• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.238-241
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• 2010

The purification of indole from 54.3wt% indole fraction (temperature range of distillate: $250{\sim}255^{\circ}C$) recovered by extraction-distillation combination of coal tar fraction (temperature range of distillate: $240{\sim}265^{\circ}C$) was examined by solute crystallization. The feed consists of eight components such as quinoline, iso-quinoline, indole, quinaldine, 1-methylnaphthalene, 2-methylnaphthalene, biphenyl and phenyl ether. Hexane and an aqueous solution of methanol (50 : 50 vol%) were used as the crystallization solvent and the coolant, respectively. A batch stirred tank of glass material was used as a crystallization apparatus. By increasing the operation temperature and the volume ratio of solvent to feed at initial, the purity of indole increas ed, but yields of indole showed a decreasing tendency. Solute crystallization method using hexane as a solvent was excellent because the purity of 99.3 wt% indole was recovered at the yield of 50% without washing operation.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.17-22
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• 2007

The feasibility of soil washing was investigated to remediate Pb-contaminated field soil. Hydrochloric acid was used as a washing agent. As mixing time increased from 5 min to 120 min, removal efficiency of Pb from contaminated soil increased from 69.3% to 81.9%. Two times washing with 0.2 M HCl showed 96% removal efficiency even at mixing time of 10 min. The Pb content in soil increased sharply as particle size of soil decreased, and removal efficiency was highly dependent on mixing time and temperature. Based on this result, acid washing technologies can be applied to remediate the Pb-contaminated soil used in this study.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.72-77
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• 2007

Soil contamination by heavy metals was environmental concern due to its effect on human. In this study, monopotassium phosphate $(KH_2PO_4)$ used as phosphate source to remediate the contaminated soil with heavy metals and factors such as reaction time, initial concentration and pH of phosphate solution, species of heavy metal (lead, cadmium, zinc) and particle size were controlled. Heavy metals were removed in the order Pb > Zn > Cd and the maximum effectiveness was achieved for Pb. The removal efficiency of lead was from 95% to 100% and occurred rapidly occurred during 10 minutes. Mechanism of lead immobilization is dissolution of phosphate and the forming of a new mineral with phosphate having extremely low solubility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.541-550
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• 2011

This study sets the goal to improve effectively water quality of stream by complementing the weak points of the gravel contact oxidation process to use the inverted siphon curved channel system in free overfall of serial contact materials. The size of the current system can be diminished by expanding contact time, and the materials' replacement can be made easier when their gap are closed through the filtering boxes of contact materials. This system also has been developed into a construction method in which mixed and serial contact materials can be employed by using just the conventional single contact materials. It was verified the improvement ability of water quality of this system, during the simulation test at Tandong stream in Daejeon. The results of the verification of water quality improvement through several experiments in field were measured as follows : it showed to reduce about the averaged 55~83% higher than 60~75%, the internal planned goal of water quality improvement facilities.

• Fashion & Textile Research Journal
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• v.20 no.5
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• pp.600-607
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• 2018

Polypropylene fibers, while having many advantages such as light weight, sweat fast drying, water-repellent, drainage, thermal insulation, anti-static property has a drawback in dyeing. In recent years, the development of dyeable polypropylene fibers has expanded its value in the textile market. The purpose of this study is to fabricate composite spun yarns using polypropylene, acrylic, rayon and wool and to analyze tensile properties, uniformity characteristics, bending properties, hairiness, and surface shape according to the degree of fineness and blended ratio. The specimens consisted of 100% polypropylene spun yarn pp30, pp40 and ppa(pp/acrylic), ppr(pp/rayon), ppw(pp/wool), 5 altogether sed in this study. The results of the study are as follows. The breaking strength of polypropylene spun yarn blended with rayon and acrylic was higher than that of 100% polypropylene spun yarn. The polypropylene spun yarn is higher the fineness been shown to decrease the breaking strength and elongation. The bending properties of polypropylene spun yarns were in the order of ppa>ppr>pp40>pp30>ppw. The unevenness of ppw, ppr, and ppa was higher than pp40 and pp30. With the exception of ppw with crimp properties, pp30 and pp40 were found to have a hairiness index greater than ppr, ppa. In the microscopic photographs of polypropylene spun yarn, pp30, which had the highest hairiness index, was found to have a thick yarn and a large number of hairs, and ppw had hairs of 3 mm or more protruding elongated outwardly.

• Geotechnical Engineering
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• v.9 no.1
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• pp.31-44
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• 1993

Model tests in calibration chamber with open -ended steel pipe pile have been performed in sand deposit to clarify effect of soil plug on bearing capacity, load transfer mechanisms in soil plug, and behavior of soil plug under dynamic and static conditions. Model piles were devised so that bearing capacity of open -ended pile could be measured separately into outside skin friction, inside skin friction due to soil plug -pile interaction and end bearing force on the section of steel pipe pile. It may be concluded, form the test results, that the plugging level of open -ended pile is more correctily defined by specific recovery ratio, y, rather than by plug length ratio, PLR, and the major part of inside skin friction is generated within the range of three times as long as the inner diameter of the pile from the pile tip. The ratio of inside skin friction to total bearing capacity is much larger than that of outside skin friction to total bearing capacity. Therefore, the bearing capacity of pile could not be well predicted, unless the inside skin friction is properly taken into account.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.194-197
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• 2010

A 14-year-old gelded dressage horse weighing 500 kg was presented to the Equine Medical Center of the Seoul Racecourse of Korea Racing Authority (KRA) due to coughing and mucopurulent nasal discharge. The horse was initiated with empirical antibiotic in the first place. However, the clinical signs did not improve but were rather exacerbated even after 3 weeks of therapy. Extensive diagnostic procedures including transtracheal wash (TTW) fluid cytology were undertaken. The localized wheezes and crackles were auscultated and an increase in the amount of mucopurulent exudate in trachea was observed at endoscopy. Infiltration of neutrophils was observed in the TTW fluid cytology implying chronic obstructive pulmonary disease (COPD). Therefore, the systemic glucocorticoid therapy was to be given for 3 weeks with improved ventilation provided at the same time. The respiratory symptoms started to improve in 7 days of therapy and were fully resolved by when the therapy was terminated. The horse is clinically normal now and being monitored for development of any signs of chronic obstructive pulmonary disease.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.1-6
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• 2003

Abstract: In order to improve the system for biological nitrogen oxidizing process in sewage and wastewater, a bacterium having high abilities to oxidize of nitrogen was isolated from wastewater and polluted soils. The strain was identified to Bacillus sp. CH-N, based on the physiological and biochemical properties. Characteristics and oxidizing ability of both ammonia and nitrite were examined for the strain, Bacillus sp. CH-N. The strain showed the oxidizing rate about 80% to 90% on the sewage and wastewater after 48 h culture. The nitrogen oxidizing rate was increased in proportion to the initial concentration of glucose. The microorganism, Bacillus sp. CH-N cell immobilized on ceramic carrier were evaluated for the oxidation of ammonia in culture media.

• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.275-282
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• 2010

Chloroplast transformation in higher plants offers many attractive advantages over nuclear transformation, including a high-level accumulation of foreign proteins, multi-gene expression in single transformation event via transgene stacking in operons and no position effect due to site-specific integration of transgenes by homologous recombination. Most importantly, chloroplast transgenic plants are eco-friendly because their transgenes are maternally inheritance in most crop plants. However, chloroplast transformation system has limited success in crops alike nuclear transformation. In the past two decades, great progress has been made to overcome the limitations of chloroplast transformation, thus expending chloroplast bioreactor to several important crops including soybean, carrot, lettuce, and oilseed. Therefore, it has become possible that chloroplast transformation of crops can be used not only for the improvement of agronomic traits, but also for the production of vaccines and high valuable therapeutic proteins in pharmaceutical industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2935-2941
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• 2010

This study used 3 kinds of experimental toothpaste with different contents(0%, 1.1%,2.2% of SLS. A total of 150 young adults in their 20's without any systemic disease were recruited for the study. These 150 subjects were subdivided into three groups(each having 50 subjects) according to the results of preliminary oral examination.After 4 weeks application of the three groups of toothpaste, Group C showed the highest halitosis index, followed by Groups A and B which had similar halitosis indices. Both oral sulfur compound and aerobic sulfur compound were measured at high content possibly because higher SLS content which is associated with the lower salivary flow rate is causing the xerostomia. SLS content was correlated with oral sulfur compound (r=0.412) and aerobic sulfur compound (r=0.285).