To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.A...To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.An automatic variable preload device was fabricated using an eccentric mass.By installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was analyzed.In the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/min.And,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,respectively.Based on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed.展开更多
Dysphagia is a common symptom that is important to recognise and appropriately manage, given that causes include life threatening oesophageal neoplasia, oropharyngeal dysfunction, the risk of aspiration, as well as ch...Dysphagia is a common symptom that is important to recognise and appropriately manage, given that causes include life threatening oesophageal neoplasia, oropharyngeal dysfunction, the risk of aspiration, as well as chronic disabling gastroesophageal reflux(GORD). The predominant causes of dysphagia varies between cohorts depending on the interplay between genetic predisposition and environmental risk factors, and is changing with time. Currently in white Caucasian societies adopting a western lifestyle, obesity is common and thus associated gastroesophageal reflux disease is increasingly diagnosed. Similarly, food allergies are increasing in the west, and eosinophilic oesophagitis is increasingly found as a cause. Other regions where cigarette smoking is still prevalent, or where access to medical care and antisecretory agents such as proton pump inhibitors are less available, benign oesophageal peptic strictures, Barrett's oesophagus, adeno-as well as squamous cell carcinoma are endemic. The evaluation should consider the severity of symptoms, as well as the pretest probability of a given condition. In young white Caucasian males who are atopic or describe heartburn, eosinophilic esophagitis and gastroesophageal reflux disease will predominate and a proton pump inhibitor could be commenced prior to further investigation. Upper gastrointestinal endoscopy remains a valid first line investigation for patients with suspected oesophageal dysphagia. Barium swallow is particularly useful for oropharyngeal dysphagia, and oesophageal manometry mandatory to diagnose motility disorders.展开更多
Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing syste...Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.展开更多
This article is focused on the fashion that inspired by corset and create a collection of the same kind that can reflect the needs of today＇ s consumers. In mixing and matching today＇ s a past corset＇ s elements wi...This article is focused on the fashion that inspired by corset and create a collection of the same kind that can reflect the needs of today＇ s consumers. In mixing and matching today＇ s a past corset＇ s elements with today＇ s sportive fashion.Since nowadays, people＇ s lifestyle is freer, casual and personal than before. Consumer＇ s wearing concept was also definitely different from the past.It is necessary to create the new direction for today＇ s consumers to satisfy the new mode of their lifestyle and the change of their wearing concept.展开更多
Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand cu...Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.展开更多
This paperdescribes the development and applications of a fiber-optic electric current sensing technique with the stable properties and compact, simple, and flexible structure of the sensing device. The special charac...This paperdescribes the development and applications of a fiber-optic electric current sensing technique with the stable properties and compact, simple, and flexible structure of the sensing device. The special characteristics of the sensors were achieved by use of the special low birefringence fiber as the Faraday-effect sensing element and were also achieved with creation of sensing schemes which matched with the features of the fiber. Making use of the excellent features of the sensing technique, various current monitoring devices and systems were developed and applied practically for the control and maintenance in the electric power facility. In this paper, the design and performance of the sensing devices are introduced first. After that, examples of the application systems practically applied are also introduced, including fault section/point location systems for power transmission cable lines.展开更多
Force closure and stability problems exist in heavy gripping devices.Based on a typical gripping device for forging operations, the workpiece and the gripping device are innovatively considered as a single mechanism i...Force closure and stability problems exist in heavy gripping devices.Based on a typical gripping device for forging operations, the workpiece and the gripping device are innovatively considered as a single mechanism in this paper,and its global topological configuration is obtained.The changing element method is used to establish the optimized topology geometry of the gripping device by decreasing the degrees of freedom of the gripping mechanism and improving the force closure performance. Therefore,a new idea for the innovative design of heavy-duty forging gripping devices is provided.As the effect of revolute joint friction on loading capacity of the gripping device cannot be ignored,a unified mechanical equation including friction in terms of the topological adjacency matrix is established to analyze the force closure performance and calculate the loading capacity.The conclusions are provided by experiments.展开更多
This paper discusses stress intensity factor （SIF） calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and re...This paper discusses stress intensity factor （SIF） calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and relative crack depths, a/D, ranging from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent SIF method, F＊EQ, was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison was then carried out with the combined SIF, F＊FE, obtained using the finite element analysis （FEA） under similar loadings. It was found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the results determined from the different approaches occurred when Fm was involved. It was also noted that the predicted F＊ EE using FEA was higher than the F＊EQ predicted through the equivalent SIF method due to the difference in crack face interactions.展开更多
基金Project(2011-0027035) supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF)funded by the Ministry of Education,Science and Technology,Korea
文摘To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.An automatic variable preload device was fabricated using an eccentric mass.By installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was analyzed.In the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/min.And,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,respectively.Based on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed.
文摘Dysphagia is a common symptom that is important to recognise and appropriately manage, given that causes include life threatening oesophageal neoplasia, oropharyngeal dysfunction, the risk of aspiration, as well as chronic disabling gastroesophageal reflux(GORD). The predominant causes of dysphagia varies between cohorts depending on the interplay between genetic predisposition and environmental risk factors, and is changing with time. Currently in white Caucasian societies adopting a western lifestyle, obesity is common and thus associated gastroesophageal reflux disease is increasingly diagnosed. Similarly, food allergies are increasing in the west, and eosinophilic oesophagitis is increasingly found as a cause. Other regions where cigarette smoking is still prevalent, or where access to medical care and antisecretory agents such as proton pump inhibitors are less available, benign oesophageal peptic strictures, Barrett's oesophagus, adeno-as well as squamous cell carcinoma are endemic. The evaluation should consider the severity of symptoms, as well as the pretest probability of a given condition. In young white Caucasian males who are atopic or describe heartburn, eosinophilic esophagitis and gastroesophageal reflux disease will predominate and a proton pump inhibitor could be commenced prior to further investigation. Upper gastrointestinal endoscopy remains a valid first line investigation for patients with suspected oesophageal dysphagia. Barium swallow is particularly useful for oropharyngeal dysphagia, and oesophageal manometry mandatory to diagnose motility disorders.
文摘Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.
文摘This article is focused on the fashion that inspired by corset and create a collection of the same kind that can reflect the needs of today＇ s consumers. In mixing and matching today＇ s a past corset＇ s elements with today＇ s sportive fashion.Since nowadays, people＇ s lifestyle is freer, casual and personal than before. Consumer＇ s wearing concept was also definitely different from the past.It is necessary to create the new direction for today＇ s consumers to satisfy the new mode of their lifestyle and the change of their wearing concept.
文摘Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country＇s borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases.
文摘This paperdescribes the development and applications of a fiber-optic electric current sensing technique with the stable properties and compact, simple, and flexible structure of the sensing device. The special characteristics of the sensors were achieved by use of the special low birefringence fiber as the Faraday-effect sensing element and were also achieved with creation of sensing schemes which matched with the features of the fiber. Making use of the excellent features of the sensing technique, various current monitoring devices and systems were developed and applied practically for the control and maintenance in the electric power facility. In this paper, the design and performance of the sensing devices are introduced first. After that, examples of the application systems practically applied are also introduced, including fault section/point location systems for power transmission cable lines.
文摘Force closure and stability problems exist in heavy gripping devices.Based on a typical gripping device for forging operations, the workpiece and the gripping device are innovatively considered as a single mechanism in this paper,and its global topological configuration is obtained.The changing element method is used to establish the optimized topology geometry of the gripping device by decreasing the degrees of freedom of the gripping mechanism and improving the force closure performance. Therefore,a new idea for the innovative design of heavy-duty forging gripping devices is provided.As the effect of revolute joint friction on loading capacity of the gripping device cannot be ignored,a unified mechanical equation including friction in terms of the topological adjacency matrix is established to analyze the force closure performance and calculate the loading capacity.The conclusions are provided by experiments.
文摘This paper discusses stress intensity factor （SIF） calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and relative crack depths, a/D, ranging from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent SIF method, F＊EQ, was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison was then carried out with the combined SIF, F＊FE, obtained using the finite element analysis （FEA） under similar loadings. It was found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the results determined from the different approaches occurred when Fm was involved. It was also noted that the predicted F＊ EE using FEA was higher than the F＊EQ predicted through the equivalent SIF method due to the difference in crack face interactions.
