• Title/Summary/Keyword: various heating methods

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Thermal Characteristics of Polypropylene in Combustion Reaction Using TGA (TGA를 이용한 폴리프로필렌의 연소반응에서의 열적 특성 연구)

  • Kang, Yun-Jin;Seo, Su-Eun;Seo, Gyu-Suk;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.10 no.4
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    • pp.111-120
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    • 2008
  • The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

A Study of Winterization Design for Helideck Using the Heating Cable on Ships and Offshore Platforms (열선을 이용한 해양플랜트 헬리데크의 방한설계에 관한 연구)

  • Bae, So Young;Kang, Gyu-Hong
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.1
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    • pp.43-48
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    • 2017
  • In recent years, the demand for ships and offshore platforms that can navigate and operate through the Arctic Ocean has been rapidly increasing due to global warming and large reservoirs of oil and natural gas in the area. Winterization design is one of the key issues to consider in the robust structural safety design and building of ships that operate in the Arctic and Sub-Arctic regions. However, international regulations for winterization design in Arctic condition regulated that only those ships and offshore platforms with a Polar Class designation and/or an alternative standard. In order to cope with the rising demand for operating in the Arctic region, existing and new Arctic vessels with a Polar Class designation are lacking to cover for adequate winterization design with HSE philosophy. Existing ships and offshore platform was not designed based on reliable data based on numerical and experiment studies. There are only designed as a performance and functional purposes. It is very important to obtain of reliable data and provide of design guidance of the anti-icing structures by taking the effects of low temperature into consideration. Therefore, the main objective of this paper reconsiders anti-icing design of aluminum helideck using the heating cable. To evaluate of reliable data and recommend of anti-icing design method, various types of analysis and methods can be applied in general. In the present study, finite element method carried out the thermal analysis with cold chamber testing for performance and capacity of heating cables.

Effect of Heating Conditions on the Resistant Starch Formation (가열방법에 따른 효소저항전분 생성)

  • Lee, Shin-Kyung;Mun, Sae-Hun;Shin, Mal-Shick
    • Applied Biological Chemistry
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    • v.40 no.3
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    • pp.220-224
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    • 1997
  • As corn starches with different amylose content were heated at different temperature $(100^{\circ}C,\;121^{\circ}C)$ with starch / water ratio (1:3.5, 1:9) and heating-cooling treatment was repeated up to 4 times, the yield of RS(resistant starch) from heated corn starches was investigated by the enzymatic-gravimetric method and the ${\alpha}-amylase$ treatment. Compared to ${\alpha}-amylase$ method, enzymatic-gravimetric method was more effective to hydrolyze the amorphous region of heated corn starch. With increasing the amylose content and the number of heating-cooling treatment, the yield of RS increased, regardless of isolation method. Heated corn starches formed at $121^{\circ}C$ provided higher yield of RS than those formed at $100^{\circ}C$. Higher RS yield was also observed in the case of starch/water ratio (1:3.5) compared to the case of ratio (1:9).

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Cost Allocation of Heat and Electricity on a Steam-Turbine Cogeneration (증기터빈 열병합발전에서 열과 전기의 비용배분)

  • Kim, Deok-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.9
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    • pp.624-630
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    • 2008
  • When various kinds of outputs are produced from a single energy system, the methodology which allocates the common cost to each output cost is very important because it is directly related with the profit and loss of producers and purchasers. In the cost allocation methodology of the heat and the electricity on a cogeneration, there are energy method, work method, proportional method, benefit distribution method, exergetic methods, and so on. On the other hand, we have proposed a worth method which can be applied to any system. The definition of this methodology is that the unit cost of a product is proportion to the worth. Where, worth is a certain evaluating basis that can equalize the worth of products. In this study, we applied worth method to a steam-turbine cogeneration which produces 22.2 MW of electricity and 44.4 Gcal/h of heat, and then we allocated 2,578 $/h of common cost to electricity cost and heat cost. Also, we compared with various cost allocation methods. As the result, we conclude that exergy of various kinds of worth basis evaluates the worth of heat and electricity most reasonably on this system.

The Experimental Study of Various Salts on the Characteristics of Heat Transfer in Indirect Moxibustion with Salt (염(鹽)의 종류(種類)에 따른 격염구(隔鹽灸)의 열전달(熱傳達) 특성(特性)에 관한 실험적(實驗的) 연구(硏究))

  • Lee, Geon-mok;Lee, Gun-hyee;Seo, Eun-mi
    • Journal of Acupuncture Research
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    • v.21 no.1
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    • pp.119-135
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    • 2004
  • Objective: The purpose of this study is to investigate the mechanism and effect of moxibustion with salt objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxibustion with salt. Methods: We have selected of the moxibustion with salt of indirect moxibustion. We make a comparative study of the thermodynamic characteristics of moxibustion with salt as a kind of the 4 salt. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa. Results: 1. We make out that it is not significantly change the time of thermal conduction of moxibustion with salt as a kind of 4 salt. 2. The heating period of Refined Salt was long and that of Sun-dried Salt was a short time respectively. The heating period of maximum tamperature is high Sun-dried Salt, Mechanical Salt and Refined Salt orderly. Maximun heating speed in the heating period was $0.151{\sim}0.184^{\circ}C/sec$ and at the same tendency of the maximum temperature in the heating period. 3. The retaining period was shorter than the heating period respectively, that is 15~24% of the combustion time of in the heating period. We make out that it is not significantly different the time of the retaining period as a kind of 4 salt. The mean temperature of retaining period was $43.2{\sim}48.1^{\circ}C$, that was extraordinarily high temperature. 4. We make out that it is not significantly different the time of the cooling period as a kind of 4 salt. The cooling period was measured 223~233sec. Beacuse the same density and size of moxa combustion was made an experiment. 5. The effective combustion time of Refined Salt is longer(259sec) than that of Sun-dried Salt(173sec). It is significantly different the time of the combustion time as a kind of 4 salt. 6. It is significantly different the Sample deviation of the combustion time as a kind of 4 salt because of the water content of the 4 salt individually. Conclusions: As the base on this study, we obtained the conclusion as the follows. The salt of moxibustion with salt was fitted for Sun-dried Salt due to making to Mechanical Salt recently. The Refined Salt is composition rate to another and small size comparatively. So It was fitted for the salt of moxibustion with salt. It is necessary to study continuously about the more suitable moxibustion with salt and quantitative analysis about the moxibustion with salt.

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Studies on the Characteristics of Rubber Vulcanization Exotherm by Differential Scanning Calorimetry. (Differential Scanning Calorimetry에 의(依)한 고무의 가황발열특성(加黃發熱特性)에 관(關)한 연구(硏究))

  • Choi, Sei-Young;Paik, Nam-Chul
    • Elastomers and Composites
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    • v.19 no.1
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    • pp.13-31
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    • 1984
  • The purposes of this dissertation are to demonstrate that DSC theromoanaytical methods of vulcanization can provide useful informations on the vulcanization characteristics of industrial formulations and also provides the potential basis for a rapid and complete method of sulfur and vulcanizing accelerator analysis for quality control. The influences of those factors such as heating rate, scan temperature, vucanizing accelerator's type and concentration upon vulcanization exotherm in NR and NBR compounds in the presence of vulcanizing accelerators such as TMTD,MBTS,DPG,TMTM,CBS, and MBT were evaluated by means of DSC. In order to examine the credibility in the DSC method, the same samples which were used for DSC method were studied to compare the DSC results with the ODR (Oscillating Disk Rheometer) data. The results obtained were as follows 1. In the DSC dynamic experiments, the observed enthalpy results from vulcanization depends upon the heating rate; In the range of 2 to $20^{\circ}C/min$ of heating rate, as the heating rate was increased the enthalpy change was also increased. However, over the heating rate of $30^{\circ}C/min$ it was observed that the enthalpy change was decreased as the heating rate was further increased. Without regard to the change of enthalpy, tremendous instantaneous heat evolving was observed in the range of high heating rates. 2. For the samples which are added with various vulcanizing accelerators, the activation energies of vulcanization were as follows; 3. Regarding to the influences of vulcanizining accelerator's types upon the characteristics of vulcanization exotherm, NR and NBR compounds in the presence of thiuramsulphide compounds type accelerators such as TMTD, TMTM, were exhibited sharper and higher vulclanization exotherm than others. From the resuts of DSC thermograms which was distributed in even shape in the broad temperature range, it was clearly shown that the guanidine compounds type accelerator such as DPG acts as a delayed acting accelerator. 4. In the comparison of DSC and ODR results, the dependency of temperature in the cure rate and the observed conversions show good agreements between two results. 5. In the same curatives, by the comparison of glass transition temperatures, it was possible to predict relative values of maximum torques. Consequently, from the present studies, it is shown that the DSC thermoanalytical method can provide an alternate new method for rapid and complete quality control analysis of rubber industry.

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Development of a Method for Producing Liposome Ascorbic acid with Increased Bio-absorption (생체 흡수율이 증가된 liposomal ascorbic acid 제조법 개발)

  • Cha, Ji Hyun;Woo, Young Min;Jo, Eun Sol;Cha, Jae Young;Lee, Sang Hyeon;Lee, Keun Woo;Kim, Andre
    • Journal of Life Science
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    • v.32 no.3
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    • pp.232-240
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    • 2022
  • Various methods are known for preparing liposomes, the simplest being the Bangham method which has been widely used. Although it is possible to produce liposomes effectively on a small experimental level with this approach, large-scale production cannot be easily performed due to difficulties in removing the organic solvent and the size of the reactor required to form the lipid film. On the other hand, emulsion can mass produce tons of liposomes with uniform particles but has the disadvantage of a significantly low capture rate. This study therefore developed an optimal liposome processing method using heat with improved capture rate and stability, and bio-absorption experiments were performed by oral administration to SD rat alongside capture rate, particle size, and zeta potential. Through the heating method, a small and uniform liposome of about 214 nm was formed and the capture rate was 38.67%, confirming that the liposome prepared by heating has a higher capture rate than the 26.46% achieved through emulsion. Comparing blood concentrations, it showed a 1.5 to 2 fold increase in all groups, gradually decreasing until 4-12 hr. The highest blood concentration of ascorbic acid powder was about 12.017 ㎍/ml, the emulsion liposome 13.871 ㎍/ml, and the heating liposome 16.322 ㎍/ml, thereby showing an improved absorption rate.

Constructing Neural Networks Using Genetic Algorithm and Learning Neural Networks Using Various Learning Algorithms (유전알고리즘을 이용한 신경망의 구성 및 다양한 학습 알고리즘을 이용한 신경망의 학습)

  • 양영순;한상민
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.216-225
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    • 1998
  • Although artificial neural network based on backpropagation algorithm is an excellent system simulator, it has still unsolved problems of its structure-decision and learning method. That is, we cannot find a general approach to decide the structure of the neural network and cannot train it satisfactorily because of the local optimum point which it frequently falls into. In addition, although there are many successful applications using backpropagation learning algorithm, there are few efforts to improve the learning algorithm itself. In this study, we suggest a general way to construct the hidden layer of the neural network using binary genetic algorithm and also propose the various learning methods by which the global minimum value of the teaming error can be obtained. A XOR problem and line heating problems are investigated as examples.

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Analytical Study on the Cooking in Zu Bang Moon ("주방문(酒方文)"의 조리(調理)에 관(關)한 분석적(分析的) 연구(硏究))

  • Kim, Gwi-Young;Lee, Sung-Woo
    • Journal of the Korean Society of Food Culture
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    • v.1 no.4
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    • pp.335-349
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    • 1986
  • 'Zu Bang Moon', a book of cooking, was written in Korean in the 17th century by Mr. Hwa. Various cooking methods of traditional foods were described in this book. The kinds of cookingfoods were Wine 28, Guksu (noodle) 3, Side dish 23, Seasoning 10, and Dessert 10. The materials used in the cooking foods were cereals, vegetables, fishes, meats, etc. 9 kind of Seasonings used in cooking foods such as salt, and herbs such as black pepper. The cooking methods were different and complicated. The way of heating were also different such as to stew, to boil, to steam, to pan-boil, to frying, etc. Utensils and table wares used for processing and cooking were poor and specific. The measuring units were not accurate and unscientific. Many of special words and expressions which are not used today in cooking and processing were, reviewed.

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Analytical Study on the Cooking in "Bok Sik Bang" (복식방의 조리에 관한 분석적 연구)

  • 이혜정;이성우
    • The Korean Journal of Food And Nutrition
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    • v.3 no.2
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    • pp.185-200
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    • 1990
  • "Bok Sik Bang', a book of cooking, was written in Korea in the 17 th century Various Cooking methods Of traditional foods were described in this book. 1. The kinds of cooking foods were Wine(59), Side dish(39), Seasoning(12), and Dessert(5) 2. The materials used in the cooking foods were cereals, vegetables, fishes, meats and etc. 3. The cooking methods were different and complicated. 4. The way of heating were also different such as to stew, to boil, to pan-boil, to frying, etc. 5. Utensils and table wares used for processing and cooking were poor and specific. 6. The measuring units were not accurate and unscientific. 7. Many of special words and expressions which are not used today in cooking and processing were reviewed.ewed.

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