• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(I)
• /
• pp.208-213
• /
• 2002

Railway wheel and axle are the most critical components in railway system. A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Therefore, more precise evaluation of wheelset strength and safety has been desired. Damages of railway wheel are a spatting by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact and thermal stress from heat induced in braking. The objective of this paper is to estimate the variation and magnitude of the residual stress of railway wheel.

• 신재생에너지
• /
• 제4권2호
• /
• pp.81-86
• /
• 2008

Rotary kiln in cement work has been evaluated for a wide variety of organic wastes such as wood, used tyres, plastic wastes and automobile shredder residue (ASR). However the presence of chlorine hampers the use of ASR as fuel in rotary kiln. Therefore, the behavior characteristics of chlorine components in rotary kiln should be considered to develop an effective method for ASR treatment to recovery energy resources. The aim of this paper is to present the chlorine control system applied to a cement manufacturing process for ASR use as an alternative fuel. In this work, the simulation of bypass unit and cyclones for chlorine control in rotary kiln has been studied and compared with the operation results of field test.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권11호
• /
• pp.1627-1633
• /
• 2012

This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions and combustion properties. Also, in this study, the heavy metals in ash content were analyzed for its possible use as a fertilizer. Proximate analysis of the solid recovered from the swine wastewater after flocculation with organic polymer showed high calorific (5,330.50 kcal/kg) and low moisture (15.38%) content, indicating that the solid separated from swine wastewater can be used as an alternative fuel source. CO and NOx emissions were found to increase with increasing temperature. Combustion efficiency of the solids was found to be stable (95 to 98%) with varied temperatures. Thermogravimetry (TG) and differential thermal analysis (DTA) showed five thermal effects (four exothermic and one endothermic), and these effects were distinguished in three stages, water evaporation, heterogeneous combustion of hydrocarbons and decomposition reaction. Based on the calorific value and combustion stability results, solid separated from swine manure can be used as an alternative source of fuel, however further research is still warranted regarding regulation of CO and NOx emissions. Furthermore, the heavy metal content in ash was below the legal limits required for its usage as fertilizer.

• KSBB Journal
• /
• 제17권4호
• /
• pp.345-349
• /
• 2002

항균성 물질이 함유된 투명한 신기능 포장필름의 제조를 위하여 흡착제로서 수용성 silica를 선택하여 항균성 물질의 흡착 및 내열성을 조사하였다. Methanol 자화 방선균 (MO-16, MO-17)이 생산하는 천연 항균성 물질을 ethylacetate로 추출, 농축하여 silica에 흡착시킨 후 열처리한 결과 15$0^{\circ}C$에서 5분까지 항균효과가 유지되었다. 따라서 투명필름의 제조시에 흡착제로서 silica의 첨가가 효과적이라고 판단되었다. 항균제인 benzoic acid(BA) 는 세균 및 곰팡이에 강한 항균효과를 나타내었으며, 특히 곰팡이에 대한 항균력이 우수하였고, 10$0^{\circ}C$, 5분간 열처리시에도 항균력을 유지하였다. 또한 항균성 물질과 공동 첨가시 약간의 상승효과를 나타내어 필름 제조시 공동 첨가하므로서 첨가량의 감소에 따른 비용의 절감 및 항진균 효과가 보완된 필름제조가 가능하다고 사료되었다.

• 한국전기전자재료학회논문지
• /
• 제20권5호
• /
• pp.399-402
• /
• 2007

The effects of heat treatment on the electrical properties of strained-Si/SiGe-on-insulator (SGOI) devices were examined. We proposed the optimized heat treatment processes for improving the back interfacial electrical properties in SGOI-MOSFET. By applying the additional pre-RTA (rapid thermal annealing) before gate oxidation step and the post-RTA after source/drain dopant activation step, the electrical properties of strained-Si channel on $Si_{1-x}Ge_x$ layer were greatly improved, which resulting the improvement of the driving current, transconductance, and leakage current of SGOI-MOSFET.

• 한국연초학회지
• /
• 제18권2호
• /
• pp.120-125
• /
• 1996

Dried tobacco leaf debris infected with tobacco mosaic virus (TMV) was subjected to heat treatment (6$0^{\circ}C$~10$0^{\circ}C$) with or without addition of moisture and to room temperature for natural decay to examine the periods of time required for the inactivation of PMV in the inoculum source. Wet conditions (60% moisture content of the debris) for heat treatment were more efficient than dry conditions to inactivate the virus at 7$0^{\circ}C$~10$0^{\circ}C$, and which decrease of temperature, the time needed for the viral inactivation increased greatly. At 6$0^{\circ}C$ and 7$0^{\circ}C$, the temperaturein a compost heap during the actively decomposing period, it takes about 15 days or more for the complete inactivation of the virus. However, considering the decrease of the viral infectivity during the decomposition, a shorter period of time will be required to inactivate TMV in the conditions mentioned above, suggesting that a well decomposed organic manure containing tobacco leaf debris may not have infective TMV and may not provide a potential inoculum source.

• 한국재료학회지
• /
• 제23권6호
• /
• pp.339-343
• /
• 2013

Porous Ti-systems with unidirectionally aligned channels were synthesized by freeze-drying and a heat treatment process. $TiH_2$ powder and camphene were used as the source materials of Ti and sublimable vehicles, respectively. Camphene slurries with $TiH_2$ content of 10 and 15 vol% were prepared by milling at $50^{\circ}C$ with a small amount of oligomeric polyester dispersant. Freezing of the slurry was done in a Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$ while unidirectionally controlling the growth direction of the camphene. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was heat-treated at $1100^{\circ}C$ for 1 h in a nitrogen and air atmosphere. XRD analysis revealed that the samples composed of TiN and $TiO_2$ phase were dependent on the heat-treatment atmosphere. The sintered samples showed large pores of about 120 mm which were aligned parallel to the camphene growth direction. The internal wall of the large pores had relatively small pores with a dendritic structure due to the growth of camphene dendrite depending on the degree of nucleation and powder rearrangement in the slurry. These results suggest that a porous body with an appropriate microstructure can be successfully fabricated by freeze-drying and a controlled sintering process of a camphene/$TiH_2$ slurry.

• 생약학회지
• /
• 제20권1호
• /
• pp.25-31
• /
• 1989

In order to establish the standard method for the preparation of processed Aconiti Tuber, Aconiti Tubers were processed under various conditions and the amount and the composition of alkaloids were determined by HPLC. The ratio of sum of benzoylhypaconine and benzoylmesaconine over the sum of acinitine, mesaconitine, benzoylmesaconine and benzoylhypaconine was used as a detoxification index ((BM+BH)${\times}$100/MA+AC+BM+BH). The adequate value of index was obtained from Japanese 'ka-gong bu-ja' which has been used in Japan. The processing procedure was largely devided into two categories. First is heat treating at $120^{\circ}$ and 1. 2 lbs for 60 min. Second is treatment with various kinds of alkaline solutions followed by heat treatment at $120^{\circ}$ and 1. 2 lbs for 60 min. Among the source of processed Aconiti Tubers, dried bu-ja and yom bu-ja, dried bu-ja was more adequate than yom bu-ja because yom bu-ja has the lower value of index than dried bu-ja and lost active components through the desalting periods. Dried bu-ja whish was treated with alkaline solutions followed by heat treatment has the detoxification index, 50% and dried bu-ja which was treated only with hear has 71. 8%. Compared to the value of index of Japanese 'ka-gong bu-ja', 72%, the dried bu-ja treated with heat at $120^{\circ}$ and 1, 2 lbs for 60min was the most adequate. The $LD_{50}$ value of the processed bu-ja was higher than 15 g crude drugs/kg, p.o. in mice.

• 환경위생공학
• /
• 제5권2호
• /
• pp.103-110
• /
• 1990

For production of thermophilic and alkaline protease, Bacillus sp. strain AP-5 was isolated from a compost. The production of the protease was reached at maximum for 4 days at $55^{\circ}$ in standing culture. Chitin and Cellulose as carbon source, and Skim Milk as nitrogen source were favorable for the production of the enzyme. Optimal temperature and optimal pH of the enzyme was $55^{\circ}$ and 11, respectively. Metal ion didn't effect on the enzyme activity, the protease was very stable at heat treatment of 30 min at $55^{\circ}$.

• Journal of Advanced Marine Engineering and Technology
• /
• 제35권5호
• /
• pp.600-607
• /
• 2011

고탄소강은 사용자가 요구하는 특성을 만족시키기 위해 침탄, 질화, 고주파담금질 등에 의해 표면처리 되어져 왔다. 그러나 기존의 처리 방법은 모두 처리물 전체를 가열하거나 균일한 가열을 하지 못하여 표면처리 후 변형의 문제와 처리후의 후가공의 경비문제, 그리고 극히 일부분만 경화가 필요한 부품에는 적용하기 어려운 문제점이 있었다. 이러한 문제를 해결할 수 있는 표면처리법으로로써 레이저열처리 방법이 대두대고 있으며, 레이저열처리는 레이저 빔을 피처리물의 표면에 조사하고 적당한 속도로 이동을 하게 되면 레이저조사부위가 급속하게 가열되고 레이저 빔이 통과한 후에는 표면의 열이 내부로 열전도 되어 급속히 자기냉각(self-quenching)됨으로써 표면에 새로운 기계적 성질을 갖게 하는 열처리법이다. 본 연구에서는 기존의 CW Nd:YAG 레이저 열원보다 효율이 좋은 HPDL을 이용한 고효율, 고기능의 고탄소강 열처리 후 재료적 물성을 평가하였다. 그 결과 레이저빔의 조사속도 및 온도변화에 따른 열처리부 및 모재 부분에 대한 경도특성 및 미세조직의 특성을 명확히 할 수 있었다.