The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut h...The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut hard metals. In this study, preliminary design of experiment （DOE） test program was conducted to investigate and i- dentify the factors affecting tool wear at the micro-scale with hard material. Analysis of variance （ANOVA） and Taguchi method were efficient to determine appropriate cutting condition and the effect of parameters. A simple model was also developed to predict the width of slots on the workpiece along the cutting length. The obtained re- suits can provide the basic guidelines for parameter setting of micro-end-milling with hard material.展开更多
The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal tre...The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal treatment on mixed plastic waste using the mixture of polypropylene, polystyrene, polyethylene and polyvinyl chloride （PVC） has been performed to observe the dechlorination effect of hydrothermal treatment on the waste. The system was generally applying saturated steam at around 2.4 MPa in a stirring reactor for about 90 minutes. After undergoing the process, the organic chlorine in treated plastic waste was reduced to 1,700 ppm level while the inorganic chlorine content was increased, suggesting an organic chlorine conversion phenomenon to inorganic chlorine, accompanied with low pH due to dehydrochlorination process. Additional limestone （Ca（OH）2） in subsequent experiment showed that the similar phenomenon was occurred but with higher pH and lower chlorine content in the condensed water, suggesting the production of inorganic salt rather than hydrochloric acid. Laboratory scale experiment was also performed to confirm the dechlorination phenomena especially for PVC, and the result showed that the main parameter which affected the dechlorination phenomena was the amount of water in hydrothermal process rather than limestone addition. It is suggested that a combination ofhydrothermal process and alkali addition would produce a low-chlorine solid product from plastic waste, promoting its usage as alternative solid fuel.展开更多
The main research purpose of this paper is to study the mechanical properties of the sand gravel packing of the retaining wall under the creep condition of reinforced materials, in order to figure it out, Indoor physi...The main research purpose of this paper is to study the mechanical properties of the sand gravel packing of the retaining wall under the creep condition of reinforced materials, in order to figure it out, Indoor physical experiments were carried out.展开更多
Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid t...Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid tied to a skeletal frame. The three patterns of slice reinforcement were used to reinforce cementitious slabs with or without conventional wire mesh reinforcement. The slabs were square and simply supported at their periphery with a clear span of 400 mm, and concentrically patch loaded to failure. For specimens designed to fail in flexure, the specimens reinforced with CFRP slices showed a smoother load deflection response and higher flexural capacity. For slabs designed to fail in punching shear, adding CFRP slices showed significant improvement in the ultimate shear capacity and ductility over reference specimens. Well distributed fine cracks of smaller width than control specimens were developed and no matrix spalling was observed.展开更多
Bone protein extract is regarded as the new generation of demineralized bone matrix. The aim of this paper is to describe and characterize the properties of demineralized bone matrix and its new generation product in ...Bone protein extract is regarded as the new generation of demineralized bone matrix. The aim of this paper is to describe and characterize the properties of demineralized bone matrix and its new generation product in addition to its application in animal and human studies. Bone protein extract has features of osteoconductivity, osteoinductivity and osteogenicity, which originate from its unique and precise processing. It has exhibited powerful bone formation capacity both in animal experiments and in clinical trials by providing an optimal microenvironment for osteogenesis. Furthermore, not only does it have excellent bio- compatibility, it also has good compatibility with other implant materials, helping it bridge the host and implanted materials. Bone protein extract could be a promising alternative for demineralized bone matrix as a bone graft substitute.展开更多
文摘The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut hard metals. In this study, preliminary design of experiment （DOE） test program was conducted to investigate and i- dentify the factors affecting tool wear at the micro-scale with hard material. Analysis of variance （ANOVA） and Taguchi method were efficient to determine appropriate cutting condition and the effect of parameters. A simple model was also developed to predict the width of slots on the workpiece along the cutting length. The obtained re- suits can provide the basic guidelines for parameter setting of micro-end-milling with hard material.
文摘The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal treatment on mixed plastic waste using the mixture of polypropylene, polystyrene, polyethylene and polyvinyl chloride （PVC） has been performed to observe the dechlorination effect of hydrothermal treatment on the waste. The system was generally applying saturated steam at around 2.4 MPa in a stirring reactor for about 90 minutes. After undergoing the process, the organic chlorine in treated plastic waste was reduced to 1,700 ppm level while the inorganic chlorine content was increased, suggesting an organic chlorine conversion phenomenon to inorganic chlorine, accompanied with low pH due to dehydrochlorination process. Additional limestone （Ca（OH）2） in subsequent experiment showed that the similar phenomenon was occurred but with higher pH and lower chlorine content in the condensed water, suggesting the production of inorganic salt rather than hydrochloric acid. Laboratory scale experiment was also performed to confirm the dechlorination phenomena especially for PVC, and the result showed that the main parameter which affected the dechlorination phenomena was the amount of water in hydrothermal process rather than limestone addition. It is suggested that a combination ofhydrothermal process and alkali addition would produce a low-chlorine solid product from plastic waste, promoting its usage as alternative solid fuel.
文摘The main research purpose of this paper is to study the mechanical properties of the sand gravel packing of the retaining wall under the creep condition of reinforced materials, in order to figure it out, Indoor physical experiments were carried out.
文摘Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid tied to a skeletal frame. The three patterns of slice reinforcement were used to reinforce cementitious slabs with or without conventional wire mesh reinforcement. The slabs were square and simply supported at their periphery with a clear span of 400 mm, and concentrically patch loaded to failure. For specimens designed to fail in flexure, the specimens reinforced with CFRP slices showed a smoother load deflection response and higher flexural capacity. For slabs designed to fail in punching shear, adding CFRP slices showed significant improvement in the ultimate shear capacity and ductility over reference specimens. Well distributed fine cracks of smaller width than control specimens were developed and no matrix spalling was observed.
基金supported by the National Basic Research Program of China (Grant No. 2012CB619105)the National Natural Science Foundation of China (Grant Nos. 30571892, 81071512 and u0732001)the Fabrikant Mads Clausens Foundation of Denmark
文摘Bone protein extract is regarded as the new generation of demineralized bone matrix. The aim of this paper is to describe and characterize the properties of demineralized bone matrix and its new generation product in addition to its application in animal and human studies. Bone protein extract has features of osteoconductivity, osteoinductivity and osteogenicity, which originate from its unique and precise processing. It has exhibited powerful bone formation capacity both in animal experiments and in clinical trials by providing an optimal microenvironment for osteogenesis. Furthermore, not only does it have excellent bio- compatibility, it also has good compatibility with other implant materials, helping it bridge the host and implanted materials. Bone protein extract could be a promising alternative for demineralized bone matrix as a bone graft substitute.
