• 척추신경추나의학회지
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• 제7권2호
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• pp.75-81
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• 2012

장요인대 염좌 환자 2명에게 전열침 치료를 시행하여 통증 강도가 증가하였지만 봉독약침 치료를 시행한 후 통증 강도와 요추 가동범위 및 이학적 검진상에서 호전되었음을 보고한다. 이와 같이 봉독약침에 의해 호전 될 수 있는, 염증성 병변을 내재하였거나 진행 될 가능성이 있는 환자에 대한 사전의 감별 진단에 대한 연구 및 전열침 치료의 효과 및 부작용에 대한 체계적인 연구가 추후에 필요할 것으로 사료된다.

• Journal of Biosystems Engineering
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• 제40권3호
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• pp.271-276
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• 2015

Purpose: Quick freezing is widely used in commercial food storage. Well-known freezing techniques such as individual quick freezing require a low-temperature coolant and small cuts for the heat-transfer efficiency. However, the freezing method for bulk food resembles techniques used in the 1970s. In this study, electromagnetic (EM) heating was applied to improve the quick freezing of bulk food. Methods: During freezing, the surface of food can be rapidly cooled by an outside coolant, but the inner parts of the food cool slowly owing to the latent heat from the phase change. EM waves can directly heat the inner parts of food to prevent it from freezing until the outer parts finish their phase change and are cooled rapidly. The center temperature of garlic cloves was probed with optical thermo sensors while liquid nitrogen (LN) was sprayed. Results: When EM heating was applied, the center cooling time of the garlic cloves from freezing until $-10^{\circ}C$ was 48 s, which was approximately half the value of 85 s obtained without EM heating. For the white radish cubes, the center cooling time was also improved, from 288 to 132 s. The samples frozen by LN spray with EM heating had a closer hardness to the unfrozen samples than the samples frozen by LN only. Conclusions: The EM heating during quick freezing functions to maintain the hardness of fresh food by reducing the freezing time from 0 to $-10^{\circ}C$.

• 한국산학기술학회논문지
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• 제17권4호
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• pp.474-479
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• 2016

친환경에너지에 대한 요구가 높아지면서 전기에너지의 사용은 계속 증가하고 있다. 최근 친환경, 에너지 절약을 위해서 유도가열을 이용한 여러 가지 가열방식에 대한 관심이 높아지고 있다. 본 논문에서는 전자유도현상을 이용한 유도가 열방식을 이용하여 보다 친환경적이고 에너지 절약이 가능한 전기온풍기를 설게 제작하였다. 온풍기는 송풍부, 유도가열부 및 전력변환부 등 3부분으로 구성하였다. 유도가열부는 송풍부에 결합되어 송풍부로부터 발생된 바람이 가열되어 분출되며, 전력변환부는 고주파를 인가하여 자속을 발생시킴으로써 유도가열부의 내부를 가열시킨다. 발열방식은 유도가열의 원리를 적용하고, 전력변환효율성을 높이기 위해 공진형 인버터를 사용하였다. 공진형 인버터는 풀브리지 전압형 직렬부하 공진형 인버터를 사용하였다. 유도가열부는 세라믹 계열의 절연체와 SUS40계열의 금속체를 사용했으며, 전력변환부는 정류부, 필터부 및 공진형 인버터부 등으로 구성 하였다. 본 연구에서 제안한 전기온풍기는 기존의 전기히터와 가스히터 등과 비교한 결과, 온도 상승속도가 빠르고, 사용에너지 비용이 절감되는 등 경제성도 있음을 보였다. 개발된 전기온풍기는 가정용, 상업용 및 농업용 등 여러 분야에 친환경 에너지절감형 온풍기로의 적용 가능성이 있다.

• 한국기계가공학회지
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• 제16권6호
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• pp.87-94
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• 2017

Hot stamping processes are possible for tensile strength 1.4 GPa but the strength reduction is appeared from the cooling performance unbalance. And the strength of roll forming process is below than that of hot stamping process owing to using the steel which is lower strength of boron steel. In this study, We provide roll forming process asssisted high-frequency induction heating to solve the problem of conventional one. The experiments were carried out at under various sill side part conditions: high-frequency induction heating conditions of 15, 18, 21, 24, 27 and 30 kW. The high-frequency induction heating temperature was checked with Infrared camera and the sill side parts of mechanical properties and microstructure were measured. The heating temperature of high frequency induction was measured to max $850^{\circ}C$ under the coil power of 30 kW. The tensile strength was 1.5 GPa and hardness was 490 Hv. The martensite structure was discovered under coil power of 30 kW. The weight of steel material sill side having thickness 1.5 mm and the boron steel sill side having thickness 1.2 mm were compared to weight effect. The boron steel sill side reduced 11.5% compared to steel. Consequently, manufacturing process of 1.5 giga-grade's sill side part was successfully realized by the roll forming assisted high-frequency induction heating methods.

• 한국식품영양학회지
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• 제7권4호
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• pp.297-306
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• 1994

This experiment was carried out to investigate the healing loss and the heavy metal residues such as copper, zinc, manganese, cadmium and lead In porcine visceras by inductively coupled argon plasma spectrometer(ICP), and to probe changes when porcine visceras were boiling In water treatment(BWT), heating in autoclave treatment (HAT) and heating In oil treatment (HOT) . The range of heating loss on porcine viscera were BWT(23.11∼34.53%) , HAT(18.48∼28.00%) and HOT(14.20∼25.22%)and the heart tissue were higher and liver were lower than those of the other tissues. The total value of heavy metal residues in large intestine, small intestine, heart, kidney, liver and stomach tissue were 11.298${\pm}$5.302 ppm, 27.825${\pm}$8. 177 ppm, 16.756${\pm}$6.334 ppm 21.107${\pm}$6.057 ppm, 25.369 ${\pm}$ 10.164 ppm and 12.611 ${\pm}$5.513 ppm, respectively. Heavy metal residues in porcine visceras tended to decrease according to heating methods and the variety viscera, and the change of total heavy metal residues on BWT, HAT and HOT were 4.16∼32.57%, 12.01∼28.09% and 9.60∼25.76%, respectively. The decrease of lead element of mean value were 21.76% and copper, zinc, manganese and cadmium element were 18.00∼ 18.16%. The change of heavy metal residues were not significant in the porcine visceras(P>0.05), and the these were significantly correlated among the three heating method(P < 0.05).

• The Journal of Advanced Prosthodontics
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• 제11권4호
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• pp.202-208
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• 2019

PURPOSE. Fabrication of zirconia restorations with ideal mechanical properties in a short period is a great challenge for clinicians. The purpose of the study was to investigate the effect of heating rate on the mechanical and microstructural properties of monolithic zirconia. MATERIALS AND METHODS. Forty monolithic zirconia specimens were prepared from presintered monolithic zirconia blanks. All specimens were then assigned to 4 groups according to heating rate as Control, Group $15^{\circ}C$, Group $20^{\circ}C$, and Group $40^{\circ}C$. All groups were sintered according to heating rates with the sintering temperature of $1500^{\circ}C$, a holding time of 90 minutes and natural cooling. The phase composition was examined by XRD analysis, three-point bending test was conducted to examine the flexural strength, and Weibull analysis was conducted to determine weibull modulus and characteristic strength. Average grain sizes were determined by SEM analysis. One-way ANOVA test was performed at a significance level of 0.05. RESULTS. Only tetragonal phase characteristic peaks were determined on the surface of analyzed specimens. Differences among the average grain sizes of the groups were not statistically significant. The results of the three-point bending test revealed no significant differences among the flexural strength of the groups (P>.05). Weibull modulus of groups was ranging from 3.50 to 4.74. The highest and the lowest characteristic strength values were obtained in Group $20^{\circ}C$ and Control Group, respectively. CONCLUSION. Heating rate has no significant effect on the flexural strength of monolithic zirconia. Monolithic zirconia restorations can be produced in shorter sintering periods without affecting the flexural strength by modifying the heating rate.

• 공업화학
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• 제22권2호
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• pp.214-218
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• 2011

마이크로파 가열 방법과 기존의 가열 방법을 이용하여 석탄회로부터 제올라이트 A를 합성하였다. 반응시간, sodium aluminate의 양, 반응 온도 등이 제올라이트 A의 결정화에 미치는 영향에 대해 연구하였다. $80{\sim}100^{\circ}C$의 범위에서 제올라이트 A의 합성에 필요한 반응 시간은 3~6 h이었으며, 6 h 이상이 되면 결정화도가 오히려 감소하였다. 제올라이트 A의 합성에 필요한 sodium aluminate의 양은 $90^{\circ}C$ 이상에서는 합성용액의 $SiO_2/Al_2O_3$의 비가 0.44~1.05에서 최적이었으며, $80^{\circ}C$에서는 더 많은 양이 필요하였다. 마이크로파 가열 방법은 기존의 가열 방법에 비해 초기 결정화 속도는 약간 증가하였으나, 충분히 결정화되는데 필요한 반응시간은 서로 비슷하였다. 따라서 마이크로파 가열에 의한 석탄회로부터 제올라이트 A의 합성에 미치는 영향은 크지 않다는 것을 알 수 있었다.

• 대한본초학회지
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• 제35권2호
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• pp.1-6
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• 2020

Objectives : Heating process is the traditional processing method that has been applied to reduce the toxicity of dried resin of Toxicodendron vernicifluum (Anacardiacea) used as Geon-chil (乾漆, Lacca Rhois Exsiccata or Toxicodendri Resina). Urushiol, which is found in the plants of Toxicodendron genus, is a toxic compound that is absorbed into the skin and induces allergic dermatitis by being contacted. Hence, the reduction of urushiol level by heating processing of Geon-chil is crucial method for its medicinal application. Methods : Due to lack of Geon-chil processing-related articles, the articles researching the processing of lacquer (漆), as a coating material, were collected and analyzed to investigate the chemical change of urushiol during heating process. Results : The results demonstrate that the resin which was collected from the sap of T. vernicifluum tree was dried under warm and humid conditions repeatedly. During primary drying process, the laccase, a copper-containing enzyme in the resin, participated in the formation of urushiol polymers and thereafter urushiol-related toxicity could be reduced by making a lacquer harder and more stable. Moreover, heating a lacquer over 200℃ could cause thermo-degradation of urushiol polymers, and vaporized thermally degraded urushiol monomers and their by-products, which were determined using pyrolysis/GC-MS. Conclusions : These results support that heating process being performed over 200 ℃, such as stir-frying (炒) or calcination (煅), reduces the urushiol content in Geon-chil and hence, its medicinal use can be more stable without urushiol-related allergic reactions.

• 설비공학논문집
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• 제27권4호
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• pp.179-186
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• 2015

In this study, the actual energy consumption of the secondary side District Heating System (DHS) with different hot water supply temperature control methods is compared. The two methods are Outdoor Temperature Reset Control and Outdoor Temperature Predictive Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side system, the results show that the Outdoor Temperature Predictive Control method saves more energy. In general, the Outdoor Temperature Predictive Control method lowers the supply temperature of hot water, and it reduces standby losses and increases the overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, the Outdoor Temperature predictive Control method saves about 6.6% of energy when compared to the Outdoor Temperature Reset Control method. Also, it is found that at partial load condition, such as during daytime, the fluctuation of hot water supply temperature with Outdoor Temperature Reset Control is more severe than that with Outdoor Temperature Predictive Control. Thus, it proves that Outdoor Temperature Predictive Control is more stable even at partial load conditions.

• 산업공학
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• 제24권4호
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• pp.373-378
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• 2011

High level of accuracy in forecasting heat demand of each district is required for operating and managing the district heating efficiently. Heat demand has a close connection with the demands of the previous days and the temperature, general demand forecasting methods may be used forecast. However, there are some exceptional situations to apply general methods such as the exceptional low demand in weekends or vacation period. We introduce a new method to forecast the heat demand to overcome these situations, using the linearities between the demand and some other factors. Our method uses the temperature and the past 7 days' demands as the factors which determine the future demand. The model consists of daily and hourly models which are multiple linear regression models. Appling these two models to historical data, we confirmed that our method can forecast the heat demand correctly with reasonable errors.