• Resources Recycling
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• v.15 no.5 s.73
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• pp.26-32
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• 2006

The waste solution discharged from the LCD manufacturing process contains acids like nitric, acetic and phosphoric acid and metal ions such as Al, Mo and other impurities. It is important to remove impurities less than 1 ppm in phosphoric acid to reuse as an etchant because the residual impurities even in sub-ppm concentration in semiconductor materials play a major role on the electronic properties. In this study, a mixed system of solvent extraction, diffusion dialysis and ion-exchange was developed to commercialize in an efficient system fur recovering the high-purity phosphoric acid. By vacuum evaporation, almost 99% of nitric and acetic acid was removed. And by solvent extraction method with tri-octyl phosphate (TOP) as an extractant, the removal of acetic and nitric acid from the acid mixture was achieved effectively at the ratio A/O=1/3 with 4th stage of extraction stage. About 97.5% of Al and 36.7% of Mo were removed by diffusion dialysis. Essentially almost complete removal of metal ions and purification of high-purity phosphoric acid could be obtained by using ion exchange.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.135-139
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• 1993

Radionuclide cardioangiography has been widely applied and has played major roles in non-invasive assessment of cardiac function. Three techniques, first-pass, gated first and gated equilibrium methods, have commonly been used to evaluate right ventricular ejection fraction which usually abnormal in the patients with cardiopulmonary disease. It has been known that the gated first pass method is the most accurate method among the three techniques in assessment of right ventricular ejection fraction. The radionuclide right ventricular ejection fraction values were determined in 13 normal subjects and in 15 patients with chronic obstructive pulmonary disease by the gated first pass method and compared with those of the first pass method because there ha,j been no published data of right ventricular ejection fraction by the gated first pass method in Korea. The values of right ventricular ejection fraction by the gated first pass method were compared with the detas from the pulmonary function test performed in the patients with chronic obstructive pulmomary disease. The results were as follows: 1) The values of right ventricular ejection fraction by the gated first pass method were $50.1{\pm}6.1%$ in normal subjects and $38.5{\pm}8.5$ in the patients with chronic obstructive pulmonary disease. There was statistically significant difference between the right ventricular ejection fraction of each of the two groups (p < 0.05). 2) The right ventricular ejection fraction by the gated first pass method was not linearly correlated with $FEV_1$, VC, DLCO, and FVC as well as $P_aO_2$ and $P_aCO_2$ of the patients with chronic obstructive pulmonary disease. We concluded that right ventricular ejection fraction by the gated first pass method using radionuclide cardioangiography may be useful in clinical assessment of the right ventricular function.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.121-129
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• 2007

This study was conducted to evaluate the causes and effects of cyanobacterial development and succession in a shallow eutrophic reservoir from March 2003 to February 2004. Phytoplankton succession, sedimentation rate, and sediment composition were analyzed. Algal bioassay also was conducted with the consideration of light, water temperature and nutrients. Cyanobacteria dominated throughout the year, except for spring season (March${\sim}$April) in which diatoms and flagellates dominated. Total cell density increased in July and November when P loading through inflows was high. Oscillatoria spp. and Aphanizomenon sp. were dominant in May and June, respectively, but replaced with Microcystis spp. in July. Thereafter, Microcystis spp. sustained until December, and again shifted to Oscillatoria spp. and Aphanizomenon sp. The dominance of Oscillatoria spp. in May was accompanied with high TN/TP ratio and the increase of water temperature and light intensity. While the dominance of Microcystis spp. was related with relatively low TN/TP ratio, ranging from 46 to 13 (average: 27). The sedimentation rate was highest in March (0.6 m $day^{-1}$) when diatoms dominated. During the period of cyanobacterial dominance, relatively high sedimentation rate was observed in May (0.4 m $day^{-1}$) and October (0.36m $day^{-1}$). C/N ratio of the sediment ranged $6{\sim}8$. Inorganic P concentration in the pore water was low when DO concentration was < 2 mg $O_2$ $L^{-1}$ in the hypolimnion, reflecting the P release from the sediment. Cyanobacterial growth rate depended on phosphorus concentration and water temperature, and high P concentration compensated for the low temperature in the growth rate. Our results suggest that the potential of cyanobacterial development and substantiality in eutrophic reservoirs be high throughout the year, as being supplied with enough P, and emphasize the consideration of sediment man. agement for the water quality improvement and algal bloom control.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.539-546
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• 2009

The effect of hemorrhage on the electroencephalogram(EEG) was investigated in fifteen mixed-breed dogs anesthetized with ketamine, propofol and isoflurane. Animals were randomly allocated to three groups (n = 5) by anesthetic agents; group 1 (ketamine 5 mg/kg, IV), group 2 (propofol $156\;{\mu}g$/kg/min, IV) and group 3 (isoflurane 2.0% end-tidal concentration). Medetomidine ($40\;{\mu}g$/kg, IM) was used in all dogs as a preanesthetic agent. Recording electrode for EEG was positioned at CZ. EEG, heart rate, systolic/diastolic blood pressure, $pCO_2$, $pO_2$ and blood pH were measured before anesthesia, after anesthesia and after every bleedings. Three bleedings were accomplished by drawing blood through the femoral artery catheter at a rate of 7 ml/kg (10% of total blood volume) for 10 minutes. In the course of hemorrhage, a systolic/diastolic pressure continuously decreased in all groups. The $pCO_2$ values and heart rates were increased in all groups. The $pO_2$ values were most significantly increased in group 1 compared with those in other groups. The pH values were not significantly changed. On statistical analysis of EEG, there was no significant changes in group 1 and 3. But in group 2, band 3, 4 and 7 were significantly altered after 2nd and 3rd bleeding. Power alterations of band 3, 4 and 7 were thought to be related with hemorrhage over 20% of total blood volume in group 2. In conclusion, the regulation of infusion rate would be considered when a dog, anesthetized with propofol, bleed over 20% of total blood volume.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.724-731
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• 2012

This study was designed to elucidate whether combination with Korean red ginseng and Morus alba L. (MPM), traditional treatment for diabetes, ameliorates on high fructose-induced steatohepatitis and vascular inflammation. Animals were divided into four groups; Control receiving tap water, fructose-fed, rosiglitazone-treated fructose-fed rats, and MPM-treated fructose-fed rats both receiving supplemented with 60% fructose (n=10). The MPM or rosiglitazone groups initially received a high-fructose diet alone for 8 weeks, with supplementation with MPM or rosiglitazone, peroxisome proliferators-activated receptor gamma ($PPAR{\gamma}$) agonist, occurring during the final 6 weeks. Treatment with MPM significantly prevented the increase in c-reactive protein (CRP) levels in the high fructose group. MPM suppressed high fructose diet-induced vascular inflammation marker expression such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. MPM also reduced intima/media thickness of thoracic aorta. Histologic observation and oil red O staining demonstrated hepatic tissue damage and lipid accumulation were severe in high fructose group. Treatment with MPM ameliorated hepatic tissue morphology with minimized steatosis. In addition, MPM attenuated hepatitis by inhibition of monocyte chemoattractant protein-1 (MCP-1) expression. MPM-fed group showed lower serum GOT and GPT levels comparing with high fructose group. MPM and rosiglitazone (positive control) significantly decreased the size of epididymal adipocytes. Taken together, the administration of MPM inhibited high fructose-induced steatohepatitis and vascular inflammation. These results suggested that MPM is useful in the prevention or treatment of metabolic syndrome-related disorders such as fatty acid metabolism and vascular homeostasis.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.35-41
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• 2004

The yeongok stream originates at the natural park, Mt. O-dae and flows to the East Sea of korea, normally maintaining I or II grade of water quality and its average water flux is 352,100 ㎥/d. However, the typhoon 'Rusa', which occured on 31 August 2002, changed its watercourse and configuration, and the ecosystem was deeply damaged. Moreover, the hydrological characteristics were once more transformed, and the ecosystem was secondarily damaged during repair-work of destroyed bridges and elevations. After the flood disaster, the species diversity diminished 17% for attached diatom and 44% for aquatic animals. However, the earth and sand, dug from river bed during intensive repair-work throughout the entire stream, made diversity drop to 32% for the diatom and the aquatic animals were wiped out. Especially, fishes were totally destroyed except for some species such as Moroco oxycephalus in the upper stream. The yeongok stream has little contamination source and short water residence time due to the short length and rapid slope, and consequently a temporary deterioration of water quality caused by repair-work may be rapidly recovered, but it needs a long time to restore the damaged ecosystem.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.529-533
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• 2012

In this study, we compare various physicochemical properties of solvent extracted coals obtained at both mild and high temperature conditions. In order to characterize the extraction behavior, experiments were performed using a sub-bituminous coal (Kideco) and a polar solvent (N-methyl-2-pyrrolidinone, NMP), where the extraction temperature and the effect of solvent recycling were evaluated. As the extraction temperature increased up to $350^{\circ}C$, an extraction yield and a calorific value of the extracted coal increased, while an ash content of the extracted coal decreased. FT-IR results revealed that the surface of the coal extracted at $350^{\circ}C$ was found to contain more amide, aromatic ester, and aliphatic ether groups than that at the lower temperatures. The result of MALDI-TOF/MS analysis confirmed that the smaller molecules with 300~500 m/z were extracted at a mild condition, while the bigger molecules in the range of 500~1500 m/z were extracted at the high temperature.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.901-910
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• 2003

Using the G-, C-, and NOR-banding techniques, a karyotyping for Korean Native Pig was performed. Blood samples were collected from 50 male Korean Native Pigs that had been bred at the National Livestock Research Institute and then blood cells were prepared from in vitro cultures followed by karyotyping; G-, C-, and NOR-banding patterns of metaphase chromosomes were analyzed. The karyotype of Korean Native Pig is 38, XX or XY which consists of 5 pairs of submetacentric chromosomes(Group I), 2 pairs of acrocentric chromosomes with short p-arm(Group II), 5 pairs of medium metacentric chromosomes(Group III), 6 pairs of acrocentric chromosomes(Group IV) and metacentric X and Y sex chromosomes. On GTG-banding, the Korean Native Pig exhibited a typical and identical banding pattern in each homologous chromosomes. Overall chromosomal morphology and positions of typical landmarks of the Korean Native Pig were virtually identical to those of Committee for the Standardized Karyotype of the Domestic Pig(CSKDP). However, numbers of G-bands of the Korean Native Pig chromosomes were more than those of CSKDP. In chromosomes 1, 3, 5, 6, 7, 8, 13, 14, 15, 16, 17, 18 and X, the Korean Native Pig exhibited more separated bands as compared with CSKDP. In C-banding patterns, although the quantity of heterochromatin was variable in each chromosome, most of the Korean Native Pig chromosomes had heterochromatic C-bands on centromeres. However, the heterochromatic C-band was constantly observed on the whole Y chromosome. In AgNOR staining, the NORs were located at centromeres on the chromosomes 8 and 10. The number of NORs per metaphase ranged from 2 to 4 giving a mean value of 2.13. The number of NORs were distributed on all chromosome pair 10 but not on chromosome 8. The sizes of NORs were also differed between homologous chromosomes 8. Numbers of NORs of Korean Native Pig were significantly higher than those of Yorkshire. The pattern of pig NORs was polymorphic in breeds, individuals and cells, especially on chromosome 8.

• Journal of The Korean Association For Science Education
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• v.4 no.1
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• pp.1-14
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• 1984

The student's attitude toward science is generally influenced by their teachers. Therefore, teachers' positive attitudes toward science and science teaching play an important role to change the student's attitude toward science. The purpose of this survey is to investigate the status on attitudes toward science and science teaching among the secondary school science teachers in Korea. The attitudes were surveyed by the questionnaire which was developed by Sung-Jae Pak. The instrument is designed to use Likert type scale and is composed of two kinds of scale: one is the attitudes toward science scale (the AT scale) and the other is the attitudes toward science teaching scale (the AT Kale), which contains 24 questions respectively. Each of them has 6 sub-level areas. The six areas of attitude toward science are as follow: The goals and values, process and method of science, knowledge and the view of nature, social and cultural aspects, scientist and a career in science, the preferences and willingness. The six areas of attitude toward science teaching are as follow: The goals and values, process and method of science teaching, the content and structure, social and cultural aspects, science educator and a career in science teaching, satisfaction and willingness. From 152 teachers' responses, the tendency of total as well as each area and the contrast of their backgrounds at the level of 5% significance were analyzed by SPSS computer program. Some results and conclusion of the study are as follow: 1. The overall attitude of the measured secondary school science teachers shows a positive trend tendency. Also total positive attitude toward science teaching are slightly higher than that of science, which support the fact that the teachers are not scientists but they are directly involved in teaching of science. 2. The attitudes toward science are moderately correlated to the attitudes toward science teaching (r=0.52). 3. The areas of knowledge, nature-view and tile area of social aspects of science show a very negative tendency. Also the two areas are not correlated to some other areal at the level at 5% significance. 4. Female science teachers exhibit just a little more positive attitudes than those of male teachers in science teaching. 5. The science teachers who wanted to have a profession of scholar or educator exhibit a little more positive attitudes than others in science and total attitudes (AS+AT). 6. The more the science teachers have "intellectual delights" the more their attitudes toward science and science teaching are positive. 7. At the level of 5% significance, there are differences which college they graduated from, but there are no differences in multiple comparison at 10% level. 8. The differences in their background dose not appear in such as age; teaching career; academic career; deny the superstition; their onlook for the scientist or educator when they were freshmen; major the basic science; opinions about the U.F.O. and the origin of life. 9. The responses of certain individual statement are quite different from the overall tendencies, which strongly suggest the de1ailed analysis and deeper study. For the continuing study, it is recommendable to revile the measuring tools with the theoretical study for the better validity and reliability, and investigate the status of the attitudes toward science and science teaching among the science teachers with sufficient samples.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.213-222
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• 2010

In this study, chemical compositions - holocellulose, lignin and monomeric sugars - were characterized with two poplar wood cell walls, one of which was grown at normal condition (CPW) and the other was genetically modified by antisence suppression of CCoAOMT gene expression (ACPW). Milled wood lignins were isolated from CPW and ACPW and subjected to methoxyl group, DFRC, Py-GC/MS, GPC, $^{13}C$-NMR analysis, respectively. There were few differences in holocellulose contents in both cell walls, which were determined to 81.6% in CPW and to 82.3% in ACPW. However, lignin contents in ACPW was clearly decreased by the suppression of CCoAOMT gene expression. In CPW 21.7% of lignin contents was determined, while lignin contents in ACPW was lowered to 18.3%. The relative poor solubility of ACPW in alkali solution could be attributed to the reduction of lignin content. The glucose contents of CPW and ACPW were measured to 511.0 mg/g and 584.8 mg/g and xylose contents 217.8 mg/g and 187.5 mg/g, respectively, indicating that suppression of CCoAOMT gene expression could be also influenced to the formation of monomeric sugar compositions. In depth investigation for milled wood lignin (MWL) isolated from both samples revealed that the methoxyl contents at ACPW was decreased by 7% in comparison to that of CPW, which were indirectly evidenced by $^{13}C$-NMR spectra and Py-GC/MS. According to the data from Py-GC/MS S/G ratios of lignin in CPW and ACPW were determined to 0.59 and 0.44, respectively. As conclusive remark, the biosynthesis of syringyl unit could be further influenced by antisense suppression of CCoAOMT during phenylpropanoid pathway in the plant cell wall rather than that of guaiacyl unit.