• Title/Summary/Keyword: C rate

Search Result 19,598, Processing Time 0.043 seconds

Optimum Water Potential, Temperature, and Duration for Priming of Rice Seeds

  • Lee, Suk-Soon;Kim, Jae-Hyeun;Hong, Seung-Beom;Kim, Min-Kyeong;Park, Eui-Ho
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.43 no.1
    • /
    • pp.1-5
    • /
    • 1998
  • Experiments were carried out to find out the optimum water potential, temperature, and duration for the priming of rice seeds, Oryza sativa L. (cv. Ilpumbyeo) for better germination at sub-optimal temperatures. Seeds were primed in 0, -0.2, -0.4, -0.6, -0.8, and -1.0 MPa PEG (polyethylene glycol) solutions at $25^{\circ}C$. The optimum water potential for seed priming, the highest water potential at which rice seeds did not germinate, was -0.6 MPa. To find out optimum priming temperature and duration rice seeds were primed in -0.6 MPa PEG solution and 0 MPa (water as a control) for various durations at 15 and $25^{\circ}C$ and the seeds were germinated at 17, 20, and $25^{\circ}C$. Considering germination rate and speed, the optimum priming time in water (0 MPa) was 4 days at 15$^{\circ}C$ and 1 day at $25^{\circ}C$, while 4 days was the optimum priming time in a -0.6 MPa PEG solution, regardless of the priming temperature. Priming reduced the actual time of germination, especially at sub-optimal temperatures. Priming did not affect germination rate in -0.6 MPa PEG solution at 15$^{\circ}C$, but overpriming reduced the final germination rate in water at 15$^{\circ}C$ and in -0.6 PEG solution at $25^{\circ}C$. Total sugars and $\alpha$-amylase activity induced during the seed priming were negatively correlated with the final germination rate and there was no noted relationship with the speed or uniformity of germination.

  • PDF

Effect of Water Temperature on Survival, Growth and Intermolt Period of Tiger Crab, Orithyia sinica (Linnaeus) Larvae (범게 (Orithyia sinica Linnaeus) 유생의 생존, 성장 및 탈피주기에 미치는 수온의 영향)

  • Gu, Ja-Geun;Ji, Jeong-Hun;Kim, Jong-Man;Gang, Ju-Chan
    • Journal of fish pathology
    • /
    • v.17 no.2
    • /
    • pp.139-144
    • /
    • 2004
  • In the present study, the effect of different water temperature (15, 20, 25, $30^\circ{C}$ and ambient) on survival, growth rate and intermolt period of zoeal and megalopal stage of tiger crab, Orithyia sinica were examined. The survival rate of zoeal and megalopal stages of experimental crab was observed high at $20^\circ{C}$ and ambient water temperature. The growth rate of crab larvae showed temperature-dependent increase. Therefore, the maximum growth rate was recorded at $30^\circ{C}$ temperature-regulated group in both zoeal and megalopal stage. However, temperature-dependent decrease in larval stages of crab during intermolt period has been observed in the present investigation.

Optimum germination temperature and seedling root growth characteristics of Camelina (카멜리나 (Camelina sativa Crtz.) 발아 적온 및 발아초기 뿌리생육 특성)

  • Park, Joon Sung;Choi, Young In;Kim, Augustine Yonghwi;Lee, Sang Hyub;Kim, Kyung-Nam;Suh, Mi Chung;Kim, Gi-Jun;Lee, Geung-Joo
    • Korean Journal of Agricultural Science
    • /
    • v.40 no.3
    • /
    • pp.177-182
    • /
    • 2013
  • A genus Camelina has been attracted as a promising oil crop, especially available in drought and marginal conditions. Due to more demands on arable land for bioenergy crops, price of agricultural products has been a challengeable issue. In that respect, development of Camelina crop with higher germination rate and germination energy can be a strategy to secure seedling establishment, nutrient uptake and long vegetative period. In order to be easily available in the field and laboratory conditions, Camelina seed needs to be optimized for its germination temperature. Germination temperature regime was in a range of 8 to $32^{\circ}C$ initially, and consecutively narrowed down to 8 to $20^{\circ}C$. Based on the temperature range, Camelina germinated greater than 96% at $8-16^{\circ}C$ in two weeks after sowing, but germination rate started to decrease at the higher than $24^{\circ}C$ and was significantly low at higher than $32^{\circ}C$. In terms of rapid time to reach the maximum germination rate and greater germination energy, temperature ranged from 12 to $16^{\circ}C$ was found to be desirable for Camelina germination. Although germinationa rate was greater at $16^{\circ}C$, lower temperature close to $12^{\circ}C$ would be favored for the field conditions where greater root growth leading to healthier seedlings and better nutrient or water availability is considerably demanded.

Effects of 37℃ Carbon Dioxide Pneumoperitoneum on Core Body Temperature, Systolic Blood Pressure, Heart Rate and Acid-Base Balance: A Randomized Double-blind Controlled Trial (복강경 수술에서 기복제 이산화탄소의 37℃ 가온이 수술 중 체온, 수축기압 및 심박동수와 산염기 균형에 미치는 영향)

  • Park, Jin il;Yoon, Haesang
    • Journal of Korean Biological Nursing Science
    • /
    • v.19 no.2
    • /
    • pp.76-85
    • /
    • 2017
  • Purpose: The purpose of this study was to compare the effects of $21^{\circ}C\;CO_2$ and $37^{\circ}C\;CO_2$ pneumoperitoneum on body temperature, blood pressure, heart rate, and acid-base balance. Methods: Data were collected at a 1300-bed university hospital in Incheon, from February through September 2012. A total of 74 patients who underwent laparoscopic colectomy under general anesthesia with desflurane were randomly allocated to either a control group or an experimental group. The control group received $21^{\circ}C\;CO_2$ pneumoperitoneum; the experimental group received $37^{\circ}C\;CO_2$ pneumoperitoneum. The pneumoperitoneum of the two groups was under abdominal pressure 15 mmHg. Body temperature, systolic blood pressure, heart rate and acid-base balance were assessed at 30 minutes and 90 minutes after pneumoperitoneum, and again at 30 minutes after arriving at the Post Anesthesia Care Unit. Results: Body temperature in the $37^{\circ}C\;CO_2$ pneumoperitoneum group was significantly higher (F= 9.43, p< .001) compared to the $21^{\circ}C\;CO_2$ group. However, there were no statistically significant differences in systolic blood pressure (p= .895), heart rate (p= .340), pH (p= .231), PaCO2 (p= .490) and HCO3- (p= .768) between the two groups. Conclusion: Pneumoperitoneum of $37^{\circ}C\;CO_2$ is effective for the increase of body temperature compared to pneumoperitonium of $21^{\circ}C\;CO_2$, and it does not result in a decrease of blood pressure, heart rate or acid-base imbalance.

Seedling Production and Rearing of Pale Chup, Zacco platypus (Temminck et Schlegel) (피라미, Zacco platypus (Temminck et Schlegel)의 종묘생산)

  • 남명모;최낙중;김성원;석규진;이종윤
    • Journal of Aquaculture
    • /
    • v.12 no.1
    • /
    • pp.25-30
    • /
    • 1999
  • This study was carried out to produce the seedling of the larvae and juveniles of pale chup, Zacco platypus (Cyprinidae) in terms of artificial hatching, feeding behavior and growth rates. The total lengths of the newly hatched larvae were 7.6~8.2mm (mean: 7.97mm). The hatched larvae rose to the surface 3 days after hatching. The larvae were fed Daphnia, rotifer, Artemia and powdered feed. Hatching experiments were conducted in jar incubators under the different water temperature conditions, $20~32^{\circ}C$. The highest hatching rate was at $26^{\circ}C$ after 47 hours. Jar incubators was the highest hatching rate (89%), and cage and Californian incubators were useful and relatively high hatching rates (>89%). The size of the larvae 50 days after hatching were 30.0mm (25.6~32.0mm). As the water temperatures was increased, the growth rate of the larvae was also increased. Especially, the growth rates were favorable over $26^{\circ}C$, but survival was the worst at $32^{\circ}C$. This species was quick to accept assorted feed after hatching. The assorted feeds for flounder and rockfish better than that of carp in reference to growth rate.

  • PDF

Surface crack growth behaviors of 304 stainless steel at elevated temperatures (304 스테인리스 鋼의 高溫에서의 表面균열 成長特性에 관한 硏究)

  • 서창민;신형섭;권영태
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.11 no.3
    • /
    • pp.355-361
    • /
    • 1987
  • Creep and fatigue tests were carried out on crack growth properties of small surface cracks in 304 stainless steel at 538.deg.C, 593.deg. C and 650.deg. C in air, by using small plate specimens with a small artificial pit. All the data of the crack growth rate per hour obtained in the present tests were correlated with the maximum stress intensity factor, so that the applicability of linear fracture mechanics to the crack growth of surface cracks at elevated temperature was investigated. In the creep test, relatiion of .sigma.$\^$n/.t$\_$f/=C is obtained between failure time and nominal stress at each temperature level, where n has the value of 11-14 depending on the temperature level. In the creep and fatigue crack growth properties of surface cracks at the elevated temperatures, the maximum stress intensity factor, $_{4}$$\_$max/, is some extent applicable parameter to describe the surface crack growth rate under the present experimental conditions. The crack growth rate per hour increases when the holding time decreases, and creep crack growth rate per hour becomes the lowest limit of crack growth rate per hour in this tests.

Thermal Degradation Kinetics of Monosodium Glutamate as Affected by Temperature and pH (온도와 pH에 따른 MSG 열분해의 속도론적 연구)

  • Cha, Bo-Sook;Han, Min-Soo;Kim, Woo-Jung
    • Korean Journal of Food Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.355-359
    • /
    • 1991
  • Effects of temperature and pH on thermal degradation of monosodium glutamate(MSG) were investigated during heating of 2% MSG solution at $100{\sim}200^{\circ}C\;and\;pH\;4{\sim}9$. The results showed that the degradation of MSG was very significantly affected by heating temperature and pH. Three hours of heating at $pH\;4\;and\;120^{\circ}C$ resulted appr. 73% MSG degradation while 3 hours at $100^{\circ}C$ decreased only 12%. The comparison study of initial rate of MSG degradation and degradation rate constants showed the highest degradation rate and rate constant and low values in the range of $pH\;6{\sim}8{\sim}$. The values of activation energy calculated from linear relationship of rate constants and 1/T were 18.3 and 9.2 kcal/mole for pH 4 and 5, respectively.

  • PDF

Influence of Strain Rate on Tensile Properties and Dynamic Strain Aging of an Fe-24.5Mn-4Cr-0.45C Alloy (변형률 속도에 따른 Fe-24.5Mn-4Cr-0.45C 합금의 인장 특성과 동적 변형시효)

  • Lee, Seung-Yong;Hwang, Byoungchul
    • Korean Journal of Materials Research
    • /
    • v.26 no.5
    • /
    • pp.281-286
    • /
    • 2016
  • In the present study, the tensile properties and dynamic strain aging of an Fe-24.5Mn-4Cr-0.45C alloy were investigated in terms of strain rate. During tensile testing at room temperature, all the stress-strain curves exhibited serrated plastic flows related to dynamic strain aging, regardless of the strain rate. Serration appeared right after yield stress at lower strain rates, while it was hardly observed at high strain rates. On the other hand, strain-rate sensitivity, indicating a general relationship between flow stress and strain rate at constant strain and temperature, changed from positive to negative as the strain increased. The negative strain-rate sensitivity can be explained by the Portevin Le Chatelier effect, which is associated with dynamic strain aging and is dependent on the strain rate because it is very likely that the dynamic strain aging phenomenon in high-manganese steels is involved in the interaction between moving dislocations and point-defect complexes.

Infection rates of Enterobius vermicularis and Clonorchis sinensis of primary school children in Hamyang-gun, Gyeongsangnam-do (Province), Korea

  • Kim, Bong-Jin;Yeon, Je-Wook;Ock, Mee-Sun
    • Parasites, Hosts and Diseases
    • /
    • v.39 no.4
    • /
    • pp.323-325
    • /
    • 2001
  • The egg Positive rate of Enterobius vermicularis and Clonorchis sinensis of school children in the rural area was studied in Hamyang-gun, Gyeongsangnam-do in Korea. Cellotape anal swab and formalin ether concentration methods were performed one time to 720 Primary school children. The total egg Positive rate of E. vermicularis was 12.6% in two schools (Baekjeon and Wiseong). In the Baekjeon and Wiseong primary school, the egg Positive rate of E. vermicularis was 4.6% and 13.4%, respectively Pinworm egg Positive rate was 17.6% in the lower grades (1st, 2nd and 3rd), and 7.7% in higher grades (4th, 5th and 6th). The total egg Positive rate of male and female was 12.6% and 12.7%, respectively. The egg Positive rate of C. sinensis of Baekjeon and Wiseong Primary school was 1.5% and 0.46%, respectively The total e99 Positive rate of C. sinesis was 0.56%. This survey showed that continuous education and chemotherapy is necessary to treat and prevent reinfection of E. vermicularis. In the case of C. sinensis, health education for school children is recommended to prevent potential infection of adolescents.

  • PDF

RENAL REGULATION OF UREA EXCRETION DURING UREA INFUSION IN ACUTE HEAT EXPOSED BUFFALOES

  • Chaiyabutr, N.;Buranakarl, C.;Loypetjra, P.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.5 no.1
    • /
    • pp.81-90
    • /
    • 1992
  • Five buffaloes kept in normal ambient temperature ($30^{\circ}C$) showed no significant changes in the heart rate, respiratory rate, packed cell volume, plasma constituents and renal hemodymics during intravenous infusion of urea for 4 h. The rate of urine flow, fractional urea excretion, urinary potassium excretion and osmolar clearance significantly decreased while the renal urea reabsorption markedly increased during urea infusion. The decrease of fractional potassium excretion was concomitant with the reduction of the rate of urine flow and urine pH. In animals exposed to heat ($40^{\circ}C$) the rectal temperature heart rate and respiratory rate significantly increased while no significant changes in GFR and ERPF were observed. An intravenous infusion of urea in heat exposed animals caused the reduction of the rate of urine flow with no changes in renal urea reabsorption, urine pH and fractional electrolyte excretions. During heat exposure, there were marked increases in concentrations of total plasma protein and plasma creatinine whereas plasma inorganic phosphorus concentration significantly decreased. It is concluded that an increase in renal urea reabsorption during urea infusion in buffaloes kept in normal ambient temperature depends on the rate of urine flow which affect by an osmotic diuretic effect of electrolytes. The limitation of renal urea reabsorption in heat stressed animals would be attributed to an increases in either plasma pool size of nitrogenous substance or body metabolism.