• 전자공학회논문지 IE
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• v.43 no.4
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• pp.83-92
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• 2006

EMC(epoxy moulding compound) when operate with residual quantity processing after fixed quantity moulding inverse close way of designing by mechanical action inhalation so that may occur, solved of needle tip residual quantity and cause of thread extend phenomenon. In this paper, design to connect directly gun, washer tank and measuring beforehand amount that washing is easy and want minuteness fixed quantity that essential equipment in semi-conductor packaging process because develop EMC so that can molding with high speed consider.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.3-5
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• 2023

Objective: This study introduces exposure concentrations of time-weighted average standard (TWA) evaluation and short-time exposure standard (STEL) evaluation for trichloroethylene in the cleaning process. Methods: Trichloroethylene measurement was conducted according to the KOSHA Guide (A-24-2019) method. It was carried out twice. Results: As a result of the first measurement, TWA concentration exceeded 4 times the exposure standard and STEL concentration exceeded 16 times, but the inaccuracy and breakthrough of the collection time could not be considered, so the second measurement was conducted. The second measurement result was lower than the first measurement result, but exceeded the exposure standards (TWA, STEL). Conclusions: We were able to confirm that the exposure level of workers in the cleaning process using trichloroethylene exceeded the exposure standard. And it is also considered necessary to grasp the approximate concentration using a detector tube in the preliminary survey.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.189-201
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• 2016

A processing factor (PF) has been used to define the maximum residue limits of pesticide in a variety of processed fruit products. This study summarizes PF by the stage of fruit processing based on JMPR reports from 2010 to 2014. When we compared PF of 19 pesticides in apple products during the processing of washing, drying, canning, juice, sauce, puree and pomace, PF was higher than 1 only in pomace. In the comparison of 21 pesticides during the process of grape (washing, juice, wine and raisin), PF was higher than 1 in raisin. In the comparison of 19 pesticides during the process of orange (juice, oil and marmalade), PF was higher than 1 in oil. When 27 pesticides were compared during the process of tomato (juice, puree and paste), paste showed the highest PF value except pomace. During the process of plum (washing, drying and puree) with 12 pesticides, PF was higher than 1 in drying. The correlation coefficients between physical characteristics of pesticide (fat-solubility and volatility) and PF were statistically significant in the processes of apple juice, orange juice, tomato puree and paste and strawberry jam.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.116-122
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• 2011

This study was conducted to investigate the microbiological hazard of spoons and their cases carried by nursery school children and to evaluate the reduction effects of washing methods and ultraviolet (UV) treatments against Escherichia coli on the spoon and spoon case. A total of 78 spoons and their cases were sampled to test about total aerobic bacteria, coliform bacteria, Staphylococcus aureus, Bacillus cereus and Salmonella spp. Total aerobic bacteria were detected over 2.7 log CFU/100 $cm^2$ in 20 out of 36 spoons (55.6%), 9 out of 20 zipper-type spoon cases (45.0%) and 13 out of 22 plastic-type spoon cases (59.1%). Coliform bacteria were also detected in 19 out of 36 spoons (52.8%), 14 out of 20 zipper-type spoon cases (70.0%) and 14 out of 22 plastic-type spoon cases (63.6%). The pathogens tested in this study were not found in all samples except for the zipper-type spoon cases which were contaminated with Staph. aureus (2 samples) and B. cereus (3 samples). The results indicated that the sanitary conditions of spoons and their cases should be improved promptly. To evaluate the reduction effects of washing methods and UV treatments against E. coli, the spoons and their cases were treated at different cleaning times with and without soap, and different UV exposure times, respectively. E. coli with initial cell number of 4 log CFU on the spoons and their cases was not detected when they were cleaned at running water for 30 sec after dish sponging with soap for 30 sec. In UV treatments, E. coli with the same level of washing method was not detected after UV exposure for 15 minute in the spoons and their cases. From the results, the washing and UV treatment should be used to control the microbial contamination of spoons and their cases for more than 1 and 15 minutes, respectively.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.275-281
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• 2008

Background: This research aims to provide basic data for dental hygienists to implement the infection control after understanding the level of their implementation of infection control in case they have been trained of infection control or not. Method: The respondents in this research are the dental hygienists who worked in the Incheon or Gyeonggi areas between June 16 and July 5, 2008 and who attended complementary training conducted by the Seoul Branch of Korean Dental Hygienists Association in April 2008. A total of 191 questionnaires were distributed to them, and the frequency of the collected data was analyzed using SPSS WIN 12.0. Moreover, cross-tabulation analysis (${\chi}^2$) whose significance level was 0.05, was applied to the data in order to verify the statistical significance of the survey method. Result: There was significant difference in their practice to wear gloves and/or a mask, use a disposable apron and the time to change the apron depending upon the respondents' workplace. There was significant difference in the time to change their apron depending upon the respondents' time of service. 91.6% had been trained in the infection control: of them, 70.7% trained at their school. It was found that 68.6% of the respondents who had been trained in the infection control would wash their hands before treating a patient. 50.3% of the respondents who had been trained in the prevention of contamination would wear their gloves as needed for a basic treatment. Conclusion: Considering the above results of this research, it is concluded that it is necessary to provide practicing dental hygienists with many opportunities for systematic and practical training so that they may faithfully follow the guidelines for the prevention of contamination and to encourage hospitals to have a greater store of relevant facilities, equipment and supplies.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.492-506
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• 2019

Heavy metal contaminants in the shooting range are mostly present in a warhead circle or a metal fragment present as a particle, these fine metal particles are weathered for a long period of time is very likely that the surface is present as an oxide or carbon oxide. In particular, lead which is a representative contaminant in the shooting range soil, is present as more fine particles because it increases the softness and is stretched well. Therefore, by physical washing experiment, we conducted a degree analysis, concentration of heavy metals by cubic diameter, composition analysis of metallic substances, and assessment of applicability of gravity, magnetism and floating selection. The experimental results FESEM analysis and the measurement results lead to the micro-balance was confirmed thatthe weight goes outless than the soil ofthe same size in a thinly sliced and side-shaped structure according to the dull characteristics it was confirmed that the high specific gravity applicability. In addition, the remediation efficiency evaluation results using a hydrocyclone applied to this showed a cumulative remediation efficiency of 71%,twice 80%, 3 times 91%. On the other hand, magnetic sifting showed a low efficiency of 17%,floating selection -35mesh (0.5mm)target soil showed a relatively high efficiency to 39% -10mesh (2mm) efficiency was only 16%. The target treatment diameter of soil washing should be 2mm to 0.075mm, which is applied to the actual equipment by adding an additional input classification, which would require management as additional installation costs and processes are constructed. As a result, it is found that the soilremediation of shooting range can be separately according to the size of the warhead. The size is larger than the gravel diameter to most 5.56mm, so it is possible to select a specific gravity using a high gravity. However, the contaminants present in the metal fragments were found to be processed by separating using a hydrocyclone of the soil washing according to the weight is less than the soil of the same particle size in a thinly fragmented structure.

• Journal of dental hygiene science
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• v.9 no.1
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• pp.35-41
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• 2009

In previously study, many researchers have showed the infection control level and the knowledge of dental hygienists about dental infection control. But, they not tried to research the reason why hygienists don't keep to the infection control regulation closely. Therefore, this study was intended to highlight the affect factor that the infection control regulation keep in all dental hospitals well. The respondents in this research were the dental hygienists who worked in Incheon or Gyeonggi areas between June 16 and July 5, 2008 and who attended a complementary training program conducted by the Seoul Branch of Korean Dental Hygienists Association in April 2008. A total of 191 questionnaires were distributed to them, and the collected data was analyzed using SPSS WIN 12.0. Cross-tabulation analysis($X^2$), which significance level was 0.05, was applied to the data in order to verify the statistical significance of the survey method. According to replied, the reason why they don't used gloves were an unconvinced (38.9%), don't use by dentist (29.6%) and much expensive (9.3%). The gloves supplied a hygienist were proper in most case, 94.8%, but short in hospital, 12.0%. In order to take a good infection control they needed to change the conscious of dentist (66.5%), and the will of dentist is most important to do good infection control (37.2%). Subsequently, the will of dentist is the most important factor in infection control area and must be changed their mind on the infection control.

• Applied Microscopy
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• v.38 no.4
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• pp.293-306
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• 2008

The essential factor of acute respiratory distress syndrome (ARDS), an acute lung injury accompanied commonly by sepsis syndrome is accumulation of neutrophils in lung tissue. The study attempted to confirm whether a lung injury would be decreased with the anti-inflammatory effect of germanium by the treated germanium prior to the development of ARDS and whether nitric oxide influence in suppressing a lung injury. Test groups were divided in the following structure for experiment; CON that has been administered with sodium chloride to airway, LPS administered with endotoxin for 5 hours in the same amount and 5 hours of endotoxin administered Ge+LPS following 1 hours of pre-treated germanium. The result of a test using experimental animals, infilteration of neutrophils (p<0.001) in bronchoalveolar lavage fluid (BALF) was significantly decreased, the structure of lung tissue was preserved relatively well, and much neutrophils with distinct positive were observed on tunel staining which showed increase of apoptotic neutrophils in the pre-treated germanium group compare to the endotoxin administrated group. In observation of ultrastructural changes of cell in BALF, phagocytic alveolar macrophage was increased in alveolar space, the nucleus of most engulfed neutrophils were condensed, and some apoptosis neutrophils appears to be DNA fragmentation and effacement of cellular organelles were found in intercellular matrix in the pre-treated germanium group. However, the nitric oxide showed increase in all the groups excluding CON, and the nitric oxide effect such as degranulation diminishing of mast cells and apoptosis increase of neutrophils in the pre-treated group only. The situation appears that there was change in internal environment of the experimental animal by the pre-treated germanium before the nitric oxide is produced and the anti-inflammatory effect activated the pre-processed germanium by nitric oxide which activated following the change. Therefore, the nitric oxide created from macrophage in accordance with the pre-treated germanium appears to influence in alleviating a lung injury. Accordingly, acute lung injury is alleviated by the anti-inflammatory effect of germanium such as inhibition of neutrophils migration, induction of neutrophil apoptosis and increase of phagocytic function of phagocyte, and the nitric oxide produced from activated macrophage by germanium would influence in suppressing a lung injury.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.547-555
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• 1999

The economical manufacturing process of fluorescent sediments (FS) which makes use of the understanding of coastal sediment path has been suggested with respect to the Lagrangian viewpoint. First, the fluorescent liquids were made by the mixing of the fluorescent materials, acetone, and xylene. Second, the sediments collected in Gamami beach were desalinized by the freshwater washing, dried indoors to protect the fine-sediment scattering, and classified by the sieve analysis. Finally, the FS which have seven different colors were manufactured by the mixing of fluorescent liquids and prepared sediments. The FS were used to figure out the major sediment supply routes of the intake channel in the YoungKwang nuclear power plant. From the field experiments, it was shown that the sediments were suspended and dispersed by the strong seasonal NW wind and the tide, and the sediments in suspension were flowing into the intake channel due to very strong suction speed. All the FS injected in stations were detected in the channel sampling points, thus we concluded that the sediments in suspension and dispersion were flowing into the intake channel from all directions in adjacent coastal zone.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.6
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• pp.87-94
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• 2019

This paper contains the process of investigating the cause of fuel filter contamination of P&WC's PT6A-67A engine. An outline of the fuel filter contamination and configuration of the fuel supply line are specified. The analytical methods were classified into fuel component analysis and solid sediment analysis(EDX, TGA, optical microscope). In summary, the sulfur was detected from fuel tank sealant as a major contamination component. As a follow-up, P&WC and the Agency for Defense Development will conduct engine fuel filter cycle checks and fuel tank cleaning for engine operation.