고망간강의 기계적 성질에 미치는 Mo의 영향

황승준 대진대학교 첨단소재연구소 1998 첨단소재연구소논문집 Vol.1 No.-

Austenitic Mangames Steel is extremely tough non-magnetic alloy which is characterized by high strength, high ductility and excellent resistance to wear. In the form of castings or rolled shapes, it serves many industrial requirements economically and is particularly useful for servere service that combines abrasion and heavy impact such as hammer, Jaw plate. In this study, the effect of Mo addition to the standard manganese steel to improve the mechanical properties was investigated at several heat treatment condition. The mechanical properties of the standard manganese steel was raised by addition of Mo.

압전필름 작동기의 패턴최적화를 이용한 평면 음향방출기 설계

황준석,김승조 서울대학교 항공우주신기술연구소 2000 항공우주신기술연구소 연구보고 Vol.1 No.1

In this study, a design method for the flat sound radiator is developed to make new sound radiator system, whose shape is much thinner than that of conventional loudspeaker. Piezofilm(PVDF) is used as actuators of flat sound radiator. To prevent the distortion of sound, the frequency response of radiated sound to be flat is taken as the design objective. The electrode pattern and orientation angle of piezofilm actuator are optimized to satisfy the design objective. The formulation is based on the coupled finite element and boundary element method. Genetic algorithm is used in the optimization process, which is useful in the optimization of discrete design variables. It is noted that the frequency response with optimized piezofilm actuator is made flat enough to satisfy the design objective. For the enhancement of sound power, double-layered piezofilm actuators are also considered. The sound power with double-layered actuator becomes larger than that with single-layered actuator as expected.

AC plasma display panel에서 페닝 방전가스 혼합비 변화에 따른 휘도와 발광효율 향상에 관한 연구

이승준,황호정 중앙대학교 기술과학연구소 2002 기술과학연구소 논문집 Vol.32 No.-

AC PDP에서 사용하는 가스의 혼합비, 압력 페닝 효과를 고려한 가스 조합의 최적화를 통해 낮은 방전전압으로 휘도의 증가를 얻을 수 있는 고휘도, 고효율 PDP 페닝 기체 혼합비를 찾고자 하였다. He(70%)-Ne(27%)-Xe(3%)의 3원 혼합기체와 Ne(96%)-Xe(4%)의 2원 혼합기체에 페닝 효과를 극대화하기 위한 소량의 Ar, Kr을 첨가하여 각각의 첨가비에 따른 방전 개시전압, 방전 유지저압, 휘도, 발광효율등을 측정하였다. 또한 페닝효과에 의한 방전 공간상의 전자수 증가를 확인하기 위해 셀 내의 전극 위에 쌓이는 벽전하 양을 측정하였다. 소량의 Ar(0.01%-0.03%) 또는 Kr(0.01%-0.03%)을 He-Ne-Xe과 Ne-Xe 혼합가스에 참가했을 때 페닝효과에 기인하여 휘도 및 발광효율이 각각 최고 10%-20% 증가하였다. We suggest a new penning gas mixture, in order to find the optimum mixture gas in plasma display panel. The optimum gas composition has been found by the partial pressure of inert gases (such as Ar and Kr added to matrix of He(70%)-Ne(27%)-Xe(3%) and Ne(96%)-Xe(4%). The influences of Ar of Kr addition to Ne(96%)-XE(4%) and He(70%)-Ne(27%)-Xe(3%) mixture gases are experimentally investigated for AC Plasma Display Panel. When rare Ar(0.01%-0.03%) or Kr(0.01%-0.03%) is added Ne-Xe and He-Ne-Xe mixture gases, the luminance increases over 10%-20% and luminous efficiency increases over 10-20% at 200Torr. It is sure that luminance and efficiency are improved by Penning effec.

고정식 교정환자에서 치주건강 유지에 대한 전동치솔의 효과

박성준,황현식,이기헌,경승현 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.2

Patients with fixed orthodontic appliances frequently show ineffective plaque control caused by these orthodontic appliances. Although many methods may be helpful in reducing dental plaque formation, optimal mechanical plaque removal and oral hygiene instruction are the most important factors during orthodontic treatment. The purpose of this study was to evaluate the efficacy of an electric toothbrush, with a specially designed orthodontic brush head, compared to a manual toothbrush on periodontal health in patients with fixed orthodontic appliances. Forty patients were randomly divided into two groups, the electric and the manual toothbrush groups, 1 month after attachment of fixed orthodontic appliances. Periodontal status was measured using a plaque index, a gingival index, a bleeding index, a pocket depth and a relative attachment loss, at baseline and after 3 months, 6 months, 9 months, and 12 months. Oral hygiene instruction was given according to the type of toothbrush used. The Braun Oral-B Plak Control with Ortho OD 15-1 brush was used as the electric toothbrush while the Butler G. U. M 124 was given as the manual toothbrush. By comparing between the electric and the manual toothbrush groups, the following results were obtained: 1. In the manual toothbrush group, the gingival and bleeding indices showed no statistically significant differences. but the plaque index was significantly decreased (p<0.001) and pocket depth as well as relative attachment loss were significantly increased (p<0.01). 2. In the electric toothbrush group, the bleeding index, pocket depth and relative attachment loss showed no statistically significant differences, but the plaque and gingival indices were significantly decreased (p<0.001). 3. In the case of the plaque, gingival and bleeding indices, there were no statistically significant differences between the electric and the manual toothbrush groups. On the contrary, in the case of pocket depth and relative attachment loss, there were statistically significant differences between the electric and the manual toothbrush groups: an increase in the manual toothbrush groups unlike the electric toothbrush groups keeping the same state (p<0.05). These findings suggest that an electric toothbrush is useful to orthodontic patients with fixed appliances.

韓國人에서 pV47-2 多座位 探針로 檢索되는 VNTR 遺傳座位의 對立遺傳子 頻度

鄭宰安,黃迪駿,李昇燮 大韓法醫學會 1994 대한법의학회지 Vol.18 No.1

Individual differences at the level of their DNA sequence have been known to exist throughout the human genome. One of the simplest methods to visualize these DNA polymorphisms consist of the hybridization of a cloned fragment to restriction enzymes-digested DNA from unrelated individuals, and fractionation by agarose gel electrophoresis. The screening of a large number of DNA fragments by this procedure has resulted in the identification of numerous restriction fragment length polymorphisms(RFLPs) corresponding to DNA sequences described from all human genome. The important feature of these size variation is that they are inherited according to the rules of Mendelian genetics. The allele frequency distribution of highly polymorphic VNTR loci had been determined in 113 Korean living over the Seoul metropolitan area. 113 samples from unrelated individuals were digested with Hae Ⅲ restriction enzyme and hybridized with the recombinant DNA probe, pV47-2. By the analysis of DNA fingerprints detected by pV47-2 multi-locus probe, results were obtained as following:. 1. The size range of the DNA fragments detected for the VNTR polymorphism varied from 5,032 to 37,143 base pairs(bp). 2. The number of alleles identified under the experimental conditions (more than 5Kb) used in the study was 62. 3. The mean band-sharing coefficent is 0.18, and the mean probalility that all fragments detected by pV47-2 in individual A are also present in B is (0.18)? = 0.4 ×10?. 4. The mean allele frequency of highly polymorphic VNTR loci dectected by pV47-2 probe is 0.1, and its heterozygosity is 90%. The information obtained can be used for the paternity testing and the analysis of forensic materials.

인유두종 바이러스 양성 및 음성 침윤성 자궁경부암종에서 p53, p21, mdm2 단백의 발현

박인서,한혜승,김태숙,한지영,김준미,주영채,황태숙 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

다발성 외상 후 횡문근융해증 환자에서의 손상초기 급성신부전의 예측인자

문중범,이강현,황성오,이진웅,한병근,최승옥,강성준 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: Acute renal failure(ARF) is a serious complication of rhabdomyolysis after multiple trauma, and may increase morbidity and mortality. The aim of this study was to elucidate predicting factors for the development of ARF induced by rhabdomyolysis at an early stage of multiple trauma. Methods: This prospective, observational study was conducted at the emergency department of a level I trauma center. Patients with acute multiple trauma, whose plasma levels of creatine phosphokinase(CPK) were higher than 1,000 IU, were included in this study. We excluded patients with any history of myocardial infarction, stroke, underlying renal disease, and/or infectious disease. We collected clinical and laboratory data including age, heart rate, mean arterial blood pressure, injury severity score, serum myoglobin, lactic dehydrogenase, creating phosphokinase, and base excess. Collected data were compared between patients who had ARF and patients who did not have ARF. Results: Eighty-eight patients were enrolled in this study. Eighteen patients(20.5%) developed ARF. The injury severity score(ISS)(p=0.001), the base excess(p<0.001), CPK(p=0.003), and myoglobin(p<0.001) were higher in patients with ARF than in patient without ARF. Logistic regression analysis revealed that early predictors for ARF were high ISS, high base excess, high CPK, and high myoglobin. Conclusion: We could identify early predicting factors for acute renal failure induced by rhabdomyolysis, these factors included ISS, serum CPK and myoglobin, and base excess in the arterial blood gas analysis performed at the emergency department.

응급실에서 소아환자의 진정제로서 케타민(Ketamine)의 사용

서정필,박준석,황태식,장석준,김승호 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Ketamine use in emergency room has been increased. It has rapid onset of action and appropriate duration of action. It does not need endotracheal intubation and produces potent analgesia, sedation, and amnesia. The object of this study is to determine the safety and the degree of physician's satisfaction in relation to ketamine use. Materials and Methods: This is a prospective study using protocol. Pediatric trauma patients who need sedation were given IM ketamine(4 ㎎/㎏) and atropine(0.01 ㎎/㎏) in a same syringe. Monitoring of patients was done by EM residents and complications of ketamine use were recorded. Physician's satisfaction was also recorded after the procedure. Results: Intramuscular ketamine was administered 54 times, mainly for laceration repair. Physicians completed protocol for 51 of treated children. The median time for onset of sedation was 6.5±2.4 min, and duration of action was 32.4±10.8 min. Hypersalivation occurred in 9.8%(n=5); random movement 3.9%(n=2), emesis during procedure(n=1), emesis at home(n=1), and transient oxygen desaturation(n=1). All were quickly identified and treated without specific airway management and sequelae. Of 84% of physicians was satisfied with ketamine use for pediatric sedation. Conclusion: Intramuscular ketamine can be administered safely and satisfactorily in emergency room to facilitate pediatric procedures in conjunction with a defined protocol and appropriate monitoring.

엔로플록사신 액제의 닭유래 병원세균에 대한 시험관내 항균효과 시험

윤효인,박병권,조준형,정상희,박경환,장범수,김종춘,황윤환,임종환,이내경,박승춘 충남대학교 수의과대학 동물의과학연구소 2000 動物醫科學硏究誌 Vol.8 No.-

In this study the antimicrobial spectrum and sensitivity of a liquid formulation of enrofloxacin against the major six pathogenic bacteria isolated from the diseased poultry in Korea were evaluated in comparison with ciprfloxacin (CFX), gentamicin (GM) and penicillin (PC). A liquid form of enrofloxacin, a test material and ciprofloxacin showed at least 83% antibacterial activity against all of six test pathogenic microorganisms at the fixed concentration of 10 ㎍/㎖. Gentamicin and penicillin revealed much lower antibacterial activity at the same condition. We evaluated the liquid form of enrofloxacin as having widespread antibacterial spectrum against poultry infections. The liquid form of enrofloxacin showed potent antibacterial activity, with the MIC range being 0.12∼2 ㎍/㎖ against Gram positives, 0.06∼2 ㎍/㎖ against Gram negatives and 0.5∼2 ㎍/㎖ against Mycoplasma spp. These values were equivalent to or somewhat higher than those of ciprofloxacin, but much lower than those of gentamicn and penicillin. This new liquid form of enrofloxacin would find its way in application of mixing with drinking water for the prevention and treatment of diverse infections in chickens.

엔로플록사신 액제의 닭 호흡기 및 소화기 감염증에 대한 예방 및 치료효과

윤효인,박병권,조준형,정상희,박경환,장범수,김종춘,황윤환,임종환,이내경,박승춘 충남대학교 수의과대학 동물의과학연구소 2000 動物醫科學硏究誌 Vol.8 No.-

We evaluated the efficacy of the liquid form of enrofloxacin against poultry respiratory and digestive infections, the major problems in the poultry industry, from diverse diagnosis viewpoints. Results obtained through this study were as follows: 1. The liquid form of enrofloxacin showed good acceptability to poultry owing to no abhorrence to the drug by chickens, which indicated its suitability for mixing in drinking water. 2. The application of the enrofloxacin formulation improved the productivity of the chicken farm to a great extent by lowering the death toll of chicken raised in the farm. 3. The use of the drug shortened the days to the market, and increased the body weight at the time of marketing. 4. Preventive and therapeutic effects of the liquid enrofloxacin were observed higher than ampicillin, a major antibiotic used in poultry farming. From above results, the liquid form of enrofloxacin would find its use for the prevention and treatment of digestive and respiratory infections, let alone the growth promotion and feed efficiency, especially in the chicken farming practice.