• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.297-299
• /
• 2004

하수처리장의 2차유출수를 농업용수로 재이용 할 때 가장 문제가 되는 요소는 염도(Salinity)와 SAR(Sodium adsorption ratio)이다. RO와 NF 막분리 공정을 사용하여 각각의 결과값을 비교$\cdot$분석하고 재이용 시 이용될 적합한 막공정에 대한 지침을 마련하고자 하였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.3 no.2
• /
• pp.91-93
• /
• 1974

본(本) 논문(論文)은 유효온도차(有效溫度差)에 의(依)한 하기랭방부하계산법(夏期冷房負荷計算法)의 기초가 되는 서울에서의 상당외기온도(相當外氣溫度)를 구(求)한 것이다. 상당외기온도(相當外氣溫度)는 유효온도차(有效溫度差)를 구(求)하기 위한 것으로 이것의 산출(算出)은 서울의 외기온(外氣溫)을 T.A.C.(Technical Advisory Committee) 2.5% 위험율을 기준치(基準値)로 한 하기(夏期)의 설계용(設計用) 외기온도(外氣溫度)와 이론식(理論式)에 의한 전일사량(全日射量)에서 7월(月) 22일(日) 서울의 상당외기온도표(相當外氣溫度表)를 작성(作成)하였다.

• Journal of Biomedical Engineering Research
• /
• v.19 no.4
• /
• pp.333-339
• /
• 1998

The effect of heat treatment conditions on the properties of tungsten(W) embolization coils has been evaluated. The W embolization coils were fabricated by coiling the primary W coil with a diameter of 30.mm on a alumina rod mandrel with a diameter of 2.92mm. The secondary coils were then heat treated at 475$^{\circ}C$and 600$^{\circ}C$ for various heat treatment time ranging from 5 minutes to 36hours. The pitch distance, diameter and shape retention capability of the W embolization coils were characterized after the heat treatment. The pitch distance of the W embolization coils increased with the heat treatment time. The diameter of W emboliazation coils decreased continuously with heat treatment time. The shape retention capability of the W embolization coils increased with the heat treatment time due to an increase in elasticity by formation of tungsten oxide film on W coil surface during the heat treatment. The heat treatment condition of W embolization Col at 600$^{\circ}C$ for 20 minute was considered desirable based on the optimization of the shape retention capability, pitch distance and secondary coil diameter after heat treatment.

• Korean Journal of Poultry Science
• /
• v.2 no.1
• /
• pp.7-15
• /
• 1975

5주령시 병아리에 대하여 볶은 콩을 이용한 고열량 사료 1030Cal구 ($T_2$ 구)를 만들고 이를 830Cal의 관용사료구(C구)와 5주간 비교시험 한 결과 다음과 같은 성적을 얻었다. 1) 증체량에 있어서 $T_1$, $T_2$구는 C구에 비하여 증체량이 높으며 5%수준의 유의차가 있었다. 한편 L.S.D.-Test에 의하면 $T_1$과 C구 사이에만 5%의 유의차를 보였다. 2) 사료섭취량에 있어서는 $T_2$, $T_1$, C구의 순으로 사료를 절약할 수 있는데 L.S.D.-Test에 의하면 $T_2$구와 C구간에 1%의 유의차가 있으며 약 9%의 사료가 절약되었고 $T_1$구와 C구간에는 5%의 유의성이 있고 약 3%의 사료가 절약되었다. 3) 경제성에 있어서 추일수당 사료비는 $T_1$, $T_2$구 모두 C구보다 고가의 경향이 있어 볶은 콩의 실용가치를 감소시킨다. 그러나 육계 판매가격에 있어서 $T_1$구는 24.85원의 이익으로 C구 26.43원보다 하회하는 결과를 보인다. (중략)

• Journal of Bio-Environment Control
• /
• v.25 no.4
• /
• pp.277-282
• /
• 2016

This study was aimed to investigate the effect of air-circulation fans on air temperature and relative humidity in a single-span tomato greenhouse (W: 7m, L: 25m, H: 3.2m). According to standard of fan layout by ASAE (1997), a total of 10 fans were bilaterally arranged in 2 rows in the experimental greenhouse. The distributions of air temperature and relative humidity were measured from 6 pm to 8 am under different conditions, with and without fans. The measurement heights were 0.7m, 1.7m and 2.7m. Under the condition of "fans off", the spatial differences of air temperature and relative humidity between upper and lower sides were $1.7^{\circ}C$ and 10.8%, respectively. The operation of 10 fans showed their differences to $0.1^{\circ}C$ and 3.2%. The number of fans and installation direction were evaluated their performance on reducing the spatial variation of air temperature and relative humidity. The experimental layouts were 5 and fans in 2 rows (bilaterally) and 10 fans in the one (same) direction. Under the condition of "6 fans on" and "5 fans on", the spatial differences of air temperature and relative humidity between upper and lower side were $0.3^{\circ}C$, 3.4% and $0.3^{\circ}C$ and 4.0%. The operation of 10 fans in the one direction reduced their differences to $0.5^{\circ}C$ and 4.9%. The overall findings of this study showed that there was no significant differences under each condition. Therefore, this study suggested that it is more economic and effective to install five fans in 2 rows (bilaterally) in the greenhouse (W: 7m, L: 25m, H: 3.2m).

• TTA Journal
• /
• s.155
• /
• pp.93-100
• /
• 2014

• LOGISTICS
• /
• v.2 no.1 s.3
• /
• pp.33-37
• /
• 2004

한국물류협회(회장 서병륜)와 한국로지스틱스 학회, 대한상공회의소, 매일경제, 물류신문가가 공동으로 주최하고 ㈜아세테크, ㈜덕유, 로지스올 그룹이 후원한 제9차 물류정책토론회가 지난 12월 11일 대한상공회의소 제1회의실에서 개최됐다.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.9 no.2
• /
• pp.143-150
• /
• 1976

A trial has been made to find out a new method of calculating the survival rate of a fish Population utilizing the length composition data and the characteristics of the frequency curve of the length which usually is normal distribution curve. In this paper, a stochastic method is introduced and applied to calculate the survival rate of yellow croaker caught by Korean trawlers in the Yellow Sea and the East China Sea in 1971. The results are as follows : Mean of survival rate 0.46089 Variance 0.03073 Standard deviation 0.17529 95 percent confidence interval 0.36040-0.56138.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.41 no.6
• /
• pp.52-61
• /
• 2013

This study was conducted to investigate the effects of pergola's shading on the thermal comfort index in the summer. The 3 type of pergolas($4m{\times}4m{\times}h2.7m$) which were screened overhead(I)/overhead west(II)/overhead west north(III) plane with reed blind for summer shading and winter wind break, were constructed on the 4th floor rooftop. Thereafter the meteorological variables(air temperature, humidity, radiation, and wind speed) of pergola I, III and rooftop were measured from 14 to 16 August 2013(1st experiment), those of pergola I, II and rooftop were measured from 26 to 28 August 2013(2nd experiment). The effects of pergola's shading on the radiation environment and mean radiant temperature($T_{mrt}$), standard effective temperature($SET^*$) were as follows. The maximum 1 h mean values of differences ${\Delta}$ of the sums of shortwave radiant flux densities absorbed by the human body (${\Delta}K_{abs,max}$) between pergola I, III and nearby sunny rooftop were $-119W/m^2$, $-158W/m^2$, those between pergola I, II and rooftop were $-145W/m^2$, $-159W/m^2$. The maximum 1 h mean values of differences ${\Delta}$ of the sums of long wave radiant flux densities absorbed by the human body (${\Delta}L_{abs,max}$) between pergola I, III and nearby sunny rooftop, were $-15W/m^2$, $-17W/m^2$, those between pergola I, II and nearby rooftop, were $-8W/m^2$, $-7W/m^2$. The response of the direction dependent long wave radiant flux densities $L_1$ on the pergola's shading turned out to be distinctly weaker as compared to shortwave radiant flux densities $K_1$. The pergola's shading leads to a lowering of $T_{mrt}$ and $SET^*$. The peak values of $T_{mrt}$ absorbed by the human body were decreased $16^{\circ}C$ and $21.4^{\circ}C$ under pergola I and III as compared to that of nearby rooftop in the 1st experiment. Those were decreased $18.8^{\circ}C$ and $20.8^{\circ}C$ under pergola I and II as compared to that of nearby rooftop in the 2nd experiment. The peak values of $SET^*$ absorbed by the human body were decreased $2.9^{\circ}C$ and $2.6^{\circ}C$ under pergola I and III as compared to that of nearby rooftop in the 1st experiment. Those were decreased $3.5^{\circ}C$ and $2.6^{\circ}C$ under pergola I and II as compared to that of nearby rooftop in the 2nd experiment. The relative $SET^*$ decrease in pergola II, III compared to nearby sunny rooftop $SET^*$ were lower than that in pergola I, revealing the influence of the wind speed. Therefore it is essential to design pergola to maximize wind speed and minimize solar radiation to achieve comfort in the hot summer. The $SET^*$ under pergola I, III were exceeded $28.7^{\circ}C$ and $30.4^{\circ}C$ which were the upper limit of thermal comfort and tolerable zone during all most daytimes in the 1st experiment(maximum air temperature $37.5^{\circ}C$). The $SET^*$ under pergola I was exceeded $28.7^{\circ}C$ which was the upper limit of thermal comfort zone at 13h, that under pergola II was exceeded $28.7^{\circ}C$ from 8h to 14h, meanwhile the $SET^*$ under pergola I, II were within thermal tolerable zone during most daytimes in the 2nd experiment(maximum air temperature $34.4^{\circ}C$). Therefore to ensure the thermal comfort of pergola for summer hottest days, pergola should be shaded with not only reed blind but also climbing and shade plants. $T_{mrt}$ and $SET^*$ were suitable index for the evaluation of pergola's shading effects and outdoors.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.3
• /
• pp.402-408
• /
• 2016

Master packaging system consists of an inner individual package and secondary outer package. During the stages of chilled transport and distribution, the combination of primary individual package and secondary package was used to maintain a modified atmosphere for shiitake mushrooms. During the retail stage at higher temperature ($25^{\circ}C$), the primary individual package was exposed to display conditions after dismantling of the secondary packaging. The master packaging system was constructed to contain eight individual $30-{\mu}m$ thick polypropylene film bags of 500 g shiitake mushrooms inside a $40-{\mu}m$ low-density polyethylene bag. Carbon dioxide absorbent material [$Ca(OH)_2$] and/or moisture absorbent (superabsorbent polymer) were designed in their required amounts based on respiration characteristics and then applied to the outer secondary packaging in sachet form. Gas concentration of the packaging, temperature, and humidity were monitored throughout transport and storage. The quality of shiitake mushrooms was measured at the retail stage to determine the packaging effect. During the distribution stage of 108 h, $O_2$ and $CO_2$ concentrations in the master packaging system were maintained at 9~11% and 1~4% in the inner packaging, respectively, which are good for quality preservation. Compared to the control, the master packaging with $CO_2$ and/or moisture absorbents improved mushroom preservation and particularly reduced decay.