• Analytical Science and Technology
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• v.16 no.2
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• pp.117-124
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• 2003

Oxygen to metal ratio has been measured by wet and dry chemical analysis to study the properties of sintered $UO_2$ pellets and $U_3O_8$ in the lithium reduction process of spent pressurized water reactor fuels. Uranium dioxide pellets simulated for the spent PWR fuels with burnup values of 20,000~60,000 MWd/MtU were prepared by mixing $UO_2$ powder and oxides of fission product elements, pelleting the powder mixture and sintering it at $1,700^{\circ}C$ under a hydrogen atmosphere. For wet chemical analysis, the simulated spent fuels were dissolved with mixed acid (10 M HCl : 8 M $HNO_3$, 2.5 : 1, v/v) using acid digestion bomb technique. The total amount of uranium and fission products added in the simulated spent fuels were measured using inductively coupled plasma atomic emission spectrometry. Weight change of the simulated fuel during its oxydation was measured by thermogravimetry and then the O/M ratio result was compared to that obtained by wet chemical analysis. Influence of $Mo_{0.4}-Ru_{0.4}-Rh_{0.1}-Pd_{0.1}$, quaternary alloy, on the determination of O/M ratio was investigated.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.25-31
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• 2009

An analytical method of $^{99}Tc$ concentration in soil was set up and discussed considering the $^{99}Tc$ concentration in Korean soil measured with its analytical method. A selective TEVA resin was used to separate and purify the $^{99}Tc$ in the soil sample. $^{99m}Tc$ from a commercial $^{99}Mo/^{99m}Tc$ generator was used as a yield tracer for the chemical separation of $^{99}Tc$ and its problem when using $^{99m}Tc$ as a tracer was discussed. The chemical recovery yield of $^{99}Tc$ was above 70%. The optimum conditions of inductively coupled plasma mass spectrometry system(ICP-MS) were set up to determine the $^{99}Tc$ after the separation process. The minimum detectable activity(MDA) was 15 mBq/kg-dry in this analytical procedure. The $^{99}Tc$ concentration in soils of Jeju and Kori were measured in the rage of 33.73-89.16 mBq/kg-dry. Those values were less than those reported in other countries and seemed to be originated from atmospheric fallout.

• Analytical Science and Technology
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• v.13 no.3
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• pp.291-296
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• 2000

The SIMFUEL which composition is similar to PWR nuclear spent fuels was dissolved with a acid digestion bomb. An analytical conditions of ICP-AES for the direct determination of molybdenum in the uranium matrices without separation process were investigated. Based on the effect of uranium on molybdenum intensity. the most optimum wavelengths of molybdenum were found to be 202.030 and 203.844 nm. However, the method of standard additions is applied to overcome the effects of changing background caused by analyzing the sample solutions containing high concentration of uranium and the standard calibration solutions. The relative error of two methods, direct and indirect measurements with cation exchange resin separation procedures, was less than 5%. Therefore it was possible for this procedure to directly measure molybdenum in uranium matrices without separation. And this method was also applied to the determination of several percent of molybdenum in a U-Mo alloy.

• Journal of Astronomy and Space Sciences
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• v.28 no.1
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• pp.17-26
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• 2011

Bow shock, formed by the interaction between the solar wind and a planet, is generated in different patterns depending on the conditions of the planet. In the case of the earth, its own strong magnetic field plays a critical role in determining the position of the bow shock. However, in the case of Mars of which has very a small intrinsic magnetic field, the bow shock is formed by the direct interaction between the solar wind and the Martian ionosphere. It is known that the position of the Martian bow shock is affected by the mass loading-effect by which the supersonic solar wind velocity becomes subsonic as the heavy ions originating from the planet are loaded on the solar wind. We simulated the Martian magnetosphere depending on the changes of the density and velocity of the solar wind by using the three-dimensional magnetohydrodynamic model built by modifying the comet code that includes the mass loading effect. The Martian exosphere model of was employed as the Martian atmosphere model, and only the photoionization by the solar radiation was considered in the ionization process of the neutral atmosphere. In the simulation result under the normal solar wind conditions, the Martian bow shock position in the subsolar point direction was consistent with the result of the previous studies. The three-dimensional simulation results produced by varying the solar wind density and velocity were all included in the range of the Martian bow shock position observed by Mariner 4, Mars 2, 3, 5, and Phobos 2. Additionally, the simulation result also showed that the change of the solar wind density had a greater effect on the Martian bow shock position than the change of the solar wind velocity. Our result may be useful in analyzing the future observation data by Martian probes.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.455-459
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• 2006

The major pathogenesis of acute respiratory distress syndrome (ARDS) is an inflammatory process that results from a diversity of injuries to the body. Due to the various cytokines and vasoactive peptides released from the endothelium, the vascular permeability is increased; the migration of inflammatory cells and the leakage of plasma proteins then occur and edema develops in the alveolus. There is a hypothesis that the impairment of alveolar recruitment in ARDS is caused by a defect of the surfactant system and the resultant increase of alveolar surface tension. This has been studied in pediatric patients in ARDS; after the administration of surfactant, hypoxia, respiratory symptoms and survival chances were improved. To alleviate the major pathogenic mechanism in this disease, that is to say, inflammation of the lung, steroids have been used and studied as another treatment modality for ARDS, and it has been concluded that the administration of low dose methylprednisolone may improve patients' symptoms and survival rates. We report here on a case of a young infant admitted with ARDS, who, after the intratracheal administration of 120 mg/kg surfactant, on $PaO_2/FiO_2$ was elevated. Subsequent low doses of methylprednisolone were given, and the symptoms did not recur, and no fibrotic change was shown during the follow-up period of 2 months.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.559-569
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• 2007

The purposes of this study were to find the main foulant of membrane and the optimal chemical cleaning method for MF(microfiltration) drinking water treatment system using D dam water as water source. The MF pilot plant which can treat maximum $500m^3/d$ consisted of 3 racks and was operated for 10 months under various operation conditions. After 10 months operation, $1^{st}$ and $2^{nd}$ rack of membrane pilot plant system were cleaned chemically and the degree of the restoration of the fouled membrane in terms of the pure water flux was detemnined. Inorganic compounds which contained in chemical cleaning waste was analyzed by Inductively Coupled Plasma (ICP). One membrane module for 3rd rack was disjointed and membrane fouling materials, especially inorganic compounds were investigated by Electron Probe Microanlysis (EPMA) to elucidate the reason of TMP increase. And also, the various chemical reagents (1N HCl or $H_2SO_4$, oxalic acid as acid and 0.3% NaOCl as alkali) were tested by combination of acid and alkali to determine the optimal chemical cleaning method for the MF system using micro-modules manufactured using the disjointed module. It was verified that the inside and outside of membrane module was colorized with black. As a result of the quantitative and semi-qualitative analysis of membrane foulant by ICP, most of inorganic foulant was manganese which is hard to remove by inorganic acid such as HCI. Especially, it was observed by EPMA that Mn was attached more seriously in inside surface of membrane than in outside surface of that. It was supposed that Mn fouling in inside surface of membrane might be caused by the oxidation of soluble manganese (Mn(II)) to insoluble manganese ($MnO_2$) by chlorine containing in backwashing water. The optimal cleaning method for the removal of manganese fouling was consecutive cleaning with the mixture of 1N HCl and 1% of oxalic acid, 0.3% NaOCl, and 1N HCl showing 91% of the restoration of the fouled membrane.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.22-39
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• 2003

Biological activity of phenolic compounds in seeds and leaves of safflower (Carthamu tinctorius L.) were evaluated using several in vitro and in vivo assays. Six phenolic constituents were isolated from the seeds and identified as N-feruloylserotonia, N- (p-coumaroyl)serotonin, matairesinol, 8′-hydroxyarctigenin, acacetin 7-O-$\beta$-D-glucoside (tilianine) and acacetin. Six phenolic compounds exhibited considerable antioxidative activity, and especially two serotonins showed potent DPPH radical scavenging activity and antiperoxidative activity against rat liver microsomal lipid peroxidation induced by the hydroxyl radical generated via a Fenton-type reaction. Additionally, six phenolic compounds possessed comparable cytotoxicity against three cancer cells, Hela cell, MCF-7 and HepG2 cell, and particularly acacetin and its glycosides had the most potent cytotoxicity. Moreover, we found that feeding safflower seeds attenuated bone loss, and lowered levels of plasma and liver lipids in ovariectomized rats. Serotonins, lignans and flavones stimulated proliferation of the osteoblast-like cells in a dose-dependent manner (10$^{-15}$ ~10$^{-6}$ M), as potently as E$_2$ (17$\beta$-estradiol). Particularly, serotonins were mainly responsible for bone-protecting and lipid lowering effects in ovariectomized rats. Meanwhile, eight flavonoids, including a novel quercetin-7-O-(6"-O-acetyl)-$\beta$-D-glucopyranoside and seven kown flavonoids, luteolin quercetin, luteolin 7-O-$\beta$-D-glucopyranoside, luteolin-7-O-(6"-O-acetyl)-$\beta$-D-gluco-pyranoside, quercetin 7-O- -glucopyranoside, acacetin 7-O-$\beta$-D-glucuronide and apigenin-6-C-$\beta$-D-glucopyranosyl-8-C-$\beta$-D-glucopyranoside were first isolated and identified from safflower leaf. Among these flavonoids, luteolin-acetyl-glucoside and $\beta$quercetin- acetyl-glucoside showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin, quercetin and their corresponding glycosides also exhibited strong antioxidative activity, while acacetin glucuronide and apigenin-6, 8-di-C-glucoside were relatively less active. Finally, changes in phenolic compositions were also determined by HPLC in the safflower seed and leaf during growth stages and roasting process to produce standardized supplement powerds. These results suggest that phenolic compounds in the roasted safflower seed and leaf may be useful as potential sources of therapeutic agents against several pathological disorders such as carcinogenesis, atherosclerosis and osteoporosis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.2
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• pp.93-100
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• 2010

The calcium to phosphate ratio (Ca/P) in biphasic calcium phosphates powders using X-ray diffraction analysis (XRD) was characterized. The BCP powders with various stoichiometric Ca/P molar ratio were synthesized with coprecipitation process and calcination. Compositions of the powders with Ca/P molar ratio between 1.5 and 1.67 were subjected to starting Ca/P molar ratio, pH = 10, and thermal treatment up to $900^{\circ}C$. The structural, morphological and chemical characterizations for BCP powders with stoichiometric Ca/P ratio were carried out with scanning electron microscope (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) and a phase quantification was investigated by XRD. The solubility of HAp, $\beta$-TCP, and BCP powders was tested in the phosphate buffer solution (PBS) at $36.5^{\circ}C$ and pH = 7.4.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.197-205
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• 2005

Development of the packaging is one of the critical issues for commercialization of the RF-MEMS devices. RF MEMS package should be designed to have small size, hermetic protection, good RF performance and high reliability. In addition, packaging should be conducted at sufficiently low temperature. In this paper, a low temperature hermetic wafer level packaging scheme for the RF-MEMS devices is presented. For hermetic sealing, Au-Sn eutectic bonding technology at the temperature below $300{\times}C$ is used. Au-Sn multilayer metallization with a square loop of $70{\mu}m$ in width is performed. The electrical feed-through is achieved by the vertical through-hole via filled with electroplated Cu. The size of the MEMS Package is $1mm\times1mm\times700{\mu}m$. By applying $O_2$ plasma ashing and fabrication process optimization, we can achieve the void-free structure within the bonding interface as well as via hole. The shear strength and hermeticity of the package satisfy the requirements of MIL-STD-883F. Any organic gases or contamination are not observed inside the package. The total insertion loss for the packaging is 0.075 dB at 2 GHz. Furthermore, the robustness of the package is demonstrated by observing no performance degradation and physical damage of the package after several reliability tests.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1579-1584
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• 2002

Twelve adult male crossbred (Sahiwal${\times}$Holstein Friesian) cattle were distributed into four groups of three each on body weight basis. Animals were given wheat straw as a basal diet. The animals of group I and II were supplemented with concentrate mixture and animals of group III and IV were supplemented with cold processed urea molasses mineral block (UMMB). Thirty mg monensin/day/animal was supplemented to the animals of group II and 35 ppm monensin were incorporated in the UMMB supplemented to the animals of group IV. Vit.A and D mixture was given to all the animals once a week. Dry matter (DM) intake (kg/d) through wheat straw was 19.0 percent higher in the UMMB (without monensin) supplemented group (group III) than those of the concentrate mixture (without monensin) supplemented group i.e. group I. Total DM intake (kg/d) was lower in the monensin supplemented groups than those of non-supplemented groups though differences were not statistically significant. Digestible dry matter, organic matter (OM), crude protein (CP) and total digestible nutrients (TDN) intake were similar in all the groups. Average block consumption for 45 d period in the group III (0.95 kg/d) and group IV (0.84 kg/d) did not differ significantly. DM digestibility (%) was significantly (p<0.01) higher in the group II (58.9) as compared to the group I (52.7) and group III (54.0) but similar to the group IV (57.2). OM digestibility was also significantly (p<0.05) higher in the group II (63.2) as compared to that of the group I (54.9) but similar to the group III (57.8) and IV (59.2). Ether extract (EE) digestibility was significantly (p<0.01) higher in the group I (76.9) and II (80.3) as compared to the group III (59.87) and IV (55.77). Nitrogen free extract (NFE) digestibility was significantly (p<0.05) higher in the group II (62.38) as compared to that of the other groups. Crude protein (CP) and crude fibre (CF) digestibilities were not affected either due to UMMB or monensin. Nitrogen balance did also not differ significantly among the groups. However, Ca and P balance (g/d) in the group III (3.1, 1.3) and IV (3.0, 1.4) were significantly (p<0.01) higher than those of the group I (0.6, 0.2) and II (0.4, 0.3). Blood glucose (mg/100ml) was significantly (p<0.01) higher in the group II (65.2) and IV (65.2) as compared to the group I (55.2) and group III (53.9). Plasma urea-N level (mg/100 ml) in the group III (19.0) and IV (17.8) were significantly (p<0.01) higher than that of the group I (10.5) and II (12.3). So, monensin supplementation either with cold process UMMB or concentrate mixture did not show any additional effect on feed intake and digestibility but increases blood glucose level in adult cattle.