• 한국어병학회지
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• 제36권2호
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• pp.349-360
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• 2023

Common carp (Cyprinus carpio) (Weight 23.05 ± 6.98 g, Length 12.65 ± 1.38 cm) were exposed to waterborne nitrite at 0, 50, 100, 200, 400 and 800 mg NO₂ ^-/L for 96 hours. The lethal concentration 50 (LC₅₀) of C. carpio exposed to waterborne nitrite was 398.6 mg NO₂ ^-/L. Hemoglobin, hematocrit and RBC count were significantly decreased by waterborne nitrite exposure. The MCV (mean mean corpuscular volume) (µl), MCH (mean corpuscular hemoglobin) (pg) and MCHC (mean corpuscular hemoglobin concentration) (%) were significantly increased. The inorganic component, plasma calcium, was significantly increased, and the organic components such as plasma cholesterol and total protein were significantly increased showing a similar tendency with calcium. In enzymatic components, the AST and ALT were also significantly increased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of C. carpio.

• 한국세라믹학회지
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• 제42권4호
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• pp.260-268
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• 2005

규조토를 주원료로 사용한 서로 다른 조성비의 세라믹 슬러리를 압출성형하여 내열보호관을 제조하고, 기계적 강도, 미세구조, 탄소분석을 하였다. 입도가 $50\~100\;{\mu}m$ 다공성 규조토를 $60wt\%$로 고정하고, 조성물 변수로써 유$\cdot$무기바인더로 silica sol$(4.3\~7.3\;wt\%)$, CMC(Sodium CarboxyMethyl Cellulose $(6\~9\;wt\%)$) 및 paper powder$(4.7\~7.7\;wt\%)$를 $1\;wt\%$씩 변화시켜 최적의 배합비를 얻었다. 시편의 특성을 조사한 결과, 규조토 $60\;wt\%$에 silica sol $5.3\;wt\%$, CMC $7\;wt\%$를 첨가하였을 경우, 꺽임강도 7.12 MPa, 탄성율 1090 MPa, 압축강도 1.47 MPa, 탄소 $2.3\;wt\%$ 이하로 철강산업에서의 온도$\cdot$성분측정 및 sample 채취를 할 수 있는 용융금속 프로브용 규조토 내열보호관을 제조할 수 있었다.

• 한국수산과학회지
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• 제45권6호
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• pp.586-593
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• 2012

To identify the food component characteristics of seven oysters(four cultured oysters and two wild oysters Crassostrea gigas and one dendely lamellated oyster Ostrea denselamellos Korean name beotgul) in Korea, the proximate, fatty/amino acid, mineral compositions, texture, color, chemical and taste compounds were investigated. The proximate compositions were not significantly different between cultured and wild oysters, whereas beotgul had lower levels of crude protein, ash and lipid content, and a higher carbohydrate content. The amino nitrogen contents of the three main types were 232.8-258.2, 160.5-213.9, and 218.5 mg/100 g, respectively, and the salinities were 1.5-1.7, 1.5-1.8, and 0.9%, respectively. Regarding the muscle texture, the shearing forces were 95-114, 105-132, and 170 g, respectively. Amounts of total amino acids of cultured, wild oysters and beotgul were 9,004-10,198, 8,165-8,942, and 7,767 mg/100 g, respectively. The major amino acids were aspartic acid (Asx), glutamic acid (Glx), proline, alanine, leucine, phenylalanine, lysine and arginine. Regarding inorganic ions, beotgul had much lower Fe and S contents than the cultured and wild oysters. The major fatty acids of cultured and wild oysters were 16:0, 18:0, 16:1n-9, 18:1n-9, 22:1n-9, 16:4n-3, 20:5n-3, and 22:6n-3, and there was little difference between the two. Beotgul had a higher polyenes ratio, i.e., 20:5n-3, and a lower monoenes ratio than the cultured and wild oysters. The free amino acid contents of cultured, wild oysters and beotgul extracts were 1,444-1,620, 1,017-1,277, and 1,144 mg/100 g, respectively, and the major free amino acids were taurine, glutamic acid, glycine, alanine, tryptophan, ornithine, and lysine. There was a little difference in the glycine, tryptophan, ornithine, and arginine contents.

• Journal of the Korean Wood Science and Technology
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• 제48권2호
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• pp.206-216
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• 2020

본 연구는 진주시 소재 우산고로쇠 인공림에서의 수액 채취 시기별 출수량 및 구성성분을 분석하기 위해 수행되었다. 수액채취는 한 달 간격으로 2회에 걸쳐 이루어졌으며, 각 회당 채취목은 각각 소경목(흉고직경 10~20 cm) 5본씩 이었다. 일평균 기온이 1.16 ± 2.15℃로 조사된 1차 시기(2019년 1월 10일 ~ 2월 09일)의 수액 총 출수일이 약 32일, 총 출수량은 약 60.59 L로 관찰되었다. 일평균 기온이 2.55 ± 1.30℃로 조사된 2차 시기(2019년 2월 12 ~ 22일)에는 총 출수일이 약 11일이었으며 총 출수량은 약 13.38 L로 1차 시기 기준의 약 22%에 해당하는 양으로 감소하였다. 1, 2차 채취 시기별 수액의 당 성분 분석 결과 자당(Sucrose)의 함량이 출수초기 최고 2.5%를 나타냈으며 출수 종료시점에는 최소 0.8% 대로 감소하였다. 포도당(Glucose)과 과당(Fructose)은 Sucrose에 비하여 함량이 낮았으며, 0에 가까운 수치를 나타내었다. 채취 수액의 무기성분 분석 결과, 주요 성분은 칼륨(41.69 ~ 89.75 mg/kg), 칼슘(24.66 ~ 48.14 mg/kg), 마그네슘(10.18 ~ 27.25 mg/kg)이었다. 1, 2차 채취 시기별 수액 간의 sucrose함량 및 무기성분의 함량 범위는 유의적인 차이를 보이지는 않았다. 결과적으로 시기를 달리한 우산고로쇠 수액 채취에 있어서 출수량은 큰 차이를 보였지만 당 및 무기성분 함량의 경우에는 유의적 차이가 나타나지는 않았다.

• 한국대기환경학회지
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• 제32권5호
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• pp.501-512
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• 2016

The study evaluated methods to measure condensable fine particles in flue gases and measured particulate matter by fuel and material to get precise concentrations and quantities. As a result of the method evaluation, it is required to improve test methods for measuring Condensable Particulate Matter (CPM) emitted after the conventional Filterable Particulate Matter (FPM) measurement process. Relative Standard Deviation (RSD) based on the evaluated analysis process showed that RSD percentages of FPM and CPM were around 27.0~139.5%. As errors in the process of CPM measurement and analysis can be caused while separating and dehydrating organic and inorganic materials from condensed liquid samples, transporting samples, and titrating ammonium hydroxide in the sample, it is required to comply with the exact test procedures. As for characteristics of FPM and CPM concentrations, CPM had about 1.6~63 times higher concentrations than FPM, and CPM caused huge increase in PM mass concentrations. Also, emission concentrations and quantities varied according to the characteristics of each fuel, the size of emitting facilities, operational conditions of emitters, etc. PM in the flue gases mostly consisted of CPM (61~99%), and the result of organic/inorganic component analysis revealed that organic dusts accounted for 30~88%. High-efficiency prevention facilities also had high concentrations of CPM due to large amounts of $NO_x$, and the more fuels, the more inorganic dusts. As a result of comparison between emission coefficients by fuel and the EPA AP-42, FPM had lower result values compared to that in the US materials, and CPM had higher values than FPM. For the emission coefficients of the total PM (FPM+CPM) by industry, that of thermal power stations (bituminous coal) was 71.64 g/ton, and cement manufacturing facility (blended fuels) 18.90 g/ton. In order to estimate emission quantities and coefficients proper to the circumstances of air pollutant-emitting facilities in Korea, measurement data need to be calculated in stages by facility condition according to the CPM measurement method in the study. About 80% of PM in flue gases are CPM, and a half of which are organic dusts that are mostly unknown yet. For effective management and control of PM in flue gases, it is necessary to identify the current conditions through quantitative and qualitative analysis of harmful organic substances, and have more interest in and conduct studies on unknown materials' measurements and behaviors.

• 해양환경안전학회지
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• 제22권2호
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• pp.212-219
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• 2016

동해 남서해역과 같이 용존 무기 질소(dissolved inorganic nitrogen; DIN)가 제한된 환경에서 우점 규조류 Chaetoceros debilis와 Leptocylindrus danicus의 용존 유기 질소(dissolved organic nitrogen; DON)의 이용성을 정량적으로 평가하였다. 질소원으로 DIN은 질산염과 암모늄, DON은 동해에서 중요한 비율을 차지하는 글리신(glycine)과 요소(urea)에 관하여 각각 평가하였다. Monod 식으로부터 유도한 C. debilis의 최대생장속도(${\mu}_{max}$)와 반포화상수(Ks)는 질산염에서 $1.50day^{-1}$와 $1.62{\mu}M$, 암모늄에서 $1.13day^{-1}$와 $6.97{\mu}M$, 글리신 $1.46day^{-1}$와 $3.36{\mu}M$, 요소 $0.93day^{-1}$와 $0.55{\mu}M$으로 나타났다. 또한 L. danicus는 질산염에서 $1.55day^{-1}$와 $5.21{\mu}M$, 암모늄에서 $1.57day^{-1}$와 $4.57{\mu}M$, 글리신 $1.47day^{-1}$와 $3.80{\mu}M$, 요소 $1.42day^{-1}$와 $1.94{\mu}M$이었다. 두 종 모두 요소에서 용존 무기 질소보다 상대적으로 높은 친화성이 확인되었으며, 이러한 높은 친화성은 DIN 제한된 상태에서 C. debilis와 L. danicus이 생장을 유지하기 위해 요소를 이용할 것으로 판단되어진다. 따라서 동해 남서해역과 같이 DIN이 제한된 해역의 경우, DON의 효율적인 이용이 식물플랑크톤의 우점화 전략에서 중요한 요인 중 하나로 생각된다.

• 청정기술
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• 제6권1호
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• pp.61-69
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• 2000

본 연구에서는 시멘트 산업에서 이용 가능한 무기질 산업폐기물의 발생현황 및 물성을 조사하여 시멘트원료, mineralizer/flux, 시멘트 혼합재, 특수시멘트 제조원료 등 용도별 재활용 방안을 결정하고 적용실험을 하였다. 산업폐기물의 시멘트 원료로의 이용에 있어, 철질원료 대체용으로는 Cu-slag, Zn-slag, 전기로 슬래그 및 전로 슬래그 등이, 규석질 원료의 대체용으로 폐주물사가 사용되었다. 제당회사에서 발생되는 $CaF_2$가 주성분인 폐소석회와 아연제련 공정에서 부산되는 폐기물인 jarosite를 mineralizer/flux로 사용하여 클린커의 소성온도를 약 $100{\sim}150^{\circ}C$ 낮출 수 있었다. 혼합재료의 이용에 있어, Cu-slag와 STS sludge를 혼합 첨가한 경우 시멘트 혼합재로서의 충분한 물성을 얻을 수 있었고, fly ash 및 석회석도 시멘트의 혼합재로 적당량 첨가함으로서 시멘트의 성능을 향상시킬 수 있었다. 특수 시멘트의 원료로의 이용에 있어서는, 알루미늄 폐슬러지를 원료로 속경성 클린커를 제조하고 이를 이용하여 2시간내에 $300kg/cm^2$강도를 발현하는 초속경 시멘트를 제조하였고, 두 종류의 도시쓰레기 소각회를 원료로 이용하여 $C_3S(3CaO{\cdot}SiO_2)$와 $C_{11}A_7{\cdot}CaCl_2(11CaO{\cdot}7Al_2O_3{\cdot}CaCl_2)$가 주요 광물인 시멘트를 제조할 수 있었다.

• 한국대기환경학회지
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• 제32권5호
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• pp.485-500
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• 2016

We examined acidity state of inorganic aerosol and oxidation state of organic aerosol by High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) at Baengnyeong Super site from Jan 2012 to Dec 2013. Additionally, we carried out the analysis for the aerosol component group of organic matter ($C_xH_y$, $C_xH_yO_1$, $C_xH_yO_z$, $C_xH_yO_zN_p$) and elemental composition to calculate H/C, O/C, N/C, OM/OC and identify the oxidation state. The aerosol chemical composition in this study is dominated by sulfate ($SO_4{^{2-}}$), nitrate ($NO_3{^-}$) plays a smaller role in aerosol acidity. Ammonium ($NH_4{^+}$) was found in a formation of $(NH_4)_3H(SO_4)_2$. However, the binding formations of $NH_4NO_3$ and $NH_4Cl$ increase in the winter. $C_xH_yO_1$ indicating the oxidized state of $PM_{1.0}$ has the highest ratio of 41% while $C_xH_y$ indicating the non-oxidized state has a lower ratio of 36%, meaning that the oxidation level of $PM_{1.0}$ in Baengnyeong Island is high. The ratio between H/C and O/C was 1.33 and 0.78 respectively, showing the characteristic of LV-OOA (Low volatility-Oxygenated Organic Aerosol). Acidic and oxidized aerosols sampled during this field study were largely anthropogenic in origin from Chinese continent and photochemically aged.

• 한국응용과학기술학회지
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• 제24권2호
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• pp.174-181
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• 2007

본 연구에서는 졸-겔 공법을 이용하여 가스 차단 특성을 갖는 $SiO_2/EVOH$(에틸렌 비닐알콜 공중합체) 하이브리드 물질을 제조하였다. 제조된 여러 조성의 하이브리드 졸을 표면 처리한 biaxially oriented polypropylene (BOPP) 기지재에 스핀 코팅 방식을 이용하여 코팅하였다. X선 회절 및 DSC 분석에 의해 하이브리드 내의 EVOH 상과 실리카 상 사이의 결합에 따른 결정화 거동의 변화를 조사하였다. 또한 $SiO_2/EVOH$ 하이브리드 겔의 모폴로지 관찰을 통하여, 100nm 이하의 실리카 입자들이 균열하게 분산된 매우 치밀한 상 미세구조를 갖는 하이브리드 물질을 제조하기 위해 필요한 Tetraethylorthosilicate (TEOS) 무기전구체의 최적 함량이 존재함을 알 수 있었다. 첨가된 TEOS 함량이 최적 함량보다 낮거나 높은 경우에는 큰 도메인의 입자 클러스터들이 형성되어 매우 불안정한 모폴로지를 나타내는 상분리 현상이 관찰되었다. 이러한 모폴로지 결과는 하이브리드 코팅 필름의 산소 투과도의 변화 결과와 일치하였는데, TEOS 함량이 0.01 - 0.02mol로 첨가되어 제조된 하이브리드로 코팅된 필름의 경우 매우 우수한 산소 차단 특성을 나타냈으며, 0.04mol 이상으로 첨가되었을 때는 상 분리 및 미세 균열 발생으로 인하여 그 차단 특성이 급격하게 감소하는 것으로 나타났다.

• 대한치과기공학회지
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• 제29권1호
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• pp.121-131
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• 2007

A preparation process's conditions of aqueous sol which contains anatase-type nano titania particles with photocatalyic properties was established by using Yoldas process, so called, DCS(Destabilization of Colloidal Solution) process in this study. And crystal size change and phase transformation of titania particles in aqueous titania sol depending on reaction conditions was investigated by a light scattering method and XRD analysis of frozen dried powders, respectively. This sol with photo catalytic nano titania particles was used to the following hydrophilic hybrid coating film's fabrication and its properties was evaluated. Subsequently, for coating film using the above mentioned aqueous titania sol, non-aqueous titania sol was prepared without any chemical additives and its time stability according to aging time was investigate. By using the above mentioned aqueous titania sol and non-aqueous sol, a complex oxide coating sol for metal and ceramic substrate and a organic-inorganic hybrid coating sol for polymer substrate was prepared and it's hydrophilicity depending on UV irradiation conditions was evaluated. As a conclusions, the following results were obtained. (1)Aqueous titania sol The average particle size of titania in formed aqueous titania sol was distributed between 20$\sim$90nm range depending on reaction conditions. And the crystal phase of titania powders obtained by frozen drying method was changed from amorphous state to anatase and subsequently transformed to rutile crystal phase and it is attributed to concentration gradient in aqueous sol. (2)Non-aqueous titania sol Non-aqueous titania sol was prepared using methanol as a solvent and a little distilled water for hydrolysis and nitric acid as a catalyst were used. The obtained non-aqueous titania sol was stable at room temperature for 20 days. Additionally, non-aqueous titania sol with addition of chealating reagent such as acethylaceton and ethylene glycol prolonged the stability of sol by six months. (3)Complex sol and hybrid sol with super hydrophilicity The above mentioned aqueous titania sol as a main photocataylic component and non-aqueous titania sol as a binder for coating process was used to prepare a complex sol used for metal, ceramic and wood material substrate and also to prepare the organic-inorganic hybrid sol for polymer substrate such as polycarbonate and polyethylene, in which process APMS(3-Aminopropyltrimethoxysilane), GPTS(3-Glycidoxypropyl-trimethoxysilane) as a hydrophilic silane compound and HEMA(2-Hydroxyethyl methacrylate) as a forming network in hybrid coating film were used. The hybrid coating film such as prepared through this process showed a superhydrophilicity below 1$10^{\circ}$ depending on processing conditions and a pencil's hardness over 6 H.