This study aimed to investigate the effect of Liriope platyphylla and organic acids on enteric methane mitigation in goats using an open-circuit simplified respiration chamber system. Methane recovery was evaluated by injecting 3% standard methane gas for 30 min at 3 L/min. The percentage of methane recovery from the four chambers was 99±5.4%. Following the recovery test, an animal experiment was conducted using eight castrated Boer goats (body weight 46.6±7.77 kg) using a 2×2 crossover design. Experimental diets were as follows: 1) Control (CON), commercial concentrate and tall fescue, and 2) Treatment (MIX), concentrate supplemented with L. platyphylla and organic acids and tall fescue. Goats were offered feed at 2% of body weight (dry matter basis) in equal portions twice daily at 8:00 and 15:30. The goats were adapted to the feed and methane chamber for 10 and 3 days, respectively. Methane emission was measured one day per goat using tunable diode laser absorption spectroscopy, and temperature and airflow measurements were used to estimate methane emissions. Dry matter intake (DMI), body weight, and methane emission were measured during each period. Methane production with CON and MIX was 24.48 and 22.68 g/d, respectively, and 26.81 and 24.83 g/kg DMI, respectively. Although the differences were not significant, the use of supplements resulted in a numerical reduction in methane in MIX compared with CON. Collaboration with experts in other areas, including various engineering departments, is imperative to measure methane emissions using a chamber system accurately.

PURPOSES : The number of snowfall and the amount of snowfall are gradually increasing, and due to the characteristics of Seoul, which has a lot of traffic, it is difficult to respond quickly with a snow removal method that relies on snow removal vehicles. Therefore, it is necessary to develop an IoT based eco-friendly snow removal system that can respond to unexpected heavy snow in winter. In this study, the low temperature operation and snow removal performance of the IoT road condition snow removal detector and the snow removal system using CNT and PCM are evaluated in the climatic environment chamber. METHODS : To make artificial snow, it consists of an climatic environment chamber that can simulate a low temperature environment and equipment that can supply compressed air and cold water. Depending on the usage characteristics of the climatic environment chamber, use an air-water type snow maker. In order to make artificial snow, wet temperature, which takes into account the actual air temperature and the amount of moisture in the air, acts as the most important variable and is suitable for making snow, below –1.5 ℃. The lower the water temperature, the easier it is to freeze, so the water source was continuously supplied at 0 ℃ to 4 ℃. One of the two different pipes is connected to the water tank to supply water, and the other pipe is connected to the compressor to supply high-pressure air. Water is dispersed by compressed air in the form of many small droplets. The sprayed microscopic water particles freeze quickly in the low temperature environmental climatic chamber air and naturally fall to the floor, forming snow. Based on the KS C IEC 60068-2-1 cold resistance test standard, an integrated environmental test procedure was prepared to apply to IoT-based snow removal systems and performance evaluation was performed accordingly. The IoT based eco-friendly snow removal system is needed to in winter, so visual check and inspect the operation at the climatic chamber before setting up it to the actual site. In addition, grid type equipment was manufactured for consistent and reliable snow removal performance evaluation under controlled environmental conditions. RESULTS : The IoT-based eco-friendly snow removal system normally carried out the task of acquiring data and images without damaging the appearance or freezing in a low temperature environment. It showed clear snow removal performance in areas where PCM and CNT heating technology were applied to the concrete slab. This experiment shows that normal snow removal tasks can be carried out in low temperature environments in winter. CONCLUSIONS : The integrated environmental test procedures and grid type evaluation equipment are applied to low temperature operation and snow removal performance evaluation of snow removal systems. In the climatic environment chamber, where low temperature environments can be simulated, artificial snow is created regardless of the season to derive quantitative experimental results on snow removal performance. PCM and CNT heating technology showed high snow removal performance. The system is expected to be applied to road site situations to preemptively respond to unexpected heavy snow in winter.

The use of nuclear materials for nuclear power generation is increasing worldwide, and the International Atomic Energy Agency (IAEA) has signed an agreement with countries using nuclear materials to prevent using military purpose through the Non-Proliferation Treaty (NPT) for the management of nuclear materials. Accordingly, all member countries manage nuclear material and equipment facilities under the treaty and are obligated to conduct safety measures such as inspection, containment, and surveillance in accordance with safety standards. The equipment used in the inspection basically consists of a Scintillator type and a semiconductor detector type, and is mainly used for portable equipment to ensure the integrity of the equipment. In general, the operating environment of the detector guaranteed by the manufacturer is -10 degrees to 40 degrees due to poor resolution and electrical problems. However, in the case of an outdoor environment other than a laboratory environment, it is difficult to maintain the above temperature conditions. In particular, the internal temperature of the vehicle used for transport rises to more than 50 degrees in Korea, making the detector stored therein vulnerable. In this study, a storage chamber for extreme environments was developed. The developed chamber compared the internal temperature by heating the external temperature. In addition, the performance before and after heating was compared by heating the radiation detectors HPGe, CZT, and NaI from -20 to 70 degrees Celsius while using the storage chamber. Our proposed chamber can play a key role in applications with good performance in complex environmental adaptability in their design.

This paper presents a computational fluid dynamics (CFD) analysis to investiagate the effect of expansion chamber on overpressure reduction in protective tunnels subjected to detonation of high explosives. A commercial CFD code, Viper::Blast, was used to model the blast waves in a protective tunnel with a length of 160 m, width of 8.9 m and height of 7.2 m. Blast scenarios and simulation matrix were establihsed in consideration of the design parameters of expansion chamber, including the chamber lengths of 6.1 m to 12.1 m, widths of 10.7 m to 97 m, length to width ratios of 0.0 to 5.0, heights of 8.0 m and 14.9 m, and ratios of chamber to tunnel width of 1.2 to 10.9 m. A charge weight of TNT of 1000 kg was used. The mesh sizes of the numerical model of the protective tunnel were determined based on a mesh convergence study. A parametric study based on the simulation matrix was performed using the proposed CFD tunnel model and the optimized shape of expansion chamber of the considered tunnel was then proposed based on the numerical results. Design recommendations for the use of expansion chamber in protective tunnel under blast loads to reduce the internal overpressures were finally provided.

Crassulacean acid metabolism (CAM) plants use surplus CO2 generated by cooling and heating at night when ventilation is not needed in a greenhouse. Schlumbergera truncata ‘Pink Dew’ is a multi–flowering cactus that needs more phylloclades for high–quality production. This study examined photosynthetic characteristics by the phylloclade levels of S. truncata in a growth chamber and a greenhouse for use of night CO2 enrichment. The CO2 uptake rate of the S. truncata’s top phylloclade in a growth chamber exhibited a C3 pattern, and the second phylloclade exhibited a C3 –CAM pattern. The CO2 uptake rate of the top phylloclade in a greenhouse showed a negative value both day and night, but those of the second phylloclade exhibited a CAM pattern. The stomatal conductance and water–use efficiency (WUE) of S. truncata at both the top and second phylloclades were higher in a growth chamber than in a greenhouse. The WUE of S. truncata in a growth chamber and a greenhouse was higher at the second phylloclade, which is a CAM pattern compared with those of the top phylloclade. The daily total net CO2 uptake of S. truncata was higher in a growth chamber than in a greenhouse. The daily total net CO2 uptake of S. truncata at the second phylloclade had the highest value of 155 mmol·m–2·d–1 in a growth chamber. The night total CO2 uptake of S. truncata at the second phylloclade was 3–fold higher in a growth chamber than in a greenhouse. S. truncata’s second phylloclade exhibited a CAM pattern that uptake CO2 at night, and the second phylloclade, was more mature than the top phylloclade. A multi–flowering cactus S. truncata ‘Pink Dew’ efficiently uptake night surplus CO2 in the proper environmental condition with matured phylloclade.

The Joseon royal family considered the act of burying the placenta very important for various reasons. Accordingly, they developed their own ritual culture of burying the placenta based on the geomancy(Pungsu). In 1661, The King Sukjong's placenta chamber was built in Gong-ju, and later stone objects were added in 1683. Since its establishment, the King Sukjong’s placenta chamer have been continuously managed by the Joseon royal family, but During the Japanese colonial period, the placenta chamber was partially destroyed, and now only some stone objects remain in the original site. This study aims to estimate the original style and structure of King Sukjong's placenta chamber by focusing on the stone objects which were discovered through recent field surveys. In addition to that, the stylistic review of Joseon Dynasty's royal placenta chamber was conducted to secure a literary data basis and acquired data were comprehensively analyzed. As a result, Some of the original style and structure of King Sukjong's placenta chamber could be confirmed. The results of this study are expected to help restore the authenticity of the royal placenta chamber damaged in japanese colonial period, and are expected to be a good example in the research methodology of historical evidence of other damaged royal placenta chambers.

본고에서는 『홍루몽』 텍스트에 소품으로 등장하는 역대 명화와 서예 작품들이 해 당 공간에서 어떠한 분위기를 조성하고 그곳에 사는 인물들과 어떠한 상호작용을 하 는지 분석함으로써 『홍루몽』 속 전통 서화 예술의 의의와 가치를 고찰해 보고자 하 였다. 『홍루몽』에서 서화는 인물의 성격을 드러내 보여주고 스토리를 이끌어가는 하 나의 중요한 서사적 장치로 운용되었다. 처음에는 서화의 자체적인 형상으로 독자에 게 다가가나 어느 순간 공간 속의 인물과 어우러지면서 모종의 의미체계로 독자에게 수용되고 있음을 알 수 있다. 그런 점에서 『홍루몽』의 서화 예술은 단순히 그림이나 글씨라고 하는 개별적인 소품의 차원에 머물지 않고 인물 감상 및 주제의 차원으로 확장되어 소설의 경계를 더욱 높은 수준으로 고양시켜 주었다고 하겠다.

The electrical resistances of small-sized activated carbon fiber (ACF) fabric (specific surface area: 1244.7 m2/ g, average pore diameter: 1.92 nm) and felt (specific surface area: 1321.2 m2/ g, average pore diameter: 2.21 nm) sensors were measured in a temperature and humidity controlled gas chamber by CO2 adsorption at different surrounding CO2 concentrations (3000–10,000 ppm). The electrical resistances of ACF sensors decreased linearly as the increase of temperature and decreased exponentially as the increase of humidity in the ambient atmospheric chamber. The electrical resistances of ACF rapidly decreased within 4 s and an equilibrium state was achieved within 10 s due to the very rapid CO2 adsorption at room temperature and 40% humidity. Comparing the difference in electrical resistance values measured during injection of similar concentrations of CO2 after reaching the equilibrium value, the fabric exhibited a significant change, whereas the felt did not, even though it had a relatively larger specific surface area. The reason is that micropore volume greatly affected the amount of CO2 adsorbed, whereas the specific surface area did not affect it as much. Therefore, ACF fabric with large micropores (> 2.0 nm) can be developed and used as CO2 sensors in small rooms such as a passenger vehicles.

The increase in temperature due to climate warming is predicted to affect crop yields in the future. Until now, various types of OTC (open top chamber) that simulate the future climate condition have been developed and used to study the effect of temperature increase due to global warming on maize growth. However, in most OTCs, high equipment and maintenance costs were required to artificially increase the temperature. This study was carried to develop a cost-effective and simple OTC suitable for climate warming experiments for forage maize. Three octagonal OTCs with a height of 3.5 m × a diameter of 4.08 m and a partially covered top were constructed. The lower part of OTC covered film was opened at a height of 26 cm (OTC-26), 12 cm (OTC-12) from the ground surface, or not opened (0 cm, OTC-0). Mean air temperatures during the daytime on a sunny day in OTC-0, OTC-12 and OTC-26 increased to 3.23℃, 1.33℃, and 0.89℃, respectively, compared to the ambient control plot. For a pilot test, forage maize, ‘Gwangpyeongok’ was grown at OTCs and ambient control plots. As a result, in the late maize vegetative growth phase (July 30), the plant height was increased more than 45% higher than the ambient control plot in all OTC plots, and the stem diameter also increased in all OTC plots. These results indicate that it is possible to set the temperature inside the OTC by adjusting the opening height of the lower end of the OTC, and it can be applied to study the response of forage maize to elevated temperature. An OTC, with its advantages of energy free, low maintenance cost, and simple temperature setting, will be helpful in studying maize growth responsiveness to climate warming in the future.

Recently, there has been growing interest in harmful substances released from household items such as volatile organic compounds (VOCs) and this has increased people’s environmental awareness. In this study, adhesives and manicures were used as samples of indoor household goods and formaldehyde emission and tested over time under temperature conditions of 15oC, 25oC, 35oC, and 45oC. The small chamber method as the indoor air quality process test method was employed and used to evaluate the concentration of formaldehyde emissions. As a result, formaldehyde emissions gradually decreased over time in both tests using adhesives and manicures. The cumulative emission showed a logarithmic function over time, and the formaldehyde can be released for longer periods of time at lower temperature conditions. The logarithmic value and response time showed linear relationships, and it can be inferred that the formaldehyde was released from the sample through the first order reaction. Furthermore, the relationship between temperature and velocity constants which was determined using the Arenius linear equation showed that the reaction rate of formaldehyde can be estimated by a temperature change.

본 연구에서는 처리용기의 재질에 따른 광펄스의 살균 효과에 대해서 알아보았다. 처리용기의 재질에 따른 UV-C 의 광량은 대조구는 3.595W/m2이었으며, 두께 1 mm에서 석영은 3.358W/m2, 아크릴은 0.878W/m2, 그리고 유리는 0.060W/m2였으며, 빛의 투과율은 석영은 93.4%, 아크릴은 24.4%, 유리는 1.7%로 나타났다. 처리 용기 재질에 따른 살균 효과는 석영은 처리용기의 두께와 상관없이 대조구와 동일한 살균 효과를 보였으며, 아크릴은 1 mm 두께에서 60초 처리 후 1.1 log 사멸하였으며, 180초 처리 후에는 5.0 log의 사멸효과를 보였으며, 두께가 증가함에 따라 살균 효과가 현저히 감소하였다. 유리는 두께와 관계없이 살균 효과가 거의 없었다. 사멸패턴은 유리를 제외하고는 모두 bi-phasic의 형태를 보였으며, 사멸속도상수와 D 값은 대조 구는 k1값은 0.287 s−1이었으며, k2값은 0.072 s−1이었고, D1 은 8.02 s였으며, D2는 31.87 s였다. 1 mm의 두께에서 석영 은 k1은 0.284 s−1, k2는 0.069 s−1, 아크릴은 k1은 0.018 s−1, k2는 0.042 s−1이었고, 유리는 k는 0.004 s−1이었다. 두께 1 mm에서 D값은 석영은 D1=8.11 s, D2=33.87, 아크릴은 D1 =127.94 s, D2=54.83 s, 유리는 D=575.75 s로 나타났다.

In the past, the U.S. NRC(Nuclear Regulatory Commission) strictly required testing of the EDG for NPP through Reg.Guide 1.108 Rev 1. However, these test requirements acted as a deterioration and wear factor for diesel engines, and are now applying Reg.Guide 1.9 Rev 3, which relaxed regulatory requirements and improved performance monitoring. After applying the new regulatory guidelines in this study, the EDG analyzed the performance of the combustion chamber. As a result, there were no signs of deterioration or decreased performance of the current EDG. This is due to slow start, short operation time, the use of high quality fuel oil and proper maintenance. On the other hand, if the performance is proven, it is judged that proper period extension of cylinder maintenance is possible.

본 연구는 이탈리안 라이그라스 원형베일 사일리지 조제에 있어서 원료작물의 수분함량과 베일러 챔버의 압력에 따른 사일리지의 사료가치와 발효품질의 변화를 구명하기 위하여 수행되었다. 수확 후 1일(고수분), 2일(중수분) 및 4일간(저수분) 각각 예건하여 서로 다른 수분함량의 이탈리안 라이그라스를 베일러 챔버 압력이 115, 130 및 145 bar로 설정된 베일러로 원형베일 사일리지를 조제하여 60일간 저장하였다. 베일 사일리지의 무게는 고수분 처리구에서 높게 나타났고, 건물중은 저수분 처리구가 유의적으로 높게 나타났다. 베일러 압력에 따른 사일리지의 무게는 유의적인 차이는 없었으나, 압력이 증가할수록 건물중은 증가하였다. 수분함량과 베일러 압력에 따른 사일리지의 NDF, ADF, CP 및 CF는 처리 간에 유의적인 차이가 없었으며, RFV (relative feed value)는 고수분 저압력 처리구에서 가장 높게 나타났다. Lactic acid는 고수분-고압력 처리구가 가장 높았으며, 저수분-중압력 처리구에서 가장 낮게 나타내었다. Butyric acid는 베일러 압력에 따른 유의적인 차이는 없었으나, 예건기간이 길어질수록 감소하였다. 사일리지 pH는 고수분 처리구가 중수분과 저수분 처리구에 비해 낮게 나타났으나, 베일러 압력에 따른 차이는 없었다. 이러한 결과는 이탈리안 라이그라스 원형베일 사일리지 조제 시 조사료의 수분함량과 베일러 챔버의 압력이 사일리지의 발효품질에 영향을 미치는 중요한 요인임을 나타내는 것이다.