• Resources Recycling
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• v.4 no.1
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• pp.38-45
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• 1995

The objective of this study was to investigate the effect of temperature on the formation of CaCO, polymorphs(i.e.,calcite, aragonite, vaterite) and on the crystal shape of CaCO,.The reaction systems were rnvestigated at the temperature range of 2.0%-85.3r, at the fixed cmditions ofconcentration and pressure, 2X10-' M, atomospheric pressure, respectively.The reaction systems studied include a Ca(HCO.,),-Air bubble, O Ca(OH)s-CO,, @ Ca(OH),-H,CO, ,Ca(OH1,-Na>CO,, O Ca(OH),-K,CO,, @ Ca(OH),-(NH,),CO,, D CaC1,-Na,CO,, CaC1,-K3C03, 8 CaC1,-(NH,,),CO,, 0 Ca(N0,X-Na,CO,, 03 Ca(N0,X-QCO,. 0 Ca(NO,),-(NH,XCO,. The results obtained are summarizedas follows:Calcite is formed at the temperature range of 2t-80"C and the highest calcite yield was obtained at 30%.Aragonite begins to be formed at the temperature range of 41.0%-53.0%. and the higher temperature is thehigher yield is obtained. pH of the reaction system affect the yield of aragonite, and the yield reaches the highestpercentage at the pH range of 10.0-11.0, and at the conditions of pH 12.3 or over, aragonite is scarcely formed.Vaterlle is fnrmed at the temperature range of 40.0% or less, and transites utterly to calcite within 10-60mmutes in the case of bemg residenced in mother liqmd which C1 is not contained, and within 140hours inthe case of containing CI-.s in the case of containing CI-.

• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.447-454
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• 2012

The objective of this study was to determine the effect of propofol and remifentanil combination on hemodynamics and intraocular pressure (IOP), and to compare with those of isoflurane in beagle dogs. Fourteen clinically healthy beagle dogs were divided randomly into 2 groups and each group was consisted with 7 dogs. Anesthetic agents were propofol (0.2 mg/kg/min) plus remifentanil ($0.5{\mu}g/kg/min$, 1% solution in standard saline) in one group (group PRP) and 3% isoflurane in the other group (group ISF). Anesthesia was maintained for 90 min in the both groups. IOP, blood pressure, heart rate and blood gas values (pH, $PaCO_2$, $PaO_2$, $SaO_2$, $tCO_2$, ${HCO_3}^-$) were recorded at 5, 10, 15, 30, 45, 60, 75 and 90 min in the both groups. IOP values in both eyes were significantly decreased in group PRP compared with those in group ISF. but there were no significant differences between two eyes in each group. Systolic, diastolic and mean blood pressures were significantly decreased in group PRP within the normal range. There were no differences between groups in all blood gas parameters. In this study, propofol and remifentanil combination could provide stable IOP and blood pressure compared with isoflurane.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.5-13
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• 1983

This experiment was carried out to elucidate the thermotolerant properties of a thermophilic bacterium which isolated from soils of the hot springs area and selected for the $\beta$-galactosidase production. Biochemical and physiological characteristics of this strain were studied, including the investigation on the fatty acid composition for its neutral fats. The results obtained were summarized as follows. 1. This bacterium was identified as a strain belong to the genus Thermus. 2. Optimal temperature and pH for growth of this strain were $65^{\circ}C$ and pH 6.5 respectively, and it was found to be an absolute thermophilic bacterium which could not grow at 37$^{\circ}C$. 3. No growth was obtained in the medium which contained more than 1.0% of sodium chloride. 4. The tolerable concentration of antobiotics were 10$\mu\textrm{g}$ of penicillin G per $m\ell$ of medium and 0.5$\mu\textrm{g}$ of chloramphenicol per $m\ell$ respectively 5. This strain had autotrophilic requirements for calcium-pantothenate and pyridoxine-HCO as an-essential factor and for niacin as a stimulative factor. 6. Fatty acid composition of neutral fats of the strain was palmitic acid. 60.20%; lauric acid, 11.8%; myristic acid, 7.56%, behenic acid, 4.25%; capric acid, 1.77%; stearic acid, 2.13%; arachidic acid, 1.53%; and others unidentified, 10.7%.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.44-48
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• 2013

In this work, we have prepared tungsten doped vanadium oxide ($W-VO_2$) particles with a low phase transition temperature. $W-VO_2$ particles were synthesized via thermolysis method using vanadyl (IV) sulfate and ammonium bicarbonate as precursors. The structure and thermochromic property of synthesized $W-VO_2$ particles were investigated by FE-SEM, EDS, XRD, XPS, and DSC analysis. The prepared $W-VO_2$ showed a nearly platy morphology, which indicates that the tungsten was successfully doped in the crystal lattices of $VO_2$. $W-VO_2$ nanoparticles with the size of 60 nm exhibited a monoclinic crystal structure and its chemical composition and surface state were also likely to be close to that of $VO_2$. In addition, the phase transition temperature of $W-VO_2$ was $38.5^{\circ}C$, which was approximately $29.2^{\circ}C$ lower than that of pure $VO_2$ ($67.7^{\circ}C$), indicating that the prepared sample had a good reversible thermochromic stability.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.395-406
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• 2002

The sixty natural springs and community wells used as a drinking water in the Daejeon area are mainly located at the parks and the natural green districts. The purpose of this study is to investigate the characteristics of water quality and the contamination of the springs and the wells, and to suggest the management strategy for the springs and wells. For this study, we undertook water quality data from Daejeon City. According to the statistic analysis of water quality data, unacceptable rate as a drinking water was about 28 percent in 1999 and 24.5 percent in 2000, respectively. Major unacceptable factor is coliform, and others are bacteria, yersinia, color, turbidity, Fe and F. The unacceptable rate shows a roughly positive relationship with precipitation, that is, it shows highest rate during a rainy season between June and September. The major contamination source is likely to be the excrement of wild animals around natural springs and wells. Most of springs are vulnerable to the contamination of coliform and bacteria because of short residence time and shallow circulation in subsurface environment. The water samples collected from 31 springs or wells show weak acidic pHs, the electrical conductivity ranging from 63 to 357 $\mu\textrm{S}$/cm, and the hydrochemical types of Na(Ca)-HC0$_3$ and Ca-HC0$_3$. The groundwater samples of low total dissolved solid(TDS) belong to Na(Ca)-HC0$_3$. type, and the groundwater of high total dissolved solid is shifted towards Ca-HC0$_3$ type in the chemical composition. These hydrochemical characteristics indicate that most natural springs is in the early stage of geochemical evolution. The natural springs should be closed during a rainy season, which shows a high contamination rate. We suggest that a protection barrier around the springs should be built to keep wild animals away from the springs.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.7-8
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• 1972

The effects of noise exposure are of two types: Nonauditory effects and auditory effects. Nonauditory effects of noise exposure are interference with communication by speech, sleeping and emotional behavior. The noise will cause the high blood pressure and rapid pulse, also that decrease the salivation and gastric juice. in experimentaly showed that the Corticoid hormon: Gonatotropic hormone were decrease and Thyrotropic hormoone is increase. Auditory effect of noise exposure. when the normal ear is exposed to noise at noise at hamful intensities (above 90㏈) for sufficiently long periods of time, a temoral depression of hearing results, disappearing after minutes or hours of rest. When the exposure longer or intesity greater is reached the Permanent threshold shift called noise-induced hearing loss. Hearing loss resulting from noise exposure presents legal as well as medical problems. The otologist who examines and evaluates the industrial hearing loss cases must be properly informed, not only concerning the otologic but also about the physical and legal aspects of the problems. The measurement of hearing ability is the most important part of a hearing conservation, both preplacement and periodic follow-up tests of hearing. The ideal hearing conservation program would be able to reduce or eliminate the hazardous noise at its source or by acoustic isolation of noisy working area and two ear protections (plugs and muff type) were developed for personal protection.

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.9-13
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• 1998

Purpose: The old reference range of serum anion gap(AG) may be excessive compared with value measured by new electrolyte analyzers. Therefore, we studied to establish a new reference range of AG using an autoanalyzer. Methods: With the use of analyzer(Hitachi 747 by enzymatic methods), serum Na and Cl were measured, and with the use of analyzer(CX-3 by differental rage pH), serum $TCO_2$ was measured. We measured AG(=Na-($Cl+HCO_3$)) in 395 stable patients with normal serum albumin and creatinine levels of the pediatric in-patients and out-patients for preoperative examination from march 1997 to July 1997. Results: The normal serum$ AG(mean{\pm}SD)$ were neonate, $11.2{\pm}3.2$ mEq/L; infancy, $11.8{\pm}2.7$ mEq/L; early childhood, $12{\pm}2.7$ mEq/L; late childhood, $11.7{\pm}3.2$ mEq/L; adolescence, $9.6{\pm}2.7$ mEq/L; adult, $9.0{\pm}2.7$ mEq/L. Normal serum AG in more than 10 years of age was significantly lower than the previous normal value and also the difference of AG between more than 10 years and less than 10 years was statistically significant(P<0.05). Conclusions: We suggest to measure serum AG according to each type of analyzers.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.294-298
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• 1993

The relationship between pH and the activity of ferrous iron in the reduced soil under water-logging was investigated theoretically and experimentally. The results of this study revealed, contrary to hitherto assumed, that the $pH-Fe^{+{+}}$ relationship in the commonly occurring rice soils under reduced condition is close to that in $FeCO_3-CO_2-H_2O$ system, being remote from that in $Fe_3(OH)_8-H_2O$ system and $Fe(OH)_2-H_2O$ system. This indicates that the activity of ferrous iron in the reduced rice soils under water-logging is likely to be governed by $FeCO_3$, neither by $Fe_3(OH)_8$, nor by $Fe(OH)_2$.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.32-38
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• 1996

Effects of microwave heating on the content of phytic acid and phosphorus of soaked soybean were investigated. Phytic acid content of Danwon, Marly and Amsoy cultivars were found to be 19.19 mg, 18.38 mg, and 16.73 mg/g defatted soybean respectively. Inorganic phosphorus content of soybeans was significantly increased during microwave heating, while phytic acid and phytate phosphorus was gradually decreased. Microwave heating was more effective than autoclaving in reducing the phytate contents. It was also found that microwave heating to soybean of low moisture content was more effective than that of high moisture content for decreasing the phytic acid content. Soaking in 2.5% sodium chloride, 2% sodium bicarbonate, and mixed salt solution for 12 hrs was not effective on reducing the contents of phytic acid and phytate phosphorus, but microwave-heating after soaking in above solutions greatly decreased the contents of phytic acid and phytate phosphorus, whereas significantly increased inorganic phosphorus of soybeans.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.347-354
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• 2014

Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this $CO_2$ carbonation technology is an cost-effective technology option for the reduction of greenhouse gas.