석탄회를 이용한 미생물 고정화 세라믹 담체 제조

신대용,한상목,최신건,Shin, Dae-Yong,Han, Sang-Mok,Choi, Shin-Geon 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.9

석탄회와 벤토나이트 및 이스트 분말의 성형체를 800∼1,000$^{\circ}C$에서 1시간 소성하여 수질정화용 미생물 고정화 세라믹 담체를 제조하여 기공${\cdot}$기계적 특성을 조사하였다. 석탄회와 벤토나이트(FB)시편은 벤토나이트의 첨가량과 소성온도가 증가함에 따라 기공특성은 감소하였으나 압축강도는 증가하였다. 800∼1,000$^{\circ}C$에서 소성한 FB시편은 압축강도 89.6∼128.9 kgf/$cm^2$, 부피비중 1.25∼1.43, 겉보기비중 1.61∼1.78, 기공률 27.2∼62.2%, 평균기공경 7.9∼25.6${\mu}m$, 기공용적 8.9∼$22.2{\times}10^{-5}\;cm^3/g$ 및 비표면적 35.2∼134.3 $m^2/g$을 나타내었다. 이스트 분말을 첨가한 FBY시편은 FB시편에 비하여 기공특성이 향상되었으나 압축강도는 감소하였다. 9F1B시편에 10wt%의 이스트 분말을 첨가하여 900$^{\circ}C$에서 1시간 소성한 9F1B1Y시편은 압축강도 98.7 kgf/$cm^2$, 부피비중 1.20, 겉보기비중 1.67, 기공률 68.1%, 평균기공경 48.9 ${\mu}m$, 기공용적 $29.5{\times}10^{-5}\;cm^3/g$ 및 152.2 $m^2/g$의 비표면적을 나타내었으며, 담체의 기공에 S. saprophyticus의 부착특성이 양호하여 수질정화용 미생물 고정화 담체로 이용이 가능하였다. Porous ceramic supports with immobilized microorganisms for the water purifier were synthesized by firing green compacts of mixed powder comprising of fly ash, bentonite and an additive of yeast powder at 800∼1,000$^{\circ}C$ for 1h and the pore and mechanical properties of specimens were investigated. The compressive strength was increased in FB (Fly Ash + Bentonite) specimens while pore properties was decreased with increasing the bentonite content and sintering temperature. The compressive strength, bulk density, apparent density, porosity, mean pore size, pore volume and specific surface area of FB specimens at 800∼1,000$^{\circ}C$ were 89.6∼128.9 kgf/$cm^2$, 1.25∼1.43, 1.61∼1.78, 27.2∼62.2%, 7.9∼25.6 ${\mu}m$, 8.9∼$22.2{\times}10^{-5}\;cm^3/g$ and 35.2∼134.3 $m^2/g$, respectively. The pore properties of FBY (FB+yeast powder) specimens were superior to that of FB specimens, however compressive strength was decreased with increasing yeast powder content. The overall properties of 9F1B1Y (9F1B+10% of yeast powder) specimens at 900$^{\circ}C$ for 1 h were 98.7 kgf/$cm^2$, 1.20, 1.67, 68.1%, 48.9 ${\mu}m$, $29.5{\times}10^{-5}\;cm^3/g$ and 152.2 $m^2/g$, respectively. In this study, it was revealed that 9F1B1Y specimen demonstrated better S. saprophyticus adherence properties n their surface pores. Consequently, the microorganisms immobilized on porous ceramic supports showed better water purifying performance with many pores and adequate strength.

TiO₂ 코팅 석탄회 복합체의 기상 Acetaldehyde 광분해 특성

신대용,김경남,Shin, Dae-Yong,Kim, Kyung-Nam 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.1

The photocatalyst of $TiO_2$ coated on a fly ash composites (TCF) was prepared from precipitant dropping method to remove the acetaldehyde by photocatalytic reaction. The TCF were characterized by crystal aize, crystal structure and specific surface area. The photodegradation of acetaldehyde has been investigated using a UV-illuminated fixed photocatalytic reactor with TCF catalyst and P-25 catalyst in gas phase. The effect of photodegradation reaction conditions, such as initial concentration of acetaldehyde, concentration of oxidant in mixed gas and the light intensity on the photodegradation of acetaldehyde were investigated. P-25 catalyst showed the highest photodegradation of acetaldehyde and anatase $TiO_2$ coated TCF showed higher decomposition rate than rutile coated TCF. The photodegradation rate of acetaldehyde increased with the decrease of flow rate, initial concentration of acetaldehyde ($C_i$) and water vapor, however, it was increased with the increas of UV light intensity. The optimum conditions were weight of TCF=10 g, flow rate=50 ml/min $C_i$=100 ppm, concentration of oxygen=20%, concentration of water vapor=100 ppm.

옥외폭로시험 Tio₂ 코팅 세라믹 타일의 명도측정에 의한 방오특성 평가

신대용,김경남,Shin, Dae-Yong,Kim, Kyung-Nam 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.6

$TiO_2$ coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using $TiCl_4$ as a precursor. $TiO_2$ film was formed on the ceramic tile by spray-coating technique and heat-treated at $500^{\circ}C$ for 1 h. The size and crystalline structure of $TiO_2$ particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of $TiO_2$ on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of $TiO_2$ coating tile was affected by the coating amount of $TiO_2$ however, not affected by the UV light intensity included in sun's ray (irradiation direction). $TiO_2$ coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of $TiO_2$ coating tile.

인구정책의 효과의 시각적 확인을 위한 ABM 기반 인구추계모형 개발 연구

신대용 ( Shin Dae Yong ),김영훈 ( Kim Young Hoon ) 인구교육센터 2014 인구교육 Vol.7 No.-

본 연구에서는 인구정책의 효과를 가시적으로 확인할 수 있고, 기존 인구추계모형보다 실험조건 변환이 용이하며, 통계데이터를 제공할 수 있는 ABM 기반의 인구추계모형 프로세스를 구축, 이를 Netlogo 5.05를 이용하여 개발하였다. 이 연구를 통해 만들어진 인구추계모형은 출산율과 사망률, 인구이동률, 정책효과 등 몇 가지 변수만을 가지고 만들어졌지만, ‘피셔의 성비원리’도 구현되었으며, 인구정책효과가 수치적으로 계량화 된다는 가정하에 인구정책의 효과를 그래프와 모니터를 통해 가시적으로 확인하는 것이 가능하다. 그래프의 수치데이터를 제공하기 때문에 이를 다른 통계방법을 사용해 계량화를 하기에도 유용하다는 것 또한 장점이라 하겠다. In this study, we were to build and develop the demographic change models. The purpose of this study was to check the effect of population policy, to converse easily the experimental condition of policy effect than previous models, to provide statistical data using developed model. In order to achieve the above object, the model was built by using Netlogo 5.05. This model was developed using only four kinds of variables. They are fertility, mortality, population moving rate, policy effects. However, the model shows the effect of population policies visually using monitor and graphs. And Modelers can check the principles of “the Fisher’s sex ratio in this model. The developed model provides a numerical data on the graph and a histogram. So the modeler can easily analyze the data using a different statistical method.

수중에서 Sagnac 간섭계를 이용한 광섬유 센서의 지향성에 관한 연구

신대용(Dae-Yong Shin),권기태(Ki-Tae Kwon),이종길(Jongkil Lee),이준호(June-Ho Lee) 대한전기학회 2002 대한전기학회 학술대회 논문집 Vol.2002 No.7

비압축성 Navier-Stokes 방정식을 이용한 추력 편향 노즐 해석 (원통에서 사각형으로 변환하는 내부 흐름을 중심으로)

신대용(Dae-Yong Shin),윤용현(Yong-Hyun Yoon) 한국전산유체공학회 1997 한국전산유체공학회 학술대회논문집 Vol.1997 No.-

Circular-to-rectangular transition ducts are used as exhaust components of high performance fighter aircraft with vectored thrust nozzles. Three-dimensional incompressible Navier-Stokes solver is used to analyze the transition duct. Cross sections of transition duct are defined by superelliptic equation. The grid system is generated by Non-Uniform Rational B-Spline, after generating surface grid by blending the cross sections. Good agreement between the results of the computational simulation and the experimental data is observed.

Spinnability and rheological properties of sols derived from Si(OC₂H₅)₄ and Zr(O-nC₃H₇)₄solutions

신대용(SHIN DAE YONG),한상목(HAN SANG MOK) 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.1

The shape of the polymers in the mixed alkoxide solutions of Si(OC2H5)4 and Zr(n-OC3H7)4 with various water contents(1, 2, 4, and 8 in molar ratio to alkoxide, r) and catalysts was examined by rheological measurements, and is relation with fiber drawing behavior of the solutions was described. It was found that fibers could be drawn in the viscosity range 1~100 P from the acid-catalyzed solutions with lower water contents of the molar ratio H2O/alkoxide, r≤2. On the other hand, no fiber could be drawn from the acid-catalyzed solutions including a large amount of water(r≥4) and the base-catalyzed solutions. The relation between the intrinsic viscosity [η] and number average molecular weight Mn, namely [η] = KMnα, has shown that the acid-catalyzed spinnable solution (r = 1 and 2) had linear polymers where the exponent a’s were about 0.56 and 0.81, wheres non-spinnable solutions (r = 4 and 8) had three dimensional network polymers or spherical particles where the exponent a’s were 0.41-0.51 and 0.35.

졸-겔법으로 제조한 ZrO₂ㆍSiO₂계 결정화 유리의 결정화 및 파괴인성에 관한 연구

신대용(Shin Dae Yong),한상목(Han Sang Mok),강위수(Kang Wie -Soo) 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.1

Precursor gels with the composition of xZrO₂ㆍ(100-x)SiO₂ systems (x=10,20 and 30mol%) were prepared by the sol-gel method. Kinetic parameter, such as activation energy, Avrami’s exponent, n, and dimensionality crystal growth value, m, have been simultaneously calculated from the DTA data using Kissinger and Matusita equations. The crystallite size dependence on tetragonal to monoclinic transformation of ZrO₂ was investigated using XRD, in relation to the fracture toughness. The crystallization of tetragonal ZrO₂ occurred through 3-dimensional diffusion controlled growth(n=m=2) and the activation energy for crystallization was calculated using Kissinger and Matusita equations, as about 310~325±10kJ/mol. The growth of t-ZrO₂, in proportion to the cube of radius, increased with increasing heating temperature and heat-treatment time. It was suggested that the diffusion of Zr4+ions by Ostwald ripening was rate-limiting process for the growth of t-ZrO₂ crystallite size. The fracture toughness of xZrO₂ㆍ(100-x)SiO₂ systems glass ceramics increased with increasing crystallite size of t-ZrO₂. The fracture toughness of 30ZrO₂ㆍ70SiO₂ system glass ceramics heated at 1,100℃ for 5h was 4.84 MPam1/2 at a critical crystaliite size of 40 nm.

다구찌법을 이용한 저탄성 MRE 제조공정 연구

신대용(Dae-Yong Shin),자크리아 타리크(Zakria Tariq),라문우(Moon-Woo La),박성제(Sung-Jea Park) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.2

In this study, a PDMS-based low-elasticity magnetorheological elastomer (MRE) was fabricated and the Taguchi method was used to identify the factors affecting the elastic modulus. The mixing entropy was calculated using optical microscopy to confirm particle dispersion, which was referenced in the process establishment. In the MRE process, four parameters, namely the curing agent, particle type, particle fraction, and applied magnetic field, were divided into three levels. The elastic modulus of the specimen was compared at the off-state and at 0.2 T using compression tests, and the obtained signal to noise ratio indicated that the softness and change in the elastic modulus of the MRE was mainly affected by the curing agent and the particle fraction.

Region classification based on livestock vehicle movement data by community detection method

신대용(Dae-Yong Shin),박선일(Son-Il Pak),권교현(Kyohyun Kwon),김동현(Dong-Hyeon Kim),배선학(Sunhak Bae) 한국예방수의학회 2020 예방수의학회지 Vol.44 No.4

The purpose of this study is to obtain data on the zones formed by the movement of livestock vehicles and to determine if such areas can be used to establish quarantine activities and quarantine policies for livestock epidemics. For this purpose, this study used mobile data on poultry-related livestock vehicles generated in 2019. InfoMap, a community detection method, was used for regional classification, and the results of the analysis were visualized on a map using GIS. The study results confirmed that the zone of the administrative unit can be classified based on the movement of livestock vehicles. In addition, the zones created by the vehicle movement could be seen to change depending on the purpose and timing of the operation of livestock vehicles. Some areas form relatively stable zones, such as Jeolla-do and Gyeongsang-do, while others change depending on the situation, such as Chungcheong-do, Gyeonggi-do, and Gangwon-do. Further, the zones derived for poultry differed from those derived for cattle and pigs in previous studies.