Background: The oxygen uptake efficiency slope (OUES) is the most important index for accurately measuring cardiopulmonary function in patients with acute ischemic heart disease. However, the relationship between the OUES variables and important cardiopulmonary function parameters remain unelucidated for patients with acute ischemic heart disease, which accounts for the largest proportion of heart disease. Objects: The present cross sectional clinical study aimed to determine the multiple relationships among the cardiopulmonary function variables mentioned above in adults with acute ischemic heart disease. Methods: A convenience sample of 110 adult inpatients with ischemic heart disease (age: 57.4 ± 11.3 y; 95 males, 15 females) was enrolled at the hospital cardiac rehabilitation center. The correlation between the important cardiopulmonary function indicators including peak oxygen uptake (VO2 peak), minute ventilation (VE)/carbon dioxide production (VCO2) slope, heart rate recovery (HRR), and ejection fraction (EF) and OUES was confirmed. Results: This study showed that OUES was highly correlated with VO2 peak, VE/VCO2 slope, and HRR parameters. Conclusion: The OUES can be used as an accurate indicator for cardiopulmonary function. There are other factors that influence aerobic capacity besides EF, so there is no correlation with EF. Effective cardiopulmonary rehabilitation programs can be designed based on OUES during submaximal exercise in patients with acute ischemic heart disease.

Natural environmental resources are considered a prospective source of microorganisms capable of producing biocatalysts with great potential in industrial areas. Arable soil fertilized with peat moss is a habitat for various microorganisms. The present research focused on the isolation and identification of hydrolase-producing bacteria that thrive at a broad temperature range. In this study, a total of 33 strains were isolated from arable soil fertilized with peat moss (Silla Garden in Busan, South Korea). The isolated bacteria were mesophiles and thermophiles with a wide temperature range. Taxonomic identification showed that the isolated strains belonged to 2 phyla, 5 families, 10 genera, and 24 species. Subsequently, the isolated strains were screened for hydrolase (amylase, lipase, and protease) activity. All isolates possessed activity of at least one enzyme and six bacterial isolates produced combined extracellular enzymes. Diversity of soil bacteria species in the present study suggest the potential of soil bacteria in the various industrial applications.

At high temperatures, molten salt has heat transfer properties like water. Molten salt has the characteristics of a strong natural circulation tendency, large heat capacity, and low thermal conductivity. Unlike sodium, molten salt does not react explosively exothermically with air. However, molten salt has a strong tendency to corrode materials, and its properties are easily changed by a sensitive reaction to oxygen and moisture. Therefore, it is necessary to study material corrosion properties and chemical control methods for nuclear fuel salts, which are eutectic mixtures. In this study, the optimal operation method of the thermal convection loop is established to perform the experiments on the molten salt. The process describes briefly as follows. The operation step consists of preparation, purification, transportation, and operation. In the preparation, the step checks the entire structure and equipment (TC, blower, vacuum pump, etc.). And melt the salt mixture at a high temperature (670°C) slowly in the purification step. Before injecting the molten salt, the surface temperature of the entire loop must retain temperature (about 500°C) constantly. Completely melted molten salt in the melting pot is flow along the pipe of the thermal convection loop in the transportation step. Lastly, the convection of molten salt goes to keep by the temperature difference. The thermal convection loop can be utilized for various experiments such as corrosion tests, component analyses, chemistry control, etc.

Molten salt used in the multipurpose molten salt experiment must be of high purity. Depending on the purpose of the experiment, only the base component of the molten salt be used, or a component simulating a nuclear fission product be added to the base component and used. In all cases, an increase in the concentration of impurities such as oxygen and moisture may lead to an erroneous interpretation when analyzing the experimental results. Therefore, molten salt should be purified before use. In this study, the purification of molten salt is described for multi-purpose molten salt experiments. The salt mixture is selected as MgCl2-NaCl and is quantified at a mixing ratio of 43mol%:57mol%. The salt mixture is treated in a glove box environment because of must minimize the reaction of adsorbing oxygen and moisture when the salt mixture is exposed to the atmosphere. MgCl2 is more likely to contain water than NaCl, the purification of the NaCl-MgCl2 mixture is established according to the purification process for removing water from MgCl2. A process for purifying the salt mixture briefly consists as follows: drying moisture, melting salts, purification, removing HCl, and stabilization. Through the process be able to obtain high-purity molten salt and more accurate experiment results.

Once a radioactive material is released from the nuclear power plant (NPP) by accident, it is necessary to understand the behavior of radioactive plume to protect residents adequately. For this, it is essential to measure the radiation dose rate around NPPs at important locations. Our previous study developed a movable radiation detector that can be installed quickly in an accident to measure gamma dose rate in areas where environmental radiation monitoring system is not installed. The data measured by the detector are transmitted to the server in real-time through LoRA wireless communications. There are two methods to use LoRA communications; one is self-network, and the other is the network provided by the mobile carrier. A signal receiver, called a gateway, should be equipped near the installation location of radiation detectors to use a self-network without using the mobile carrier’s system. In other words, the movable radiation detectors we made can function if there should be any gateway near them. The distance capable of communication between gateway and detector is about 8 km in an open area without significant obstacles. Korea has many significant obstacles, such as mountains around most NPPs. Thus, the gateways could be installed in the proper position before the accident to operate the movable radiation detectors without problems. If the gateway is located at a high position like a mountain top, it could cover a wide area. In this study, the elevation database in the area around the NPPs was collected and analyzed to determine where gateways should be installed. The analysis range is limited in the urgent protective action planning zone. The optimization was also performed to minimize the number of gateways.

우리나라 정원의 식물 이용 현황을 알아보고자 전국 36개 정원을 대상으로 정원식물을 조사하였다. 정원은 6가지 유형 으로 구분하였다. 그 결과, 36개소 정원에는 정원식물 712종 류가 식재되고 있었다. 교목, 관목, 초본의 비중은 평균 1:2:7 이었다. 개별 정원(10×10㎡)에서 교목은 평균 2.5종으로 12.6%, 관목은 4.1종 20.7%, 초본은 13.2종 66.7%를 차지했다. 식재 빈도 상위 5%에 40여 종이 포함되었으며, 맥문동, 일본조팝나 무, 수국, 회양목, 단풍나무, 옥잠화, 에키네시아, 산철쭉이 대 표적이었다. 양지형 정원에는 관목이 상대적으로 적고 초본이 많았으며 다른 유형보다 20~40% 이상 다양했다. 그늘형은 초 본보다 교목이 많았으며, 건조형 및 습지형과 마찬가지로 식 재 다양성이 20% 감소했다. 옥상정원의 도시형 정원은 초본 이 전체의 80~90%를 차지하고, 해안형 정원에는 목본과 초본 이 1:1로 목본 중심의 식재 특성을 보였다. 결과적으로 정원 유형에 따라 식재 다양성과 구성 비율이 명확한 차이를 나타 냈다.

Despite having a low electrical conductivity, graphene oxide (GO) is used as an anode material in lithium-ion batteries (LIBs) owing its good processability in large quantities. GO is reduced by chemical or thermal treatments to enhance its electrical conductivity. In this study, high-performance GO anodes with polydopamine (PDA) and polyethylenimine (PEI) as binders were fabricated. Gamma (γ)-ray irradiation was applied to the GO–PDA–PEI hybrid sheets to covalently cross-link the GO sheets and binders with an amide bond. The covalent crosslinking was confirmed by Fourier-transform infrared spectroscopy analysis. Further, X-ray photoelectron spectroscopy results showed that γ-ray irradiation produced a reduced GO sheet, which resulted in an increase in the electrical conductivity by 30%. By characterizing the electrochemical properties, we found that the γ-ray irradiation facilitates the stability and increases the charge/discharge capacity by crosslinking GO and PDA–PEI binders and reducing the GO sheets.