본 논문에서는 다기능성 마스크 팩의 제조 및 이를 이용한 마스크 팩 제조 및 평가에 대한 것이다. 여기서 다 기능성이란 폴리인산에 의한 원적외선 효과, 포접화합물에 의한 기미치료 효과 및 필링효과, 라벤다 추출물에 의한 피부진정 효과를 의미한다. 제조한 다기능성 마스크 팩의 용제에 대한 유해물질의 측정결과 0.001mg/Kg 이하로 검출되었으며, 점도는 280 cP, pH=6.92 이었다. 마스크 시트에 다기능성 용제를 침지시켜 제조한 다기능성 마스크 팩의 원적외선 방사율은 0.882 μm이고 원적외선 방사에너지는 3.40x102 W/mᆞ, 37℃이었다. 다기능성 마스크 팩의 착용 후, 5일간 사용 후의 보습율은 사용전보다 14.5% ~ 35.5% 우수하였으며, 피부 온도는 24 ~ 26℃ 나타내었으며, 30명의 볼란티어 피부접촉 자극성 평가에서도 매우 안정적이었다.

PURPOSES : This study establishes a pay adjustment factor scheme that will penalize or provide incentives to contractors after pavement construction in Seoul City. METHODS: Random sampling was conducted, wherein acceptable quality characteristics (AQCs) of the field mixture such as the aggregate gradation, asphalt binder content, pavement thickness, field air void, and IRI (International Roughness Index) were determined. Using the acquired field data, the percent within limit (PWL) values of each AQC were determined. RESULTS : Weight factors were used to consider the effect of each AQC, since field data varies depending on the field condition. The total pay factor (PF) was determined by combining the PF material and PF construction. PF material considers the asphalt binder content and the aggregate gradation, while PF construction considers the field air void, pavement thickness, and field IRI. CONCLUSIONS: A pay adjustment factor was established by determining the PWL of each AQC and calculating the corresponding pay factor. Based on the results, it is found that PWL is a reasonable and acceptable method for evaluating the pavement quality and determining the pay factor.

PURPOSES : Recently, there has been an increase in the use of discrete randomly distributed fiber materials for reinforcing pavement foundations. However, very limited study has been made on this from the perspective of pavement engineering. Therefore, this study evaluates the performance of soil-geofibers used in pavement foundations as well as the effects of stress dependency with various mixtures. METHODS: To estimate the behavior of soil-geofiber mixtures under traffic loadings, laboratory resilient modulus data for the mechanical characteristics of geofiber mixtures were used, and they were adopted to evaluate the structural response and analyze the stress dependency through 2-D finite element analysis. As the host materials, poorly graded and uniformly graded sand were selected, and each soil was mixed with three different types of fiber, namely monofilament, fibrillated, and tape. RESULTS: The stress dependent response on resilient modulus and Poisson’s ratio were mainly considered by conducting linear and nonlinear elastic analyses on various geofiber mixtures. As a result, it was found that the response and yield function of geofiber mixed layers in pavements were affected considerably depending on the gradation of the soils and the confinement conditions. A small change was found when the particle size was homogenized. CONCLUSIONS : From this, it can be concluded that the finite element model with stress dependency is suitable for estimating the performance on geofiber mixtures. It is also noted that all the responses of geofiber mixtures were relatively sensitive to the gradation of host soils. This indicates that the effects of the nonlinearity and stress-dependency of geofiber mixtures under repetitive loadings could be substantial.

엘크 수사슴의 체중 성장곡선 및 일당증체량을 추정하기 위하여 국립축산과학원 가축유전자원센터에서 사육중인 엘크 수사슴 183두의 체중-일령 자료 1,509개에 대해 비선형 회귀식인 Gompertz와 Logistic 모형을 적용하였다. 추정된 엘크 수사슴 성장곡선 모수인 성숙체중(A), 성장비율(b)과 성숙률(ｋ)은 Gompertz 모형의 경우 각각 335.5±1.415kg, 2.18±0.045와 0.0025±0.00005였고, Logistic 모형에서는 330.5±1.337kg, 5.46±0.209와 0.0355±0.00009였다. 적합도 검정을 위한 결정계수(R2)는 두 모형에서 큰 차이가 없어 두 모형 다 적합한 것으로 나타났다. 다만, 실제 측정값과 추정값에 대한 차이인 평균제곱근 오차 값이 엘크 암사슴에 비해 크게 나타났으며 따라서 엘크 수사슴의 낙각 및 번식기 체중 증감을 고려한 성장곡선 모형에 대한 추가적인 연구가 필요할 것으로 판단된다. 엘크 수사슴에서 Gompertz 모형으로 추정된 함수식은 f(t)=335.5Xe^-2.18e^-0.0025t였고, Logistic 모형의 경우 F(t)=330.5X(1+5.465e^-0.00355t)^-1였다. 각 모형에서 제1차 도함수로 유래된 일당증체량 곡선은 Gompertz 모형의 경우 F'(t)=0.0025Xf(t)X1n(335.5/f(t)), Logistic 모형의 경우f'(t)=0.0036Xf(t)X[1-f(t)/330.5]였다. 이 함수식을 통해 도출된 엘크 수사슴에서 최대 증체량을 나타내는 시기인 315~478.3일령, 123.4~165.3㎏ 도달 전후에는 보다 세심한 사양관리가 필요할 것으로 보인다. 본 연구에서 도출된 엘크 수사슴의 성장곡선 모수 추정값, 변곡점 및 변곡점 도달일령 등은 사슴산업 종사자들이 사양관리 및 육종계획을 수립하는 데에 도움이 될 수 있을 것으로 사료된다.

We prepared Y3Al5O12;Ce3+,Pr3+ transparent ceramic phosphor using a solid state reaction method. By XRD pattern analysis and SEM measurement, our phosphors reveal an Ia-3d(230) space group of cubic structure, and the transparent ceramic phosphor has a polycrystal state with some internal cracks and pores. In the Raman scattering measurement with an increasing temperature, lattice vibrations of the transparent ceramic phosphor decrease due to its more perfect crystal structure and symmetry. Thus, low phonon generation is possible at high temperature. Optical properties of the transparent ceramic phosphor have broader excitation spectra due to a large internal reflection. There is a wide emission band from the green to yellow region, and the red color emission between 610 nm and 640 nm is also observed. The red-yellow phosphor optical characteristics enable a high Color Rendering Index (CRI) in combination with blue emitting LED or LD. Due to its good thermal properties of low phonon generation at high temperature and a wide emission range for high CRI characteristics, the transparent ceramic phosphor is shown to be a good candidate for high power solid state white lighting.

Glass wool is widely used as a typical soundproofing material because it has superior characteristics as a soundproofing material as well as excellent marketability. However, moisture penetration through condensation and cleaning up causes deterioration of insulation and soundproofing performance. In this study, we evaluate the wettability and sound absorption performance when the metal is deposited on the surface of glass wool. The performance is examined based on parameters such as the angle test, drying speed, the absorbency, the moisture content, the wettability. The wettability data shows that Cu coated glass wool is the best performance compaed to Ti coated one. The sound insulation characteristics are also compared by using the impedance tube. At the low frequency range, there is no difference among the test specimens, however, at the frequency above the 250 Hz range, Cu coating shows 10 % better in th sound asorption. Ti coating has almost same to the existing glasss wool performance. It turns out that metal coating on the glass wool seems to be very promising: the metal deposition reveals strong water repellency and sound absorption performance is equivalent to the existing glass wool.

Glass wool is a fiber made by melting sand and waste glass at high temperature. It has been used as an inorganic fiber for sound absorption, insulation, and non-combustible materials for automobiles, ships, and household appliances. However, the disadvantage comes from the moisture penetration through condensation and cleaning up so that it deteriorates insulation and soundproofing performance. In order to overcome the disadvantages of glass wool, we investigate the water repellency by plating metal on the surface of glass wool with Cu and Ti while coating stability is considered. The thickness of the deposited metal is about 300 nm. The deposition chemicals and the image of the specimen are analyzed by using SEM equipment. The electron microscopic result shows that quite amount of Cu and Ti metals are deposited on the glass wool surface.

Severe wall thinning is found on the tube of a low-pressure evaporator(LPEVA) module that is used for a heat recovery steam generator(HRSG) of a district heating system. Since wall thinning can lead to sudden failure or accidents that lead to shutdown of the operation, it is very important to investigate the main mechanism of the wall thinning. In this study, corrosion analysis associated with a typical flow-accelerated corrosion(FAC) is performed using the corroded tube connected to an upper header of the LPEVA. To investigate factors triggering the FAC, the morphology, composition, and phase of the corroded product of the tube are examined using optical microscopy, scanning electron microscopy combined with energy dispersive spectroscopy, and x-ray diffraction. The results show that the thinnest part of the tube is in the region where gas directly contacts, revealing the typical orange peel type of morphology frequently found in the FAC. The discovery of oxide scales containing phosphate indicates that phosphate corrosion is the main mechanism that weakens the stability of the protective magnetite film and the FAC accelerates the corrosion by generating the orange peel type of morphology.

본 연구에서는 발아와 고압처리에 따른 검정콩 조사포닌 추출물의 in-vitro 항암 활성을 확인하기 위하여 검정콩을 발아시킨 후 고압처리하고, 조사포닌 추출물을 제조한 후 인체 유래 유방암(MCF-7), 대장암(HCT-116), 전립선암(PC-3) 및 위암(AGS) 세포주에 대한 증식억제효과를 검토하였다. 대조구의 조사포닌 추출물은 400 μg/mL 농도에서 4종의 암세포주에 대하여 67.02~91.70% 범위의 생존율을 보여 항암 효과가 낮았지만, 발아 4일차 콩을 150 MPa의 압력에서 고압처리한 검정콩의 조사포닌 추출물은 23.94~57.37% 범위의 생존율을 보여 발아와 고압처리에 의해 암세포 성정억제효과가 증가하였다. 특히, 위암세포(AGS)의 경우 다른 세포주에 비해 저농도에서도 세포증식효과를 보여 가장 높은 암세포 증식억제 효과를 나타내었다. 이상의 결과로부터 항암 활성을 나타내는 Soyasaponin, B group의 soyasaponin 및 soyasapogenol의 함량은 발아와 고압처리에 의해 증가하였고, 고압처리 발아콩으로부터 항암 활성을 나타내는 사포닌 추출물의 개발이 가능할 것으로 생각된다. 또한, 추후 항암 활성 물질의 분리동정과 메커니즘 규명에 대한 연구가 수행되어야 할 것으로 판단된다.

본 연구는 2017년 국내에서 유통되는 유산균을 함유한 건강기능식품과 가공식품 120건에 대하여 프로바이오틱스 함량, pH와 산도를 분석하였다. 또한, 건강기능식품 중 프로바이오틱스 5개 제품에 대한 보존방법에 따른 변화를 조사하였다. 프로바이오틱스 제품 85건 중 2건이 표시량 이하였고, 가공식품 35건은 모두 적합이었다. 프로바이오틱스 제품의 프로바이오틱스수, pH, 산도 평균은 각각 1.2 × 1010 CFU/g (표시량: 3.4 × 109 CFU/g), 5.35, 1.29%이었으며, 가공식품 중 유산균 함유량 표시 식품 17건의 유산균수 평균은 5.8 × 108 CFU/g이었다. 프로바이오틱스 5제품의 보존온도(−20℃, 4℃, 20℃, 40℃)와 보존기간(1, 3, 6개월) 경과에 따른 프로바이오틱스 함량 변화를 관찰한 결과, 보존기간 1개월에서 6개월 후 프로바이오틱스수 감소율은 평균 59%이었고, 4℃에서 가장 낮은 감소율과 40℃에서 가장 높은 감소율을 나타내었다. 또한, 5개 제품 중 3제품에서 보존기간 1개월에서 3개월 경과 후 40℃에서 70%이상 급격한 균수 감소를 관찰할 수 있었다. 따라서 프로바이오틱스 제품의 보존온도와 보관기간에 따른 변화를 고려할 때 프로바이오틱스 제품은 냉장보관을 권장하며 구입 후 되도록 단기간에 섭취하는 것이 바람직한 것으로 판단된다.