• 비파괴검사학회지
• /
• 제18권2호
• /
• pp.85-91
• /
• 1998

핵연료 제작과정에서 봉단마개 용접부는 완벽한 품질이 요구되고 있다. 본 연구에서는 와전류탐상방법을 이용하여 봉단마개 용접부의 검사를 위한 기초적인 방법을 연구하였다. 봉단마개 용접부 와전류검사를 위한 주사속도와 와전류신호의 최대주파수를 찾았고 잡음신호제거를 위해 대역통과여파기(0-250Hz)론 사용하였다. 이러한 와전류탐상방법은 직경 0.35mm의 작은 핀홀결함에서도 좋은 감도를 얻을 수 있었다.

• ETRI Journal
• /
• 제32권2호
• /
• pp.265-272
• /
• 2010

To supply a power distribution network with stable power in a high-speed mixed mode system, simultaneous switching noise caused at the multilayer PCB and package structures needs to be sufficiently suppressed. The uni-planar compact electromagnetic bandgap (UC-EBG) structure is well known as a promising solution to suppress the power noise and isolate noise-sensitive analog/RF circuits from a noisy digital circuit. However, a typical UC-EBG structure has several severe problems, such as a limitation in the stop band's lower cutoff frequency and signal quality degradation. To make up for the defects of a conventional EBG structure, a partially located EBG structure with decoupling capacitors is proposed in this paper as a means of both suppressing the power noise propagation and minimizing the effects of the perforated reference plane on the signal quality. The proposed structure is validated and investigated through simulation and measurement in both frequency and time domains.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
• /
• pp.94-97
• /
• 2006

Timber stand age information of timber in industrialized plantation forest is generally collected by field surveying which is labor-intensive, time-consuming, and very costly. It is also inconsistent in analyses perspective. As an alternative, The objective of this research is to present a practical solution for estimating timber age of loblolly pine plantation using Landsat thematic mapper (TM) images, shuttle radar topography mission (SRTM), and national elevation dataset (NED). A multivariate regression model was developed based upon satellite image-based information (i.e.normalized difference vegetation index (NDVI), tasseled cap (TC) transformation, and derived tree heights). A residual studentized technique was applied to remove potential outliers. After that, a refined age estimation model with a correlation coefficient R-square of 84.6% was obtained. Finally, the feasibility test of estimated model was performed by comparing estimated and measured stand ages of timber plantations using test datasets of plantation stands (2,032 stands). The result shows that the proposed method of this study can estimate loblolly pine stand age within an error of $2{\sim}3$ years in an effective and consistent way in terms of time and cost.

• 환경위생공학
• /
• 제23권3호
• /
• pp.39-46
• /
• 2008

In order to study the estimate of $CH_4$ emission factors in the municipal wastewater treatment plants, the active sludge process, 5-stage process, Denipho process, and SBR process were investigated. When active sludge process, 5-stage process, and Denipho process were used in wastewater treatment plant, the $CH_4$ emission factors were 2.88, 1.61, and 0.57 g-$CH_4/kg$-BOD, respectively. On the other hand, in the case of SBR process, it was 4.14 g-$CH_4/kg$-BOD. These results indicate that SBR process was effective for $CH_4$ emission in municipal wastewater treatment plants. Using the above processes, the methane emission factor and amount of waste water sludge were $4.78m^3/t$ and $12,204,506m^3/yr$, respectively. The remove of BOD was a range of $93.91{\sim}98.63%$.

• 한국초전도ㆍ저온공학회논문지
• /
• 제9권4호
• /
• pp.24-27
• /
• 2007

The purpose of this work is to develop, integrate, and implement an optical characterization method to evaluate physical properties in coated conductors and investigate the local distribution of the causes of degraded performance. The method that we selected at this moment is Raman scattering spectroscopy, which is accompanied with measurements of local supercurrent transport, phase composition, microstructure, and epitaxy quality for coated conductors that range in size up to multi-meter-length tapes and that embrace the entire tape embodiment (substrate through cap layer). The establishment of Raman spectroscopy as an on-line process monitoring tool is our eventual goal of research, but it requires very robust and cost-effective equipments. We analyzed $YBa_2Cu_3O_7(YBCO)$ thin films grown at various substrate temperatures by using Raman spectroscopy. YBCO films were grown by a high-rate electron-beam co-evaporation method. Raman spectra of YBCO films with lower-transport properties exhibit additional phonon modes at ${\sim}300cm^{-1}$, ${\sim}600cm^{-1}$ and ${\sim}630cm^{-1}$, which are related to second-phases such as $Ba_2Cu_3O_{5.9}$ and $BaCuO_2$. We propose a new method to characterize Raman spectra of coated conductors for an in-line quality control.

• Mycobiology
• /
• 제38권4호
• /
• pp.249-255
• /
• 2010

We identified Lacrymaria velutina of the Coprinaceae in Korea. The unusually large and sturdy fruiting body, fibrillose to fibrillose-scaly cap and stalk without a volva with an obscure superior hairy ring zone or hairy annulus, and blackish brown, warted spores distinguished this species from closely related Psathyrella species. An illustrated account of the microscopic traits is presented. Fruiting bodies with obtusely hemispherical caps, 2.5~6 cm, becoming convex with age; surface dry, densely fibrillose-scaly with split margin; stipe, 4.5~6 cm, equal, hollow, fibrillose, dry, whitish above the superior ring zone, light brown below; crowded gills, adnexed, dark black at maturity. Pileipellis typically cellular with the gill edge appearing white and beaded. Blackish brown basidiospores that discolor in concentrated sulfuric acid. Spores elliptical, warted, $9\sim11{\times}6\sim8{\mu}m$, with prominent snout-like germpores. Cheilocystidia abundant, $57\sim68{\times}19\sim25{\mu}m$, and narrowly elongated clavate, often clustered in threes or fours. Pleurocystidia rarely present, $45\sim47.5{\times}12\sim13{\mu}m$, and clavate to utriform. This trait distinguishes our sample as L. velutina from other Psathyrella spp. of the Coprinaceae, which have smooth spores. This taxon was clarified by the observation that Psathyrella spores fade in concentrated sulfuric acid. A molecular phylogenetic study revealed that our specimen was Lacrymria velutipes, which is closely related to Lacrymaria lacrymabunda. Moreover, those two species are clearly distinguishable from other Psathyrella species, which agreed with the morphologically distinctive traits described above. We believe that this is the first report of this taxon, which has not been described in Korea.

• 한국포장학회지
• /
• 제12권1호
• /
• pp.63-73
• /
• 2006

한국의 시유 포장은 1937년 7월부터 현재 서울우유협동조합(그 당시 경성우유동업조합)이 1홉(hob : 180 ml, 0.048 standard gallon) 유리병에 지전(paper cap) 또는 콜크마개(cork cap)로 사용한 것이 최초였다. 그 이후(1945$\sim$1972)로 2홉 유리병 360 ml도 생산되었고 마개도 철전(iron cap)이나 plastic film을 씌운 뚜겅이 관모(egret, pappus)형태로 바뀌었다. 그 밖에 우유병이 부족하면 사이다병, 맥주병 등 유색유리용기가 사용되기도 하였다. 우유생산업체는 한국에서 서울우유협동조합만이 유일하게 있다가 1964년 3월 남양유업(주)이 창립되고, 1969년 현재 해태유업(그 당시 대한식품공사)이 설립, 1971년 5월 현재 매일유업(주)(그 당시 한국낙농유업) 등 여러 업체들이 점진적으로 설립되어 각 종의 낙농제품(dairy products, dairy manufactures)이 포장되어 생산되기 시작하였다. 그리고 1971년에 서울우유협동조합에서 처음으로 삼각형 폴리 에틸렌필름용기가 사용되었고 1972년에는 남양유업(주)의 종이용기인 Tetra pak 멸균팩을 수입하여 최초 사용하였다. 1974년경부터 사각형 폴리에틸렌필름포장과 플라스틱병 용기가 처음 선보였으며, 1977년에는 종이포장인 게이블톱 카튼팩(gable top carton pack)이 서주산업(주)에 의해 최초로 소개된 후 급격히 시장점유율이 확대되었고 용량에서도 180 ml에서 200 ml, 250 ml, 500 ml, 1,000 ml의 대형으로 서서히 바뀌었으며 그에 맞춰 소비량도 변화되었다. 그리고 파스퇴르 우유 490 ml의 포장을 1987년 9월에 국내 최초로 몸체는 고밀도 폴리에틸렌병(high density polyethylene bottle), 뚜껑은 저밀도 폴리에틸렌을 사용하였고 1992년 7월 남양유업은 다우(DOW)란 상품명으로 polyethylene병에 235g, 450g, 930g을 넣어 4각형 형태로는 최초 시판하였다.

• 한국대기환경학회지
• /
• 제22권6호
• /
• pp.791-798
• /
• 2006

In order to investigate the NVOC (Natural Volatile Organic Compound) emissions from White Oak, the emission rates of isoprene were measured according to season, weather conditions, and the age of the tree. The analysis of seasonal emission rates showed that the emission rates were the highest during summer followed by spring and fall. The emission rates during summer were found to be nearly 8 times greater than those during fall. In addition, it was observed that the emission rates of isoprene depends on PAR and temperature. Moreover, the effect of age on the emission rates was studied, and the White Oak in the age range of $21{\sim}30$ had higher emission rates than that in the range of $41{\sim}50$. Accordingly, the current result indicates that the isoprene emissions are affected by both meteorological parameter and the age of a tree.

• 한국태양에너지학회 논문집
• /
• 제25권4호
• /
• pp.69-76
• /
• 2005

The performance of water-to-water heat pump system coupled with the ground source vertical heat exchanger is presented in this paper. The CAP program of Florida Heat Pump Co. is used to predict the heat pump performances while the EED program calculates the borehole fluid temperature. It is shown that COPH increases with decreasing the temperature of output water for the operation of heating mode and COPR increases with increasing temperature of output water for the operation of cooling mode. The value of specific heat extraction rate must be moderate to insure the reasonable installation cost of borehole system. With $1^{\circ}C$decrease of $T_{wo}$ the average COPH increase is estimated as about $0.06/^{\circ}C$(for $T_{wo}\;=\;45{\sim}60^{\circ}C$ range) while with $1^{\circ}C$ increase of $T_{wo}$ the estimation of COPR increase is about $0.13/^{\circ}C$(for $T_{wo}\;= \;5{\sim}11^{\circ}C$ range) at the specific heat extraction rate of 30W/m.

• 한국균학회지
• /
• 제27권3호통권90호
• /
• pp.231-233
• /
• 1999

In the present paper, a new variety of Cordyceps gunnii (Berk.) Berk. is reported. It differs from C. gunnii by its much smaller secondary ascospores, (2.0-) 3.3 $(-4.3){\times}1.0{\sim}1.8\;{\mu}m$, as well as thinner asci and cap of the asci. Its anamorph is also reported as a new variety of Paecilomyces gunnii Liang, the ansmorph of C. gunnii. Its differ from P. gunnii by its conidia, mostly subglobose and much bigger, (2.2-) 4.7 $(-11.0){\times}(1.8-)\;2.6\;(-3.3)\;{\mu}m$. The type specimen and dry type culture are deposited at Research Center for Entomogenous Fungi, Anhui Agriculture University, China.