• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1317-1319
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• 1995

In this paper, we studied reduction characteristics of NOx gas produced from diesel engine combustion using by point-plane electrode. Here, input voltage forms were types of three [DC, AC, DC Positive pulse] and NOx gas of 1700ppm was composed of NO 1665ppm, $NO_2$ 35ppm on balance of $N_2$. We investigated NOx reduction characteristics as various of parameters, are gas flow rate, input voltage form and, humidity. From the results of study, reduction characteristics of NOx exhibited good when gas flow rate was small, input voltage was DC and much humidity were contained to NOx gas.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.2180-2185
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• 2003

Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ mixtures are performed at atmospheric pressure in order to understand the effect of HCl on the NOx reduction. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios the flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As HCl is added into $H_2/Air$ flame as additive, its chemical effect causes the reduction of radicals (H, OH, and O), and then the decrease of the net rate of NO production. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect.

• 대한물리치료과학회지
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• 제21권1호
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• pp.53-58
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• 2014

Background : The purpose of this study is to identify the level of positive influence on the pain and the gripping power in patients with tennis elbow by comparing the TENS treatment method and the kinesio taping therapy with good accessibility among the kinesio taping therapy and electrical therapy. Methods : Targeting the patients diagnosed with tennis elbow, the subjects were categorized in groups of four, each of electrical therapy group and kinesio tape therapy group where the degree of pain reduction through VAS before and after the treatment of each group and the measurement of the degree of gripping power increase using the gripping power measurement tool as well as the pain reduction changes and gripping power increase before and after the treatment between the two groups were compared. Result : As a result, the electrical therapy group and the kinesio tape group were able to obtain the results of pain reduction and gripping power increase through VAS before and after the treatment, but for all pain reduction and gripping power increase, it had no statistically significant changes(p>.05). In addition, in the changes of pain reduction and changes of gripping power increase before and after the treatment, there were no statistically significant differences between the electrical therapy group and the kinesio tape group(p>.05). Conclusion : Based on the results so far, it is thought that the kinesio taping therapy can positively influence the pain reduction of patients with tennis elbow and increase of gripping power.

• 한국유기농업학회지
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• 제20권4호
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• pp.503-518
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• 2012

본 연구에 적용된 한국형 무경운(no-tillage)농법은 한국의 기상특성 및 농업현실에 맞도록 초기 두둑을 형성한 후 이를 지속적으로 재활용하는 방식을 적용하였다. 한국형 무경운 농법은 생산량 저하 등 부정적인 영향이 거의 없는 것으로 보고되었으며 경운작업 등 농자재사용은 크게 절감되는 효과로 인하여 에너지 및 농자재 비용의 절감과 노동시간 단축 등 긍정적인 효과가 높은 것으로 보고되었다(Yang et al., 2012). 무경운농법에 의한 고추재배는 일반적인 고추재배 방식과(국가평균) 비교하여 10a ($1,000m^2$)당 $344.7kgCO_2$(58%)의 온실가스저감 효과를 갖는 것으로 분석되었다. 이 중 비료절감에 의한 직-간접효과가 92%, 에너지사용 절감에 의한 효과는 44%로 높은 탄소저감효과를 나타내었다. 또한, 무경운농법의 직접적인 효과에 부가하여 무경운방식의 토양관리는 일반적으로 시간이 흐를수록 토양의 탄소격리 효과가(carbon sequestration effect) 높아지는 특징을 갖고 있기 때문에 연속적인 무경운농법을 수행할 경우 연구대상지의 지속적인 탄소저감 효과가 기대된다. 본 연구의 결과를 바탕으로 한국형 무경운농법은 농업부문 국가온실가스 저감목표 달성을 위한 주요한 녹색농업기술(agro-green technologies)로서 역할을 수행할 것으로 기대되며, 관련기술의 보급 및 확대를 위한 국가적 차원의 노력이 절실히 요구된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.967-972
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• 2001

The emission of $NO_{x}$ during coal combustion is a major reason of environment impact. $NO_{x}$ is an acid rain precursor and participates in the generation of smog through ozone production. $NO_{x}$ can be divided into thermal $NO_{x}$, fuel $NO_{x}$ and prompt $NO_{x}$. Thermal $NO_{x}$ is formed in a highly temperature condition dependent. Fuel $NO_{x}$ is dependent on the local combustion characteristics and initial concentration of nitrogen bound compound, while prompt $NO_{x}$ is formed in a significant quantity in some combustion environments, such as low temperature and short residence times. This paper presents numerical simulation of the flow and combustion characteristics in the furnace of a tangential firing boiler of 500MW with burners installed at the every comer of the furnace. The purpose of this paper is to investigate the reduction of $NO_{x}$ emission in a 500MW pulverized coal tangential firing boiler with different OFA's and burner angles. Calculations with different air flow rates of over fired air(OFA) and burner angles are performed.

• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.721-726
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• 1995

In this paper, reduction characteristics of NOx gas produced from diesel engine combustion is studied by using pulse corona discharge. Nox concentration of 1900ppm (NO 1870, NO$\sub$2/ 30 ppm, N$\sub$2/ balance gas) was controlled in a fixed quantity of 280ppm, using a flow meter. Reactors are composed of cylinder type. NOx reduction rate is investigated with discharge electrode diameter[0.5,1,3,4.phi.], reactor length [130,300mm], reactor materials[Copper, Poly Vinyl Chloride] and Input voltage[DC, AC, DC Pulse square voltage]. In the result, NOx reduction rate is the best of all in copper reactor, small electrode diameter[0.5.phi.], DC pulse voltage and long reactor[300mm]. Then Teduction rate of NOx is about 93%.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.32-44
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• 2002

Selective catalytic reduction of nitric oxide by methane in the presence of excess oxygen was investigated over copper and cobalt ion-exchanged ZSM-5 zeolites. Copper ion-exchanged ZSM-5(Cu-ZSM-5) has the limitations for commercial applications to lean-bum gasoline and diesel engines due to low thermal stability and resistance to water vapor and sulfur dioxide. But cobalt ion-exchanged ESM-5(Co-ZSM-5) is more active at high temperatures and also stable to water vapor and sulfur dioxide for catalytic reduction of nitric oxide by methane. The catalytic activity of Cu-ZSM-5 for NO reduction increases with increasing temperatures, reaches the maximum conversion of 23.0% at 350\"C. and then decreases with higher temperatures. In the meantime catalytic activities of Co-ZSM-5 show the maximum conversion of 25.8% at $500^{\circ}C$ Therefore Co-ZSM-5 catalysts have higher thermal stability at high temperatures. Catalytic activities of both zeolites were remarkably enhanced with the existence of oxygen in the exhaust. It is noted that the catalytic activity of Cu-ZSM-5 decreases with the increasing concentration of methane while the catalytic activity of Co-ZSM-5 decreases with increasing contents of methane in the exhaust. This may imply the existence of different paths of NO reduction by methane in the presence of excess oxygen fur Cu-ZSM-5 and Co-ZSM-5 catalysts. For binary metal ionexchanged ZSM-5, the primary ion-exchanged metal may be masked by secondary ion-exchanged component, which plays the important role for catalytic activities of binary metal ion-exchanged ZSM-5, Therefore CuCo-ZSM-5 catalysts show the similar volcano-shaped curves to Cu-ZSM-5 catalysts between the activity and temperature. It Is interesting that the activities of CoCu-ZSM-5 catalysts indicate almost no dependence on the concentration of methane in the exhaust.aust.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권6호
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• pp.297-300
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• 2014

Objectives: To compare the clinical and radiological outcomes after closed reduction (CR) and open reduction and internal fixation (ORIF) in the management of subcondylar fractures. Materials and Methods: Forty-eight patients presenting with subcondylar fracture between January 2010 and March 2013 were evaluated retrospectively. Fifteen patients were treated with CR and 33 patients with ORIF. The clinical and radiologic parameters were evaluated during follow-up (mean, 7.06 months; range, 3 to 36 months). Results: In the CR group, no patients had any problems with regard to the clinical parameters. The average period of maxillomandibular fixation (MMF) was 5.47 days. The preoperative average tangential angulation of the fractured fragment was $3.67^{\circ}$, and loss of ramus height was 2.44 mm. In the ORIF group, no clinical problems were observed, and the average period of MMF was 6.33 days. The preoperative average tangential angulation of the subcondylar fragment was $8.66^{\circ}$, and loss of ramus height was 3.61 mm. Conclusion: CR provided satisfactory clinical results, though ORIF provided more accurate reduction of the fractured fragment. So there is no distinct displacement of fractured fragment, CR should be selected than ORIF because of no need for surgery.

• Archives of Plastic Surgery
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• 제33권6호
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• pp.792-796
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• 2006

Purpose: After exposure of fracture site, the proximal segment must be reduced to their preinjury position for open reduction of fractured mandibular condyle. We examined the use of inter-maxillary fixation screws or titanium screws tied with stainless steel wire to assist in positioning of proximal segment. Since it enables to make a relatively small preauricular incision by not disturbing the operative field like Moule pin, we can reduce the danger of injury to the facial nerve. Methods: A preauricular approach was used for exposure, reduction, and rigid fixation in 4 cases of mandibular condylar fractures. Inter-maxillary fixation screws or titanium screws tied with stainless steel wire were used to assist in aligning proximal segment. The joints were submitted to functional exercises and postoperative radiologic and clinical follow-ups were performed. Results: No facial nerve lesions were found in all 4 cases. Radiologic follow-up showed correct reduction and fixation in all 4 cases. Clinical follow-up showed an initial limitation, but normal morbility of the condyle was achieved within 4 months after the operation, with a maximum mouth opening of $34.1{\pm}5.2mm$ after 12 months. There found no occlusal disturbances, no trismus, no lateral deviations of the mandible. Conclusion: By using Inter-maxillary fixation screws tied with stainless steel wire, it was shown that reducing the proximal segment to their preinjury position is easy to perform and it enables us to make a minimal dissection below preauricular skin incision to avoid facial nerve injury.

• 청정기술
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• 제25권1호
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• pp.63-73
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• 2019

연소공정 내에서 질소산화물 배출을 저감하는 선택적 무촉매 환원장치 내부의 화학반응 및 저감효율에 대한 수치해석이 실행되었다. 선택적 무촉매 환원장치에서 저감된 질소산화물은 질소뿐만 아니라 아산화질소로도 전환된다. 아산화질소는 온실가스로써 지구온난화에 영향을 끼치기 때문에 선택적 무촉매 환원장치 내의 질소산화물 제어와 동시에 아산화질소 생성제어가 요구되어진다. 본 연구에서는 선행연구에서 실행된 실험과 온도조건과 가성소다의 첨가량이 동일한 선택적 무촉매 환원장치 내의 전산해석을 실시하고 비교하여 전산해석의 신뢰성을 확인하고, 가성소다 첨가량을 추가적으로 조절하여 질소산화물의 저감 효율과 아산화질소 생성량을 예측하였다. 전산해석은 후단의 측정점을 설정하여 각 물질의 질량분율을 확인하였다. 세부적으로는 측정점에서 유동방향에 수직한 면을 설정하여 온도 조건과 가성소다 첨가량에 따른 각 물질의 평균 질량분율을 비교하였다. 실험값과 전산해석에 의한 모사값은 최대 18.9%의 오차를 보이며 대체적으로 잘 예측됨을 확인하였으며 가성소다 첨가량을 증가시켰을 땐 70% 이상의 제거율의 온도 범위가 넓어지는 것을 확인하였다. 따라서 반응온도의 낙차가 크고 잦은 폐기물 소각시설 등에서 효과적일 것으로 예상된다.