• 한국환경과학회지
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• 제32권10호
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• pp.741-744
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• 2023

This study focused on high school laboratory research and the main purpose was to develop alternative additives for livestock waste and ammonia volatilization methods with high school students as participants and to provide information to business owners based on the results. Compared to the control groups, The bentonite and illite treatment groups had similar ammonia volatilization, pH, EC, and total nitrogen content. In particular, the alum and aluminum chloride mixed treatment group showed low pH and ammonia volatilization, and high EC and total nitrogen content for poultry litter. As a result, when focusing on high school laboratory research, the alum and aluminum chloride mixed agent treatment fulfilled its role as an alternative additive for ammonia reduction. In addition, this approach can be suggested as a method to solve difficulties in adapting to the field through a practical cooperative relationship with livestock farms.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1022-1026
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• 2011

The syntheses of DTPA-bis(amide) conjugates of phosphonated cyclohexane moieties (5a-d) and their Gd(III) complexes of the type $[Gd(L)(H_2O)]{\cdot}nH_2O$ (6a-d; L = 5a-d) are described. All new compounds have been characterized by microanalysis and spectroscopic techniques. High $r_1$ relaxivities of aqueous solutions of 6a-d are observed to be in the range of $10.7-18.3\;mM^{-1}sec^{-1}$, which compare much better than that of $Omniscan^{(R)}$ ($r_1=3.90\;mM^{-1}sec^{-1}$).

• Mycobiology
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• 제32권4호
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• pp.186-189
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• 2004

The study on the cultural characteristics of Bipolaris spicifera was conducted to provide with information for the identification, and inoculation studies, etc. B. spicifera grew well at $30{\sim}35^{\circ}C$ and wide range of pH $5.0{\sim}9.0$. However, the fungal growth was retarded at pH 4.0 and 10.0, respectively. Conidia were germinated with 70% at $30^{\circ}C$ but maintained 50% germination even at $40^{\circ}C$, indicating that this pathogen could infect plants at relatively high temperature. The pathogen could not produce conidia under 24 hr fluorescent light condition for 7 days. In contrast, it produced many more conidia at 24 hr dark condition.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.534-541
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• 2021

In this study, a novel microwave-matrix reformer was proposed to convert CH₄, which is a major component, to a high quality hydrogen energy. And to identify this performance, it was investigated for O₂/C ratio, steam feed amount and reformed gas recirculation which are affected for methane conversion and product gas yield. Through the parametric screening studies, optimal operating conditions were that O₂/C ratio, steam feed amount and recirculation rate were 1.1, 10 mL/min and 30 L/min. In this conditions, CH₄ conversion was 68.1%, H₂ selectivity 77.2 and H₂/CO ratio 2.62 which are possible applying SOFC stack for RPG (residential power generator).

• 환경생물
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• 제22권1호
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• pp.111-119
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• 2004

2002년 12월부터 2003년 9월까지 파로호의 어류상 및 어류군집을 조사한 결과는 다음과 같다. 조사된 어류는 총 12과 45종이었다. 한국고유종은 H. mylodon, A. yanatsutae, C. herzi 등 15종 (33.33％)이었다. 우점종은 Z. platypus (72.41％), 아우점종은 H. labeo (9.75％)였고 우세종은 O. uncirostris amurensis (5.98％), Z. temmincki (2.42％), R. brunneus (2.01％), H. olidus (0.88％) 등이었다. 채집된 어종들의 생체량은 Z. platypus 82,863.15g, H. labeo 32,942.63 g, O. uncirostris amurensis 27,482.39 g, C. carpio 6,502.87 g, A. japonica 3,022.15 g,S. scherzeri 2,711.05g의 순으로 나타났다. 파로호에서 확인된 도입종은 A.japonica, H. eigenmanni, H. olidus, O. masou masou, C. urotaenius, R. giurinus, C. carpio (Israeli type), C. cuvieri, M. salmoides, L. macrochirus의 10종이었다. 이 중 C. carpio (Israeli type), C. cuvieri, M. salmoides, L. macrochirus는 국외종이며 A. japonica, H. eigenmanni, H. olidus, O. masou masou, C. urotaenius, R. giurinus는 국내 다른 하천으로부터 도입된 종이다.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.573-584
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• 2021

Hydrogen is evaluated as one of the new energy sources that can overcome the limitations and pollution problems of conventional fossil fuels. Although hydrogen is CO₂-free, attention is required in NO_x emission and flame stability in order to use hydrogen in existing gas fuel system. However, use of electric grids is an unrealistic strategy for decarbonization for residential and commercial heating. Instead, use of H₂ that utilizes city gas grid is suggested as a reasonable alternative in terms of compatibility with existing systems, economic feasibility, and accessibility. In this study, the thermal efficiency and NO_x performance of the boiler according to the H₂ mixture ratio and vapor humidified ratio are reviewed for a humidified NG-H₂ boiler that vapor humidity to combustion air. Mixed fuel with H₂ (20%) is almost similar to NG in terms of efficiency, flame temperature, and pollution performance. Thus, it is expected to be directly compatible with the existing NG system. If the exhaust temperature of the H₂ boiler is lowered to around 60℃ at a humidified ratio of 15-20%, the NO_x emission concentration can be suppressed to about 5-10 ppm. The level of efficiency reaches 87% of the rated load efficiency, which is equivalent to the highest grade achievable.

• 대한화학회지
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• 제49권4호
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• pp.381-388
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• 2005

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2351-2357
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• 2011

Three new metal-organic copper(II) complexes, $[Cu(H_2PZTC)_2]_n{\cdot}2nH_2O$ (1), $[Cu(HPZTC){\cdot}2H_2O]_n{\cdot}2nH_2O$ (2), and $Cu_2[(PZHD)(OH)(H_2O)_2]_n$ (3) ($H_3PZTC$ = pyrazine-2,3,5-tricarboxylic acid, $PZHD^{3-}$ = 2-hydroxypyrazine-3,5-dicarboxylate), have been synthesized from $Cu(II)/H_3PZTC$ system under different synthetic conditions, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. In complexes 1 and 2, $H_3PZTC$ ligands loose one and two protons, which were transformed into $H_2PZTC^-$ anion and $HPZTC^{2-}$ dianion under different preparation condition, respectively. Furthermore, two ligands coordinate with Cu(II) cations in different modes, leading to the formation of the different chain structures. In complex 3, $H_3PZTC$ ligand was converted into a new ligand-PZHD by in situ decarboxylation and hydroxylation under a higher pH value than that for complexes 1 and 2. PZHD ligands link the Cu(II) cations to form a 2D layer structure. These results demonstrate that the preparation conditions, including pH value and reaction temperature etc, play an important role in the construction of complexes based on $H_3PZTC$ ligand.

• 한국결정성장학회지
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• 제10권4호
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• pp.318-323
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• 2000

수화된 아연에 알킬술폰이 층간 삽입된 화합물을 합성하였다. 고온 X-선 회절 데이타와 적외선 스펙트럼, 그리고 분자의 크기로 부터 층간 삽입된 알킬술폰의 공간배열의 온도 의존성을 확인하였다. 온도 구간 1에서는 ${Zn(H_2O_6]^{2+}[C_nH_{2n+1}SO_3]_2\;^-$구조를 가지며 여섯 개로 수화된 아연층에 알킬술폰이 $32.9^{\circ}$로 경사진 이중층 구조를 가짐을 확인하였다. 온도구간 2에서는 ${Zn(H_2O_4]^{2+}[C_nH_{2n+1}SO_3]_2\;^-$구조를 가지며 네개로 수화된 아연층에 알킬술폰이 $55.2^{\circ}$로 경사진 이중층 구조를 가짐을 확인하였다. 온도 구간 3에서는 알킬술폰이 아연금속에 직접 결합된 ${Zn(C_nH_{2n+1}SO_3)_2$구조를 가지고 있으며 $76.5^{\circ}$의 큰 경사각을 유지하면서 이중층 구조를 가짐을 확인하였다.

• 한국수정란이식학회지
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• 제32권3호
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• pp.111-122
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• 2017

The objective of this experiment was to explore the effects of Roscovitine (Rosco) prior to in vitro maturation (IVM) of immature pig oocyte. Brilliant cresyl blue test has been used to select the good quality of oocyte. Specifically, the effects of Rosco exposure on nuclear and cytoplasmic maturation, diameter, intracellular glutathione (GSH) and reactive oxygen species (ROS), and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), and gene expression levels in SCNT embryos have been measured. Cumulus oocyte complexes (COCs) have been exposed in $75{\mu}M$ of Rosco for 22 and 44 h. The COCs that were matured in the IVM for 44 h without Rosco used as control group. Diameter of matured porcine oocytes 44 h culture with Rosco was significantly lower than 22 h culture with Rosco and control groups. GSH was higher in control group than 22 h and 44 h with Rosco but reduction of ROS in 22 h than 44 h with Rosco. In PA, exposure with Rosco 44 h oocytes group has been significantly lower than 22 h and control group in rates of maturation, cleavage and blastocyst formation. Similarly, in SCNT embryos rates of maturation, cleavage and formation of blastocyst have been also significantly lower in 44 h Rosco treated group than other two groups. SCNT embryos treated with Rosco 22 h showed greater expression levels of POU5F1, DPPA2 and NDP52Il mRNA compared with other two groups. Our results demonstrate that Rosco treatment with 22 h prior to IVM improves the development competence of porcine oocyte.