http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
왕복동식 수소압축기의 스너버 내부 맥동압력에 관한 수치해석
심규진(KyuJin Shim),이중섭(ChungSeub Yi),악바르완다알리(Wanda Ali Akbar),정한식(HanShik Chung),정효민(HyoMin Jeong),김무근(MooGeun Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
Nowadays, study about hydrogen fuel which consist of hydrogen extraction and reform ing processes, fuel cell equipment, and receptacle are flourishing all over the world. Currently, Korea hydrogen station is still underdeveloping. And also the most important part which is hydrogen compressor has not been developed. Snubber is one of the important parts in hydrogen compressing system. It is installed before and after reciprocating hydrogen compressor. Snubber has two functions. One is making down pulsation waveform. Because pressure hydrogen gas where is after passing through reciprocation compressor part has high pulsation waveform, so this waveform has to decline. And the other function is precipitating alien substances to outside. Normally, even if 99.99% hydrogen gas is still containing alien substance. Buffer is set up inside snubber and the waveform will hit buffer. This snubber study uses CFD analysis, then it compares between with-buffer snubber and without-buffer snubber.
이경환(G. H. Lee),악바르(Wanda Ali Akbar),심규진(K. J. Shim),정한식(H. S. Chung),정효민(H. Min Jeong) 한국동력기계공학회 2007 한국동력기계공학회 학술대회 논문집 Vol.- No.-
The studies about hydrogen fuel which consist of hydrogen extraction and reforming process, fuel cell equipment, and receptacle are flourishing all over the world. But, Korean hydrogen station is still underdeveloping. And also a hydrogen compressor which is the most important part at the hydrogen station, has not been developed. Snubber is one of the most important parts in hydrogen compressing system. Snubber has function to reduce pulsation waveform and to remove the impurities in the hydrogen gas. A snubber has an inclined plate as a buffer, which is installed inside snubber. When the pressure loss and the pulsation of pressure within a snubber is minimized, the snubber could get more applicability. Therefore, a study to find an optimum geometric size on a several snubbers which have different buffer width, has been conducted using a numerical analysis. The numerical results show the special characters of snubber according to various buffer angle. The minimum pressure loss ratio occurs when the buffer angle is 35. and the minimum pressure pulsation ratio occurs when the buffer angle 10.
이경환(KyeongHwan Lee),심규진(KyuJin Shim),악바르 완다 알리(Wanda Ali Akbar),정한식(HanShik Chung),정효민(HyoMin Jeong) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11
Nowadays, study about hydrogen fuel which consist of hydrogen extraction and reforming processes, fuel cell equipment, and receptacle are flourishing allover the world. Currently, Korea hydrogen station is still underdeveloping. And also the most important part which is hydrogen compressor has not been developed. Snubber is one of the important parts in hydrogen compressing system. It is installed before and after reciprocating hydrogen compressor. Snubber has two functions. One is making down pulsation waveform. Because pressure hydrogen gas where is after passing through reciprocation compressor part has high pulsation waveform, so this waveform has to decline. And the other function is precipitating alien substances to outside. Normally, even if 99.99% hydrogen gas is still containing alien substance. Buffer is set up inside snubber and the waveform will hit buffer. This snubber study uses CFD.
수소압축기 스너버 관로 내부의 맥동파 특성에 관한 연구
김규진(K. J. Shim),이중섭(C. S. Yi),악바르 완다 알리(Wanda Ali Akbar),정한식(H. S. Chung),정효민(H. M. Jeong) 한국동력기계공학회 2006 한국동력기계공학회 학술대회 논문집 Vol.- No.-
An experiment to observe reduction of pressure fluctuation in the compressing system utilizing snubber has done. The experiment measured pressure at inlet and outlet of snubber. It used an air compressor as a model of hydrogen one. Snubber with buffer and snubber without buffer were used to get comprehensive comparison between both of that snubber. An analysis by using Fast Fourier Transform (FFT) method was conducted to verify working pressure frequency. With this method pure signal of static pressure was filtered from noisy signal. The experiment was run for several speeds of piston movement. It was controlled by adjustable frequency regulator that controled rotation of actuator motor. This was connected to the piston-reciprocating compressor with V -belt. From result obtained, the fluctuation was increasing proportionally when frequency of driver motor was increased.
심규진(K. J. Shim),이중섭(C. S. Yi),악바르 완다(Wanda Ali Akbar),정한식(H. S. Chung),정효민(H. M. Jeong),김무근(M. G. Kim) 한국동력기계공학회 2006 한국동력기계공학회 학술대회 논문집 Vol.- No.-
Nowadays, study about hydrogen fuel which consist of hydrogen extraction and reforming processes, fuel cell equipment, and receptacle are flourishing all over the world. Currently, Korea hydrogen station is still underdeveloping. And also the most important part which is hydrogen compressor has not been developed. Snubber is one of the important parts in hydrogen compressing system. It is installed before and after reciprocating hydrogen compressor. Snubber has two functions. One is making down pulsation waveform. Because pressure hydrogen gas where is after passing through reciprocation compressor part has high pulsation waveform, so this waveform has to decline. And the other function is precipitating alien substances to outside. Normally, even if 99.99% hydrogen gas is still containing alien substance. Buffer is set up inside snubber and the waveform will hit buffer. This snubber study uses CFD analysis, then it compares between with-buffer snubber and without-buffer snubber.
4-Hydroxynonenal Induces Endothelial Cell Apoptosis via ROS and Peroxynitrite Generation
Sang Woon Chung(정상운),Su Bog Yee(이수복),Ji Young Lee(이지영),Mohammad Akbar Hossain(호세인 모하메드 악바르),Dong Hwan Kim(김동환),Jeong-Hyun Yoon(윤정현),Hae Young Chung(장정윤),Nam Deuk Kim(김남득) 한국생명과학회 2011 생명과학회지 Vol.21 No.7
지질과산화로부터 생성된 aldehyde 중 4-hydroxynonenal (HNE)는 산화적 손상과 관련된 다량의 arachidonic acids, linoleic acids 등으로부터 생성될 수 있다. 그러므로 HNE는 산화적 스트레스와 관련된 세포사에서 중요한 매개인자로 작용을 할 수가 있을 것이다. 본 연구는 HNE가 세포사를 유발할 것이라 가정하고, 먼저 흰쥐 전립선 유래 내피세포인 YPEN-1 세포에서 세포독성을 측정하였다. 세포생장 저해능력은 HNE를 5~15 μM 농도로 처리하여 형태적 변화와 MTT assay를 통하여 결과를 관찰하였다. 그 결과 HNE가 이 세포에서 핵형의 변화와 세포사를 유발시키는 것을 각각의 실험을 통해 확인이 되었다. 또한 이 사실을 단백질의 변화를 통하여 확인을 할 수가 있었다. HNE를 24시간 처리한 세포에서 poly(ADP-ribose) polymerase 단백질 분절이 매개되었고 Bax의 발현량이 증가하였다. 또한 세포내의 활성 산소종들을 발생시켰다. 이에 생성된 활성 산소종과 peroxynitrite가 세포사와 관련이 있는가를 밝히기 위하여 이들의 포식자들인 N-acetylcysteine과 penicillamine을 본 연구에서 사용하였다. 이들 포식자들에 의해 HNE에 의해 유도되는 세포사가 억제가 되었기에 산화적 활성화가 HNE에 의해 유도된 세포사와 관련이 있음을 알 수 있었다. 이러한 결과들은 HNE가 내피세포에서 ROS와 peroxynitrite 생성을 통하여 세포사를 일으킨다는 사실을 뒷받침해 준다. The formation of reactive lipid aldehydes, 4-hydroxynonenal (HNE) is shown to be derived from fatty acid hydroperoxides through the oxidative process. Among its known effects in cytotoxicity, HNE has been implicated in apoptotic cell death. To delineate its putative role as a potential mediator, we investigated the mechanism by which HNE induces apoptosis of endothelial cells (ECs). The anti-proliferative effects of HNE were tested through MTT assay after exposure to various concentrations (5~15 μM) of HNE. We observed apoptotic bodies with propidium iodide staining, and measured the HNE induction of endothelial apoptosis by flow cytometry assay. We observed that cells exposed to HNE for 24 hr resulted in increased poly(ADP-ribose) polymerase cleavage and up-regulation of Bax. Data on the HNE action strongly indicated the involvement of reactive species, namely, intracellular ROS, nitrite, and peroxynitrite. To obtain evidence on the implication of ROS and peroxynitrite in HNE-induced apoptosis, a ROS scavenger, N-acetylcysteine (NAC), and a peroxynitrite scavenger, penicillamine, were tested. Results clearly indicate that the induction of apoptosis by HNE was effectively inhibited by NAC and penicillamine. Based on the present data, we conclude that the endothelial apoptosis induced by HNE involves both ROS generation and peroxynitrite activity. Our new data could lead to a redefinition of HNE action on apoptosis in ECs.