• 제목/요약/키워드: Humidity Aging

검색결과 122건 처리시간 0.028초

습식 인공열화 시 밀랍본 복제품의 제책 부위별 열화특성 (Studies on the Aging Characteristics in Different Parts of Beeswax-treated Duplicates during Humidified Artificial Aging)

  • 최경화;조정혜;강영석;양은정;정혜영
    • 펄프종이기술
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    • 제44권5호
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    • pp.72-79
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    • 2012
  • In this study, to understand the aging factor and mechanism in different partitions of the beeswax-treated volumes, the duplicated beeswax-treated volume was artificially aged at $80^{\circ}C$ of temperature and 65% of relative humidity and then a physical and optical properties of an aged volumes was analyzed. Also, the degraded components of the beeswax samples isolated from different partitions of aged volumes was measured using a gas chromatography/mass spectroscopy (GC/MS). In results, the surface of beeswax-treated volume which is primarily affected by a main aging factors such as light, oxygen, moisture was more deteriorated than the inside of that volume. However, unlike inside of the book volume which was made from paper, the inside of beeswax-treated volume wax was also considerably deteriorated. The inside of the beeswax-treated volume is largely unaffected by the oxygen and humidity during aging due to the water repellency and the air permeation resistance of beeswax. Therefore, it is confirmed that aging factors and mechanisms in the inside of the volume are different from thats of the outside of the volume. This fact was also verified by the results of GC/MS analysis of an beeswax samples which was sampled from different partitions of aged volumes. As result as GC/MS analysis of the beeswax extracted from the outside of the aged volume, the low molecular compounds with a carbon length of $C_9-C_{20}$ (fatty acid, etc) were increased and the compounds with a carbon length of above $C_{34}$ (ester, etc) were also increased. But the compounds with a chain length of $C_{21}-C_{36}$ (hydrocarbon, alcohol, etc) were decreased. In case of the aged beeswax of inside, the low molecular compounds with a carbon length of $C_9-C_{20}$ (fatty acid, etc) and the compounds with a chain length of $C_{21}-C_{36}$ (hydrocarbon, alcohol, etc) were increased. While, the compounds with a carbon length of above $C_{34}$ (ester, etc) were decreased.

숙성 조건 변화에 의한 흑마늘의 이화학적 특성변화 (Changes in Physicochemical Properties and by the Aging Conditions of Garlic)

  • 서보영
    • 한국산업융합학회 논문집
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    • 제25권1호
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    • pp.21-26
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    • 2022
  • When garlic is aged for a certain period of time while maintaining proper humidity, it causes a browning reaction by its own ingredients and enzymes. In this study, the physicochemical properties were analyzed by varying the temperature conditions for aging garlic. It was found that about 20% of the weight of garlic was reduced through the aging process. During the aging process, both samples showed the highest water content on the 10th day of aging, and the water content of the two samples was similar after the aging was completed. In the analysis of total sugar content change, AG1 (22.0±0.7 vs 21.4±0.6) showed a significantly higher sugar content on the 10th day of aging, but showed a tendency to gradually decrease thereafter, whereas AG2 showed a steady increase in sugar content during the aging process (18.7 < 21.4 < 21.7 < 22.3 < 23.7). The pH change that occurred during the aging process showed the most pH change on the 10th day. In AG1, the pH gradually decreased as the aging period increased, whereas in AG2, the pH increased significantly after the 10th day. In the analysis of browning, AG1 increased sharply on the 10th day and maintained the state, and AG2 showed a significant increase in browning according to the aging process. In conclusion, based on the results of this study, if various ripening temperature conditions are set, it is judged that it will play a positive role in improving the productivity of black garlic.

온·습도센서(BME 280 센서)를 이용한 PET/CT 장비의 항온 항습기 온·습도 평가 (Evaluation of Temperature and Humidity of a Thermo-Hygrostat of PET/CT Equipment using a Temperature and Humidity Sensor(BME 280))

  • 류찬주;김정아;김준수;윤근영;허승희;홍성종
    • 한국방사선학회논문지
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    • 제14권1호
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    • pp.15-22
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    • 2020
  • PET(Positron Emission Tomography)장치는 해부학적 정보를 얻기 위한 CT와 MRI의 장치를 PET 장치와 융합시킨 PET/CT나 PET/MRI 장치로 사용된다. 그렇기 때문에 일반 의료장비들과 비교하여 Gantry(촬영부 본체)의 길이가 늘어나고 내부의 공간이 넓어지는 원형(ring)타입의 구조로 제작된다. PET 장치의 구성요소 중 하나인 신틸레이터는 Gantry 안쪽에 위치하는데 온·습도 변화에 민감한 크리스탈 성분으로 되어있기 때문에 커다란 온도 변화로 인해 신틸레이터의 손상을 가져올 수 있다. 신틸레이터는 항온항습기로 PET장치가 설치되어 있는 공간에 온·습도를 유지하지만 이러한 PET 장치의 구조적 원인과 CT 장비에서 발생하는 열로 인한 Gantry 내부의 온·습도의 변화가 예상된다. 항온항습기를 가동하여 온·습도를 유지중인 PET/CT 장치의 Gantry 내부를 6개의 구역으로 나눈 후 각 구역에 Arduino 온·습도 센서인 Adafruit BME 280을 부착하여 출력 값을 분석했다. 각 6개 구역에서 센서를 이용해 측정한 평균 온·습도 값과 항온항습기의 평균 측정값을 비교하면 평균적으로 온도는 2.71℃ 상승, 습도는 21.5% 감소의 차이가 발생하였고, PET Gantry의 온·습도 측정값은 국내에서 지정한 정도 관리 범위에서 벗어나는 결과 값이 나왔다. 연구 결과를 통해 앞으로 지속적인 온·습도의 변화를 가진다면 PET Gantry 안에 장착된 신틸레이터의 노후화가 예상되므로 Gantry구조 내부의 온·습도를 적절히 유지하는 방안을 모색해야 한다.

옥외용 고분자 절연재료의 자외선 열화특성 연구 (A Study on the Ultraviolet Aging characteristics of Outdoor Polymeric Insulating Materials)

  • 김영성;이상진;박완기;정순욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1404-1406
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    • 1998
  • The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged by various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation. high temperature and humidity as well as water spray. These the aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. the experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as $Al(OH)_3$ improves tracking resistance and the $TiO_2$ is very effective in preventing degradation of silicone rubber surface from UV-ray.

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복합가속열화시험에 의한 폴리머 피뢰기의 경년특성 (Aging Characteristics of Polymer Lighting Arrester by Multi-Stress Accelerated Aging Test)

  • 송현석;이재봉;장상옥;한용희;오재형
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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    • pp.86-89
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    • 2004
  • Recently polymer arresters are being used widely but we don't have appropriate long term characteristics test methods. Therefore we need to develop special test facility to evaluate long term reliability of polymer arresters. It's polymeric housing can be degraded by environmental stress and the interface between housing and inner module can be affected by moisture absorption. This moisture absorption can cause leakage current and tracking in the interface. We developed multi stress accelerated ageing test facility to simulate field conditions including UV, temperature, humidity, voltage, salt fog and rain. In addition, we carried out field exposure test at the outdoor test yard and characteristics analysis of field operated specimens to evaluate accelerating factor of this accelerated aging test.

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Comparison of Drying Yield, Meat Quality, Oxidation Stability and Sensory Properties of Bone-in Shell Loin Cut by Different Dry-aging Conditions

  • Cho, Soohyun;Kang, Sun-Moon;Kim, Yun-Seok;Kim, Young-Chun;Ba, Hoa Van;Seo, Hyun-Woo;Lee, Eun-Mi;Seong, Pil-Nam;Kim, Jin-Hyoung
    • 한국축산식품학회지
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    • 제38권6호
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    • pp.1131-1143
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    • 2018
  • This study aimed to investigate the drying yield, meat quality, oxidation stability and sensory properties of Hanwoo beef loin subjected to different dry-aging conditions. A total of 54 Hanwoo beef loins (bone-in, $6^{th}-13^{th}$ ribs) with fat cover at 2 d postmortem were assigned to four groups and hung in a dry-aging room at a controlled temperature ($2^{\circ}C-4^{\circ}C$), humidity (65%-85%) and air velocity (3 m/s). Four treatment conditions were tested; the respective temperature, humidity and treatment duration are as follows: T1, $2^{\circ}C$, 85%, 60 d; T2, $2^{\circ}C$, 65%, $20d+2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 20 d; T3, $2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 40 d; T4, $4^{\circ}C$, 85%, 60 d. The drying yield, total aerobic counts and fat contents increased, whereas the moisture content, meat color (CIE $L^*$, $a^*$, and $b^*$), and Warner-Bratzler shear force values decreased significantly during the aging period for all treatments (p<0.05). The cooking loss (%) did not change significantly until 40 d, and it was significantly higher in T1 and T4 than in T2 and T3 at 60 d (p<0.05). The water-holding capacity, pH and lipid oxidation [thiobarbituric acid reactive substance (TBARS) values] increased during aging (p<0.05). The sensory scores for tenderness, juiciness, flavor, and overall acceptability of dry-aged loin muscles increased as the aging period increased. T2 and T3 had significantly higher sensory scores and T1 had significantly lower scores for tenderness, juiciness, flavor, and overall acceptability at 20, 40, and 60 d for loin muscles (p<0.05).

Influences of Aging Methods and Temperature on Meat Quality of Pork Belly from Purebred Berkshire and Crossbred Landrace×Yorkshire×Duroc (LYD) Pigs

  • Jin, Sang-Keun;Yim, Dong Gyun
    • 한국축산식품학회지
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    • 제42권3호
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    • pp.398-410
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    • 2022
  • We studied effects of aging methods and temperature on the physical, chemical, and amino acid composition of pork belly from Berkshire and Landrace×Yorkshire×Duroc (LYD) swine. Pork belly samples were assigned randomly to breed groups (Berkshire and LYD), aging temperature groups (0℃ and 9℃), and aging method groups. One samples of vacuum-packaged hanging pork bellies were hung in a refrigerated cooler with 83±2.0% humidity, while the other samples were immersed in a 3.5% salt solution in a vacuum package and subsequently stored in the same cooler for 2 weeks. LYD pork had lower pH and purge loss and higher lightness values than those of Berkshire pork (p<0.05). Moreover, thiobarbituric acid reactive substances and hardness values of LYD pork were lower than those of Berkshire pork after aging (p<0.05). Berkshire pork had a higher level of flavorful amino acids than LYD pork did during aging (p<0.05). Bellies aged at elevated temperatures for two weeks had higher volatile basic nitrogen. However, significantly higher percentages of flavorful and sweet taste amino acids were observed in bellies aged at 9℃ compared to those aged at 0℃ for 2 weeks. Moisture content was higher in immersed samples than hanging samples after two weeks of aging (p<0.05). Hanging pork bellies exhibited higher texture profiles than immersed pork bellies at two weeks (p<0.05). We concluded that breeds, aging temperature, and methods affected most quality attributes of pork belly.

안전한 건식 숙성육 제조를 위한 미생물 위해평가 및 HACCP 적용 방안 (Microbial Risk Assessment and HACCP Plan for the Safe Production of Dry Aged Meat)

  • 오혜민;이현정;조철훈;윤요한
    • 급식외식위생학회지
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    • 제3권1호
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    • pp.8-18
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    • 2022
  • Dry-aging is one of the traditional aging processes, especially for beef. This aging process is being popular, because it produces unique brown/roasted flavor and texture that consumers prefer. However, as it is exposed to outside without packaging food safety concerns have been raised. The objective of this study was to investigate the presence of total aerobic bacteria (TAB) and pathogenic bacteria in manufacturing environment and suggest the safety management plan for the production of dry-aged meat. Surface samples from 66 environmental and 6 beef carcass samples were collected. According to the monitoring results, the contamination levels of TAB were in the order of shelves (5.4±1.1 Log CFU/cm2), cotton gloves (2.9±0.2 Log CFU/cm2), and door knobs (2.8±0.4 Log CFU/cm2) in the dry-aging room. In the door knobs, the level of mold was higher than that of yeast. These results indicate that the mold spores may be cross-contaminated with environmental factors inside the aging room. The risk factors that may occur during the manufacturing process were presented and possibility of risk was determined. From the aspect of microbiology, aging and trimming steps were determined as the critical control points. The temperature of the aging room should be maintained below 10℃ and the humidity below 75-85%. Based on the monitoring and the risk assessment of the dry-aging process, we prepared the safety management plan for the production of dry-aged meat, and it should be useful in improving the food safety of dry-aged meat.

종이 기록물의 대기 중 유해물질에 의한 가속 열화 특성 연구 (Study on Accelerated Aging Characteristics of Paper-Records by Air Pollutants)

  • 박미선;정소윤;황지현;김형진;김신도
    • 펄프종이기술
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    • 제46권4호
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    • pp.76-84
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    • 2014
  • Preventive conservation is one of most important issues in the field of conservation for paper-records. Many researchers have been studied environmental factors such as effects of humidity, temperature, biological attack and air pollutants. Air pollutants strongly associated with oxidative and hydrolytic degradation of cellulose. It is important to control air pollutants in storage environment to improve stabilities of conservation environment. Four paper samples have been analyzed for their accelerated aging characteristics by air pollutants, sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide. Physical and optical properties and weight molar masses(Mw) showed that interactions between air pollutants and paper sample. Nitrogen dioxide, ozone caused severe damage to cellulose in paper by hydrolytic and oxidative decompositions during aging.

22kV 전력케이블의 열화 판정에 관한 연구 (A Study on the Remain Life with Aging in 22kV CV cable)

  • 이관우;목영수;김보경;박복기;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.19-21
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    • 2003
  • In this paper, we studied on life-decision of underground cable of live-lines state. As all equipments have been wear, underground cables decided design-life on the whole 30 years because underground cable have been occurred aging as time goes. CV cable has been become about 30 years after installation in the South Korea, is come to a important point of time with estimation about life. Study target cable is 22 kV CV cables in this point of view and installation cable is about 10 years before and behind. Measurement method used dc leakage method of live-lines state that applied voltage of 50V in neutral point and data is analyzing result that is measured during 5 years. In this result, insulation resistance could confirm that change according to season and cause is effect of humidity, seasons and load current. Also, according as data is gone aging, insulation resistance by Weibull distribution could confirm functionally its decrease. As a result, the aging speed of cable that water tree is gone could confirm fastness very. Numerical analysis result, cable that water tree is not gone could confirm that life of cable that has passed 10 years remains about $10{\sim}20$ years.

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