시험관내에서 당화시킨 인슐린의 생체내 활성

김성완,김성연,조보연,이홍규,고창순,민헌기,이문규,김철희,민용기,장학철,정대원,배철민 대한당뇨병학회 1990 Diabetes and Metabolism Journal Vol.14 No.2

진동형 분진 최소착화에너지측정장치에서 분진 응집현상이 미치는 영향

정재희,최충석,목연수,최광석,황명환,우인성,Yamaguma, M.,Kodama, T.,Cheung, W.L. 한국산업안전학회 1999 한국안전학회지 Vol.14 No.3

It is widely recognized that Hartmann tube for measuring the minimum ignition energy(MIE) of powder. But It requires long time and operational skills for measuring. As a variety of new fine powders are being produced day by day in industry, Japen has been developing a measurement system which employs a new method to create a dust/air mixture in a miniature combustion box. In this system, by vibration, the powder is successively fed downward through a hopper made up of metal mesh, and then it is formed into a thin, certain-like, dust/air mixture. With this new apparatus, three types of powder-Lycopodium, Anthraquinone, and Polyacrylonitrile-were tested and the data of MIE were compared with those of a conventional apparatus (the Hartmann tube). Two of them agreed satisfactory, but the other, Anthraquinone, showed quite different values. It is guessed that the agglomerations of the powder particles appear because of particle shapes, static-charge and humidity.

저압용 누전차단기의 차단특성 및 그라파이트 분석에 관한 연구

정재희,이덕출,이경섭,최충석,박수홍,김병수 한국산업안전학회 1999 한국안전학회지 Vol.14 No.1

In this paper, we studied cut off characteristics and fire hazard of residual current protective devices(RCD or ELB) for low voltage. The operative time of RCD with grounding resistance was analyzed by using RCD operating tester. The surface structure and composition of insulator were analyzed by using scanning electron microscope(SEM) and energy dispersive x-ray spectroscopy(EDX). The surface of phenol resin showed network structure and void. The spectra shown in EDX analysis are composed not only of the corresponding elements but also of several new spectra, as CK, OKα , MgK, SiK, and CaK, which were absent in original material.

일부 영세 도금사업장의 국소배기성능과 공기중 총크롬 , 6가 크롬 및 니켈농도와의 관계분석

박동욱,박두용,신용철,오세민,정규철 한국산업위생학회 1993 한국산업보건학회지 Vol.3 No.1

To evaluate efficiencies of the local exhaust systems installed in chromium and nickel electroplating tanks, specifications of each tank and general performances of the local exhaust systems were measured in 16 electroplating plants from July 3 to November 24, 1992. Airborne concentrations of total chromium, hexa-chromium and nickel were also measured. Most of the local exhaust systems installed in electroplating plants were inadequately designed. Average capture velocities of local exhaust systems in chromium and nickel tanks were 0.45 m/sec and 0.29 m/sec. Average slot velocities in chromium and nickel tanks were 7.30 m/sec and 2.87 m/sec respectively. Both average capture and slot velocities were in noncompliance with the standards recommended by American Conference of Governmental Industrial Hygienists (ACGIH) and National Institute for Occupational Safety and Health (NIOSH). Exhausted air volume was insufficient in all local exhaust systems surveyed. Worker exposure levels to total chromium, hexa-chromium and nickel were 43.0 ㎍/㎥, 1.7 ㎍/㎥ and 9.3 ㎍/㎥, which were below the Korean Standard and U.S. Occupational Health and Safety Administration (OHSA) Permissible Exposure Limit (PEL). However, Worker exposure level to hexa-chromium exceeded the NIOSH Recommended Exposure Limit(REL) of 1 ㎍/㎥. As the result of Scheffee's multiple comparions, worker exposure levels to all metals were significantly different between two groups by the management state of existing local exhaust systems (p$lt;0.05). However, Difference between a group with local exhaust systems which were poorly managed and another group without local exhaust system was satatistically non-significant.

Mycobacterium Avium - in tracellulare Complex 와 M . Fortuitum 에 의한 폐항산균증(肺抗酸菌症) 3예

김상재,홍수표,배길한,김성진,진병환,정충모 대한미생물학회 1982 大韓微生物學會誌 Vol.17 No.1

Two cases of pulmonary disease in a 54 year-old female and a 70 year-old male patient due to Mycobacterium avium-intracellulare complex (MAIC) and a case of pulmonary infection in a 69 year-old male patient due to M fortuitum (MF) were found recently in this institute. All three patients bad a long history of anti-tuberculous chemotherapy because they were initially diagnosed as pulmonary tuberculosis. A 70 year-old male patient infected with MAIC had an unsuccessful chemotherapy history of isoniazid (INH), para-aminosalicylic acid (PAS) and streptomycin (SM) with an incomplete, temporary, symptomatic improvement, for three years since 1964 when he was first diagnosed as pulmonary tuberculosis on physical examination. A 54 year-old female patient infected with MAIC also had an unsuccessful chemotherapy history with the various anti-tuberculous drugs since 1958. Both patients discharged large number of MAIC in their sputum specimens for at least more than one year, but no M tuberculosis at all. A 69 year-old male patient infected with MF was diagnosed as moderately advanced pulmonary tuberculsis in 1977. Combined chemotherapy with INH+PAS+pyrazinamide (PZA) improved his clinical symptoms, however, his chest radiograph was deteriorated again in 1980 one year after he stopped therapy. Therefore he started chemotherapy again with INH+ethionamide (TH)+cycloserine(CS) but no improvement was noticed. MF was cultured from his sputum in August 1983 and he continuously discharged the same baeilli until last examination of January l982. Whether all three patients were initially infected with nontuberculous mycobacteria or complicated with predisposing tuberculosis was not clear because there were no reliable bacteriological Examination records.

연속주조법으로 제조된 Cu-9Ni-6Sn 합금의 기계적 특성에 관한 연구 : Part 1 . 연주속도 및 냉간 swaging 에 따른 기계적 특성 변화 Part 1 . Effects of Continuous Casting Rates and Swaging

류재철,김상식,김창주,정윤철,한승전 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.8

In the present study, tensile properties of continuous casted Cu-9Ni-6Sn alloy, with and without 95% swaging, were examined as a function of continuous casting rates. A large amount of Sn-rich phases were observed in the interdendritic regions of as-casted Cu-9Ni-6Sn alloy, regardless of casting rates. The size and distribution of these phases, however, differ greatly with different casting rates, as well as the amount of Sn in the phase. Slower casting rate tended to increase the size of the phase, but the amount of Sn in the phase increased with faster casting rate. During solutionization, most of Sn-rich phase appeared to decompose into the solid solution. After aging, a significant amount of coarse precipitates were observed in the alloy produced at a casting rate of 280 ㎜/min. It is believed that such coarse precipitates were formed around the Sn-rich phases due to relatively high Sn content after solutionization. SEM fractographic studies indicated that coarse precipitates, as well as weak Sn-rich phases, act as sources for microvoid. Consequently, both tensile strength and elongation of solutionized and aged Cu-9Ni-6Sn alloy increased significantly with decreasing casting rate. Cold swaging greatly improved the tensile properties of Cu-9Ni-6Sn alloy due to the reduced and refined Sn-rich phases and coarse precipitates.

EPS 공정의 정량적 위험성 평가를 통한 안전의사결정에 관한 연구

정재희,김형석,최광석,이영순 한국산업안전학회 1999 한국안전학회지 Vol.14 No.2

The quantitative risk assessment and consequence analysis by accident scenario in the process of EPS(Expendable Poly Stylene) reaction process are conducted. And the decision making process is studied followed by selecting various alternatives to safety management and facility improvement. The result are as follows; 1) The object of decision making through comprehensive risk assessment are the scenario which can cause four major accident, which are made by process analysis, work analysis and hazard identification. 2) Frequency analysis of ETA, FTA, HRA and consequence analysis of accident to each have been conducted. The each frequency values are yielded 9.2×10^(-5)/yr to scenarios 1, 8.2×10^(-4)/yr to scenario 2, 4.5×10^(-6)/yr scenario 3 and 1.8×10^(-7)/yr to scenario 4. The each scenarios have been conducted consequence analysis. 3) The calculated values have been obtained 4.00 to scenario 1, 3.25 to scenario 2, 2.43 to scenario 3 and 1.34 to scenario 4, as the weight value had been applied to the quantitative and normalized criteria of all components. As a risk criteria, scenario 1 have been selected, which is the most dangerous scenario as a result of ranking the scenario. 4) According to the importance of FTA and contribute to scenario 1, the cost-benefit values are yielded 8.05×10^5[￦/yr] to final alternative(A1), 1.55×10^5[￦/yr] to final alternative(A2) and 2.32×10^5[￦/yr] to final alternative(A3). As a result of final alternative(A1) has been selected, which is the most optimized alternative.

당뇨병성(糖尿病性)족부병변(足部病變)의 임상적관찰

이홍규,민헌기,이문규,정민화,원암우,김성연 대한당뇨병학회 1984 Diabetes and Metabolism Journal Vol.8 No.1

수평방향의 정현파 가진을 받는 강체 블록의 비선형 로킹진동특성

김지훈,김정호,양인영,정낙규,정만용 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

This research concentrates on the influence of non-linearities associated with impact for the nonlinear rocking behavior of rigid block subjected to one dimensional sinusoidal excitation of horizontal direction. The transition of two governing rocking equations, the abrupt reduction in the kinetic energy associated with impact, and sliding motion of block. In this study, two type of rocking vibration system are considered. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation and sliding motion. The response analysis using non-dimensional rocking equation is carried out for the change of excitation parameters and friction coefficient. The chaos responses were discovered in the wide response region, particularly, for the case of high excitation amplitude and their chaos characteristics were examined by the time history, Poincare map, power spectra and Lyapunov Exponent of rocking responses. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. The bifurcation diagram and Poincare map were shown to be effective in order to understand chaos of rocking system.

건식 열화처리가 FRP 의 표면 열화와 유전특성에 미치는 영향

이덕출,이백수,정의남,유도현,김종택 한국산업안전학회 1998 한국안전학회지 Vol.13 No.3

In this paper, we investigated the change of wettability, surface potential decay and dielectric properties caused by ultraviolet-treated, thermal-treated and discharge-treated FRP(fiber reinforced plastics) respectively for finding out: the influence of dry treatments effected to electrical characteristics on the surface of polymer composites. For the change of wettability, the contact angle of thermal-treated specimen with the high temperature of 200℃ increased. But that of UV-treated and discharge- treated specimen decreased. The characteristic of surface potential decay shows the tendency of the remarkable decrease on UV-treated and discharge-treated specimens, but no difference on thermal-treated specimen compared with untreated one. Also, for the dielectric properties, it shows the increase at large on the treated specimens and especially, the remarkable increase on thermal-treated one.