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Experimental Investigation of Capacity Control Scheme on System Performance for a Machine Tool Cooler

Chinese Journal of Mechanical Engineering 2011年第3期24卷 333-339页

作者： WANG Fujen chang Tongbou KAO Jianwei lee Haochung Department of Refrigeration Air Conditioning and Energy Engineering Chin-Yi University of Technology Taiehung 411 Taiwan China Department of Mechanical Engineering Southern Taiwan University Tainan 710 Taiwan China Energy and Environment Research Laboratories Industrial Technology Research Institute Hsinchu 310 Taiwan China

Highly accurate manufacture in machining industry can only be obtained with precise temperature control of the coolant （oil or water）.Machine tool with more accurate,stable and advanced the precision of the working component cannot be developed without appropriate ***,the machine tool coolers are facing the control hunting of cooling temperature and the dramatic variation of heat load in high-accuracy *** main objective of this study is to evaluate the influence of the hot-gas by-pass scheme and suction regulation for capacity control of a machine tool cooler *** this study,experimental investigation on both hot-gas by-pass scheme and suction valve regulation for capacity control has been *** of using capillary tube and thermostatic expansion valve along with different capacity control scheme have been investigated extensively in an environmental testing *** performance and power consumption of the cooler system have been measured and analyzed as well by comparing with different opening percentage of throttling valve under specific coolant *** experimental results reveal that the power consumption will reduce slightly by capacity control using the hot-gas by-pass scheme but the coefficient of performance （COP） of the overall system will *** coolant temperature will result in higher compressor power consumption as *** conducting suction valve regulating for capacity control,energy-saving at 10%-12% can be obtained by using thermostatic expansion valve under different evaporator *** also reveals that suction valve regulation along with adequate choice of thermostatic expansion valve can provide alternative choice for steady capacity control and substantial *** proposed cooler systems with different capacity control schemes are not only more cost-effective than inverter driven system,but also can perform energy-saving and precise temperature control specific for high-accur

关键词： machine tool cooler hot-gas by-pas suction regulation capacity control

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Structural stability estimation of whirling unit

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中国有色金属学会会刊：英文版 2009年第B09期19卷 202-208页

作者： Son-Jae HWAN Han-chang WOO lee-Sang RYONG lee-Young MOON Daegu Machinery Institute of Component & Materials Foundation Department of Automobile Yeungnam College of Science & Technology Department of Mechanical Engineering Kyung pook National University

Whirling is a cutting process in which a series of cutting edges on whirling ring remove material by turning over a rotating workpiece. In this study static and dynamic stability of whirling unit was estimated by using ADAMS and NASTRAN softwares. Each maximum force acting on the bearing attached to the spindle assembly and the cutting tool attached to the whirling ring with the rotating speed of 6 000 r/min was 235 N and 902 N respectively. The maximum stress of 0.74 MPa on the base frame is far smaller than the yield strength of 282 MPa. The calculated natural frequency of 148 Hz of the system is far from the frequency of the driving speed of 6 000 r/min. The experimentally obtained maximum cutting force of 792 N is smaller than that of calculated value. And the experimentally obtained natural frequency of 118 Hz is beyond the driving speed of 6000 r/min. From above results it can be judged that the whirling system is statically and dynamically stable.

关键词：旋转工件稳定性评价 NASTRAN软件动态稳定性结构单元固有频率行车速度

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Microstructure of fast tool servo machining on copper alloy

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中国有色金属学会会刊：英文版 2012年第S3期22卷 820-824页

作者： Hong LU Soo-chang CHOI Sang-min lee Deug-woo lee Department of Nano Fusion Technology Pusan National University Korea Institute of Machinery & Materials Department of Nano Mechatronics Engineering Pusan National University

The development of the fast tool servo (FTS) for precision machining was *** micron machining performance of a piezoelectric-assisted FTS on copper alloy was *** results indicate that the quality of the microstructure depends mainly on two important factors:the cutting speed (or spindle speed) and the driving frequency of the *** excessive driving frequency increases the formation of *** effect of the clearance angle of the diamond tool on the microstructure machining precision was also investigated.

关键词： fast tool servo microstructure piezoelectric diamond machining copper alloy

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Dextran sulfate sodium-induced colitis-associated neoplasia:a promising model for the development of chemopreventive interventions

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Acta Pharmacologica Sinica 2007年第9期28卷 1450-1459页

作者： Margie lee CLAPPER Harry Stanley COOPER Wen-Chi lee chang Divisions of Population Science Medical Science Fox Chase Cancer CenterPhiladelphiaPA 19111USA

Individuals diagnosed with ulcerative colitis face a significantly increased risk ofdeveloping colorectal dysplasia and cancer during their *** date,littleattention has been given to the development of a chemopreventive interventionfor this high-risk *** mouse model of dextran sulfate sodium (DSS)-induced colitis represents an excellent preclinical system in which to both charac-terize the molecular events required for tumor formation in the presence of inflam-mation and assess the ability of select agents to inhibit this *** admin-istration of DSS in drinking water results in the establishment of chronic colitisand the development of colorectal dysplasias and cancers with pathological fea-tures that resemble those of human colitis-associated *** incidenceand multiplicity of lesions observed varies depending on the mouse strain used(ie,Swiss Webster,C57BL/6J,CBA,ICR) and the dose (0.7%-5.0%) and schedule(1-15 cycles with or without a subsequent recovery period) of *** incidenceof neoplasia can be increased and its progression to invasive cancer acceleratedsignificantly by administering DSS in combination with a known colon carcinogen(azoxymethane (AOM),2-amino-3-methylimidazo[4,5-f]quinoline (IQ),2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)) or *** recent induction ofcolitis-associated neoplasia in genetically defined mouse strains has providednew insight into the role of specific genes (ie,adenomatous polyposis coli (Apc),p53,inducible nitric oxide synthase (iNOS),Msh2) in the development of colitis-associated *** data from chemopreventive intervention studiesdocument the efficacy of several agents in inhibiting DSS-induced neoplasiaand provide great promise that colitis-associated colorectal neoplasia is a pre-ventable disease.

关键词： colorectal colitis chemoprevention dextran sulfate sodium mouse models

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Should anticoagulants be administered for portal vein thrombosis associated with acute pancreatitis?

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World Journal of Gastroenterology 2012年第42期18卷 6168-6171页

作者： Won-Seok Park hyeong-Il Kim Byung-Jun Jeon Seong-Hun Kim SeungOk lee Division of Gastroenterology Department of Internal MedicineDaejeon St.Mary's HospitalThe Catholic University of KoreaDaejeon 301-723South Korea Division of Gastroenterology Department of Internal MedicineChonbuk National University College of MedicineJeonju 561-712South Korea

Venous complications in patients with acute pancreatitis typically occur as a form of splenic,portal,or superior mesenteric vein thrombosis and have been detected more frequently in recent *** a well-organized protocol for the treatment of venous thrombosis has not been established,anticoagulation therapy is commonly recommended.A 73-year-old man was diagnosed with acute progressive portal vein thrombosis associated with acute *** one month of anticoagulation therapy,the patient developed severe *** endoscopy and an abdominal computed tomography scan,hemorrhages in the pancreatic pseudocyst,which was ruptured into the duodenal bulb,were *** conservative treatment,the patient was *** the rupture of a pseudocyst into the surrounding viscera is a well-known phenomenon,spontaneous rupture into the duodenum is ***,no reports of upper gastrointestinal bleeding caused by pseudocyst rupture in patients under anticoagulation therapy for venous thrombosis associated with acute pancreatitis have been ***,we report a unique case of massive upper gastrointestinal bleeding due to pancreatic pseudocyst rupture into the duodenum,which developed during anticoagulation therapy for portal vein thrombosis associated with acute pancreatitis.

关键词： Pancreatitis Pancreatic pseudocyst Portal vein Venous thrombosis Warfarin

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Detection of thinned corticospinal tract and corticoreticular pathway in a patient with a calf circumference discrepancy

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Neural Regeneration Research 2018年第2期13卷 366-368页

作者： han do lee min cheol chang department of physical medicine and rehabilitation college of medicineyeungnam university

In clinical practice, it is challenging to elucidate the location of the lesion in a patient＇s nervous system that is causing the neurologic symptoms, because lesions are often microscopic and cannot be revealed by c... 详细信息

关键词： Detection of thinned corticospinal tract and corticoreticular pathway in a patient with a calf circumference discrepancy CRP CST

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Comparative study on discharge conditions in micro-hole electrical discharge machining of tungsten carbide (WC-Co) material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 114-118页

作者： Hyun-Seok TAK chang-Seung HA Dong-Hyun KIM Ho-Jun lee Hae-June lee Myung-chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

WC-Co is used widely in die and mold industries due to its unique combination of hardness, strength and wear-resistance. For machining difficult-to-cut materials, such as tungsten carbide, micro-electrical discharge machining(EDM) is one of the most effective methods for making holes because the hardness is not a dominant parameter in EDM. This paper describes the characteristics of the discharge conditions for micro-hole EDM of tungsten carbide with a WC grain size of 0.5 μm and Co content of 12%. The EDM process was conducted by varying the condenser and resistance values. A R-C discharge EDM device using arc erosion for micro-hole machining was suggested. Furthermore, the characteristics of the developed micro-EDM were analyzed in terms of the electro-optical observation using an oscilloscope and field emission scanning electron microscope.

关键词：电火花加工碳化钨钴难切削材料硬质合金放电扫描电子显微镜微孔模具行业

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Fatigue severity of patients with idiopathic chronic fatigue compared to healthy subjects

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Journal of Traditional Chinese Medicine 2012年第3期32卷 355-357页

作者： Nam Hun lee chang Gue Son Liver and Immunology Research Center Daejeon Oriental Hospital of Daejeon University

OBJECTIVE:To analyze the fatigue severity of patients with idiopathic chronic fatigue(ICF) and to compare the severity of this group with that of healthy ***:one hundred and nine ICF patients and 98 healthy subjects were enrolled in this *** severity was measured using the Korean-translated Chalder fatigue severity *** subjects scored each item on a 10-point scale as a self-rating numeric scale(NRS),and additionally rated their feeling of general fatigue by visual analogue scale(VAS).RESULTS:The total NRS scores of patients with ICF was 53 ± 15 compared with 25 ± 14 of healthy subjects(2.4 folds for physical symptoms vs.1.7 folds for mental symptoms respectively).The VAS scores of patients with ICF were 2.7 times as high as those of healthy ***:This report is the first to compare the severity of fatigue between ICF patients and healthy *** study contains reference data applicable for the management of this disorder in field of complementary and alternative medicine.

关键词： Fatigue syndrome,chronic Pain measurement Quality of life

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Characteristic evaluation of Al_2O_3/CNTs hybrid materials for micro-electrical discharge machining

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 28-32页

作者： Hyun-Seok TAK chang-Seung HA Ho-Jun lee Hyung-Woo lee Young-Keun JEONG Myung-chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

The characteristic evaluation of aluminum oxide （A1203）/carbon nanotubes （CNTs） hybrid composites for micro-electrical discharge machining （EDM） was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. A1203 composites with different CNT concentrations were synthesized. The electrical characteristic of A1203/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope （FESEM）. The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% A1203 （volume fraction）. In the machining accuracy, many tangles of CNT in A1203/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of A1203/CNTs hybrid composites.

关键词： A1203/CNTs hybrid materials micro-electrical discharge machining micro-hole electrical conductivity

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Recent advances in soft electronic materials for intrinsically stretchable optoelectronic systems

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Opto-Electronic Advances 2022年第8期5卷 21-49页

作者： Ja Hoon Koo Huiwon Yun Woongchan lee Sung-Hyuk Sunwoo Hyung Joon Shim Dae-hyeong Kim Center for Nanoparticle Research Institute for Basic Science(IBS)Seoul 08826Republic of Korea School of Chemical and Biological Engineering Institute of Chemical ProcessesSeoul National UniversitySeoul 08826Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea.

In recent years,significant progress has been achieved in the design and fabrication of stretchable optoelectronic *** general,stretchability has been achieved through geometrical modifications of device components,such as with serpentine interconnects or buckled ***,the local stiffness of individual pixels and the limited pixel density of the array have impeded further advancements in stretchable ***,intrinsically stretch-able optoelectronics have been proposed as an alternative ***,we review the recent advances in soft elec-tronic materials for application in intrinsically stretchable optoelectronic ***,we introduce various intrinsically stretchable electronic materials,comprised of electronic fillers,elastomers,and surfactants,and exemplify different in-trinsically stretchable conducting and semiconducting *** also describe the processing methods used to fabricate the electrodes,interconnections,charge transport layers,and optically active layers used in intrinsically stretch-able optoelectronic ***,we review representative examples of intrinsically stretchable optoelectronic devices,including light-emitting capacitors,light-emitting diodes,photodetectors,and ***,we briefly discuss intrinsically stretchable integrated optoelectronic systems.

关键词： stretchable optoelectronics light-emitting capacitors light-emitting diodes photodetectors photovoltaics intrinsically stretchable devices

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