• Journal of Radiation Protection and Research
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• v.46 no.3
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• pp.120-126
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• 2021

Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks. Materials and Methods: Two exposure levels were examined, a "typical" mobile exposure of 100 kVp/1.6 mAs and a "high" exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility. Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 µGy to 67.82 µGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings. Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.769-776
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• 2018

According IEC 60601-1 ed3.1 and IEC 60601-2-45 regulation, diagnostic X-ray equipment should be display to measured and calculated air kerma area product. On the clinical X ray equipment, air kerma area product dosimeter would like to have an evidence for dosimeter accuracy and energy dependency. This study was performed to indirect calibration and energy dependency test for attached type air kerma area product (KAP) dosimeter by RQR standards beam quality. On the RQR5 beam quality, attached KAP dosimeter error showed -7.5%, respectably. On the RQR9 beam quality, attached KAP dosimeter error showed -10.4%, respectably. All RQR beam quality, average absolute error was $8.30%{\pm}2.85%$, respectably. On this study, attached KAP dosimeter was satisfied to IEC 60580 and AAPM TG 190. This calibration method of KAP dosimeter will help to performance maintain for clinical KAP dosimeter.

• Particle and aerosol research
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• v.20 no.2
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• pp.69-77
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• 2024

In this study, the performance of air cleaners installed in subway stations was evaluated using field test method and chamber test method in accordance with the standard for air cleaner. Also, the air filter maintenance period was examined by the performance reduction of air cleaners with respect to the air filter usage period. From the field tests, the clean air delivery rate (CADR) of air cleaners with filter in use was about 85% on average compared to the ones with new filter. The main factor of CADR reduction was not the decrease of filter efficiency but the decrease of airflow rate. The chamber test results shows that the CADR of air cleaners decreased with the usage time, but the proper filter replacement can make the CADR keep about 95% of the certified CADR. The expected filter replacement cycle measured by the field test method was calculated to be approximately 3.35 months (100 days). However, the replacement cycle was a large difference between 1.2 and 6.6 months with the different stations. Therefore, the replacement cycle should be individually investigated for each station. The use of air cleaners must be effective in reducing fine dust in subway stations. For more effective air quality management in subway stations, additional researches is necessary to define the appropriate capacity of HVAC system and air cleaner, and related maintenance for each station.

• Food Science and Preservation
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• v.3 no.2
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• pp.137-143
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• 1996

In order to produce the high-quality of dried red pepper with respect to a color and a taste we developed a automatic drier equipped with combined several heat energies(ADCHE). and compared the quality of ADCHE-treated red pepper with that of the pepper treated with conventional dryings such as natural, hot-air, and far-infrared ray dryings. The results obtained were as follows : (1) The contents of capsanthin varied significantly with drying methods within the range of 1.7 to 6. 4mg/g dry weight. The capsanthin level of red pepper treated with far-infrared ray drying was higher than that of the pepper treated with ADCHE showed the highest at 51.46mg/g dry weight of three drying methods. (2) As a result of determination of color intensity of-red-pepper using-a colorimeter, the red color intensity of the peppers was affected by drying methods irrespective of drying temperature, and especially a value of red pepper treated with ADCHE was appeared to be 19. 1, indicated that this pepper have the most bright color intensity. (3) The contents of soluble browing subatances increased with a increase in drying temperature, but L* value of red pepper treated with ADCHE was appeared to be 0.187, indicated that this red pepper have the most clear red color (4) The changes of capsanthin level of red pepper according to drying methodes did not show significantly, but generally a decreasing rate of capsanthin levels were lower in that order ADCHE

• Food Science of Animal Resources
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• v.42 no.4
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• pp.593-608
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• 2022

The effect of hot-air dried Lentinula edodes pileus (DLE) on the quality and organoleptic properties of rolled-dumplings was evaluated. DLE was prepared by drying at 60℃ for 24 h and added (Non, 7%, and 9%) to rolled-dumplings. The proximate composition, pH, color (CIE L^*, a^*, b^*), and cooking yield were analyzed. Texture profile analysis, electronic-nose (e-nose), electronic-tongue (e-tongue), and organoleptic evaluation were also conducted. The cooking yield of dumplings with 9% DLE was significantly lower than that of the congeners without DLE, whereas 7% DLE did not lead to significant differences compared without DLE. With increasing DLE addition, the pH and lightness of the dumplings decreased significantly, whereas the redness tended to increase. The texture profile was significantly higher for the dumplings with DLE compared to those without DLE. E-nose analysis confirmed that DLE addition led to the positive odors (methanethiol: meaty, sulfurous; 3-methylbutanal: malty, toasted) and the negative odors (trimethylamine: ammoniacal; acetic acid: acidic, sour). E-tongue analysis showed that DLE addition decreased the intensity of the sourness and increased the intensity of the saltiness and umami of rolled-dumplings. DLE addition improved the overall organoleptic properties, but 9% DLE can be recognized as a foreign substance in organoleptic acceptance. Consequently, DLE has the potential to serve as a flavor and odor enhancer for rolled-dumplings, and the addition of DLE can positively improve consumer acceptance by improving the quality and organoleptic properties.

• Clean Technology
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• v.29 no.1
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• pp.22-30
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• 2023

Mongolia is experiencing some of the world's most serious air pollution problems. The air pollution is especially severe during the winter when raw coal and low-grade fuels are used to heat homes in Ger villages. The impact of this pollution has created significant health and socioeconomic challenges for the country. In order to mitigate this air pollution, this study analyzed the fuel quality of the low-grade fuels and Mongolian waste cooking oils used in Ulaanbaatar, Mongolia. Then the environmental characteristics of traditional stove combustion and a prototype combustion heating device were compared and analyzed. In addition, the effect of replacing the heating devices was evaluated by analyzing their risks to humans. Analysis of the fuel characteristics showed that briquettes had relatively low environmental properties as a result of their high ash, N and S content. Also, after analyzing the combustion characteristics, it was found that the air quality improvement effect was higher when waste cooking oil was burned compared to the three types of coal that were analyzed. Finally, this study evaluated the impact of replacing the Mongolia traditional stove with a prototype stove that uses waste cooking oil. The results of this study are expected to help to mitigate the air quality problems currently observed in Ulaanbaatar, Mongolia.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.597-603
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• 2014

In this study, the physicochemical and sensory quality characteristics due to the influence of various thawing methods on electro-magnetic and air blast frozen pork were examined. The packaged pork samples, which were frozen by air blast freezing at $-45^{\circ}C$ or electro-magnetic freezing at $-55^{\circ}C$, were thawed using 4 different methods: refrigeration ($4{\pm}1^{\circ}C$), room temperature (RT, $25^{\circ}C$), cold water ($15^{\circ}C$), and microwave (2450 MHz). Analyses were carried out to determine the drip and cooking loss, water holding capacity (WHC), moisture content and sensory evaluation. Frozen pork thawed in a microwave indicated relatively less thawing loss (0.63-1.24%) than the other thawing methods (0.68-1.38%). The cooking loss after electro-magnetic freezing indicated 37.4% by microwave thawing, compared with 32.9% by refrigeration, 36.5% by RT, and 37.2% by cold water in ham. The thawing of samples frozen by electro-magnetic freezing showed no significant differences between the methods used, while the moisture content was higher in belly thawed by microwave (62.0%) after electro-magnetic freezing than refrigeration (54.8%), RT (61.3%), and cold water (61.1%). The highest overall acceptability was shown for microwave thawing after electro-magnetic freezing but there were no significant differences compared to that of the other samples.

• Tunnel and Underground Space
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• v.26 no.4
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• pp.274-282
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• 2016

Natural ventilation is employed in limestone mines that have been currently operated in Korea, and there has been a growing issue of a significantly weak airflow caused by the large-scale excavation. Thus, the air quality in the working area is considerably poor. In order to improve this circumstance, it is mainly required to examine ventilation performance. In this study, the examination of ventilation efficiency was conducted by using tracer gas method. The result of this work indicated detailedly the ventilation problems in research mine, in that extremely low air velocity, recirculation, and air change rate were evaluated quantitatively using tracer gas. Therefore the ventilation performance evaluation using tracer gas can be opted as a precise method to improve the working area in mines.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1303-1308
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• 2011

In the modern society various types of transportation mode are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day. Because of interests on the indoor air quality (IAQ) of underground public facilities, concerns on IAQ of subway system by many people are increasing. There are several approach to improve IAQ of subway station, such as installing platform screen door (PSD), frequent tunnel washing-out, and etc, however there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin since the problem of maintenance cost. Therefore, the ultimate object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. The subway cabin air purifier (SCAP) was developed for removing particulate matters and gases pollutants inside a cabin. The whole system was designed and the roll-filter device was manufactured based on numerical prediction results. It is expected that SCAP could reduce indoor air pollutants in the subway cabin practically and it can be applied to other part of transportation vehicles.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.136-144
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• 2016

The air-conditioning industry is closely related to types of lifestyles, climate, and products. With the improvement of national income, the pursuit of pleasant living and working environments, and South Korea's four seasons and distinct climatic conditions, demand for air conditioning has increased. In addition, the industry is becoming increasingly precise and cooperative, and the increase in the domestic production of sophisticated air conditioning and continued growth of future industrial cooperation are expected to rapidly rise. Accordingly, the study of air piping systems can improve the productivity and quality of products and cost savings and can achieve vibration reduction. Additionally, using a heat treatment furnace for copper tube annealing treatment reduces the risk of using an oxy-acetylene torch.