• 약학회지
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• 제7권2_3호
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• pp.67-71
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• 1963

Studies the reaction mechanism and optimal reaction condition of the process of preparing sodium isocyanate, by means of heating of sodium carbonate and urea. Proposing, at the sametime, the quantitative analyzing method of sodium isocyanate in the presence of impurities of $Na_{2}CO_{3}$, urea and biuret. 1. Sodium isocyanate could be prepared by means of heating reaction of sodium carbonate and urea. 2. Adding urea into the heated sodium carbonate is reasonable. 3. Quantitative analysis of sodium isocyanate in the presence of impurities, $Na_{2}CO_{3}$, urea and biuret could be done by the following method:-adding nitrobarite solution into sample solution in order to remove $CO_{3}"$ and neutralize the solution, filtering off $BaCO_{3}$, and then precipitating isocyanate as a silver salt, filtering off AgNCO, and then, titrating remaining $AgNO_{3}$ with $NH_{4}SCN$, (indicator $FeNH_{4}(SO_{4})_{2})$/TEX>

• Corrosion Science and Technology
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• 제17권5호
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• pp.249-256
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• 2018

Metallic structures in the oil and gas production undergo severe degradation due to sweet and sour corrosion caused by the presence of $CO_2$ and $H_2S$ in the fluid environment. The corrosion behavior of 304 austenitic stainless was investigated in the presence of varying concentrations of $CO_2$ or $H_2S$ and $CO_2+H_2S$ to understand the effect of the parameters either individually or in combination. Potentiodynamic polarization study revealed that a small amount of $CO_2$ aided in the formation of calcareous deposit of protective layer on passive film of 304 steel, while increase in $CO_2$ concentration ruptured the layer resulting in sweet corrosion. The presence of $S^{2-}$ damaged the passive and protective layer of the steel and higher levels increased the degradation rate. Electrochemical impedance studies revealed lower polarization resistance and impedance at higher concentration of $CO_2$ or $H_2S$, supporting the outcomes of polarization study. XRD analysis revealed different types of iron carbides and iron sulphides corresponding to sweet and sour corrosion as the corrosion products, respectively. SEM analysis revealed the presence of uniform, localized and sulphide cracking in sour corrosion and general corrosion with protective carbide layer amid for sweet corrosion.

• Corrosion Science and Technology
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• 제7권1호
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• pp.22-26
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• 2008

Formation of protective iron carbonate films in $CO_2$ corrosion can reduce corrosion rate substantially and the effects have been incorporated in various prediction models. The $CO_2$ corrosion with the presence of free acetic acid is known to increase corrosion rate below scaling temperature. The possible interaction between the formation of iron acetate and iron carbonate films can affect the protectiveness of the film. The study is done using 3% NaCl solution under stagnant $CO_2$ -saturated condition at the scaling temperatures at various pH values and HAC concentrations. The result show that the presence of HAc does not affect the formation of protective iron carbonate film but delays the attainment of protective iron carbonate due to a possibility of solubilising of ferrous ions and thinning of the films.

• 자연과학논문집
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• 제4권
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• pp.95-102
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• 1991

규산삼석회$(C_3S)$의 수화반응에 있어서 $T1_2CO_3$의 농도변화에 따른 영향에 대해서 Isothermal microcalorimeter 등을 이용하여 조사한 결과, $T1_2CO_3$의 존재로 인하여 $C_3S$의 수화반응은 촉진되고 $C_3S$의 농도가 급격히 감소된다. 또 $T1_2CO_3$의 농도증가로 인해서 수화반응속도도 증가하고 있다. $T1_2CO_3$ 첨가에서 수화된 $C_3S$의 분석결과로는 반응초기에 $CaCO_3$가 나타나고 있으며, $T1_2CO_3$의 촉진작용이 수화반응의 초기에 있어서만 더욱 분명하게 나타나고 있음을 $C_3S$의 비휘발성 수분함량과 수화도로서 알수 있고 $C_3S$ paste와 접촉하고 있는 액상의 조성은 $T1_2CO_3$의 존재로 인하여 $Ca^(++)$이온과 $OH^-$ 이온의 농도가 상당히 변화하고 있음을 알 수 있다.

• 한국컴퓨터정보학회논문지
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• 제24권1호
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• pp.67-71
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• 2019

With continued technology innovation in the fields of computer graphics (CG) and virtual reality (VR), digital animated avatars (or virtual humans) are evolving into ones that are more interactive at a suitable location such as museum, airport, and shopping mall. Specially, the form of the avatar (or the virtual human) realistically need to be expressed in a way that matches the users' physical space. In recent many researches, the form of virtual human has been expressed as mixed-reality human (MRH)-the virtual human combines with the physicality as the real part. In this paper, we propose to carry out a study comparing various MRH on co-presence and emotional response in two-typed virtual humans depending on how many actual parts are included: (1) (Level 1) small parts in the virtual human combined virtual components (e.g., the head only) and (2) (Level 2) large parts in the virtual human with the physicality as the real part such as head, arms, and upper body). We report on the implemented results of our virtual humans and experimental results on co-presence and emotional response.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2003년도 하계학술대회
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• pp.223-225
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• 2003

Session Initiation Protocol(이하 SIP)은 H.323 network에서 제기된 문제점을 해결하고 다양한 multimedia service를 제공하기위해 IETF에서 정의된 protocol로서, 3GPP의 IP Multimedia Subsystem(이하 IMS)의 기반 protocol로 채택되었다. IMS는 multimedia service를 제공하기 위한 infrastructure로서 CSCF, HSS, MRF, MGCF, IM-GW등 기능적으로 분리된 여러 entity로 구성되며, 향후 추가될 다양한 부가 service에 유연하게 대처할 수 있는 Application Server(이하 AS) mechanism을 포함하고 있다. 현재 AS mechanism을 이용하여 3GPP규격 상에 정의된 대표적 서비스는 presence service이며, presence service network은 presence server, presence agent, presence proxy, watcher등으로 구성된다. 마지막으로 상기에 언급한 규격을 바탕으로 실제 구축된 Instant messaging/presence service network을 제시한다. (본문 참조)

• 멤브레인
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• 제23권4호
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• pp.290-296
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• 2013

촉매 1,8-diazabicyclo[5,4,0]undec-7-ene(DBU)를 이용하여, poly(vinylidenefluoride-co-chlorotrifluoroethylene) P(VDF-co-CTFE) 고분자와 methacrylic acid (MAA)를 반응시켜, P(VDF-co-CTFE)-MAA 공중합체를 제조하였다. 또한 P(VDF-co-CTFE)-MAA와 2-sulfoethyl methacrylate (SEMA) 단량체를 4',4'-azobis(4-cyanovaleric acid) (ACVA) 개시제 하에서 자유 라디칼 중합하여 수소 이온 전도성 막을 제조하였다. SEMA 함량이 많아짐에 따라 술폰산 그룹이 증가하였다. SEMA 함량이 50%일 때 최대 이온교환 용량값이 0.82 meq/g에 도달하였으며 이는 함수량 결과와 일치하였다. 또한, SEMA 함량이 50%일 때 수소이온 전도도가 0.041 S/cm까지 도달하였다. 이러한 결과는 분리막에서 SEMA 함량이 증가할수록 수소 이온을 전달시킬 수 있는 이온그룹이 증가하기 때문이다.

• Rapid Communication in Photoscience
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• 제4권3호
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• pp.67-69
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• 2015

FTIR spectroscopy has been employed to investigate the variation of anion-water hydrogen bonding in 1-butyl 3-methyl imidazolium tetrafluoroborate ([Bmim][$BF_4$]) ionic liquid caused by addition of organic co-solvents with various polarities. The variation was estimated by probing band shape and intensity of the OH stretching vibration of trace water present in ionic liquid at $3400-3800cm^{-1}$. The presence of polar aprotic co-solvent in ionic liquid dramatically reduces the absorptivity of the OH stretch band, indicating that the co-solvent changes the nature of anion-water hydrogen bond drastically, which might be responsible for the reduction of the viscosity of ionic liquid in the presence of the co-solvent.

• Journal of Veterinary Science
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• 제22권6호
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• pp.70.1-70.12
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• 2021

Bats are an important reservoir of several zoonotic diseases. However, the circulation of bat coronaviruses (BatCoV) in live animal markets in Indonesia has not been reported. Genetic characterization of BatCoV was performed by sequencing partial RdRp genes. Real-time polymerase chain reaction based on nucleocapsid protein (N) gene and Enzyme-linked immunosorbent assay against the N protein were conducted to detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and antibody, respectively. We identified the presence of BatCoV on Cynopterus brachyotis, Macroglossus minimus, and Rousettus amplexicaudatus. The results showed that the BatCoV included in this study are from an unclassified coronavirus group. Notably, SARS-CoV-2 viral RNA and antibodies were not detected in the sampled bats.

• BMB Reports
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• 제29권4호
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• pp.277-285
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• 1996

In Pseudomonas fluorescens grown on malonate as sole carbon source, acetyl-CoA synthetase was induced, suggesting that malonate is metabolized through acetate and then acetyl-CoA. Acetyl-CoA synthetase was purified 18.6-fold in 4 steps to apparent homogeneity. The native molecular mass of the enzyme estimated by a native acrylamide gel electrophoresis was 130 kDa. The enzyme was composed of two identical subunits with a molecular mass of 67 kDa. Optimum pH was 70. The acetyl-CoA synthetase showed typical Michaelis-Menten kinetics for the substrates, acetate, ATP and CoA, whose $K_m$ values were calculated to be 33.4, 74.8, and 40.7 mM respectively. Propionate. butyrate and pentanoate were also used as substrates by the enzyme, but the rate of the formation of the CoA derivatives was decreased in the order of the increase in carbon number. The enzyme was inhibited by the group-specific reagents diethylpyro-carbonate, 2,3-butanedione, pyridoxal-5'-phosphate and N-bromosuccinimide. In the presence of substrates the inactivation rate of the enzyme, by all of the group-specific reagents mentioned above decreased, indicating the presence of catalytically essential histidine, arginine, lysine and tryptophan residues at or near the active site. Preincubation of the enzyme with ATP, $Mg^{2+}$ resulted in the increase of its susceptibility to diethylpyrocarbonate, suggesting that ATP, $Mg^{2+}$ may induce a conformational change in the active site exposing the essential histidine residue to diethylpyrocarbonate. The enzyme was acetylated in the presence of acetyl-CoA, indicating that this is one of acyl-enzyme.