• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.3
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• pp.95-111
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• 2004

This research sought to determine the status of the installation and operation of composting facilities of domestic public resource-making facilities and come up with corresponding improvement measures. The composting facilities were the most extensively installed of related facilities with over a 0.5 ton treated volume per day. The monthly and yearly carry-in volume of food waste were found to stand at 1,101.7 tons per day and 930.9 tons per day, thus falling short of the average planned volume of 1,270.9 tons. Many composting facilities, which were installed in areas for which factory registration were not approved, did not get approvals. Composting facilities underwent operation stoppage mainly due to faulty fermentation and crushing equipment. Mainly metals contained in food waste caused faults to the crushing equipment, thus requiring a facility designing against faults and corrosion. The initial water content was found to stand at 50-60%, thus complying with the requirement. However, since the composting food waste had an appropriate mixture of sawdust, food waste, and returned compost, it should meet the initial conditions. For fermentation facilities, the duration time for fermentation was 15 days, and post-fermentation tanks required 21 days of duration time, thus establishing the minimum criteria. However, some facilities did not meet the requirements, taking more time in decomposition, thus suggesting a need to determine the duration time according to facilities. In composting food waste, microorganism-based thermal oxidizer-operated fermentation tanks should be used to ensure an economic operation. On the contrary, 14 out of 25 survey targets heated fermentation tanks in any form. These thermal facilities contain the growth of bacteria, lowering chemical reaction in composting; thus composting facilities should be basically designed to use microorganism-based thermal oxidizers in drying water. An average daily volume of food waste and supplementary materials that was injected in producing compost was 22.8 tons. This volume produced 7.3 tons of compost per day, decreasing 68%. Properties of produced compost were analyzed by its color, absence or presence of remaining decomposition heat, and smell, to assess the quality. As a result, the composting process was not properly installed nor operated in about 50% of composting facilities. Compost should be produced to be soil-friendly.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.5-13
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• 2017

With the purpose of energy recovery from sludge having calorific value as fuel we investigated the current status and characteristics of sludge in Korea in order to understand the type and amount of sludge that can recover energy. 'The Status Report on Waste Generation and Treatment in Korea' announced that 152 million tons of wastes were generated nationwide in 2015 and 9.2 % of the whole waste disposed into landfills which includes 15.1 % of the total industrial wastes. The average of upper calorific values of sewage sludge was 3,021 kcal/kg and that of wastewater sludge was 2,472 kcal/kg respectively. In order to determine the sludge as fuel, each correlations between calorific value, carbon content and combustibility ratio were evaluated. In the study, the current status and characteristics of sludge in Korea were investigated in order to understand the type and amount of sludge as fuel to recover energy. It is predicted that if the energy of sludge having a calorific value of 6 MJ/kg($${\sim_=}1,500kcal/kg$$) or more is recovered as fuel, the amount of the sludge disposed into landfills can be reduced about 40 %.

• Korean Security Journal
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• no.21
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• pp.155-175
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• 2009

RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.42-48
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• 2014

Soot and tar which were derived from combustion or pyrolysis processes in Puverized Coal(PC) furnace or boiler have been significantly dealing in a radiative heat transfer and an additional source of NOx. Furthermore, the increasing for the use of a coal with low caloric value gives rise to a lot of tar-soot yield and LOI in a recycled ash for using cement materials. So, the ash with higher tar-soot yield and LOI can not recycle due to decreased strength of concrete. In this study, tar-soot yields and flame structures were investigated using the LFR for a blending combustion with bituminous coal and sub-bituminous coal. Also, The investigation were conducted as each single coals and blending ratio. The coals are used in a doestic power plant. In the experimental results, sub-bituminous coal with high volatile contents shows longer soot cloud length than bituminous coal, but overall flame length was shorter than bituminous coal. Tar-soot yields of sub-bituminous coal is lower than those of bituminous coal. Combustion characteristics are different between single coal and blended coal. Therefore, finding an optimal coal blending ratio according to coal rank effects on tar-soot yields.

• 한국해양학회지
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• v.26 no.4
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• pp.295-303
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• 1991

Multi-spectral analyses of excitation and emission fluorescence was applied to spilled crude oils in characterization of their specific fluorescence patterns which is called oil fingerprints. In the present study, oil fingerprints of 33 crude, 4 fuel and 2 other oils were analyzed to establish data base library search system. Cluster analysis showed that crude oils could be classified into two large groups according to their fluorescence characteristics. In simulated experiments, all the spilled sources was identifiable by the present library search system. In the natural environment this system could identify the exact source of weathered crude oil slicks upton 10 days. The present study shows that the fluorescence fingerprinting method with the library search system is reliable and superior to toutine GC/HPLC analyses in identification of the source of weathered spilled oils in the marine environment.