• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.57-64
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• 1999

The purpose of this study is to establish effective conditions for controlling $CH_4$, $N_2O$ emission from organic Waste / wastewater treatment processes. Continuous and batch experiments were conducted to treat the micro algae from polluted and eutrophicated lakes through the thermophilic oxic process. The microalgae used were mainly Microcystis sp.(collected from eutrophic lake) and Chlorella sp. (cultured in laboratory) Wasted cooking oil was added by aid-heating source. Physico-chemical components of sludges and microalgae were analyzed. In batch experiments, air supply was changed from 50ml/min to 150ml/min. The temperature. water content and drained water were affected by the air flow rate at initial stage. However, there was almost no influence of air flow rate on them in middle and last stages. At air flow rate of 100ml/min, the degradation rate of organic material was higher than that at other air flow rates. $CO_2$ concentration in exhaust was proportional to the strength of aeration, especially at initial stage when degradation was active. $CH_4$ with low concentration was detected only at starting stage when air diffusion was not enough. $N_2O$ production was not affected by variation of air supply. In continuous experiments no matter what the dewatering methods (with PAC and without PAC) and media (wood chip and reed chip) were changed, $N_2O$ was almost not affected by variation of injected air. Result showed that the reed chips using for lake purification could be used as media for thermophilic oxic process in lake and marshes area. $CO_2$ concentration was not so much affected by the change of dewatering methods and media types. $CH_4$ was not detected in the experimental period. So it can be shown that the thermophilic oxic process had been well operated in wide handling conditions regardless of media and dewatering methods.

• Progress in Medical Physics
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• v.10 no.1
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• pp.23-32
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• 1999

Combined MRI and Relaxogram approach was introduced as a very useful tool for fat study. The phantoms simulating homogeneous mixture of fat and non-fat environments were measured with spin echo pulse sequence on a 0.15 T whole body imager. From 45 scans, the Tl values were obtained by fitting the data to continuous distribution (CONTIN) of relaxation time. This relaxogram gives broad distributions of relaxation time, which are characterized by a number of peaks with characteristic T1 values. Two distinct peaks in relaxogram were observed and identified as signals from com oil and gelatin gel. This model system can be served as simulating the distribution of fat in muscle. Also the relative ratio of two components, which is proportional to the area under the peak, is estimated and compared to nominal values. Based on the good agreement between two predictions, the values from our proposed method agreed with nominal values within $\pm$7 % error. The effects of different concentration of contrast agent and different region of interest are presented. To optimize total scan times, the minimum required data points and so further reduction in total scan times are discussed.

• Journal of Conservation Science
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• v.24
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• pp.75-83
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• 2008

In order to assess antifungal activity of a wooden storage box, which was made of Paulownia tomentosa and used for keeping ancient documents, antifungal activity of volatile organic compounds emitted from the box was investigated along with qualitative analysis on major substances of the compounds. After collecting floating microorganisms inside air tester, the fungal activity was assessed by counting the number of colonies growing on TSA media. Compared to the control which collected 85 colonies from outdoor, 72 colonies were observed showing reduction rate of 14.82%. Through GC/MS and TDS system analysis, limonene was detected from the volatile organic compounds as characteristic features. When the fungal activity was assessed through fumigation by adding natural biocide BI and BII containing eugenol and anethole as major substances, both biocides showed a strong fungal activity with respectively 92.6%(inside the box) and 99.9%(outdoor) of reduction rate. Although these results didn't clarify antifungal activity of the volatile organic compounds emitted from the Paulownia-wood storage box and their functional components, it was at least confirmed that there is application possibility of natural biocide to use for preservation of ancient documents with increased efficiency in controlling pests of wooden storage boxes.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.394-400
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• 2004

To investigate the efficacy of alternatives to antibiotics, the present study was conducted to compare the effects of antibiotic, lactic acid, a blend of commercial essential oils (EOs) and EOs in combination with lactic acid on growth performance and the functional activity of the gut in broiler chickens. A total of 168 broiler chickens were given the basal diet supplemented with 10 ppm colistin (T1), 0.1% lactic acid (T2), 25 ppm EOs (T3), 25 ppm EOs+0.1% lactic acid (T4), 50 ppm EOs (T5) or 50 ppm EOs+0.1% lactic acid (T6) in the period 3 to 35 days of age. As a result, the broiler chickens assigned to T4 group throughout the experimental period had apparently (p<0.05) greater body weight and total gain than these assigned to T1, T2, T3 and T5 groups. However, there was no difference in growth performance among the birds fed the diets supplemented with antibiotic (T1), lactic acid (T2) and EOs (T3 and T5) alone. The weights of digestive organs and the number of lactobacilli and E. coli in the lower ileum were not affected by dietary treatments. Total trypsin activity was significantly (p<0.05) greater in T4 than T1, T2, T3 and T5 groups. Total and specific pancreatic $\alpha$-amylase activities were significantly (p<0.05) enhanced in the broiler chickens fed T4 diet compared with these fed T1, T2 and T3 diets. However, there were no differences in growth performance and digestive enzyme activities including pancreatic trypsin and $\alpha$-amylase between T4 and T6 groups fed the diets supplemented with either low or high EOs levels in combination of lactic acid. In conclusion, a blend of commercial EOs combined with lactic acid showed significant increases in digestive enzyme activities of the pancreas and intestinal mucosa, leading to increase in growth performance.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.246-252
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• 2015

In steel factory, hot roller cleaning process produces a lot of iron oxide particles called as mill scale. Major components of these particles are wustite (FeO), magnetite ($Fe_3O_4$), and hematite ($Fe_2O_3$). In this study, we tried to produce pure magnetite from the mill scale because of the largest phosphate adsorption capacity of the magnetite. The mill scale was treated with acid (HCl+$H_2O_2$), base (NaOH), and acid-base ($H_2SO_4$+NaOH). Batch adsorption tests showed the acid and/or base treatment could increase the phosphate adsorption capacity of the iron oxides from 0.28 to over 3.11 mgP/g. Magnetite, which could be obtained by acid and base treatment of the mill scale, showed the best adsorption capacity. From the kinetic analysis, both Freundlich and Langmuir isotherm well described the phosphate adsorption behavior of the magnetite. In Langmuir model, maximum phosphate adsorption capacity was found to be 5.1 mgP/g at $20^{\circ}C$.

• Korea-Australia Rheology Journal
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• v.20 no.3
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• pp.175-184
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• 2008

Chemical engineering (ChE) was conceived at the close of the 19th century as a new discipline which was designed to support then the newly-emerging industries, oil and petrochemical, by supplying the competent engineers equipped with the pertinent engineering fundamentals and skills. It helped the said industries meet the various demands and ramifications of the new pattern of the human civilization spurred by the advent of automobile transportation at the turn of the 20th century. Now ChE once again is ready to fulfill its societal responsibility as probably the most important discipline and profession in sustaining the $21^{st}$ century human civilization providing the needed engineers (ChErs) and technologies. In this study, it is attempted to analyze the role of ChE and ChErs in this context, focusing on the macroeconomic connections embedded in the discipline that allow us to envision the big pictures of the 21st century civilization where the wellbeing of the mankind invariably hinges on five essential industries, i.e., medical, pharmaceutical, energy, environment and materials. It can be argued that ChE is the only discipline that can encompass simultaneously all those five industries indispensable to sustain the 21 st century human civilization that can be termed the era of "enjoy-healthy-living-longer". It is also believed that the historical mission ChE and ChErs are supposed to fulfill now is even bigger than that they took on a hundred years ago and subsequently accomplished with remarkable success in food, clothing, shelter and entertainment industries introducing various technological innovations. The macroeconomic viewpoints are called upon in this study as were in the 2006 article (Hyun, 2006) but focusing on ChE and ChErs this time to view the connections embedded in ChE as the essential components in understanding the historical nature of the role and responsibility of ChE and ChErs. The new paradigm for ChE is also pondered over together with the frequently-cited technology concepts such as IT, BT, NT, ET and ST which are regarded intimately germane to the characteristics and perspectives of the $21^{st}$ century civilization.

• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.121-133
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• 2014

Block copolymers including ABA triblock architectures are useful as thermoplastic elastomers and toughened plastics depending on the relative glassy and rubbery content. These materials can be blended with other polymers and utilized as additives, toughening agents, and compatibilizers. Most of commercially available block copolymers are derived from petroleum. Renewable alternatives are attractive considering the finite supply of fossil resources on earth and the overall economic and environmental expenses involved in the recovery and use of oil. Furthermore, tomorrow's sustainable materials are demanding the design and implementation with programmed end-of-life. The present review focuses on the preparation and evaluation of new classes of renewable ABA triblock copolymers and also emphasizes on the use of carbohydrate-derived poly(lactide) or plant-based poly(olefins) having a high glass transition temperature and/or high melting temperature for the hard phase in addition to the use of bio-based amorphous hydrocarbon polymers with a low glass transition temperature for the soft components. The combination of multiple controlled polymerizations has proven to be a powerful approach. Precision-controlled synthesis of these hybrid macromolecules has led to the development of new elastomers and tough plastics offering renewability, biodegradability, and high performance.

• Journal of the Korean Society of Food Culture
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• v.20 no.2
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• pp.186-193
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• 2005

The antioxidative and antimicrobial activities were carried on the leeks (Allium tuberosun R.) ethanol extracts in order to find out new food functional components. Three species of leeks used in this study were Chinese leek(long type, LL), general leek(medium type, LM), and medicinal leek (short type, LS). Total amounts of polyphenol compounds in LS was shown as the highest (436.60mg%) value. All of ethanol extracts of these leeks were shown to be had good electron donating ability(EDA) and nitrite scavenging activity. Specialty, the ethanol extract of LS(LSEx) had the highest EDA 30.47% and nitrite scavenging activity 77.24% and the lowest was LMEx. The antioxidative activities of these ethanol extracts on the corn germ oil were measured by peroxide values(POV) and conjugated diene values (CDV) storaging for 30 days at $60{\pm}2^{\circ}C$. The antioxidative activities of these extracts by POV and CDV were determined as following order as LSEx> LLEx) LMEx. The antioxidative activities of all extract were presented as high tendency by increasing adding amounts (0.02%>0.05%>0.1%). When the antioxldative activities were compared with BHT and ${\alpha}-tocopherol$, the degree of the antioxidative activities of these extracts were certified as lower than BHT and higher than ${\alpha}-tocopherol$. And also LSEx, LMEx, and LLEx had antimicrobial effects on the several micro organisms, especially the effect on the Pseudomonas aeruginasa was remarkable. While LMEx had shown inhibit effect on most of micro organism used in this study.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.254-259
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• 1992

The processing conditions and food components of meaty textured sardine burgers were studied to develope a new form of burger, The separated sardine meat was chopped, mixed with 14.1% emulsion curd, 1.5% table salt, 2.0% sugar, 0.4% sodium bicarbonate, 0.2% polyphosphate, 0.1% monosodium glutamate, 8.0% bread powder, 0.4% onion powder, 0.1% garlic powder, 0.1% ginger powder and 3.0% soybean protein by remodeled stone mortar. This seasoned sardine meat was fried in soybean oil $(165{\pm}2^{\circ}C,\;3min)$. The main fatty acids of sardine burger were palmitic acid, oletic, acid, linoleic acid, eicosapentaenoic acid and docosahexaenoic acid. Amino acid composition of sardine burger were mainly consisted of histidine, glutamic acid, leucine and lysine. The major taste compounds in the product were revealed nucleotides and their related compounds $(11.19{\sim}11.96\;{\mu}mole/g)$ such as IMP and free amino acids (1824.8 mg/100g) such as histidine, glutamic acid, leucine and lysine. Total creatinine, betaine and trimethylamine oxide were seemed to act an auxiliary role in taste of product.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.467-473
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• 2012

Coenzyme Q10 (CoQ10) is a natural lipid cofactor with antioxidant and anti-aging properties as cosmetic and food ingredients, involved in cellular energy metabolism. Here, nano-emulsions with CoQ10 were fabricated with lecithin, ethanol, oil, and sorbitan monostearate (Arlacel 60), as major components. Phase inversion emulsion method with ultrasonicator was utilized in producing CoQ10 solution, and stabilization effects from lecithin and ethanol and other diverse perturbation factors were evaluated over time. Physical properties of the emulsion were characterized such as its size, surface charges by zeta-potential, and the overall structures. Optimal concentrations of CoQ10 and Arlacel 60 were 0.8% and 3%, respectively, for producing the smallest sizes of nanoemersions in a 100 nm diameter with best morphology. No notable changes in the size were observed over 7 days from Ostwald ripening, when the concentration of Arlacel 60 was higher than 2%. Even after 270 days at room temperature, the size of nanoemulsions maintained as 115 nm in diameter, revealing only a 10% increase with high degrees of long termed stability and substantiality. In addition, changes in the surface potential occurred possible due to the flocculation effect on the nanoparticles.