An investigation on the in siㆍtu measurement of the oil - concentration

Chang-Nyeun Kim,Young-Moo Park 대한설비공학회 2001 International Journal Of Air-Conditioning and Refr Vol.9 No.1

In order to predict thermodynamic peformance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows.<br/> C=a+b×t+c×t²+(d+e×t+f×t²)×SG<br/> C is oil concentration, t is temperature(℃), SG is specific gravity of mixture and a~f is coefficients. The oil concentration ranges over 0~12 wt% and the temperature ranges over 20~50℃. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/POE oil liquid mixtures.

Investigation of Vapor - Liquid Equilibrium of HFC - 32 / 143a and HFC - 143a / 134a System

Chang Nyeun Kim,Young Moo Park 대한설비공학회 2000 International Journal Of Air-Conditioning and Refr Vol.8 No.2

Vapor-liquid equilibrium apparatus is designed and set up. The equilibrium data of two binary systems, HFC32/143a and HFC143a/134a, are measured. Fifteen equilibrium data for HFC32/143a and HFC143a/134a systems are measured over the temperature range 263.15~283.15K at 10K interval and the composition range 0.10~0.80, respectively.<br/> And vapor-liquid equilibrium data are calculated using equation of state and correlation of activity coefficient and compared with the present data. Equation of state is CSD and RKS equations and correlation of activity coefficient is Margules' and Van Ness and Abbott's correlations.<br/> Real behavior of HFC32/143a system has very large deviation from Raoult's rule which is ideal behavior. But real behavior of HFC143a/134a system is similar to ideal behavior.<br/> The calculated data from CSD equation are compared with the data in the open literatures and the calculated data from REFPROP. Compared with REFPROP, the relative deviations of bubble point pressure for HFC32/143a system are within -2.16~-0.84% for CSD equation and within -0.20~1.10% for RKS equation. And the relative deviations of bubble point pressure for HFC143a/134a system are within -0.45~0.12% and -0.20~2.8% for CSD and RKS equations, respectively.

Investigation on the Selection of Capillary Tube for the Alternative Refrigerant R-407C

Chang Nyeun Kim,Young Moo Park 대한설비공학회 2000 International Journal Of Air-Conditioning and Refr Vol.8 No.1

The capillary tube performance for R-407C is experimentally investigated. The experimental setup is a real vapor-compression refrigerating system. Mass flow rate is measured for various diameter and length while inlet pressure and degree of subcooling are changed. These data are compared with the results of a numerical model. The mass flow rate of the numerical model is about 14% less than the measured mass flow rate. It is found that mass flow rate and length for R-407C are less than those for R-22 under the same condition. Based on this experimental study and the numerical model, a set of design charts for capillary tube of R-407C is proposed.

Poster Session : PS 0965 ; The Risk Factors of Gallbladder Polyps in Korean Patients with Chronic Hepatitis B

( Tae Nyeun Kim ),( Jae Hyun Park ),( Kook Hyun Kim ),( Kyeong Ok Kim ),( Si Hyung Lee ),( Byung Ik Jang ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Many studies reported a strong association between HBV infection and gallbladder(GB) polyps. This study aimed to identify the prevalence and risk factors associated with the development of GB polyps in patients with chronic hepatitis B(CHB). Methods: Patients (n = 4,168) with CHB diagnosed at Yeungnam University Hospital between January 2010 and December 2013 were analyzed retrospectively. Healthy people (n = 17,526) without CHB who visited at the health promotion center were enrolled as a control group. We compared the clinical, radiological, and laboratory fi ndings between CHB group and the control group. Results: The prevalence of GB polyps was signifi cantly higher in CHB group (11.2% vs. 9.2%, odds ratio [OR], 1.242; 95% confi dence interval [CI], 1.114-1.385; P<0.01). There was no difference in the prevalence of GB polyps according to age, BMI, and total cholesterol level in patients with CHB. The prevalence of GB polyps was higher in male patients with CHB (12.6% vs. 8.9%, p< 0.01). Liver cirrhosis and diabetes increased the risk for GB polyps by 2.718 times (95% CI, 2.187-3.377; P<0.01) and 1.529 times (95% CI, 1.218-1.918; P<0.01), respectively. The severity of the liver function according to the Child-Pugh class carried a signifi cantly greater risk of GB polyps formation [(OR, 4.606 for class C vs. class A, P<0.01) and (2.842 for class B vs. class A, P<0.01), respectively]. Multiple logistic regression analysis showed that diabetes, obesity, and Child-Pugh class were signifi cantly related to the risk of GB polyps formation in patients with CHB. Conclusions: The prevalence of GB polyps in patients with CHB is signifi cantly higher than general population, and the related risk factors in CHB group are diabetes, obesity, and severity of liver function.

Endoscopic Papillary Large Balloon Dilation Combined with Guidewire-Assisted Precut Papillotomy for the Treatment of Choledocholithiasis in Patients with Billroth II Gastrectomy

( Tae Nyeun Kim ),( Si Hyung Lee ) 대한소화기기능성질환·운동학회 2011 Gut and Liver Vol.5 No.2

Background/Aims: Endoscopic extraction of bile duct stones is difficult and often complicated in patients with a Billroth II gastrectomy. We evaluated a simpler technique to achieve an adequate ampullary opening for the removal of choledocholithiasis using endoscopic papillary large balloon dilation (EPLBD) combined with a guidewire-assisted needleknife papillotomy. Methods: Sixteen patients who had a Billroth II gastrectomy were included in this study. Following placement of the guidewire in the bile duct, a precut incision was made over the guidewire with a needle knife sphincterotome inserted alongside the guidewire. Balloon dilation of the ampullary orifice was gradually performed. Results: Needle knife papillotomy over the guidewire with subsequent EPLBD was successful in all patients. Complete stone removal was achieved in 15 (93.7%) patients in 1 session. However, 1 (6.3%) patient required mechanical lithotripsy with an additional procedure for complete ductal clearance, and there was 1 case of minor bleeding following the EPLBD. There were no cases of pancreatitis or perforation. Conclusions: EPLBD followed by guidewire-assisted needle-knife papillotomy appears to be a useful method with few technical diffi culties and a low risk of complications for the removal of bile duct stones in patients with prior Billroth II gastrectomy. (Gut Liver 2011;5:200-203)

시차분할 멀티 사이클을 적용한 냉장고의 성능에 관한 연구

김창년(Nyeun-Chang Kim),김윤영(Yoon-Young Kim),이재승(Jae-Seung Lee),배학균(Hak-Gyun Bae),김명욱(Myung-Wouk Kim),박용종(Yong-Jong Park) 대한설비공학회 2003 대한설비공학회 학술발표대회논문집 Vol.2003 No.-

초음파영상술을 이용한 절단된 경막외 카테터의 위치확인 및 수술적 제거

김성년(Sung Nyeun Kim),박철주(Cheol Joo Park),권오 대한통증학회 1997 The Korean Journal of Pain Vol.10 No.2

Continuous epidural blockade is a widely accepted, useful technique for providing anesthesia and analgesia. But there have been several anecdotal reports of complications such as: abnormal position, knotting, shearing of the catheter, etc. We experienced a case of shearing of the end of an epidural catheter which was difficult to remove from epidural space of a 39-year-old patient. Ultrasonogram proved to be very effective to confirm the presence and position of the retained catheter. We surgically removed the retained catheter as it could potentially lead to infection of the epidural space. We advocate ultrasorgram as an effective procedure to confirm and locate retained epidural ca- theter.

Effect of Hyperthermia on the Action of Pancuronium, Non-depolarizing Muscle Relaxant, in Rabbits

Kim, Sung Nyeun,Chung, Woon Hyok CATHOLIC MEDICAL CENTER 1977 Bulletin of the Clinical Research Institute Vol.5 No.1

It is evident that the response to relaxants may be altered by changes in temperature. There are conflicting reports regarding the effect of hypothermia on the response to neuromuscular blocking drugs. But recently, it have been found that decreasing ambient temperature causes statistically significant increase in the intensities of neuromuscular blockades by d-tubocurarine, pancuronium, succinylcholine, and decamethonium. Similiary, the intensities of the blocks decreased as the temperature was increased. This was confirmed in the intact cat by Miller et al, who attributed the greater intensity of block at low temperatures to the possible retardation of metabolism and renal excretion of the drugs. The effect of hyperthermia on the response to the neuromuscular blocker was not intensively studied. The effect of elevated body temperature on the neuromuscular blocking action of pancuronium, a recently introduced non-depolarizing muscle relaxant, was studied in rabbits.

The Effect of Nitroglycerin on the Neuromuscular blocking action of Atracurium and Pancuronium in Rabbits

Kim, Sung Nyeun,Song, Ho Kyong CATHOLIC MEDICAL CENTER 1988 Bulletin of the Clinical Research Institute Vol.16/17 No.1

This study was performed to determine the effects of nitroglycerin on neuromuscular blocking action of atracurium and pancuronium in rabbits. “Train of four” responses were recorded from the common peroneal nerve-anterior tibial muscle preparation stimulated by supramaximal train of four impulse. Previous administration of nitroglycerin prolonged the onset time and the recovery time of atracurium and pancuronium significantly. The results suggest that the prior use of nitroglycerin could prolong neuromuscular blocking action of atracurium and pancuronium.

비공식투자자의 창업기 투자의사결정요소 연구

김태년(Tae-Nyeun Kim),박선영(Sun-Youmg Park),송영화(Yeong-Wha Sawng) 한국콘텐츠학회 2018 한국콘텐츠학회논문지 Vol.18 No.9

창업은 국가 경제성장에 기여하고 고용창출 효과가 크므로 국가는 창업활성화의 다양한 정책들을 추진하고 있다. 그러나 기술창업은 2016년 현재 2013년 대비 오히려 5.0%p 감소하였다. 정부가 추진하는 창업투자활성화는 벤처캐피탈과 엔젤 펀드들을 통해 창업 이후 성장기 또는 주식상장 2~3년 전의 유망한 벤처기업들에 주로 투자되며, 실제적으로 창업기의 투자와는 투자의 시기적 차이가 있고, 이러한 벤처기업에 투자하는 투자의사결정요소에 관한 연구는 많다. 창업활성화는 민간의 창업투자가 활발하도록 환경조성이 필요하며 창업기에 투자하는 민간 투자금의 현금화 가능성과 수익성에 관해 투자자들의 기대에 대한 연구가 필요하다. 창업기에는 창업자, 가족, 친구, 바보들 등의 비공식투자자들에 의해 투자되고 공식투자자들인 벤처캐피탈 및 엔젤펀드 등의 전문투자에 비해 비정형화된 투자의사결정이 이루어지는 것이 일반적이다. 본 연구는 비공식투자자의 특성과 투자의사결정요소, 그리고 투자금의 현금화 가능성 및 투자수익성이 투자의도에 미치는 영향을 분석하는 것으로서, 현금화 가능성은 자영업창업의 투자의도에 매개효과가 있고, 투자수익성은 기업창업의 투자의도에 매개효과가 있는 것으로 분석되었다. The startup, which is a common noun to start a small business, has been recently one of main targets for policymakers due to its important role for job creation and considerable potential for sustainability of an economy. However, technological entrepreneurship decreased by 5.0% p from 2013 to 2016. The revitalization of entrepreneurial investment promoted by the government is mainly supported in fruitable venture companies at grow stage or 2~3 years before IPO through venture capital firms and angel funds. It is far from an investment at start-up. It is therefore necessary to motivate private investment to be active in the private start-up sector. In addition, the start-up investment requires institutional support and government support to meet the expectations of investors about the possibility of payback and profitability of private investment invested in the founding period. As a small entrepreneur at a comparably early stage in the lifecycle of business, investments for the startup are generally made by informal investors such as family, friends and fools, and their decision making processes are relatively non-programmed compared with ones for listed corporales such as venture capital and angel fund agency. This study focuses on analyzing decision making factors in investment, and verifying an impact of such factors, specifically the possibility of investment payback and investment profitability, in a decision-making process for the startup especially at the very early stage.