The most significant differences between continuous welded rails （CWRs） and general split-type connectors are axial compression in the longitudinal direction, buckling stability and other issues generated under the ...The most significant differences between continuous welded rails （CWRs） and general split-type connectors are axial compression in the longitudinal direction, buckling stability and other issues generated under the influence of thermal effect. Under thermal effect, a dynamical behavior similar to that of a beam fixed on two sides occurs in the central locked area of the welded rail, as there is axial compression but no possibility of sliding. Continuous welded rails do not contract or expand, and are supported by the dynamical system made up of ballasts and rail clips. The rail-support system mentioned above has the features of non-uniform material distribution and uncertainty of construction quality. Due to these facts, the dynamics method based on the linear elastic hypothesis cannot correctly evaluate the rail＇s buckling conditions. This study is aimed at applying Finite Difference Method （FDM） and Monte Carlo Random Normal Variables Method to the analysis of welded rail＇s buckling behavior during the train＇s acceleration and deceleration, under thermal effect and uncertain factors of ballast and rail clips. The analysis result showed that buckling occurs under the combined effect of thermal effect and the train＇s deceleration force co-effect and the variance ratio of ballast and rail clips is over 0.85, or under the combined effect of thermal effect and the train＇s acceleration force when the ariance ratio is over 0.88.展开更多
This study is aimed to investigate and analyze the vegetation landscape around Rivers of Hou-lung, Fa-tz, Da-li, Ching-shuei and Gau- ping, and to select the suitable plant species that could be applied for the area o...This study is aimed to investigate and analyze the vegetation landscape around Rivers of Hou-lung, Fa-tz, Da-li, Ching-shuei and Gau- ping, and to select the suitable plant species that could be applied for the area of riverbank ecological engineering in Taiwan. Studying the vegetation established the key point and procedure of ecological engineering in the riverside and revetment, to compile and edit the dominant plants＇ types, life form, propagating method, root systems＇ characteristics and functions for soil conservation. This research choses three dominant plants for roots strength test. The fitting models of plants pulling resistance（Rp, kg） between plant height （H, cm）, diameter near ground （Dn, mm）, diameter above ground 100 mm （Da, mm）, The research finished the relative abundant, types and cluster analysis of riverbank dominant plants that generalize vegetative distribution and ecological restoration for different river types to apply and manage in Taiwan.展开更多
The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed b...The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially,the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell.展开更多
Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compres...Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compressive strength based on ACI (American Concrete Institute) code. Investigations of recent devastating collapses of structures around the world showed that some of the collapses directly resulted from the poor quality of the concrete. The lesson learned from these tragedies is that guaranteeing high quality of concrete is one of the most important factors ensuring the safety of the reinforced concrete structure. In order to ensure high quality of concrete, a new method for analyzing and evaluating the concrete production process is called for. In this paper, the indices of fit and stable degree are proposed as basis to evaluate the fitness and stability of concrete’s compressive strength. These two indices are combined to define and evaluate the quality index of the compressive strength of concrete. Prin-ciples of statistics are used to derive the best estimators of these indices. Based on the outcome of the study, a concrete compres-sive strength quality control chart is proposed as a tool to help the evaluation process. Finally, a new evaluation procedure to assess the quality control capability of the individual concrete manufacturer is also proposed.展开更多
Prestressed concrete structures are main conformati on for the construction of high way bridges. The quality of prestressed concrete s tructures is mainly affected by the tensile strength of prestressing strand. In or...Prestressed concrete structures are main conformati on for the construction of high way bridges. The quality of prestressed concrete s tructures is mainly affected by the tensile strength of prestressing strand. In order to attain the purpose of economic design and long life span of prestressin g strand, the less relaxation property of strand type is suitable for constructi on and usage. Thus, the research and development of prestressing strand is requi red to reach the goals of high tensile strength and low relaxation. To ensure th e required quality of prestressing strand, the strand pull test and long period relaxation test are two important items for the quality assurance. There are thr ee specific items of the tensile strength test are belong to larger-the-better quality type. The quality type of smaller-the-better is for the long period r elaxation test. However, many existing methods are able to measure process capab ility for product with single quality characteristic and cannot be applied to mo st products with multiple properties. Thus, the indices of C pu and C pl, for larger-the-better and smaller-the-better quality type respec tively proposed by Kane, are quoted and combined to propose a new index to evalu ate the quality of multiple characteristics of prestressing strand in this paper . Then, the principle of statistics is used to derive the one-to-one mathemati cal relationship of this new index and ratio of tallied. Finally, the procedure and criteria to evaluate the quality of prestressing strand is proposed. This in tegrated multi-quality property capability analysis model can be used to evalua te the multi-process capabilities and provide continuous improvement on manufac turing process of prestressing strand.展开更多
A new powdery mildew fungus named Erysiphe euonymicola was discovered in the mycobiota of Uzbekistan as a result of a mycological study conducted in the city of Samarkand. This fungus was found on the bush Euonymus ja...A new powdery mildew fungus named Erysiphe euonymicola was discovered in the mycobiota of Uzbekistan as a result of a mycological study conducted in the city of Samarkand. This fungus was found on the bush Euonymus japonicum and a brief description along with photographs of Erysiphe euonymicola have been provided. Erysiphe euonymicola is a phytopathogenic fungus that infects 80% - 90% of the leaves and young branches of Euonymus japonicum. The first symptoms of the disease are round, weeping spots on the leaves;later the spots form white mycelium over the entire surface of the leaves. When the plant is heavily infected, both sides of the leaves are completely covered with mycelium. The fungus Erysiphe euonymicola, parasitizing Euonymus japonicum, seriously inhibits the development of the host plant. The mycelium of Erysiphe euonymicola is formed on the surface of the leaf of the host plant and is a cluster of hyphae that form a dense covering in the form of a round spot. Conidiophores are erect, unbranched, and of Pseudoidium type, very variable in shape and size. Conidiophores consist of 2 - 3 cylindrical cells growing vertically from the hyphae;the sizes of conidiophores are given relative to the average length and width of selected conidiophores (n = 15). According to scanning electron microscopy, ellipsoidal-cylindrical conidia are single, scattered among conidiophores, ranging in size from 23.97 to 24.51 × 11.5 to 12.47 µm (n = 15). Conidial stalk cells are usually straight or slightly curved, ranging in size from 23.5 to 23.91 × 7.17 to 7.47 µm (n = 15).展开更多
As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis a...As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis and expert knowledge gathered within COST Action FP1204 GreenInUrbs,we proposed a classification of urban forest EESs into three categories:(A)regulation of air,water,soil and climate;(B)provisioning of habitat quality;and(C)provisioning of other goods and services.Each category is divided into EES types:(a)amelioration of air quality;restoration of soil and water;amelioration of the microclimate;removal of CO2 from the air;(b)provision of habitat for biodiversity;support for resilient urban ecosystems;provision of genetic diversity;and(c)provision of energy and nutrients;provision of grey infrastructure resilience.Each EES type provides one or more benefits.For each of these 12 benefits,we propose a set of indicators to be used when analyzing the impacts on the identified EESs.Around half of the 36 indicators are relevant to more than one single benefit,which highlights complex interrelationships.The indicators of wider applicability are tree and stand characteristics,followed by leaf physical traits and tree species composition.This knowledge is needed for the optimization of the EESs delivered by urban forests,now and in the future.展开更多
A passive energy-dissipating device, velocity, and displacement dependent hydraulic damper (VDHD), is developed to reduce the seismic response of structure. This device is comprised of a hydraulic jack, check valve, r...A passive energy-dissipating device, velocity, and displacement dependent hydraulic damper (VDHD), is developed to reduce the seismic response of structure. This device is comprised of a hydraulic jack, check valve, relief valve, and throttle valve. The numerical analysis model for SAP2000 nonlinear analysis program is proposed to simulate the energy-dissipating characteristics of VDHD. The analysis results of this model compared with the seismic resistant tests reveal that this proposed model can accurately describe the actual energy-dissipating behavior of VDHD. The efficiency of VDHD is confirmed using this proposed model for carrying out numerical analyses of bare building, building added with bulking resistant bracing (BBR), and VDHD. The energy-dissipating capabilities of VDHD are performing excellent displacement and acceleration control with various ground magnitudes; being an energy absorber to absorb mechanical energy in the structure and resist structural movement; and gathering the advantage of BRB.展开更多
Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were re...Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were remediated by means of Technosol engineering,when grasses were sown on the two different types of mining wastes (carbonatite and serpentinite-magnesite) covered by hydroponic vermiculite.The serpentinite-magnesite waste was significantly different from the carbonatite waste in the content of silicon (Si) and manganese (Mn),pH,and texture.Both wastes had an alkaline pH level and high content of calcium (Ca) and magnesium (Mg).The vegetation and Technosol properties at the remediated sites were analyzed in 2017 and compared to the initial state (2010 year) to assess the efficiency of the long-term remediation.The quality and sustainability of Technosols based on the serpentinite-magnesite wastes were substantially higher compared to the carbonatite-based Technosol.Biomass and a projective cover of the grass community depended on Si content in the original mining waste and were found to be higher in the serpentinite-magnesite Technosol.The content of organic carbon and its fractions,microbial biomass and basal respiration after seven years of Technosol evolution was comparable to natural values.These parameters were directly related to plant cover state and were inversely proportional to copper (Cu) content in Technosol.The Technosol development led to the reduction of nickel (Ni) and Cu migration in soil-plant ecosystems due to neutralization and adsorption properties of mining wastes and phytostabilization by underground parts of grass communities.The Technosol development in its early stage of pedogenesis indicates the efficiency of applied remediation technology to the degraded acidic soil under the conditions of industrial atmospheric pollution.展开更多
基金Project supported by the National Science Council of Taiwan (No.NSC 93-2211-E-167-002), China
文摘The most significant differences between continuous welded rails （CWRs） and general split-type connectors are axial compression in the longitudinal direction, buckling stability and other issues generated under the influence of thermal effect. Under thermal effect, a dynamical behavior similar to that of a beam fixed on two sides occurs in the central locked area of the welded rail, as there is axial compression but no possibility of sliding. Continuous welded rails do not contract or expand, and are supported by the dynamical system made up of ballasts and rail clips. The rail-support system mentioned above has the features of non-uniform material distribution and uncertainty of construction quality. Due to these facts, the dynamics method based on the linear elastic hypothesis cannot correctly evaluate the rail＇s buckling conditions. This study is aimed at applying Finite Difference Method （FDM） and Monte Carlo Random Normal Variables Method to the analysis of welded rail＇s buckling behavior during the train＇s acceleration and deceleration, under thermal effect and uncertain factors of ballast and rail clips. The analysis result showed that buckling occurs under the combined effect of thermal effect and the train＇s deceleration force co-effect and the variance ratio of ballast and rail clips is over 0.85, or under the combined effect of thermal effect and the train＇s acceleration force when the ariance ratio is over 0.88.
基金Taiwan Science Council Research Project (94- 2313-B-235-001)
文摘This study is aimed to investigate and analyze the vegetation landscape around Rivers of Hou-lung, Fa-tz, Da-li, Ching-shuei and Gau- ping, and to select the suitable plant species that could be applied for the area of riverbank ecological engineering in Taiwan. Studying the vegetation established the key point and procedure of ecological engineering in the riverside and revetment, to compile and edit the dominant plants＇ types, life form, propagating method, root systems＇ characteristics and functions for soil conservation. This research choses three dominant plants for roots strength test. The fitting models of plants pulling resistance（Rp, kg） between plant height （H, cm）, diameter near ground （Dn, mm）, diameter above ground 100 mm （Da, mm）, The research finished the relative abundant, types and cluster analysis of riverbank dominant plants that generalize vegetative distribution and ecological restoration for different river types to apply and manage in Taiwan.
基金Project (No. NSC-95-2221-E-167-002) supported by the National Science Council of Taiwan, China
文摘The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially,the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell.
基金Project (No. NSC92-2213-e-167-001) supported by the National Science Council, Taiwan, China
文摘Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compressive strength based on ACI (American Concrete Institute) code. Investigations of recent devastating collapses of structures around the world showed that some of the collapses directly resulted from the poor quality of the concrete. The lesson learned from these tragedies is that guaranteeing high quality of concrete is one of the most important factors ensuring the safety of the reinforced concrete structure. In order to ensure high quality of concrete, a new method for analyzing and evaluating the concrete production process is called for. In this paper, the indices of fit and stable degree are proposed as basis to evaluate the fitness and stability of concrete’s compressive strength. These two indices are combined to define and evaluate the quality index of the compressive strength of concrete. Prin-ciples of statistics are used to derive the best estimators of these indices. Based on the outcome of the study, a concrete compres-sive strength quality control chart is proposed as a tool to help the evaluation process. Finally, a new evaluation procedure to assess the quality control capability of the individual concrete manufacturer is also proposed.
文摘Prestressed concrete structures are main conformati on for the construction of high way bridges. The quality of prestressed concrete s tructures is mainly affected by the tensile strength of prestressing strand. In order to attain the purpose of economic design and long life span of prestressin g strand, the less relaxation property of strand type is suitable for constructi on and usage. Thus, the research and development of prestressing strand is requi red to reach the goals of high tensile strength and low relaxation. To ensure th e required quality of prestressing strand, the strand pull test and long period relaxation test are two important items for the quality assurance. There are thr ee specific items of the tensile strength test are belong to larger-the-better quality type. The quality type of smaller-the-better is for the long period r elaxation test. However, many existing methods are able to measure process capab ility for product with single quality characteristic and cannot be applied to mo st products with multiple properties. Thus, the indices of C pu and C pl, for larger-the-better and smaller-the-better quality type respec tively proposed by Kane, are quoted and combined to propose a new index to evalu ate the quality of multiple characteristics of prestressing strand in this paper . Then, the principle of statistics is used to derive the one-to-one mathemati cal relationship of this new index and ratio of tallied. Finally, the procedure and criteria to evaluate the quality of prestressing strand is proposed. This in tegrated multi-quality property capability analysis model can be used to evalua te the multi-process capabilities and provide continuous improvement on manufac turing process of prestressing strand.
文摘A new powdery mildew fungus named Erysiphe euonymicola was discovered in the mycobiota of Uzbekistan as a result of a mycological study conducted in the city of Samarkand. This fungus was found on the bush Euonymus japonicum and a brief description along with photographs of Erysiphe euonymicola have been provided. Erysiphe euonymicola is a phytopathogenic fungus that infects 80% - 90% of the leaves and young branches of Euonymus japonicum. The first symptoms of the disease are round, weeping spots on the leaves;later the spots form white mycelium over the entire surface of the leaves. When the plant is heavily infected, both sides of the leaves are completely covered with mycelium. The fungus Erysiphe euonymicola, parasitizing Euonymus japonicum, seriously inhibits the development of the host plant. The mycelium of Erysiphe euonymicola is formed on the surface of the leaf of the host plant and is a cluster of hyphae that form a dense covering in the form of a round spot. Conidiophores are erect, unbranched, and of Pseudoidium type, very variable in shape and size. Conidiophores consist of 2 - 3 cylindrical cells growing vertically from the hyphae;the sizes of conidiophores are given relative to the average length and width of selected conidiophores (n = 15). According to scanning electron microscopy, ellipsoidal-cylindrical conidia are single, scattered among conidiophores, ranging in size from 23.97 to 24.51 × 11.5 to 12.47 µm (n = 15). Conidial stalk cells are usually straight or slightly curved, ranging in size from 23.5 to 23.91 × 7.17 to 7.47 µm (n = 15).
基金financially supported by COST Action FP1204 GreenInUrbsPRIN project EUFORICCMinistry of Education and Science of the Russian Federation(the Agreement No.02.A03.21.0008)
文摘As a Nature-Based Solution,urban forests deliver a number of environmental ecosystem services(EESs).To quantify these EESs,well-defined,reliable,quantifiable and stable indicators are needed.With literature analysis and expert knowledge gathered within COST Action FP1204 GreenInUrbs,we proposed a classification of urban forest EESs into three categories:(A)regulation of air,water,soil and climate;(B)provisioning of habitat quality;and(C)provisioning of other goods and services.Each category is divided into EES types:(a)amelioration of air quality;restoration of soil and water;amelioration of the microclimate;removal of CO2 from the air;(b)provision of habitat for biodiversity;support for resilient urban ecosystems;provision of genetic diversity;and(c)provision of energy and nutrients;provision of grey infrastructure resilience.Each EES type provides one or more benefits.For each of these 12 benefits,we propose a set of indicators to be used when analyzing the impacts on the identified EESs.Around half of the 36 indicators are relevant to more than one single benefit,which highlights complex interrelationships.The indicators of wider applicability are tree and stand characteristics,followed by leaf physical traits and tree species composition.This knowledge is needed for the optimization of the EESs delivered by urban forests,now and in the future.
基金the Science Council of Taiwan, Chinese Taipei (No. NSC-96-2625-Z-167-001)
文摘A passive energy-dissipating device, velocity, and displacement dependent hydraulic damper (VDHD), is developed to reduce the seismic response of structure. This device is comprised of a hydraulic jack, check valve, relief valve, and throttle valve. The numerical analysis model for SAP2000 nonlinear analysis program is proposed to simulate the energy-dissipating characteristics of VDHD. The analysis results of this model compared with the seismic resistant tests reveal that this proposed model can accurately describe the actual energy-dissipating behavior of VDHD. The efficiency of VDHD is confirmed using this proposed model for carrying out numerical analyses of bare building, building added with bulking resistant bracing (BBR), and VDHD. The energy-dissipating capabilities of VDHD are performing excellent displacement and acceleration control with various ground magnitudes; being an energy absorber to absorb mechanical energy in the structure and resist structural movement; and gathering the advantage of BRB.
基金the Russian Foundation for Basic Research Project 16-35-60022Analysis of C quantity and quality was supported by the Russian Science Foundation Project 17-77-20046Data analysis and processing were supported by the RUDN University“5-100”Project.
文摘Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were remediated by means of Technosol engineering,when grasses were sown on the two different types of mining wastes (carbonatite and serpentinite-magnesite) covered by hydroponic vermiculite.The serpentinite-magnesite waste was significantly different from the carbonatite waste in the content of silicon (Si) and manganese (Mn),pH,and texture.Both wastes had an alkaline pH level and high content of calcium (Ca) and magnesium (Mg).The vegetation and Technosol properties at the remediated sites were analyzed in 2017 and compared to the initial state (2010 year) to assess the efficiency of the long-term remediation.The quality and sustainability of Technosols based on the serpentinite-magnesite wastes were substantially higher compared to the carbonatite-based Technosol.Biomass and a projective cover of the grass community depended on Si content in the original mining waste and were found to be higher in the serpentinite-magnesite Technosol.The content of organic carbon and its fractions,microbial biomass and basal respiration after seven years of Technosol evolution was comparable to natural values.These parameters were directly related to plant cover state and were inversely proportional to copper (Cu) content in Technosol.The Technosol development led to the reduction of nickel (Ni) and Cu migration in soil-plant ecosystems due to neutralization and adsorption properties of mining wastes and phytostabilization by underground parts of grass communities.The Technosol development in its early stage of pedogenesis indicates the efficiency of applied remediation technology to the degraded acidic soil under the conditions of industrial atmospheric pollution.
