• 한국대기환경학회지
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• 제32권5호
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• pp.526-535
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• 2016

Recently, fine dust in atmosphere have been considerably issued as a harmful element for human. Nitrogen oxide ($NO_x$) exhausted from diesel engines and power plants has been disclosed as a main source of secondary production of fine dust. In order to prevent exhausting these nitrogenous compounds into atmosphere, a treatment system with selective catalytic reduction (SCR) catalyst with ammonia as a reductant has been used in various industries. Urea solution has been widely studied to supply ammonia into a SCR catalytic reactor, safely. However, the conversion of urea solution to ammonia has several challenges, especially on a slow conversion velocity. In the present study, a fast urea conversion system including a plasma burner was suggested and designed to evaluate the performances of urea conversion and initial operation time. A designed lab-scale facility has a plasma burner, urea nozzle, mixer, and SCR catalyst which is for hydrolysis of isocyane. Flow rate of methane that is a fuel of the plasma burner was varied to control temperatures in the urea conversion facility. From experimental results, it is found that urea can be converted into ammonia using high temperature condition of above $400^{\circ}C$. In the designed test facility, it is found that ammonia can be produced within 1 min from urea injection and the result shows prospect commercialization of proposed technology in the SCR facilities.

• Nutrition Research and Practice
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• 제8권2호
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• pp.220-226
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• 2014

BACKGROUND/OBJECTIVES: Arsenic, which causes human carcinogenicity, is ubiquitous in the environment. This study was designed to evaluate modulation of arsenic induced cancer by resveratrol, a phytoalexin found in vegetal dietary sources that has antioxidant and chemopreventive properties, in arsenic trioxide ($As_2O_3$)-induced Male Wistar rats. MATERIALS/METHODS: Adult rats received 3 mg/kg $As_2O_3$ (intravenous injection, iv.) on alternate days for 4 days. Resveratrol (8 mg/kg) was administered (iv.) 1 h before $As_2O_3$ treatment. The plasma and homogenization enzymes associated with oxidative stress of rat kidneys were measured, the kidneys were examined histologically and trace element contents were assessed. RESULTS: Rats treated with $As_2O_3$ had significantly higher oxidative stress and kidney arsenic accumulation; however, pretreatment with resveratrol reversed these changes. In addition, prior to treatment with resveratrol resulted in lower blood urea nitrogen, creatinine and insignificant renal tubular epithelial cell necrosis. Furthermore, the presence of resveratrol preserved the selenium content ($0.805{\pm}0.059{\mu}g/g$) of kidneys in rats treated with $As_2O_3$. However, resveratrol had no effect on zinc level in the kidney relative to $As_2O_3$-treated groups. CONCLUSIONS: Our data show that supplementation with resveratrol alleviated nephrotoxicity by improving antioxidant capacity and arsenic efflux. These findings suggest that resveratrol has the potential to protect against kidney damage in populations exposed to arsenic.

• 대한기계학회논문집B
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• 제36권7호
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• pp.767-774
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• 2012

신형경수로인 APR1400의 안전주입탱크에는 유량조절장치가 설치되어있다. 이러한 유량조절장치는 안전주입탱크 내부의 수위에 따라 유량조절장치 내부에 위치한 와류실의 유동양식이 변하도록 설계되어 있어, 피동적으로 유량이 조절되는 특성을 가지고 있다. 그러나 고유량에서 저유량으로 전환되는 과정에서 유동의 관성에 의해 상부 기체가 방출되는 현상이 존재하여, FD 성능에 영향을 줄 수 있다. 본 논문에서는 전산유체역학 코드인 CFX 코드를 활용하여 안전주입탱크의 유량전환현상시 기체의 방출현상에 대해 이상유체 자유수면모델 적용하여 계산하였다. 이를 통해 안전주입수의 수위 및 상부 충전기체의 거동을 평가하여 FD 성능특성에 미치는 영향을 분석하였다. 그 결과, 유량전환구간에서 자유수면의 높이가 순간적으로 낮아지게 되어, 상부의 기체가 일부 방출되는 것으로 평가되었으나, FD 성능특성에는 큰 영향을 미치지 않는 것으로 평가되었다.

• Natural Product Sciences
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• 제20권4호
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• pp.251-257
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• 2014

Chungsimyeonja-tang (CSYJT) is an herbal decoction that consists with 12 herbal medicines. CSYJT has been shown to have anti-stress, anti-allergic and anti-oxidant effects. The aim of this study was to determine flavonoid contents in CSYJT and evaluate its protective effect against cisplatin induced nephrotoxicity using both in vitro (porcine renal epithelial cell; PK15 cell) and in vivo (Sprague Dawley rat) experiments. In the present study, thee mean contents of baicalin, wogonoside and baicalein in CSYJT were 14.65, 5.27 and 0.02 mg/g, respectively. The CSYJT extract treatment attenuated the following alteration in porcine renal epithelial (PK15) cell: the increase in reactive oxygen species (ROS), the glutathione depletion and the increase in p53 expression induced by cisplatin treatment. In the in vivo study, rats were orally treated with CSYJT extract once a day for 28 days. Five days before the last treatment, cisplatin (5 mg/kg) was intraperitoneally injected to induce acute renal failure. Increased blood urea nitrogen (BUN) and creatinine (CRE) levels after cisplatin treatment were ameliorated by pretreatment of CSYJT extract. In addition, lipid peroxidation was decreased and antioxidant enzyme (glutathione) was recovered in CSYJT pretreated kidney tissue. In histopathological examination, CSYJT pretreated group showed ameliorated pathological alteration after cisplatin injection with decreased apoptosis. Taken together, pretreatment of CSYJT could ameliorate cisplatin-induced nephrotoxicity.

• 대한기계학회논문집B
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• 제34권7호
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• pp.689-696
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• 2010

디젤엔진은 높은 열효율과 우수한 연비 성능 등의 장점을 가지고 있으나, 기화된 연료와 주변 공기가 혼합된 후 착화되는 과정을 거치기 때문에 이론 공연비 영역에서는 질소산화물(NOx) 배출이 증가되는 문제점을 가지고 있다. 최근 활발히 연구되고 있는 높은 정화 효율을 가진 LNT 촉매는 희박 분위기 조건에서는 NOx를 흡장하게 되고 과농한 분위기에서는 환원 분위기 형성을 통하여 NOx를 저감시키게 된다. 희박 공연비에서 동작하는 디젤 엔진에서는 이러한 환원 과정을 이루기 위해 주기적으로 과농한 분위기를 형성해주어야만 하는데, 이러한 연구는 NOx 저감을 위해 HC를 포함한 환원제의 농도를 제어하는 기술로서 본 연구에서는 디젤을 연료로 하는 수소농후가스 발생장치를 이용하여 LNT 촉매에 환원제로서 수소농후가스를 직접 공급하는 방식으로 LNT 촉매의 NOx 저감 특성을 파악하였다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.133-137
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• 2007

An experimental study is conducted to evaluate and compare the use of BiodieseDI Fuel supplements at blend ratio of 10/90(BDF10) and 20/80(BDF20), in four stroke, direct injection diesel engine located at the authors' laboratory. especially this Biodiesel is produced from Rape oil at the authors' laboratory. The tests are conducted using each of the above fuel blends, in the engine working at a speed of 1800rpm and at a various loads. In each test, specific fuel consumption, exhaust emissions such as nitrogen oxides(NOx), carbon monoxide(CO) and Soot are measured. The results of investigation at various operating conditions are as follows (1) Specific fuel consumption is increased average 1.52%, maximum 1.84% at load 25% in case of BDF10, and average 1.98%, maximum 2.80% at load 25% in case of BDF20. (2) CO emission is decreased average 5.14%, maximum 6.09% at load 0% in case of BDF10, and average 7.75%, maximum 9.13% at load 0% in case of BDF 20. (3) NOx emission is increased average 2.97%, maximum 3.74% at load 0% in case of BDF10, and average 3.84%, maximum 4.67% at load 0% in case of BDF20. (4) Soot emission is decreased average 9.36%, maximum 10.85% at load 75% in case of BDF10, and average 11.99%, maximum 13.95% at load 75% in case of BDF20.

• 한국임상수의학회지
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• 제7권2호
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• pp.501-509
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• 1990

This study was designed to examine effects of $\alpha$$_2$-Adrenergic Antagonists on blood chemical values in xylazine-sedated dogs. Twenty-four crossbred dogs of both sexes were intramusculary injected with a standard dosage of xylazine(2.2mg/kg of body weight). Righting reflex was uniformly lost and considered to be the point of maximum sedation. When the dogs were maximally sedated, tested groups were in-travenously injected with yohimbine 0.125mg/kg, 4-aminopyridine(4-AP) 0.3mg/kg, and a combination of yohimbine with 4-AP. Control group was intravenously 1 $m\ell$ of physiological saline solution. Total protein(T.P), albumin, glucose, aspartate aminotransferase(AST), alanine aminotrnasferase(ALT), blood urea nitrogen(BUN) were analyzed in the conditions of 0-, 30-, 60- and 120-minute after the administration of drugs. The results obtained in the study were as follows. 1. Changes of T.P, albumin, AST, ALT and BUN values in the control group were not significant during or after xylazine administration for at least 120minutes. 2. No changes of T.P, albumin, AST, ALT and BUN values in the tested groups were observed during or after $\alpha$$_2$-Adrenergic Antagonists treatment. 3. Serum glucose values of control group were getting remarkably increased after xylazine injection. 4. The xylasine-induced hyperglycemia was reversed in the dogs administrated with $\alpha$$_2$-Adrenergic Antagonists. Therefore, the results of the study show that the combined treatment with antagonists may be useful for accidental overdoses of xylazine and rapid reversal of animals sedated with xylazine.

• Journal of Advanced Marine Engineering and Technology
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• 제39권1호
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• pp.8-12
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• 2015

비에스테르화 바이오 디젤유는 에스테르화 공정을 거치지 않기 때문에 공정에 드는 비용이 절감되며 경유에 5%로 혼합하여 전자제어 분사식 디젤엔진에 사용할 경우 에스테르화 바이오 디젤유보다 경유에 더 유사한 성능을 나타내었다. 이러한 연구를 바탕으로 경유에 5% 혼합된 비에스테르화 바이오 디젤유를 전자제어 분사식 디젤엔진에 적용하기 위해서는 성능 최적화가 필요하다. 본 연구에서는 비에스테르화 바이오 디젤유의 성능 최적화를 위한 기초 실험으로 연료소비율, 질소산화물 및 도시평균유효압력을 반응치로 정하고 제어 가능한 6가지 인자에 대해서 그 영향력을 평가하고자 부분요인배치법을 이용하여 25%와 50%의 부분 부하에서 실험을 수행하였다. 그 결과 6가지 인자 중 분사시기 및 커먼레일압력이 가장 큰 영향을 미쳤고 각 부하에서 영향의 크기는 다르게 나타났다.

• 한국식품영양과학회지
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• 제37권11호
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• pp.1389-1394
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• 2008

본 연구는 산겨릅나무의 식품학적 가치를 알아보고 기능성식품 소재로서의 이용.개발을 위하여 항산화 및 간 기능 보호효과를 탐색하였다. 항산화성 결과 가운데 총 폴리페놀은 EtOAc fr.에서 함량이 가장 많았고 BuOH fr., EtOH ex., $CHCl_3$ fr., hot water ex., aqueous fr. 순으로 높게 나타났다. 전자공여능은 EtOAc fr.과 BuOH fr.이 ascorbic acid와 유사한 전자공여능을 보였으며 SOD 유사활성능은 $250\;{\mu}g/mL$ 이하의 농도에서는 BuOH fr.이 가장 높게, 그 이상에서는 aqueous fr.에서 가장 높게 나타났다. LPS로 급성 간 손상을 유도한 마우스에서의 BuOH fr.의 간 기능 보호효과에서는 BuOH fr.을 전 처치한 다음 LPS를 투여한 군이 LPS만을 투여한 군보다 혈장 AST와 ALT의 활성은 유의하게 감소 되었으나 BUN의 농도는 유의성이 관찰되지 않았다. 간조직의 형태학적 관찰에서 BuOH fr.을 투여하고 LPS로 급성 간 손상을 유도한 군의 간세포는 염증과 괴사가 나타났지만 LPS군에 비하여 그 정도가 적은 것으로 나타났다.

• Journal of Acupuncture Research
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• 제32권3호
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• pp.15-25
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• 2015

Objectives : The purpose of this study is to investigate the effects of Pyrrosiae Herba herbal-acupuncture(PH-HA) at $KI_{10}$(Umgok) on nephritis induced by lipopolysaccharide(LPS) in rats. Methods : Rats were assigned to four groups: normal, LPS, saline and PH-HA. Rats in the saline and PH-HA groups were treated with saline injection and PH-HA respectively at $KI_{10}$, three times over the period of one week. All animals, except those in the normal group, were injected intra-peritoneally with LPS to induce nephritis. WBC, in blood, tumor necrosis factor alpha(TNF-${\alpha}$), cytokine-induced neutrophil chemoattractant 1(CINC-1), blood urea nitrogen(BUN), creatinine in serum, urinal volume, total protein creatinine in urine, and renal myeloperoxidase (MPO) were analyzed. Results : 1. PH-HA group showed significantly reduced levels of serum BUN, serum creatinine, TNF-${\alpha}$, and CINC-1 compared to the LPS group. Furthermore, a significant increase in urine output and more significant decreases in total protein in urine and MPO in renal tissue were observed in the PH-HA group when compared to the LPS group. 2. The PH-HA group showed significantly reduced levels of serum creatinine and renal MPO, and a more significant increase in urine output compared to the saline group. Conclusions : According to these results, it is postulated that PH-HA at $KI_{10}$ has anti-inflammatory and renal-protective effects on LPS-induced nephritis in rats, and both acupoint $KI_{10}$ and the herb Pyrrosiae Herba made contributions to these effects. Further studies on the interaction between acupoint $KI_{10}$ and the herb Pyrrosiae Herba may be needed.