• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.191-198
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• 2003

The pairwise energy model (PEM) assumes that the cross section for the reaction cross section for the reaction A+BC$\{leftrightarrow}$B+C, where B and C are isotopes of hydrogen, depends on only the pairwise relative energy Es between A and B. Until now, the PEM has been used to interpret theoretically the isotope effect for the reactions such as $O(^3P)+HD,\;Ar^++(H_2,\;D_2,and\;HD)$. In this paper we carry out extensive quasiclassical trajectory calculations for the three possible reactions $Cl+H_2$ and HD and show that the PEM works very well at high energy. In particular we are able to accurately predict the intramolecular isotope effect at high energy for the reaction of Cl+HD using only the cross section data for $Cl+H_2$. To understand that the PEM works so well at high energy, the internal energy distributions for the products are examined. The distributions for three reactions are different at a fixed relative collision energy E but are approximately same at a fixed pairwise energy Es. This suggests that the PEM works very well at high energy. We believe the conclusions reached here will apply to other A+BC systems.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.948-956
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• 2000

The effect of high and low level of feed intakes on nutrient digestibility, nutrient losses through methane, energy and protein utilization by goats fed on alfalfa (Medicago sativa L.) pellets based diets was investigated in this study. Twelve castrated Japanese goats were employed in two subsequent digestion and metabolism trials. The goats were divided into three groups, offered three diets. Diet 1 consisted of 100% alfalfa pellet, Diet 2 was 70% alfalfa pellet and 30% corn, and Diet 3 was 40% alfalfa pellet and 60% corn. The two intake levels were high (1.6 times) and low (0.9 times) the maintenance requirement of total digestible nutrients (TON). Rumen ammonia nitrogen ($NH_3$-N) level of Diet 1 was lower (p<0.001) compared to Diets 2 and 3, but the values were always above the critical level (I50 mg/liter), The pH values of rumen liquor ranged from 6.02 to 7.30. Apparent digestibility of nutrient components did not show differences (p>0.05) between the two intake levels but inclusion of corn significantly altered the nutrient digestibility. Diet 3 had highest (p<0.001) dry matter (DM), organic matter (OM), ether extract (EE) and nitrogen fee extract (NFE) digestibility followed by the Diet 2 and Diet 1. The crude protein (CP) digestibility values among the three diets were in a narrow range (70.1 to 70.8%). Crude fiber (CF) digestibility for Diet 3 was slight higher (p>0.05) than that for other two diets. When alfalfa was replaced by corn, there were highly significant (p<0.001) increases in DM, OM, EE and NFE apparent digestibility and a slight increase in the CF digestibility (p>0.05). There were no differences (p>0.05) in energy losses as methane ($CH_4$) and heat production among the diets but energy loss through urine was higher for the Diet 1. The total energy loss as $CH_4$ and heat production were higher for the high intake level but the energy loss as $CH_4$ per gram DM intake were same (0.305 kcal/g) between the high and low intake level. Retained energy (RE) was higher for Diet 3 and Diet 2. Nitrogen (N) losses through feces and urine were higher (p<0.001) for Diet 1. Consequently, N retention was lower (p>0.05) for Diet 1 and higher in Diets 3 and 2. It is concluded that inclusion of corn with alfalfa increased the metabolizable energy (ME) and RE, and retained N through reducing the energy and N losses. The high level of intake reduced the rate of nutrient losses through feces and urine.

• Environmental Engineering Research
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• v.23 no.1
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• pp.62-69
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• 2018

In the present study, long-term heavy metals (HMs) contaminated soil samples from a well-known Pb/Zn smelting area in the southwest of China were collected, and physicochemical and biological characteristics of these samples were evaluated. Soil samples contained different concentrations of HMs, namely Pb, Zn, Cu, and Cd. Enzyme activity analyses combined with microcalorimetric analysis were used for soil microbial activity evaluation. Results showed that two soil samples, containing almost the highest concentrations of HMs, also shared the greatest microbial activities. Based on correlation coefficient analysis, high microbial activity in heavily HMs contaminated soil might be due to the high contents of soil organic matter and available phosphorus in these samples. High-throughput sequencing technique was used for microbial community structure analysis. High abundance of genera Sphingomonas and Thiobacillus were also observed in these two heavily contaminated soils, suggesting that bacteria belonging to these two genera might be further isolated from these contaminated soils and applied for future studies of HMs remediation. Results of present study would contribute to the evaluation of microbial communities and isolation of microbial resources to remediate HMs pollution.

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.17-23
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• 2012

The installed capacity of wind turbines in Korea are growing and enlarging by the central government's supporting program. But the majority area having the abundant wind energy resources is composed of mountainous and complex district, thus the turbulence intensity of there is so high and belongs to the turbulence characteristic A category of IEC design requirement. This paper presents the effect of the turbulence intensity on the power performance of a wind turbine system. Particularly, the effect of the power curve of the wind turbine system due to the turbulence intensity has analyzed. As a result, the power curve has a high turbulence characteristic shows the lower value than normal one in high wind speed regime and the AEP will be reduced at the relatively high turbulence area.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.49-54
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• 2005

With the recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low power consumption wireless micro sensor nodes have become available. However, energy-efficient routing is one of the most important key technologies in wireless sensor networks as sensor nodes are highly energy-constrained. Therefore, many researchers have proposed routing protocols for sensor networks, especially cluster-based routing protocols, which have many advantages such as reduced control messages, bandwidth re-usability, and improved power control. Some protocols use information on the locations of sensor nodes to construct clusters efficiently. However, it is rare that all sensor nodes know their positions. In this article, we propose another cluster-based routing protocol for sensor networks. This protocol does not use information concerning the locations of sensor nodes, but uses the remaining energy of sensor networks and the desirable number of cluster heads according to the circumstances of the sensor networks. From performance simulation, we found that the proposed protocol shows better performance than the low-energy adaptive clustering hierarchy (LEACH).

• Nano
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• v.13 no.11
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• pp.1850135.1-1850135.8
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• 2018

A one-step high-temperature solvothermal approach to the synthesis of monolayer or bilayer $MoS_2$ anchored onto reduced graphene oxide (RGO) sheet (denoted as $MoS_2/RGO$) is described. It was found that single-layered or double-layered $MoS_2$ were synthesized directly without an extra exfoliation step and well dispersed on the surface of crumpled RGO sheets with random orientation. The prepared $MoS_2/RGO$ composites delivered a high reversible capacity of $900mAhg^{-1}$ after 200 cycles at a current density of $200mAg^{-1}$ as well as good rate capability as anode active material for lithium ion batteries. This one-step high-temperature hydrothermal strategy provides a simple, cost-effective and eco-friendly way to the fabrication of exfoliated $MoS_2$ layers deposited onto RGO sheets.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.244-249
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• 2019

SiO has a high theoretical capacity as a promising anode material candidate for high-energy-density Li-ion batteries. However, its practical application is still not widely used because of the large volume change that occurs during cycling. In this report, an active material containing a mixture of SiO and graphite was used to improve the insufficient energy density of the conventional anode with the support of multidimensional conducting agents. To relieve the isolation of the active materials from volume changes of SiO/graphite electrode, two types of conducting agents, namely, 1-dimensional VGCF and 0-dimensional Super-P, were introduced. The combination of VGCF and Super-P conducting agents efficiently maintained electrical pathways among particles in the electrode during cycling. We found that the electrochemical performances of cycleability and rate capability were greatly improved by employing the conducting agent combinations of VGCF and Super-P compared with the electrode using only single VGCF or single Super-P. We investigated the detailed failure mechanisms by using systematic electrochemical analyses.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.543-558
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• 2023

Currently, Japan is undertaking a nationwide project to measure and map radioactive contamination around Fukushima, as part of the efforts to restore normalcy following the nuclear accident. The Japan Atomic Energy Agency (JAEA) manages the Fukushima Environmental Safety Center, located approximately 20 km north of the Fukushima Daiichi nuclear power plant in Minamisōma City, Fukushima Prefecture. In collaboration with the JAEA, this study involved conducting comparison experiments and analyses with radiation detectors in high radiation environments, a challenging task in Korean environments. Environmental radiation surveys were conducted using three types of detectors: CZT, NaI(Tl), and LaBr₃(Ce), across two contaminated areas. Dose rate values were converted using dose rate conversion factors for each detector type, and dose rate maps were subsequently created and compared. The detectors yielded similar results, demonstrating their feasibility and reliability in high radiation environments. The findings of this study are expected to be a crucial reference for enhancing the verification and supplementation of procedures and methods in future radiation measurements and mobile surveys in high-radiation environments, using these three types of radiation instruments.

• Journal of Nutrition and Health
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• v.27 no.2
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• pp.119-126
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• 1994

The effect of diets(high fat, high fat high energy, pectin, cellulose) on adipocyte of epididymal fat pads were investigated in 70 male rats for 8 weeks. The rats were assigned to a control(C), high fat(HF) and high fat high energy(HFHE) group for 4 wks. During the next 4 wks, reassigned to one of three treatments (high fat, pectin supplemented, cellulose supplemented) in the HF group and one of three treatment (high fat high energy, pectin, cellulose) in the HFHE group. Therefore, the total experimental groups were 7 (C, HF, HF-P, HF-C, HFHE, HFHE-P, HFHE-C). Parameters evaluated and compared for each diet were body weight, total energy intake, feed efficiency ratio and weight changes in epididymal fat pads. The results are summarized as follows ; 1) There was no significant difference in body weight gain among the groups. 2) Total energy intake was higher in the C group than other groups. 3) Feed efficiency ratio (F.E.R) of the HF and HFHE groups were greater than C group(2, 4 weeks). However, there were no significant differences between the HF and HFHE groups. 4) Epididymal fat pads(EFP 100g/B.W) of the FH and HFHE groups were higher than C group (2, 4 weeks). However, there were no significant differences between the HF and HFHE groups. There was no significant difference in weight gain of epididymal fat pads among the groups(8 weeks). 5) Cell number and cell size of epididymal fat pads of the HF and HFHE groups were higher than the C group. The pectin and the cellulose supplementation groups decreased cell number and cell size of epididymal fat pads. Especially, the pectin supplementation group decreased than the cellulose supplementation in HFHE group. Therefore, we can concluded that the HF and the HFHE diet has no effect on the epididymal fat pads.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.387.1-387.1
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• 2016

Transparent materials are necessary for most photoelectric devices, which allow the light generation from electric energy or vice versa. Metal oxides are usual materials for transparent conductors to have high optical transmittance with good electrical properties. Functional designs may apply in various applications, including solar cells, photodetectors, and transparent heaters. Nanoscale structures are effective to drive the incident light into light-absorbing semiconductor layer to improve solar cell performances. Recently, the new metal oxide materials have inaugurated functional device applications. Nickel oxide (NiO) is the strong p-type metal oxide and has been applied for all transparent metal oxide photodetector by combining with n-type ZnO. The abrupt p-NiO/n-ZnO heterojunction device has a high transmittance of 90% for visible light but absorbs almost entire UV wavelength light to show the record fastest photoresponse time of 24 ms. For other applications, NiO has been applied for solar cells and transparent heaters to induce the enhanced performances due to its optical and electrical benefits. We discuss the high possibility of metal oxides for current and future transparent electronic applications.