• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1269-1286
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• 2017

This paper presents a newly developed resonance self-shielding method based on Tone's method in $APOLLO3^{(R)}$ for fast and thermal reactor calculations. The new method is based on simplified models, the narrow resonance approximation for the slowing down source and Tone's approximation for group collision probability matrix. It utilizes mathematical probability tables as quadrature formulas in calculating effective cross-sections. Numerical results for the ZPPR drawer calculations in 1,968 groups show that, in the case of the double-column fuel drawer, Tone's method gives equivalent precision to the subgroup method while markedly reducing the total number of collision probability matrix calculations and hence the central processing unit time. In the case of a single-column fuel drawer with the presence of a uranium metal material, Tone's method obtains less precise results than those of the subgroup method due to less precise heterogeneous-homogeneous equivalence. The same options are also applied to PWR UOX, MOX, and Gd cells using the SHEM 361-group library, with the objective of analyzing whether this energy mesh might be suitable for the application of this methodology to thermal systems. The numerical results show that comparable precision is reached with both Tone's and the subgroup methods, with the satisfactory representation of intrapellet spatial effects.

• Earthquakes and Structures
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• v.17 no.5
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• pp.435-445
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• 2019

The collapses of curved bridges are mainly caused by the damaged columns, subjected to the combined loadings of axial load, shear force, flexural moment and torsional moment, under earthquakes. However, these combined loadings have not been fully investigated. This paper firstly investigated the mechanical characteristics of the bending-torsion coupling effects, based on the seismic response spectrum analysis of 24 curved bridge models. And then 9 reinforced concrete (RC) and circular column specimens were tested, by changing the bending-tortion ratio (M/T), axial compression ratio, longitudinal reinforcement ratio and spiral reinforcement ratio, respectively. The results show that the bending-torsion coupling effects of piers are more significant, along with the decrease of girder curvature and the increase of pier height. The M/T ratio ranges from 6 to 15 for common cases, and influences the crack distribution, plastic zone and hysteretic curve of piers. And these seismic characteristics are also influenced by the compression ratio, longitudinal reinforcement ratio and spiral reinforcement ratios of piers.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.34-39
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• 2005

Trichloroethylene (TCE) is an environmental contaminant provoking genetic mutation and damages to liver and central nerve system even at low concentrations. A practical scheme is reported using toluene as a primary substrate to revitalize the biofilter column for an extended period of TCE degradation. The rate of trichloroethylene (TCE) degradation by Pseudomonas putida F1 at $25^{\circ}C$ decreased exponentially with time, without toluene feeding to a biofilter column ($11\;cm\;I.D.{\times}95\;cm$ height). The rate of decrease was 2.5 times faster at a TCE concentration of $970\;{\mu}g/L$ compared to a TCE concentration of $110\;{\mu}g/L$. The TCE itself was not toxic to the cells, but the metabolic intermediates of the TCE degradation were apparently responsible for the decrease in the TCE degradation rate. A short-term (2 h) supply of toluene ($2,200\;{\mu}g/L$) at an empty bed residence time (EBRT) of 6.4 min recovered the relative column activity by $43\%$ when the TCE removal efficiency at the time of toluene feeding was $58\%$. The recovery of the TCE removal efficiency increased at higher incoming toluene concentrations and longer toluene supply durations according to the Monod type of kinetic expressions. A longer duration ($1.4{\sim}2.4$ times) of toluene supply increased the recovery of the TCE removal efficiency by $20\%$ for the same toluene load.

• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.46-50
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• 2019

In this study, the strength stability of an LPG mini tank with a storage capacity of about 250 kg was analyzed by FEM. According to the results of the FEM analysis, it is preferable that the corner radius of the LPG mini tank having a storage capacity of 250 kg is designed to be 175 to 205 mm. Generally, the larger the corner radius of the end plate of the gas storage tank, the higher the safety of the strength, but the volume or capacity of the tank is reduced. Therefore, it is important to derive the optimum design data. Further, in order to securely design the strength of the gas tank, the thickness of the tank is designed to be thick. However, when the thick steel sheet is used, the material and the transportation costs are increased. The result shows that it is preferable to select the optimum thickness of the steel sheet from 4.5 to 5.5 mm. Using the level gauge type of column on the central axis of the gas tank, the safety strength of the LPG tank can be enhanced as much as twice, compared with the tank of the existing level gauge to measure the liquid level by piercing the side wall of the tank.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.70-79
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• 2022

Biodiesel production has attracted attention as a sustainable source of fuel and is a competitive alternate to diesel engines. The glycerol that is produced as a by-product is generally discarded as waste and can be converted to green chemicals such as acetins to increase bio-diesel profitability. Acetins find application in fuel, food, pharmaceutical and leather industries. Batch experiments and analysis have been previously conducted for synthesis of acetins using glycerol esterification reaction aided by sulfated metal oxide catalysts (SO₄^2-/CeO₂-ZrO₂). The aim of this study was to optimize process parameters: effects of mole ratio of reactants (glycerol and acetic acid), catalyst concentration and reaction temperature to maximize glycerol conversion/acetin selectivity. The optimum conditions for this reaction were determined using response surface methodology (RSM) designed as per a five-level-three-factor central composite design (CCD). Statistica software 10 was used to analyze the experimental data obtained. The optimized conditions obtained were molar ratio - 1:12, catalyst concentration - 6 wt.% and temperature -90 ℃. A packed bed reactor was fabricated and column studies were performed using the optimized conditions. The breakthrough curve was analyzed.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.50.2-51
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• 2021

Stars form exclusively in cold and dense molecular clouds. To fully understand star formation processes, it is hence a key to investigate how molecular clouds form out of the surrounding diffuse atomic gas. With an aim of shedding light in the process of the atomic-to-molecular transition in the interstellar medium, we analyze Arecibo HI emission and absorption spectral pairs along with TRAO/PMO 12CO(1-0) emission spectra toward 58 lines of sight probing in and around molecular clouds in the solar neighborhood, i.e., Perseus, Taurus, and California. 12CO(1-0) is detected from 19 out of 58 lines of sight, and we report the physical properties of HI (e.g., central velocity, spin temperature, and column density) in the vicinity of CO. Our preliminary results show that the velocity difference between the cold HI (Cold Neutral Medium or CNM) and CO (median ~ 0.7 km/s) is on average more than a factor of two smaller than the velocity difference between the warm HI (Warm Neutral Medium or WNM) and CO (median ~ 1.7 km/s). In addition, we find that the CNM tends to become colder (median spin temperature ~ 43 K) and abundant (median CNM fraction ~ 0.55) as it gets closer to CO. These results hints at the evolution of the CNM in the vicinity of CO, implying a close association between the CNM and molecular gas. Finally, in order to examine the role of HI in the formation of molecular gas, we compare the observed CNM properties to the theoretical model by Bialy & Sternberg (2016), where the HI column density for the HI-to-H2 transition point is predicted as a function of density, metallicity, and UV radiation field. Our comparison shows that while the model reproduces the observations reasonably well on average, the observed CNM components with high column densities are much denser than the model prediction. Several sources of this discrepancy, e.g., missing physical and chemical ingredients in the model such as the multi-phase ISM, non-equilibrium chemistry, and turbulence, will be discussed.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.190-196
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• 1994

Alkali soluble(AS) fraction, revealed the highest antitumor activity of the alkali extracted fractions of G. lucidum IY 009, was loaded on DEAE cellulose(OH$^{-}$ form) column. AS-1, AS-2, AS-3, AS-4 and AS-5 were obtained by stepwise elution with H$_{2}$O, 0.1 M NaHCO$_{3}$, 0.3 M NaHCO$_{3}$, 0.5 M NaHCO$_{3}$ and 0.5 N NaOH respectively, and their antitumor activities(I.R. %) against the sarcoma 180 were 97.5%, 68.0%, 73.0%, 81.0% and 66.0% respectively. AS-1 observed highest antitumor activity was appeared as single peak on the Sepharose CL-4B column chromatography, and their molecular weight was about 580,000 dalton. The carbohydrate content of AS-1 was 98.9%, their monosaccharide consisted of 67.5% of mannose, 22.5% of xylose, 5.8% of glucose, 1.8% of galactose and 2.0% of ribose. AS-1 was assumed $\alpha $linkaged xylomannan having infrared absorption at 864.3 cm$^{-1}$. The main alditol acetates of AS-1 were identified as 1,5-Di-O-acetyl1-2,3,4-Tri-O-methylxylitol, 1,4,5-Tro-O-acety1-2,3,6-Tri-O-methylmannitol and 1,3,4,5-Tetra-O-acety1-2,6-Di-O-methylmannitol by methylation analysis, and their molar ratio was 1 : 2 : 1. The core portion of AS-1 might be $\alpha $-(1$\longrightarrow $ 4)mannopyranosyl unit branched with side chain, C1 of xylopyranosyl residue linked to C3 of every 3 mannopyranosyl units, and the degree of polymerization of structural unit in AS-1 was about 835.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.495-499
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• 2004

The analyses of peak shapes in chromatography are useful in operating chroma­tographic system. The asymmetry and sharpness of a chromatographic peak are estimated by the reversed-phase adsorption of two standard peptides (angiotensin II bradykinin) on $C_{18}$ In this work, the average particle diameters of $C_{18}$ were 5 and 15 $\mu$m, while the pore sizes were 100 and 300 A. The composition of the mobile phase was $50/50\;vol.\;{\%}$ of a binary mixture of acetonitrile and water with $0.1\%$ TFA, and the particles were packed in a stainless column ($4.6{\times}150$ mm). The third and the fourth central movement were calculated from the chromatographic elution curves by moment analysis. The peak asymmetry was determined by two theoretical calculations: the asymmetry factor by elution peak analysis and skewness with moment analysis. The sharpness was estimated by the fourth central moment. In this work, the most acceptable skewness was calculated when the pore size was 300 A. The large excess was observed on small pore size.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.217-226
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• 2017

This paper summarizes the structural concept and design of the "Nakanoshima Festival Tower West" in Osaka, Japan, which is 200m high and has a super-high damping system. Its superstructure is mainly composed of a central core and outer tube frames. It has a bottom truss structure at the boundary between the low-rise and mid-rise sections of the building, where the column arrangement is changed. Besides, the high-rise section of the building has a neck truss structure. These truss structures smoothly transfer the axial forces of the columns and reduce the flexural deformations induced by horizontal loads. Oil dampers with extremely high damping capacity are installed in the rigid walls named the "Big Wall Frames" of the low-rise section. Moreover, many braces and damping devices are well arranged in the center core of each story. The damping effects of these devices ensure that all structural members are remain within the elastic range and that story drifts are within 1/150 in large earthquakes. This super-high damping structure in the low-rise section is named the "Damping Layer". The whole structural system is named the "Super Damping Structure". The whole structural systems enhance the building's safety, comfort and Business Continuity Planning (BCP) under large earthquakes.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.259-272
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• 1984

Fluid inclusion and stable isotope studies on the Sangdong tungsten skarn have led to a conclusion that the mineralizing fluids might be derived from a magma, which was inferred within 1km below the present Sangdong ore deposit. Mineral assemblages of the skarns appear to have formed under the equilibrium conditions as the fluids flow outward from a central fluid column, in which the quatz-mica occurs dominantly. A characteristic skarn showing mineralogical zonation by repeated over-prints. The quartz-mica zone at the central part of the Sangdong skarns shows the final stage of protracted fluid evolution. Thermodynamic conclusion based on simplified chemical compositions of major components may express quantitatively the conditions of the skarn formation by using diagrams.