• Clean Technology
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• v.18 no.3
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• pp.325-328
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• 2012

The condensation reaction of 9,9'-bis(4-hydroxyphenyl)fluorene with epichlorohydrin to prepare 9,9'-bis[4(glycidyloxy) phenyl]fluorene (2), an important building block for fluorene-containing epoxy polymers, has been studied. The reaction is found to be quite sensitive to several experimental conditions such as reaction temperature and time, added amount of epichlorohydrin, the presence of catalysts and the use of co-solvent. Several conditions for obtaining the best yield in the reaction are: the reaction temperature is below 373 K and the reaction time is shorter than 1.5 h, and the ammonium salts act as a catalyst. Also, the use of ternary solvent (toluene, DMSO, water) has been proved to be crucial to maintain the reaction temperature and for an easy purification. Thus, the reaction proceeds in an environment-friendly manner where the use of reactants and the production of chemical wastes is minimized.

• Journal of Environmental Science International
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• v.16 no.10
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• pp.1203-1208
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• 2007

Feathers are produced in huge quantities as a waste product at commercial poultry processing plants. Since feathers are almost pure keratin protein, feather wastes represent an alternative to more expensive dietary ingredients for animal feedstuffs. Generally they become feather meal used as animal feed after undergoing physical and chemical treatments. These processes require significant energy and also cause environmental pollutions. Therefore, biodegradation of feather by microorganisms represents an alternative method to prevent environment contamination. The aim of this study was to investigate cultural conditions affecting keratinolytic protease production by Bacillus pumilus RS7. We also assessed the nutritive value of microbial and alkaline feather hydrolysates, The composition of optimal medium for the keratinolytic protease was fructose 0.05%, yeast extract 0.3%, NaCl 0.05%, K2HPO4 0.03%, KH2PO4 0.04% and MgCl2 6H2O 0.01%, respectively. The optimal temperature and initial pH was $30^{\circ}C$ and 9.0, respectively. The keratinolytic protease production under optimal condition reached a maximum after 18 h of cultivation. Total amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $113.8\;{\mu}g/ml$ and $504.9\;{\mu}g/ml$, respectively. Essential amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $47.2\;{\mu}g/ml$ and $334.0\;{\mu}g/ml$, respectively. Thus, feather hydrolysates have the potential for utilization as an ingredient in animal feed.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.538-558
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• 2022

The perivascular space (PVS) of the brain, also known as Virchow-Robin space, consists of cerebrospinal fluid and connective tissues bordered by astrocyte endfeet. The PVS, in a word, is the route over the arterioles, capillaries, and venules where the substances can move. Although the PVS was identified and described first in the literature approximately over 150 years ago, its importance has been highlighted recently after the function of the waste clearing system of the interstitial fluid and wastes was revealed. The PVS is known to be a microscopic structure detected using T2-weighted brain MRI as dot-like hyperintensity lesions when enlarged. Although until recently regarded as normal with no clinical consequence and ignored in many circumstances, several studies have argued the association of an enlarged PVS with neurodegenerative or other diseases. Many questions and unknown facts about this structure still exist; we can only assume that the normal PVS functions are crucial in keeping the brain healthy. In this review, we covered the history, anatomy, pathophysiology, and MRI findings of the PVS; finally, we briefly touched upon the recent trials to better visualize the PVS by providing a glimpse of the brain fluid dynamics and clinical importance of the PVS.

• Clean Technology
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• v.27 no.4
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• pp.350-358
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• 2021

The results of this study shows that the combustor temperature ranged from 848.27 to 1,026.80 ℃, averaging about 976.61 ℃, and the NOx concentration increased as the temperature increased. The urea usage ranged from 291.00 to 693.00 kg d^-1, averaging about 542.34 kg d^-1, and the NOx concentration decreased as the urea usage increased. Residence time was about 3.38 to 9.17 s, averaging about 5.22 s, about 2.61 times larger than the 2 s of the design details. This is 1,086 kg h^-1, averaging about 55.71%, compared to the 1,950 kg h^-1 SRF input permission standard. The combustion chamber area is constant, but the residence time is shown to increase with the decrease of exhaust gas. The O₂/CO ratio was 847.05 to 14,877.34, averaging about 3,111.30, and the NOx concentration slightly increased as the O₂/CO ratio increased. As the combustor temperature and O₂/CO ratio increased, the combustion reaction with nitrogen in the air increased and the NOx concentration slightly increased. As the urea usage and residence time increased, the NOx concentration decreased slightly with an increase in reactivity with NOx. The NOx concentration at the stack ranged from 7.88 to 34.02 ppm with an average of 19.92 ppm, and was discharged within the 60 ppm emission limit value. The NOhx emission factor was 1.058 to 1.795 kg ton^-1, averaging about 1.450 kg ton^-1. This value was about 24.87% of the maximum emission factor of 5.830 kg ton^-1 of other solid fuels. Other synthetic resins and industrial wastes were 79.80% and 43.65% compared to 1.817 kg ton^-1 and 3.322 kg ton^-1, respectively. This value was similar to 1.400 kg ton^-1 of RDF in the NIER notice (2005-9), 10.98% compared to the maximum SRF of 13.210 kg ton^-1. Therefore, the NOx emission factor had a large deviation.

• Journal of Environmental Health Sciences
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• v.30 no.4
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• pp.329-343
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• 2004

We conducted to investigate citizen's attitude to the treatment of food waste in Yongin city. The respondent of $41.81\%$ throws the food waste eliminate from home and store less than 1l in Yongin. When they dump the food waste, they speak out the inconvenience of damaged envelope by animals in case of home and store. This caused troubles for reason of sanitary. So a local autonomous entity must carefully consider of expand use specially designed container as like apartment house. They give an answer that the collecting time of food waste is suitable form dawn till morning. This answer shows the satisfaction of the period time to collect the food waste. They prefer to be appointed the exclusive place to collect food waste. The service interval of collect is suitable 1 time a day. They want to increase the number of washing of the collecting container. This is good method for sanitary condition, but the care of the period time to collect the food waste is more efficient than the care of the number of washing the collecting container. The care of the period time minimizes to incur the enmity of the people and to pollute in environment. The major of respondent handled the food waste after keeping the basket or a kit. This fact shows to us almost citizen doesn't feel the seriousness to remove the moisture of the food waste. Recently, many solutions which can be disposal efficiently are getting magnified and improved owing to increase utilities channel to loss in quantities and dry the food waste. We expect the reduction of food waste is solved getting easily step by step. The results of the awareness about the facility of food waste show citizen prefer recycling facility to the other facilities. If recycle facility and incineration facility are constructed, they were worried about bed smell. When some facility of the food waste is constructed, they have to maintain and to handle not to incur the enmity of the people. The spread rate of specially designed container already increased, the citizen set a high value on the use of specially designed container more than amount-rate vinyl envelope that people have used for several years. In the cost treatment about food waste, the major respondent answered the use cost of specially designed container is suitable price. So we can know the use charge is proper level. The majority of citizen more prefer autonomous plan which voluntary atmosphere creation and public information by mass media than levy system and rising treatment cost which forced plan. The citizens have pretty positive thinking of incineration, so the government needs more efforts for a public notice, which includes the incineration is no more than abandoned thing. Each of local self government has to sort the food waste and make kind of resource system related to collecting and carrying, constructing a suitable facility, proper disposal of the food waste and producing harmless in our surrounding in order to solve the invisible problems. To do above mentioned things, we have to analyze referred several problems till now. Also, to minimize the side effect, the government will have to improve through enforce the system.

• Journal of the Korean Electrochemical Society
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• v.17 no.2
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• pp.111-118
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• 2014

The electrochemical properties using the cells assembled with the synthesized $LiCoO_2$(LCO) were evaluated in this study. The LCO was synthesized from high-purity cobalt sulfate($CoSO_4$) which is recovered from the cathode scrap in the wastes lithium ion secondary battery(LIB). The leaching process for dissolving the metallic elements from the LCO scrap was controlled by the quantities of the sulfuric acid and hydrogen peroxide. The metal precipitation to remove the impurities was controlled by the pH value using the caustic soda. And also, D2EHPA and $CYANEX^{(R)}272$ were used in the solvent extraction process in order to remove the impurities again. The high-purity $CoSO_4$ solution was recovered by the processes mentioned above. We made the 6 wt.% $CoSO_4$ solution mixed with distilled water. And the 6 wt.% $CoSO_4$ solution was mixed with oxalic acid by the stirring method and dried in oven. $LiCoO_2$ as a cathode material for LIB was formed by the calcination after the drying and synthesis with the $Li_2CO_3$ powder. We assembled the cells using the $LiCoO_2$ powders and evaluated the electrochemical properties. And then, we confirmed possibility of the recyclability about the cathode materials for LIBs.

• Proceedings of The Korean Society of Health Promotion Conference
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• 2004.10a
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• pp.1-16
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• 2004

This paper considers the possibilities of health promotion from the following perspectives; (1) IUHPE, (2) socio-cultural similarities, (3) action research, and (4) learning from our past. 1. The IUHPE values decentralized activities through regions, and countries such as Japan, Korea, Hong Kong, Taiwan and China belong to NPWP region. Since IUHPE World Conference was held in Japan in 1995, Japan used to occupy more than 60% of NPWP membership. After 2001, membership is increasing rapidly in Chinese speaking sub-region. The transnational collaboration is still in its beginning phase. 2. Confucianism is one of key points. Confucian tradition should not be seen only as obstacles but as advantages to seek a form of health promotion more acceptable in East Asia. 3. Within the new public health framework, people are expected to create and live their health. However, especially in Japan, the tendency of 'lacking of face-to-face explicit interactions' is still common at health-promotion settings as well as academic settings. Therefore, the author tried participatory approaches such as asking WlFY (interactive questions designed for subjects to review their daily life and environment) and as introducing round table interactions. So far, majority of participants welcome new trials. 4. The following social phenomena are comparatively discussed after Japanese invasion and occupation of Korea ended in 1945; ·status of oriental medicine, ·separation of dispensary services, and ·health promotion specialist as a national license. In contrast to Japanese' tendency of maintaining the status quo and postponing of substantial social change, trend toward rapid and dynamic social changes are more commonly observed in Korea. Although all of above possibilities are still in their beginning stages, they are going to offer interesting directions waiting for further challenges and accompanying researches.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.633-638
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• 2017

The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual ($10{\mu}Sv/y$) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard.