• 한국세라믹학회지
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• 제43권9호
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• pp.582-587
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• 2006

Decomposition behavior of $ferro-Si_3N_4$was investigated with varying temperature and holding time in mud components for high temperature refractory applications. Porosities gradually increased with increasing temperature and holding time due to the carbothermal reduction of $Si_3N_4\;and\;SiO_2$. Silicon monoxide (SiO) as a intermediate resulted from evaporation of $Si_3N_4\;and\;SiO_2$ reacted with C sources to generate needle-like ${\beta}-SiC$ and Fe in $Si_3N_4$ acted as a catalyst in order to enhance growth of SiC grain with the preferred orientation. SiC generation yield increased with increasing holding time, all of the $Si_3N_4\;and\;SiO_2$ affected on SiC formation up to 2h. However, SiC generation was only dependent on residual $SiO_2$ over 2h, because the carbothermal reduction reaction of $Si_3N_4$ was no longer possible at that time.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 동계학술발표회 논문집
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• pp.121-122
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• 2007

• 한국물환경학회지
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• 제28권3호
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• pp.401-408
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• 2012

High-voltage dielectric discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. The initiation and propagation of the electrical discharges depends on several physical, chemical, and electrical parameters such as 1st and 2nd voltage of power, gas supply, conductivity and pH. These parameters also influence the physical and chemical characteristics of the discharges, including the production of reactive species such as OH, $H_2O_2$ and $O_3$. The experimental results showed that the optimum 1st voltage and air flow rate for RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical) degradation were 160 V (2nd voltage of is 15 kV) and 4 L/min, respectively. As the increased of the 2nd voltage (4 kV to 15 kV), RNO degradation, $H_2O_2$ and $O_3$ generation were increased. The conductivity of the solution was not influencing the RNO degradation and $H_2O_2$ and $O_3$ generation. The effects pH was not high on RNO degradation. However, the lower pH and the conductivity, the higher $H_2O_2$ and $O_3$ generation were observed.

• 한국초등과학교육학회지:초등과학교육
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• 제25권2호
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• pp.159-166
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• 2006

Changes in the brain activities following pre-service elementary teachers' learning hypothesis-generation were investigated using the analysis of EEG relative power and EEG coherence. In this study, the experimental group (n=16) were trained using learning methods for hypothesis-generation and the control group(n=16) were trained using learning methods for hypothesis-reception over the course of 8 weeks. EEG was measured before and following the learning process for both groups. Decreased theta ($4{\sim}7.9Hz$)/alpha 1 ($8{\sim}9.9Hz$) power and increased alpha 2 ($10{\sim}l2.9Hz$)/beta ($13{\sim}29.9Hz$)/gamma ($30{\sim}50Hz$) power were showed in the experimental group. Additionally, many changes in brian activities were observed for theta, beta and gamma coherence in the experimental group. In particular, fronto-parietal coherence increased in the experimental group. These differences in brain activities between the two groups suggest that the learning for subjects' hypothesis generation presumably leads to interesting changes in some types of brain activities in pre-service elementary teachers.

• Macromolecular Research
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• 제16권2호
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• pp.113-119
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• 2008

A series of amphiphilic dendrons n-18 (n: generation number, 18: octadecyl chain) based on an aliphatic polyether denderitic core and octadecyl peripheries were synthesized using a convergent dendron synthesis consisting of a Williamson etherification and hydroboration/oxidation reactions. This study investigated their thermal and self-assembling behavior in the solid state using differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) absorption spectroscopy, and small angle X-ray scattering (SAXS). DSC indicated that the melting transition and the corresponding heat of the fusion of the octadecyl chain decreased with each generation. FT-IR showed that the hydroxyl focal groups were hydrogen-bonded with one another in the solid state. DSC and FT-IR indicated microphase-separation between the hydrophilic dendritic cores and hydrophobic octadecyl peripheries. SAXS data analysis in the solid state suggested that the lower-generation dendrons 1-18 and 2-18 self-assemble into lamellar structures based upon a bilayered packing of octadecyl peripheries. In contrast, the analyzed data of higher-generation dendron 3-18 is consistent with 2-D oblique columnar structures, which presumably consist of elliptical cross sections. The data obtained could be rationalized by microphase-separation between the hydrophilic dendritic core and hydrophobic octadecyl peripheries, and the degree of interfacial curvature associated with dendron generation.

• 대한임상검사과학회지
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• 제55권3호
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• pp.203-212
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• 2023

코로나19가 창궐한 후 임상병리사(medical technologists, MT)가 병원에서 PCR 검사를 수행하고 있을 뿐만 아니라 차세대 염기서열분석(next-generation sequencing, NGS)도 수행한다는 사실을 일반적으로 알고 있다. 하지만, 많은 사람들은 유전자검사 분야에 대한 임상병리사의 업무로 의료법에 명시되어 있지 않다는 사실을 인지하지 못하고 있는 실태이다(MT 72.5%, N=200; 학생 62.8%, N=123). 이러한 이유로, NGS에 대한 임상병리사의 업무 적절성을 검증하기 위해서 온라인 설문지를 작성하도록 설계하여 설문조사 결과를 분석하였다. NGS가 포함된 유전분야에 대한 임상병리사의 업무범위에 대한 법제화가 필요하다(MT 99.5%, N=200, 학생 86.8%, N=123)고 나타났다. 그리고 임상병리사 국가면허시험 문제은행에 세포유전학 및 분자유전학 관련 임상유전학 문항이 모두 포함돼야 한다(MT 97.5%, N=200; 학생 72.3%, N=123)고 조사되었다. 이러한 조사를 바탕으로 임상병리학 분야의 발전을 위해 임상병리사와 학생 모두를 위한 유전자 교육 및 법제화를 위해 대한임상병리사협회는 교수협의회와 적극 협력할 필요가 있겠다.

• 한국동물위생학회지
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• 제45권1호
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• 유기물자원화
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• 제10권1호
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• pp.102-108
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• 2002

The effects of ammonia on mesophilic anaerobic digestion were investigated by operating lab-scale two-stage ASBF reactors using swine wastewaters as influent without and with ammonia removal at HRT of 1-2 days and OLR of $2.2{\sim}9.6kg-COD/m^3{\cdot}d$ for 250 days. The COD removal efficiency and biogas generation of two-stage ASBF reactors was decreased by increasing influent ammonia concentrations to 1,580 mg(T-N)/L with increasing OLR to $6.3kg-COD/m^3{\cdot}d$, while those were increased by maintaining influent ammonia concentrations below 340 mg(T-N)/L by MAP precipitation with increasing OLR to $9.6kg-COD/m^3{\cdot}d$. Initial inhibirion of ammonia on anaerobic processes was observed at a concentration of 760 mg(T-N)/L and the COD removal efficiency and biogas generation dropped to 1/2 at ammonia concentration ranges of 1,540~1,870 mg(T-N)/L. It is essential to remove ammonia in swine wastewaters to an initial inhibition level before anaerobic processes for the effective removal of COD.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.30-32
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• 2005

Internet의 확대와 망의 진화에 따라 현 통신 방식은 기존 회선 교환 방식에서 패킷 교환 방식으로 진화를 한다. NGN(Next Generation Network)이란 정확하게 정의를 내리기는 어렵지만, 개념적으로는 현존하는 모든 서비스(Voice, Data, Video 등)들과 미래에 나타날 멀티 서비스를 통합하여 수용할 수 있는 패킷 기반의 통신망을 의미한다. 이러한 개념은 망의 통합을 목적으로 하는 BcN(Broadband Convergence Network, 이하 BcN)로 진화하고 있다. 하지만, 진정한 의미의 BcN은 Legacy 회선 교환 방식(include Wireless Network)과 패킷 교환 방식의 모든 망 사용자에게 동일한 서비스를 제공하는 것이며, 이것은 Convergence Service라는 개념으로 정리를 할 수 있다. 본 논문에서는 이와 같은 접근을 Next Generation Convergence Service(이하 NGcS)로 정의를 한다. 논문에서는 NGcS 구축을 위해 지능망 서비스와 연계하여 접근을 할 것이며, INAP(Intelligent Network Application Protocol), WIN(Wireless Intelligent Network) 및 CAP(CAMEL Application Part) 등의 제어방식에 근거한다. 이러한 방식들에 대한 연동에 대해 논하며, NGcS 구축을 위한 Service Switching Function 설계 방법과 서비스를 트리거(Trigger)하기 위한 방법에 대해 논한다.

• Animal Bioscience
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• 제34권7호
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• pp.1116-1122
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• 2021

Objective: The aim was to characterize the genetic diversity evolution of the registered Mexican Charolais cattle population by pedigree analysis. Methods: Data consisted of 331,390 pedigree records of animals born from 1934 to 2018. Average complete generation equivalent, generation interval, effective population size (N_e), and effective numbers of founders (f_e), ancestors (f_a), and founder genomes (N_g) were calculated for seven five-year periods. The inbreeding coefficient was calculated per year of birth, from 1984 to 2018, whereas the gene contribution of the most influential ancestors was calculated for the latter period. Results: Average complete generation equivalent consistently increased across periods, from 4.76, for the first period (1984 through 1988), to 7.86, for the last period (2014 through 2018). The inbreeding coefficient showed a relative steadiness across the last seventeen years, oscillating from 0.0110 to 0.0145. During the last period, the average generation interval for the father-offspring pathways was nearly 1 yr. longer than that of the mother-offspring pathways. The effective population size increased steadily since 1984 (105.0) and until 2013 (237.1), but showed a minor decline from 2013 to 2018 (233.2). The population displayed an increase in the f_a since 1984 and until 2008; however, showed a small decrease during the last decade. The effective number of founder genomes increased from 1984 to 2003, but revealed loss of genetic variability during the last fifteen years (from 136.4 to 127.7). The f_a:f_e ratio suggests that the genetic diversity loss was partially caused by formation of genetic bottlenecks in the pedigree; in addition, the N_g:f_a ratio indicates loss of founder alleles due to genetic drift. The most influential ancestor explained 1.8% of the total genetic variability in the progeny born from 2014 to 2018. Conclusion: Inbreeding, N_e, f_a, and N_g are rather beyond critical levels; therefore, the current genetic status of the population is not at risk.