• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.666-671
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• 2012

Gas hydrates are inclusion compounds formed when small-sized guest molecules are incorporated into the well defined cages made up of hydrogen bonded water molecules. Since large masses of natural gas hydrates exist in permafrost regions or beneath deep oceans, these naturally occurring gas hydrates in the earth containing mostly $CH_4$ are regarded as future energy resources. The heat of dissociation is one of the most important thermal properties in exploiting natural gas hydrates. The accurate and direct method to measure the dissociation enthalpies of gas hydrates is to use a calorimeter. In this study, the high pressure micro DSC (Differential Scanning Calorimeter) was used to measure the dissociation enthalpies of methane, ethane, and propane hydrates. The accuracy and repeatability of the data obtained from the DSC was confirmed by measuring the dissociation enthalpy of ice. The dissociation enthalpies of methane, ethane, and propane hydrates were found to be 54.2, 73.8, and 127.7 kJ/mol-gas, respectively. For each gas hydrate, at given pressures the dissociation temperatures which were obtained in the process of enthalpy measurement were compared with three-phase (hydrate (H) - liquid water (Lw) - vapor (V)) equilibrium data in the literature and found to be in good agreement with literature values.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.161-168
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• 2014

This study aimed to investigate dietary concentrate:forage ratios (C:F) and undegraded dietary protein (UDP) on nitrogen balance and urinary excretion of purine derivatives (PD) in lambs. Four Dorper${\times}$thin-tailed Han crossbred castrated lambs with $62.3{\pm}1.9$ kg body weight at 10 months of age were randomly assigned to four dietary treatments in a $2{\times}2$ factorial arrangement of two levels of C:F (40:60 and 60:40) and two levels of UDP (35% and 50% of CP), according to a complete $4{\times}4$ Latin-square design. Each experimental period lasted for 19 d. After a 7-d adaptation period, lambs were moved into individual metabolism crates for 12 d including 7 d of adaption and 5 d of metabolism trial. During the metabolism trial, total urine was collected for 24 h and spot urine samples were also collected at different times. Urinary PD was measured using a colorimetric method and creatinine was measured using an automated analyzer. Intake of dry matter (DM) (p<0.01) and organic matter (OM) (p<0.01) increased as the level of UDP decreased. Fecal N was not affected by dietary treatment (p>0.05) while urinary N increased as the level of UDP decreased (p<0.05), but decreased as dietary C:F increased (p<0.05). Nitrogen retention increased as dietary C:F increased (p<0.05). As dietary C:F increased, urinary excretion of PD increased (p<0.05), but was not affected by dietary UDP (p>0.05) or interaction between dietary treatments (p>0.05). Daily excretion of creatinine was not affected by dietary treatments (p<0.05), with an average value of $0.334{\times}0.005$ mmol/kg $BW^{0.75}$. A linear correlation was found between total PD excretion and PDC index ($R^2$ = 0.93). Concentrations of creatinine and PDC index in spot urine were unaffected by sampling time (p>0.05) and a good correlation was found between the PDC index (average value of three times) of spot urine and daily excretion of PD ($R^2$ = 0.88). These results suggest that for animals fed ad libitum, the PDC index in spot urine is effective to predict daily excretion of PD. In order to improve the accuracy of the spot sampling technique, an appropriate lag phase between the time of feeding and sampling should be determined so that the sampling time can coincide with the peak concentration of PD in the urine.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.1
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• pp.119-132
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• 2014

This study analyzed the failure prediction model of the firms listed on the KOSDAQ by considering whether there are embezzlement, malpractice and the largest shareholder changes or not. This study composed a total of 166 firms by using two-paired sampling method. For sample of failed firm, 83 manufacturing firms which delisted on KOSDAQ market for 4 years from 2009 to 2012 are selected. For sample of normal firm, 83 firms (with same item or same business as failed firm) that are listed on KOSDAQ market and perform normal business activities during the same period (from 2009 to 2012) are selected. This study selected 80 financial ratios for 5 years immediately preceding from delisting of sample firm above and conducted T-test to derive 19 of them which emerged for five consecutive years among significant variables and used forward selection to estimate logistic regression model. While the precedent studies only analyzed the data of three years immediately preceding the delisting, this study analyzes data of five years immediately preceding the delisting. This study is distinct from existing previous studies that it researches which significant financial characteristic influences the insolvency from the initial phase of insolvent firm with time lag and it also empirically analyzes the usefulness of data by building a firm's fail prediction model which considered embezzlement/malpractice and the largest shareholder changes as dummy variable(non-financial characteristics). The accuracy of classification of the prediction model with dummy variable appeared 95.2% in year T-1, 88.0% in year T-2, 81.3% in year T-3, 79.5% in year T-4, and 74.7% in year T-5. It increased as year of delisting approaches and showed generally higher the accuracy of classification than the results of existing previous studies. This study expects to reduce the damage of not only the firm but also investors, financial institutions and other stakeholders by finding the firm with high potential to fail in advance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.337-348
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• 2012

The Yellow Sea Ecoregion Conservation Project is a joint international project which is carried out under the purposes of conserving the habitats in the Yellow Sea Ecoregion and biodiversity from various threats that damage ecosystems, informing the importance and value of the Yellow Sea Ecoregion, and promoting the understanding and interests of Korea, China and Japan. Subsequent to the Yellow Sea Ecoregion Planning Programme which had been performed during the period from 2002 to 2006, the Yellow Sea Ecoregion Support Project has been performed over 7 years in total from 2007 to 2014. Panasonic is sponsoring the financing of the project, and the organizations in charge of the project by country are Korea Institute of Ocean Science & Technology for Korea and World Wide Fund for Nature branches for China and Japan. While the Yellow Sea Ecoregion Planning Programme was focused on the biological assessment and the selection of potential priority area by scientific review, the Yellow Sea Ecoregion Support Project is oriented toward practical activities targeting more diversified stakeholder. Especially, this project plans to support direct conservation activities in the region and participation and cooperation from local residents. The project plan is comprised of 3 phases. During the first period from 2008 to 2009, small grant projects were operated targeting 16 institutions of Korea and China, and for the second period from 2010 to 2012, one place each was selected as demonstration site for habitat conservation in Korea and China respectively and supported for three years to introduce the conservation method based on international standards such as the management of marine protected areas, ecosystem-based management and community-based management and simultaneously to develop habitat conservation activities suitable for national and regional characteristics. During the period from 2013 to 2014 which is the last phase, the project plans to distribute the performance of small grant projects and demonstration site activities through a series of forums among stakeholder. Through the activities described above, the recognition of general public on the conservation of the Yellow Sea Ecoregion was changed positively, and community-based management began to be reflected in the policies for the marine protected areas of central and local government.

• Journal of The Korean Association For Science Education
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• v.34 no.5
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• pp.499-510
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• 2014

The purpose of this research is to understand interactive learning during docent-led tours in a science museum focusing on scaffolding. We developed a scaffolding framework by collating the work of other researchers in related fields. The results show that scaffolding included three dimensions: purpose, interaction, and domain. The purpose dimension, divided into six categories, is related to the intention of the scaffolder and what the scaffolding are for: strategic, social, procedural, conceptual, verbal, and metacognitive. The interaction dimension reflects students' interaction with the scaffolder in two ways: dynamic (situation specific) and static (planned in advance). The domain dimension is related to two contents: domain-general and domain-specific (such as science). The scaffolding framework was applied to dynamic interactions between docents and visitors. The data was collected from elementary school students' family visits with the guidance of two docents at the Seodaemun Museum of Natural History. The data collected consisted of surveys, interviews, video-recordings, and transcripts. The analysis shows that five guiding contexts and scaffolding phases were recognized; 1) strategic scaffolding in a poorly illustrated exhibit; 2) conceptual scaffolding in a thoroughly explanative exhibit; 3) verbal scaffolding in misleading interpretation; 4) procedural scaffolding in a manipulative exhibit; and 5) metacognitive scaffolding with inaccurate content. In addition, the results show that the docents used the dynamic and static scaffolding synthetically so that the docent-led tour was effective. In conclusion, this study presents the usefulness of understanding visitors' science learning through the scaffolding framework, as well as the how docents can scaffold actively.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.388-394
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• 2014

BACKGROUND: Aclonifen is used as a systemic and selective herbicide to control a wide spectrum broad-leaf weeds by inhibition carotenoid biosynthesis, and then its MRLs(Maximum Residue Limits) will be determined in onion and garlic. In this study, a new official method was developed for aclonifen determination in agricultural products to routinely inspect the violation of MRL as well as to evaluate the terminal residue level. METHODS AND RESULTS: Aclonifen was extracted from crop samples with acetone and the extract was partitioned with dichloromethane and then purified by silica solid phase extraction(SPE) cartridge. The purified samples were detected GC using an ECD detector. Limits of detection(LOD) was 0.001 mg/kg and quantification(LOQ) was 0.005 mg/kg, respectively. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$, n=5). The recoveries were ranged from 74.3 to 95.0% with relative standard deviations(RSDs) of less than 8%. All values were consistent with the criteria ranges requested in the Codex guidelines(CAC/GL 40). CONCLUSION: The proposed analytical method was accurate, effective and sensitive for aclonifen determination and it will be used to as an official method in Korea.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.247-251
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• 2013

The objective of present study was to develop a simultaneous determination method of 5 medical compounds, including beclomethasone, dexamethasone, prednisolone, ketoprofen, phenylbutazone in foods, using LC-MS/MS. To optimize MS analytical condition of 5 compounds, each parameter was established by MRM mode. The chromatographic separation was achieved on a C18 column successfully, with a mobile phase made up of A (0.1% formic acid) and B (0.1% formic acid in acetonitrile), at a flow rate of 0.3 mL/min for 17 min with a gradient elution. LOD and LOQ of 5 compounds were in the range of 0.40~4.60 ng/mL and 0.81~11.46 ng/mL, respectively. As a result of analyzing the three concentrations of the standard mixture added to blank samples, the results showed that the mean recovery rate of 5 compounds was in the range of 81.52~103.83%, and RSD (%) of Intra- and Inter-day assay were 0.52-10.45. Since relatively fine selectivity, accuracy and reproducibility were shown in this qualified experimental method, it could be utilized efficiently to investigating those 5 compounds to see if it is added to food products illegally.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.16-24
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• 2011

A method was established for the simultaneous determination of sugar alcohols, erythritol, xylitol, sorbitol, inositol, mannitol, maltitiol, lactitol and isomalt by High Performance Liquid Chromatography (HPLC). The sugar alcohols were converted into strong ultraviolet (UV)-absorbing derivatives with p-nitrobenzoyl chloride (PNBC). HPLC was performed on Imtakt Unison US-$C_18$ column, using acetonitrile: water (77:23) as a mobile phase and UV detection (260 nm). The calibration curves for all sugar alcohols tested were linear in the 10~200 mg/L range. The average recoveries of the sugar alcohols from three confectioneries spiked at 100 ppm of eight sugar alcohol standards ranged from 81.2 to 123.1% with relative standard deviations ranging fromo 0.2 to 4.9%. The limits of detection (LODs) were $0.5{\sim}8\;{\mu}g/L$ and the limits of quantification (LOQs) were $2{\sim}17\;{\mu}g/L$. Reproducibility of 8 sugar alcohols was 0.28~1.97 %RSD. The results of the analysis of confectioneries showed that 89 samples of 130 were detected and the sugar alcohols content of samples investigated varied between 0.4 and 693.7 g/kg. A method for the simultaneous determination of eight sugar alcohols will be used as basic data for control of sugar alcohols in confectioneries, and quality control in food manufacturing.

• Korean Journal of Environmental Agriculture
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• v.14 no.2
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• pp.186-201
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• 1995

In order to elucidate the fate of the residues of the pyrethroid acaricide-insecticide, acrinathrin in soil, maize plants were grown for one month on the specially-made pots filled with two different types of soils containing fresh and one-month-aged residues of [$^{14}C$]acrinathrin, respectively. The mineralization of [$^{14}C$]acrinathrin to $^{14}CO_2$ during the one-month period of aging and of maize cultivation amounted to $23{\sim}24%$ and $24{\sim}33%$, respectively, of the original $^{14}C$ activities. At harvest after one-month growing, the shoots and roots contained less than 0.1% and 1% of the originally applied $^{14}C$ activity, respectively, whereas the $^{14}C$ activity remaining in soil was $65{\sim}80%$ in both soils. Three degradation products with m/z 198(3-phenoxybenzaldehyde), m/z 214(3-phenoxybenzoic acid), and m/z 228(methyl 3-phenoxybenzoate) besides an unknown were identified from acetone extracts of both soils without and with maize plants after treatment of [$^{14}C$]acrinathrin, by autoradiography and GC-MS, and those with m/z 225(3-phenoxybenzaldehyde cyanohydrin) and m/z 198 (3-phenoxybenzaldehyde) from acetone extract of the Soil A treated with 50 ppm acrinathrin and grown with maize plants for 30 days were identified by mass spectrometry. These results suggested that the hydrolytic cleavage of the ester linkage adjacent to the $^{14}C$ with a cyano group, forming 3-phenoxybenzaldehyde cyanohydrin. The removal of hydrogen cyanide therefrom leads to the formation of 3-phenoxybenzaldehyde as one of the major products. The subsequent oxidation of the aldehyde to 3-phenoxybenzoic acid, followed by decarboxylation would evolve $^{14}CO_2$. Solvent extractability of the soils where maize plants were grown for 1 month and/or [$^{14}C$]acrinathrin was aged for 1 month was less than 31% of the original $^{14}C$ activity and over 95% of the total $^{14}C$ activity in soil extracts was distributed in the organic phase. Accordingly, acrinathrin turned out to be degraded rapidly in both soils and be bound to soil constituents as well, not being available to crops.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.159-164
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• 2009

Purpose: The automatic notification system for alarm values on blood tests conducted by this hospital is designed to immediately inform the attending physician of the result of a blood test, to help the relevant patient to promptly receive proper treatment, and furthermore, to reduce the likelihood of a fatal influence to the patient. From 2004, the clinical pathology department of this hospital has been operating an automatic notification system for blood tests, in relation to the items of WBC, Hb, Plt, PB cell morphology, Malaria, PT, aPTT, BT, fibrinogen, Ca, K, Na, Cl, Mg, Glucose, Ketone, Digoxin, PKU, Homocystinuria, 17-OHP, Neonatal TSH, and Galactosemia. Recently, the blood test room of the nuclear medicine department has been operating an automatic notification system for the alarm values of a blood test, in relation to three items of TSH, FT4, and 17-${\alpha}$-OH-PGR, and the details of its operation will be described here. Materials and Methods: The subjects were newborn babies that were receiving TSH, FT4, and $17{\alpha}$-OH-PGR prescriptions from February $19^{th}$ to May $11^{st}$, 2009, and who met with the following criteria: N2340 Thyroid-Stimulating Hormone: >$10{\mu}IU/mL$ (Reference value: 0.4~5.0). N2360 Free-Thyroxine: <$0.8{\mu}g/dL$ (Reference value: 0.8~1.9), N2444 $17{\alpha}$-OH-Progesterone: >$30\;{\mu}g/mL$ (Reference value: Male (0.6~3.42), Female follicular phase (0.19~1.8). The automatic notification system was operated by entering test items, relevant treatment departments, and standard values for reporting alarm values into the OCS program, and then transmitting results that met with the input conditions to the PDAs of the prescription and the attending physician by SMS. Results: Reporting an alarm value of the nuclear medicine blood test, which can have a fatal influence on the lives of patients, will help cure patients, improve the quality of the test, and furthermore, will increase the patient's satisfaction with the prescription and treatment of the test.