• 제목/요약/키워드: Dry heat

검색결과 919건 처리시간 0.026초

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
    • 한국식품과학회지
    • /
    • 제52권5호
    • /
    • pp.503-509
    • /
    • 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.

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

  • 한봉호
    • 한국수산과학회지
    • /
    • 제10권3호
    • /
    • pp.145-149
    • /
    • 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.

  • PDF

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

  • 송진희;이동윤;신동일;전현도;박철용;김상균
    • 대한건축학회논문집:구조계
    • /
    • 제35권6호
    • /
    • pp.153-164
    • /
    • 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.

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

  • 장철용;이나은;엄은정
    • 한국태양에너지학회:학술대회논문집
    • /
    • 한국태양에너지학회 2009년도 추계학술발표대회 논문집
    • /
    • pp.241-245
    • /
    • 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.

  • PDF

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

  • 유영준;민성기;최상민
    • 한국연소학회:학술대회논문집
    • /
    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
    • /
    • pp.233-236
    • /
    • 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.

  • PDF

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
    • /
    • 제17권2호
    • /
    • pp.61-67
    • /
    • 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.

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

  • 이승엽;안정호;김효진;배종향;은무영
    • 생물환경조절학회지
    • /
    • 제15권4호
    • /
    • pp.421-427
    • /
    • 2006
  • 밀양 23호/기호벼 유래 164 RILs($F_{17}$)을 이용하여, 종자의 휴면과 관련이 있는 수발아 저항성, 건열 저항성 및 종자수명을 검정하고, 이들 상호간 상관관계를 조사하였다. 출수 40일째에 밀양23호와 기호벼의 수발아율은 0%, 7%이었고, M/G RILs은 0$\sim$50.9%의 범위를 보였으며, 평균 3.2%였다. $90^{\circ}C$, 24시간 건열처리후 밀양23호와 기호벼는 99.2%, 37.6%의 발아율을 보였고, $T_{50}$은 2.7일, 12.9일로 유의한 차이를 보였으며, M/G RILs의 평균 발아율은 72.4%였다. 상온저장 한 종자수명은 밀양23호는 수확후 3.5년까지도 80% 이상의 종자 발아율을 유지하였으나, 기호벼는 18개월 후부터 급격히 발아력이 감소하여(30%이하), 42개월 후 발아력을 완전히 상실하였다. M/G RILs의 종자활력은 수확후 42개월까지 71계통이 90%이상의 발아율을 보였다. 수발아 저항성, 건열 저항성 및 종자수명은 밀양 23호와 기호벼 간에 뚜렷한 품종간 차이를 보였으며, M/G RILs은 양친의 중간값에 가까운 평균값을 보였다. 건열저항성과 종자수명 간에는 고도로 유의한 정의 상관관계를 보였고, 수발아와 종자수명, 수발아와 건열저항성 간에는 부의 상관관계가 성립하였다.

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

  • 이은진;박종현
    • 한국축산식품학회지
    • /
    • 제30권3호
    • /
    • pp.479-486
    • /
    • 2010
  • 국내의 건조분말 식품에서 분리한 Cronobacter spp.의 건조내성에 따른 열, 살균소독제, 항생제에 대한 내성특성 분석하여 Cronobacter spp.을 제어하는 효과적인 방법을 연구하고자 하였다. 분리된 37개의 건조저항 균주, 7개의 건조민감 균주, 그리고 68개의 중간그룹의 균주 총 112개에 대하여 분석한 결과 건조내성을 가지고 있는 Cronobacter spp.는 열에 대해서도 저항성이 큰 것으로 나타났다. 따라서 조제분유등의 건조 스트레스에 노출되어 살아남은 Cronobacter spp.는 열 스트레스에서도 높은 내성을 보일수 있을 것으로 사료된다. 살균소독제를 이용한 Cronobacter spp.의 제어효능은 sodium hypochlorite는 15-25 ppm와 benzalkonium chloride는 5-15 ppm 농도에서 5 log CFU/mL 살균 효과가 있었다. Albumin으로 3%(w/v)오염시킨 부유세균의 살균력은 건조내성 균주와 건조민감 균주 모두에서 오염전과 비슷하여 유기물 오염상태에서도 살균소독제 효능에는 큰 영향을 주고 있지 않음을 알 수가 있었다. 그리고 항생제 내성은 $\beta$-lactam 계열의 ampicillin에 대하여 약 90% 분리주가 64-128 ppm의 농도에서 최소저해 농도를 보여 주었다. Aminoglycoside 계열의 kanamycin과 Gram(-) spectrum의 nalidixic acid에서 4 ppm의 가장 낮은 내성을 보였다. 건조민감 균주과 건조내성 균주의 최소저해농도 경우 전반적으로 모든 항생제에 대해서 건조 내성이 높은 균주가 더 큰 항생제 내성을 지니고 있는 것으로 나타났다. 따라서 분리 Cronobacter spp.의 건조내성이 열과 항생제의 저항성과 관련이 있는 것으로 보인다. 그러므로 조제분유와 같은 분말식품과 그 원료의 오염 Cronobacter spp.의 살균제어에 더 강력한 처리가 필요할 것으로 보인다.

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

  • 이재화;김주영;김완기
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
    • /
    • pp.255-257
    • /
    • 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%.

  • PDF

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

  • 유승엽;최나래;오승윤;박수정;주종천
    • 동의생리병리학회지
    • /
    • 제30권1호
    • /
    • pp.14-19
    • /
    • 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.