• Title/Summary/Keyword: irradiation time

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Hot Atom Chemistry of Bromobenzene (브로모벤젠의 Hot Atom Chemistry)

  • Choi, Jae-Ho
    • Journal of the Korean Chemical Society
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    • v.10 no.1
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    • pp.1-3
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    • 1966
  • The organic yields (i.e. fraction of nuclear events resulting in organic compound formation) of the radioative neutron capture reactions of halogens in purified bromobenzene have been determined varying extraction time, at $100^{\circ}C$ for thermal effect, varying irradiation time, varying neutron flux and with additional U. V. irradiation. Among the important results are; (1) The organic yields show no remarkable fluctuations with time following neutron irradiation; (2) The organic yields show no change with thermal energy; (3) The organic yields of degassed samples are same in different length of irradiation time whereas the yields of the samples in open air appear to increase with increasing time of irradiation (4) The organic yields increase remarkably with increased neutron flux; (5) The organic yields show a sharp increase by additional U. V. irradiation after neutron irradiation.

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Quality Characteristics of Pan Bread Depending on the Time of Microwave Irradiation Time (Microwave 조사 시간에 따른 식빵의 품질 특성)

  • Park, Sang-Jun;An, Hye-Lyung;Lee, Kwang-Suck
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.3
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    • pp.423-432
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    • 2010
  • In order to streamline bread making process that is time-consuming in regard to the characteristics of process, this study focused on microwave irradiation to dough and raising its temperature to monitor potential variations of dough properties and bread quality, and also examined optimum irradiation time to deduce effective ways for streamlining bread making process. According to analyze dough properties depending on microwave irradiation time, it was found that microwave heat (MWH) 2 showed the highest specific volume and oven spring of all and the lowest hardness (i.e. the highest softness). Moreover, MWH 2 scored the highest points in overall preference under sensory characteristics. As a result, it found that 80-second heating of 700 g bread dough, when exposed to microwave irradiation, contributed to the highest quality of bread.

Studies on the Radiosensitivity of the Chromosomes in Cultured Human Cells (사람의 배양세포염색체의, 방사선감수성에 관한 연구)

  • 강영선;김영진;이정길
    • The Korean Journal of Zoology
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    • v.10 no.1
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    • pp.17-20
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    • 1967
  • The present experiment was perform to investigate the frequencies of chromosome aberration with special regard to the chromosome groups and the various time intervals after X-irradiation (60 r) in ormal human foetus cells grown in culture. The cytological preparations were prepared at every 5 through 30 hours after X-irradiation by the air-drying method. 1. The frequencies of chormosome aberration are on the whole decreased as tie elapses after irradiation and this is thought to be due to gradual recovery with time . However, a slight increase in frequencies is observed at 25 and 30 hours after irradiation respectively. This shows that the cells at the these periods are more sensitivity to X-irradation , and those cells are thought to be at G$_2$ and late S stage at the time of irradiation respectively, so t is evident that G$_2$ and late S stages a the time of irradiation respectively , so it is evident that G$_2$ and late S stages are more sensitive to X-irradiation than any other stages. 2. The frequencies of chormosome aberration are decreased in descending order of chormosome group number. The differences among these frequencies are highly significant statistically . Therefore it can be concluded that there is a highly significant difference in radiosensitivity among chromosome groups. that is, the chromosomes of the group A are the most radiosensitive , followed by B, C, D ,E and G in descending order.

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Effect of Microwave Irradiation Time on Microwave-Assisted Weak Acid Protein Hydrolysis

  • Kim, Dahee;Joo, Minhee;Lee, Dabin;Nguyen, Huu-Quang;Kim, Jeongkwon
    • Mass Spectrometry Letters
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    • v.10 no.3
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    • pp.79-83
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    • 2019
  • Horse heart myoglobin (MYG) and bovine serum albumin (BSA) were hydrolyzed by microwave-assisted weak-acid hydrolysis for 10, 20, 30, 40, 50, and 60 min using 2% formic acid (FA) at $100^{\circ}C$. Generally, the number of identified peptides increased with increasing irradiation time, indicating that the duration of microwave irradiation is linked to the efficiency of hydrolysis. For MYG, irradiation for 60 min provided the highest number of identified peptides, the greatest sequence coverage values and the highest MASCOT score values among the investigated irradiation times. Irradiation of BSA for 50 min, however, yielded a greater number of peptides than irradiation for 60 min due to the generation of miscleaved peptides after microwave irradiation for 50 min.

Turn-off time improvement by fast neutron irradiation on pnp Si Bipolar Junction Transistor

  • Ahn, Sung Ho;Sun, Gwang Min;Baek, Hani
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.501-506
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    • 2022
  • Long turn-off time limits high frequency operation of Bipolar Junction Transistors (BJTs). Turn-off time decreases with increases in the recombination rate of minority carriers at switching transients. Fast neutron irradiation on a Si BJT incurs lattice damages owing to the displacement of silicon atoms. The lattice damages increase the recombination rate of injected holes with electrons, and decrease the hole lifetime in the base region of pnp Si BJT. Fast neutrons generated from a beryllium target with 30 MeV protons by an MC-50 cyclotron were irradiated onto pnp Si BJTs in experiment. The experimental results show that the turn-off time, including the storage time and fall time, decreases with increases in fast neutron fluence. Additionally, it is confirmed that the base current increases, and the collector current and base-to-collector current amplification ratio decrease due to fast neutron irradiation.

Electrical and Optical Properties in Transparent Conducting Oxides: Effect of Ultra Violet Irradiation

  • So, Byung-Soo;Hwang, Jin-Ha
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.1 s.18
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    • pp.65-69
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    • 2007
  • A design of experiments was applied in order to investigate the effect of processing variables in UV irradiation on the electrical/optical properties in indium-zinc oxide thin films, The processing variables, equivalently input variables are listed as UV irradiation time, oxygen flow rate, and chamber pressure. The statistical significance of Ultra Violet (UV) treatment was confirmed using a paired-t test. The full factorial $2^3$ design was employed to determine significant main and interaction effects in UV irradiation process. The chamber pressure and the interaction between UV irradiation time and $O_2$ flow rate were found to be statistically significant at the significance level of 0.1. Furthermore, the optimized approach was proposed in achieving the improved conductivity after UV irradiation.

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CHARACTERISTICS OF THE PNEUMATIC TRANSFER SYSTEM AND THE IRRADIATION HOLE AT THE HANARO RESEARCH REACTOR

  • Chung, Yong-Sam;Kim, Sun-Ha;Moon, Jong-Hwa;Kim, Hark-Rho;Kim, Young-Jin
    • Nuclear Engineering and Technology
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    • v.38 no.6
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    • pp.585-590
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    • 2006
  • This paper describes the results of an irradiation test and the specifications of the pneumatic transfer system (PTS) in the NAA #3 irradiation hole at the HANARO research reactor, which was reinstalled after some modifications of the operation mode at the end of 2004. The outer and inner diameters of the PE transfer tube are 34.1 and 27.5 mm, respectively. PE rabbit was used for sample irradiation. The $N_2$ gas pressure of the PTS lines was adjusted to 0.75 bar. The average sending time to the reactor was $8.5{\pm}0.3$ s and the average receiving time back to the receiver was $3.2{\pm}0.2$ s. The internal and external temperature of the irradiation tube was measured in a range of 50 to $80^{\circ}C$ for a 40 s to 80 s irradiation time, respectively. The optimum irradiation time was estimated to be less than 80 s. The thermal, epithermal and fast neutron flux at 30 MW thermal power were $1.42{\pm}0.01{\times}10^{14},\;1.51{\pm}0.04{\times}10^{13}$ and $9.48{\pm}0.69{\times}10^{11} n{\cdot}cm^{-2}{\codt}s^{1-}$, respectively. The cadmium ratio was approximately 9.40. The data obtained will be applied to supplement user information and for reactor management.

Weed and Pest Control by Means of Physical Treatments(I) -Effects of infrared irradiation on sandy loam for weed control- (물리적인 방법을 이용한 잡초 및 병해충방제 방법의 개발(I) -적외선 조사에 의한 잡초방제를 위한 사양토의 가열 효과-)

  • 강화석;유창연;신현동;강위수;오재헌
    • Journal of Biosystems Engineering
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    • v.21 no.1
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    • pp.21-33
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    • 1996
  • This study was to obtain basic information needed to develop the effective weed control method for the production of less polluted agricultural products by inducing viability loss of weed seeds in soil with infrared irradiation. Ceramic plates were heated by LPG with the aid of forced air and the infrared produced from plates was used as the heat source for heating soil. The soil heated in this study was sandy loam with four levels of moisture contents (0.5, 5.1, 9.1, 15.0% wb). The temperature distribution was measured at various soil depths when soil was irradiated with infrared for different irradiation time (30, 60, 90 sec). The soil depths with duration time of minimum 3 minutes over $80^circ C$, temperature inducing viability loss of weed seeds, were investigated. When the moisture content of soil was 0.5% and 5.1% wb, the soil depths which can induce viability loss of weed seeds was greatly increased with increasing irradiation time. When 30 seconds of irradiation time was applied on soil with moisture content of 9.1% or 15.0% wb, any depths of soil tested in this study was not reached to the temperature of 8$0^{\circ}C$. Generally, the soil depth being needed for viability loss of weed seeds was decreased with increasing moisture content of soil.

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One-time measurement of irradiation intensity of Solar Simulator using cds photo-sensors (cds 광전소자(光電素子)를 이용한 인공태양(人工太陽) 일사강도(日射强度)의 동시측정(同時測定))

  • Bai, K.;Cho, S.H.;Lee, N.H.;Auh, P.C.M.
    • Solar Energy
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    • v.5 no.2
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    • pp.28-34
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    • 1985
  • There are two kinds of irradiation intensity deviation, depending on time and position, on illuminated plane when thermal performance of solar collector is tested by using solar simulator. In this study we measured only position deviation of irradiation intensity using 45-cds photosensors and data acqusition system and found the point of average value. By this result we can improve the accuracy of irradiation measurement in indoor test of solar collector.

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Liquid Crystal Orientation Mechanism: Competition Between Rubbing and Ion-beam Method

  • Kim, Ji-Ho;Han, Jeong-Min;Shon, Jin-Geun
    • Journal of Electrical Engineering and Technology
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    • v.8 no.6
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    • pp.1457-1461
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    • 2013
  • The effect of liquid crystal (LC) alignment on a homeotropic polyimide (PI) surface induced by ion beam (IB) irradiation and rubbing process was studied. LC alignment was not affected by IB irradiation with an exposure time of 10 s, and an IB irradiation with an exposure time of 60 s more effectively oriented the LCs on the PI layer than the rubbing process. It was assumed that the LC alignment depended on the C-O bonds created from the C=O bonds on the PI surface broken by IB irradiation after an exposure time of 60 s, which resulted in a strong surface energy that transformed the homeotropic LC alignment to homogeneous states.