• Nuclear Engineering and Technology
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• v.12 no.2
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• pp.99-105
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• 1980

The distribution of $^{55}$ Mn and $^{38}$ Cl recoil species following radiative neutron capture in permanganates, chlorates and perchlorates has been investigated by using ion-exchange chromatography method. The whole of the $^{55}$ Mn radioactivity in permanganates appeared in two valence states, the $^{38}$ Cl radioactivity in chlorates in two valence states and also the $^{38}$ Cl radioactivity in perchlorates in three valence states. Recoil energy was calculated. The internal conversion of $^{38}$ Cl isomer transition affects the retention value. The greater the radii of the cation, the higher is the probability of the recoil atom breaking through the secondary cage. In ammonium salt, the ammonium ion behaves as a reducing agent. Crystal structures with their greater free space have shown low retention.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.52-56
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• 1991

Inulin degradation was examined using patially puriiied enzyme mixtures of the Exo-inulinase from a Bacillus spp. and the Endo-inulinase from a Pseudomonas spp.. The highest synergistic xtion of the two cnzymcs was observcd when the Exo- and the Endo-inulinase werc mixed at the ratio of 1 to 13, and the rate of hydrolysis of the above process was enhanced approximately 1.6 times I1ight.1- than that of the reaction catalysed with a single enzyme of the same units. The enzymc mixture showed the maximal activity at pH 6.0 and $55^{\circ}C$, and in the prescncc of 0.5 mM each of $CO^{2+}$ and $Mn^{2+}$. Under the optimal condition described above fructosu was accumulated with the overitll concentration of 84% after 36 hours of the reiiction.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3112-3121
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• 2021

One of the major factors affecting the life span of a Reactor Pressure Vessel (RPV) is the Pressurised Thermal Shock (PTS). PTS is a thermo-mechanical load on the RPV wall due to steep temperature gradients and structural load created by internal pressure of the fluid within the RPV. Safe operating life of a nuclear power plant is ensured by carrying out fracture analysis of the RPV against thermal shock. Carrying out fracture tests on RPV/large scale components is not always feasible. Hence, studies on laboratory level specimens are necessary to validate and supplement the prototype results. This paper aims to study the fracture behaviour of standard Compact Tension [C(T)] specimens, made of RPV steel 20MnMoNi55, subjected to thermal shock through experimental and numerical investigations. Fracture tests have been carried out on the C(T) specimens subjected to thermal transient load and tensile load to quantify the effect of thermal shock. Crack resistance curves are obtained from the fracture tests as per ASTM E1820 and compared with those obtained numerically using XFEM and a good agreement was found. A quantitative study on the crack tip plastic zone, computed using cohesive segment approach, from the numerical analyses justified the experimental crack initiation toughness.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.584-589
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• 2010

Sweet persimmon yield can be limited by soil pH. This study was performed to rapidly determine the optimal level of lime requirement in sweet persimmon field. Soil chemical properties such as Fe, Mn, and Zn were analyzed soil samples of 31 sweet persimmon fields at Gyeongnam Province every two months from April to October in 2008. The available Fe, Mn, and Zn content were significantly high top soil (76.5 mg $kg^{-1}$ for Fe, 46.1 mg $kg^{-1}$ for Mn, and 16.9 mg $kg^{-1}$ for Zn, respectively), and subsoil (55.5 mg $kg^{-1}$ for Fe, 35.9 mg $kg^{-1}$ for Mn, and 12.3 mg $kg^{-1}$ for Zn, respectively) in April. Furthermore, the Mn content was significantly decreased since April compared to other micronutrients. We found a significant negative correlation between soil pH and lime requirement (r=0.881, $p{\leq}0.001$ for top soil, and r=0.855, $p{\leq}0.001$ for subsoil). We suggest that a conversion factor is -171 top soil pH + 1,148 to lime requirement (kg $10a^{-1}$) for top soil, and -190 subsoil pH + 1,247 to lime requirement (kg $10a^{-1}$) for subsoil in sweet persimmon fields. These results supported that the improvement of lime requirement by soil pH value is necessary to rapidly apply to field, and prevent micronutrients over uptake by persimmon plant.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.247-253
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• 2002

Natural manganese ore was selected as main active component for a non-zinc desulfurization sorbent used in the gas clean-up process of the integrated gasification combined cycle (IGCC) because of excellent H$_2$S removal efficiency and economical aspect . In this study, the regeneration characteristics of sorbent after desulfurization reaction were determined in a thermobalance reactor and a fixed bed reactor in the temperature range of 350~55$0^{\circ}C$. The mixed gases of oxygen and nitrogen are used as the regeneration reaction gases for manganese sorbent. According to Mn-S-O phase diagram, the manganese sorbent has a low regeneration efficiency in medium temperature due to formation of MnSO$_4$ and the regeneration temperature must be over 85$0^{\circ}C$. To improve that problem, ammonia and steam was added in regeneration mixed gases. Effect of new regeneration method was determined by XRD and difference of desulfurization through multicycle tests.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.55-55
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• 2009

FGB(Flexible Glasswool Backing) Submerged Arc Welding has been one of the main welding processes for one side butt welding in shipbuilding industries, which can efficiently improve the welding productivity by the addition of a supplementary filler metal into the molten weld pool. As recent ships have become larger in size, the application of high tensile and higher grade of steels has been continuously increased. Single pass FGB SA welding process accompanies such a high heat input when welding thick plates that the mechanical properties of weld metal can be dramatically degraded. This study has been performed in order to obtain high toughness and tensile properties of high heat input FGB SA welds, and to evaluate the effect of alloy elements on their mechanical properties. To complete welding 25mm-thick EH36 grade steel plate by single pass, 1.2mm diameter and 1.0mm long cut wires has been distributed in the groove before welding, and three different test coupons have been made using C-1.5%Mn, C-1.8%Mn-0.5%Mo, and C-1.4%Mn-1.7%Ni cut wires to investigate the influence of nickel(Ni) and molybdenum(Mo) on the mechanical properties of welds. Test results showed that the addition of Ni and Mo effectively promotes the formation of Acicular Ferrite(AF), while significantly reducing the amount of Grain Boundary Ferrite(GBF) in weld metal microstructures, which resulted in a beneficial effect on low temperature impact toughness and strength.

• Korean journal of applied entomology
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• v.28 no.2
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• pp.69-75
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• 1989

The extracellular amylase production by Bacillus thuringiensis subsp. kurstaki HD-l in amylase production media and its characteristics were investigated. The amylase production was highest in the medium composed of 0.2% soluble starch, 1.0% Bacto-peptone, 0.3% beef extract, 0.3% yeast extract, 0.5% NaCl, 0.3% $K_2HPO_4$, 0.1% $KH_2PO_4$, 0.012% $CaCl_2$.$2H_2O$, 0.005% $MnSO_4$.$H_2O$, and 0.03% $MgSO_4$.$7H_2O$. The amylase activity was inhibited by 50mM EDT A. The enzyme was optimally active from pH 6.5 to 7.0 at $55^{\circ}C$, The specific activity of the enzyme in the ethanol precipitate was 2.01 units/mg, and the Km value was approxi-mately 0.8 mg/ml.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.511-521
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• 2000

Investigation was carried out lean burn de-NOx properties of Pt-$TiO_2$ bifunctional catalyst by propylene in order to get the high de-NOx activity and the wide temperature window under coexistence of $SO_2$ and $H_2O$. Only noncatalyst and carrier catalyst themselves had NOx conversion activity at high temperature over $400^{\circ}C$. NOx conversion activity of catalysts exchanged copper ion resulted in Cu-$TiO_2$>Cu-ZSM-5>Cu-$Al_2O_3$>CU-YZ>Cu-AZ. Catalysts impregnated with platinum based on titania gave the results of high NOx conversion activity at low temperature. $250^{\circ}C$. Bifunctional catalysts based on Pt-$TiO_2$ showed high NOx conversion activity both at a low zone of $300^{\circ}C$ and a high zone of $500^{\circ}C$. Pt-$TiO_2$/$Al_2O_3$ catalyst gave the highest NOx conversion activity at a low temperature zone. and Pt-$TiO_2$/$Mn_2O_3$(21) catalyst gave the highest NOx conversion activity at a high temperature zone. Under the coexistence of $SO_2$ and $H_2O$. NOx conversion activities of 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst was high both at a low and high temperature zone, and increased depending on oxygen concentration. 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst showed the best correlation between de-NOx activities and the propyl ere conversion rates to CO on the log function.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1809-1811
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• 2000

High power piezoelectric materials are presently being extensively developed for applications such as ultrasonic motors and piezoelectric transformer In this study, the piezoelectric and dielectric properties of $MnO_2$ doped $0.36Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.25Pb(Ni_{1/3}Nb_{2/3})O_{3}-0.39PbTiO_3$ (hereafter PSNNT), which is the morphotropic phase boundary composition of the PSN-PNN-PT system were investigated. $MnO_2$-addition into the $0.36Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.25Pb(Ni_{1/3}Nb_{2/3})O_{3}-0.39PbTiO_3$ composition increases the piezoelectric coefficient up to $k_{p}{\fallingdotseq}$55.6[%] and $Q_{m}{\fallingdotseq}$252. Moreover, $MnO_2$ addition makes tetragonal phase more stable with respect to rhombohedral phase.

• Korean Journal of Community Nutrition
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• v.17 no.2
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• pp.146-155
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• 2012

This study aimed to measure and evaluate the intakes of four antioxidant trace elements, namely, Zn, Cu, Mn, and Se in 19-29y-old female university students in Korea. Diet data were collected by 3-day dietary records in 644 subjects. The mean age, height, weight and body mass index of the subjects were 20.08 years, 161.77 cm, 54.26 kg and $20.82kg/m^2$, respectively. The mean, median and 25th-75th percentile intakes of Zn, Cu, Mn, and Se in the subjects were 12.83 mg (12.40 mg, 9.59 to 15.34), 1.30 mg (1.27 mg, 1.00 to 1.57), 3.19 mg (3.12 mg, 2.45 to 3.86), and $50.90{\mu}g$ ($50.17{\mu}g$, 37.59 to 64.35), respectively. The proportion of subjects whose Mn intake was adequate or less was 62.89%, and the proportions of subjects whose Zn, Cu and Se intakes were at the estimated average requirements or less were 10.09, 4.97, and 39.60%, respectively. The major food group for dietary intakes of Zn, Cu, Mn, and Se was cereal, providing 8.55 mg (66.60%), 0.78 mg (59.93%), 2.09 mg (65.50%), and $16.83{\mu}g$ (32.43%), respectively. Many female university students were deficient in Mn and Se compared with the dietary reference intakes. Therefore, except for cereal, it is required to consume a diet consisted of various food sources for increasing the intakes of antioxidant trace minerals, especially animal food groups.