• Carbon letters
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• 제6권3호
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• pp.141-147
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• 2005

The carbon sample "O", phosphoric acid-activated carbon "OP", zinc chloride-activated carbon "OZ", and two steam activated carbons "OS" and "OS2" with different burn-off of 25% and 58% respectively, were prepared from olive stones. The textural properties were determined from the results of nitrogen adsorption at 77 K and by analyzing these results through the application of different adsorption models. The chemistry of the carbon surfaces was determined from the base neutralization capacities, acid neutralization capacity and surface pH. The sorption of $Pb^{2+}$ ions on to the carbons prepared was followed under dynamic and equilibrium conditions. The differences between the values of the textural parameters were attributed to the inapplicability of some adsorption models and to the heterogeneity of the microporous carbons. The sorption of $Pb^{2+}$ ions is favored on carbon and activated carbons. However, chemically activated carbons are more effective compared with steam-activated ones. The sorption of $Pb^{2+}$ ions were related to the chemistry of the surface rather than to the textural properties.

• Journal of Veterinary Science
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• 제22권4호
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• pp.45.1-45.13
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• 2021

Background: Peste des petits ruminants (PPR) is an infectious disease caused by the peste des petits ruminants virus (PPRV) that mainly produces respiratory symptoms in affected animals, resulting in great losses in the world's agriculture industry every year. Single-domain variable heavy chain (VHH) antibody fragments, also referred to as nanobodies, have high expression yields and other advantages including ease of purification and high solubility. Objectives: The purpose of this study is to obtain a single-domain antibody with good reactivity and high specificity against PPRV. Methods: A VHH cDNA library was established by immunizing camels with PPRV vaccine, and the capacity and diversity of the library were examined. Four PPRV VHHs were selected, and the biological activity and antigen-binding capacity of the four VHHs were identified by western blot, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) analyses. ELISA was used to identify whether the four VHHs were specific for PPRV, and VHH neutralization tests were carried out. ELISA and western blot analyses were used to identify which PPRV protein was targeted by VHH2. Results: The PPRV cDNA library was constructed successfully. The library capacity was greater than 2.0 × 10⁶ cfu/mL, and the inserted fragment size was approximately 400 bp to 2000 bp. The average length of the cDNA library fragment was about 1000 bp, and the recombination rate was approximately 100%. Four single-domain antibody sequences were selected, and proteins expressed in the supernatant were obtained. The four VHHs were shown to have biological activity, close affinity to PPRV, and no cross-reaction with common sheep diseases. All four VHHs had neutralization activity, and VHH2 was specific to the PPRV M protein. Conclusions: The results of this preliminary research of PPRV VHHs showed that four screened VHH antibodies could be useful in future applications. This study provided new materials for inclusion in PPRV research.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1624-1641
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• 2015

Instantaneous relay (relay-without-delay) using interference alignment is a promising approach to neutralizing interference and improving system capacity. In Wang Chenwei's work, a 2-user scenario required both source and relay to access the global channel state information (CSI). This paper shows a new method of interference alignment improves the degrees of freedom (DoF) prominently for the 3-user MIMO interference channel with instantaneous relay. This new method is focused on the relay node that completes the alignment interference neutralization so the global CSI is obtained only once and the pressure on the base station can be mitigated. In addition, the 3-user MIMO interference channels with instantaneous relay can achieve 2M DoF when source and destination have M antennas, respectively. This method shows 33% improvement over the conventional method using interference alignment which obtains 3M/2 DoF.

• 한국동물위생학회지
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• 제37권2호
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• pp.97-100
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• 2014

This study was performed in Korea to get serological information for bovine herpesvirus 1 (BoHV-1), most commonly found in cattle. Antibodies against BoHV-1 were examined by targeting infectious bovine rhinotracheitis (IBR) in unvaccinated and vaccinated cattle, using viral neutralization (VN) test. In 2013, among 261 sera collected from IBR-unvaccinated herds, 7 sera (2.7%) were found seropositive and their VN titers were ranging from 1:4 to 1:32. Among 315 sera collected from IBR-vaccinated herds in large capacity farms, 303 sera (96.2%) were found to be seropositive for BoHV-1 and their VN titers were in the range of 1:4 to 1:2048. It was found that the IBR-vaccinated herds had higher levels of VN titer than IBR-unvaccinated herds. The results indicated that it may be due to heavy vaccination in vaccinated herds and no or a little infection in unvaccinated herds. At the end of the study it was concluded that although the seropositivity in IBR-unvaccinated herds was low, the monitoring of IBR should be continuously practiced to control and prevent the disease because of exportation of living cattle causing its nationwide outbreaks.

• Corrosion Science and Technology
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• 제8권3호
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• pp.110-115
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• 2009

At the onset of corrosion of steel in concrete, hydrogen ions usually evolve in the process of electrochemical reaction, thereby decreasing the pH of the pore solution, which can be buffered by cement hydration products, as being representatively illustrated by calcium hydroxide. Hence, a fall in the pH is dependent on properties of cement hydration (i.e. hydration products and degree of hydration). The present study tested acid neutralization capacity (ANC) of cementitious binders of OPC(Ordinary Portland Cement), 30% PFA(Pulverized Fuel Ash), 60% GGBS(Ground Granulated Blast Furnace Slag), 10% SF(Silica Fume) to quantify the resistance of cement matrix to a pH fall. Cement pastes were cast at 0.4 of a free W/C ratio with 1.5% chlorides by weight of binder in cast. Powder samples obtained crushed and ground specimen after 200 days of curing were diluted in still water combined with different levels of 1M nitric acid solution, ranging from 0.5 to 20 mol/kg. Then, the pH of diluted solution was monitored until any further change in the pH did not take place. It was seen that the pH of the diluted solution gradually decreased as the molar amount of nitric acid increased. At some particular values of the pH, however, a decrease in the pH was marginal, which can be expressed in the peak resistances to a pH fall in the ANC curve. The peaks occurred at the variations in the pH, depending on binder type, but commonly at about 12.5 in the pH, indicate a resistance of precipitated calcium hydroxide. The measurement of water soluble chloride at the end of test showed that the amount of free chloride was significantly increased at the pH corresponding to the peaks in the ANC curve, which may reflect the adsorption of hydration products to chlorides.

• 약학회지
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• 제33권2호
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• pp.111-117
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• 1989

The optimum reaction conditions for the acid consuming capacity of aluminum silicate synthesized from the reaction of sodium silicate solution and potassium aluminum sulfate solution were investigated by Box-Wilson experimental design, and the micromeritic properties were examined by the means of BET $N_2$ adsorption, Hg penetrometer and methylen blue adsorption. The chemical composition of the samples were analyzed by gravitic method. The results were found to be as follows: optimum reaction temperature $54.7^{\circ}C$, both concentrations of reactant soln 15.7%, reactants molar ratio (Al/Si) 0.5 and drying temperature $65.0^{\circ}C$. The acid consuming capacity of the sample prepared by above optimum conditions was 68 ml and the chemical composition was $Al_2O_3{\cdot}3.6SiO_2{\cdot}3H_2O$. The relationship between acid consuming capacity and micromeritic properties could not found in the range of experiments. Therefore, it is assumed that the acid consuming mechanism of aluminum silicate depends on the neutralization of $Al_2O_3$ and buffer action of $SiO_2$ in sample.

• 공업화학
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• 제7권4호
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• pp.698-706
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• 1996

메탄올로부터 HCHO를 생성하기 위하여 연속흐름 장치하에서 알칼리금속이 혼입된 여러가지 실리카-알루미나 촉매상에서 메탄올 탈수소반응을 수행하였다. HCHO의 생성은 촉매상의 Br${\ddot{o}}$nsted산보다는 Lewis산에 의존하였다. 이를 통해 메탄올의 탈수소촉매반응은 전자반응임을 알았고, 실리카-알루미나상의 Br${\ddot{o}}$nsted산은 알칼리금속의 혼입에 의해서 중화되었으며, Br${\ddot{o}}$nsted산의 중화효과는 혼입된 알칼리금속의 전자주게능력(electron-donating capacity)에 따라 다르게 나타났다. 그리고 메탄올 탈수소반응의 활성화에너지는 촉매의 Br${\ddot{o}}$nsted산점이 K에 의해 중화되었을 때 감소하는 경향을 보여주었다.

• 대한화학회지
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• 제63권6호
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• pp.486-504
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• 2019

본 연구에서는 2015 과학과 교육과정에 따른 통합과학, 화학 I, 화학 II의 '산·염기·중화반응', '산화·환원' 관련 성취기준과 교과서 활동 및 평가 문항을 과학과 핵심역량과 과학과 핵심역량별 하위요소를 기준으로 분석하였다. 통합과학의 성취기준에는 과학적 사고력이 가장 많이 포함되어 있었고, 과학적 탐구 능력, 과학적 의사소통 능력, 과학적 문제 해결력, 과학적 참여와 평생 학습 능력 순으로 5가지 과학과 핵심역량이 모두 포함되어 있었으나, 화학 I의 성취기준에는 과학적 사고력, 과학적 탐구 능력, 과학적 의사소통 능력이 포함되어 있었고, 화학 II의 성취기준에는 과학적 사고력만 포함되어 있었다. 통합과학, 화학 I, 화학II 교과서의 '산·염기·중화반응', '산화·환원' 활동에는 5가지 과학과 핵심역량이 모두 포함되어 있었고, 각 교과에서 과학적 탐구 능력과 과학적 사고력이 높은 비율로 포함되어 있었다. 통합과학, 화학 I, 화학 II 교과서의 '산·염기·중화반응', '산화·환원' 평가 문항에도 5가지 과학과 핵심역량이 모두 포함되어 있었으며, 각 교과에서 모두 과학적 사고력이 포함된 비율이 매우 높게 나타났다.

• 한국대기환경학회지
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• 제15권4호
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• pp.393-402
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• 1999

Precipitation samples were collected by the wet-only sampling method in Iksan in the northwest of Chonbuk from March 1995 to February 1997. These samples were analyzed for the concentration of ion components, in addition to pH and electrical conductivity. The annual mean pH of precipitation was 4.8 and the seasonal trend of pH was shown to be low in Fall and Winter(4.5), middle-ranged in Spring(4.7) and high in Summer(5.0). The frequency of pH below 5.6 was about 71%. The seasonal pattern of pH frequency was found to be different in each season. In the case of the pH less than 5.0, the frequency was higher in Spring, Fall and Winter than in Summer, especially higher in Fall than in other seasons. The concentrations of analysed ions showed a pronounced seasonal pattern. However, major ion species for all seasons were $NH^+_4,;Ca^{2+};and;Na^+$ among cations and $SO^{2-}_4,;Cl^-;and;NO^-_3$ among anions. The major acidifying species appeared to be $nss-SO^{2-}_4;and;NO^-_3$, and the main bases responsible for the neutralization of precipitation acidity were $nss-Ca^{2+};and;NH^+_4$. The potential acidity of precipitation, pAi, was found to be between 3.0 and 5.0 for total samples, while the measured pH was approximately between 3.9 and 7.8. The seasonal trend of pAi showed a decreasing order: Summer (4.3), Winter(4.0), Spring and Fall(3.8). During the Fall, both pAi and pH were especially very low, which indicated that during this period the potential acidity of precipitation was high but the neutralizing capacity was low. For Spring, pAi was very low but pH was slightly high. This was likely due to the large amount of $CaCO_3$ in the soil particles transported over a long range from the Chinese continent that were incorporated into the precipitation, and then neutralized the acidifying species with its high concentraton.

• 유기물자원화
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• 제7권1호
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• pp.13-21
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• 1999

본 연구에서는 폐기물의 재활용 측면에서 폐달걀껍질에 의한 중화능을 파악하는 동시에 중금속 제거 가능성을 고찰하였다. 폐달걀껍질 자체내에 Ca와 같은 알칼리성 성분으로 인하여 pH 상승효과가 탁월하며, 또한 폐수중의 중금속은 pH 상승으로 인하여 수산화물로 침전 제거되는 것으로 여겨진다. 폐달걀껍질은 응집 침전 및 흡착제로써 역할을 하기 때문에 주입량과 흡착질 농도에 영향을 받는 것으로 여겨진다. 흡착강도 1/n 값은0.35~0.44의 범위이며 Cu>Pb>Cr의 순으로 높게 나타났으나 흡착용량 k 값은 2.61~3.26의 범위이며 Pb>Cr>Cu의 순으로 높게 나타내었다.