• Title/Summary/Keyword: dry heat

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Variations in total phenols, total anthocyanins, and antioxidant activity levels in black chokeberry (Aronia melanocarpa) fruits subjected to dry and moist heat treatments

  • Kim, Hekap;Mai, Thu Thi Hoai
    • Korean Journal of Food Science and Technology
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    • v.52 no.5
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    • pp.503-509
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    • 2020
  • The present study investigated the effects of dry and moist heat treatments on total phenols, total anthocyanins, and antioxidant activity levels in black chokeberry (Aronia melanocarpa) fruits. Lyophilized chokeberry powder samples were heated in a drying oven at 60, 100, 160, 180, and 200℃ for 20, 40, or 60 min. Finely ground fresh chokeberry fruits were heated in water at 60, 80, and 100℃ for 20 min, and bioactive compound and antioxidant activity levels were measured. The bioactive compounds and antioxidant activity decreased with increasing temperature and treatment duration. Antioxidant activity was preserved at 160℃ or lower without significant loss for dry heating, whereas moist heat treatment increased both bioactive compounds and antioxidant activity with increasing temperature.

THERMAL RESISTANCE OF BACTERIAL SPORES TO DRY HEAT (세균포자의 건열에 대한 열저항성)

  • HAN Bong-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.10 no.3
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    • pp.145-149
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    • 1977
  • Thermal resistance of dried bacterial spores against dry heat was determined. Spare suspensions of Bacillus subtilis var. niger ATCC 9372, Bacillus stearothermophilus Oxoid Code BR 23 and Clostridium sporogenes ATCC 19404 were located on aluminium strips, dried in electric oven under vacuum at room temperature for 10 minutes. The aluminium strips were laid in the middle of gas flow (hot air and superheated steam) with the velocity of 6 m/sec and heated at $120^{\circ}C$ for 180 seconds. The calculated D-values showed that there were no remarkable differences in the heat resistance of bacterial spares between $R.H.\leqq0.012$ and R. H.=0.51. Furthermore the thermal resistance of B. subtilis spores to dry heat was greater than that of B. stearothermophilus.

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Evaluation of Building Envelope Performance of a Dry Exterior Insulation System Using Truss Insulation Frame (트러스 단열 프레임을 이용한 건식 외단열 시스템의 외피 종합 성능 평가)

  • Song, Jin-Hee;Lee, Dong-Yun;Shin, Dong-Il;Jun, Hyun-Do;Park, Cheol-Yong;Kim, Sang-Kyun
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.6
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    • pp.153-164
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    • 2019
  • The presence of thermal bridges in a building envelope cause additional heat loss which increases the heating energy. Given that a higher building insulation performance is required in these cases, the heat loss via thermal bridges is a high proportion of the total heat energy consumption of a building. For the dry exterior insulation system that uses mullions and transoms to fix insulation and exterior materials such as stone and metal sheet, the occurrence of thermal bridges at mullions and transoms is one of the main reasons for heat loss. In this study, a dry exterior insulation system using the truss insulation frame (TIF) was proposed as an alternative to metal mullions. To evaluate the building envelope performance, structural, air-leakage, water-leakage, fire-resistance, thermal, and condensation risk tests were conducted. In addition, the annual energy consumption associated with heating and cooling was calculated, including the linear thermal transmittance of the thermal bridges. As a result, the dry exterior insulation system using TIF achieved the allowable value for all tests. It was also determined that the annual heating load of a building was reduced by 36.7 % when the TIF dry exterior insulation system was used, relative to the dry exterior insulation system using steel pipes without additional insulations.

A Comparison Analysis on Thermal Performance According to Shape of Steel Stud Applied to Steel House (스틸 하우스 적용 스틸 스터드의 형상에 따른 단열성능 비교 연구)

  • Jang, Cheol-Yong;Lee, Na-Eun;Um, Eun-Jung
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.241-245
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    • 2009
  • The dry wall using steel stud is used to buildings in the inside and outside of the country because it has the merit that application is possible to various architecture. The purpose of this study is to measure thermal performance of dry wall which uses steel stud transformed one by using measurement equipment to decrease heat bridge of steel stud and ensure heat performance as dry wall. As a comparative performance test result, dry wall which uses steel stud transformed one has a performance enhancement compare with the dry wall using general steel stud.

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An Analytical Study on a Performance Estimation of an Evaporative Heat Exchanger having Mini Channel (미세채널형 증발열교환기의 성능에 관한 해석적 연구)

  • Yoo, Youngjoon;Min, Seongki;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.233-236
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    • 2012
  • In order to estimate the efficiency of an evaporative heat exchanger having mini channel, the equations to calculate heat exchanger properties, those are air temperatures and water temperatures etc, are derived from the governing equations based on the Navier-Stokes equation, even though there are several assumptions to make problem simplify. There are three heat transfer zones at the mini channel heat exchanger depending on the water condition. So, there are three governing equations and solutions to calculate the properties. As a results of this study, the equations to calculate a saturation point and a dry point are derived to evaluate an evaporative heat exchanger having micro channel. It is supposed to predict the performance and evaluate a mini channel heat exchanger.

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Thermal Performance of a Finned-tube Heat Exchanger used in Condensing Gas Boiler

  • Kang, Hie-Chan;Lim, Bok-Bin;Lee, Jung-Man;Kim, Moo-Han
    • International Journal of Air-Conditioning and Refrigeration
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    • v.17 no.2
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    • pp.61-67
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    • 2009
  • In the present study, an experiment was conducted to investigate the heat and mass transfer performance of heat exchangers used in the condensing gas boiler. Two types of spiral circular fin-tube heat exchangers and a plain tube were tested in the flue gas of propane and dry air. Heat and mass transfer coefficients were measured and compared with the previous correlations. The experimental data for the sensible heat transfer of the plain tube reasonably agreed with the previous correlations for dry air and flue gas. However, the mass transfer coefficient of the plain tube was greater than the previous correlations. The pH, $NO_x$, and $SO_x$ data of condensate were provided.

Relationships among Viviporous Germination, Dry-heat Tolerance and Seed Longevity in Milyang 23/Gihobyeo RILs (벼 밀양 23호$\times$기호벼의 재조합 자식계통에서 수발아성,건열 저항성 및 종자수명간 상관관계)

  • Lee, Seung-Yeob;Ahn, Jeong-Ho;Kim, Hyo-Jin;Bae, Jong-Hyang;Eun, Moo-Young
    • Journal of Bio-Environment Control
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    • v.15 no.4
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    • pp.421-427
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    • 2006
  • To investigate the relationships among the traits related seed dormancy in rice, viviparous germination, dry-heat tolerance and seed longevity were tested using 164 M/G RILs ($F_{17}$) derived from the cross between Milyang 23 (Indica/Japonica) and Gihobyeo (Japonica). At 40 days after heading, the viviparous germination rates of Milyang 23 and Gihobyeo were 0.0 and 7.0%, respectively. The averaged viviparous germination rate of 164 MIG RILs was 3.2%, and their range was from 0.0 to 50.9%. In dry-heat treatment at $90^{\circ}C$ for 24 h followed by the pre-drying at $40^{\circ}C$ for 2 days, Milyang 23 showed higher germinability (98.6%,2.7 days to $T_{50}$) than Gihobyeo (37.6%, 12.9 days to $T_{50}$), and the mean germination rate of 164 M/G RILs was 72.4%. In 54 months after harvest, the germinability in Milyang 23 and Gihobyeo were 90% and 0%, and 71 lines among 164 M/G RILs showed the germinability over 90%. The relationship between seed longevity and dry-heat tolerance was linearly correlated with high positive correlation coefficient. The relationships between seed longevity and viviparous germination, and viviparous germination and dry-heat tolerance were linearly correlated with high negative correlation coefficient. Milyang 23 had higher tolerance against high dry-heat, viviparous germination and long-term storage than Gihobyeo, and 164 M/G RILs showed the medium values of parents.

Biocontrol of Isolated Cronobacter spp. (Enterobacter sakazakii) by Heat, Sanitizer, and Antibiotic (열, 살균소독제, 항생제에 의한 분리 Cronobacter spp. (Enterobacter sakazakii) 제어)

  • Lee, Eun-Jin;Park, Jong-Hyun
    • Food Science of Animal Resources
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    • v.30 no.3
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    • pp.479-486
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    • 2010
  • Tolerance against heat, sanitizers, and antibiotics of 112 Cronobacter isolates classified by desiccation was determined to permit effective biocontrol in powdered foods. The isolates were classified into three groups: dry-tolerant (n=37), dry-sensitive (n=7), and dry-intermediate (n=68). The strains that were highly tolerant to drying also showed high heat tolerance that they seemed to have high tolerance to heat after dry stress in powdered foods like infant formula. Sodium hypochlorite and benzalkonium chloride concentrations necessary to achieve a 5-log reduction in viable counts (CFU/mL) were 15-25 ppm and 5-15 ppm, respectively. However, there was little difference of the efficacy of these sanitizers between dry-sensitive and -tolerant strains for planktonic cells suspended in 3% albumin. The minimal inhibition concentration (MIC) of $\beta$-lactam ampicillin was 64-128 ppm for 90% of the strains. The isolates were consistently sensitive to kanamycin and naldixic acid (MIC=4 ppm). Dry-tolerant strains displayed more antibiotic resistance than dry-sensitive strains. The results indicate that dry-tolerant Cronobacter isolates often possess heat and antibiotic resistance, indicated the need for potent sterilization treatments of powdered foods.

Hardening Properties of Hardener-Free Epoxy-Modified Mortars by Curing Conditions (양생조건에 따른 경화제 무첨가 에폭시수지 혼입 PMM의 경화특성)

  • Lee, Jae-Hwa;Kim, Joo-Young;Kim, Wan-Ki
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.255-257
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    • 2012
  • Epoxy resin without any hardener can harden in the presence of hydroxide ions in cement mortars and concretes at ambient temperature. The purpose of present study is to examine the hardening properties of hardener-free epoxy-modified mortars by curing conditions. The hardener-free epoxy-modified mortars using diglycidyl ether of A epoxy resin are prepared with various polymer-cement ratios, and subjected to initial moist/dry curing, initial steam(90℃) curing, initial steam/heat(80℃, 100℃) curing.As a result, degree of hardening of epoxy resin in initial moist/dry cured, initial steam cured and initial steam/heat(80℃) cured hardener-free epoxy-modified mortars is decreased with increasing polymer-cement ratio. However, it is markedly improved with additional dry-curing periods. On the other hand, regardless of the polymer-cement ratio and dry curing periods, degree of hardening of hardener-free epoxy-modified mortars with initial steam/heat(100℃) cure is over 95%.

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Study on the Pathology of Taeeumin Prescription in Sasang Constitutional Medicine (태음인 처방의 사상의학적 병리 연구)

  • Ryu, Seung Yeob;Choi, Na Rae;Oh, Seung Yun;Park, Soo Jung;Joo, Jong Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.1
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    • pp.14-19
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    • 2016
  • This study was designed to define the efficacy of prescriptions of Taeeumin in Sasang constitutional medicine. The twenty four prescriptions registered in Donguisusebowon Sinchuk edition written by Je-ma Lee in 1901 are the targets of this paper. We searched and analyzed original text such as Donguisusebowon Sinchuk edition written in 1901, Donguisusebowon Gabo edition written in 1894, Donguisusebowon Sansang Chobongwon, and posthumous manuscripts left by Je-ma Lee published by the Ministry of Health of North Korea. The pathology of the Taeeumin is classified into four mechanisms those are Esophagus-Cold (Wiwanhan), Cold Lung-Dry (HanpaeJo), Liver-Heat (Ganyeol), and Heat Lung-Dry (YeolpaeJo). The prescriptions of Taeeumin regulate four mechanisms. Twenty four prescriptions of Taeeumin regulate the mechanisms of Wiwanhan, HanpaeJo, Ganyeol, YeolpaeJo and correct the energy-fluid pathology of Taeeumin.