• 한국안전학회지
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• 제27권5호
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• pp.70-76
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• 2012

For the safe handling of n-tetradecane, the lower flash points and the upper flash point, fire point, AITs (auto-ignition temperatures) by ignition delay time were experimented. Also lower and upper explosion limits by using measured the lower and upper flash points for n-tetradecane were calculated. The lower flash points of n-tetradecane by using closed-cup tester were measured $104^{\circ}C$ and $112^{\circ}C$. The lower flash points and fire point of n-tetradecane by using open cup tester were measured $113^{\circ}C$ and $115^{\circ}C$, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-tetradecane. The experimental AIT of n-tridecane was $207^{\circ}C$. The calculated lower and upper explosion limit by using measured lower $104^{\circ}C$ and upper flash point $140^{\circ}C$ for n-tetradecane were 0.63 Vol.% and 3.18 Vol%.

• 한국안전학회지
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• 제28권4호
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• pp.53-57
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• 2013

For the safe handling of n-pentadecane, the lower flash points and the upper flash point, fire point, AITs(auto-ignition temperatures) by ignition delay time were experimented. Also lower and upper explosion limits by using measured the lower and upper flash points for n-pentadecane were calculated. The lower flash points of n-pentadecane by using closed-cup tester were measured $118^{\circ}C$ and $122^{\circ}C$. The lower flash points and fire point of n-pentadecane by using open cup tester were measured $126^{\circ}C$ and $127^{\circ}C$, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-pentadecane. The experimental AIT of n-pentadecane was $195^{\circ}C$. The calculated lower and upper explosion limit by using measured lower $118^{\circ}C$ and upper flash point $174^{\circ}C$ for n-pentadecane were 0.54 Vol.% and 6.40 Vol.%.

• KIEAE Journal
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• 제7권6호
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• pp.37-43
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• 2007

Discomfort glare is an important factor influencing appraisal for lighting environment. Unified Glare Rating (UGR) which has been proposed by CIE is one of the formula for evaluating discomfort glare. Position index is an important factor in the UGR formula. Position index was proposed by Guth in 1949. It has been used until present limiting upper visual field. Lower visual field has different sensation of brightness in comparing with upper visual field. Therefore, it is necessary to propose position index about lower visual field. The objective of this study is to investigate the brightness sensation in upper and lower visual field. First, the visual field was measured on the self-made Glare Tester. Second, luminance of the Borderline between Comfort and Discomfort (BCD) was measured on the glare Tester. Circular sources of brightness were located at various angular distances from the line of vision along five meridians, $0^{\circ}$, $45{\circ}$, $90{\circ}$, $-45{\circ}$, $-90{\circ}$. The size of the glare source is 0.0011sr. The luminance of the surrounding field, which extended over the entire visual field, was maintained $34ccd/m^2$. Ten subjects aged from 25 to 29 were participated in the experiment. The results show that the luminance of BCD on the line of vision is $4337cd/m^2$ and the glare sensation of the lower visual field is more sensitive than the upper visual field.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.1-5
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• 2019

This study has been focused on properties of surface technology for large diameter upper electrode using in high density plasma process as like semi-conductor manufacturing process. The experimental studies have been carried out to get mirror surface for upper electrode. For a formation of high surface quality upper electrode, single crystal silicon upper electrode has been mechanical and chemical machining worked. Mechanical machining work of the upper electrode is carried out with varying mesh type using diamond wheel. In case of chemical machining work, upper electrode surface roughness was observed to be strongly dependent upon the etchant. The different surface roughness characteristics were observed according to etchant. The machining result of the surface roughness and surface morphology have been analyzed by use of surface roughness tester, laser microscope and ICP-MS.

• 한국화재소방학회논문지
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• 제24권2호
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• pp.76-81
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• 2010

톨루엔의 안전한 취급을 위해서 $25^{\circ}C$에서 폭발한계와 폭발한계 온도의존성을 고찰하였다. 또한 인화점과 최소발화온도를 측정하였다. 공정의 안전을 위해서 톨루엔의 폭발하한계는 1.13vol%, 상한계는 7.9vol%를 추천한다. 유통법에 의한 하부인화점은 $5^{\circ}C$, 상부인화점은 $40^{\circ}C$로 측정되었으며, Setaflash 장치에 의한 상부인화점은 $41.5^{\circ}C$로 측정되었다. ASTM E659-78 장치에 최소자연발화온도는 $547^{\circ}C$로 측정되었다. 그리고 톨루엔의 새로운 폭발한계 온도의존식을 제시하였으며, 제시한 온도의존식은 문헌값과 일치하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.149-154
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• 2001

In case of high capacity load force as millions of tons, it is difficult to measure the force with load cell. But we can measure and calculate the force with applied pressure and ram area of hydraulic jack. The 5,200 ton compression load tester is composed of thirteen hydraulic jack with 400 ton capacity. This paper explains the method of measuring the vertical compression load and provides characteristics of unit jack, and displacement of upper structure under maximum load condition.

• 한국화재소방학회논문지
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• 제26권2호
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• pp.84-89
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• 2012

노말노난올의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였고, 인화점과 발화지연시간에 의한 발화온도를 측정하였다. 그 결과, 노말노난올의 폭발하한계는 0.80 Vol.%, 상한계는 6.1 Vol.%를 추천하였고, 하부인화점은 밀폐계에서 $94{\sim}97^{\circ}C$와 개방식에서 $103{\sim}104^{\circ}C$로 측정되었다. ASTM E659-78 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 노말노난올의 최소자연발화온도는 $270^{\circ}C$로 측정되었다.

• 한국가스학회지
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• 제17권4호
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• pp.70-76
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• 2013

스티렌의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였고, 인화점과 발화지연시간에 의한 발화온도를 측정하였다. 그 결과, 스티렌의 폭발하한계는 0.9 Vol.%, 상한계는 8.0 Vol.%를 추천하고, 밀페식 장치에 의한 스티렌의 하부인화점은 $29^{\circ}C{\sim}31^{\circ}C$로 측정되었으며, 개방식에서는 $32^{\circ}C{\sim}36^{\circ}C$로 측정되었다. ASTM E659 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 스티렌의 최소자연발화온도는 $460^{\circ}C$로 측정되었다.

• 한국융합학회논문지
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• 제9권10호
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• pp.423-432
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• 2018

본 연구는 볼링 선수의 상해 경험과 유형에 따라 상 하지 근력과 좌우 비대칭 차이를 살펴보고자 하였다. 본 연구 대상자는 상지 상해 경험 집단(upper body injury group, [UG], n=16)과 하지 상해 경험 집단(low body injury group, [LG], n=8), 상해 미경험 집단(non injury group, [NG], n=15)으로 선정하였다. 볼링 선수의 상 하지 근력은 Manual Muscle Tester 01165 (Lafayette Instrument Company, USA)로 등척성 최대 근력(Isometric strength)을 측정하였으며, 비대칭 지수(symmetry index, [SI])를 산출하였다. 그 결과는 다음과 같다. 하지 근력의 좌우 비대칭 지수는 엉덩관절의 신전과 외측회전 최대근력에서 상해 무경험 집단이 하지 상해 경험 집단에 비하여 통계적으로 크게 나타났다(p<.05). 위 결과를 통하여 하지 근력의 좌우 대칭이 하지 상해와 밀접한 관련이 있다고 판단되며, 상해 예방을 위해 하지 근력의 좌우 대칭 훈련이 필요할 것으로 판단된다.

• 한국안전학회지
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• 제33권4호
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• pp.8-14
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• 2018

In the industrial chemical process involving combustible materials, reliable safety data are required for design prevention, protection and mitigation measures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. The combustion parameters necessary for process safety are lower flash point, upper flash point, fire point, lower explosion limit(LEL), upper explosion limit(UEL)and autoignition temperature(AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. In the chemical industries, tetralin which is widely used as a raw material of intermediate products, coating substances and rubber chemicals was selected. For safe handling of tetralin, the lower and flash point, the fire point, and the AIT were measured. The LEL and UEL of tetralin were calculated using the lower and upper flash point obtained in the experiment. The flash points of tetralin by using the Setaflash and Pensky-Martens closed-cup testers measured $70^{\circ}C$ and $76^{\circ}C$, respectively. The flash points of tetralin using the Tag and Cleveland open cup testers are measured $78^{\circ}C$ and $81^{\circ}C$, respectively. The AIT of the measured tetralin by the ASTM E659 apparatus was measured at $380^{\circ}C$. The LEL and UEL of tetralin measured by Setaflash closed-cup tester at $70^{\circ}C$ and $109^{\circ}C$ were calculated to be 1.02 vol% and 5.03 vol%, respectively. In this study, it was possible to predict the LEL and the UEL by using the lower and upper flash point of tetralin measured by Setasflash closed-cup tester. A new prediction method for the ignition delay time by the ignition temperature has been developed. It is possible to predict the ignition delay time at different ignition temperatures by the proposed model.