• 제목/요약/키워드: $Cr_2 O_3$

검색결과 1,268건 처리시간 0.032초

한국산 灰重石鑛의 광물학적, 지화학적 연구 및 그의 探査에의 이용 (The Mineralogical and Geochemical Study on Korean Scheelites and its Application to the Ore Prospecting)

  • So, Chil-Sup;Park, Maeng-Eon
    • 자원환경지질
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    • 제12권2호
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    • pp.79-93
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    • 1979
  • 한반도 내에 부존되고 있는 중적광상들은 세 주요한 Metallousenetic Epoch (Pre-Cambrian E., Jurassic-early Cretaceous E., 및 late Cretaceous-early Tertiary E.)에 생성되었고 성인으로 열수작용과 접촉교대작용에 기인된다고 보고되었다. 이중 12개 광상(달성, 산내, 일광, 상동, 대화, 월악, 복수, 옥방, 쌍전, 홍성, 삼봉, 청양)을 본 연구의 대상으로 택하고 각 지역에서 채취한 표품중 모두 25개 시료에 대하여 지화학적 실험을 수행하였다. 즉 각 분쇄된 시료 (-80+120mesh)는 super panner, 중액, isodynamic separator, UV lamp를 이용한 물리적인 처리과정을 거쳐 최종으로 입체현미경 하에서 단체분리된 후 Jarrell-Ash 1.5m Grating Spectrometer를 이용하여 본 연구대상 시료로 개발한 Spectrochemical method (Carrier: NaCl, Internal standard: $La_2O_3$)로 정량 분석되었다. 본 연구에서 밝혀낸 국내 회중석 광내에 함유되는 희유 윈소의 종류는 모두 Al, Bi, Fe, Si, Mn, Pb, Mg, Sn, Mo, Cu, Sr, Cr, Y, Ag, Ti, Ni, As, Yb의 18개 원소이며, 이들은 각각의 절대적 및 상대적인 함량과 각 광화작용의 시기, 광상의 성인, 모암, 각 원소의 mobility 그리고 회중석광의 형광색 및 육안색과 비교 검토되었다. 본 연구의 결과로 회중석광이 정출되는 과정에서 유사한 지질환경의 물리화학적인 여건이 이루어지면 그 내에 함유되는 몇 성분원소들의 화학적인 특성은 매우 유사성을 보여주는 typochemical habit를 가짐을 알 수 있었다. 본 연구에서 밝혀진 한국산 회중석 광내의 희유성분(稀有成分)으로서 Y, Mn, Sr 원소들의 Geochemical mobility의 특성(特性)은 앞으로 회중석광의 심도탐광을 위하여 고려되어야하고, 더욱 연구개발되어야 할 것이다. 또한 상기 회중석 광내의 물리적 및 화학적으로 결합되어 있는 불순물의 희유성분들은 선광 제련 파정에서 금속성분의 추출농집공정(工程)에 유용한 자료가 될 것이다.

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잉여슬러지를 이용한 저온 열적전처리 및 바이오 가스 특성 평가 (Evaluation of Low-temperature Thermal Pre-treatment and Biogas Characteristics using Waste Activated Sludge)

  • 최재훈;정성엽;김지태
    • 한국물환경학회지
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    • 제35권4호
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    • pp.299-307
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    • 2019
  • The purpose of this study was to investigate the effect of low temperature thermal pre-treatment on biodegradation of waste activated sludge for anaerobic digestion as a countermeasure for increasing sludge generation. The experimental condition was accomplished in 2 %, 4 %, and 6 % TS concentration, and $70^{\circ}C$, $80^{\circ}C$, $90^{\circ}C$ of temperature for a maximum of 120 minutes retention time. Then, it was followed by analysis of physical/chemical properties, BMP test and composition of biogas. The biogas characteristic was evaluated by applying the modified Gomperz model. As a result, solubility of dissolved substrate, such as $SCOD_{Cr}$, soluble carbohydrate, and soluble protein, and biogas production increased as temperature increased. Solubilization efficiency at $90^{\circ}C$ was 18.4 %, 17.03 % and 16.88% in 2 %, 4 %, and 6 % TS concentration respectively. Also, solubilization rates of carbohydrate and protein similarly increased. BMP test results also showed that methane production in excess sludge increased to 0.194, 0.187 and $0.182m^3/kg$ VS. respectively, and lag phase decreased to 0.145, 0.220, 0.351 day due to acceleration of the hydrolysis step. Consequently, low-temperature thermal pre-treatment could increase biodegradability of sludge, positively affecting biogas production and sludge reduction.

Apparent digestibility coefficients of plant feed ingredients for olive flounder (Paralichthys olivaceus)

  • Mostafizur Rahman;Buddhi E. Gunathilaka;Sang-Guan You;Kang-Woong Kim;Sang-Min Lee
    • Fisheries and Aquatic Sciences
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    • 제26권2호
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    • pp.87-96
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    • 2023
  • This study was designed to determine the apparent digestibility coefficients of soybean meal, soy protein concentrate (SPC), soy protein isolate (SPI), rapeseed meal (RSM), pea protein concentrate (PPC), wheat gluten meal (WGM) and wheat flour (WF) for olive flounder, Paralichthys olivaceus. A reference diet (RF) was formulated to meet the nutrient requirements of olive flounder with 1% chromic oxide (Cr2O3) as an inert indicator. Test diets were prepared to contain 70% RF and 30% of the test ingredient. Olive flounder, averaging 150 ± 8.0 g, was cultured in 400-L fiberglass tanks at a density of 25 fish per tank. Fecal collection columns were attached to each tank. Fecal samples were obtained from triplicate groups of fish for 4 weeks. Dry matter digestibility of SPC (75%) and WGM (76%) were significantly higher than the other test ingredients. Protein digestibility of SPC (85%), PPC (88%) and WGM (89%) were significantly higher than the other test ingredients, and protein digestibility of RSM (77%) and WF (76%) was lower than the other ingredients tested. Lipid digestibility of SPC (72%) and SPI (69%) were significantly higher than the other test ingredients. Energy digestibility of SPC (85%) and WGM (82%) were significantly higher than that of others tested ingredients. The availability of amino acids in WGM was generally higher than in other plant-feed ingredients. Therefore, SPC and WGM were seems to be efficient as potential protein sources for olive flounder compared to other tested ingredients. Overall, findings of the current study may assist in more efficient and economical formulation of diets using plant feed ingredients for olive flounder.

제지(製紙)슬러지의 시용(施用)이 논 토양(土壤)의 화학성(化學性)과 수도생육(水稻生育)에 미치는 영향(影響);Ⅰ. 슬러지시용(施用)이 토양중(土壤中) 질소형태(窒素形態) 및 무기성분변화(無機成分變化)에 미치는 영향(影響) (Effects of Paper Sludge Application on the Chemical Properties of Paddy Soil and Growth of Paddy Rice;I. Effects of Paper Sludge Application on the Nitrogen Forms and Inorganic Nutrients of Paddy Soil)

  • 허종수;김광식
    • 한국환경농학회지
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    • 제4권2호
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    • pp.78-87
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    • 1985
  • 제지(製紙)슬러지가 논 토양(土壤)의 화학성(化學性)과 수도생육(水稻生育)에 미치는 영향(影響)을 검토(檢討)하기 위하여 슬러지의 시용량(施用量)을 300, 600, 900 및 1,200㎏/10a 으로 달리하고 각(各) 시용수준별(施用水準別)로 C/N 율(率)을 30 : 1 로 조절(調節)하여 pot 시험(試驗)을 실시(實施)함으로써 토양중(土壤中) 질소(窒素)의 형태변화(形態變化), 유기태질소(有機態窒素)의 무기성분(無機成分) 및 중금속함량변화(重金屬含量變化)를 경시적(經時的)으로 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 토양중(土壤中) amino sugar 및 amino acid 태질소(態窒素), 유기물(有機物) CEC 및 유효규산(有效珪酸)의 함량(含量)은 슬러지구(區)가 3요소구(要素區)에 비(比)하여 증가(增加)하였다. 2) 항온(恒溫) 6주후(週後) 유기태질소(有機態窒素)의 무기화율(無機化率)은 3요소구(要素區)가 12.2%, 슬러지 300㎏/10a 구(區) 12.6%, 슬러지 300㎏/10a의 C/N 율조절구(率調節區) 15.1%, 슬러지 600㎏/10a 구(區) 9.7%, 슬러지 600㎏/10a의 C/N 율조절구(率調節區)는 15.2%로 나타났다. 3) 토양중(土壤中) 동(銅) 및 납의 함량(含量)은 각각(各各) $0{\sim}0.2100$$0{\sim}0.0013$ ppm 범위(範圍)였으며 크롬 및 카드뮴은 검출(檢出)되지 않았고 토양중(土壤中) 이들 중금속함량(重金屬含量)은 처리간(處理間)에 차이(差異)가 없었다.

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통영항의 해수 및 저질의 위생학적 특성 (Sanitary Characteristics of Seawater and Sediments in Tongyeong Harbor)

  • 박준용;김영인;배기성;오광수;최종덕
    • 한국식품위생안전성학회지
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    • 제25권4호
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    • pp.367-375
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    • 2010
  • 이 연구는 통영항 내의 해수와 저질의 특성과 주변횟집의 수질의 품질 특성에 대하여 2008년 6월부터 2009년 5월까지 월 1회 조사를 실시하였으며 그 결과는 다음과 같다. 통영항의 해양수온은 평균 $17.4{\pm}5.77^{\circ}C$, 투명도 평균 $1.9{\pm}0.46$ m, 부유물질 $36.7{\pm}5.00$ mg/L, COD $2.36{\pm}0.80$ mg/L, DO $6.67{\pm}1.54$ mg/L, 염분농도 $32.3{\pm}0.64$‰를 각각 나타내었다. 아질산 질소는 $0.010{\pm}0.005$ mg/L, 질산 질소 $0.050{\pm}0.011$ mg/L, 암모니아 질소 $0.030{\pm}0.007$ mg/L, 인산 인 $0.050{\pm}0.006$ mg/L로 각각 나타났으며, TBT는 검출한계 이하로 검출되었다. 통영항 해수 중의 total coliform은 조사기간 중 < 1.8~22,000 MPN/100 mL 범위에 기하학적 평균값이 164.9 MPN/100 mL이었고 230 MPN/l00 mL을 초과하는 비율은 39.6%를 나타내었다. fecal coliform은 < 1.8~7,900 MPN/100 mL 범위에 기하학적평균값은 33.7 MPN/100 mL, 43 MPN/100 mL을 초과하는 비율은 47.9%로 조사되었다. total coliform에 대한 fecal coliform 검출 비율은 69.2%로 나타났다. 통영항 해수 중의 비브리오는 6월부터 11월에 240주가 검출되었으며, V. alginolyticus가 82주로 34.2%를 차지하여 가장 많이 검출되었고, 그 밖에 parahaemolyticus가 13.8%, V. culnificus 10.0%, V. cholerae non-O1이 0%, V. mimicus 12.5%가 검출되었다. 저질 특성은 함수율이 $56.63{\pm}5.51$ %, 강열감량 $9.20{\pm}1.36$%, COD $7.64{\pm}1.13$ mg/g, AVS $0.07{\pm}0.02$mg/g으로 다른 해역에 비하여 다소 높게 나타났다. 중금속의 함량은 카드뮴(Cd)은 $0.10{\pm}0.05$, 구리(Cu) $4.79{\pm}8.20$, 비소(As) $1.95{\pm}0.17$, 수은(Hg) $0.10{\pm}0.07$, 납은 불검출, 6가크롬은 ($Cr^{6+}$) $0.34{\pm}0.12$, 아연 (Zn) $125.33{\pm}16.40$, 니켈(Ni) $16.34{\pm}1.93$ mg/kg을 나타내었다. 통영항 주변 횟집의 total coliform 및 fecal coliform은 횟집에 따라서 다소 차이가 있었지만 여름철에 주로 검출되었으며, 여름철 집중관리가 요구되었다.

종간교잡 유래 중생 고품질 벼 품종 "화원 1호" (A New Medium-maturity Rice Cultivar Developed from an Interspecific Cross, "Hwaweon 1")

  • 안상낙;구홍광;김동민;오창식;강주원;김봉학;오지민
    • 한국육종학회지
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    • 제41권3호
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    • pp.338-341
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    • 2009
  • "화원1호"는 종간교잡을 통해 화성벼의 근동질계통을 육성하고자 '97년 화성벼와 O. rufipogon을 교배하고, 계속적인 여교배와 MAS(Marker aided selection)를 병행 실시하여 CR101-1-1 계통을 선발하였다. 생산력검정 시험 결과 조사된 형질 중 천립중을 제외한 기타 형질에서는 화성벼와 유사한 근동질계통이었으며, 품종보호원 출원 조건에 부합하여 "화원1호"로 명명하고 품종보호원을 출원하였다. 1. 출수기는 보통기재배에서 8월 10일로 "화성벼와 동일한 중생종 품종이다. 2. 천립중은 23.4 g으로 "화성벼"보다 무겁다. 3. 흰잎마름병에는 이병성이며, 줄무늬잎마름병에는 저항성이다. 5. 도정 특성, 아밀로스 함량은 화성벼와 비슷한 수준이다. 6. "화원 1호"의 정조수량은 '05~'06년 2개년간 실시한 생산력검정 시험에서 평균 7.43 MT/ha로 "화성벼" 대비 110% 수준이었다.

의치상의 종류에 따른 상악 의치상의 유지력에 관한 임상적 연구 (A CLINICAL STUDY ON THE RETENTION OF MAXILLARY COMPLETE DENTURE WITH DIFFERENT DENTURE BASE MATERIALS)

  • 이종혁;임주환;조인호
    • 대한치과보철학회지
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    • 제39권1호
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    • pp.58-70
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    • 2001
  • For the successful treatment of complete denture, obtaining a good retention is essential. There are lots of factors affecting denture retention. Denture material, one of those factors affecting denture retention, was the subject of this study, and internal surface treatment also considered for the method of enhancing denture retention. Two resin(Lucitone $199^{(R)}$(heat cured resin) Vertex $CP^{(R)}$(self cured resin)) and two metal($Biosil^{(R)}$(Co-Cr alloy), $Vitallium^{(R)}$(Co-Cr alloy)) denture base materials were used for making test denture base. Newly developed device was used for measuring denture retention. After the retention was measured. We treated internal surface of test denture base with $50{\mu}m\;Al_2O_3$ powder, under 90psi, for 1 minute. Then the retention was measured again. The result was analyzed with K-S test, one-way ANOVA test and independent t-test to deter mine the significant differences as the 95% level of confidence. The results are as follows : In cases of without internal surface treatment, the retention was increased in order of $Vitallium^{(R)},\;Biosil^{(R)},\;Vertex CP^{(R)}$ and Lucitone $199^{(R)}$. Except between Vertex $CP^{(R)}$ and $Biosil^{(R)}$, retention of the other materials was significantly different (p<0.05). After the treatment of internal surface, the retention was increased in order of $Vitallium^{(R)},\;Biosil^{(R)},\;Lucno\;199^{(R)},\;Vertex\;CP^{(R)}$. Except between Lucitone $199^{(R)}$ and Vertex $CP^{(R)}$, $Vitallium^{(R)}$ and $Biosil^{(R)}$ the retention of remaining groups was significantly different each other (p<0.05). In the matter of each material, after the internal surface treatment the retention was increased with Vertex $CP^{(R)},\;Biosil^{(R)}\;and\;Vitallium^{(R)}$ and the value of differences were statistically significant. When we compare the retention of resin and metal denture base, the retention of both denture bases increased significantly with internal surface treatment, and resin denture base showed better retention. As the results show, selecting denture base material could be an important choice of complete denture treatment. To increase denture retention, internal surface treatment can be considered as a possible method.

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마산항 표층 퇴적물의 유기물 및 금속원소의 분포 (Distribution of Organic Matters and Metallic Elements in the Surface Sediments of Masan Harbor, Korea)

  • 황동운;진현국;김성수;김정대;박종수;김성길
    • 한국수산과학회지
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    • 제39권2호
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    • pp.106-117
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    • 2006
  • We measured the concentrations of organic matter and metallic elements (Al, Fe, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb and Hg) in the surface sediments of Masan Harbor (in the southern sea, Korea) to evaluate the geochemical characters of sediment and the pollutions by organic matter and metallic elements. The mean grain size of the surface sediments in the study area ranged from $5.6{\phi}$ to $7.8{\phi}$, indicating silt sediment. The water content of the surface sediments exceeded 60% except at some stations. The contents of ignition loss (IL), total organic carbon (TOC) and total nitrogen (TN) ranged from 7.2-14.3%, 1.2-3.2%, and 0.10-0.28%, respectively. Based on the C/N ratios, the organic matter in the surface sediments of Masan Harbor may originate from terrigenous sources including fluvial inputs (mainly sewage in urban areas). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) ranged from $11.3-29.9\;mgO_2/g\;dry$ and 0.20-4.47 mgS/g dry, respectively, and low concentrations were observed near a shipping route. In addition, the concentrations of metallic elements showed large spatial variations in Masan Harbor and the distributions of metallic elements were also comparable to those of organic matter. This implies that the distributions of organic matter and metallic elements in the surface sediments of Masan Harbor are mainly controlled by biogenic matter and artificial action (mainly dredging). In addition, we calculated the enrichment facto. (EF) and geoaccumulation index (Igeo) in order to evaluate pollution by metallic elements. The enrichment of metallic elements relative to Al was three to eighteen times higher at the study sites, compared to levels in the Earth's crust except for Fe, Ni and Mn. In addition, the Igeo class indicated that the surface sediments in the study area were moderately to strongly polluted in terms of metallic elements.

전자 빔 물리적 증착(EB-PVD)법으로 코팅된 YSZ 열차폐층의 압흔손상 거동에 대한 하부층의 영향 (Influence of Subsurface Layer on the Indentation Damage Behavior of YSZ Thermal Barrier Coating Layers Deposited by Electron Beam Physical Vapor Deposition)

  • 허용석;박상현;한인섭;우상국;정연길;백운규;이기성
    • 한국세라믹학회지
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    • 제45권9호
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    • pp.549-555
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    • 2008
  • The thermal barrier coating must withstand erosion when subjected to flowing gas and should also maintain good stability and mechanical properties while it must also protect the turbine component from high temperature, hot corrosion, creep, and oxidation during operation. In this study we investigated the influence of subsurface layer, $Al_2O_3$ or NiCrCoAIY bond coat layer, on the indentation damage behavior of YSZ thermal barrier coating layers deposited by electron beam physical vapor deposition (EB-PVD). The bond coat is deposited using different process such as air plasma spray (APS) or spray of high velocity oxygen fuel (HVOF) and the thickness is varied. Hertzian indentation technique is used to induce micro damages on the coated layer. The stress-strain behaviors are characterized by results of the indentation tests.

Digestibility and Nitrogen Balance of Diets that Include Marine Fish Meal, Catfish (Pangasius hypophthalmus) By-product Meal and Silage, and Processing Waste Water in Growing Pigs

  • Thuy, Nguyen Thi;Lindberg, Jan Erik;Ogle, Brian
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권7호
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    • pp.924-930
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    • 2010
  • Ileal and total tract digestibility and nitrogen (N) balance of diets with four different protein sources were determined in growing pigs. The diets were based on rice bran, broken rice and maize meal and contained Tra catfish by-product (CBP), processed using three different methods, and marine fish meal (FM). The CBP diets consisted of the by-product in meal form, ensiled with molasses, and CBP waste water (WWBD). The four diets were fed to four growing pigs fitted with post-valve T-cecum (PVTC) cannulas in a $4{\times}4$ Latin Square design. All experimental diets included $Cr_2O_3$ at 5 g/kg feed as an indigestible marker. The ileal apparent digestibility of organic matter and ether extract was higher on diet WWBD than on the other three diets (p<0.05), and the total tract apparent digestibility was higher on diet WWBD than on the FM diet (p<0.05). The ileal and total tract apparent digestibility of crude protein and amino acids was not significantly different among diets (p>0.05). No significant effects of diet were found on N-retention and N utilization. In conclusion, the catfish by-product meal, ensiled catfish by-product and processing waste water diets and the fish meal diet had similar ileal and total tract apparent digestibility, and similar N utilization in growing pigs.