• Title/Summary/Keyword: H1*-H2* Measure

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Characterization of neutron spectra for NAA irradiation holes in H-LPRR through Monte Carlo simulation

  • Kyung-O Kim;Gyuhong Roh;Byungchul Lee
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4226-4230
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    • 2022
  • The Korea Atomic Energy Research Institute (KAERI) has designed a Hybrid-Low Power Research Reactor (H-LPRR) which can be used for critical assembly and conventional research reactor as well. It is an open tank-in-pool type research reactor (Thermal Power: 50 kWth) of which the most important applications are Neutron Activation Analysis (NAA), Radioisotope (RI) production, education and training. There are eight irradiation holes on the edge of the reactor core: IR (6 holes for RI production) and NA (2 holes for NAA) holes. In order to quantify the elemental concentration in target samples through the Instrumental Neutron Activation Analysis (INAA), it is necessary to measure neutron spectrum parameters such as thermal neutron flux, the deviation from the ideal 1/E epithermal neutron flux distribution (α), and the thermal-to-epithermal neutron flux ratio (f) for the irradiation holes. In this study, the MCNP6.1 code and FORTRAN 90 language are applied to determine the parameters for the two irradiation holes (NA-SW and NA-NW) in H-LPRR, and in particular its α and f parameters are compared to values of other research reactors. The results confirmed that the neutron irradiation holes in H-LPRR are designed to be sufficiently applied to neutron activation analysis, and its performance is comparable to that of foreign research reactors including the TRIGA MARK II.

A Study on Adsorption of Lead(II) in Wastewater Using Natural Kaolinite (천연 고령토의 폐수 중 납 흡착에 관한 연구)

  • 이종은
    • Journal of Environmental Health Sciences
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    • v.21 no.3
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    • pp.77-86
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    • 1995
  • Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

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Effect of Genetic-Environmental Interaction on Quality of Wheat (소맥(小麥) 품질특성(品質特性)의 유전(遺傳) 및 환경적(環境的) 변이(變異))

  • Chang, Hak-Gil;Kim, Chang-Sik;Hah, Duk-Mo;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.18 no.1
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    • pp.31-37
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    • 1986
  • Seven cultivars of hard and soft wheat were evaluated by regression analysis for five bread quality characteristics to determine varietal response to environments. The regression coefficients were used as the measure of adaptability, and determination coefficients were used as the measure of stability by models of Eberhart and Russell. Phenotypic, genotypic and environmental correlation coefficient estimated for 6 characters tested in this experiments. Statistical analyses confirmed the strong influence of environment on five bread quality. A significant positive correlation exists between protein content, sedimentation value, pelshenke value and specific loaf volume. High heritability was found for sedimentation value ($h^2=0.747$), protein content ($h^2=0.557$) and specific loaf volume ($h^2=0.551$).

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Glass Dissolution Rates From MCC-1 and Flow-Through Tests

  • Jeong, Seung-Young
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.257-258
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    • 2004
  • The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

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SYMBOLIC DYNAMICS AND UNIFORM DISTRIBUTION MODULO 2

  • Choe, Geon H.
    • Communications of the Korean Mathematical Society
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    • v.9 no.4
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    • pp.881-889
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    • 1994
  • Let ($X, \Beta, \mu$) be a measure space with the $\sigma$-algebra $\Beta$ and the probability measure $\mu$. Throughouth this article set equalities and inclusions are understood as being so modulo measure zero sets. A transformation T defined on a probability space X is said to be measure preserving if $\mu(T^{-1}E) = \mu(E)$ for $E \in B$. It is said to be ergodic if $\mu(E) = 0$ or i whenever $T^{-1}E = E$ for $E \in B$. Consider the sequence ${x, Tx, T^2x,...}$ for $x \in X$. One may ask the following questions: What is the relative frequency of the points $T^nx$ which visit the set E\ulcorner Birkhoff Ergodic Theorem states that for an ergodic transformation T the time average $lim_{n \to \infty}(1/N)\sum^{N-1}_{n=0}{f(T^nx)}$ equals for almost every x the space average $(1/\mu(X)) \int_X f(x)d\mu(x)$. In the special case when f is the characteristic function $\chi E$ of a set E and T is ergodic we have the following formula for the frequency of visits of T-iterates to E : $$ lim_{N \to \infty} \frac{$\mid${n : T^n x \in E, 0 \leq n $\mid$}{N} = \mu(E) $$ for almost all $x \in X$ where $$\mid$\cdot$\mid$$ denotes cardinality of a set. For the details, see [8], [10].

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3-D Shock Structure of Orion KL Outflow with IGRINS

  • Oh, Heeyoung;Pyo, Tae-Soo;Kaplan, Kyle F.;Koo, Bon-Chul;Yuk, In-Soo;Lee, Jae-Joon;Mace, Gregory N.;Sokal, Kimberly R.;Hwang, Narae;Park, Chan;Park, Byeong-Gon;Jaffe, Daniel T.
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.38.3-38.3
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    • 2018
  • We present the results of high-resolution near-IR spectral mapping toward the Orion KL outflow. In this study, we used the Immersion Grating Infrared Spectrometer (IGRINS) on the 2.7 m Harlan J. Smith Telescope at McDonald Observatory. IGRINS's large wavelength coverage over the H & K bands and high spectral resolving power (R ~ 45,000) allowed us to detect over 35 shock-excited ro-vibrational H2 transitions and to measure directly the gas temperature and velocity of the dense outflows. In our previous study toward the H2 peak 1 region in the Orion KL outflow, we identified 31 outflow fingers from a datacube of the H2 1-0 S(1) $2.122{\mu}m$ line and constructed a three-dimensional map of the fingers. The internal extinction (${\Delta}AV$ > 10 mag) and overall angular spread of the flow argue for an ambient medium with a high density (105 cm-3). In this presentation, we show preliminary results of additional mapping toward a remarkable chain of bows (HH 205 - HH 207) farther from the ejection center, and obtain a more clear view of the shock physics of a single isolated bullet that improves on the knowledge gained from observations of the more complex peak 1 region in our earlier study.

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Equivalence Ratio Measurements in Gas Spray Using Laser Raman Scattering (Laser Raman Scattering을 이용한 가스 분무내 당량비 계측에 관한 연구)

  • Jin, S.H.;Park, K.S.;Song, J.I.;Kim, G.S.
    • Journal of ILASS-Korea
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    • v.2 no.4
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    • pp.7-14
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    • 1997
  • Laser Raman scattering method has been applied to measure equivalence ratio of methane/air mixture in injected spray. We used high power KrF excimer laser$(\lambda=248nm)$ and a high gain ICCD camera to capture low intensity signal. Raman shifts and Raman scattering cross -sections of $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4\;and\;C_3H_8$ are measured precisely. Our results show an excellent agreement with those of other groups. Mole fraction measurement of $O_2\;and\;N_2$ from air shows that $O_2:N_2=0.206:0.794$. We used gas injector which was operated at 1 bar. Methane is used as a fuel. Spray region is $10mm\times37mm$ and this region is divided into 80 points. In Raman signals are obtained and ensemble averaged for each point. 3-d and contour plot of distribution of equuivalence ratio is presented. Our measured results show that the equivalence ratio of methane/air mixture in methane-rich region is reasonable. However, more study is necessary for methane-lean region because background noise level is almost same as Raman intensity of methane.

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A Study on the Performance of Thermal Mass Flowmeter (열량형 질량 유량계의 성능 평가)

  • Choi, Y.M.;Park, K.A.;Yoon, B.H.;Jang, S.;Choi, H.M.;Lee, S.H.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.595-600
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    • 2001
  • Thermal mass flow meter(TMF) and thermal mass flow controller(MFC) were used to measure and to control the mass flow rate of gases. TMF and MFC were designed for specified working pressure and gas. For the case of different working pressure and gases, the flow rate measurement accuracy decreased dramatically. In this study, a TMF and MFC was tested with three different gases and pressure range from 0.2 MPa up to 1.0 MPa. Effect of specific heat causes to increase flow measurement error as much as ratio of specific heat compared with reference gas. Changing of pressure causes to increase flow rate measurement error about -0.2% as the working pressure decreased 0.1 MPa. Response time of MFC was below 3.12 s for the case of increasing of flow rate. But the response time was increased up to 6.92 s for the case of decreasing of flow rate. When the solenoid valve was fully closed, a initial delay time of output of MFC was increased up to 1.36 s.

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A Study of the Presence of Carbonic Acid and Other Potentially Hazardous Substances in Cheongsong Mineral Water (청송약수의 탄산과 유해 가능성 물질 존재에 관한 연구)

  • Lee, Sung-Ho
    • The Korean Journal of Food And Nutrition
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    • v.34 no.1
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    • pp.132-136
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    • 2021
  • The purpose of this study is to measure the levels of eluted and dissolved CO2, and CO, volatile organic substances and radiation composition of Cheongsong mineral water which were collected from November 2019 to July 2020 during the autumn, spring, and summer seasons at collection points located in the upper, middle and lower spring waters. Data of the upper, middle and lower spring waters include the following: the amount of eluted water (average value±standard deviation, mL/min) was 30.07±0.52, 15.03±0.16, 23.73±0.42, and the amount of CO2 gas was 1,000 ppm or more. In addition, there was no detection of CO or total volatile organic substances (TVOC) and the radiation dose was 0.08 to 0.13. μSv/h. A blank test value of 0.08 to 0.10 μSv/h, when compared with the median value, showed a high value of 0.02 μSv/h, and the uranium test results provided by the Cheongsong-gun Office were 0.0118 mg/L (date 2019.06.18) and 0.0091 mg/L (date 2020.06.04.) respectively, which was less than the permission limit of 0.03 mg/L. However, it is believed that further research using more precise devices is needed in order to guarantee the safety and health of the water.

A Study on the Development of Ready-to-wear Garment Size for their Early 20's by Body type and Basic Blocks for Women's Dress (20대 전반 여성의 체형별 기성복 치수설정과 원형개발에 관한 연구)

  • 이형숙;임영자
    • Journal of the Korean Society of Costume
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    • v.50 no.3
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    • pp.87-104
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    • 2000
  • The women's apparel sizing system, currently used in the Korean industry, does not reflect measurement differences associated with varying body types and age. Forty five body meaqsurements were taken on 560 subjects, whoes eages ranged from 18-24. STatistical analysis of the data was coducted by using frequences, crosstables, correlation, oneway ANOVA, Regressio analysis. The results of this study were as follow. 1. Average height of women in their early 20's is 160cm, average bust girth 82cm, average hip girth 90cm and average drop 809. The correlation between height and grth items were low and the correlation of length items in the superior and inferior body were shown to bo high respectively. 2. The average Rhrer index is 1.28 and they ussually seem to be in the thin and standard body group. 3. body types were divided by differences between hip and bust sizes. N type(medium hip), A type (large hip), H type(small hip). A classification by body type showed that N type made up 58% while a type made up 24%. 4. The garment sizes for women in their early 20's were developed. 5. The new basic blocks and garment sizes for women in their early 20's were developed as follows : Bust girth (1/2) = 76N, 76A, 79A type($\frac{1}{2}$B+ 4cm) 79N type($\frac{1}{2}$B+ 3.5cm) 82N, 85N type ($\frac{1}{2}$B +3cm) Hip girth($\frac{1}{2}$) =N type($\frac{1}{2}$H + 2~2.5cm) Atype($\frac{1}{2}$H +1.5~2cm) Waist girth($\frac{1}{2}$)=$\frac{1}{2}$W + 2-3cm Back length =extimated measure -0.5cm Front length=76A, N (Back length + 2.2cm) 79A, N(back length +2.7cm) 82N(Back length +3.2cm) 85N(Back length + 3.7cm) Sleeve length=Sleeve length +3cm.

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