• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.199-204
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• 2015

Thermoplastic road markings are one of the most widely used road markings in the world. However, the durability of domestic road markings is relatively shorter than that of the global average of, approximately, three years. To overcome it, the conventional thermoplastic road markings were prepared by adding polyolefin and oxidized PE wax to conventional petroleum resin. In addition, the melting viscosity was designed below 500 cP at $220^{\circ}C$ as well as the optimum viscosity for spray painting, and embedding ratio of glass beads were controlled about 50~60% by spraying in an interval of 1 second. Also the glass bead adhesive ratio was improved by reducing the amount of $CaCO_3$ below 40 wt%. The retroreflectivity was tested under four different conditions to evaluate the abrasion resistance of thermoplastic road markings. The retroreflectivity coefficient satisfied the international standard ($150mcd{\cdot}m^{-2}{\cdot}lux^{-1}$) in this study, and TPRM-7 was determined as an optimal ratio.

• Toxicological Research
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• v.24 no.1
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• pp.87-91
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• 2008

The present study was conducted to monitor the level of triflumizole residues in fruits (apple and pear) and vegetable (cucumber) samples in order to assess risk posed by the presence of such residues to the consumer. Triflumizole was applied at a recommended dose rate to apple and pear pulps and to a cucumber sample. The samples were collected at harvesting time following several treatments (three and/or four treatments). Triflumizole was extracted with methanol and re-extracted into dichloromethane. The presence of triflumizole was determined by HPLC with UV detection at 238 nm following the cleanup of the extract by open preparative chromatographic column with Florisil. The versatility of this method was evidenced by its excellent linearity (> 0.999) in the concentration range between 0.2 and 4.0 mg/kg. The mean recoveries evaluated from the untreated samples spiked at two different fortification levels. 0.1 and 0.4 mg/kg, and ranged from 87.5${\pm}$0.0 to 93.3${\pm}$2.6 for the tested fruits and vegetable, respectively, and the repeatability (as relative standard deviation) from three repetitive determinations of recoveries were no larger than 6%. The calculated limit of detection was 0.02 mg/kg and the minimum detectable level of 4 ng for triflumizole was easily detected. When triflumizole was sprayed onto the apple trees three times at 50-40-30 and 40-30-21 days prior to harvesting and four times onto the pear trees at 40-30-21-14 days prior to harvesting, the mean residual amounts of 0.05 and 0.06 mg/kg for apples and pears, respectively, were not detected in all of the treatments. When the cucumber sample was fumigated four times at 7, 5, 3 and 1 day prior to harvesting, the mean residual amount was not detectable. Triflumizole can be used safely when sprayed (wettable powder, 30% active ingredient) and fumigated (10%) 4 times at 14 and 1 day prior to harvesting to protect the fruits and vegetable, respectively.

• Journal of Nutrition and Health
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• v.34 no.1
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• pp.30-38
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• 2001

This research was conduced to 1) examine the influence of milk group intake on the dietary, considering dietary diversity and nutrient adequacy, 2) identify which foods truly contribute to the intake of specific nutrients 3) point out the dietary problems of this age group. The subjects were 664(male 357, female 307) healthy toddlers of the ages of 12-36 months, who had neither been taking any medicine-type supplements nor had any diseases that affect the dietary intakes, chosen among the outpatients of university and private hospitals in Seoul and Kyonggi province during Mach-August, 1999. The 24 hour recall method and CAN Pro(food analysis program) were used to analyze the amount of nutrient intake. The grouping of the subjects for the analysis by monthly age was based on the 98 Korean Child growth standard. The results that the milk group intake showed significant negative correlations with the grain group(r=-0.194, p<0.01), the vegetable group(r=-0.115, p<0.01) and the fruit group(r=-0.125, p<0.01). It also showed that the more the milk group intake, the lower the Dietary Diversity Score(r=-0.131, p<0.01), and the more the intake of raw milk, the more dificient the intake of iron(r=-0.211, p<0.01), vitamin A(r=-0.169,p<0.01), vitamin B$_1$(r=-0.078, p<0.05) and vitamin C(r=-0.187, p<0.01). Foods contributory to nutrient intake for of 12-14 months of were mostly infant formula, and the contribution ratio was high. In the age of 15-17 months, the subjects obtained most of the nutrients from raw milk., liquid-type yoghurt, soybean milk, cooked rice, etc. As for iron intake, the age of 21-23 month obtained the most from ionic drinks, and 24-29 months from raw milk, chocolate cakes, ionic drinks, etc. Though the NAR(Nutrient Adequacy Ratio) and MAR(Mean Adequacy Ratio) generally tended to increase accordingly with the DDs, as for nutrients Ca, vitamin A, vitamin B$_1$, and vitamin C the NAR marked the highest when the DDS marked the lowest(due to infant formula). And for iron, even when the DDS was 5 the NAR value was low. Im conclusion, the more the milk group intake, the lower was the dietary diversity. High dependency on infant formula and others from milk group over the age of 12 months proved to result in a decrease of nutritious solid food intake, iron deficiency and a low dietary diversity score, which can lead to an unbalanced diet. Therefore, nutrition education towards mothers/caretakers of toddler is of urgent need, in order to reduce the fluid milk group intake of low nutritional density and to provide various solid foods the children. (Korean J Nutrition 34(1):30-38, 2001)

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.747-754
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• 2011

Purpose: The Abbe flap procedure has been used to correct disharmony of the upper and lower lips as well as for making a philtrum for patients with secondary cleft lip deformities. But the Abbe flap procedure adds two scars in addition to the prior operative scar on the upper lip. This study was conducted to determine the treatment outcomes of esthetic subunit excision of the scar on the philtrum and Abbe flap coverage for correction of cleft lip deformities with photogrammetric analysis. Methods: This study investigated a total of 11 patients with cleft lip deformities who underwent scar excision with Abbe flap coverage, and the patients were followed up for at least 6 months. Under general anesthesia, a mushroom-shaped Abbe flap was drawn on the lower lip with a width of 8 mm and a height 1~2 mm longer than that of the philtral midline. The epidermis and dermis of the scar on the upper lip were excised. In the cases with alar base depression, the orbicularis oris muscle was split vertically and transposed to the alar base. The Abbe flap was harvested as a pedicled flap containing a small amount of muscle and this was rotated 180-degree to be inserted into the upper lip. Mucosa, muscle, subcutaneous tissue and skin were closed in layers. The flap was divided at the 7~14 postoperative day. The postoperative outcomes were evaluated by using photogrammetric analysis. Three indices were measured from the standard clinical photographs taken before and after the surgery. For anthroposcopic assessment, observers described the postoperative outcomes using an ordinary scale method. Results: The postoperative values obtained in the photogrammetric analysis showed improvement as compared with the preoperative ones. Improved anthroposcopic outcomes were also noted. Conclusion: Scar excision and Abbe flap coverage were proven to be effective in improving protrusion and the height of the upper lip, the scar of the upper lip and the symmetry of Cupid's bow and the philtral column, as well as formation of the philtral dimple.

• Tunnel and Underground Space
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• v.20 no.3
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• pp.153-168
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• 2010

A fifth equation is required to determine the five independent elastic constants of a transversely isotropic rock from compression test of a single specimen. As an approximation proposed by Saint-Venant has been used for long time, it may cause an erroneous result in some cases, especially for specimen with low angle of anisotropy. Three equations were suggested replacing this traditional equation and proved to be applicable by the model analysis in the previous studies. As Saint-Venant's approximation is turned out the same as the first one of them, it has the characteristics that the apparent Young's modulus is monotonously increasing according to the anisotropic angle. The methodology to analyze the elastic constants from four independent strain measurements by uniaxial compressive test of a single standard specimen is concisely described, and the necessity and compatibility of new suggested equations are discussed. Saint-Venant's approximation can determine the elastic constants close to true values and other equations may be unnecessary in specimens with medium to large angle. Nevertheless, they may become applicable because they can produce the almost same amount. For the specimens of small angle of anisotropy, Saint-Venant's approximation may result in out of general ranges or thermodynamic constraints, but other suggested equations can produce the almost true value. Thus they can be applied before other alternative equation is known. The guide map constructed by model study may decide the most compatible one of the three equations.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.145-149
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• 2003

Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.483-496
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• 2018

NCS (National Competency Standards) has emerged as an issue of great importance amongst Korean universities and corporations. Although previously used mostly for vocational education purposes at colleges, NCS is currently receiving an increasing amount of attention from 4-year universities as well. In the ever-evolving information economy, the basic workplace skills defined by NCS, which include soft skills such as communication skills, problem-solving skills, and interpersonal skills, have now become more important than specific technical skills. This study analyzes the correlation between the basic workplace skills of NCS with participation in Formula SAE activities, a common component of Capstone design courses across North America and Europe. Data are derived from site visits to Formula SAE competitions, competition-related documents drafted by student participants, and questionnaires administered to student participants at the Formula SAE Lincoln completion and at the Korea KSAE competition. From the study findings, we claim that the basic workplace skills of NCS are closely correlated to participation in Formula SAE activities. Through a survey designed to measure the degree to which Formula SAE activities can enhance an individual's NCS Basic Workplace Skills, we find that these activities overall improved NCS basic workplace skills averaging 4.0 points above in the Likert 5-point scale. For reference the mathematical skills, communication skills, and problem-solving skills displayed statistically significantly correlation with NCS but the remaining 7 skills did not show a statistically strong correlation with NCS comparatively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.261-267
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• 2017

The interest in biodiesel is increasing rapidly. As a result, the price of vegetable oil that is used as a raw material for biodiesel is skyrocketing. Studies of biodiesel using animal waste as a means of solving these problems are underway. Biodiesel produced from animal fat contains considerably more saturated fatty acids than that produced from vegetable oil. In addition, it has a high cetane number and a high heating value. On the other hand, the fluidity decreases at lower temperatures because of the large amount of saturated fatty acids. For the biodiesel production, waste chicken oil and soybean oil were first purified. The raw materials were mixed at various ratios from 1:9 to 9:1. The methanol / oil molar ratio was also changed from 7 mol to 15 mol. The entire reaction time was one hour. The results showed that the optimal mixing ratio of soybean oil to waste chicken oil was 3:7, and the optimal methanol / oil molar ratio was 13. Moreover, the BD yield was 90.2%, the FAME content was 96.6%, and the LAME content was 4.1%. This result satisfied the Korea Industrial Standard (KSM2413).

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.255-261
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• 2014

The generation amount of radioactive waste has been rapidly increased by increase of the usage of radioisotope source in medical field. Especially, the use of the radioactive source of I-131 with short half-life of 8.02 days used in treatment of thyroid has been increased, and all of the wastes concerned have been disposed by means of the self-disposal method. 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, various radioactive wastes in medical fields are collected and measured for establishing the disposal methods and procedures of radioactive wastes. In addition, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and analytical half-life is considered. With comparing the theoretical half-life and the effective half life(7.72 days) which was based on the decay equation of measured data, it is resulted in the theoretical half-life is longer than effective half-life. The storage period of radioactive waste for self-disposal may be curtailed. The result of this study will be proposed as ISO standard.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.772-779
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• 2012

For improving performance of conical air diffuser generating fine bubble, both experimental and numerical simulation method were used. After adapting diffusers inner real scale bubble column, suitable for various diffuser submergence, the effect of diffuser submergence on oxygen transfer performance such as Oxygen Transfer Coefficient ($K_{L}a_{20}$) and Standard Oxygen Transfer Efficiency (SOTE) was investigated empirically. As flow patterns for various diffuser number and submergence were revealed throughout hydrodynamic simulation for 2-phase fluid flow of air-water, the cause of the change for oxygen transfer performance was cleared up. As results of experimental performance, $K_{L}a_{20}$ was increased slightly by 7% and SOTE was increased drastically by 39~72%, 5.6% per meter. As results of numerical analysis, air volume fraction, air and water velocity in bioreactor were increased with analogous flow tendency by increasing diffuser number. As diffuser submergence increased, air volume fraction, air and water velocity were decreased slightly. Because circulative co-flow is determinant factor for bubble diffusion and rising velocity, excessive circulation intensity can result to worsen oxygen transfer by shortening bubble retention time and amount.