• 한국표면공학회지
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• 제34권3호
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• pp.240-246
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• 2001

The possibility of using a glass block with the composition of sodium borosilicate as starting materials for GRIN glass was examined from the view points of the phase separation of the matrix glass, the effects of leaching and the heating conditions for a porous structure, and the change in the refractive index. Glass specimens with similar compositions were prepared in the form of porous glass using a phase-separation technique. An examination of the heating and leaching conditions and the microstructure dependence of these conditions was made.; Specimens with porous structure were obtained when the heat treatment and leaching conditions were fixed at $540^{\circ}C$ for 30hrs and in a 0.3N$ H_2$$SO_4$ solution at $100^{\circ}C$, respectively. The resultant specimens had some important features on the GRIN glass.; the depth of the gradient and the change in refractive index (Δn) were 4mm and 0.015~0.02, respectively.

• 대한한의학회지
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• 제41권3호
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• pp.81-97
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• 2020

Objectives: The objective of this study is to review the methods of combining acupoints of HANGYEOK(Cooling Mode) and YEOLGYEOK(Heating Mode) in Saam Acupuncture Method. Methods: We searched and investigated the journals and literatures by OASIS(Korea Institute of Oriental Medicine) and relevant searching engines with the key word "Saam, Hangyeok, Yeolgyeok". Unfortunately there was no relevant articles on this theme except six literatures. Six literatures with the key words relevant to Saam and acupuncture were selected and analyzed according to each composition of acupuncture prescription especially focusing on HANGYEOK and YEOLGYEOK. Results: Analyzing HANGYEOK and YEOLGYEOK of 12 meridians, two different methods emerged. In HANGYEOK to treat Heat Pattern, one method is to tonify Water points and directly sedate Fire points. The other is also to tonify Water point, but sedate Earth points instead of Fire points. It is assumed that Earth sedation method is to eradicate the underlying Fire. In only Heart meridian and Pericardium meridian there is one method to treat Heat Pattern: Water tonification and Fire Sedation. In YEOLGYEOK to treat Cold Pattern, there is one method to tonify Fire points and sedate Water points. In Pericardium meridian and Triple Energizer meridian there are some different combination of acupoints depending on literatures. Conclusions: Considering HANGYEOK and YEOLGYEOK in Saam Acupuncture Method, two methods are mainly discussed in HANGYEOK; Water Tonification Fire Sedation and Water Tonification Earth Sedation. To remove the underlying Fire, it is regarded that Water Tonification Earth Sedation is appropriate and close to Saam's thought.

• 한국화재소방학회논문지
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• 제7권2호
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• pp.24-28
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• 1993

The flash point for flammable liquids (alcohol, aromatic compounds) were measured by Penskt-Martens's measuring apparatus with closed cup. As a result, it was observed that the flash points had the regular tendency according to the carbon number and the molecular structure. Consequently, the flash point for the alcohols were increased in proportion to the increase of the carbon number and branch number. The differences between the literature and experimental data are 14.6% for the relative error and 3.46$^{\circ}C$ in average for the measuring temperature.

• 항공우주기술
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• 제3권1호
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• pp.155-169
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• 2004

발사체나 재돌입 비행체는 대기 중을 높은 Mach 수로 비행함으로써 그 표면이 공력가열 현상에 의한 초고온 환경에 노출되게 된다. 이러한 공력가열로부터 발사체 자체나 탑재체를 보호하기 위해서는 물체 표면에 가해지는 열적 부하(Thermal Load)를 정확히 예측하고 필요한 곳에는 적절한 단열 처리를 해 주어야만 한다. 그러나 탑재체의 중량을 최대한 늘리기 위해서는 지나친 단열재의 추가를 막을 수 있도록 엄밀한 열 해석 및 시험이 수행 되어야 할 것이며, 최종적으로 공력가열 시험에 의해서 필요한 단열재의 양이 결정된다. 본 연구에서는 KSR(Korea Sounding Rocket) 시리즈의 개발을 위해 사용되어 왔던 공력가열 시험설비(ATSF, Aerodynamic Thermal Simulation Facility)를 KSLV 시리즈의 개발에 적합하도록 사양 향상(Upgrade) 시키기 위한 설계를 위해 고려해야할 사항이 무엇인지 살펴보았다. 먼저 설비의 필요성 및 그 한계에 대하여 고찰하였으며, KSLV 개발을 위해서는 어떤 기능을 갖추어야 할지를 고려하였다. 마지막으로 필요한 장비의 사양을 대략적으로 제안하였으며, 이는 앞으로 수행될 상세 설계 및 제작/설치의 밑바탕이 될 것이다.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1936-1943
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• 2015

The present study developed an efficient and environmentally friendly method for recovering polyhydroxybutyrate (PHB) from Cupriavidus necator. Several non-halogenated solvents were tested and it was found that butyl acetate and ethyl acetate are powerful solvents for the biopolymer. Testing was performed to examine the effects of temperature (25℃ until temperature below solvent boiling points) and heating incubation time (0-60 min) on the two solvents. Butyl acetate had a higher recovery level (96%) and product purity (up to 99%) than ethyl acetate at 103℃ and a heating incubation time of 30 min. Under these conditions, PHB recorded the highest molecular weight of 1.4 × 10⁶ compared with the standard procedure (i.e., recovery using chloroform). The proposed strategy showed that butyl acetate is a good alternative to halogenated solvents such as chloroform for recovery of PHB.

• Journal of Nutrition and Health
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• 제37권8호
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• pp.722-731
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• 2004

The objective of this study was to evaluate the microbiological quality of non-heat-processed foods for implementation of a HACCP (Hazard Analysis and Critical Control Point) system in day-care center foodservice operations. The evaluating points were microbial assessment of foods, utensils, and employee's hands during preparation, cooking, and serving. The temperature of non-heated food being served was also measured. Microbiological quality was assessed using 3 M Petrifilm/syp TM/ to measure total plate count and coliforms for food and utensils and Staphylococcus aureus for hands in five Gumi day-care centers. Results showed low microbiological quality of non-heated foods. This was probably due to contaminated raw ingredients and cross-contamination that occurred during preparation and cooking (e.g., unsatisfactory washing and disinfection of raw materials and utensils). These results suggest that it is essential to educate employees on good personal hygiene (hand washing) , prevention of cross-contamination through use of properly washed and sanitized utensils, and proper washing and disinfection of raw vegetables. Establishing Sanitation Standard Operating Procedures (SSOPs) are an essential part of any RACCP system in day-care center foodservice operations.

• 한국세라믹학회지
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• 제43권8호
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• pp.486-491
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• 2006

A new $TiN-Ti_5Si_3$ bulk composite was synthesized from preceramic, inorganic polymer (methylpolysilsesquioxane) and $TiH_2$ filler powders via polymer pyrolysis. Using this process, ceramics with high melting points can be produced relatively easily to a near net shape. The $TiN-Ti_5Si_3$ composite oxidized slowly during heating to $1000^{\circ}C$. During heating at the temperatures of at 700 and $800^{\circ}C$, TiN oxidized to Rutile-$TiO_2$ whereas $Ti_5Si_3$ resisted to oxidation. The oxide scale formed consisted primarily of $TiO_2$ containing $Ti_5Si_3$.

• Design & Manufacturing
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• 제11권2호
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• pp.15-19
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• 2017

Carbon fiber reinforced plastic (CFRP) is applied as structural material. CFRP is excellent in plane strength / stiffness and don't haves rust. Lightweight, rigid and robust at the same time as transportation material. Aluminum alloy and reinforcement material The application is increasing rapidly. In this study, the prototype of a semi - Monocoque structure frame, Longeron, Stringer, Skin of the aircraft, restraining the rigidity Clips of the aircraft was designated as the target product and the experiment was conducted. ln the experiment, (1) For CFRTP 3 points, data on heating, transfer, and cooling were measured using Thermo Couple, and optimum temperature required for flexible state was obtained. Heating was performed at a temperature 15% higher than the provided temperature. (2) By using a pneumatic press during molding, by dividing LH, center and RH according to the cooling time, thickness parameter of the target product due to the load is measured, and thickness control and time-deviations were analyzed and cross sections were observed with a low magnification microscope.

• 한국의류학회지
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• 제16권3호
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• pp.285-298
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• 1992

In this study, bedclimate was investigated depending on various bedquilts used oin ondol in summer. The environmental room condition was maintained at 26: $1^{\circ}C,\;75{\pm}3\%$ R.H., while the ondol surface was kept at $25{\pm}1^{\circ}C$ without heating. The types of bedquilts were hemp, cotton, quilt made of polyester padding with polyester/cotton cover. Two healthy young women were subjected for seven hours' sleep with two replications for this study. The results are as follows. 1) The range of the temperature under the mattress ($25.2\~32.4^{\circ}C$) was lower than that of the temperature on the mattress ($28.8\~35.5^{\circ}C$), or that of the temperature inside the bedquilts ($30.3\~34.4^{\circ}C$). The humidity inside the bedquilts increased during sleeping, and the range of R.H. was $58\~80\%$. 2) The ranges of bedclimate which subjects feel comfortable were $30.5\~33.8^{\circ}C$ on the mattress, $31.0\~34.9^{\circ}C$, $61\~74\%$ R.H. inside the bedquilts. At this range, the mean skin temper-ature of the subjects was $34.3^{\circ}C\~35.2^{\circ}C$. 3) When there was no heating, the weight of the bedding increased during sleeping, and the weight increase was largest in the case of mattress. 4) There were correlations among the skin temperature of three points of the body (abdomen, thigh, foot) and the temperature and R.H. inside the bedquilt. 5) The effect of the type of bedquilts on the microclimate and physiolosical responses were significant. 6) Generally, when there was no heating, the body heat was transferred to the ondol floor, in summer, heat was transferred mostly through the mattress.

• 한국의류학회지
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• 제14권1호
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• pp.44-54
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• 1990

The purpose of this study was to investigate the effects of thickness of the sleeping pad on the physiological responses and the microclimate in the heating ondol room during sleeping time. The measuring points were skin temp., weight loss and body movement as physiological responses and the compression ratio, the temp. on/under the sleeping pad, the inside limp. of the sleeping quilts and subjective sence while 7 hours sleeping. Thickness of sleeping pads was 27.2 mm(A), 34.8 mm (B), 47.9 mm(C) used for 90 days and no used pad 60.7 mm(D). The floor surface temp. was keeping $29{\pm}1^{\circ}C$ while the environmental conditions was at $23{\pm}1^{\circ}C$ ($50{\pm}5\%$ R.H.) The results were as followings; 1) The mean compression ratio after using the sleeping pads for 45 days was about $70\%$ , and it wasn't increased any more thereafter 2) After 2 hours sleeping the temp. under the sleeping pads was shown that C and D were higher than A and B, and the temp. on the sleeping pads was shown that A and C pads were higher than B and D. But after 3-4 hours sleeping the skin temp. of legs was shown that B and D pads were higher than A and C. 3) Weight loss for C pad was significantly higher than others. Body movement and side position in tying was higher in A and C pads than B and D. 4) The inside temp. of quilt for A and C pads were higher in the early part of sleeping period than those of B and C pads and relative humidity was lower in C than others. 5) D pad was softer than others and fatigue degree was turned out to be lowest in D, the highest in A. From this point of view, we concluded that thickness of the sleeping Pad in the heating ondol room had different characteristic from that in no heating ondol room. And 35 mm used pad was turned out to be proper.