• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2015.10a
• /
• pp.111-112
• /
• 2015

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.441-446
• /
• 2003

Cherry tomatoes, cucumbers and zuchinis stored in the far-infrared radiated chamber at 5$^{\circ}C$ or 10$^{\circ}C$ under 90% of relative humidity had been maintained in the fresh state for longer times than the control stored only in the cold chamber. Vegetables stored in the far-infrared radiated chamber showed lower values in weight loss rate, microbial colony count and decay ratio and higher ascorbic acid content than the control stored cold in the cold room through the storage period. We confirmed that vegetables stored in the far-infrared radiated chamber under low temperature and high humidity showed least changes in quality properties through the storage period and the far-infrared radiated facilities could be a good storage system.

• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.311-321
• /
• 2019

Greenhouse farmers often use thermal screens to reduce greenhouse heating expenses during the winter, and for shade during hot, sunny days in the summer, as it is an inexpensive solution to temperature control relative to other available options. However, accurate measurements of their emitted and absorbed radiations are important for the selection of suitable screens that offer maximum performance. Material's ability to save energy is highly dependent on these properties. Limited studies have investigated the measurement of these properties under natural conditions, but they are only applicable to materials having partial porosities. In this work, we describe a new radiation balance method for determining emissive power and absorptive capacity, as well as reflectivity, transmissivity and emissivity of materials having complete and partial transparency by using pyrgeometer and net radiometer. In this study, four materials with zero porosity, were tested. The emissivity value of PE, LD-13, LD-15 and PH-20 was $0.439{\pm}0.020$, $0.460{\pm}0.010$, $0.454{\pm}0.004$, and $0.499{\pm}0.006$, respectively. All tested samples showed high emitted radiation as compared to absorbed radiation.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.1
• /
• pp.20-28
• /
• 1989

SEA(Statistical Energy Analysis) method has been applied to predict the sound radiation power from vibrating machinery. In this study, sound radiation power was predicted from coupled structures by transmission of vibration, which composed of two plates welded into an L shape. The predicted sound radiation power is in agreement within 2 or 3 dB on octave band comparing with values obtained from direct measurements. Also, in order to prove the validity of this method in changes of sound radiation power associated with modifications to structures, rubber pad was stuck on a plate. The results agree approximately within 3 or 5 dB. And SEA method is valuable for the optimal design to reduce the noise. Additionally, this paper suggests that the logarithmic decrement method is valid as the one for finding the loss factor.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.5
• /
• pp.455-461
• /
• 2016

Survivability of an aircraft has been greatly threatened by the development of a weapon system using infrared. Therefore, the infrared stealth technology is a very important technique to improve the survivability of an aircraft. In this study, the infrared signal of an aircraft was analyzed which corresponding to the aircraft surface temperature and environmental conditions with various surface conditions(especially emissivity changed). Based on the analyzed infrared signal, the optimized surface emissivity was suggested to reduce the average contrast radiance and contrast radiant intensity(CRI). In addition, we confirmed that the infrared contrast radiant intensity between the aircraft and the background can be minimized through an appropriately controlled surface emissivity of the aircraft at specific background.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.2
• /
• pp.179-184
• /
• 2017

Due to rapid development of infrared guided weapon, survivability of armored vehicle is severely threatened. Hence, reduction of susceptibility by lowering infrared signature level is essential to enhance survivability of the vehicle. For this purpose, numerical analysis is conducted to analyze time and spatial characteristics of infrared signature of the vehicle when surface emissivity changes in this study. The analysis shows that the emissivity which produces minimum contrast radiant intensity is significantly altered by time and detecting position. Based on the result, it is concluded that the controlled structures which have different emissivity should be adopted at different region of the vehicle to effectively decrease infrared signature level.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.3
• /
• pp.82-88
• /
• 2013

In this project a preliminary experimental research work was done to apply mortars containing magnetite as fine aggregates unto floor finishing materials in order to make indoor environment eco-friendly and to have noiseproof control between floors. Crushed magnetites were substituted as sands in the mix design with a range of 0, 20, 40, 60, 100%. First far-infrared radiation tests to determine emissivity and emission power were done in accordance with the KICM test standard and an outstanding result was obtained. Density and compressive strength test results also showed that as the substitution increases, test values increase in a linear trend. However dry shrinkage test results revealed that as the substitution increases, shrinkage strain also increases. To clearly seek a solution about this problem, more experimental works should be done on oncoming experimental program.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.571-576
• /
• 1998

방사성물질의 수송용기 등에 사용되는 에폭시수지계 중성자 차폐재를 제조하였다 기본물질은 재질(KNS-102) 및 수소 첨가된 비스페놀 A힘(KNS-106) 그리고 패놀-노블락형 에폭시수지 (KNS-611)이며, 첨가제로는 수산화알루미늄 및 탄화붕소이다. 이들 중성자 차폐재들은 유동성이 좋아 수송용기와 같은 복잡한 구조에 사용할 수 있다. 제조된 중성자 차폐재들을 방사선 조사선 량에 대한 영향과 가압경수로 사용후핵연료_ 28다발을 수송할 수 있는 수송용기에 적용하여 차폐능 평가를 수행하였다 0.7 MGy 까지 중성자 차폐재들은 방사선 조사선량의 증가에 따라 중성자 차폐재의 거시적 제거 단면적($\Sigma$$_{R}$)은 약간 증가하는 경향을 나타내었으며, 수송용기에 적용하여 ANISN 전산코드로 차폐능 평가를 수행한 결과 정상수송시 중성자 차폐재의 두께가 12 cm 이상일 때 수송용기 반경방향표면에서 최대 방사선량율은 168 ~ 214 $\mu$Sv/h로 나타났으며, 수송용기 표면에서 100 cm 지점에서의 최대 방사선량율은 74 ~ 93 $\mu$Sv/h로 나타났다. 이들은 모두 관련된 법규들에서 규정된 최대 허용방사선량율을 만족하는 것으로 나타났다.

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.435-440
• /
• 2003

Such fruits as nut persimmons, mandarin oranges and apples stored in the far-infrared radiated chamber at 5$^{\circ}C$ under 90% of relative humidity had been maintained in the fresh state for longer times than the control stored only in the cold chamber. Fruits stored in the far-infrared radiated chamber showed lower values in weight loss rate, microbial colony count and decay ratio and higher ascorbic acid content than the control stored only in the told room through the storage period. We confirmed that fruits stored in the far-infrared radiated chamber under low temperature and high humidity showed least changes in quality properties through the storage period and the far-infrared radiated facilities could be a good storage system.

• Applied Chemistry for Engineering
• /
• v.17 no.6
• /
• pp.597-603
• /
• 2006

In order to study the effects of $GeO_{2}$ contents in $XSiO_{2}{\cdot}YGeO_{2}$ and $XSiO_{2}{\cdot}YNa_{2}O{\cdot}ZGeO_{2}$ compounds on far infrared ray radiation, we investigated the sample of $XSiO_{2}{\cdot}YGeO_{2}$ and $XSiO_{2}{\cdot}YNa_{2}O{\cdot}ZGeO_{2}$ using TG-DTA, XRD, FT-IR spectrophotometer and FT-IR spectrometer. The far infrared ray emissivity and emission power were increased with the increase of $GeO_{2}$ contents in $XSiO_{2}{\cdot}YGeO_{2}$ and $XSiO_{2}{\cdot}YNa_{2}O{\cdot}ZGeO_{2}$ compounds. The far infrared ray emissivity and emission power of $XSiO_2{\cdot}YGeO_2$ compounds were higher than those of $XSiO_{2}{\cdot}YNa_{2}O{\cdot}ZGeO_{2}$ compounds.