• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.57-59
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• 2015

A method to measure heating value of natural gas using sound velocity and thermal conductivity is proposed to solve the low heating value issues of imported natural gas in South Korea. Natural gas generally consists of methane, butane, ethane, and inert gases. Heating value changes as the gas material properties, such as density, wobbe index, etc., varies. It is highly important to measure heating values of natural gases accurately because measuring the heating value depends on the given natural gases' components. Therefore, sound velocity and thermal conductivity is measured to estimate indirectly heating value of Natural gas with their changed components.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1387-1390
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• 2008

This study evaluated the effects of heat treatment on antioxidant activity of Rehmannia radix Libosch (RRL). RRL was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid content, and antioxidant activity were investigated. With increased heating temperature and exposure time, total content of polyphenol, flavonoid, as well as antioxidant activity increased. The highest total polyphenol and flavonoid contents were 21.65 and 3.56 mg/g, respectively, these values were occurred after heating for 3 hr at $150^{\circ}C$ (RRL was 5.09 and 0.83 mg/g, respectively). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was highest value of 83.46% after heating for 3hr at $150^{\circ}C$. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity was highest value of 20.43mg ascorbic acid (AA) eq/g after heating for 2 hr at $150^{\circ}C$. There were highly significant differences in the total polyphenol, flavonoid content, and antioxidant activity among heating temperatures and times (p<0.001), with heating temperature having the greater effect.

• 한국세라믹학회지
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• 제48권1호
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• pp.14-19
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• 2011

Microwave heating (MW) was studied for the sintering of amorphous powders. In comparison to conventional heating (CV), the results show that microwave heating has the potential to substantially accelerate the sintering process and allow for highly densified solidification by eliminating the pores and increasing the shrinkage rate. In the heat treatment to synthesize aluminum borate ($Al_{18}B_4O_{33}$) whiskers from precursors, it was found that microwave heating helps the formation of $Al_{18}B_4O_{33}$ crystal as well as the decrease of crystallization temperature of $Al_{18}B_4O_{33}$ to a level significantly lower than the previously reported value of $1050^{\circ}C$.

• Food Science and Biotechnology
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• 제16권5호
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• pp.828-831
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• 2007

We evaluated the effects of heat treatment on various properties of onion extracts (Allium cepa). Onion was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid, and free sugar contents, and antioxidant activity were investigated. With increased heating temperatures and exposure times, the total contents of polyphenols and flavonoids, as well as antioxidant activity increased. The highest total polyphenol content (189.80 mg/100g) occurred after heating for 2 hr at $140^{\circ}C$. The highest total flavonoid content (252.51 mg/100g) occurred after heating for 3 hr at $150^{\circ}C$. The antioxidant activity assessed using the DPPH method was highest, at 2.1 mg/mL ($IC_{50}$ value), after heating for 2 hr at $150^{\circ}C$. Correlations between antioxidant activity and the total polyphenol, total flavonoid, and fructose contents were highly significant (all p<0.01). The optimal heating time and temperature were 2 hr and $130^{\circ}C$.

• 한국환경보건학회지
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• 제26권4호
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• pp.38-44
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• 2000

Compared to other waste, waste tire has much discharge quantity and calorie. When we use waste heat from waste tire, it can be definitely better substitute energy than coal and anthracite in high oil price age. To use as a basic data for providing low cost and highly effective heating system, following conclusion was founded. Annual waste tire production was 19,596 million in 1999, Recycling ratio was almost 55% and more than 8.78 million was stored. Waste tire has lower than 1.5% sulfur contain ratio which is resource of an pollution, So it is a waste fuel which can be combustion based on current exhaust standard value without any extra SOx exclusion materials. Waste tire has 9,256Kcal/kg calorific value and it is higher than waste rubber, waste rubber, waste energy as same as B-C oil. When primary and second air quantity was 1.6, 8.0 Nm$^3$/min, dry gas production time was 270min and total combustion time was 360 min. In the SOx, NOx, HC of air pollution material density were lower than exhaust standard value at the back of cyclone and dusty than exhaust standard value without dust collector.

• 유기물자원화
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• 제23권3호
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• pp.51-59
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• 2015

가축분뇨 슬러지는 유기물의 농도가 높고 일부 중금속이 높은 농도로 혼합되어 있어 해양에 배출될 경우 환경에 부정적인 영향을 끼칠 수 있다. 본 연구에서는 가축분뇨 슬러지 처리에 열가수분해 기술을 적용하여 연료화 가능성을 판단하고 최적 운전조건을 도출하고자 하였다. 밀폐형 고압반응기를 사용하여 가축분뇨 슬러지를 $170{\sim}210^{\circ}C$까지 온도변화를 주면서 열가수분해 하였고, 반응 후 생성된 액상생성물과 탈수케이크의 분석을 실시하였다. 반응온도 $190^{\circ}C$로 운전하는 것이 가장 효과적인 것으로 나타났으며, 반응온도 $190^{\circ}C$일 때 고체생성물의 고위발열량은 5,050 kcal/kg, 저위발열량은 4,740 kcal/kg으로 연료로서 충분히 가치가 있는 것으로 판단되었다.

• 한국조리학회지
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• 제24권3호
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• pp.113-120
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• 2018

In this study, to enhance the applicability of the black current as a natural pigment and functional material, a jelly was produced by adding 0 %, 3 %, 6 %, 9 %, and 12 % of the black current powder. The pH and moisture content of the black currant jelly decreased with the addition of the black currant powder, while the sweetness($^{\circ}brix%$) of the jelly increased with the addition of the black currant powder. The chromaticity of the jelly was reduced as the black current powder was added, as the L value and b value increased. Texture measurement score in terms of hardness, chewiness and brittleness of groups with 3% and 6% black currant powder were significantly higher when compared to the control group. The contents of total polyphenol, DPPH radical scavenging activity, and NSA radical scavenging activity of groups by the addition of black currant powder were higher than those of control group. The anthocyanin contents increased proportionally with increasing levels of black currant powder. The sensory evaluation scores in terms of after swallowing, appearance, odor, taste, texture, and overall preference of groups with 6% and 9% black currant powder. Also, the anti oxidative activity and anthocyanine pigment in black current powder are highly visible even after the heating process, so it may be helpful to enhance the functionality of jelly by using natural colors that are highly antioxidants in jelly manufacture.

• 농업과학연구
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• 제6권2호
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• pp.198-204
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• 1979

개암종실(種實)의 가공적성(加工適性)을 검토하기 위한 기초연구(基礎硏究)로서 종실(種實)의 일반성분(一般成分), 종실유(種實油)의 이화학적(理化學的) 성질(性質), 지방산(脂肪酸) 조성(組成) 및 열안정성(熱安定性)과 종실박(種實粕)의 amino acid 조성(組成)을 조사(調査)한 결과는 다음과 같다. 1. 종실(種實)의 유지함량(油脂含量)은 59.6%이었고 단백질(蛋白質)은 17.3%로서 높은 영양가(營養價)가 인정(認定)되었다. 2. 종실(種實)의 이화학적(理化學的) 성질(性質)은 굴절율(屈折率) : 1,469, 비중(比重) : 0.912, 감화가 : 167.3, 천소가(天素價) : 93.43으로서 불건성유(不乾性油)에 속(屬)하였다. 3. 종실유(種實油)의 이화학적(理化學的) 성질(性質) oleic acid 가 다량함유(多量含有)되어 있었으며 olive oil 과 비슷하였다. 4. 종실박(種實粕)의 단백질(蛋白質)은 18종(種)의 amino acid 로 구성(構成)되었으며 특히 glutamic acid 의 함량(含量)이 높았다. 5. 과산화물가(過酸化物價)는 $150^{\circ}C$ 처리구(處理區)에서 30시간(時間), $180^{\circ}C$ 처리구(處理區)에서 10시간(時間)에 최고가(最高價)에 달(達)하였다가 감소하였으며 carbonyl 가(價)는 가열(加熱)함에 따라 계속 증가하였다. 6. 산가(酸價)는 $150^{\circ}C$ 처리구(處理區)의 30시간(時間)과 $180^{\circ}C$ 처리구(處理區)의 10시간(時間)의 결과(結果)와 비슷하였다.

• 한국식품조리과학회지
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• 제27권1호
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• pp.75-84
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• 2011

The aim of this study was to develop a convenient brown sauce product with long shelf life that has similar taste and quality characteristics with sauce used in restaurants. Response surface analysis was carried out to optimize brown sauce. Extracted brown sauce powder was subjected to hot air drying, infrared drying, freeze drying, and spray drying to determine the appropriate drying method for brown sauce manufacturing. The optimum extraction conditions were set by superimposing and reading each reaction surface that satisfied all of the sensory characteristics such as color, smell, taste, concentration, and overall preference level in order to set the optimum conditions for brown sauce production. The optimum extraction conditions for brown sauce were determined to be heating time 30 min, gelatin addition quantity 9.00%, and tomato paste addition quantity 11.25%. Reliability test showed a similar value to the predicted scope when compared to the experimental value obtained under the same conditions as the predicted value according to RSM (response surface methodology), enabling verification of the derived regression formula. Product powder of ideal brown sauce by heating, infrared radiation, freezing, and spray drying and investigate result for functional tests of color, flavor, taste, viscosity, overall acceptability and show highly acceptability on powder by infrared rays and freeze-drying methods. Especially, infrared radiation method resulted in favorable color and flavor values while freeze-drying method produced good taste and viscosity values and high overall acceptability. Therefore, infrared radiation drying method and freeze-drying method to product powder.

• 한국지열·수열에너지학회논문집
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• 제18권4호
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• pp.22-32
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• 2022

To reduce energy consumption and CO₂ emission in building sector, a ground source heat pump system has been highly adopted due to its high efficient by many regulation. A certification system has been operated to distribute reliable and high-efficient heat pump units. In this study, the performance status of the recently certified ground source heat pump unit with components was investigated. All heat pump units certified from 2015 to 2020 were water to water heat pump types. Compared to the past, higher capacity systems over 400 kW have been certificed. The cooling COP of the heat pump unit based on certification criteria showed higher value than the heating COP. It is highly recommended to revise the certified criteria values considering operating conditions individually. Most of ground source heat pump units have employed scroll type compressors and plate type heat exchangers with HFC refrigerant.