• 한국초지조사료학회지
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• 제24권3호
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• pp.245-252
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• 2004

톱밥발효돈분의 시용이 혼파초지의 식생구성비율, 건물수량, 양분생산성 및 토양의 화학성 변화에 미치는 영향을 구명하기 위하여 톱밥발효돈분 처리구, 톱밥발효돈분+화학비료 혼용 시용구 및 화학비료표준 시용구 등 8 처리로 하여 4년간 수행된 결과, 평균 건물수량은 대조구 및 퇴비 $50\%$ 시용구를 제외하고는 처리별 비슷한 경향을 보였다. 식생구성은 전처리 공히 시험년차가 경과될수록 두과와 잡초의 비율이 증가하였고, 4년차의 두과비율은 대체적으로 발효돈분 시용구($39{\sim}43\%$)>겸용 시용구($30{\sim}41\%$)>화학비료 시용구($32\%$) 순으로 높았다. 잡초의 식생변화는 발효돈분 처리구에서 보다 화학비료 처리구에서 잡초의 비율은 높았다. 혼파목초의 TDN과 NEL 등 양분생산량은 화학비료 표준시용 대신 질소기준으로 톱밥발효돈분 전량시용이나 또는 톱밥발효돈분($75\%$)+화학비료시용($25\%$) 혼용시용 만으로도 대등한 수량을 얻었다. 혼파 목초 중 인산, 가리 및 마그네슘 함량은 화학비료 표준처리구에 비해서 톱밥발효돈분 시용구에 높았으며 시용량이 많은 처리구일수록 더 높았다. 이에 비해서 칼슘 함량은 일관성이 없었다. 혼파목초의 K/(Ca+Mg) 당량비는 톱밥발효돈분 시용량이 많은 처리구에서 다소 높게 나타났다. 화학비료를 대치할 톱밥발효돈분 시용량의 비율을 $75\%$ 이상으로 할 경우, 3년이상 연용은 과도한 인산의 축적이 우려된다. 톱밥발효돈분 시용에 따른 토양의 pH, 유기물 함량, $Ca^{++},\;Mg^{++},\;K^+$ 치환성 이온 그리고 양이온치환 용량은 시험전보다 시험 후 높아졌으며, 특히 톱밥발효돈분 시용량이 많을수록 높았다.\%$로, 조회분 함량은 $8.4\%$에서 $6.8\%$로 낮아지는 경향이었다.RG, 6월 상순으로 벼 이앙시기가 늦을 경우에는 5월 하순 수확도 가능하면서 생산성과 사료가치가 높은 밀이 권장되었다.는 후반기에 심한 수량감소를 나타냈다. Fe/Mn/Cu/Zn 비율시험에서 white clover는 Cu와 Zn 처리에서 다소 양호한 수량을 보였고 이는 아마도 균형된 Fe/Mn 비율과도 연관된 것으로 보였다.라인목록에서는 알고 있는 자료일 때에는 서명이, 주제탐색일 경우에는 주제 명을 접근 점으로 차이를 보였다. 즉 이용자들은 온라인목록에서의 주제검색기능이 향상된 것으로 여기고 있음을 알 수 있다. 따라서 바람직한 이용자 중심적인 온라인목록에 되기 위해서는 현행시스템의 개선이 요구되는데 이용자들의 주제검색요구를 만족시킬 수 있도록 주제 명 접근을 허용하는 시스템으로의 전환이 요구된다고 하겠다.tology & venereal diseases(3.02)와 Engineering, biomedical(3.75)도 국제적으로 영향력 있는 학술지에 논문 발표실적이 뛰어난 의학분야이다.체수의 $27.6\%$를 차지하고 있으며, 3시간 간출 시간에서는 27.8개체로서 $15.4\%$, 그리고 6시간 간출 시간에서는 15.2개체로서 $29.9\%$를 차지하여 기타 조개류의 채집량은 1시간, 3시간, 6시간 간출 장소의 순으로서 간출 시간이 증가함에 따라 감소하는 경향을 나타내었고, 그 비율은 6시간, 1시간, 3시간의 순으로 높았다.TEX>$10.5\%o\~31.5\%o$ 범위가 최적한 조건인 듯 하다.대한 새로운 지식과 함께 이용자들의 인식을 연구할 수 있는, 철학적이고 방법론적인 연구를 계속하나가면서, 이용자들의 행동패턴을 어떻게 시스템

• 동의생리병리학회지
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• 제23권1호
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• pp.135-143
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• 2009

There is currently increased interest in the identification of antioxidant compounds that are pharmacologically potent and have low or no side effects. Plants produce significant amounts of antioxidants to prevent the oxidative stress caused by photons and oxygen, therefore they represent a potential source of new compounds with antioxidant activity. Moutan Root Sark (MRS) has been frequently used as analgesic. antispasmodic, anti-inflammatory and remedies for female diseases. In this study. the antioxidant activity of extract from MRS was studied in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$ induced human LDL oxidation and the inhibitory effect on collagen induced platelet aggregation. The MRS extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation and on platelet aggregation. In conclusion, the MRS extracts have anti-oxidative and anti-atherosclerotic effects in vitro system, which can be used for developing pharmaceutical drug against oxidative stress and atherosclerosis.

• 자원리싸이클링
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• 제26권6호
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• pp.84-90
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• 2017

저품위 동 함유 슬러지로부터 회수된 동 조금속을 황산구리 전해액에서 전해정련을 수행하여 고순도 동을 회수하고자 하였다. 유기첨가제 종류 및 농도에 따른 전해정련동 표면 형상 및 조도를 분석하였을 때, gelatin계 유기첨가제 5 ppm 및 thiol계 유기첨가제 5~10 ppm 혼합 조건에서 가장 우수한 표면 형상을 얻을 수 있었다. 건식환원공정을 통해 회수한 철(Fe), 니켈(Ni), 코발트(Co) 및 주석(Sn) 등의 불순물이 함유된 각 86.635, 94.969 및 99.917 wt.% 순도의 동 조금속을 사용하여 전해정련하였고, 순도 3N~4N급 전해정련동을 얻을 수 있었다. 동 조금속, 전해액, 전해정련동의 불순 원소 농도 및 동 순도 등의 분석을 통해, 순도 99.99 wt.% 이상 전해정련동을 회수할 수 있는 전해정련 공정시간 및 동 조금속 순도를 도출하였다.

• 대한치과보철학회지
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• 제19권1호
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• pp.17-27
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• 1981

This study was conducted to determine the chemical composition and the mechanical properties of four commercially available low gold-based crown and bridge alloy produced in Korea. Four dental casting gold-silver-palladium alloys, i.e., A, B, C and D (code of alloys) were selected for the evaluation of chemical composition, ultimate tensile strength, elongation. values and Vickers hardness. The chemical composition of test specimens was analyzed by both emission spectrography and wet gravitation method with a 1.5gm of low gold ingot. The tensile properties and Vickers hardness was determined with cast specimens treated in following three conditions; as-cast, softening heat treatment and hardening heat treatment. The tensile testing bars were cast in accordance with the model designed by Gettleman and Harrison (1969) which was modified from the A. D. A. Specification No. 14 for dental chromium-cobalt casting alloy. Nine tensile test specimens were made from a split silicone mold for each of the test alloys to the size of 2.5mm in diameter and a gauge length of 10mm. All four alloys were handled in accordance with conventional methods used in Type III gold alloys. Ultimate tensile strength and elongation were measured on an Instron Universal Tensile Testing Machine (Model 1125, Japan) operated at a crosshead rate of 0.1cm/min. Elongation values were measured using Digital Measuring Microscope (MS-152, FUSOH, Japan). Vickers hardness was determined with a Vickers Hardness Tester (Model VKH-l, Japan) at a 1.0kg load on a mounted tensile test specimen. The following results were obtained from this study; 1. All tested alloys were composed of Au, Ag, Pd, Cu, Zn and Fe in common. The composition rate of gold for all four alloys was found in the range of $42{\sim}47$ weight % as shown below. Alloy A; Au 45%, Ag 40.2%, Pd 5.76%, others 9.04%. Alloy B; Au 47.1%, Ag 29.03%, Pd 6.98%, others 16.92%. Alloy C; Au 45%, .Ag 26.9%, Pd 6.83%, others 21.07%. Alloy D; Au 41.8%, Ag 34.4%, Pd 6.95%, others 16.85%. 3. The ultimate tensile strength of the four alloys was in the range of $31{\sim}82kg/mm^2$. The test results were shown in the below order from the highest value; As-cast condition; D, B, C, A. Softening heat treament; B, C, D, A. Hardening heat treatment; D, B, C, A. 4. The test :results of the elongation rate for each alloy were in the range of $0.5{\sim}18%$. The test results were shown in the below order from the highest value; As-cast condition; A, D, B, C. Softening heat treatment; A, C, D, B. Hardening heat treatment; C, D, B, A. 5. Vickers hardness for each of the four alloys was in the range of $120{\sim}230$. The test results were shown in the below order from the highest value; As-cast condition; C, B, D, A Softening heat treatment; D, B, C, A. Hardening heat treatment; D, A, C, B. 6. There were no differences in the physical properties between as-cast condition and softening heat treatment.

• 대한환경공학회지
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• 제27권3호
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• pp.293-301
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• 2005

재생골재를 교각안정용 쇄석으로 재활용하기 위하여 다양한 용출방법을 이용하여 미량원소를 포함한 무기이온들의 용출특성을 연구하였다. 본 연구에 적용한 방법은 연속 회분식 용출시험(Continuous batch leaching test: DIN 38414-S4), 가용용출시험(Availability test, NEN 7341), pH 유지 시험(pH-stat test: CEN/TC 292/WG6) 그리고 탱크 확산시험(Tank diffusion test: NEN 7345)등 이다. 기존에 많이 적용되온 EPA의 TCLP와 국내 공정시험법의 경우 빠르고 경제적인 방법으로 고형폐기물의 단기간 용출특성을 파악할 수 있으나 다양한 용출환경에서 장기간 일어나는 용출특성을 판단하기 어려운 점이 있었다. 본 시험에 적용된 방법들은 이러한 제한을 극복하고 보다 다양한 환경에서 일어날 수 있는 용출특성을 평가하고자 하였다. 본 연구에 적용된 시험들은 별도의 위해성 판단 기준이 없다. 그러나 본 시험의 결과들을 위해성 판단을 위해 많이 쓰이는 TCLP와 국내폐기물 공정시험방법의 기준에 비교할 때 접촉시간, pH 조건 등의 용출조건이 더 가혹한 조건에서 이루어졌음에도 두 시험의 위해성 기준에 훨씬 못 미치고 있다. 이는 재생골재를 교각안정용 쇄석으로 활용할 경우 환경위해 정도가 우려할 수준 이하일 것임을 시사한다. 특히 교각안정용 쇄석이 사용될 하천은 물이 정지되지 않고 늘 흐르는 곳으로써 용출된 원소들은 그 자리에 축적되지 않고 분산, 희석되어 그 영향정도는 더 낮아질 것으로 생각된다.

• 한국환경과학회지
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• 제22권7호
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• pp.787-799
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• 2013

The aim of this study was to investigate the accumulation of metallic elements and the control effect of marine pollution caused by ocean dumping in the sediments at a waste disposal area in the Yellow Sea. In July 2009, concentrations of organic matter and metallic elements (Al, Fe, As, Cd, Cr, Co, Hg, Ni, Mn, Pb, and Zn) were measured in surface sediments at the site. The ignition loss (IL) in the surface sediments showed a mean value of 15.4%, about 1.5 times higher than the mean value of the sediments in the coastal areas of Korea. The chemical oxygen demand (COD) at some disposal sites exceeded 20 mg $O_2/g{\cdot}dry$, which signifies the initial concentration of marine sediment pollutants in Japan. The disposal sites contain higher concentrations of Cr, Cu and Zn than the sediments of bays and estuaries that might be contaminated. The magnitude of both metal enrichment factors (EF) and adverse biological effects suggest that pollution with Cr and Ni occurred due to the dumping of waste in the study area. In addition, the geoaccumulation index (Igeo) showed that the surface sediments were moderately contaminated. By the mid-2000s, when the amount of waste dumped at this site was the highest, the concentration of metallic elements was higher than ever recorded. On the other hand, in 2008-09, the need for environmental management was relatively low compare with the peak. As a result, the quality of marine sediment has been enhanced, considering the effect of waste reduction and natural dilution in the disposal area.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.83-95
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• 2012

China has been a top producer and exporter of refined lead products in the world since the year 2000. After the phasing-out of leaded gasoline in the late 1990s, non-ferrous metallurgy and coal combustion have been identified as potential major sources of aerosol lead in China. This paper presents the single particle analytical results of ambient aerosol particles collected near a lead smelter using a scanning electron microscopy- energy dispersive x-ray spectroscopy (SEM-EDX). Aerosol particle samples were collected over a 24-hour period, starting from 8 pm on 31 May 2002, using a high volume TSP sampler. For this near source sample, 73 particles among 377 particles analyzed (accounting for 19.4%) were lead-containing particles mixed with other species (S, Cl, K, Ca, and/or C), which probably appeared to be from a nearby lead smelter. Lead-containing particles of less than $2{\mu}m$ size in the near source sample were most frequently encountered with the relative abundances of 42%. SEM-EDX analysis of individual standard particles, such as PbO, PbS, $PbSO_4$, $PbCl_2$, and $PbCO_3$, was also performed to assist in the clear identification of lead-containing aerosol particles. Lead-containing particles were frequently associated with arsenic and zinc, indicating that the smelter had emitted those species during the non-ferrous metallurgical process. The frequently encountered particles following the lead-containing particles were mineral dust particles, such as aluminosilicates (denoted as AlSi), $SiO_2$, and $CaCO_3$. Nitrate- and sulfate-containing particles were encountered frequently in $2-4{\mu}m$ size range, and existed mostly in the forms of $Ca(NO_3,SO_4)/C$, $(Mg,Ca)SO_4/C$, and $AlSi+(NO_3,SO_4)$. Particles containing metals (e.g., Fe, Cu, and As) in this near source sample had relative abundances of approximately 10%. Although the airborne particles collected near the lead smelter contained elevated levels of lead, other types of particles, such as $CaCO_3$-containing, carbonaceous, metal-containing, nitrates, sulfates, and fly-ash particles, showed the unique signatures of samples influenced by emissions from the lead smelter.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.363-363
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• 2014

Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

• 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.

• 한국수산과학회지
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• 제43권2호
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• pp.146-158
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• 2010

In order to evaluate the characteristics of sediments and pollution by organic matter and metallic elements in intertidal sediments along the southwestern coast of Korea, we measured various geochemical parameters, including the mean grain size (Mz), water content (WC), ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and metallic elements (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, As), in intertidal surface sediments. The Mz of the surface sediments ranged from 2.1 to 8.3$\phi$, indicating that the surface sediments consist of various sedimentary facies, such as sand, slightly gravelly mud, sandy mud, and silt. The IL and COD in surface sediment ranged from 0.8 to 5.5% (mean $2.9\pm1.2%$) and from 3.9 to $13.8\;mgO_2/g{\cdot}dry$ (mean $8.5\pm2.6\;mgO_2/g{\cdot}dry$), respectively, which were lower than the values for surface sediment in areas near fish and shellfish farms or industrial complexes. No AVS was detected at any sampling station, despite various sedimentary facies. Most of metallic elements in surface sediments showed relatively good positive correlations with Mz and IL, which imply that the concentrations of metallic elements are mainly controlled by grain size and the organic matter content. The concentrations of metallic elements, except As, at some stations were considerably lower than those in the Sediment Quality Guideline (Effect Range Low, ERL) proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Similarly, the geoaccumulation index (Igeo) class indicated that pollution by metallic elements in intertidal surface sediment, except As, was moderate or non-existent. Our results imply that the intertidal surface sediments along the southwestern coast of Korea are not polluted by organic matter and metallic elements and are healthy for benthic organisms.