목 적: 친수성 콘택트렌즈의 굴절력 측정 방식 중 하나인 Wet Cell 측정법에 대한 정확도를 확인하기 위 해 망원경식 렌즈미터를 사용하여 콘택트렌즈의 정점굴절력을 측정하였다. 방 법: Wet Cell 측정용 홀더는 현재 임상에서 주로 사용하고 있는 Poster Soft Contact Lens Wet Cell 제품을 사용하였으며, 국내 제조업체의 렌즈를 함수율은 38%, 45%, 58%로 구면굴절력은 -3.00D, -7.00D, -10.00D로 분류하여 각각 실험하였다. 결 과: 망원경식 렌즈미터를 사용하여 Wet Cell 방식으로 콘택트렌즈의 정점굴절력을 측정한 결과, -3.00D의 콘택트렌즈는 함수율 38%일 경우 -3.41D로 45%일 경우 –3.41D로 그리고 함수율 58%일 경우 -2.63D로 각각 측정되었다. -7.00D의 콘택트렌즈는 함수율 38%일 경우 –7.87D로 45%일 경우 –7.20D로 그리고 58%일 경우 -5.19D로 각각 측정되었다. 또한 -10.00D의 콘택트렌즈는 함수율 38%일 경우 –10.17D 로 45%일 경우 -10.60D로 58%일 경우 -7.33D로 각각 측정되었다. 결 론: 실험 결과, 함수율이 높을수록 Wet Cell 방식에 의한 측정값은 콘택트렌즈에 표기된 굴절력에 비 해 낮게 측정되는 경향을 나타내었다. 디옵터가 높아질수록 측정 정확도 역시 신뢰도가 낮은 것으로 나타났 다. Wet Cell 방식을 사용하여 망원경식 렌즈미터로 측정 시 함수율과 디옵터별로 정확도의 차이가 발생됨 을 알 수 있었다.

Spherical harmonics power spectrum of the geopotential field of Gaussian-bell type on the sphere was investigated using integral formula that is associated with Legendre polynomials. The geopotential field of Gaussian-bell type is defined as a function of sine of angular distance from the bell's center in order to guarantee the continuity on the global domain. Since the integral-formula associated with the Legendre polynomials was represented with infinite series of polynomial, an estimation method was developed to make the procedure computationally efficient while preserving the accuracy. The spherical harmonics power spectrum was shown to vary significantly depending on the scale parameter of the Gaussian bell. Due to the accurate procedure of the new method, the power (degree variance) spanning over orders that were far higher than machine roundoff was well explored. When the scale parameter (or width) of the Gaussian bell is large, the spectrum drops sharply with the total wavenumber. On the other hand, in case of small scale parameter the spectrum tends to be flat, showing very slow decaying with the total wavenumber. The accuracy of the new method was compared with theoretical values for various scale parameters. The new method was found advantageous over discrete numerical methods, such as Gaussian quadrature and Fourier method, in that it can produce the power spectrum with accuracy and computational efficiency for all range of total wavenumber. The results of present study help to determine the allowable maximum scale parameter of the geopotential field when a Gaussian-bell type is adopted as a localized function.

The W/O emulsion was formed by mixing hydrophobic nonion surfactants of span 80 and tween 60 with kerosine, and by adding sodium silicate aqueous solution. Precipitating the W/O emulsion by sodium bicarbonate resulted in spherical silica particles. Shape and size distribution of silica particles were observed. The particles were spherical and they have narrow size distribution. Particle sizes were 9.29, 7.39 and 5.73 μm at homogenizer speed of 2500, 3000, and 3500 rpm, respectively. The particle size was decreased by increasing agitation speed due to the formation of emulsion droplet. At fixed agitation speed, absorbed paraffin oil weight were measured and the SiO2/Na2O mole ratio effects on particle size were investigated. Particle size was decreased by increasing the mole ratio of SiO2/Na2O.

Almost half of primeval galaxies show P-Cygni type profiles in the Lyα emission line. The main underlying mechanism for the profile formation in these systems is thought to be the frequency re-distribution of the line photons in expanding scattering media surrounding the emission source. A Monte Carlo code is developed to investigate the Lyα line transfer in an optically thick and moving medium with a careful consideration of the scattering in the damping wings. Typical column densities and expansion velocities of neutral hydrogen investigated in this study are NH1 ~10 17-20 cm -2 and ΔV ~ 100 km s-1. We investigate the dependence of the emergent profiles on the kinematics and on the column density. Our numerical results are applied to show that the damped Lyα absorbers may possess an expanding H I supershell with bulk flow of ~ 200 km s-l and H I column density NH1 ~ 10 19 cm -2. We briefly discuss the observational implications.

Yogurt contains many microorganisms that are beneficial to human health, and is a probiotic that supplies many nutrients such as calcium and protein. It is difficult to safety preserve for a long time because it possesses a high content of water. To address this problem, powdered “instant” yogurt has been developed, but it has flaws low flowability and solubility. Therefore, yogurt was granulated using a fluidized bed granulator to increase flowability and solubility. The fluidized bed granulator was designed by using response surface methodology (RSM), whose variables were feeding rate (FR), atomization air pressure (AP) and product temperature (PT). After being granulated, the yogurt was analyzed for yield and lactic acid bacteria count. The maximum yield of yogurt granules was 79.42%, at FR of 0.54 mL/min, AP of 2.64 kPa, and PT of 58.18℃, and the colony count for lactic acid bacteria was more than 6 log10 CFU/g. Therefore, spherical granulation of yogurt using a fluidized bed granulator could be used for making convenient probiotic products with improved flowability and solubility.

최근 제설제의 영향으로 콘크리트에는 복합열화가 작용되어 도로시설물에 대한 2차 피해와 유지 보수 비용이 급격히 증가되고 있다. 그래서 실란, 실록산 계열의 흡수방지제를 사용하여 콘크리트 내부로 침투되는 수분 및 염화이온을 차단하는데 이용하고 있는 실정이다. 본 연구에서는 실란, 폴리실록산 계열의 흡수방지제가 갖는 단점을 개선하고자 이를 구형으로 제 조하여 콘크리트 강도별 침투깊이 및 동결융해저항 성능을 분석하였다.