국내 대기오염물질 배출량 통계에 따르면 상당한 대기오염물질이 선박에 의해 발생하고 있다. 따라서 선박으로부터의 대기오 염물질 배출 제한과 항만지역 대기질 개선을 위해 다양한 정책들이 시행되고 있고, 국제적으로도 선박에 의한 해양오염 방지를 위해 국 제 협약 등이 이루어지고 있다. 하지만 실제 운항하는 선박에서 배출되는 대기오염물질 측정에 관한 연구와 실험은 거의 이루어지고 있 지 않아, 본 연구는 이동식배출가스측정장비(PEMS)를 사용하여 실제 운항하는 9,169톤급 선박에서 발생하는 대기오염물질 배출량 평가에 대한 방법과 가능성을 제시하였다. RPM과 부하에 따라 배출량의 차이가 있었으며, NOX 배출량은 497-2,060ppm, CO2는 1.55-6.9%, CO는 0.002-0.14% 수준이다. 엔진 제조사에서 제공하는 Shop Test에 명시된 배출량과 실제 측정된 배출량에 차이가 있음을 확인하였다. 대상선박 의 전 항해구간에서 발생하는 각 대기오염물질 최대 배출량이 PEMS 측정 구간에 포함되는 것을 확인하여, 총톤수 10,000톤급 이내 선박 에 PEMS 활용 가능성을 검증하였다.

CFD was used to study the change in the operation of the governor to check the effect of response delay due to residual air in the governor cylinder, which adjusts the pump RPM of the Turbine Driven Aux. Feed Water Pump(TD AFWP) in the Nuclear power plant. As a result of analysis, as the amount of internal air increased, the time delay also increased proportionally, and a time delay of up to 0.2 sec. occurred. As in the theory, it was confirmed that the cylinder operation delay occurred depending on the presence or absence of a compressive fluid such as air, but the time delay wat not enough to significantly affect the pump operation.

In this paper, numerical simulations were conducted to secure both flow distribution and uniform flow discharge through a wall mount type air sterilizer. In order to increase the reliability of the simulation results where there is no well-known validation case for air sterilizer, mesh sensitivity study was performed under the constraint that y+ set to one for k-w SST turbulent modeling for both the air sterilizer and the fan. The installation of various guides and structures was reviewed in the point of flow distribution and pressure drop inside the sterilizer, and the exhaust pressure conditions were predicted to secure uniform flow discharge at outlets. This study has been done based on the computational analysis during the development stage of the air sterilizer, and the results will be verified through physical testing after production of prototype.

This study compares and analyzes the drogue shape applied to aerial refueling with the U.S. Navy drog shape through basic analysis of the model based on the flying fish shape, a marine creature. Flying fish is a creature that is advantageous for non-powered downhill, and this shape is applied to the probe feeding method to minimize the burden on the pilot and the need for refueling technology, which are disadvantages of the probe method. To this end, the results through analysis of basic studies were confirmed, and the superiority and insufficiency of the flying fish shape model and the US Navy drogue model were compared. Therefore, as confirmed through analysis, the flying fish model had a 14.1% lower maximum air pressure and a 9.1% faster maximum speed. Based on this, it is hoped that the advantages and disadvantages of flying fish shape models will be confirmed through actual flight tests in the future.

The Nuclear Cycle Experiment Research Center is one of the facility of the Korea Atomic Energy Research Institute (KAERI). This facility is a laboratory-scale version of pyro-processing technology. Mixture depleted Uranium (DU) and depleted Uranium (DU) feed material are used in this facility for pyro-research. During summer, air conditioners that maintain temperature and humidity are always in operation to protect analysis equipments. 15 air conditioners are installed in this facility. The condensate which is generated in 15 air conditioners is collected in one place to analyze. Sampling was performed to check the level of contamination, U, pH and gamma radiation test were performed. This paper shows the degree of contamination of air conditioner condensate which is generated in the radiation management area.

The Army, Navy, and Air Force are currently making various efforts to apply defense IoT technology by reflecting the characteristics of each military. However, there are concerns that comprehensive collection, management, and analysis may be limited because each military has no overlapping system or guaranteed interoperability of data, and there are inefficient aspects in terms of using and investing a limited defense budget. In this study, evaluation items and priorities for pilot projects were selected by applying Delphi technique and AHP method to determine which projects are preferentially effective when commonly applied in terms of Army, Navy, and Air force. As a result of the analysis, the project basis and driving force, project feasibility, performance and ripple effect, redundancy and connection were identified in the order of IoT-based small detachment units and unmanned base construction, intelligent smart unit, smart ground ammunition depot, and smart training management system. According to the comprehensive results reflecting the weights of each evaluation item, the fact that small detachment units and unmanned base construction project are recognized as the first project to be applied to the Army, Navy, and Air Force is a valid approach to be effective while each military is burdened with personnel management because of the reduction of manpower. Through the research results, it is expected that the direction of application to the policy of the defense IoT project can be confirmed in terms of efficient use of limited budgets.

Fungi are organisms that must be monitored and controlled in order to preserve valuable paper records. They reduce the quality of paper records by degradation and/or discoloration. As an effort to understand fungal contamination in the National Archives of Korea, the concentration of fungi in the indoor air of the unsterilized record rooms has been reported. However, what species are present in the facilities is not much known. In the present study, we examined the fungi isolated from the National Archives of Korea and found among them that there are fungal species which are newly documented in Korea. They were identified based on morphological properties and nucleotide sequences analysis of the polymerase chain reaction-amplified the internal transcribed spacer region of rDNA, calmodulin gene, and beta-tubulin gene. We report Cladosporium parahalotolerans, Cladosporium subuliforme, Ochroconis mirabilis, Penicillium angulare, and Penicillium fundyense as new instances of fungal species in Korea. Among these five species, P. angulare is known to able to produce cellulase and O. mirabilis as an opportunistic pathogen of human and animals.

This study measured the suspended fungal concentration in indoor multiple facilities nationwide. The regions were selected as representative cities by region: Seoul, Gyeonggi (Incheon), Gangwon, Gwangju, Daejeon, and Busan. A total of 2028 regional comparisons, including department stores, schools, public toilets, libraries, and banks, subway, sports facilities and comparative analysis were conducted for each multi-use facility industry. Among the nationwide, Among the regions, the average concentration of floating mold in indoor multi-use facilities was the lowest in Busan at 394.67 CFU/m3, followed by Gyeonggi and Incheon 487.90 CFU/m3, Seoul 542.84 CFU/m3, Daejeon 809.30 CFU/m3, Gangwon 1,145.22 CFU/m3, Gwangju was 1,371.10 CFU/m3 in the order. Busan was the lowest, and Gangwon was the highest. The reason that Busan, which has a high average temperature and population density, shows a lower mold concentration than Gangwon, is that floating mold in the indoor air is not affected by the external atmospheric environment, population density, and number of facility users. Although it cannot be said that there is no influence of the atmospheric environment, it was found that the indoor environment has different characteristics from the outdoor environment. The importance of air quality management has been confirmed, and further, it is necessary to subdivide the management standards by region and multi-use facilities, and the management standards need to be converted to maintenance rather than recommendations.

Air curtains, blowing air streams across a doorway, were installed in trial trains on subway line 7 in 2021 and they have been operated with dust collectors to improve the air quality of subway trains. In this study, we investigated the effects of air curtains on the indoor air quality in the trial subway trains. The concentrations of PM2.5 and carbon dioxide in the four selected cabins were measured in the morning hours (e.g., 7:30–11:30 am including the morning rush hour). The measurements were conducted on February 26, March 31, April 30, and May 14, 2021 and air curtain (AC)s and dust collector (DC)s in the four cabins were operated differently on those measuring days. All devices were turned off in the control cabin and only ACs, only DCs, and both the ACs and DCs were turned on in the other three cabins, respectively. The 4-h-averaged PM2.5 concentrations in the cabins, where only ACs and only DCs are turned on, are lower than in the control cabin by 18% and 26%, respectively. In addition, the joint operation of ACs and DCs can decrease the PM2.5 concentration by up to 42%. The time series of PM2.5 concentrations, measured on April 30, illustrate again that ACs block the intrusion of outside particulate matters. The 4-h-averaged carbon dioxide concentrations in the four cabins do not show monotonic differences between the cabins because of the generation of carbon dioxides inside the cabins. When the weights of individual cars and thus the numbers of passengers are similar between the cabins, the carbon dioxide concentrations in the ACs-operated cabins are higher than in the control cabin. This indicates that ACs can block the outward emission of carbon dioxides and maybe other indoor air pollutants as well.

Effects of substrate bed interior environments on mushroom qualities were investigated in oyster mushroom cultivation facilities in which either Reversible Air-Circulation Fans (RACF) blowing air in two directions (upwards and downwards) or customary Convection Fans (CF) with air blowing only upwards were operated throughout the cultivation period. Two days before harvest, the deviation ranges of the bed interior temperature and relative humidity in the facility using RACF were in the ranges of 1.0-1.3oC and 7.8-9.0% in the first growing cycle, and within 0.7-1.1oC and 10.0-11.4% in the second cycle. In the facility using CF, the ranges of variation in the indoor environment parameters (5.8-6.4oC and 21.3-23.1% in the first growing cycle, and 3.4-5.7oC and 14.6-18.3% in the second growing cycle) were much enlarged compared to those associated with RACF. These results strongly indicate that RACF significantly enhances air uniformity. Some mushroom qualities differed between growing cycles. For instance RACF in the first cycle gave somewhat better qualities than CF, but some qualities, like pileus diameter and stipe length, were slightly lower than those described for CF in the second cycle when the cultivation substrate weakened. The observation that some qualities worsened under RACF conditions, despite better air uniformity during the growing cycle, revealed the possibility that downward wind may exert a non-negligible negative effect on mushroom growth. Therefore in the future, making wind measurements on the interior and exterior of substrate beds is necessary to obtain insights into their influences on mushroom qualities. The RACF operation manual needs to be edited to convey this necessity.

This study is a plan on the way to strengthen the survival ability by increasing the use time of air respirator by applying emergency breathing method in the situation where firefighter has to wait for RIT (Rapid Intervention Teams) because it is impossible to escape by himself or emergency escape during isolation during field activities. The research procedure first drew problems by conducting a survey on fire fighters under the Seoul Fire and Disaster Headquarters, and conducted an experiment to compare normal breathing and emergency breathing with 20 members of the Seoul 119 Special Rescue Team, and suggested emergency breathing method and training process modeling that can be applied to each field situation based on the data obtained. The experiment was conducted over 9 weeks, and it was divided into three categories: field activity situation, movement (emergency escape assumption) situation, and place (assume waiting for RIT). In the field activity situation experiment, it was confirmed that the application of skip breathing method was appropriate and the use time of air respirator increased about 1.6 ~ 1.9 times. In the moving situation or the in-situ situation, wheel breathing method was appropriate and the use time of air respirator increased about 1.6 ~ 2.4 times. However, when conducting intense activities in the field activity situation, it is recommended to use it limitedly because it is difficult to apply the emergency breathing method. If emergency breathing is not clearly learned in the body, it is difficult to use in the field, so I think systematic and continuous training is necessary. This study suggests that the application of emergency breathing method is effective enough to strengthen the survival ability of firefighters in the field.

In this study, the cooling performance change according to the arrangement of the fin-tube heat exchanger using a single tube and the cooling performance change according to the air flow rate were studied. The arrangement of basic heat exchanger was set to 4 columns and 4 rows, and the performance change was studied while changing the columns and rows. In addition, the performance change was investigated by changing the air flow rate of the basic heat exchanger.

The purpose of this study was to investigate the possibility of using air potato (Dioscorea bulbifera) powder to make sponge cakes. The sponge cake batter was made by adding 0, 10, 20, 30, and 40% of air potato powder, and the resultant anti-oxidative properties and quality characteristics were analyzed. The study showed that the height, batter yield, and loss rate of sponge cakes decreased as increasing amounts of air potato powder were added, but the weight, viscosity, moisture content, and specific gravity increased. An evaluation of the color showed that the L and b values were highest in the control group but the a value was highest in the 40% group. There was no significant difference between samples in terms of cohesiveness, although the study showed a significant increase in the hardness, chewiness, and gumminess as the quantity of air potato powder in the sponge cakes increased. The total polyphenol content and DPPH radical scavenging activity increased noticeably as more air potato powder was added to the sponge cakes. The results thus showed that the study groups with the addition of air potato powder showed higher antioxidant activity than the control group.

There is a need for the purification of indoor air owing to a high rate of pollution in today’s world. For this, cabin air filters (CAFs) are widely used, which requires the addition of certain adsorbents to increase the volatile organic compound (VOC) removal efficiency. However, this addition causes high-pressure resistance, which may hamper commercial applications by requiring more energy and negatively affecting fresh air delivery rate. Hence, in this study, a high-performance combined CAF (CCAF) with excellent dust and chemical filtration performance and low differential pressure was prepared using granular activated carbon (GAC)/activated carbon fiber (ACF) mixed medium. The GAC/ACF mixed medium had higher air permeability than the ACF medium of the same weight, and it exhibited similar ultrafine dust filtration performance to the ACF medium without an increase in differential pressure. In addition, the GAC/ACF mixed medium showed excellent gas removal performance without increasing differential pressure by combining the VOC removal characteristics of the GAC and ACF filter media. The improved VOC removal performance of the GAC/ACF mixed medium was due to the hybrid effect of the hierarchical pore structures of the GAC and the nearly uniform pore structures of the ACF, which resulted in a slow and increased gas adsorption by the GAC and rapid gas adsorption of the ACF.

To reduce the air pollution from maritime activities, which is proven to have severe impacts on the worldwide environment and human health, many international regulations have been established. Therefore, an effective political strategy and a complete inventory of emissions are needed to control atmospheric ship pollution and comply with these international standards. The purpose of this study is to calculate the amount of emission in three operating modes (cruising, maneuvering, and hoteling) for some main pollutants emitted from container ships and trucks operating in Daesan port in Korea based on bottom-up methodology. The results showed that the volume of air pollution of about 6,500 tons from container ships and 1,455 tons from container trucks were emitted in Daesan port area. Also, a total of 4 billion won (about 3.6 billion won from container ships, and about 400 million won from container trucks) was estimated.

For this study, we established a system for the CPU cooling performance evaluation and conducted performance tests on air-cooling and water-cooling to understand the effect of the CPU cooling method on performance. For the performance evaluation, the test chamber and water-cooling system were set up, the workload S/W was selected, and a case file was created. In the case of the air-cooling, the CPU temperature is sensitively affected by the outside air temperature, the direction of the board installation, and the influence of the airflow formed around it, and may cause a lot of fluctuations in the CPU temperature. When the water-cooling system was applied, the CPU temperature decreased from 75℃℃ to 37℃ compared to the air-cooled type under the test conditions of 28.5℃ and 3LPM cooling water supply temperature and flow rate. As the CPU clock speed increased due to the decrease in temperature, it was found that the job execution time was reduced by 15~23%. In the future, it is expected that using this performance evaluation environment established through this study will enable us to easily conduct test evaluations for various processors, cooling methods, and changes in operating conditions.

Equipment used for ships operating in the polar regions, such as icebreakers, should consider countermeasures against freezing. This study performed a structural design that prevents freezing and tolerates thermal stress and wind pressure of the air vent louver heating blades. As boundary conditions for performing the analysis, analysis was performed when the flow rates at the inlet end were 10m/s, 20m/s 30m/s, 40m/s, and 50m/s. As a result of the analysis, if the CNT heating element can maintain the heating performance of 200°C, the blade can maintain the room temperature state except for the end of about 40mm. There are pressure drop between the front and rear of the air vent louver. It can be seen that the allowable wind speed varies depending on the design criteria. As a results, it is required to select an optimal heating temperature to prevent condensation of a blade, optimize the generation of compressive stress by thermal expansion, and trade off the wind pressure and thermal stress according to wind speed.