• Title/Summary/Keyword: Accumulated temperature

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A Study on the Smoldering Zone Spread of the Heaped Saw-Dust (퇴적 목분의 훈소층 전파에 관한 연구)

  • 정국삼;강민호
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.90-96
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    • 1997
  • This paper was concerned with temperature aspect in the smoldering time of the accumulated each saw-dust sample of larch, oregon, aromatic trees which was formed with heaped cone-shape. The smoldering time and temperature of each sample was measured under the wind velocity of 0.10~0.15 m/s and circumstance relative humidity of 60%. As a result, the very lowest heat beginning temperature was detected in aromatic. The effective smoldering phenomena in the sample were detected when the larch saw-dust of [-20+40mesh] and the aromatic saw-dust of [-40+50mesh, -50+60mesh]. Finally the larger a particle size of saw-dust was the better a smoldering time was short. Also, it showed more increasing temperature above $70^{\circ}C$in the smoldering reaction.

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Isolation of Cold Acclimation-related Genes in Wheat Chromosome Substitution Line 5D

  • Chun, Jong Un;Jeong, In Ho
    • Korean Journal of Breeding Science
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    • v.40 no.3
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    • pp.234-242
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    • 2008
  • To identify low temperature-induced genes of wheat chromosome substitution line 5D, suppression subtractive hybridization (SSH) was performed with mRNAs from leaf samples that treated with low temperature ($4^{\circ}C$). A cDNA library was constructed using mRNA isolated from wheat chromosome substitution line 5D leaves treated with low temperature ($4^{\circ}C$). The nucleotide and deduced amino acid sequences of the putative gene products were compared. wfr-9 and wfr-32 showed identity over 90% related to vernalization gene. Other two genes, wfr-77 and wfr-83 which is related to freezing-resistant gene have also identity over 90%. This result suggest that those genes may be transcribed into antifreeze proteins which are accumulated within leaf apoplasts, when wheat chromosome substitution line 5D is acclimated during low temperature treatment.

Mechanical Properties of Ultrafine Grained 5052 Al Alloy produced by Cryogenic Rolling Process (극저온 압연으로 제조된 5052 Al Alloy의 기계적 성질)

  • Lee Y. B.;Nam W. J.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.08a
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    • pp.233-239
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    • 2004
  • The effect of annealing temperature on microstructures and mechanical properties of the sheets received $88\%$ reduction at cryogenic temperature was investigated for the annealing temperature of $150\~300^{\circ}C$, in comparison with those at room temperature. The presence of equiaxed grains, whose size is about 200nm in a diameter, was observed in 5052 Al alloy deformed $88\%$ and annealed $200^{\circ}C$ for an hour. When compared with the deformation at room temperature, the deformation at cryogenic temperature showed the higher strengths and equivalent elongation after annealing at the annealing temperature below $200^{\circ}C$. However, for annealing above $250^{\circ}C$ materials deformed at cryogenic temperature showed the lower strength than those deformed at room temperature. This behavior might be attributed to the higher rate of recrystallization and growth in materials deformed at cryogenic temperature during annealing, due to the lager density of dislocations accumulated during the deformation.

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Effects of Temperature on the Development of Gypsy moth (Lymantria dispar) (매미나방(Lymantria dispar) 발육에 미치는 온도의 영향)

  • A-Hae Cho;Hyo-Jeong Kim;Jin-Hee Lee;Ji-in Kim
    • Korean journal of applied entomology
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    • v.62 no.4
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    • pp.385-388
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    • 2023
  • Gypsy moth (Lymantria dispar), a polyphagous insect pest belonging to the family Lymantriidae, is widely distributed in Korea, Japan, Siberia, Europe, and North America. They pose a threat to various host plants including pear trees, apple trees, and blueberries. Traditionally considered a forest pest, the increasing incursion of gypsy moths into agricultural land near forested areas has intensified damage to crops lacking effective control methods. This study aimed to investigate the temperature-dependent development of gypsy moths to enhance outbreak prediction and advance technology development. The effects of temperature on development of each life stage were investigated under constant temperature conditions of 18, 21, 24, 27, 30, and 33℃ (14L:10D, RH 60±5%) utilizing egg masses collected in Jeollanam-do Jangheung-gun in 2021. The results revealed that higher temperatures accelerated the development rate of the gypsy moth larvae with optimal development occurring at 30℃. However, the survival rate was lowest at 33℃. At the favorable temperature of 30℃, the total development period was 43.8 days for females and 42.5 days for males. The developmental threshold temperature were 13.1℃ for females and 12.5℃ for males, with effective accumulated temperature of 641.1 DD and 657.8 DD, respectively.

Elevated Temperature Design of KALIMER Reactor Internals Accounting for Creep and Stress-Rupture Effects

  • Koo, Gyeong-Hoi;Bong Yoo
    • Nuclear Engineering and Technology
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    • v.32 no.6
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    • pp.566-594
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    • 2000
  • In most LMFBR(Liquid Metal Fast Breed Reactor) design, the operating temperature is very high and the time-dependent creep and stress-rupture effects become so important in reactor structural design. Therefore, unlike with conventional PWR, the normal operating conditions can be basically dominant design loading because the hold time at elevated temperature condition is so long and enough to result in severe total creep ratcheting strains during total service lifetime. In this paper, elevated temperature design of the conceptually designed baffle annulus regions of KALIMER(Korea Advanced Liquid MEtal Reactor) reactor internal strictures is carried out for normal operating conditions which have the operating temperature 53$0^{\circ}C$ and the total service lifetime of 30 years. For the elevated temperature design of reactor internal structures, the ASME Code Case N-201-4 is used. Using this code, the time-dependent stress limits, the accumulated total inelastic strain during service lifetime, and the creep-fatigue damages are evaluated with the calculation results by the elastic analysis under conservative assumptions. The application procedures of elevated temperature design of the reactor internal structures using ASME Code Case N-201-4 with the elastic analysis method are described step by step in detail. This paper will be useful guide for actual application of elevated temperature design of various reactor types accounting for creep and stress-rupture effects.

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Relationship between Yearly Fruit Growth and Climatic Factors in 'Niitaka' Pear (배 '신고'의 연차간 과실 생장과 기상 요인과의 상관성)

  • Han, Jeom Hwa;Son, In Chang;Choi, In Myeong;Kim, Seung Heui;Cho, Jung Gun;Yun, Seok Kyu;Kim, Ho Cheol;Kim, Tae-Choon
    • Horticultural Science & Technology
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    • v.31 no.1
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    • pp.8-13
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    • 2013
  • This research was conducted to investigate the effect of climatic factors on fruit growth in 'Niitaka' pear (Pyrus pyrifolia). For ten years from 2000 to 2010, average full bloom date was April 19th and standard deviation was 4.2 days. Average fruit diameter 160 days after full bloom (DAFB) was 102.4 mm and standard deviation was 7.5 mm. Variance coefficients among climatic factors were higher in rainfall amount and sunshine hours than temperature. Only sunshine hours of climatic factors accumulated during the 160 DAFB had significant positive relationship ($r=0.68^*$) with fruit diameter 160 DAFB. Between full bloom date and fruit diameter 160 DAFB had no significant relationship. Fruit growth in 2004, as continuous rain fall and short sunshine hours, showed opposite pattern compared to that in 2009. Therefore, fruit growth of 'Niitaka' pear was more influenced by the accumulated sunshine hours than accumulated temperature.

A Yield Estimation Model of Forage Rye Based on Climate Data by Locations in South Korea Using General Linear Model

  • Peng, Jing Lun;Kim, Moon Ju;Kim, Byong Wan;Sung, Kyung Il
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.36 no.3
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    • pp.205-214
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    • 2016
  • The objective of this study was to construct a forage rye (FR) dry matter yield (DMY) estimation model based on climate data by locations in South Korea. The data set (n = 549) during 29 years were used. Six optimal climatic variables were selected through stepwise multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the six climatic variables and cultivated locations as dummy variables was constructed as follows: DMY = 104.166SGD + 1.454AAT + 147.863MTJ + 59.183PAT150 - 4.693SRF + 45.106SRD - 5230.001 + Location, where SGD was spring growing days, AAT was autumnal accumulated temperature, MTJ was mean temperature in January, PAT150 was period to accumulated temperature 150, SRF was spring rainfall, and SRD was spring rainfall days. The model constructed in this research could explain 24.4 % of the variations in DMY of FR. The homoscedasticity and the assumption that the mean of the residuals were equal to zero was satisfied. The goodness-of-fit of the model was proper based on most scatters of the predicted DMY values fell within the 95% confidence interval.

Molecular Cloning of Maltooligosyltrehalose Trehalohydrolase Gene from Nostoc flagelliforme and Trehalose-Related Response to Stresses

  • Wu, Shuangxiu;He, Liang;Shen, Rongrong;Zhang, Xiu;Wang, Quanxi
    • Journal of Microbiology and Biotechnology
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    • v.21 no.8
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    • pp.830-837
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    • 2011
  • A genomic DNA fragment encoding a putative maltooligosyltrehalose trehalohydrolase (NfMTH) for trehalose biosynthesis was cloned by the degenerate primer- PCR from cyanobacterium Nostoc flagelliforme. The ORF of NfMTH is 1,848 bp in length and encodes 615 amino acid residues, constituting a 70 kDa protein. The deduced amino acid sequence of NfMTH contains 4 regions highly conserved for MTHs. By expression of NfMTH in E. coli, the function of this protein was demonstrated, where the recombinant protein catalyzed the hydrolysis of maltooligosyl trehalose to trehalose. The expressions of MTH and maltooligosyltrehalose synthase in the filaments of N. flagelliforme were upregulated significantly under dehydration stress, NaCl stress, and high temperature-drought stress. The accumulations of both trehalose and sucrose in the filaments of N. flagelliforme were also improved significantly under the above stresses. Furthermore, trehalose accumulated in smaller quantities than sucrose did when under NaCl stress, but accumulated in higher quantities than sucrose did when under temperature-drought stress, indicating that both trehalose and sucrose were involved in N. flagelliforme adapted to stresses and different strategies conducted in response to various stress conditions.

Transient Analysis of PT-IGBTs at High Temperature

  • Ryu Sehwan;Lee Hokil;Ahn Hyungkeun;Han Deuk-Young
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.39-43
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    • 2001
  • In this paper, excess minority carrier distribution in drift and buffer layers and accumulated charges for PT IGST have been, for the first time, analytically expressed with different transient times, lifetimes and temperatures. Furthermore those parameters are also expressed with temperature to predict the transient response which are critical to the real operation. Active base region has been chosen to extract the temperature dependency of the device by including the buffer layer which is important but neglected due to the complexity up to now.

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Strength Development of Mock-up Concrete Structure subjected to Extremely Low Temperature Condition Due to Curing Methods (극저온 조건에서의 양생방법 변화에 따른 실구조체 콘크리트의 강도발현 특성)

  • Jung, Eun-Bong;Jung, Sang-Hyeon;Ahn, Sang-Ku;Ko, Gyeong-Taek;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.47-49
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    • 2012
  • Under this study, the characteristics of concrete intensity condition following the curing method under the extremely low temperature environment have been contemplated, and as a result, in the event of insulation + heat cable curing, the intensity and accumulated temperature accomplishment period is required for two times of requiring initial frost damage prevention than the case of heating + heat insulation curing method due to the insufficient calories supplied in general.

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