• Title/Summary/Keyword: $SrSO_4$

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Evaluation of Leaching Potential of Heavy Metals from Bottom Ashes Generated in Coal-fired Power Plants in Korea (국내 석탄 화력발전소 배출 바닥재의 중금속 용출 가능성 평가)

  • Park, Dongwon;Choi, Hanna;Woo, Nam C.;Kim, Heejoung;Chung, David
    • Journal of Soil and Groundwater Environment
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    • v.18 no.7
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    • pp.32-40
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    • 2013
  • This study was objected to evaluate the potential impact on the groundwater environment of the coal bottom ash used as fill materials on the land surface. From four coal-fired power plants, bottom-ashes were collected and analyzed through sequential extraction and column leaching tests following the meteoric water mobility procedure. The column tests shown leaching heavy metals including Pb, As, B, Cu, Zn, Mn, Ni, Ba, Sr, Sb, V, Cr, Mo, and Hg. The relatively high concentrations of B, Sr, Ba, and V in leachate were attributed to both the higher concentrations in the bottom ash and the relatively higher portion of leachable state, sorbed state, of metals. Bottom-ash samples from the D-plant only show high leaching potential of sulfate ($SO_4$), probably originated from the coal-combustion process, called the Fluidized Bed Combustion. Consequently, to manage recycling bottom ashes as fill materials, an evaluation system should be implemented to test the leaching potentials of metals from the ashes considering the absolute amount of metals and their state of existence in ashes, and the coal-combustion process.

Isolation and Characterization of Stenotrophomonas maltophilia Strains Capable of Degrading Aniline. (아닐린 분해 세균인 Stenotrophomonas maltophilia의 분리 및 특성)

  • 김현주;김진철;김흥태;최경자;최도일;김홍기;조광연
    • Microbiology and Biotechnology Letters
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    • v.28 no.4
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    • pp.202-208
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    • 2000
  • Four bacteria capable of using aniline as a sole source of carbon and energy we4e isolated from river waters. Among them, two strains were identified as Stenotrophomonas maltophilia based on their physiological and biochemical characteristics and 16SrRNA gene sequence and the others as delftia acidovorans. The four strains were able to grow on the mineral salt media containing aniline at concentrations up to 6,000 $\mu\textrm{g}$/ml. Since aniline degradation by S. maltophilia has not been reported so far, the two strains A-s and 51-4 were selected for further studies. They completely utilized aniline in a mineral salt medium containing 300 $\mu\textrm{g}$/ml of aniline as a sole carbon and energy source within 24 hours. Optimum pH and temperature for aniline degradation and cell growth of both strains were 7.0 and $35^{\circ}C$, respectively. In addition, they effectively degraded aniline is waste, underground and river waters containing 300 $\mu\textrm{g}$/ml of aniline. This is the first report of aniline degradation by S. maltophilia strains.

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Influence of NaCl on the Growth and Metabolism of Halomonas salina

  • YUN , SU-HEE;SANG , BYUNG-IN;PARK, DOO-HYUN
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.118-124
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    • 2005
  • In this research, we examined the effect of NaCl on the growth, energy metabolism, and proton motive force of Halomonas salina, and the effect of compatible solutes on the bacterium growing in the high salinity environment. H. salina was isolated from seawater and identified by 16srDNA sequencing. The growth of H. salina was not enhanced by the addition of external compatible solutes (choline and betaine) in the high salinity environment. The resting cells of H. salina absorbed more glucose in the presence of 2.0 M NaCl than in its absence. H. salina did not grow in the medium with either KCl, RbCl, CsCl, $Na_2SO_4$, or $NaNO_3$, in place of NaCl. The optimal concentration of NaCl for the growth of H. salina ranged from 1.4 M to 2.5 M, and the growth yield was decreased in the presence of NaCl below 1.4M and above 2.5M. The activity of isocitrate dehydrogenase, pyruvate dehydrogenase, and malate dehydrogenase of H. salina was not inhibited by NaCl in in vitro test. The proton translocation of H. salina was detected in the presence of NaCl only. These results indicate that NaCl is absolutely required for the normal growth and energy metabolism of H. salina, but the bacterial growth is not enhanced by the compatible solutes added to the growth medium.

Study of the determination of 226Ra in soil using liquid scintillation counter (액체섬광계수기를 이용한 토양 중 226Ra 분석 방법 연구)

  • Jung, Yoonhee;Kim, Hyuncheol;Chung, Kun Ho;Kang, Mun Ja
    • Analytical Science and Technology
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    • v.29 no.2
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    • pp.65-72
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    • 2016
  • This study presented an analytical method for detecting radium in soils using a liquid scintillation counter (LSC). The isotope 226Ra was extracted from soil using the fusion method and then separated from interfering radionuclides using the precipitation method. Radium was coprecipitated as sulfate salts with barium (Ba) and then converted into Ba(Ra)CO3, which is soluble in an acidic solution. The isotope 222Rn, the decay progeny of 226Ra, was trapped in a water immiscible cocktail and analyzed by LSC. The pulse shape analysis (PSA) level was estimated using 90Sr and 226Ra standard solutions. The figure of merit was the highest at PSA 80, while the alpha spillover was the lowest at PSA 80. The counting efficiency was 243 ± 2% in a glass vial. This analytical method was verified with International Atomic Energy Agency (IAEA) reference materials, including IAEA-312, IAEA-314, and IAEA-315. The recovery ranged from 60–82%, while the relative bias between the measured value and the recommended value was less than 10%. The minimum detectable activity was 2.1 Bq kg−1 with dry mass 1 g, the background count rate of 0.02 cpm, the recovery rate of 70% and counting time of 30 min.

Oxygen Vacancy Effects of Two-Dimensional Electron Gas in SrTiO3/KNbO3 Hetero Structure

  • Choi, Woo-Sung;Kang, Min-Gyu;Do, Young-Ho;Jung, Woo-Suk;Ju, Byeong-Kwon;Yoon, Seok-Jin;Yoo, Kwang-Soo;Kang, Chong-Yun
    • Journal of Sensor Science and Technology
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    • v.22 no.4
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    • pp.244-248
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    • 2013
  • The discovery of a two-dimensional electron gas (2DEG) in $LaAlO_3$ (LAO)/$SrTiO_3$ (STO) heterostructure has stimulated intense research activity. We suggest a new structure model based on $KNbO_3$ (KNO) material. The KNO thin films were grown on $TiO_2$-terminated STO substrates as a p-type structure ($NbO_2/KO/TiO_2$) to form a two-dimensional hole gas (2DHG). The STO thin films were grown on KNO/$TiO_2$-terminated STO substrates as an n-type structure to form a 2DEG. Oxygen pressure during the deposition of the KNO and STO thin films was changed so as to determine the effect of oxygen vacancies on 2DEGs. Our results showed conducting behavior in the n-type structure and insulating properties in the p-type structure. When both the KNO and STO thin films were deposited on a $TiO_2$-terminated STO substrate at a low oxygen pressure, the conductivity was found to be higher than that at higher oxygen pressures. Furthermore, the heterostructure formed at various oxygen pressures resulted in structures with different current values. An STO/KNO heterostructure was also grown on the STO substrate, without using the buffered oxide etchant (BOE) treatment, so as to confirm the effects of the polar catastrophe mechanism. An STO/KNO heterostructure grown on an STO substrate without BOE treatment did not exhibit conductivity. Therefore, we expect that the mechanics of 2DEGs in the STO/KNO heterostructures are governed by the oxygen vacancy mechanism and the polar catastrophe mechanism.

Studies on the Kiln Drying Characteristics of Several Commercial Woods of Korea (국산 유용 수종재의 인공건조 특성에 관한 연구)

  • Chung, Byung-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.2 no.2
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    • pp.8-12
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    • 1974
  • 1. If one unity is given to the prongs whose ends touch each other for estimating the internal stresses occuring in it, the internal stresses which are developed in the open prongs can be evaluated by the ratio to the unity. In accordance with the above statement, an equation was derived as follows. For employing this equation, the prongs should be made as shown in Fig. I, and be measured A and B' as indicated in Fig. l. A more precise value will result as the angle (J becomes smaller. $CH=\frac{(A-B') (4W+A) (4W-A)}{2A[(2W+(A-B')][2W-(A-B')]}{\times}100%$ where A is thickness of the prong, B' is the distance between the two prongs shown in Fig. 1 and CH is the value of internal stress expressed by percentage. It precision is not required, the equation can be simplified as follows. $CH=\frac{A-B'}{A}{\times}200%$ 2. Under scheduled drying condition III the kiln, when the weight of a sample board is constant, the moisture content of the shell of a sample board in the case of a normal casehardening is lower than that of the equilibrium moisture content which is indicated by the Forest Products Laboratory, U. S. Department of Agriculture. This result is usually true, especially in a thin sample board. A thick unseasoned or reverse casehardened sample does not follow in the above statement. 3. The results in the comparison of drying rate with five different kinds of wood given in Table 1 show that the these drying rates, i.e., the quantity of water evaporated from the surface area of I centimeter square per hour, are graded by the order of their magnitude as follows. (1) Ginkgo biloba Linne (2) Diospyros Kaki Thumberg. (3) Pinus densiflora Sieb. et Zucc. (4) Larix kaempheri Sargent (5) Castanea crenata Sieb. et Zucc. It is shown, for example, that at the moisture content of 20 percent the highest value revealed by the Ginkgo biloba is in the order of 3.8 times as great as that for Castanea crenata Sieb. & Zucc. which has the lowest value. Especially below the moisture content of 26 percent, the drying rate, i.e., the function of moisture content in percentage, is represented by the linear equation. All of these linear equations are highly significant in testing the confficient of X i. e., moisture content in percentage. In the Table 2, the symbols are expressed as follows; Y is the quantity of water evaporated from the surface area of 1 centimeter square per hour, and X is the moisture content of the percentage. The drying rate is plotted against the moisture content of the percentage as in Fig. 2. 4. One hundred times the ratio(P%) of the number of samples occuring in the CH 4 class (from 76 to 100% of CH ratio) within the total number of saplmes tested to those of the total which underlie the given SR ratio is measured in Table 3. (The 9% indicated above is assumed as the danger probability in percentage). In summarizing above results, the conclusion is in Table 4. NOTE: In Table 4, the column numbers such as 1. 2 and 3 imply as follows, respectively. 1) The minimum SR ratio which does not reveal the CH 4, class is indicated as in the column 1. 2) The extent of SR ratio which is confined in the safety allowance of 30 percent is shown in the column 2. 3) The lowest limitation of SR ratio which gives the most danger probability of 100 percent is shown in column 3. In analyzing above results, it is clear that chestnut and larch easly form internal stress in comparison with persimmon and pine. However, in considering the fact that the revers, casehardening occured in fir and ginkgo, under the same drying condition with the others, it is deduced that fir and ginkgo form normal casehardening with difficulty in comparison with the other species tested. 5. All kinds of drying defects except casehardening are developed when the internal stresses are in excess of the ultimate strength of material in the case of long-lime loading. Under the drying condition at temperature of $170^{\circ}F$ and the lower humidity. the drying defects are not so severe. However, under the same conditions at $200^{\circ}F$, the lower humidity and not end coated, all sample boards develop severe drying defects. Especially the chestnut was very prone to form the drying defects such as casehardening and splitting.

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Physiological Responses and Lactation to Cutaneous Evaporative Heat Loss in Bos indicus, Bos taurus, and Their Crossbreds

  • Jian, Wang;Ke, Yang;Cheng, Lu
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.11
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    • pp.1558-1564
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    • 2015
  • Cutaneous evaporative heat loss in Bos indicus and Bos taurus has been well documented. Nonetheless, how crossbreds with different fractional genetic proportions respond to such circumstances is of interest. A study to examine the physiological responses to cutaneous evaporative heat loss, also lactation period and milk yield, were conducted in Sahiwal (Bos indicus, n = 10, $444{\pm}64.8kg$, $9{\pm}2.9years$), Holstein Friesian (Bos taurus, HF100% (n = 10, $488{\pm}97.9kg$, $6{\pm}2.8years$)) and the following crossbreds: HF50% (n = 10, $355{\pm}40.7kg$, $2{\pm}0years$) and HF87.5% (n = 10, $489{\pm}76.8kg$, $7{\pm}1.8years$). They were allocated so as to determine the physiological responses of sweating rate (SR), respiration rate (RR), rectal temperature (RT), and skin temperature (ST) with and without hair from 06:00 h am to 15:00 h pm. And milk yield during 180 days were collected at days from 30 to 180. The ambient temperature-humidity-index (THI) increased from less than 80 in the early morning to more than 90 in the late afternoon. The interaction of THI and breed were highly affected on SR, RR, RT, and ST (p<0.01). The SR was highest in Sahiwal ($595g/m^2/h$) compared to HF100% ($227g/m^2/h$), and their crossbreds both HF50% ($335g/m^2/h$) and HF87.5% ($299g/m^2/h$). On the other hand, RR was higher in HF87.5% (54 bpm) and both HF100% (48 bpm) and HF50% (42 bpm) than Sahiwal (25 bpm) (p<0.01). The RT showed no significant differences as a result of breed (p>0.05) but did change over time. The ST with and without hair were similar, and was higher in HF100% ($37.4^{\circ}C$; $38.0^{\circ}C$) and their crossbred HF50% ($35.5^{\circ}C$; $35.5^{\circ}C$) and HF87.5% ($37.1^{\circ}C$; $37.9^{\circ}C$) than Sahiwal ($34.8^{\circ}C$; $34.8^{\circ}C$) (p<0.01). Moreover, the early lactation were higher at HF100% (25 kg) and 87.5% (25 kg) than HF50% (23 kg) which were higher than Sahiwal (18 kg) while the peak period of lactation was higher at HF100% (35 kg) than crossbreds both HF87.5% and HF50% (32 kg) which was higher than Sahiwal (26 kg) (p<0.05). In conclusion, sweating and respiration were the main vehicle for dissipating excess body heat for Sahiwal, HF and crossbreds, respectively. The THI at 76 to 80 were the critical points where the physiological responses to elevated temperature displayed change.

Skin safety of the UV Absorbers by Measurement Cytotoxicity High Functional Product with Water-in-Silicone System

  • In-Young Kim;Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.23 no.3
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    • pp.134-146
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    • 1997
  • Consumers have recently preferred to purchase extensive UV intercepting products, which are waterproof and free from side effects on skin. Testing Cytoroxicity in SR method, cell survivial ratio of UV-B interceptors decreased above 0.08W/V%, and so did that of UV-A interceptors above 0.06W/V%. Also, Patch-test of inorganic UV interceptors resulted in no skin irritation even below 10.0 and 11.25. UV interceptors in the sunlight showed yellowish discoloration in 5 to 14 days. In absorption curves, UV-B was most suitable for Octyl methoxycinnamate and UV-A for Butyl methoxy dibenzoylmethane. Fro this reason, Nylonpoly UVA/UVB the material of OMC and BMDM coated with Nylon & polyethylene, was used as the organic UV interceptor. And zinc oxide and titanium dioxide was used as inorganic UV ibterceptors. The appropriate mixture ratio of ZnO and TiO2 was 6 to 4.6% of ZnO, 4% of TiO2 and 5% of Nylonpoly UVA/UVB were all combined with our sunscreen cream. The SPF value of in-vivo applied to a guinea pig was 34.9 and that of in-vivo was 38.5. Cyclomerhicone and dimerthicone were used in water-in-Silicone system. Ceryl diverhicone and sorbitan sesquioleate were used as emulsifiers and MgSO4, 7H2O, Mg-stearate/Mg-Al-stearate copolymer as emulsification stabilizers. In practical application, each SPF duration of O/W type and W/S type containing sunscreen cream of the same content showed that W/S type of sunscreen cream was 5 times as durable as the other. This product is fit for using in swimming, climbing or skiing. This research is to minimize skin trouble used by UV interceptors and to make one with proper softness, skin safety and UV intercepting efficiency.

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Development of a Self-Diagnostic Measurement Index for ISO 26000 Social Responsibility

  • Lee, Myung-Goo;Cho, Han-Jin
    • Land and Housing Review
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    • v.2 no.4
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    • pp.325-344
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    • 2011
  • On November 1, 2010, the release of ISO 26000 was announced. ISO 26000 does not require 3rd party verification. But even though it is a standard that is voluntarily adopted, because the international standard for social responsibility can be applied as a trade barrier or business condition between countries, it cannot be ignored. So it is clear that we need to be alerted and prepared for this. This paper offers to help with such needs through organizations by developing an index that organizations can use to understand their current situation and diagnose themselves. This paper conducts a comparative analysis between the 7 core subjects and issues of ISO 26000, the existing indexes used by national institutions and the guideline for sustainable management report, the GRI, with the goal of developing a self-diagnostic index that organizations can utilize in order to diagnose their level of social responsibility. It is divided into the 7 core subjects with 181 measurement issues. There are 7 quantitative issues and 164 qualitative issues. The core subjects, excluding governance, are each alloted 14 points, while governance is alloted with 16 points, for a total score of 100 points. This paper is significant in that it is the first index to make self-diagnostic possible.

The Effects of Pulse Current on the Surface Appearance of Chromium Plating (크롬 전착층의 표면광택에 미치는 펄스도금의 영향)

  • 한성호;권식철;여운관
    • Journal of the Korean institute of surface engineering
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    • v.14 no.4
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    • pp.215-220
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    • 1981
  • The surface appearance of chromium electrodeposit was studied by employing a pulse curr-ent plating in self-regulating high speed (SRHS) bath containing 20 g/$\ell$, K2SiF6 7.5 g/$\ell$ SrSO4 and 250 g/$\ell$ CrO3. As the pulse frequency increased, the surface appearance changed suddenly from bright a-ppearance in a direct current plating condition to gray one in the range of pulse frequency less than about 20KHz. However the bright appearance is recovered as the pulse frequen-cy exceeded 20 KHz. This phenomena seemed to be related with the preferred orientation of electrodeposits, considering the relationship between the preferred orientation of elect-rodeposits and surface appearance in a SRHS bath. Direct current plating was also applied to both Sargent and SRHS bath and investigat-ion on surface appearance was extended to the high current density of 400 A/dm2. In a Sa-rgent bath, the increase in bath temperature was necessary for bright appearance as the current density was increased within 150 A/dm2, but bright region was shown in the cons-tant temperature of 70-75$^{\circ}C$ above the current density of 150A/dm2. On the other hand, two regions of surface brightness was found in a SRHS bath. One is region in the low temperature less than 25$^{\circ}C$ and the other in the moderate temperature range from 55$^{\circ}C$ to 65$^{\circ}C$.

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