3 , respectively. The concrete rnixtures in series II had a water-to-binder ratio and a cement content of 0.45 and 400 kg/ ml respectively. Recycled aggregate was ased as 20% , 50% , and 100% replacements of natural coarse aggregate in the concrete mixtures in both series. In cutdition, fly ash was used as 0% , 25% and 35% by weight replacements of cement. The results show that the compressive strengths of the concrete decreased as the recycled aggregate and the fly ash contents increased. The total porosity and average porosity diameter of the concrete increased us the recycled aggregate content increased. Furtherrruore , an increase in the recycled aggregate content decreased the resistance to chloride ion penetration. Nevertheless, the replacement of cement by 25% fly ush improved the resistance to chloride ion penetration and pore diameters and reduced the total porosity of the recycled aggregate concrete.     

Self-Healing Concrete with Crystalline Admixture——A Review

The scope of the present paper is to understand the effects of crystalline admixture on the selfhealing capacity of the cementitious composites. Previous studies were examined and a conclusion was drawn to the effect that different additives to crystalline admixture tend to improve self-healing of concrete for larger cracks. It is recommended that initial treatment with chemical admixture can stimulate and heal further cracks and it has the better repeatability trend in mixing with the concretes and mechanical recovery is possible even under repetitive preloading. Effective self-healing with chemical admixtures even under open-air exposure, leads to study the importance of a service ability design parameter including the maximum allowable crack width by repeatability analysis as a function of the exposure with the concept of sealable crack width.     

Characteristics of Smart Concrete with Fiber Optical Bragg Grating Sensor

Based on the adrantages of the fiber Bragg grating sensing technology, this paper presents a principle of a novel smart corwrete with fiber optical Bragg grating sensor, analyses the theory and characteristics,illustrates the key technology and method to make the fiber Bragg grating sensor for the smart concrete, and proves the feasibility with experiments.The results inlicate that the smart concrete with fiber Bragg grating sensors is feasible in the structure monitoring and damage diagnosing in the long run.     

The Compression-deformation Behaviour of Concrete with Various Modified Recycled Aggregates

Modified recycled aggregates were prepared with three different cement-admixture grouts. The physical properties, such as water absorption, apparent density, crushing index, slump and compressive strength of the recycled aggregate and the recycled concretes were tested, and the tests for the compression-deformation behavior of the concretes were also performed. The experimental results show that the cement-Kim powder grout is satisfied for enhancing the recycled concrete, and the modification of the recycled aggregate with the grouts can improve the toughness and the deformation ability of the concretes.     

Assessment on Chloride Contaminated Resistance of Concrete with Non-steady-state Migration Method

A preparation technology of ctdoride contaminated resistant concrete was presented. The newly developed non-steady-state migration test method was employed for the evaluation of chloride ions diffusion coefficient of the concrete. The experimental results show that this method has a good correlation with the traditional NT Build 443 method, and it provides an effective and quick approach to assess the resi,resistant capacity of concrete aginst chloride ions.     

Expansive Performance of Serf-stressing and Self-compaeting Concrete Confined with Steel Tube

Combining with the technology of self-compacting concrete, self-stressing concrete and concrete-filled steel tube, we can get self-compacting and self-stressing concrete-filled steel tube. In order to study the expansive mechanism of self-stressing concrete, the continuous observation of 47 days on six specimens was carried on. The specimens have different steel area to concrete area ratio. The expansive process in hoop and axial direction were studied, and the expansive mechanism was discussed too. The experimental results identify that the creep and elastic deformation take a large proportion in effective free expansion. The calculating formulas of self-stress in hoop and axial directions were presented here.     

Automatic Detection of Moving Target with an Active Camera

ＡｕｔｏｍａｔｉｃＤｅｔｅｃｔｉｏｎｏｆＭｏｖｉｎｇＴａｒｇｅｔｗｉｔｈａｎＡｃｔｉｖｅＣａｍｅｒａＦＥＮＧＢｉｎｇｒｉ；ＹＡＮＧＷｅｉ；ＺＨＡＮＧＴｉａｎｗｅｎ；ＨＵＡＮＧＱｉｎｇｍｉｎｇ；ＳＨＩＨａｉｆｅｎｇ冯秉瑞，杨威，张田文，黄庆明，师海峰（...     

Expansive Performance of Self-stressing and Self-compacting Concrete Confined with Steel Tube

Combining with the technology of self-compacting concrete,self-stressing concrete and con-crete-filled steel tube,we can get self-compacting and self-stressing concrete-filled steel tube.In order to study the expansive mechanism of self-stressing concrete,the continuous observation of 47 days on six specimens was carried on.The specimens have different steel area to concrete area ratio.The expansive process in hoop and axial direction were studied,and the expansive mechanism was discussed too.The experimental results identify that the creep and elastic deformation take a large proportion in effective free expansion.The calculating formu-las of self-stress in hoop and axial directions were presented here.     

Simulation of Random Crack. Generation in Concrete Members with Uniform Stress Fields

1 Introduction In practice, concrete members are frequently encountered for which theory predicts uniform stress fields. For example, in a truss member of constant cross section, every material point, except in the end regions, is expected to be subjected to exactly the same stress. Similarly, in flexural members with re- gions of constant moment, the stress in extreme fibers is theoretically constant along such regions[1]. If the tensile strength of the concrete is likewise assumed to be the …     

Synthesis and Characterization of Chitosan-based Biomateriais Modified with Different Active Groups and Their Relationship with Cytotoxicity

The cytotoxicity profile of three chitosan derivatives with different affinity to water was evaluated in vitro.The derivatives selected were carboxymethylated-chitosan(CMCH),linoleic acid modified- chitosan(LACH)and deoxycholic acid modified-chitosan(DACH),respectively,and the results of FTIR and NMR confirmed the successful modification.Cytotoxicity of these polymers was investigated via the red blood cell lysis assay and the MTT assay.The red blood cell lysis test showed that CH elicited a certain level of red blood cell toxicity,while CMCH,LACH and DACH all displayed low membrane damaging effects, with the hemolysis rates of 2.385%,1.560% and 4.404%,respectively,which comes well within permissible limit(5%).The MTT assay revealed that CH exhibited significant inhibitory effect on fibroblast proliferation at higher concentration,while its three derivatives showed no cytotoxicity.CMCH had stimulatory effects on fetal mouse fibroblast proliferation.Differences in cytotoxicity of CH and its derivatives may result from the specific chemical modifications leading to the alteration of molecular charge density and type of the cationic functionalities,structure and sequence,and conformational flexibility.     

Synthesis and Characterization of Chitosan-based Biomaterials Modified with Different Active Groups and Their Relationship with Cytotoxieity

The cytotoxicity profile of three chitosan derivatives with different affinity to water was evaluated in vitro. The derivatives selected were carboxymethylated-chitosan （CMCH）, linoleic acid modifiedchitosan （LACH） and deoxycholic acid modified-chitosan （DACH）, respectively, and the results of FTIR and NMR confirmed the successful modification. Cytotoxicity of these polymers was investigated via the red blood cell lysis assay and the MTT assay. The red blood cell lysis test showed that CH elicited a certain level of red blood cell toxicity, while CMCH, LACH and DACH all displayed low membrane damaging effects, with the hemolysis rates of 2.385%, 1.560% and 4.404%, respectively, which comes well within permissible limit （5%）. The MTT assay revealed that CH exhibited significant inhibitory effect on fibroblast proliferation at higher concentration, while its three derivatives showed no cytotoxicity. CMCH had stimulatory effects on fetal mouse fibroblast proliferation. Differences in cytotoxicity of CH and its derivatives may result from the specific chemical modifications leading to the alteration of molecular charge density and type of the cationic functionalities, structure and sequence, and conformational flexibility.     

Highly Ordered Carbon Nanotube Arrays with Open Ends Grown in Anodic Alumina Nanoholes

Highly ordered rmdtiwalled carbon nanotube arrays were fabricated by pyrolysis of acetylene within anodic alumina templates. Nanotubes are very uniform irt diameter and open at both ends. High resolution transmission electron microscopy and electron diffraction analysis show that the carbon nanotubes are well graphi-tized. These standing and open carbon nattotubes are possible to offer a potential elegant technique for electron emitting devices, chemical functionalization and nanotube composites.     

Solidification of Municipal Solid Waste Incineration Fly Ash with Cement and Its Leaching Behaviors of Heavy Metals

The solidifying qffect of cement addition on municipal solid waste incineration fly ash ( MSWFA for short, collected from the gas exhaust system of MSW incinerator), the interaction of MSWFA with cement and water and the leaching of heavy metals from cement-solidified MSWFA are investigated. The main results show that : ( 1 ) when MSWFA is mixed with cement and water, 112 evolution, the formation and volume expansion of AFt will take place, the volume expansion can be reduced by ground rice husk ash addition ; (2) heavy metals do leach from cement-solidified MSWFA and at lower pH more leaching will occur; (3) compared with cement - so-lidified fly ash, the leachate of solidified MSWFA is with higher heavy metal contents ; (4) with the increment of cement addition leached heavy metals are decreased ; and (5) concentrations of Zn , Mn , Cu and Cd in all the leachates can meet the relevant Standards of Japan, but as the regulations for soil and groundwater protection of Japan are concerned, precautions against the leaching of Pb , Cl^- and Cr^6 and so on are needed.     

Active vibration control of multibody system with quick startup and brake based on active damping

1 INTRODUCTIONIn micro-electronics manufacture , a lot ofequipment must move fromone position to an oth-er position,then stop and perform a task. Afterthat they will start at another position.Fromstar-tup to brake , if the vibration of system is toogreat ,the vibration range may exceedthe precisionof fixed position.In recent years , many scholars[1 10]have re-searched suppression of vibration by utilizing pie-zoelectric structure . Kaji wara et al[2]studied ac-tive control of the vibratio…     

Psychoanalysis of Claudia in Anne Rice＇s Interview with the Vampire Based on Freud＇s Personality Theory

为了对《夜访吸血鬼》中克劳迪娅这个人物做出新的阐释,加深读者对该人物性格及其悲剧命运的理解。从精神分析的角度,运用弗洛伊德的人格理论学说,具体分析克劳迪娅精神上本我、自我、超我的发展过程和特点,并进一步阐明造成其人格特征的成因。