• Title/Summary/Keyword: total temperature

Search Result 6,957, Processing Time 0.043 seconds

Influence of Temperature Cycling on the Production of Aflatoxin in Solid Media (固體培地에서 Aflatoxin생성에 미치는 Temperature Cycling의 影響)

  • 정덕화;정영철;성낙개
    • Journal of Environmental Health Sciences
    • /
    • v.12 no.1
    • /
    • pp.39-45
    • /
    • 1986
  • This study was designed to observe the effect of temperature cycling on the production of aflatoxin by Aspergillus parasiticus R-716 in rice, barley, peanut and soybean. In those media, temperature cycling resulted in more total aflatoxin production by the strain of R-716 than constant incubation at $28{\circ}$C and natural condition did. Especially, high level of total aflatoxin ($1826{\mu}g$/30g) in rice medium at temperature cycling was produced. The intensity of yellow color of chloroform extracts correlated with the concentration of aflatoxin, and the ratio of aflatoxin $B_1$ to aflatoxin $B_2, G_1, G_2$ is lower at temperature cycling condition than at $28{\circ}$C.

  • PDF

A Study on the Errors in Skin Friction Measurements due to Surface Temperature Mismatch (표면온도 차이에 의한 표면마찰력 측정 오차에 대한 연구)

  • 백승욱
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.3 no.2
    • /
    • pp.213-218
    • /
    • 2000
  • An experimental study was performed to investigate the effect of surface temperature mismatch on measurements of skin friction using a plug-type skin friction gage mounted on the side wall of a supersonic wind tunnel. The freestream Mach number was 2.4 and Reynolds number per meter was $5.25 {\times}10^7$ with total pressure of 50 psi and total temperature of 275K. Temperature mismatch between the gage surface and surrounding wall surface was generated by hot water injection using the active temperature control system. Results of the tests showed that the temperature mismatch made sizable effects on the measurements of skin friction.

  • PDF

Nonlinear thermal displacements of laminated composite beams

  • Akbas, Seref D.
    • Coupled systems mechanics
    • /
    • v.7 no.6
    • /
    • pp.691-705
    • /
    • 2018
  • In this paper, nonlinear displacements of laminated composite beams are investigated under non-uniform temperature rising with temperature dependent physical properties. Total Lagrangian approach is used in conjunction with the Timoshenko beam theory for nonlinear kinematic model. Material properties of the laminated composite beam are temperature dependent. In the solution of the nonlinear problem, incremental displacement-based finite element method is used with Newton-Raphson iteration method. The distinctive feature of this study is nonlinear thermal analysis of Timoshenko Laminated beams full geometric non-linearity and by using finite element method. In this study, the differences between temperature dependent and independent physical properties are investigated for laminated composite beams for nonlinear case. Effects of fiber orientation angles, the stacking sequence of laminates and temperature on the nonlinear displacements are examined and discussed in detail.

Post-buckling analysis of Timoshenko beams with temperature-dependent physical properties under uniform thermal loading

  • Akbas, Seref Doguscan;Kocaturk, Turgut
    • Structural Engineering and Mechanics
    • /
    • v.44 no.1
    • /
    • pp.109-125
    • /
    • 2012
  • Post-buckling behavior of Timoshenko beams subjected to uniform temperature rising with temperature dependent physical properties are studied in this paper by using the total Lagrangian Timoshenko beam element approximation. The beam is clamped at both ends. In the case of beams with immovable ends, temperature rise causes compressible forces end therefore buckling and post-buckling phenomena occurs. It is known that post-buckling problems are geometrically nonlinear problems. Also, the material properties (Young's modulus, coefficient of thermal expansion, yield stress) are temperature dependent: That is the coefficients of the governing equations are not constant in this study. This situation suggests the physical nonlinearity of the problem. Hence, the considered problem is both geometrically and physically nonlinear. The considered highly non-linear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The beams considered in numerical examples are made of Austenitic Stainless Steel (316). The convergence studies are made. In this study, the difference between temperature dependent and independent physical properties are investigated in detail in post-buckling case. The relationships between deflections, thermal post-buckling configuration, critical buckling temperature, maximum stresses of the beams and temperature rising are illustrated in detail in post-buckling case.

The Effects of Temperature Cycling on the Production of Aflatoxin by Aspergillus parasiticus R-716 (Aspergillus parasiticus R-716의 aflatoxin생합성에 미치는 temperature cycling의 영향)

  • 정영철;성낙계;이용욱;정덕화
    • Journal of Food Hygiene and Safety
    • /
    • v.1 no.2
    • /
    • pp.157-162
    • /
    • 1986
  • ABSTRACT-This study was designed to observe the effects of temperature cycling on the aflatoxin production by Aspergillus parasiticus R-716 in modified SLS medium. Temperature cycling resulted in total aflatoxin production more than did constant incubation at either $28^{\circ}C$, which was considered to be optimum for aflatoxin production, or $17.5^{\circ}C$, which had the same total thermal input as the temperature cycling. The aflatoxin biosynthesis correlated with the color intensity of media, but was controversal with lipid biosynthesis, and aflatoxin concentration is not related to changes in the fatty acid compositions of used strain.strain.

  • PDF

The Study on the Sweating Responses of Adult Female according to Garment types (의복형태에 따른 성인여성의 발한반응에 관한 연구)

  • Yeom Hee Gyong;Choi Jeong Wha
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.16 no.4 s.44
    • /
    • pp.405-416
    • /
    • 1992
  • This study was performed to investigate correlation between total body weight loss and local sweat rate and to find out any possible method that can estimate total body weight loss judging from local sweat rate. Twelve adult females were kept at 44 $\pm1^{\circ}C$, 50 ${\pm}5\%$ R.H. (1) Physiological responses such as total body weight loss, local sweat rate, rectal temperature, skin temperature, blood pressure and pulse, (2) micro climate inside garment and (3) subjective sensation were examined. Two types of garment such as long-sleeves with long pants (Type I) and half·sleeves with short pants (Type II) were used to observe the effect of garment types on sweating response. Both clothing weight was equal (132$\pm$3 g/$m^{2}$). The results were as follows: 1. Regardless of the different types, total body weight loss was more interrelated with the sweat rate on forehead than any other parts of the body. Except the forehead, different parts of body with different types of garment influenced on body weight loss quite differently. 2. Total body weight loss was more interrelated with the weight gain of garment than the local sweat rate. 3. Under the environment of 44$\pm1^{\circ}C,\;50{\pm}5\%$R.H., body weight loss during 1 hour of subject clothed and silted was 275.2 g/hr and weight loss per body surface area was 178.9 g/$m^{2}/hr$ Garment types have no influences on total body weight loss. 4. Local sweat rate (mg/7.07 $cm^{2}/hr$) was 208.0,191.0, 133.0, 115.0,81 0, 75.1 and 66.3 on scruff, breast, forehead, forearm, thigh, upper arm, leg respectively No evidence has been found that garment types influenced on local sweat rate (p<0.1). 5. No interrelationships between rectal temperature and total body weight loss, local skin temperature and total body weight loss, and local skin temperature and local sweat rate were found. From this study, some possible method that we can estimate total body' weight loss judging from weight loss of garment. But considering the fact that clothing design factor, the physical characteristics of fabric and environmental factor such as humidity and wind velocity should be concerned in weight loss of garment, it should be studied further whether the total body weight loss can be estimated properly from the weight loss of garment. This experiment suggest that different parts of body with different types of garment can influence on body weight loss quite differently. Therefore, in order to get more precise results, more studies under the diversity of garment types should be done in the near future.

  • PDF

The Comparative Study of the Effects of Fructificatio Inonoti Obliqui Aqueous Extract according to the Extraction Temperature(II) -Anti-oxidativy Activity, anti inflammatory effect and cancer cell multiplication inhibition effect- (차가버섯 물 추출물의 추출온도에 따른 효능 비교 연구(II) -항산화 효능, 소염 및 항암 효과 연구-)

  • Park, Kyu-Cheon;Han, Hyo-Sang;Lee, Young-Jong
    • The Korea Journal of Herbology
    • /
    • v.22 no.4
    • /
    • pp.187-199
    • /
    • 2007
  • Objectives : The present study purposed to compare the antioxidant effect, anti inflammatory effect and cancer cell multiplication inhibition effect of Fructificatio Inonoti Obliqui aqueous extract according to extraction temperature. Methods : We medicated animal models, which had experimental oxidation, with Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low temperature leachate, and performed hematological analysis and blood chemical analysis with measuring SOD, GSH, catalase, NO and MDA content in the liver. In addition, we made comparative observation of anti inflammatory effect and anti-cancer effect. Results : Compared to the control group, both the group medicated with Fructificatio Inonoti Obliqui total extract and with $50^{\circ}C$ low-temperature leachate were found to decrease the number of thrombocytes in blood plasma and NO content while to increase SOD activity and catalase activity significantly. Both groups also showed anti-inflammatory effect against THP-1 cells and a multiplication inhibition effect against liver cancer cells and stomach cancer cells significantly. Conclusions : Both Fructificatio Inonoti Obliqui total extract and Fructificatio Inonoti Obliqui $50^{\circ}C$ low-temperature leachate have significant antioxidant effect, anti inflammatory effect and anti cancer effect.

  • PDF

A Study on the Microbiological Quality of Drinking Water and Changes During Storage

  • Kim, Jong-Gyu
    • Journal of Environmental Health Sciences
    • /
    • v.33 no.6
    • /
    • pp.517-521
    • /
    • 2007
  • To assess possible risks from the consumption of drinking water from various sources, a survey of the microbiological quality of tap water, commercial bottled drinking water which is exploited from natural mineral water, and natural spring water was conducted. A total of 4 different brands of commercial bottled drinking water, and 4 types of spring water from different sources, and tap water from 4 private houses were tested for four index microorganisms, and the microbial quality changes of the water during the storage at room temperature or refrigerated temperature for 7 days. Aerobic plate counts of all of the initial water samples were still within 100 CFU/ml (drinking water standard of Korea). Total coliforms, fecal coliforms, and E. coli were not detected in all of the water samples at initial. However, aerobic plate counts of three types of spring water and three types of bottled drinking water stored at room temperature showed higher levels than the standards in 5 days. Total coliforms were detected in three types of spring water after one day's storage at room temperature, and in one type of bottled drinking water after 5 days' storage. These results indicate that some of the spring water surveyed are not safe to drink, and the spring water and bottled drinking water after opening the lid should not be stored at room temperature, if they are used for drinking.

Polyphenol Contents of Rumex crispus Root Extract with Hot Water and its Antioxidative Effect (소리쟁이 뿌리 열수 추출물의 폴리페놀 함량 및 추출물의 항산화 효과)

  • Yun, Young-Sim;Jeong, Kap-Seop
    • Journal of Environmental Science International
    • /
    • v.21 no.10
    • /
    • pp.1265-1274
    • /
    • 2012
  • This study was conducted to investigate the extraction characteristics including total polyphenol compound content (TPC) and the antioxidative effect of Rumex crispus root extract on commercial corn oil. Extraction yield was increased with extraction temperature but decreased with extraction ratio. No significant differences in aromatics content were found among the extracts prepared with various extraction conditions; extraction ratio, extraction temperature, extraction pH and composition of extractant. Total flavonoid content of the extract was increased with extraction temperature and extraction pH, and highest value of it was found when extractant composition of ethanol in water was 75%. Total polyphenol compound content (TPC) of the extract with 10 fold extraction ratio showed the highest value, but no significant difference in TPC was found with extraction temperature. Reducing power and DPPH (${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging ability (RSA) of the extract in spectrophotometric absorbance were decreased with extraction ratio but increased with extraction temperature and showed 63.1%~98.4% and 67.6%~86.7% of those of ascorbic acid in reducing power and DPPH RSA, respectively. The antioxidative effects of the extract on corn oil were 84.8~93.0% of that of commercial butylated hydroxytoluene, the antioxidant index value was highest when the ethanol composition to water in extractant was equal ratio.

Core Temperature Evaluation in Different Body Parts in Patients Undergoing Laparoscope Surgery under Total Intravenous Anesthesia (전정맥 전신마취하(下) 복강경 수술환자의 부위별 심부체온의 변화 평가)

  • Hahm, Tae Soo;Kim, Won Ho;Kim, Nam Cho;Yoo, Je Bog
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.22 no.4
    • /
    • pp.379-386
    • /
    • 2015
  • Purpose: The trend of body temperature change during laparoscopic surgery and the most adequate site for monitoring temperature measurements have not been investigated thoroughly. In this study body temperature change during laparoscopic surgery was measured and measurements of the tympanic, esophageal, and nasopharyngeal core temperatures in surgical patients with total intravenous anesthesia were compared. Methods: From February to October 2013, 28 laparoscopic surgical patients were recruited from a tertiary hospital in Seoul. The patients' core temperature was measured 12 times at ten minute intervals from ten minutes after the beginning of endotracheal intubation. Results: Repeated measure of core temperatures indicated a significant difference according to body part (p=.033), time of measure (p<.001) and the reciprocal interaction between body part and time of measure (p<.027). The core temperatures were highest at tympany location, lowest at nasopharynx. The amount of temperature change was least for the esophagus ($36.10{\sim}36.33^{\circ}C$), followed by nasopharynx and tympany. Conclusion: The esophageal core temperature showed the highest stability followed by nasopharyngeal and tympanic temperature. Therefore, close observations are required between 10~20minutes after the beginning of the operation.