• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.310-315
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• 1999

The feasibility of an absorbent biofilter system was examined for rural wastewater treatment. Hydraulic loading rates varied from 50 to 250 cm/day. Effluent of the septic tank was fed into the absorbent biofilter, and small ventilation fan was provided to supply air at the rate of 250 L/min to aerate the biofilter. The biofilter system demonstrated high removal rates for $BOD_5$ and TSS at the loading rate of 150 cm/day, generally meeting the Korean effluent water quality standard of 20 mg/L applicable to both. The nutrient removal was less satisfactory than the results of $BOD_5$ and TSS, but it was within the expected range of biological treatment processes. Considering the abnormally high influent concentration of nutrients during the experiment, better performance results could have been obtained if ordinary domestic wastewater was used. The system performance was not significantly affected by the hydraulic loading up to 150 cm/day, which is far more than the loading limit of the sand filter systems. Maintenance requirement was minimal, and no problems with noise, odor, flies or sludge arose. Since the biofilter system can be operated at a distance, operation in remote rural area and multi-system connected to one control office might be advantageous to the rural area. Overall, considering the cost-effectiveness, stable performance, and minimum maintenance, the biofilter system was thought to be a competitive alternative to treat wastewater in Korean rural communities.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.156-168
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• 2012

Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

• New & Renewable Energy
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• v.9 no.4
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• pp.40-50
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• 2013

This study was performed to investigate the potential of torrefied tulip tree (TT) for the production of pellets. For this purpose, chemical composition and fuel characteristics of torrefied TT were examined. In addition, pellets were fabricated by using sawdust of torrefied TT chip, and durability of the pellet was measured. Lignin content of torrefied TT was higher than that of non-torrefied TT, and increased with the increases of torrefaction temperature and time. Fuel characteristics of torrefied TT were affected by torrefied conditions, and the characteristics were influenced more by torrefaction temperature than by torrefaction time. Higher heating value (HHV) and ash content (AC) of torrefied tulip tree increased with increasing torrefaction temperature, and the values were much higher than HHV and AC values of non-torrefied TT. Durability of pellets fabricated with $230^{\circ}C$- and $250^{\circ}C$-torrefied TT was higher than that of $270^{\circ}C$-torrefied TT, and the value exceeded the minimum requirement (-97.50%) of the 1st-grade pellet standard designated by Korea Forest Research Institute. Based on the results, torrefaction treatment of $250^{\circ}C/50min$ to TT might be a optimal condition for the production of TT pellets considering the mass balance and fuel characteristics of TT as well as the durability of the pellets. Thus, it is confirmed that torrefied TT can be used as a raw material for the production of bio-pellets.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.146-164
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• 2024

Owing to the residual toxicity and adverse health effects of chemical preservatives, there is an increasing demand for using natural preservatives in food. Although many natural extracts have been evaluated, research on their antibacterial effects remains insufficient. Therefore, this study aimed to explore the possibility of developing Psidium guajava, Ecklonia cava, and Paeonia japonica (Makino) Miyabe & Takeda extracts as natural food preservatives. Further, the effect of mixing these extracts on microbial growth and quality was evaluated during the refrigeration of sausages. Optimal mixing ratios were determined based on the minimum inhibitory and bactericidal concentrations of each mixed extract against the Listeria monocytogenes, Salmonella spp. and Escherichia coli. D-optimal mixing design optimization tool was further used to obtain an optimum mixing ratio of Formulation 1 (F1). The antibacterial activity of F1 increased with increasing concentration, with similar activities at 0.5% and 1%. The sausages with synthetic or natural preservatives showed significantly lower lipid oxidation than those of the control and grapefruit extract-treated sausages after 4 wk of refrigeration. Total plate counts were observed only in the control and treatment groups stored for 3 wk, and no significant effect of ascorbic acid was observed. Compared to the other samples, sausages with added natural extracts showed the highest overall acceptability scores initially and after 4 wk. Therefore, similar amounts of grapefruit seed and natural extracts had the same effect on microbiological analysis and lipid rancidity during sausage storage. Hence, this mixture can serve as a potential natural preservative in meat products.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.37-41
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• 2016

Purpose The importance of quality control by the error to a minimum, which for the purpose of enhancing the reliability of the examination is not be emphasized excess. Currently, most nuclear medicine laboratory are conducting the internal and external quality control, and they are applying the Levey-Jennings or Westgard Multi-Rules by using the commercialized quality control materials. The reliability of the nuclear medicine blood test which affects the diagnosis of patients and the treatment policy is being secured through this quality control activity. Therefore, researchers will evaluate the utility of the statistic quality control using the population distribution of the nuclear medicine blood test conducted targeting the checkup examinees by the additional technique of the reliability improvement. Materials and Methods A statistic analysis was performed about 12 items of the nuclear medicine blood test targeting 41,341 peoples who used the health screening and promotion center in Asan Medical Center from January, 2014 to December, 2014. The results of 12 items of the nuclear medicine blood test was divided into the monthly percentage of three groups: within reference values, over reference, and under reference to analyze the average value of the population distribution, standard deviation, and standard deviation index (SDI). Results The standard deviation of the population distribution mostly showed a result within ${\pm}2SD$ in all groups. However, When the standard deviation of the population distribution represented a result over ${\pm}2SD$, it was confirmed SDI was showing a result of SDI > -2 or SDI > 2. As a result of analyzing the population distribution of 12 items(AFP, CEA, CA19-9, CA125, PSA, TSH, FT4, Anti-Tg-Ab, Anti-TPO-Ab, Calcitonin, 25-OH-VitD3, Insulin) of the nuclear medicine blood part basic test, when SDI of the monthly percentage which deviated from the reference values was over ${\pm}2.0$, CA19-9 September was 2.2, Anti-Tg-Ab may was 2.2, Insulin January was 2.3, Insulin March was 2.4. It was confirmed these cases were attributed to the abnormality of the test reagent (maximum combination rate of isotope reagent declined) and the decline of the test response time. Conclusion The population distribution includes the entire attribute which becomes the study object. It is expected the statistic quality management using the population distribution which was conducted targeting the checkup examinees by dividing into three groups: within reference values, over reference, and under reference by means of this characteristics will be able to play a role of complementing the internal quality control program which is being carried out in the laboratory.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2557-2561
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• 2013

Background: Chemoradiation (CRT) using cisplatin-based regimens has become the standard of care in the treatment of squamous cell head and neck cancers (SCHNC). The impact of taxanes as radiosensitizing agents with concurrent CRT regimens is unknown. We therefore retrospectively evaluated the efficacy and tolerability of a weekly cisplatin+docetaxel combination with CRT in locally advanced SCHNC. Methods: Sixty-six patients with locally advanced SCHNC (39.4% stage IV, 53% stage III, and 7.6% stage II) were assessed retrospectively. Total radiation dose to the PTV of gross disease (primary and/or node) was 70 Gy/35 fractions, 5 fractions per week. Minimum doses of 60 Gy and 50 Gy were administered to PTVs of elective high risk and low risk disease, respectively. Chemotherapy (CT) consisted of weekly cisplatin (20 $mg/m^2$)+docetaxel (20 $mg/m^2$) concurrently with RT. Results: The median age of the patients was 58 years (range, 32-77). Objective response rate was 83.3%. The 2-year progression-free survival (PFS) and overall survival (OS) were 75.7% and 78.3%, respectively. The most common grade 3 and 4 toxicities were mucositis (36.4%), nausea and vomiting (12.1%), neutropenia (4.5%). Conclusion: Weekly cisplatin and docetaxel concurrent with RT for locally advanced SCHNC was found tolerable with high efficacy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.6
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• pp.275-281
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• 2018

Objectives: Isolated mandibular fractures contribute to approximately 45% of maxillofacial traumas. Improper management of mandibular fractures can cause myriad potential complications and can lead to serious functional and aesthetic sequelae. The objective of the study is to design a stepwise approach for managing isolated mandibular fractures using open reduction and internal fixation (ORIF) with regional anesthesia on outpatient basis. Materials and Methods: Patients with isolated mandibular fractures presenting to the department of maxillofacial surgery were selected for ORIF under regional anesthesia based on occlusion, age, socioeconomic status, general condition, habits, and allied medical ailments. Standard preoperative, intraoperative, and postoperative protocols were followed. All patients were followed up for a minimum of 4 weeks up to a maximum of 1 year. Results: Of 23 patients who received regional anesthesia, all but one had good postoperative functional occlusion. One patient was hypersensitive and had difficulty tolerating the procedure. Two patients developed an extraoral draining sinus, one of whom was managed with local curettage, while the other required hardware removal. One patient, who was a chronic alcoholic, returned 1 week after treatment with deranged fracture segments after he fell while intoxicated. Conclusion: With proper case selection following a stepwise protocol, the majority of mandibular fractures requiring ORIF can be managed with regional anesthesia and yield minimal to no complications.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.66-74
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• 1992

A method for the multiresidual simultaneous analysis of 11 thiocarbamates was studied using HPLC. Thiocarbamate in Chinese cabbage was analyzed in the order of extraction, partition, and cleanup in their optimum condition. Acetone was chosen as an extracting solvent. As a partitioning solvent, the mixture of 50% methylene chloride and petroleum ether containing extremely small water content showed good recoveries of thiocarbamate from the water layer. Partition efficiency was affected by pH of the water layer; it remained almost constant under the acidic and neutral condition while decreasing under the basic condition. The comparison done in cleanup step showed that the column chromatographic method is superior to the treatment of coagulating reagent. As an absorbent, the mixture of charcoal, magnesia, and celite with the ratio of 1 : 2 : 4 gave better recoveries and also effectively removed chlorophyll. Over the total procedure, the average recoveries for thiocarbamates in Chinese cabbage were 91% at about 2 ppm fortification level within the relative standard deviation of 8%, and the minimum detection limit (MDL) was 2.2${\sim}$9.3 ng.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.299-304
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• 2008

Starting characteristics of the axi-symmetric second throat exhaust diffuser (STED) with zero-secondary flows are numerically investigated. Renolds-Average Navier-Stokes equations with a standard ${\kappa}-{\varepsilon}$ turbulence model incorporated with enhanced wall treatment are solved to simulate the diffusing evolutions of the nozzle plume. Minimum (optimum) starting pressure difference of 20$\sim$25% between 1-D theory and the measured data validated from previous results[5] is also applied to predict the range of an effective diffuser expansion ratio (Ad/At) in this system.

• Journal of Legislation Research
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• no.55
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• pp.193-237
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• 2018

The recent surge in the ISD lawsuit filed against the Korean government is likely to cause major domestic confusion. This is because in most cases, foreign investors have claimed billions of won in damages filed against Korea in the ISD lawsuit. Public opinion will be generated to abolish the ISD lawsuit system, which is included in the international investment agreement, when a decision comes out in the Elliott/Mason case or Lone Star case, which has already been completed by the hearing. It is clear that the ISD clause, which is commonly included in most of the BITs, FTAs, can be a limiting factor in the government's public policy, as shown by many investment disputes. However, it is not necessary to have a negative view of the ISD clause itself, given that it is a system that can protect Korean investors from illegal and inappropriate actions by local governments. Since Korea already allows the system of ISD lawsuits with many countries through FTAs and BITs, and negotiations are underway to sign FTAs with new countries, the possibility that foreign investors will refer to the ISD proceeding further to our government's public policy will increase. In order to prepare for an ISD lawsuit, the Korean government has launched a response team consisting of government practitioners, private scholars, and legal professionals in the central government ministries to review major legal issues that are controversial in the cases of the ISD. In particular, local governments and public institutions, which fail to recognize the importance of international investment regulations and ISD clause, need to share and train relevant information so that all processes for public policy planning and implementation comply with international investment rules such as BITs and FTAs.