• 월간 기계설비
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• s.309
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• pp.28-37
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• 2016

관람석에서 바비큐를 먹으며 경기를 보거나 좀더 가까이 선수들을 볼 수 있는 야구장. 탁 트인 구장으로 경기장 밖에서도 선수들과 관중들을 보면서 함께 즐길 수 있는 야구장. 야구팬들이라면 누구나 미국 메이저리그 야구장에서만 볼 수 있는 풍경을 국내에서도 볼 수 있기를 꿈꾸었을 것이다. 최근 그 꿈이 실현됐다. 바로 지난 3월 19일 시범경기 개막전을 치른 '대구삼성라이온즈파크' 야구장이다. 미국 메이저리그 필라델피아 필리스의 홈구장인 '시티즌스뱅크파크'의 모양을 벤치마킹한 '대구삼성라이온즈파크' 야구장은 국내 최초로 팔각형으로 설계돼 넓은 관람공간과 탁 트인 시야가 특징이다. 지난 2012년 12월 첫 삽을 뜬 후 40여 개월 만에 총사업비 1,666억원을 투입해 지난 3월 완공되었다. '대구삼성라이온즈파크'는 야구 명문인 대구 경북의 자긍심과 함께 대구의 새로운 랜드마크로 자리매김하며 도시브랜드 향상과 더불어 시민들의 놀이, 휴식공간, 나아가 전국의 야구팬들이 찾고 싶은 관광 명소가 될 것으로 기대를 모으고 있다. 대구광역시 수성구 연호동에 위치한 대구삼성라이온즈파크는 (주)대우건설컨소시엄이 종합 시공을, (주)백산이엔씨가 냉 난방, 위생, 소방 등 기계설비를 시공했다. 본지는 준공 후 마무리 작업이 한창인 지난 3월 중순 대구삼성라이온즈 파크 현장에서 (주)대우건설 금현철 현장소장과 (주)백산이엔씨(대표 김주환) 김재화 현장소장을 만났다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.334-334
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• 2010

반도체 소자 제조 공정에 사용되는 공정 펌프는 전체 소요되는 에너지(소비전력)에 52%를 소비하고 있다. 이러한 이유 때문에 반도체 fab 내에서 에너지 절감을 논의할 때 항상 공정용 진공 펌프가 1 순위에 오를 수밖에 없는 것이다. 반도체 공정용 진공 펌프는 사용되어지는 공정에 따라 유지되는 진공도가 달라지고 이에 따라 소비전력과 투입되는 utility의 양이 바뀌게 되어 진공도와 공정에 따른 에너지 소비의 pattern이 다르다. 한국표준과학연구원 진공센터에서는 각 공정 대응용 펌프의 종류에 따라 배기속도, 도달진공도, 소비전력, 진동, 소음 등 기본 펌프 성능 평가, light gas인 helium에 대응하는 기본 성능평가를 실시하고 있다. 또한 부가적으로 soft/medium 공정용의 경우 저전력 mode의 소비전력의 진공도에 따르는 측정변수의 pattern을 측정/분석하고 있으며, harsh 공정용의 경우 50~300 slm의 유량 주입에 따른 내구성 특성을 monitoring하고 있다. 드라이펌프의 기본적인 평가 성능과 각 회사의 SPM (single pump monitoring system) 측정 변수인 온도, 배기구 압력 변화 등의 자체 진단 인자를 포함하여 반도체 공정에서 드라이 펌프의 운용에 필요한 냉각수, $N_2$, 등과 같은 utility의 사용량 및 온도변화 등을 측정하여 드라이 펌프의 에너지 소비 pattern을 분석하고자 한다.

• Journal of Powder Materials
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• v.26 no.2
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• pp.107-111
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• 2019

The activation energy to create a phase transformation or for the reaction to move to the next stage in the milling process can be calculated from the slop of the DSC plot, obtained at the various heating rates for mechanically activated Al-Ni alloy systems by using Kissinger's equation. The mechanically activated material has been called "the driven material" as it creates new phases or intermetallic compounds of AlNi in Al-Ni alloy systems. The reaction time for phase transformation by milling can be calculated using the activation energy obtained from the above mentioned method and from the real required energy. The real required energy (activation energy) could be calculated by subtracting the loss energy from the total input energy (calculated input energy from electric motor). The loss energy and real required energy divided by the reaction time are considered the "metabolic energy" and "the effective input energy", respectively. The milling time for phase transformation at other Al-Co alloy systems from the calculated data of Al-Ni systems can be predicted accordingly.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.471-476
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• 2022

PP/KF felt was used to load a high content of kenaf fiber (KF) into polypropylene (PP), and polyurethane (PU) was used as a binder. In order to find an optimum composition ratio of the PU binder, the flexural strength of the PP/KF/PU felt composite according to the isocyanate and polyol ratio was evaluated. PP-g-MAH grafted with maleic anhydride (MAH) was applied as a compatibilizer. Tensile, flexural, and impact properties were evaluated to consider changes in mechanical properties of the PP/KF/PU felt composite, and the properties were improved.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.385-392
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• 2021

When ordering a slurry shield TBM to be used for power cable tunneling, the client organizes an evaluation committee composed of experts, suggest the criteria and evaluation method for technical specifications for supplier selection, and based on the manufacturer's technical proposal were attempted to evaluate and select. It is expected to be referred to as a guideline for future projects to using Shield TBM as one of the methods of verifying performance and quality in advance and securing economic feasibility in the shield TBM tunneling in the recent increasing trend.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.93-99
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• 2015

The purpose of this study was to determine the appropriate temperature for water curtain in greenhouses equipped with recirculated water curtain system. The study analyzed the changes in air temperature in non-heated greenhouses for strawberry cultivation based on outdoor temperature, water curtain temperature and night time. Three greenhouse units were used for this study: The first unit was assigned as a control (no water curtain system), two other greenhouses were equipped with recirculated water curtain system with water curtain temperatures of $10^{\circ}C$ and $15^{\circ}C$, respectively. Analysis showed that the indoor temperatures were directly correlated with the outdoor temperature in all experimental greenhouses. Heat insulating effect of $15^{\circ}C$ water curtain was increased by $1.3^{\circ}C$ compared to that in $10^{\circ}C$ water curtain system. The $15^{\circ}C$ water curtain treatment showed the highest average temperature and less temperature variation in comparison with control and $10^{\circ}C$ water curtain treatment. To maintain indoor temperature at $5^{\circ}C$, water curtain temperature of $10^{\circ}C$ was suitable when outdoor minimum and average temperatures were -1.3 and $1.5^{\circ}C$, and water curtain temperature of $15^{\circ}C$ was suitable when outdoor minimum and average temperatures were -4.7 and $-0.2^{\circ}C$, respectively. The highest temperature in greenhouses according to measurements in different periods of night time was observed after sunset (18:30-20:30), and the lowest temperature before sunrise (05:00-07:00). Water curtain maintained a target indoor temperature by acting as a layer of heat transfer insulator which decreased heat loss from greenhouses. Therefore, water temperature in recirculating water curtain systems should be determined by considering outdoor temperatures, changes in temperature at different periods of night time, and cultivated crop.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.98-104
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• 1994

Effects of paddy-upland rotation system on nutrients distribution in soil profile and nutrient balance were studied in paddy fields from 1989 to 1993. The obtained results are summarized as follows. 1. $NO_3{^-}-N$, Av.$P_2O_5$, Ex.-K, and EC were high by small extent in surface layer of 0~20cm soil depth without the sign of salt movement to deeper layers. On the contrary Ex.-ca, Ex.-Mg, and pH became high with increase of soil depths. 2. $NO_3{^-}-N$, Av.$P_2O_5$, Ex.-K, and EC in surface soil were high in the order of Converted, Paddy-Upland Rotation, Potato-Chinese Cabbage>2 Year, Rotation, Potato-Chinese Cabbage>Converted, Paddy-Upland Rotation, Soybean>Continous Paddy, which responded well to fertilizer application rates. On the other hand Ex.-Ca, Ex.-Mg, and pH in whole layers were high in the order of Converted, Paddy-Upland Rotation, Soybean>Converted, Paddy-Upland Rptation, Potato-Chinese Cabbage>2 Year, Rotation, Potato-Chinese Cabbage>Continuous Paddy, which largely depended on plant absorption. 3. Nutrient balance in upland cropping system cultivating potato and Chinese cabbage showed that the input of chemical fertilizer of nitrogen and potassium was less than the plant uptake, while it was reverse for phosphorus with much gap between fertilizer input and plant uptake. Therefore, phosporous was expected to be accumulated by 27kg/10a every year. 4. Nutrient balance in upland cropping system cultivating soybean showed that nitrogen was not deficient to soybean crops even the chemical fertilizer input was less than plant uptake because of nitrogen fixation by rhizobia. However, there was about 1kg/10a deficit of potassium, which resulted dificiency symptom in the middle stage of soybean growth. For phosphorous there was excess of 4kg/10a, which was expected to be short for maintaining phosphorous fertility of upland soils.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.432-440
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• 2015

Biochar, a by-product from pyrolysis of biomass, is a promising option to mitigate climate change by increasing soil carbon sequestration. This material is also considered to have potential to remediate a soil with heavy metal pollution by increasing the soil's adsorptive capacity. This study conducted the assessment of two biochars considering the climate change mitigation potential and heavy metal removal capacity at the same time. Two kinds of biochars (BC_Ch, TW_Ch) were prepared by pyrolyzing the biomass of burcucumber (BC_Bm) and tea waste (TW_Bm). The soils polluted with Pb were mixed with biochars or biomass and incubated for 60 d. During the incubation, $CO_2$, $CH_4$, and $N_2O$ were regularly measured and the soil before and after incubation was analyzed for chemical and biological parameters including the acetate extractable Pb. The results showed that only the BC_Ch treatment significantly reduced the amount of Pb after 60 d incubation. During the incubation, the $CO_2$ and $N_2O$ emissions from the BC_Ch and TW_Ch were decreased by 24% and 34% compared to the BC_Bm and TW_Bm, respectively. The $CH_4$ emissions were not significantly affected by biochar treatments. We calculated the GWP considering the production of amendment materials, application to the soils, removal of Pb, and soil carbon storage. The BC_Ch treatment had the most negative value because it had the higher Pb adsorption and soil carbon sequestration. Our results imply that if we apply biochar made from burcucumber, we could expect the pollution reduction and climate change mitigation at the same time.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.143-148
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• 2011

The purpose of this study was to examine the usefulness of SPIO contrast agent in Magnetic Resonance Cholangiopancreatography (MRCP) by performing a quantitative comparative analysis in patients undergoing MRCP for gallbladder stones with and without oral injection of SPIO (Superparamagnetic iron oxide) contrast agent. The subjects were 36 patients undergoing MRCP for suspected gallbladder stones between January 2009 and February 2010 and they were divided into halves to compare the two groups of with and without SPIO agent. For each subject in both the injected and non-injected group, T2-weighted images on a 1.5T MR scanner were obtained, using both the breath-holding and respiratory-triggered methods, respectively. The following regions were measured; for breath-hold T2-weighted images, the measurement regions were located at the central part of the gallbladder, and the areas 15 mm away from its center, toward the front and back, respectively, which were chosen to include surrounding tissues, while for respiratory-triggered T2-weighted images, at the central part of the gallbladder, and segment 5 and 6 of liver. In a quantitative analysis, average signal to noise ratio (SNR) in each of regions of interest (ROI) for each group were calculated and then average contrast to noise ratio (CNR) in each of ROI were obtained by using the SNR in the gallbladder as the basis to compare and analyze the values between the two groups. The CNR were higher for the injected group in those regions.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.63-70
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• 2012

This study was conducted to investigated the distribution, ecological character and life cycle of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to the livestock feces. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, feces sheds, living waste dump grounds, and food waste dump grounds. Excellent species of the bio-conversion using the livestock feces were selected out of two kinds of solider flies(Hermetia illucens and Ptecticus tenebrifer). And effects of BSF on composing ability to the livestock feces were pig feces 0.5 g, cattle feces 0.43 g and chicken feces 0.3 g per a larvae of BSF. In the examination of the ability of BSF to decompose food waste, volume of the livestock feces decreased by weight pig feces 77, cattle feces 83.62 and chicken feces 80%. Observed characteristics of BSF larvae and pupae stage were by developmental stage may be summarized as follows: size and length of larvae and pupae of BSF were higher than in pig feces and mixed sawdust treatments. In order to develop artificial indoor rearing techniques, The pupation and emergence rate were not visible the difference but important factor of the mating and egg-laying was a sun light. And it was visible the difference in mating ratio. Mating rate of H. illucens by seasonal change was the highest from May to July. Mating mostly occurred between 10 : 00 and 12 : 00 during which light intensity is high. As the egg-laying medium for artificial egg collection, calf feed and food waste were most effective. The ratio of egg-laying medium is waste food : sawdust(1 : 1) in volume. For egg-laying materials, flower foam and wood with holes were used; holes sized 3 ~ 5 mm in diameter, 7 ~ 10 mm in depth were most preferred for egg-laying.