• Title/Summary/Keyword: Humidity of laboratory

Search Result 257, Processing Time 0.028 seconds

Effects of Temperature and Humidity on Fungal Occurrence in Dried Red Pepper during Storage

  • Kim, Sosoo;Baek, Seul Gi;Hung, Nguyen Bao;Kim, Se-Ri;Jang, Ja Yeong;Kim, Jeomsoon;Lee, Theresa
    • Research in Plant Disease
    • /
    • v.27 no.4
    • /
    • pp.155-163
    • /
    • 2021
  • Dried red peppers are frequently contaminated with mycotoxins during storage. To determine the effect of storage environments on fungal occurrence and subsequent mycotoxin accumulation in dried red peppers, we monitored red pepper powder and whole fruit samples for fungal occurrence under various temperatures and relative humidity (RH) conditions during 340 days. Fungal occurrences fluctuated in both pepper forms throughout the storage but they were higher in pepper powder than whole one, higher under low temperatures (-20℃, 0℃, or 4℃) than others (10℃, 25℃, or 30℃), and higher under RH 93% than RH 51% and 69% in both peppers. The samples exhibiting high fungal occurrences were associated mainly with dominant species such as Aspergillussydowii, Penicillium solitum, P. roqueforti, P. polonicum, or P. chrysogenum. Mycotoxigenic species, including A. flavus, A. ochraceus, A. westerdijkiae, A. tubingensis, and P. citrinum, were also detected throughout the samples. Although mycotoxins were not detected in the samples, mycotoxigenic potential of A. flavus, A. ochraceus, and A. westerdijkiae isolates were confirmed. These results show that low temperatures (-20℃, 0℃, or 4℃) and/or high surrounding RH (>93%) are not safe environments for storage of dried red peppers as fungal growth can occur under these conditions.

Inactivation of Indoor Airborne Fungi Using Cold Atmospheric Pressure Plasma (저온 대기압 플라즈마의 실내공기 중 곰팡이 생장억제 효과)

  • Paik, Namwon;Heo, Sungmin;Lee, Ilyoung
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.29 no.3
    • /
    • pp.351-357
    • /
    • 2019
  • Objectives: The objectives of this study were to investigate fungal contamination in a 31-year old university building in Seoul, Korea, and to study the inactivation of fungi using cold atmospheric pressure plasma(CAP). Methods: To investigate the fungal contamination in a university building, air samples were collected from five locations in the building, including two study rooms, a storage room, a laboratory, and a basement. The sampling was performed in a dry season(February to April) and in a wet season(July). To study the inactivation efficacy of fungi by CAP, airborne fungal concentrations were measured before and after the operation of the CAP generator. Results: Humidity was an important factor affecting fungal growth. The airborne fungal concentrations determined in the wet season(July) were significantly higher than those determined in the dry season(February to April). In the basement, the values determined in the dry and wet season were 319 and $3,403CFU/m^3$, respectively. The inactivation efficiency of fungi by CAP was 83-90% over five to nine days of operation. Conclusions: The university building was highly contaminated by airborne fungi, especially in summer. It is concluded that humidity is an important factor affecting fungal growth and CAP is a highly useful technique for inactivation of indoor airborne fungi.

The Distribution of Clothing Microclimate on the Upper Body (상반신에서의 의복기후분포)

  • Kim, Yang-Weon;Hong, Kyng-Hi
    • Korean Journal of Human Ecology
    • /
    • v.15 no.4
    • /
    • pp.647-650
    • /
    • 2006
  • The factors affecting clothing comfort are temperature, humidity, and air velocity of clothing microclimate which is the temperature and the humidity between the skin surface and the innermost garment, clothing pressure and clothing texture to the skin. This study was designed to estimate the distribution of clothing microclimate on the upper body. All the data of this study were collected from volunteered male subjects in the controlled climate chamber laboratory in which the temperature was $25\pm1^{\circ}C$, the relative humidity $50\pm5%$, and the air velocity 30cm/sec. All subjects should wear long-sleeved inner wear and pants woven in 100% cotton. Clothing microclimate temperature at 16 sites on the chest and 16 sites on the back was measured. The results were as follows: the distribution of the clothing microclimate temperature on the upper body was $30.6\sim34.7^{\circ}C$ on the breast and $31.5\sim35.4^{\circ}C$ on the back. While a mean temperature on the chest was 33.3$^{\circ}C$, it was 33.1$^{\circ}C$ on the back.

  • PDF

Anoxia Techniques to Eradicate Insects for Conservation of Cultural Properties in Museums (박물관에서의 저산소 농도를 이용한 살충 기술)

  • Oh, Joon-Suk
    • Journal of Conservation Science
    • /
    • v.27 no.2
    • /
    • pp.231-241
    • /
    • 2011
  • Anoxia Treatment using inert gas like nitrogen and argon has been used to eradicate insects successfully in museums as alternative of methyl bromide and toxic insecticide. Killing efficacy of insect for anoxia treatment is depend on species of insects, oxygen concentration, temperature, relative humidity and gas. It is possible to kill museum insects which are most tolerant in anoxia environment, within 1 month below 0.03% of oxygen concentration in temperature $15{\sim}25^{\circ}C$ and relative humidity 40~60% of museum environment. And various systems like bag, tent, bubble and chamber depending on size and quantity of objects, are used.

Validity Periods of Sterilization Products: Focus on Packing Materials and Storage Environments (멸균물품의 유효기간에 관한 연구: 포장재와 보관환경을 중심으로)

  • Park, Hyun Hee;Lee, Kwang Ok
    • Journal of muscle and joint health
    • /
    • v.30 no.3
    • /
    • pp.263-272
    • /
    • 2023
  • Purpose: The aim of this study was to provide a scientific basis for shelf life and re-establish the shelf life in a hospital environment by investigating the validity periods of various packaging materials. Methods: We selected six departments to store sterilized items, prepared 482 sterilized items, and stored them for 12 months. Each sample was tested using a microbiological culture in the laboratory every two weeks. When the result was positive, the sample was considered contaminated. The temperature and relative humidity were measured using an automatic control system to investigate the storage environment during the study period. Results: Except for two samples, which were positive in the 22nd and 28th weeks, 480 samples were negative. The temperature and relative humidity of the sample storage area were measured every week. The annual average temperature was 23.6±1.6℃, and the mean relative humidity was 35.1±15.2%. The cabinets used in this study were the two-open and four-closed types. Conclusion: This study confirmed the validity of the expiration date in a hospital environment. Based on the results, the nonwoven fabric remained sterile for more than nine months. No case of contamination of the paper-plastic pouch packaging was observed, owing to the microbial culture for two months.

Water Sorption/Desorption Kinetics and Convective Drying of Eucalyptus globulus Wood

  • AMER, Mahyoub;KABOUCHI, Bousselham;El ALAMI, Salah;AZIZE, Brahim;RAHOUTI, Mohamed;FAMIRI, Abderrahim;FIDAH, Abdelwahed
    • Journal of the Korean Wood Science and Technology
    • /
    • v.47 no.5
    • /
    • pp.557-566
    • /
    • 2019
  • Radial and tangential water diffusion in Eucalyptus globulus wood was investigated using three mature trees from a forest in Khemis Sahel (North Morocco). Absorption and desorption kinetics experiments were conducted at ambient temperature ($25^{\circ}C$) and $30^{\circ}C$, respectively, and a relative humidity of 60%. The diffusion coefficients in the two directions were determined under imposed hygrothermal conditions; they were greater in the radial direction for the absorption as well as desorption processes. Convective drying under load, preceded by reconditioning and followed up by balancing, revealed the drying conditions that corresponded to the appropriate drying schedules for E. globulus wood. This was verified by measuring the cracks and bowsbefore and after drying of boards.

Direct Observation of Radiative Flux in the Southern Yellow Sea

  • Lu, Lian-Gang;Yu, Fei;Diao, Xinyuan;Guo, Jingsong;Wang, Huiwu;Wei, Chuanjie
    • Ocean Science Journal
    • /
    • v.43 no.2
    • /
    • pp.115-126
    • /
    • 2008
  • Direct measurements of four radiative components at air-sea boundary layer were conducted in the southern Yellow Sea during three cruises (seasons) in 2007. Simultaneous observations of meteorological (cloud cover, air temperature and humidity) and oceanographic (sea surface temperature) parameters were carried out. Observational results of radiative fluxes and meteorological and oceanographic parameters are presented. Mean diurnal cycles of four radiative components, net radiation, and sea surface albedo are calculated to achieve averages in different seasons. Net radiative fluxes in three seasons (winter, spring, autumn) are 8, 146, $60\;W/m^2$, respectively. Comparisons between the observed radiative fluxes and those estimated with formulas are taken.

A Study on the Surface Characteristics of Phenolic Resin by Water Treatment (수처리에 의한 페놀수지의 표면특성에 관한 연구)

  • Choi, Chung-Seog;Shong, Kil-Mok;Kim, Hyung-Rae;Kim, Dong-Woo;Kim, Hyang-Kon;Kim, Dong-Ook
    • Proceedings of the KIEE Conference
    • /
    • 2002.07c
    • /
    • pp.1431-1433
    • /
    • 2002
  • In this paper, we studied the characteristics of surface structure of phenolic resin by water treatment. Phenolic resin which is used as indoor insulators is easily deteriorated by humidity. Water treated sample for 200 hours is subjected to the penetration of water and cracked partially. Water treated sample for 400 hours is found more cracks than that for 200 hours. The initial leakage current of virgin sample is 0.11A, that of water treated sample for 200 hours is 0.07A, and that of water treated sample for 400 hours is 0.05A. FT-IR analysis indicates that absorption peak of carbonyl group appears in virgin sample, but the absorption peak does not appear in water treated sample for 200 hours.

  • PDF

Expression of Heterotic Genetic Interaction among Multivoltine Recurrent Backcross/Congenic Lines for Higher Shell Weight of Silkworm, Bombyx mori L.

  • Verma, A.K.;Chattopadhyay, G.K.;Sengupta, M.;Sengupta, A.K.;Das, S.K.;Urs, S.Raje
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.7 no.1
    • /
    • pp.21-27
    • /
    • 2003
  • Manifestation of heterotic genetic interaction was studied in different hybrids made between multivoltine recurrent backcross (RBL)/congenic lines (Con. L) during unfavourable season when temperature and relative humidity are > $30^{\circ}C$ and 86%, respectively. A few number of silkworm race or strain or breed like Nistari (N + p or Np) can sustain the temperature above 3$0^{\circ}C$ and RH above 86%. The present heterosis study screened a hybrid i.e., CB$_{5}$Lm5RBL1M$_{6}$DPC-LmE$^1$RBL and its reciprocal provided heterobeltiotic effect on survival by number and pupation rate at a magnitude of 20% (p < 0.01) and yield by weight of 10% (p < 0.01). Beside all the hybrids expressed heterosis over check - Nistari (N + p) with better quality silk. Therefore, aforesaid hybrid may be useful for utilization at commercial level during adverse seasons of West Bengal.gal.

Evaluation Technology of Electrical and reliableility Characteristics for Outdoor Polymer Insulator Materials (폴리머 절연물 소재의 전기적 밀 복합열화 특성평가 기술)

  • Ahn, Myeong-Sang;Park, Hoy-Yul;Na, Moon-Kyeong
    • Proceedings of the KIEE Conference
    • /
    • 2006.07c
    • /
    • pp.1343-1344
    • /
    • 2006
  • There have been numerous accelerated aging laboratory tests for evaluating suitability of polymeric materials and devices. Aging test for materials and its full scale device has been conducted. Service experience plays a key role in the utility section of composite insulators. A meaningful and reliable accelerated aging test is needed for evaluating composite insulator. During the service these insulators are subjected to aging stress such as humidity, pollution, and electrical field, and erosion and tracking of the weathershed occurs. This paper presents the criteria of reliability evaluation and evaluation facilities for 22.9 kV suspension composite insulator. We adopt the criteria of reliability evaluation consist of two test methods. One is CEA tracking wheel test for examining the tracking and erosion performance of composite insulator. The other is multi-stress aging test for examining effects of environmental factors such as UV, temperature, humidity, etc on composite insulator.

  • PDF