• 소성∙가공
• /
• 제32권2호
• /
• pp.61-66
• /
• 2023

The quality of the sheared surface affects the stretch flangeability of steel sheet. The quality of sheared surface is influenced by several process factors such as die clearance, shape of cutting edge, use of counter punch, and shear. In this paper, the influence of these shearing process factors on the stretch flangeability of the HSS (DP980) was analyzed through a shearing and a stretch flangeability test. When the die clearance was 10%, the effect of these shearing process factors on the stretch flangeability was the greatest, and the use of an acute angle blade was found to be more advantageous in the stretch flangeability than a right angle blade. It was found that the stretch flangeability was improved when active bending was applied during shearing.

• 대한한방내과학회지
• /
• 제38권1호
• /
• pp.20-31
• /
• 2017

Objectives: This study investigated the effect of SM-2015 on blood alcohol clearance and hangover. We undertook this study to test whether SM-2015 is effective in decreasing blood alcohol concentration and preventing the symptoms of alcohol-induced hangover. Methods: Twenty healthy volunteers participated in this randomized crossover study. All participants were classified between an SM-2015 intake group (test group) and a non-intake group (control group). The primary outcome measure was the difference in blood alcohol concentration and hangover severity scores between the test and control groups. The secondary outcome measure was the difference in a liver function test (LFT) between the test and control groups. Results: After alcohol exposure, the sensitivity scores of blood alcohol concentration and hangover symptoms (sleepiness, dizziness, nausea, weakness, stomach pain, diarrhea, and concentration disorder) were significantly decreased in the SM-2015 intake group compared with the non-intake group. There were no differences in the LFT results between the SM-2015 intake group and the non-intake group. Conclusions: SM-2015 is effective in decreasing blood alcohol concentration and preventing the symptoms of alcohol-induced hangover. Larger studies are required to confirm these findings.

• Journal of the Korean Wood Science and Technology
• /
• 제44권5호
• /
• pp.736-742
• /
• 2016

나무못은 다양한 구조물의 목재부재들을 연결하는데 일반적으로 사용된다. 하지만 국산재의 나무못 유지력에 대한 자료는 매우 부족하다. 본 연구는 나무못의 직경과 천공여척이 유지력 특성에 미치는 영향에 대해 알아보기 위해 실시했다. 실험 블록은 두께 15 mm인 소나무와 잣나무 목재로 제작했다. 6, 8 및 10 mm 직경인 나무못은 밤나무, 잣나무 및 백합나무 목재로 각각 제작했다. 연구결과 나무못 직경이 증가하면 유지력은 선형으로 증가했지만 유지력 강도는 감소했다. 본 연구는 또한 천공여척이 작아질수록 유지력과 유지력 강도도 선형으로 증가하는 것을 보였다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권1호
• /
• pp.9-15
• /
• 2005

A bioartificial liver (BAL) is a medical device entrapping living hepatocytes or immortalized cells derived from hepatocytes. Many efforts have already been made to maintain the functions of the hepatocytes in a BAL device over a long term. However, there is still some uncertainty as to their efficacy. and their limitations are unclear. Therefore, it is important to quantitatively evaluate the metabolic functions of a BAL. In previous studies on in vitro BAL devices, two test methods, an initial bolus loading and constant-rate infusion plus initial bolus loading, were theoretically carried out to obtain physiologic data on drugs. However, in the current study, the same two methods were used as a perfusion model and derived the same clearance characterized by an interrelationship between the perfusate flow rate and intrinsic clearance. The interrelationship indicated that the CL increased with an increasing perfusate flow rate and approached its maximum value, i.e. intrinsic clearance. In addition, to set up an in vivo BAL system, the toxic plateau levels in the BAL system were calculated for both series and parallel circuit models. The series model had a lower plateau level than the parellel model. The difference in the toxic plateau levels between the parallel and series models increased with an increasing number of BAL cartridges.

• 한국자동차공학회논문집
• /
• 제23권2호
• /
• pp.191-198
• /
• 2015

In this study, the flow characteristics at the ventilation holes was analyzed by using numerical method when carbon composite brake disk was rotated at a constant speed. In order to ensure the validity of the analysis results, grid dependency test was performed by considering the accuracy and appropriateness, and 4mm mesh size was selected for decrease of the maximum error rate 63.6%. As a result, the outside air flows in the clearance between the disk and shaft in case of B model. whereas, the outside air flows in the clearance or the outlet of the ventilation holes in case of A and C models. And also average static pressure at the outlet was changed depending on shape of the ventilation holes and rotational speed of the disk in case of A and C models. Besides, in the B model, intake air according to the clearance goes with side surface of ventilation hole, and so increased by mean velocity of 4.64m/s and mean pressure of 0.58pa in the ventilation hole outlet, in case of disk rotational speed of 146.21rad/s.

• 설비공학논문집
• /
• 제17권4호
• /
• pp.325-332
• /
• 2005

This paper addresses the development of a scroll expander for power generation from relatively low temperature steam source. It has a double-sided orbiting scroll member so that no thrust bearing is needed to support the base plate of the orbiting scroll. Three power transmission shafts are placed at the periphery of the orbiting scroll base plate, and these shafts can also function as anti-rotation devices. Final output is obtained from the main central shaft engaged with the three power transmission shafts through gear assembly. The clearance between the fixed and orbiting scroll elements was estimated by comparing measurement of the mass flow rate with calculation results of a computer simulation. Due to large clearance, the expander total and volumetric efficiencies were measured to be $34\%\;and\;43\%$, respectively. It has been shown through the computer simulation that the total and volumetric efficiencies could be improved to $65\%\;and\;83\%$, respectively, if the current clearance is reduced by half.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권10호
• /
• pp.5753-5759
• /
• 2013

Curcumin and curcumin containing polyherbal preparations have demonstrated anti-microbial and antiviral properties in pre-clinical studies. Till date no therapeutic intervention has been proved to be effective and safe in clearing established cervical human papillomavirus (HPV) infection. The present study evaluated the efficacy of Basant polyherbal vaginal cream (containing extracts of curcumin, reetha, amla and aloe vera) and of curcumin vaginal capsules to eliminate HPV infection from cervix. Women were screened by Pap smear and HPV DNA test by PCR. HPV positive women without high grade cervical neoplasias (N=287) were randomized to four intervention arms to be treated with vaginal Basant cream, vaginal placebo cream, curcumin vaginal capsules and placebo vaginal capsules respectively. All subjects were instructed to use one application of the assigned formulation daily for 30 consecutive days except during menstruation and recalled within seven days of the last application for repeat HPV test, cytology and colposcopy. HPV clearance rate in Basant arm (87.7%) was significantly higher than the combined placebo arms (73.3%). Curcumin caused higher rate of clearance (81.3%) than placebo though the difference was not statistically significant. Vaginal irritation and itching, mostly mild to moderate, was significantly higher after Basant application. No serious adverse events were noted.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.773-774
• /
• 2008

As an Embedded system get more complicated, the importance of the software test increases. Especially it is mandatory to test the embeded software for a charge degrade of the development company which is happened due to the error, a danger element clearance to the customer, a performance enhance of the system. In this paper, we propose efficient test method which discovers the bug an embedded system using suitable test case selection and automation test.

• 한국산학기술학회논문지
• /
• 제20권10호
• /
• pp.117-124
• /
• 2019

국군이 운용중인 대부분의 군 전용차량은 개발이 완료된지 15년이 넘었으며, 개발 당시의 기술력과 정비성을 고려하여 수동변속기를 채택하고 있다. 수동변속기는 엔진과 변속기 사이에 동력을 조절/차단하는 클러치를 포함한다. 본 연구의 대상이 되는 2.5톤 군용차량은 수동변속기와 클러치 시스템을 적용하고, 클러치 커버와 릴리스 베어링 간극을 수동으로 조절해야 했다. 이러한 특성으로 인하여 클러치 디스크 조기마모, 클러치 커버 파손 등의 품질문제가 발생하였다. 본 연구는 발생된 품질문제를 해결하기 위하여, 클러치 커버와 릴리스 베어링의 간극을 자동으로 설정하도록 하고 클러치 디스크 자체의 성능도 향상시키는 과정을 거쳤다. 개선된 시스템을 평가하기 위해서, 단시간에 기어변속을 하는 가속내구시험을 수행하였으며 추가적으로 군인이 직접 운전을 하여 차량에 적용하였을 때 이상이 없음을 증명하였다. 본 연구활동을 통해, 클러치 간극을 조정할 필요가 없도록 하여 차량 정비 인력의 정비시간을 단축하였다. 또한, 클러치 간극을 조정해 주지 못함으로써 발생되는 품질문제를 해소하여, 근본적인 개선책을 제시하였다고 볼 수 있다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2009년도 추계학술대회 논문집
• /
• pp.792-796
• /
• 2009

Application of air foil bearing (AFB) is widely using to cope with requirements of high speed and high efficiency system at turbo machinery. At same time, a wide variety of AFB design methods are required. In this paper, the AFB design factor influencing the most greatly in bearing performance was selected through theoretical analysis and vibration test was conducted using selected factor. Through this process, AFB system applicable for vehicle turbo machinery was developed.