• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.92-97
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• 2001

Soil characteristics and crop productivity was compared between 5 soil physical treatment plots: check, reversion, subsoiling, explosive subsoiling and drainage in salt accumulated Gangseo Fine sandy loam soil from 1999 to 2000. Physical treatments of subsoil improved soil physical properties in the following order, reversion > drainage > explosive subsoiling > subsoiling > check. The effectiveness of physical treatment was sustained to the 2nd year after treatment. Soil moisture content of subsoil was highest in the reversion treatments and decreased in the order of drainage, subsoiling, and check. However there was little difference between treatments. The physical treatments increased fluctuation of soil moisture content. However the crop yield in the physical treatment plots were increased. It was considered that the increase of crop yield was caused by improvement of soil physical properties rather than soil water holding in the soil. An average increase rate of crop yield by physical treatments was 10 to 20 percent.

• Explosives and Blasting
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• v.22 no.2
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• pp.1-11
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• 2004

일반적으로 국내 석회석 광산에서의 발파는 20ms나 25ms 시차를 가지는 지발발파로 시행되어지고 있다. 국외에서는 전자뇌관을 사용하여 암반의 지질학적인 특성에 따라 지발 시차를 사용자의 현장에 따라 선정하여, 주변 보안 물건에 따른 진동 및 소음을 경감하면서, 1회 발파의 생산량을 증대할 수 있으며, 2차 파쇄 비용 및 적재비용을 절감하는 최적의 시차를 적용하여 발파 규모를 줄이지 않는 발파패턴을 적용하고 있다. 본 연구는 해외에서 사용되고 있는 전자뇌관을 국내 현장 석회석 광산(단양)에 적용함으로 최적지연시차를 찾아내는 방법과 초시의 오차에 따른 문제점과 향후 국내 적용성을 판단하고자 하였다. 대규모 석회석 광산을 대상으로 최적시차를 판단하고자 동일 패턴에서 시차를 6ms ~ 30ms로 시험발파를 시행하여 4가지 요소 발파진동속도, 주 주파수특성, 파쇄입도, 암석 이동 및 버력의 상태를 분석하여 각 시차에 따른 배점을 두어, 당 현장에 요구되는 개별 가중치를 선정하여 분석하였다. 분석 결과 당 현장에서의 발파결과에 따른 요소별 가중치를 발파진동속도(20), 주 주파수 특성(20), 파쇄입도(40), 암석 이동(10) 및 버력의 상태(10)로 하여 분석한 결과 15ms가 최적시차로 나타냈다. 향후 각 현장에 적합한 요소별 가중치를 선정하여 현장별 최적시차를 도출한다면 최적의 발파효과를 있을 것으로 판단된다.

• Journal of Life Science
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• v.7 no.2
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• pp.79-87
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• 1997

To determine the cause of Vibrio septicemia by understanding the characteristics endotoxin from Vibrio vulnificus, lethal dose, heat resistance and vascular permeability enhancing activity were svaluated using vegestative cell and cell homogenate and the result is as follows: 1. Vibrio vulnificus CDC B3547 of patient origin did not exihibit any significant difference in toxicity compared to Vibrio vulnificus B57 of enviroment origin. 2. Strong toxicity was observed when viable cell count of Vibrio vulnificus CDC B3547 was more than 10$^{7}$/ml. 3. Toxicity of cell homogenate was completely inactivited upon geating at 80$^{\circ}$C for 20min. 4. Cell homogenate did not show hemolyic activity but was acknowleged to have cytotoxicity. 5. Major lethal toxin against mouse was existed in Vibrio vulnificus CDC B3547; however, separation of LPS and LPS-protein complex was not successful using the current technique.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.228-231
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• 2012

In this work, the mixture of sewage sludge incubated in an anaerobic bioreactor for 35 days and paperboard sludge was treated in a batch anaerobic digester equipped with a ultrasonicator, and methane production during the treatment was investigated. The Soluble Chemical Oxygen Demand (SCOD) increased with increasing the amplitude of ultrasonicator, which help solubilizing paperboard sludge more effectively. The optimum amplitude of ultrasonicator for the enhancing methane productivity was found to be $142.5\;{\mu}m$ and the methane production amount increased as the anaerobic digestion period became longer. In addition, the anaerobic digestion was performed with various biomass (6000, 9000 and 12000 mg/L) and methane production increased with higher cell mass. These results will be used as valuable data to enhance the methane production from anaerobic digestion of the high concentration of organic wastes containing the paperboard sludge and sewage sludge.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.392-395
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• 2007

Recently, the construction wastes rapidly increase because of redevelopment, the development of new urbanization of large housing development, the expansion of social infrastructure. With increase of the construction noise caused by these developments, environmental conflicts and civil appeals increase. Moreover, the Government will reduce construction noise level to 65dB from 70dB in January 2009. Therefore, it will be expected to increase environmental conflicts and civil appels related to construction noise. To minimize environmental conflicts and civil appels, this study compared and analyzed measured noisy values of a crusher for the site-recycling to predicted value of simple noisy prediction program developed by "National Institute of Environmental Research". Based on the results, a crusher for the site-recycling can be arranged to minimize the noise.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.13-19
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• 2015

This paper presents a hydraulic fracture propagation model to describe propagation more realistically. In propagating the hydraulic fractures, we have used two criteria: maximum tangential stress to determine the fracture initiation angle and whether a hydraulic fracture intersects a natural fracture. The model was validated for the parameters relevant to fracture propagation, such as initiation angle and crossing ability through natural fracture. In order to check whether a hydraulic fracture crosses a natural fracture, the model results on crossing state excellently matched with the experimental data. In the sensitivity analysis for direction of maximum horizontal stress, frictional coefficient of fracture interface, and natural fracture orientation, the results show that hydraulic fracture intersects natural fracture, and then, propagated suitably with theoretical results according to fracture interaction criterion. In comparison of this model against vertical fracture approach, it was ascertained that there are discrepancies in fracture connectivity and stimulated reservoir volume.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.254-260
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• 1999

This experiment was carried out to evaluate the effect of improvement of soil physical property such as deep plowing and chiseling and diagnostic application of N, P, K fetilizers. Latex Coated Urea(LCU), compost, sillicate for increasing yielding and enchancing N-use efficiency in puddled-soil drill seeding of Rice. The soil physical properties, such as bulk density, hardness and porosity were increased by deep plowing and chiseling, as well as chemical propeties were highly enhanced soil productivity due to increase the content of organic matter, available $P_2O_5$ and K as compare with control. The amount of $NH_4-N$ in soil was highly increased by diagnostic fertilization and chiseling, while recovery rate of V fertilizer was the highest at LCU 80% applied with chiseling. The rice yield increased by 23% under the diagnositic application of LCU 80% applied base with chiseling.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.85-89
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• 2019

Cell-free protein synthesis utilizes the translational machinery in a cell extract. Unlike the conventional cell-based expression methods, not being affected by the conditions for cell growth, cell-free protein synthesis enables flexible manipulation of individual factors affecting the efficiency protein biosynthesis. However, the high cost and low stability of the energy sources to regenerate ATP have limited the use of cell-free synthesis for large-scale production of recombinant proteins. One of the approaches to address this problem is to use glucose as an alternative energy source to regenerate ATP through the glucose-metabolizing pathways in a cell extract. In this study, in an attempt to improve the efficiency of ATP regeneration by reinforcing oxidative phosphorylation process, we supplemented with cellular lipids to a glucose-fueled reaction mixture for cell-free protein synthesis. As a result of the lipid supplementation, the productivity of chloramphenicol acetyltransferase in a cell-free synthesis system using glucose increased more than 6 fold compared to when the lipid was not supplemented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.493-502
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• 2016

This study examines how rock condition affects the variation of the chargeability and electrical resistivity of the rock. In the theoretical study, the relationship correlating chargeability with the variables affecting it is derived. A parametric study utilizing the derived relationship reveals that the size of narrow pores ($r_1$) is the most influential factor on chargeability, and the salinity of pore water ($C_0$) is the second. In the laboratory experiments, small scale rock fracturing zone is modelled using sand stone. Chargeability and resistivity are measured by changing the size of the joint aperture, the location of fractured zone and the existence of clay gouge and/or clay layer which shows lower chargeability than the sand stone layer in the multi-layered ground. Test results show that chargeability is controlled not by the rock fracturing condition but by the size of narrow pore ($r_1$) where each line of current flow passes through. Also, the chargeability decreases with increase of the pore water salinity ($C_0$). In conclusion, the ground condition can be identified more efficiently by measuring the induced polarization along with the electrical resistivity; identifying the existence of sea water, the layered ground and/or the fractured rock becomes more reliable.

• Journal of the korean veterinary medical association
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• v.35 no.1
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• pp.22-26
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• 1999