• 한국해양공학회지
• /
• 제28권4호
• /
• pp.351-355
• /
• 2014

Today, carbon fibers are used as heating elements. Carbon fibers are generally used to reinforce composite materials because they are lightweight and have a high strength and modulus. Carbon fiber reinforced composite materials are used for aerospace, automobile, and wind turbine blade applications. This work explored the possibility of using carbon fiber reinforced composite materials as self heating materials. The temperatures of the carbon fiber reinforced composites were measured. These results verified that the carbon fiber reinforced composite materials could be used as heating elements. A glass fiber was laminated using various methods. The thermal characteristics of the composites were evaluated. This confirmed that the generation of heat varied according to the lamination thicknesses of the carbon fiber and glass fiber. As the number of carbon fiber laminations increased, the heat-generating temperature increased. In contrast, as the number of glass fiber laminations increased, the amount of heat decreased. The generation of heat and ability to remain warm could be controlled by controlling the carbon fiber and glass fiber laminations.

• 한국유체기계학회 논문집
• /
• 제19권6호
• /
• pp.26-33
• /
• 2016

Combined heat and power (CHP) system is one of the power generation system which can generate both electricity and heat. Generally, mid-size and big-size CHP plant in Korea generate electricity from gas turbine and steam turbine, then supply heat from exhaust gas. Actually, CHP can supply heat using district heater which is located at low pressure turbine exit or inlet. When the district heater locates after low pressure turbine, which called back pressure type turbine, there need neither condenser nor mode change operating control logic. When the district heater locates in front of low pressure turbine or uses low pressure turbine extraction steam flow, which calls condensing type turbine, which kind of turbine requires condenser. In this case, mode change operation methods are used for generating maximum electricity or maximum heat according to demanding the seasonal electricity and heat.

• 대한본초학회지
• /
• 제26권2호
• /
• pp.25-30
• /
• 2011

Objectives : This study was carried out to investigate an antioxidant ability, the change of antioxidant ability, antimicrobial activity and anticancer in functional meat ball and sausage prepared from Lentinus edoes mycelium and texturized soy protein. Methods : This experiments was carried out to investigate antioxidant ability(TBARS, DPPH, SOD-like ability), antibacterial activity and anticancer ability using sarcoma 180 extracts from Lentinus edoes mycelium. Result : Anticancer ability of Lentinus edoes mycelium showed a 28% survival rate and 63% of inhibition rate of tumor, which showed $1.30{\pm}0.4g$ of tumor weight. These results revealed an effective Lentinus edoes mycelium resources as anticancer sources. After heating peoducts prepared from Lentinus edoes mycelium, these products doesn't showed difference between after heating and before heating in measuring of SOD-like activity and DPPH. In DPPH experiment, ethanol extracts showed a high DPPH value as 90.85%, but hot water extracts showed 82.14% in DPPH value. Conclusion : In conclusion, it is very useful resources for preparing functional food on the basis of results from antioxidant(TBARS, DPPH, SOD-like ability), antibacterial activity and anticancer ability using sarcoma 180.

• Macromolecular Research
• /
• 제11권6호
• /
• pp.481-487
• /
• 2003

Polypyrrole (PPy) was coated sequentially by chemical and electrochemical methods on a woven fabric, giving rise to a fabric having high electrical conductivity. We investigated the effects of the preparation conditions on the various properties of the resulting fabric. The PPy-coated fabric with optimum properties was obtained when it was prepared sequentially by chemical polymerization at the elevated temperature of 100$^{\circ}C$ under a pressure of 0.9 kgf/$\textrm{cm}^2$ and then electrochemical polymerization with a 3.06 mA/$\textrm{cm}^2$ current density at 25 $^{\circ}C$ for 2 hrs with the separator plate. The surface resistivity of the resulting fabric was as low as 5 Ω/$\square$ .The PPy-coated fabric prepared under the optimum conditions showed practically applicable heat generating property. When electrical power was supplied to the fabric using a commercial battery for a mobile phone (3.6 V, LGLl-AHM), the temperature of the fabric increased very quickly from room temperature to ca. 55 $^{\circ}C$ within 2 min and was maintained for ca. 80 min at that temperature. The heat generating property of the fabric was extremely stable, exhibiting similar behavior over 10 repeated cycles. Therefore, we suggest that the PPy-coated fabric in this study may be practically useful for many applications, including flexible, portable surface-heating elements for medical or other applications.

• Applied Biological Chemistry
• /
• 제35권6호
• /
• pp.490-494
• /
• 1992

두부의 저장성 향상을 위해 포장한 후 가열처리하여 저장 중 두부의 미생물상과 이화학적인 변화를 검토하였다. 두부는 $CaCl_2$보다 초산으로 응고시키는 것이 저장성 향상에 효과적이었으며, 두부의 저장기간이 경과함에 따라 적정산도, amino태 질소 및 ammonia태질소와 두부현탁액의 탁도는 증가하였다. 두부를 포장하여 가열처리하면 저장초기의 세균수를 효과적으로 줄일 수 있어 저장성을 연장할 수 있었으나 직접가열과 마이크로파 가열간의 차이는 적었다. 초산으로 응고시킨 비가열처리 두부는 $30^{\circ}C$에서 1일만에 세균수가 $6.6{\times}10^6\;CFU/g$에 도달하여 저장성이 감소하며 3분간 가열처리하면 4일간 저장이 가능하였다.

• 설비공학논문집
• /
• 제24권8호
• /
• pp.627-635
• /
• 2012

This study aims at developing an artificial neural network(ANN)-based predictive and adaptive temperature control method to control the openings at internal and external skins, and heating systems used in a building with double skin envelope. Based on the predicted indoor temperature, the control logic determined opening conditions of air inlets and outlets, and the operation of the heating systems. The optimization process of the initial ANN model was conducted to determine the optimal structure and learning methods followed by the performance tests by the comparison with the actual data measured from the existing double skin envelope. The analysis proved the prediction accuracy and the adaptability of the ANN model in terms of Root Mean Square and Mean Square Errors. The analysis results implied that the proposed ANN-based temperature control logic had potentials to be applied for the temperature control in the double skin envelope buildings.

• 한국식품조리과학회지
• /
• 제22권3호통권93호
• /
• pp.402-417
• /
• 2006

Research interest on functional food and phytochemicals has mainly focused on their health effects, mechanism of action and structure-activity relationship for the development of nutraceuticals. Considering the intake of phytochemicals via the normal diet, further information is required on changes in food functionality or individual phytochemicals that occur during the cooking or processing of foods, in order to increase the intake of these bioactive compounds, because many of the unit-operating procedures involved in cooking or food processing may result in physicochemical changes of food constituents. This study reviews the changes of selected phytochemicals, i.e. flavonoids, organosulfur compounds and carotenoids, or food functionality by major cooking or processing procedures such as heating, fermentation, and pH changes. In general, heating has a negative effect on food functionality, although in some cases, mild heating increases bioactive phytochemical contents. Some phytochemicals, including anthocyanins and catechins, are stabilized in lower pH conditions. The structures of phytochemicals, including isoflavones and catechins, are changed by fermentation. The loss of bioactive compounds may be decreased by recently developed cooking or processing methods such as microwave cooking or use of high hydrostatic pressure. However, the effects of cooking and processing procedures on food functionality and phytochemicals are so diverse and dependent on test conditions that further research efforts are needed to form accurate conclusions on the effects of cooking and processing of foods.

• Journal of Electrical Engineering and Technology
• /
• 제10권3호
• /
• pp.1383-1388
• /
• 2015

Proportional integral derivative (PID) control is one of the conventional control strategies. Industrial PID control has many options, tools, and parameters for dealing with the wide spectrum of difficulties and opportunities in manufacturing plants. It has a simple control structure that is easy to understand and relatively easy to tune. Injection mold is warming up to the idea of cycling the tool surface temperature during the molding cycle rather than keeping it constant. This “heating and cooling” process has rapidly gained popularity abroad. However, it has discovered that raising the mold wall temperature above the resin’s glass-transition or crystalline melting temperature during the filling stage is followed by rapid cooling and improved product performance in applications from automotive to packaging to optics. In previous studies, optimization methods were mainly selected on the basis of the subjective experience. Appropriate techniques are necessary to optimize the cooling channels for the injection mold. In this study, a digital signal processor (DSP)-based PID control system is applied to injection molding machines. The main aim of this study is to optimize the control of the proposed structure, including a digital PID control method with a DSP chip in the injection molding machine.

• 한국식품조리과학회지
• /
• 제31권3호
• /
• pp.360-369
• /
• 2015

The objective of this study was to develop remedies to improve sanitary quality of school meals. To analyze the usage of potentially hazardous foods, menus from 180 school foodservice establishments were collected through school websites. Statistical analyses were conducted using the SPSS package program (ver. 20.0). The results of this study are as follows: analysis of the foodservice production process revealed that the following were employed: heating process (70.5%), non-heating process (16.3%), and after-heating process (13.2%). In addition, the cooking methods used for side dishes were: stir-frying (22.1%), saengchae (21.3%), sukchae (15.2%), jorim (12.4%), deep-frying (10.2%), and grilling (9.5%). Overall, 64 menu items known to pose potential microbiological hazards were offered a total of 2,671 times. The usage frequency was high for bibimbap, pork-bulgogi, cucumber-saenchae, seasoned bean sprouts namul, seasoned spinach-namul, and korean cabbage-geotjeori. In conclusion, in order to increase the sanitary quality of school meals, menus or foods that contain microbiological hazards should prepared very carefully with respect to time and temperature management during food production. Also, school foodservice employees must possess proper food safety knowledge and techniques for applying the HACCP system to prevent foodborne illness.

• 설비공학논문집
• /
• 제20권8호
• /
• pp.563-569
• /
• 2008

Radiative, heating is suitable for outdoor heating system in windy and cold seasons. Optimal design of the reflector is very important to maximize heat transfer to a specific target area in the open space. The geometrical optical theory can be applied to analyze efficiency of the reflector. Commercial ray tracing computer programs are available only for limited geometries of the reflector. Alternatively, it may be designed and analyzed through an approximated simple lens theory. Two types of reflectors are analyzed using either of these methods. The key issue in this paper is to propose a new illumination experimental method for determination of the radiative efficiency. Optical light source and illuminometer are employed. The calculated efficiency of the reflector is compared with experimental one for checking the reliability. The relative errors between the experimental and analytical results are less than 5%, which proves the validity of this method. Based on these methodologies, a practical reflector and heating lamp unit is developed.