• 한국정밀공학회지
• /
• 제21권8호
• /
• pp.120-128
• /
• 2004

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, the electronic equipment of a satellite consists of an aluminum case containing PCB. Each PCB has resistors and IC. Noise and vibration of the wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation, random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when the frequency of random vibration meets with natural frequency of PCB, fatigue fracture may occur in the part of solder joint. The launching environment, thus, needs to be carefully considered when designing the electronic equipment of a satellite. In general, the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM or vibration test. In this study, the natural frequency and dynamic deflection of PCB are measured by FEM, and the safety of the electronic components of PCB is evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs ranging from the electronic equipments of a satellite to home electronics.

• Journal of Ginseng Research
• /
• 제21권3호
• /
• pp.174-186
• /
• 1997

In this study, rat hepatocytes known to have active carbohydrate metabolism were obtained by using the liver perfusion technique to examine the hypoglycemic action of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only, The specific activities of some regulatory enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and glucose 6-phosphatase, in main pathways which were directly related to the glucose metabolism were compared between these two kinds of hepatocytes cultured in two different media. The effects of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] under the concentration of $10^3$~$10^6$% on these enzymes In hepatocytes were also investigated, when they were added to these two media. The results were as follows. The specific activity of enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one, however, their decreased activity was recovered after the addition of ginseng components at all range of concentrations. The increased specific activity of these on - zymes was shown by the addition of ginseng components to the control group. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their Increased activity was decreased after the addition of ginseng components at all range of concentrations. The same results were obtained after the addition of ginseng components to the control group. These results suggest that the red ginseng saponin components might better diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or Indirectly though more detailed studies were needed.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.352-355
• /
• 2000

Production of pullulan by Aureobasidium pullulans HP-2001 with agro-industrial byproducts was investigated. Agro-industrial byproducts from the rice processing industry for the traditional Korean food (AIB-A), apple juice production (AIB-B), and soybean sauce production (AIB-C) were used for carbon and nitrogen source for production of pullulan. Major components of AIB-A were glucose, maltose, maltotriose, and dextran. AIB-A and B were found to be good substitute to glucose as carbon source. Productivity of pullulan with AIB-A and B as carbon source was similar to that glucose. Molecular weight of pullulan produced with AIB-A and B was higher than that with glucose. Major components of AIB-B and C were carbohydrate, protein, fat and ash. AIB-C was also a good substitute to yeast extract as nitrogen source. Some of physiological conditions were examined for the large scale production of pullulan.

• 생약학회지
• /
• 제29권2호
• /
• pp.120-124
• /
• 1998

For the purpose of evaluating protective components against alcohol-induced toxicity, the active components enhancing alcohol metabolism was pursued from water soluble fraction by ethanol precipitation and DEAE-cellulose chromatographic technique. As a result, various high molecular weight fractions from Aloe vera and Aloe arborescens, on a single oral administration in rats were found to cause a significant decrease in the blood ethanol concentration as well as enhancement of liver cytosolic ADH and ALDH activities and among which, a strong acidic high molecular weight fraction was demonstrated to exhibit the most potent enhancing activity on ethanol metabolism.

• Journal of Ginseng Research
• /
• 제14권2호
• /
• pp.217-220
• /
• 1990

Two lignanes, Comp.-I, mp 108-1$0^{\circ}C$ and Comp.-II 50-52$^{\circ}$were isolated from Korea ginseng extract by repeated column chromatographic purification. Comp.-I was identified as gomisin-N and Comp.-II as gomisin-A by spectrometric analysis, both of which have already been described as the anti-hepatotoxic lignan components of Schizandra chinesis Bail.

• 한국식품위생안전성학회:학술대회논문집
• /
• 한국식품위생안전성학회 1994년도 하계 학술 심포지움
• /
• pp.17-22
• /
• 1994

Food additives are minor components which are used to enhance nutritive or sensory values, and to improve shelf life of foods. In foods, natural additives are preferred over artificial or synthetic materials because of concern on food safety. Many biotechnological techniques have been applied to the production of food additives since the biotechnology has been utilized to prodyce many flavor components such as glutamate, 5'-nucleotides, esters, 2,3-bytadione, pyrazines, terpenes, and lactones. Natural flavors, fragrances, sweetners, and colorants can be produced by plant cell culture. Many lactic acid bacteria produce bacteriocins such as nisin or diplococcin. These bacteriocins are used as safe preservatives in foods and many researches on the improvenment of bacteriocin productivity by genetic engineering are in progress.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2001년도 Proceedings of the Pharmaceutical Society of Korea
• /
• pp.197.3-198
• /
• 2001

• Natural Product Sciences
• /
• 제7권2호
• /
• pp.27-32
• /
• 2001

In addition to known cucurbitacins, a glucosphingosine type cerebroside and amino acids were isolated from the roots of Trichosanthes kirilowii. The structure of cerebroside was determined as soya-cerebroside I by means of spectroscopic methods. Fifteen amino acids were identified as aspartic acid, glutamic acid, serine, glycine, histidine, citrulline, threonine, alanine, proline, tyrosine, valine, isoleucine, leucine, phenylalanine and tryptophan, among which the major components such as citrulline, phenylalanine, leucine/isoleucine and valine were isolated.

• 생약학회지
• /
• 제22권4호
• /
• pp.215-218
• /
• 1991

Paeony root was extracted and fractionated for the identification of the platelet anti-aggregatory components. And gallic acid methylester was isolated as the major component from the active sub-fraction F302.

• Archives of Pharmacal Research
• /
• 제9권1호
• /
• pp.21-23
• /
• 1986

Over twelve alkaloids were delected in the roots of Panax ginseng C. A. Meyor. Among them three alkaloids were isolated and were identified as $N_{9}$-formylharman, ethyl $\beta$-carboline-1-carboxylate and perlolyrine on the basis of spectroscopic studies.