• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.712-718
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• 2005

This research was conducted to evaluate the effect of recycled-water addition on the treatment of coar tar-contaminated soil with slurry phase bioreactor. A bench-scale slurry phase bioreactor was maintained to optimize the microbial growth. Silty loam soil was used for this research. Concentrations of coal tar and 14 target PAHs (Polyunclear Aromatic Hydrocarbons) in the soil were determined with gas chromatography. Addition of recycled-water to slurry phase bioreactor was not significantly increased the removal efficiency of 2000 mg coar tar/kg. However, it significantly increased the removal efficiency of 20000 mg coar tar/kg. In 20000 mg coar tar/kg, the first order kinetic constant and the removal efficiency of the reactor with recycled-water addition were 2.5 and 2.0 times higher than those of the reactor without recycled- water addition. Coar tar in the slurry phase bioreactor was removed in 3.8~16.0% by vaporization and biodegraded in 84.0~96.2%. Removal efficiency of 3-ring compounds was high as 92.2~99.7% in the case of recycled-water addition. However, removal efficiencies of 3 and 4-ring compounds were low as 0~30%.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.105-118
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• 2008

Shotcrete is one of the main support materials in tunnelling. Its bonding state on excavated rock surfaces controls the safety of the tunnel: De-bonding of shotcrete from an excavated surface decreases the safety of the tunnel. Meanwhile, the bonding state of shotcrete is affected by blasting during excavation at tunnel face as well as bench cut. Generally, the bonding state of shotcrete can be classified as void, de-bonded, or fully bonded. In this study, the state of the back-surface of shotcrete is investigated using impact-echo (IE) techniques. Numerical simulation of IE technique is performed with ABAQUS. Signals obtained from the IE simulations were analyzed at time, frequency, and time-frequency domains, respectively. Using an integrated active signal processing technique coupled with a Short-Time Fourier Transform (STFT) analysis, the bonding state of the shotcrete can be evaluated accurately. As the bonding state worsens, the amplitude of the first peak past the maximum amplitude in the time domain waveform and the maximum energy of the autospectral density are increasing. The resonance frequency becomes detectable and calculable and the contour in time-frequency domain has a long tail parallel to the time axis. Signal characteristics with respect to ground condition were obtained in case of fully bonded condition. As the ground condition worsens, the length of a long tail parallel to the time axis is lengthened and the contour is located in low frequency range under 10 kHz.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.454-462
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• 2012

This study was to research the effective use of green rooftop space, facilities and gardening, targeting members from community rehabilitation centers with disabilities. The three community rehabilitation centers studied were, Namyangju Center located in a rural area, Seoul Center located in a urban area and Siheung Center located in both a rural and urban area. We analyzed the difference in preference on the basis of each local community area. In fact, it indicated that 50% of each center knew about the green rooftop at their facilities and its use as a place for taking walks and conversation. It also showed that there was the high preference for priority objects such as a bench, pergola and trash can. Also the preference for natural visualizations like herbal or ornamental plants. The study showed a high preference to a small vegetable plot, hands on gardening and ecological wetland. It also indicated that there was a high preference for experience in nature programs on the rooftops (28.9 %) versus the rate of horticultural programs (27%). Therefore, it proves that the composition of a green rooftop at a community rehabilitation center should be differentiated so that the green rooftop can be a place not only for resting, but also great for a natural learning experience and gardening therapy for people with disabilities.

• Explosives and Blasting
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• v.30 no.2
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• pp.86-97
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• 2012

Ground vibration induced by a bench blasting in the construction site should cause the damage to the structure and indirect damage to a human body, and the vibration level is most practical descriptor for regulating the damage to human body and peak particle velocity is the descriptor for direct damage assesment of the structure. Meantime, the vibration level has not been considered for the blasting design but this study is the case that apply not only peak particle velocity but also vibration level on the blasting design. Also, we strongly believe that this study will be helpful for the management in the blasting site which some civil appeal is concerned. Total 232 measurements of both ppv and vibration level was used to estimate the scale distance. When the regulating threshold was ppv 0.3 cm/s and vibration level 75 decibel, the charge per delay to be estimated with vibration level could be recommended by 1.2~1.4 times than it of ppv. So, it is proven that considering vibration level on the blasting design is reasonable for not only prevention of the civil appeals but also effective blasting. Again, the blasting design which follows the law, "Noise and Vibration Control Act" can actually serve good condition to carry much more economical and effective blasting. The instruments used for this study are the SV-1 model, as first instrument in korea which can measure vibration velocity and vibration level at the same time.

• Journal of Life Science
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• v.25 no.8
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• pp.932-935
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• 2015

The purpose of this study was the effect of complex training of obese men in their 30s on inflammatory markers and homocysteine, a risk factor for cardiovascular disease. The subjects consisted of obese men (n=12) with the body fat ratio of 25% or above in their mid 30s who had no medical conditions and can follow the exercise routine required by this study. To achieve the purpose of this study measured the maximum oxygen intake (VO_2max) and 1RM of 5 kinds of machine(bench press, lat pull down, arm curl, leg press, squat) as a preliminary test; based on the results, performed 8 weeks complex training (aerobic exercise + weight training); and then analyzed the variation in body composition (body weight, body fat and BMI), blood inflammatory markers (IL-6, TNF-α and CRP), and homocysteine between before and after training. The results exhibited that 8 weeks complex training reduced weight, body fat and BMI significantly (p<0.01) and also reduced inflammatory marker CRP and homocysteine, a risk factor for cardiovascular disease, significantly (p<0.05). In conclusion, 8 weeks complex training confirmed the variation in body composition, and this variation has a positive effect on the inflammatory marker and the risk factor for cardiovascular disease.

• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.61-70
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• 2014

Various procurement systems for Architecture-Engineering service for public construction project are currently established by construction-related law. However, comprehensive framework and criteria for the selection of Architecture-Engineering firm are in absence. Even though various selection methods for Architecture-Engineering service are currently established by law, cost-based selection method is mainly used in selecting Architecture-Engineering firm for the service. This paper examined current use of procurement system for Architecture-Engineering service and drew problems in practice. Through analysis of problems and bench-marking of those systems in advanced countries and international organizations, several strategies to improve performance of Architecture-Engineering service and to maximize the efficiency were suggested. The suggestions include framework and guideline to select a procurement method for the service which is being considered for the project and way of improving current procurement system. These suggestions will be a foundation for utilizing appropriate procurement system for the specific project and can make domestic Architecture-Engineering firm more competitive in the global market by breaking form the cost-based selection method in the selection of Architecture-Engineering firms.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.45-56
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• 1985

This study was made to evaluate temperature effects on biological wastewater treatment particularly at the lower temperatures. Cell yield coefficients and other kinetic factors were compared by varying temperature for industrial wastes. Bench scale aeration-only complete mixing activated sludge(CMAS) units were operated at temperatures of $1^{\circ}$, $4^{\circ}$, $7^{\circ}$ and $10^{\circ}C$ with substrate concentrations of 5,000 and 200 mg/l COD. The study results indicate that the cell yields were computed to be 0.5 to 0.6 grams VSS per grams BOD removed, and were not influenced by temperature variations. The synthesis/total energy ratios were computed to be 0.45 to 0.58 and had a tendency to become larger at lower temperatures. The endogenous respiration rates were computed to be 0.07 to 0.08/day, and seemed to be independent of temperature. In addition, very little temperature effects were observed when F/M ratio and substrate concentrations were reduced.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.3
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• pp.388-404
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• 2017

The Union of Kansai Governments of Japan is regarded as a bench marking for the successful cooperation, alliance, and cooperation of neighboring local governments. The Union of Kansai Governments was a realization several active plan of the Kansai Economic Federation. The purpose of this study is to examine the roles of the Kansai Economic Federation in the process for establishment of the Union of Kansai Governments, searching for theoretical implications for the inter-municipal cooperation of Gwangyand Bay in South Korea. In particular, this study review the activities and roles of the Kansai Economic Federation in relation with the establishment of a number of promotional organizations and governance systems. We played special attention to the three important factors carried out by the Kansai Economic Federation, that is, the contineous activities, the accumulated research results, and establishment of various promotion organizations and effective governance systems. We suggest, in conclusion, that these three factors would also have very important policy implications for the discussion of inter-municipal cooperation among three cities, Yeosu, Suncheon, and Gwangyang.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.81-88
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• 2000

Composting of N-rich wastes such as food waste and wastewater sludges can be associated loss of with substantial gaseous N, which means loss of an essential plant nutrient but may also lead to environmental pollution. We investigated the behavior of nitrogenous materials during the first high-rate phase in composting of food waste. Air dried food waste was mixed with shredded waste paper or wood chip and reacted in a bench scale composting reactor. Samples were analyzed for pH, ammonia, oxidized nitrogen and organic nitrogen. The volatilized ammonia nitrogen was also analyzed using sulfuric acid as an absorbent solution. Initial progress of composting reaction greatly influenced the ammonification of organic nitrogen. A well-balanced composting reaction with an addition of active compost as an inoculum resulted in the promoted mineralization of organic nitrogen and volatilization of ammonia. The prolongation of initial low pH period delayed the production of ammonia. It was also found that nitrogen loss was highly dependent on the air flow supplied. With an increase in input air flow, the loss of nitrogen as an ammonia also increased, resulted in substantial reduction of ammonia content in compost. The conversion ratio of initial nitrogen into ammonia was in the range of 28 to 38% and about 77~94% of the ammonia produced was escaped as a gas. Material balance on the nitrogenous materials was demonstrated to provide an information of importance on the behavior of nitrogen in composting reaction.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.