TMA wire로 제작된 3종류의 MVLAW(Multi-Vertical Loop Arch Wire)의 초기응력분포에 관한 광탄성학적 연구

이형철,전윤식 대한치과교정학회 1995 대한치과교정학회지 Vol.25 No.1

교정치료시 치축의 개선을 위한 많은 연구와 노력이 이루어져 왔다. 본 교실에서는 치축개선을 위해 MEAW를 응용한 Multi-Vertical Loop Arch Wire(MVLAW : 엠빌로)를 수년 전부터 다수치아의 치축을 동시에 개선코자 사용해 왔다. MVLAW는 일종의 근심경사된 치아를 세우는 장치로써 open vertical loop를 3가지 종류로 변형시켜 적용시켜 왔으며 이를 각각 A, B, C형으로 명명하였다. 각 MVLAW는 .017˝×.025˝ TMAwire로 제작외면, A형 MVLAW의 경우 각 open vertical loop의 apex를 10도 정도 벌려주어 활성화시키며(electric welding stop을 각 loop의 근심측에 위치시킨다), B형과 C형 MVLAW의 경우 open vertical lop의 원심측에 10도의 tip back bend를 형성함으로써 활성화시킨다(B형의 경우 electric welding stop이 각 loop의 원심측에 형성되는 반면 C형의 경우 electric welding stop을 형성하지 않는다). 본 연구는 구치부의 치축을 동시에 개선코자할 때 MVLAW를 3가지 종류로 분류한 후 각 MVLAW의 효과를 알아보고자 상하악 1/2약을 광탄성 모형에 재현하여 그 응력분포를 관찰하여 다음과 같은 결론을 얻었기에 보고하는 바이다. 1. A형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 하악 제1대구치와 제2대구치 치근의 원심면에서 강한 응력분포를 나타내나 전치부에 발생한 미약한 응력분포는 3급 견인고무의 장착으로 상쇄되었다. 따라서 A형 MVLAW는 초기에 치관의 직립효과가 있는 것으로 보인다. 2. B형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 각 치아의 근심측에 응력분포를 보이며 견인고무를 걸었을 때와 비교시 전치부에 증가된 응력분포를 보였다. 따라서 B형의 경우 초기에 치근의 직립효과가 있는 것으로 보인다. 3. C형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 하악전치부를 제외하고는 응력분포를 나타내지 않았으나 견인고무를 걸었을 경우 주로 견치와 소구치 근심면에서 응력분포를 보였다. 따라서 C형의 경우 견인고무 사용시 초기에 견치와 소구치에서 치근의 직립효과가 있는 것으로 보인다. Multi-Vertical Loop Arch Wire(MVLAW) is a kind of appliance for uprighting the mesially inclined posterior teeth axes simultaneously. In this study MVLAW was classified as 3 types by modifing the vertical loop design and named type A, B and C. Each MVLAW was fabricated from .017˝×.025˝ TMA wire and preactivated at the distal end of the open vertical loop with 10 degree tip-back bend(type B has an electric welding stop at the distal end of each loop ad type C has no electric welding stop). Type A MVLAW was preactivated at the apex of each open vertical loop with 10 degree tip-back bend(the electric welding stop of type A is positioned at the mesial side of each loop). The aim of the present study was to identify when and which MVLAW is more effective to correct the buccal segment axed simultaneously. The photoelastic overview of the upper and lower right quadrant showed that stress concentrations were observed in its photoelastic model. The obtained results were as follows : 1. Higher level compression can be seen clearly at the distal curvature of the lower 1st and 2nd molar when A type MVLAW was applied without short class Ⅲ elastic, but mild compression cannot be seen at the distal curvature of lower anterior teeth using the class Ⅲ elastic. 2. Higher concentration was presented at the mesial curvature from the lower 1st premolar to the 2nd molar than the anterior teeth when B type MVLAW without short class Ⅲ elastic was applied, but using the short class Ⅲ elastic, higher concentration of compression was presented in the anterior teeth area. 3. Areas of higher compression and tension were not observed at the mesial and distal curvature of the entire lower teeth except lower central lateral incisors in C type MVLAW without short class Ⅲ elastic, but using the short class Ⅲ elastic, higher concentration was seen at the mesial curvature of the lower 1st premolar and lower anterior teeth.

포사맥스 정(알렌드론산나트륨 70mg)에 대한 대웅 알렌드로네이트 정 70mg의 생물학적 동등성

이예리,정선경,양승권,최기호,신용철,전형규,강승우,이희주 한국약제학회 2006 Journal of Pharmaceutical Investigation Vol.36 No.2

바닥상태 및 들뜬상태에서 날리딕산 수용액의 해리에 관한 연구

성아영,이형철 대불대학교 1999 論文集 Vol.5 No.1

The ionization structure and ionization constant of nalidixic acid have been studied in the ground-and excited states at room temperature. The nalidixic acid has two chromophore in aqueous solution and the hydrogen atom combined in the carboxyl group of the molecule was dissociated in the aqueous solution. The ionization constant of nalidixic acid in the ground state was determined by spectrophotometric method and by potentiometric titration method. The pKa value of the substance was found to be 6.35 in aqueous solution. In the excited state, it was found to be 1.75. This result indicates that dipole moment of the molecule increased in the excited state very much rather than in the ground state.

메타올-암모니아 혼합용액의 광반응에 미치는 산소의 영향에 관한 연구

성아영,이형철,김희정 대불대학교 1999 論文集 Vol.5 No.1

The photochemical reaction of ammonia in aqueous methanol have been investigated by using 184.9 nm UV light at 25 ℃. During the photochemical reaction of methanol-ammonia mixture solution (mole fraction = 0.10 : 5×10-4), carbonyl compounds such as formaldehyde, ethyleneglycol and glyoxal, and amine compounds such as methoxyamine, 1,1-dimethlyhydrazine and dimethylamine were produced along with minor products such as ethlyenediamine and hydrazine. The presence of oxygen affected to the photochemical reactions. The reaction probability of hydrogen radicals with both methanol and ammonia decreased in the presence of oxygen because hydrogen radicals reacted with oxygen in the air atmosphere, resulting in the decrease of Initial quantum yield.

염색 단판을 이용한 集成 染色 무늬목 開發

안삼근,강형철,안상열,이균필,변희섭 경상대학교 농업생명과학연구원 2002 농업생명과학연구 Vol.36 No.4

본 연구는 집성 염색 무니목 개발을 위하여 사용 가능한 수종과 3종류의 염료를 사용하여 염색시간, 염색온도, 함수율 및 Flitch 제작에 대하여 연구한 결과는 다음과 같다. 실험에 사용한 4수종 중에서 선삭성이 불량한 은수원 사시나무를 제외한 3수종인 소나무와 이태리 포플러, 마티카가 사용 가능한 수종으로 밝혀졌다. Stain은 번지거나 얼룩이 지는 현상, Dylon은 침투 불균일로 부적당하였으나 Fine은 염색상태가 양호하였다. 염색시간은 5시간 이상 되어야 염색정도가 양호하였고, 염색온도는 90℃에서 가장 적당하였으며 생재와 기건재 및 포수재에 대한 영향은 큰 차이가 없었다. Flitch제작에 적당한 함수율은 9%이었다. This study was carried out to develop laminated dyeing wood, for which usable three sixties of trees and 3 kinds of dye stuffs were used to investigate dyeing time, dyeing temperature, moisture content and manufacture of flitch, the results were as follows: Out of four species of trees used in the experiment, it was found that three species, Pinus densiflora, Populus euramercana and Dyrea costulata were usable excluding Populus tomentiglandulosa whose cutting ability was bad. As to influence according to the kind of dye stuff, the Stain of low price could be used as a coloring agent but it was not proper as a dyeing agent due to spreading or staining phenomenon. As Dylon which was generally used to dye textile penetrated them uneven, dyeing only their surface, it was also found improper to be used. On the other hand, the dyed condition was good with Fine. The dyed condition was good when dyeing time was more than 5 hours and it was the most adequate when the temperature was at 90℃. There was no significant difference between their influence on green, dried and saturated wood.-In the manufacture of Flitch, the most appropriate moisture content was 9%.

고립성 폐결절의 조직학적 진단에 있어서 경기관지폐생검의 진단적 가치

김치훈,김정주,왕준호,연규민,김형수,리원연,용석중,신계철 건국대학교 의과학연구소 2002 건국의과학학술지 Vol.12 No.-

Transbronchial lung biopsy(TBLB) is a relatively simple and convenient diagnostic tool in solitary pulmonary nodule(SPN) on chest radiograph, which is cannot be diagnosed through routine tests. To investigate the diagnostic value and diagnostic rate of TBLB according to the variable factor, we analyzed 69 patients with radiologically SPN lesion on chest radiograph which was confirmed histologically. A histologic diagnosis of TBLB was made in 47 of 69 patients(68.1%), in which 26 of 37(70.3%) with malignancy and 21 of 32(65.6%) with benign lesion. There were no significant differences in diagnostic yield according to age, sex and location of the lesion. The diagnostic rate tended to increase with the more than 5 pieces to acquired by TBLB. When the size of SPN was less than 3 ㎝, it cannot be diagnosed. In conclusion, TBLB is a diagnostic procedure with good yield and safety, but percutaneous needle aspiration, transbronchial needle aspiration, and bronchial washing fluid cytology may be a complementary procedure to overcome the limitation of TBLB and get higher diagnostic yield for SPN.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

A study on the generation method of effectiveness data for surface to surface artillery system - Focused on the effective evaluator prototype of high explosive -

Hyeong-Chul Lee,Da Hoon Lim,Yeong-Chul Kim 한국콘텐츠학회 2021 한국콘텐츠학회 ICCC 논문집 Vol.2021 No.12

Hair Growth-Promoting Effects of Lavender Oil in C57BL/6 Mice

Lee, Boo Hyeong,Lee, Jae Soon,Kim, Young Chul Korean Society of ToxicologyKorea Environmental Mu 2016 Toxicological Research Vol.32 No.2

The purpose of this study was to determine the hair growth effects of lavender oil (LO) in female C57BL/6 mice. The experimental animals were divided into a normal group (N: saline), a vehicle control group (VC: jojoba oil), a positive control group (PC: 3% minoxidil), experimental group 1 (E1: 3% LO), and experimental group 2 (E2: 5% LO). Test compound solutions were topically applied to the backs of the mice ($100{\mu}L$ per application), once per day, 5 times a week, for 4 weeks. The changes in hair follicle number, dermal thickness, and hair follicle depth were observed in skin tissues stained with hematoxylin and eosin, and the number of mast cells was measured in the dermal and hypodermal layers stained with toluidine blue. PC, E1, and E2 groups showed a significantly increased number of hair follicles, deepened hair follicle depth, and thickened dermal layer, along with a significantly decreased number of mast cells compared to the N group. These results indicated that LO has a marked hair growth-promoting effect, as observed morphologically and histologically. There was no significant difference in the weight of the thymus among the groups. However, both absolute and relative weights of the spleen were significantly higher in the PC group than in the N, VC, E1, or E2 group at week 4. Thus, LO could be practically applied as a hair growth-promoting agent.

GOTHIC-3D APPLICABILITY TO HYDROGEN COMBUSTION ANALYSIS

LEE JUNG-JAE,LEE JIN-YONG,PARK GOON-CHERL,LEE BYUNG-CHUL,YOO HOJONG,KIM HYEONG-TAEK,OH SEUNG-JONG Korean Nuclear Society 2005 Nuclear Engineering and Technology Vol.37 No.3

Severe accidents in nuclear power plants can cause hydrogen-generating chemical reactions, which create the danger of hydrogen combustion and thus threaten containment integrity. For containment analyses, a three-dimensional mechanistic code, GOTHIC-3D has been applied near source compartments to predict whether or not highly reactive gas mixtures can form during an accident with the hydrogen mitigation system working. To assess the code applicability to hydrogen combustion analysis, this paper presents the numerical calculation results of GOTHIC-3D for various hydrogen combustion experiments, including FLAME, LSVCTF, and SNU-2D. In this study, a technical base for the modeling oflarge- and small-scale facilities was introduced through sensitivity studies on cell size and bum modeling parameters. Use of a turbulent bum option of the eddy dissipation concept enabled scale-free applications. Lowering the bum parameter values for the flame thickness and the bum temperature limit resulted in a larger flame velocity. When applied to hydrogen combustion analysis, this study revealed that the GOTHIC-3D code is generally able to predict the combustion phenomena with its default bum modeling parameters for large-scale facilities. However, the code needs further modifications of its bum modeling parameters to be applied to either small-scale facilities or extremely fast transients.