• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1087-1093
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• 2010

Autotrophic denitrification is known as an effective and economical alternative for heterotrophic denitrification using external carbon sources such as methanol. In this study, we evaluated design and operation parameters for a sulfur denitrification reactor (SDR) treating high strength nitrogen wastewater. The SDR was filled with spherical sulfur media in connected to a pilot-scale nutrient removal process (daily flow rate, $Q=18\;m^3/d$) using moving spongy media. Total nitrogen (TN) concentration of the final effluent was below the 7.0 mg TN/L because nitrate was additionally removed through autotrophic denitrificationin without adding alkalinity (initial alkalinity was $169.4{\pm}20.8\;mg$ $CaCO_3$/L). During the test period, 60~80% of nitrogen in the influent was removed even in low temperature (below $15^{\circ}C$). The alkalinity consumption for nitrate removal in SDR was $4.09{\pm}1.29$ g $CaCO_3/g$ ${NO_3}^-$-N, and the residual alkalinity of influent of SDR was higher than that of theoretical requirements for full conversion of nitrate. The consumption of sulfur was 943.8 g S/d and it was 2.4 times higher than theoretical value (400.1 g S/d) due to abrasion and loss of sulfur media in backwash, etc.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.524-533
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• 2008

Industrial wastewater generated in the electroplating and metal finishing industries typically contain toxic free and complex metal cyanide with various heavy metals. Alkaline chlorination, the normal treatment method destroys only free cyanide, not complex metal cyanide. A novel treatment method has been developed which destroys both free and complex metal cyanide as compared with Practical Plant(I). Prior to the removal of complex metal cyanide by Fe/Zn coprecipitation and removal of others(Cu, Ni), Chromium is reduced from the hexavalent to the trivalent form by Sodium bisulfite(NaHSO$_3$), followed by alkaline-chlorination for the cyanide destruction. The maximum removal efficiency of chromium by reduction was found to be 99.92% under pH 2.0, ORP 250 mV for 0.5 hours. The removal efficiency of complex metal cyanide was max. 98.24%(residual CN: 4.50 mg/L) in pH 9.5, 240 rpm with 3.0 $\times$ 10$^{-4}$ mol of FeSO$_4$/ZnCl$_2$ for 0.5 hours. The removal efficiency of Cu, Ni using both hydroxide and sulfide precipitation was found to be max. 99.9% as Cu in 3.0 mol of Na$_2$S and 93.86% as Ni in 4.0 mol of Na$_2$S under pH 9.0$\sim$10.0, 240 rpm for 0.5 hours. The concentration of residual CN by alkaline-chlorination was 0.21 mg/L(removal efficiencies: 95.33%) under the following conditions; 1st Oxidation : pH 10.0, ORP 350 mV, reaction time 0.5 hours, 2nd Oxidation : pH 8.0, ORP 650 mV, reaction time 0.5 hours. It is important to note that the removal of free and complex metal cyanide from the electroplating wastewater should be employed by chromium reduction, Fe/Zn coprecipitation and, sulfide precipitation, followed by alkaline-chlorination for the Korean permissible limit of wastewater discharge, where the better results could be found as compared to the preceding paper as indicated in practical treatment(I).

• Journal of dental hygiene science
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• v.14 no.2
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• pp.191-197
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• 2014

The purpose of this study was to evaluate the tooth whitening efficacy of 2.9% hydrogen peroxide strip with primer gel of alkaline condition and containing metallic salts as catalyst in-vitro. Hydroxyapatite (HAP) disk was made by compressing and sintering 0.3 g of mixture of HAP powder and polyvinyl alcohol. This HAP disk was stained using modified Stookey's methods. Main bleaching materials were 2.9% hydrogen peroxide strips and the primer gel containing metallic salts as catalyst and pH controller. Stained HAP disks were allocated to each control or experimental groups by color grade. Stained HAP disks were treated for 30 minutes in $37^{\circ}C/80%$ incubator for wetting, then each primer gel according to control or each test group was spread and strips were attached. After 30 minutes for each group strips were detached and HAP disks were washed, dried then color was measured by colorimeter. Efficacy was evaluated by comparing ${\Delta}L$ values of HAP disks at baseline and after treated. Among some kinds of metallic salts for as catalyst, ferric chloride showed best improvement of efficacy and it was statistically significant (p<0.05) compared to control group. Evaluating whitening efficacy according to various pH of primer, efficacy using primer of alkaline condition was increased significantly (p<0.05) compared to control and primers of acidic or neutral conditions. Evaluating whitening efficacy for time course, efficacy of test group for 30 minutes was similar to that of control for 120 minutes. It can be concluded that 2.9% hydrogen peroxide strips using with primer of alkaline condition and containing ferric chloride showed significantly increased whitening efficacy compared to the case of strips only.

• Resources Recycling
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• v.6 no.3
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• pp.3-8
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• 1997

The EA.F. sleelmaking slag (slag that follow) of a cnmvany 1 Co.. containzd a simple substance of a metal, wustlte (FeO), magnetite (Fe,O,), gehlenite (CaAl,SiO,), monlicellite (CaMgSiO,), dc. To recovere a metal (Fe grade . t95%) in the slag, it is desirable that the particles of a metal are isolated from thc slag and madc for a liberated subslance. Then, the liberaled melal is easlly recoveled by a magnetic separation. If thc rcclarnalcd slag, the sizc of which ranges under 40 nun, have a mulli-stage crushing, the most of a metal in thc slag is simply isolaled as a liberated subslance. If the mad, lhat is a liberated subslance and a sphere, is recovered by a magnetic field intensity. the minimum intensity, at which a metal is attracted, is approximately IOOG and did no1 dcpcnd on the particle size of a metad in the same particles. TIe recovered material. that contdined a iron (Fe) over 95% is a metal which is crushed slag by l00G in the multi-stage. If the magnetic field intcns~ty increase, the recovery mcrcasc, but the concentration grade decrease Bewusc thc concentration eams more and more impurities, iron oxide and the coml~ound of alkali earth element. 'll~ercforc If the rccla~nated slag have the multi-stage crushing, the metal is almostly recovered in the crushed slag by lO0G on each particles. If the slag, used as a rcclamatian lhat is a amount of 350,000 tan from I Co., was undcr the multistage crushing and then separaled by 100gauss, it is possible to recova a metal approximately 2.500 Ion, lhat is 0.73% of n ~eclamated slag. in 304.7 mm particles and to recover 4.200 tan in 0.3-1.7 mm particles , that is 1.2% nf a rcclamated slag, in a year. Therefore, ihe told recoverable meld is 6,700 ton, that is 19% of a reclmated slag, in a year, too.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.8-16
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• 2002

This study was performed to produce the high reactive lignin zero substrates from autohydrolyzed wood resources. In chemical compositions of used raw-materials, there were significant differences between two species, Japanese larch (Larix leptolepis) and oak (Quercus mongolica) woods. Japanese larch contained 25 to 3.5 times higher amounts of extractives than oak wood, which is mainly derived from high content of arabinogalactan in Japanese larch wood. Oak wood has 5% lower lignin content and 3% higher holocellulose and pentosans than larch wood. Concerned to changes in wood components during autohydrolysis pretreatment at 22 kg/cm² steaming pressure for 5~60 min, glucose content was constant during pretreatment, while hemicellulose and lignin were abruptly changed. Hemicellulose fraction was decreased significantly and lignin contents increased because of its condensation reaction with hemicellulose degradation products. The pH of hydrolyzates during pretreatment was decreased, reached upto pH 3 and since then leveled off. In the case of oak wood, same tendency was observed as in Japanese larch. Autohydrolysis followed by sodium chlorite and sulfite or bisulfite pretreatment was very effective in delignification of the substrates. In particular, two-stage delignification of autohydrolyzed woods with alkali and O₂-alkali resulted in very low lignin content substrates, such as 0~0.2% lignin substrate.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.304-308
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• 2006

To extract insoluble proteins from silkworm pupa meal, the meal was treated with pretense produced by Bacillus sp. JH-209. The extraction of insoluble silkworm pupa protein was enhanced at alkaline pHs ranged from 7 to 11 by treatment with the protease. The optimum extraction temperature was $40^{\circ}C$ for in soluble protein treated with pretense. The optimum protease treatment time for extraction of protein was 11 hrs and optimum amount of enzyme treated for extraction of protein was 60 Unit, respectively. The treatment of enzyme extracted more protein than ordinary extraction method without pretense. The foaming capacity, foaming stability, emulsion capacity, and emulsion stability of silkworm pupa meal protein extracted by the treatment of the enzymes increased at all pH ranges. Further more oil absorption as well as water absorption capacities of the protein extracted by the treatment of the enzymes were also increased.

• The Korean Journal of Ecology
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• v.23 no.5
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• pp.397-406
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• 2000

In order to clarify the ecophysiological characteristics of Chenopodiaceae which widely distribute on saline and arid habitats, we collected 10 chenopodiaceous plant species, examined their inorganic and organic solute patterns, and confirmed several common physiological characteristics. In spite of high soil Ca/sup 2＋/ contents, chenopodiaceous plants had a little water-soluble Ca within cells, but contained high contents of acid-soluble Ca particularly as a result of Ca-oxalate formation. These plant species also showed accumulation of inorganic ions such as K/sup ＋/, NO₃/sup －/ and Cl/sup －/, and Na/sup ＋/especially in saline habitats instead of K/sup ＋/ Meanwhile, with respect to nitrogen metabolism they retained high N contents in leaves, but showed very low amino acid contents. Additionally, they contained very little proline known to act as a cytoplasmic osmolyte. To ascertain whether this physiological characteristics in the field also can be found under controlled conditions, 7 chenopodiaceous plants (Atriplex gmelini, Corispermum stauntonii, Salicornia herbacea, Suaeda aspayagoides, Suaeda japonica, Chenopodium album var. centrorubrum, C. serotinum) were selected and cultivated under salt treatments. As well as field-grown plants, selected plant species showed similar solute pattern in growth experiment. In summary, the family of Chenopodiaceae represents the following physiological properties; high storage capacity for inorganic ions (especially alkali cations, nitrate and chloride), oxalate synthesis to maintain lower soluble Ca contents within cytoplasm, and low contents of amino acids. In addition to some characteristics mentioned above, the physiological plasticities of Chenopodiaceae which can properly regulate their ion and solute pattern according to soil conditions may enable its representative to grow in dry sand dune and salt marsh habitats.

• Food Science and Preservation
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• v.12 no.4
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• pp.379-386
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• 2005

Free amino acids and polysaccharide content of submerged mycelial culture of Fomitopsis pinicola using $2\%$ citrus peel water extracts(CP), $2\%$ green tea water extracts(GT) and yeast-malt broth(YM) were investigated. Cultivations were conducted at $30^{\circ}C$ and 150 rpm for 10 days. Yields of the mycelium as fresh weight basis in GT-, CP- and YM-broth were $42.3\%,\;34.2\%\;and\;9.89\%$, and their turbidity(OD at 660 nm) of the broth without mycelium were 0.14, 0.16 and 0.22, respectively. Total free amino acid content in the mycelium were 928.19 $mg\%$ in YM, 1060.53 $mg\%$ in CP, 764.83 $mg\%$ in GT, and the major free amino acid was lysine in YM, glutamic acid in CP and GT. Total free exo-amino acid contents were 659.75 $mg\%$ in YM, 954.55 $mg\%$ in CP, 838.69 $mg\%$ in GT, and the major in the all broths was glutamic acid Total amino acid derivatives content of the mycelium were in order of CP>GT>YM, and the major was cystathionine in YM, hydroxy proline in CP and GT. The major among exo-amino derivatives was hydroxy proline in the all broth. Exo-AIS content was in order of CP>GT>YM. Acid soluble polysaccharide content of the mycelium was GT($0.69\%$)>YM($0.39\%$)>CP($0.18\%$). The exo-polysaccharide content was in order of GT($0.87\%$)>CP($0.69\%$)>YM($0.09\%$). Alkali soluble polysaccharide content of the mycelium was in order of CP($5.21\%$)>GT($5.18\%$)>YM($4.56\%$), and exo-polysaccharide was in order of GT($6.79\%$)>YM($3.57\%$)>CP($3.01\%$). The alkali soluble polysaccharide eluted from mycelium cultivated in CP broth was supposed to polysaccharide(about 500,000 daltons) composed of hexose and uronic acid bounded with protein(below 10,000 daltons).

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.261-263
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• 1998

IEEE-1394 버스(이하 13394 버스)는 가정용 가전기기와 컴퓨터를 서로연결 할 수 있는 버스로 100Mbps, 200Mbps, 400Mbps의 광대역폭을 제공하고 데이터를 전달하는 방법으로 비동기 (asynchromous)전송뿐만 아니라 등시성(isochronous)전송도 제공한다. 비동기 전송은 시간의 제약이 없고 정확한 전달이 필요한 데이터에 적합한 반면 등시성 전송은 실시간을 요구하고정확한 전잘이 필요없는 데이터에 적합한 특성을 가진다. 1394 버스는 멀티미디어 데이터를 생성하고 편집하는 장치들을 서로 연결시키고 기존의 LAN이 갖는 대역폭의 부족과 프로토콜살의 실시간 전송 방법의 부재 때문에 진정한 의미의 실시간 구현이 어려웠던 화상 전화기, 화상회의 시스템, 비디오편집 시스템을 가능하게 한다. 이러한 멀티미디어 응용 시스템은1)대용향의 멀티미디어 파일 전송을 필요로 하고 화상전화기 혹은 화상회의 시스템은 2) 고속의 파일 전송을 요구하게 된다. 또 두사람이 화상 전화기를 통해 통신을 하면서 여러 가지 문서를 교환하는 경우 최대한 빠르게 파일 전송이 완료될 필요가 있다. 현재 1394버스에서 IP가 올리는 일이 진행중이므로 기존의 FTP는 사용할 수 없다. 게다가 1394 버스에 IP가 올라가더라도 1394 버스 내에서 대용량의 파일을 더 빠르고 정확하게 전달하기 위해서는 IP오버헤드가 없고 1394 버스의 특성을 직접 이용한 새로운 파일 전송 기법이 필요하다. 1394 버스내에서 대용량의 파일을 빠르고 정확하게 전송하는 기법을 찾기 위해서는 비동기 전송과 등기성 전송의 특성을 잘 이해해야하고 각 전송 방법으로 파일을 전송 할 때 생기는 장단점들을 파악해야한다. 본 논문에서는 비동기 전송과 등기성 전송을 이용한 팔일 전송 기법을 각각 제시하고 실험을 통해 이들의 특성을 비교분석하였다.미에서 uronic acid 함량이 두 배 이상으로 나타났다. 흑미의 uronic acid 함량이 가장 많이 용출된 분획은 sodium hydroxide 부분으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)이 각각 가장 낮았다. 2. 사산(死産)과 초생아사망(初生兒死亡)을 구분(區分)하여 고려해 볼때 사산(死産)은 모성(母性)의 임신력(姙娠歷)과 매우 밀접한 관련이 있는 것으로 사료(思料)되었고 초생아사망(初生兒死亡)은 미숙아(未熟兒)와 이에 관련된 병발이 거의 결정

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.112-118
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• 2012

Steel industry produces many by-products and wastes such as blast furnace slag, electric arc furnace slag, and converter slag. As in the case of rock, the main component of steel slag are CaO and $SiO_2$ ; further, steel slag is as alkaline as portland cement or concrete. Electric arc furnace oxidizing slag is possible to use as an aggregate for concrete ; however, it has been reclaimed because of it's expansibility caused by free CaO. Recently, a innovative rapid cooling method for melting steel slag has been developed in Korea, which reduces free lime content to minimum level and increases the stability of iron oxide. Therefore, this study describes the results of a series of research to utilize globular shape of electric arc furnace oxidizing slag fine aggregates made by rapidly cooled method for the construction industry by cooling rapidly melted slag from the steel industry. First of all, an experiment was carried out to investigate the quality characteristics of rapidly cooled electric arc furnace oxidizing slag fine aggregates in order to determine whether they can be applied to the construction industry. Then, by applying them to concrete of various particle sizes, we explored experimentally the desired condition to apply rapidly cooled electric arc furnace oxidizing slag fine aggregates to concrete.