제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

機械加工品의 最適加工速度에 關한 硏究

成煥泰,吳澤烈,吳煥燮 慶熙大學校 1980 論文集 Vol.10 No.-

In this study, the optimum mathematical models were made in order to derive Optimum Machining speed which is due to be established in the production of each manufactures as an important parameter based upon the cutting speed, in case of making manufactures of multi-kinds into unit-production processing. The economical optimum cutting speed has been set up by using the above phenomenon as a proper system, and the results from the comparative analysis between the above model & the actual cutting work data, are summarized as follows. (1) The mathematical models for the optimum machining speed are derived into the expressions (23), (24), (25), (26), (27), (28), (29). (2) The basic expressions of the optimum machining speed are derived into (32), (34), (36), (37), (39), (40), (41), (44), for the purpose of each estimation of the maximum efficiency standard, the minimum cost standard and the maximum profits rate standard. (3) The example of setting up the optimum cutting speed of multi-kinds manufacturing production was formulated, and the experimental theoretical values were known to be in the same range as a result of the comparative study between the cutting speed obtained by the cutting test & the optimum cutting speed calculated by the theoretical expressions.

한 종합병원 암등록환자에 대한 통계적 고찰

오성균,심운택,이태용 충남대학교 의과대학 지역사회의학연구소 1988 충남의대잡지 Vol.15 No.2

This study was conducted with 1, 073 patients who registered at cancer registry of Chungnam National University Hospital for the year of 1981, 1983, 1985 and 1987 to fird out the general characteristics of cancer incidence according to sex, age, residential area and season for the important organs. The results were as follows: 1. The sex ratio of cancer was higher in male than female as 1.3 : 1. 2. The age group of over 40 years occupied 80% or more of total cases. 3. The cancer incidence of stomach, lung, larynx, lymph node were high in male and in female, the cancer of uterine cervix, stomach, breast, thyroid were high in that order. 4. The relative frequency by age group showed that the cancer of stomach, lymph node, thyroid, uterine cervix were high in less 29 years of age and the cancer cf stomach, lymphnode, thyroid, lung were high in 30-39 years of age and the cancer of stomach, lung, uterinecervix, larynx were high in over 50 years of age in that order. 5. There was no difference in cancer incidence by residential area and season. 6. The median survival time of cancers were 10.5 months in stomach cancer, 14.0 monthe in uterine cervix cancer, 7.0 months in lung cancer. 7. The 5 year survival rate of cancers were 76.9% in uterine cervix cancer, 52.8% in stomach cancer, 19.4% in lung cancer.

관절성형술 및 측두근막 이식술을 이용한 악관절 강직증의 치험례

진택현,오승환,류동목,김여갑,이상철 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.1

This is a case of bony ankylosis of right temporomandibular joint with mild facial asymmetry resulted from trauma, which bring about the right condylar fracture, and corrected by interpositional arthroplasty with temporal fascia flap and coronoidectomy. The postoperative results were functionally and esthetically good, but continued osbervation is necessary to evaluation of abnormal bony growth and reankylosis.

Grade 2, 4 티타늄 마이크로 임플랜트의 식립 및 제거 토크와 식립 후 조직학적 반응의 비교

강승택,권오원,성재현,경희문,박효상 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.3

마이크로 임플랜트는 순티타늄과 티타늄 합금을 사용하고 있다. 순티타늄의 경우 grade가 낮을 수록 생체적합성은 증가하나 기계적 성질이 낮다. 이에 본 연구에서는 순티타늄 grade 2와 grade 4를 재료로 한 마이크로 임플랜트를 각각 토끼의 다리뼈에 식립한 후 2, 8, 12주의 시간경과에 따른 조직학적 소견의 차이와 식립, 제거 시의 최대토크의 측정으로 그 티타늄 종류에 따른 차이를 살펴보았다. 토끼의 경골에 식립한 티타늄의 종류에 따른 식립시 및 시간의 경과에 따른 제거시의 토크를 측정하여 다음과 같은 결론을 얻었다. 첫째, grade 2와 grade 4간의 식립 시 최대토크의 차이는 없었다. 둘째, 식립 후 2, 8, 12주 후의 제거 시 최대토크 측정에서 전체 마이크로 임플랜트의 그룹간 차이는 없었다. 셋째, 2주에서 8주로 시간이 경과함에 따라 제거 시 최대토크가 유의하게 증가하였으며 8주와 12주간에는 유의한 상관관계가 없었다. 따라서 유지력은 grade 2 티타늄과 비슷하지만 물리적 성질이 더 단단한 grade 4 티타늄을 마이크로 임플랜트 재료로 사용하는 것이 좋은 것으로 생각된다. The purpose of this study was to evaluate the light microscopic features and the maximum insertional and removal torque value of microimplants, made from titanium grade 2 or 4, in the tibia of 6 rabbits. First, the maximum torque values of microimplants at implantation were measured. After 2, 8, and 12 weeks of healing time, the microimplant-containing segments of tibia of 2 rabbits were removed and the maximum removal torque of each microimplant were measured. Comparisons of histologic examination and insertional and removal torque values were carried out for the two groups of microimplants. Removal torque values were significantly increased in both groups after 8 and 12 weeks as compared to 2 weeks after implantation. Other values measured did not show any statistically significant differences and there were no histological differences between grade 2 and 4 titanium. Based on these results, this study showed that there were no significant differences between grade 2 and 4 titanium. It seems better to use grade 4 titanium for making microimplants because grade 4 titanium is mechanically harder than grade 2 titanium and has similar retention.

都市地域住民의 生活體育 意識構造

鄭相澤,吳東燮,安禹洪,金正子,林銖遠 慶北大學校 體育科學硏究所 1991 체육과학연구지 Vol.7 No.-

This study was aimed to elucidata Taegu citizens' consciousness about Sport for All. 950 subjects responded to the researcher's questionnaires. The results are as follows; 1) 88.8% of whole subjects felt necessity of physical activity in every day life. In view of sex, 91.0% of male and 86.5% of female felt the necessity. 2) 73.4% of the subjects put weight in health improvement and 19.1% of the subjects put weight in strong mental power in relation to the value of physical activity. 3) About the local facilities of physical activity, only 8.3% of the subjects satisfied. A largy majority(65.7%) of the subjects reveated dissatisfaction. 4) Preference orders in relation to the expansion of facilities appeared as follows; tennis court(24.5%), swimming pool(14.4%), badminton court(12.5%), gymnasium(11.4%) and football field(7.0%). 5) 76.1% of the sujbjects thought that physical activity contribute to reduce demoralized life style, but 3.2% of the subjects not thought so. 6) About present participation in physical activity, 31.8% of the subjects answered being participated, but the large majority(68.2%) of the subjects answered not being participated. 7) Subjects' favorite physical activitier are tennis(18.6%), mounteering (12.9%), football(8.9%), golf(8.6%), badminton(8.3%), jogging(8.3%), gymnasics(7.3%) and swimming(7.0%) 8) The places of physical activities are private facilities(33.4%), work place(13.6%), private house(12.6%), school(10.9%) and physical education park(9.3%). 9) 73.9% of the subjects answered that they were participating in physical activity for health improvement. 10) 70.6% of the subjects felt the necessity of coach of Sport for All. 11) In case of not attendance to the physical activity, 70.6% of them answered that the main reason of not attendance was lack of leisure. 12) In case of not attendance, 33.7% of them spared time to TV watching, 28.8% of them to housework and 18.0% of them to sleeping. 13) 13.5% of subjects wanted to participate in swimming, 12.9% to tennis, 11.7% to table tennis, 10.8% to mountaineering, and 10.3% to badminton if circumstances permit.

볼나사 지지 구조와 베어링 조합 배열에 관한 연구

홍성오,정성택,조규재 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.3

In order to achieve high precision machine tools, Performance enhancement of feed drive systems is required. One of the important technical issues is how to decrease thermal expansion of ball screw in proportion to the increase of machining speed. When measuring force of stretch of ball screw, since not only actual expansion and the value of bending have to be considered, it is impossible to define the exact value of expansion. In addition, support bearings of ball screw gain considerable force in axial direction. It also generates thermal expansion on the ball screw, and deteriorates the performances of the bearings. In conclusion, it is impossible to give the pretension enough to absorb all the elongation due to thermal expansion generated during machine is running. If give, bed column and saddle are all bent to change machine accuracy, and the support bearings of ball screw is damages.

상악 제3대구치 발거후 발생한 광범위한 피하기종

이은택,민승기,오승환,이동근 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.1

Subcutaneous air emphysema is a relatively uncommon phenomenon. It has been reported in both the medical and dental literature following such various procedures as rectal biopsy, nasogastric intubation, radical neck dissection, tonsillectomy, adenoidectomy, root canal treatment, dental restoration and extraction of maxillary and mandibular teeth. The most common cause involves extraction of mandibular third molar. Subcutaneous emphysema of the head, neck and thorax is a swelling caused by introduction of air into the space of the connective tissue. The clinical signs are local swelling, tenting of the skin, and crepitation on palpation. In extreme casesk, air has been reported to pass through the masticatory space into the parapharyngeal and retropharyngeal space, and penetrate into the mediastinum. If the inflowing air contains bacteria, serious infection may ensue. The first case of subcutaneous emphysema associated with a dental procedure was first reported in 1900. This emphysema is a often limited only to the spaces of head and neck, but also can involve deeper structure. This case is diffuse subcutaneous emphysema following maxillary third molar extraction with a high-speed drill.

불수의 운동형뇌성마비환자의 음성학적 특징

이지인,오상호,이양수,김풍택 大韓再活醫學會 2000 Annals of Rehabilitation Medicine Vol.24 No.4

교정장치로부터의 니켈과 크롬의 유리에 관한 연구

류정현,오소택,강경화,김상철 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.5

니켈과 크롬은 대부분의 교정장치를 제작하는데 사용되는 합금을 구성하는 주요한 금속이다. 그러나 이들 금속은 과민반응, 피부염, 천식 등의 주요한 원인이 되며, 이들 금속의 우발적인 흡입에 의해 암이 유발될 수 있음이 보고된바 있다. 이에 하악 standard edgewise 브라켓을 이용한 사분악의 교정 장치를 37℃, 0.05% NaCl 용액에 저장하여 교정장치의 부식에 의해 유리된 니켈과 크롬을 Inductively Coupled Plasma(ICP) spectroanalyzer를 이용하여 측정하였다. 교정장치로부터, 1일 평균 9.83-70.0㎍/day의 니켈이 유리되었으나, 크롬은 10ppb 측정한계에서 측정불가능 하였다. 니켈 유리량은 제품에 따라 유의한 차이를 가져왔다. Galvanic 조건이나 Sand blasting 처리는 니켈 유리량에 증가를 가져왔으나 통계학적으로 유의하지 않았다. Nickel and chromium are two major metals used in the alloys of most orthodontic appliances. But these metals arc known to cause hypersensitivity, dermatitis, and asthma. In addition, a significant carcinogenic and mutagenic potential has been demonstrated for compounds containing these metals. The purpose of this study was to find out how much nickel and chromium was released from orthodontic appliances, and which factors would influence the release. The simulated orthodontic appliances were constructed for a half of a mandibular arch and incubated in 0.05% NaCl solution at 37℃. Nickel and chromium release was quantified with an Inductively Coupled Plasma (ICP) spectroanalyzer. The results were as follows 1. From simulated orthodontic appliances, nickel was released 9.83-70.0㎍/day but the release of chromium was not detectable in limit of l0ppb. 2. The amount of nickel release was significantly different between the types of appliances. 3. The galvanic condition increased the amount of nickel release, which was not statistically significant. 4. The sand blasting increased the amount of nickel release, which was also not statistically significant.