If radioactive plumes are released outside due to loss of containment building integrity during a nuclear power plant accident, these materials might travel with the wind, affecting both the surrounding environment and neighboring countries. In China, most nuclear power plants are located on the eastern coast. Consequently, a radioactive plume generated during an accident could negatively impact even the western part of the Korean Peninsula due to westerly winds. To detect such problems early, respond quickly, and protect residents, a system that can monitor aerial radiation under normal conditions is needed. Additionally, a detection system that can operate in real-time in an emergencies conditions is required. The current method for aerial radiation measurement takes environmental radiation data from a monitoring post 1.5 m above the ground and converts it to altitude. To measure actual aerial radiation, an expansive area is surveyed by aircraft. However, this approach is both time-consuming and expensive. Thus, to monitor radioactive plumes influenced by environmental factors like wind, we need a radiation detector that can gauge both radioactivity and directionality. In this study, we developed a radiation detector capable of assessing both the radioactivity and directionality of a radioactive plume and conducted its performance evaluation. We miniaturized the radiation detector using a CZT (Cadmium Zinc Telluride) sensor, enabling its mounting on unmanned aerial vehicles like drones. It is configured with multi-channels to measure directionality of a radioactive plumes. For performance evaluation, we positioned two-channel CZT sensors at 90 degrees and measured the energy spectrum for angle and distance using a disk-type radioactive isotope. Using this method, we compared and analyzed the directionality performance of the multi-channel radiation detector. We also confirmed its capability to discern specific radioactivity information and nuclide types in actual radioactive plumes. Our future research direction involves mounting the multi-channel radiation detector on a drone. We aim to gather actual aerial radiation data from sensors positioned in various directions.

Previous research has compared still images employing the actor’s perspective to those employing the observer’s perspective and found that the former increases service evaluations if the consumers are promotion-focused, whereas the latter increases service evaluations if the consumers are prevention-focused. The research compares three kinds of vlogs, i.e., vlogs employing the actor’s perspective, vlogs employing the observer’s perspective without the actor’s face, and vlogs employing the observer’s perspective with the actor’s face. The results show that the highest service evaluations are induced by the actor’s perspective in case of promotion-focused consumers, whereas they are induced by the observer’s perspective without the actor’s face in case of prevention-focused consumers.

The Wide-Angle Polarimetric Camera (PolCam) is installed on the Korea’s lunar orbiter, Danuri, which launched on August 5, 2022. The mission objectives of PolCam are to construct photometric maps at a wavelength of 336 nm and polarization maps at 461 and 748 nm, with a phase angle range of 0◦–135◦ and a spatial resolution of less than 100 m. PolCam is an imager using the push-broom method and has two cameras, Cam 1 and Cam 2, with a viewing angle of 45◦ to the right and left of the spacecraft’s direction of orbit. We conducted performance tests in a laboratory setting before installing PolCam’s flight model on the spacecraft. We analyzed the CCD’s dark current, flat-field frame, spot size, and light flux. The dark current was obtained during thermal / vacuum test with various temperatures and the flat-field frame data was also obtained with an integrating sphere and tungsten light bulb. We describe the calibration method and results in this study.

During the decommissioning of a nuclear power plant, the structures must be dismantled to a disposal size. Thermal cutting methods are used to reduce metal structures to a disposal size. When metal is cut using thermal cutting methods, aerosols of 1 μm or less are generated. To protect workers from aerosols in the work environment during cutting, it is necessary to understand the characteristics of the aerosols generated during the cutting process. In this study, changes in aerosol characteristics in the working environment were observed during metal thermal cutting. The cutting was done using the plasma arc cutting method. To simulate the aerosols generated during metal cutting in the decommissioning of a nuclear power plant, a non-radioactive stainless steel plate with a thickness of 20 mm was cut. The cutting condition was set to plasma current: 80 A cutting speed: 100 mm/min. The aerosols generated during cutting were measured using a highresolution aerosol measurement device called HR-ELPI+ (Dekati®). The HR-ELPI+ is an instrument that can measure the range of aerodynamic diameter from 0.006 μm to 10 μm divided into 500 channels. Using the HR-ELPI+, the number concentration of aerosols generated during the cutting process was measured in real-time. We measured the aerosols generated during cutting at regular intervals from the beginning of cutting. The analyzed aerosol concentration increased almost 10 times, from 5.22×106 [1/cm3] at the start of cutting to 6.03×107 [1/cm3] at the end. To investigate the characteristics of the distribution, we calculated the Count Median Aerodynamic Diameter (CMAD), which showed that the overall diameter of the aerosol increased from 0.0848 μm at the start of cutting to 0.1247 μm at the end of the cutting. The calculation results were compared with the concentration by diameter over time. During the cutting process, particles with a diameter of 0.06 μm or smaller were continuously measured. In comparison, particles with a diameter of 0.2 μm or larger were found to increase in concentration after a certain time following the start of cutting. In addition, when the aerosol was measured after the cutting process had ended, particles with a diameter of 0.06 μm or less, which were measured during cutting, were hardly detected. These results show that the nucleation-sized aerosols are generated during the cutting process, which can explain the measurement of small particles at the beginning of cutting. In addition, it can be speculated that the generated aerosols undergo a process of growth by contact with the atmosphere. This study presents the results of real-time aerosol analysis during the plasma arc cutting of stainless steel. This study shows the generation of nucleation-sized particles at the beginning of the cutting process and the subsequent increase in the aerosol particle size over time at the worksite. The analysis results can characterize the size of aerosol particles that workers may inhale during the dismantling of nuclear power plants.

Uranium inventory in Boeun aquifer is facing the artificial reservoir that intended for supplying water to nearby cities (40-70 m apart) where, toxic radionuclides might mobile and enter the reservoir. In order to understand U mobility in the system, groundwater and fracture filling materials (FFMs) were analyzed for microbial signatures, C, O, Fe, S and U-series isotopes. The δ18O-H2O and 14C signatures suggested groundwater was originated from upland recharges dominantly and not affected by mixing with the surface water. However, the 234U/238U activity ratios (ARs) and 230Th/234U ARs in FFMs ranged from 0.93 to 1.67 and from 0.22 to 1.97, respectively, indicating that U was mobile along the fractures. In shallow FFMs, the U accumulations (~157 mg/kg) were found with Fe enrichments (~226798 mg/kg) and anomalies of δ56Fe and δ57Fe, implied U mobility in shallow depths was associated with Fe-rich environment. Also, in the shallow depths, Fe-oxidizers, Gallionella was prevailing in groundwater while Acidovorax was abundant near U ore depth. The Fe-rich environment in shallow depths was formed by pyrite dissolution, demonstrated using δ34S-SO4 and δ18O-SO4 distribution. Conclusively, the Fe-rich aquifer was capable of immobilizing the dissolved U through biotic and abiotic processes, without significant discharge into the nearby reservoir.

When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.

Radioactively contaminated metal components from a nuclear power plant must be decontaminated to reduce the risk of radiation exposure to workers, which can be cleaned using a foam decontamination used to reduce the amount of wastewater significantly. Metal components with a fixed radioactive contamination can be effectively decontaminated using a foam consist of 0.5wt% nonionic surfactant, 0.5 M H2SO4, and 0.2 M Ce(SO4)2. However, strongly acidic wastewater is generated from the decontamination method, which contains a high concentration of the nonionic surfactant and ionic materials with radioactive nuclides. This wastewater must be treated as a stable form. In this study, an integrated process of precipitation and low pressure distillation was evaluated for the treatment of wastewater. It was confirmed that the surfactant and ionic materials were effectively removed from the wastewater through the integrated process.

Pantala flavescens is a dominant Odonata species in the rice fields in Korea. To determine the effects of different temperatures on its larval growth and emergence, field and laboratory experiments were conducted. Larval growth was also monitored in mono-cropping and double-cropping rice fields. The growth of larvae was monitored every week by measuring the head width. In the field experiment, no difference was found in larval growth and emergence between the control temperature and +1.9°C of the control temperature. The larval growth was greater at 23°C than at 20°C laboratory temperatures, and no emergence was recorded at either temperature after eight weeks of monitoring. There was a quadratic relationship between larval growth and temperature in an incubator at five temperature regimes of 15, 20, 25, 30, and 35°C. Midseason water drainage caused the extinction of the existing individuals and newly hatched larvae dominated after re-watering in the rice fields. Larval size was greater in double-cropping fields than in mono-cropping fields in late July but the tendency was reversed in early August. The results of this study suggest that temperature warming will directly promote the larval growth of P. flavescens and indirectly influence seasonal growth via changes in water management in rice fields.

Novel eco-friendly adsorbents were prepared through pyrolysis and acid activation of raw almond leaf (RAL) to form almond leaf biochar (ALB) and chemically activated almond leaf biochar (CAL), respectively. The prepared adsorbents were characterized using TGA, FTIR, SEM–EDX, BET and XRD techniques and their physicochemical properties investigated. RAL, ALB and CAL were utilized for adsorption of BPB dye from aqueous solution using batch technique under optimum conditions. The optimum dye adsorbed by RAL, ALB and CAL were 92.83, 93.21 and 94.89%, respectively at pH 3, dye initial conc. (100 mg/L), adsorbent dose (0.04 g/25 mL), 60 min contact time and 301 K adsorption temperature. Although, Langmuir maximum monolayer adsorption capacities were found to be 365.36, 535.62 and 730.46 mg/g for RAL, ALB and CAL, respectively, but isotherm conformed to Freundlich model. Kinetic study confirmed suitability of pseudo-second-order model with rate constant 9.33 × 10–4, 9.91 × 10–4 and 12.60 × 10−4 g mg−1 min−1 for RAL, ALB and CAL, respectively. Negative values of thermodynamic parameters (ΔG and ΔH) established sequestration process to be spontaneous and exothermic. RAL, ALB and CAL were discovered to be highly efficient adsorbents that could be used in place of expensive commercial adsorbents.

Naturally occurring left ventricular hyperplasia is a rare but lethal disease. There are very few reports of this cardiac disease in captive nonhuman primates. In a colony of Macaca mulatta (Rhesus monkey) at California National Primate Research Center, a large number of rhesus macaques were diagnosed by autopsy with naturally occurring left ventricular hypertrophy without obvious underlying diseases over a 22-year period. The confirmatory diagnosis of ventricular hypertrophy was based on findings of notable left ventricular concentric hypertrophy with reduced left ventricular lumen, which is very similar to human ventricular hypertrophy cases. This report discusses an 11-year-old Macaca fascicularis monkey (Cynomolgus monkey, crab-eating macaque), weighing 2.95 kg, that was presented for enrollment in a pharmacokinetic (PK) study. During the PK experiment, the monkey died following a sudden decrease in percutaneous oxygen saturation and heart rate. Gross and histological examinations of the heart were performed. On gross pathology, the left ventricular wall was thickened, and the chamber lumen was reduced. In histopathological examination using hematoxylin- eosin and Masson-trichrome stains, fibrosis and myocyte disarray were not observed, but an increased cell density, compared to the normal heart, was confirmed. The autopsy results confirmed left ventricular hyperplasia as the major cause of death.

We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet―host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We find that the lens system has a star with mass Mh = 0.55+0.36 -0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62 -2.87 MJup, at a distance of DL = 5.67+1.11 -1.52 kpc. The projected star{planet separation is aㅗ = 3.92+1.10 -1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens{source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.

The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R2) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

Motile aeromonad septicaemia (MAS) mostly caused by Aeromonas hydrophila is a disease of high economic impact in freshwater organism. This study examined the seroconversion and seroprotection of formalinised local isolates of Aeromonas hydrophila in the Clarias gariepinus administered via different routes. Highly virulent Aeromonas hydrophila was treated with 40v/v formalin for 24 h. Bacterin was suspended to 0.5 McFarland standard and utilized to immunize Clarias gariepinus of 400±20 g in three groups with 50 samples each via three routes of administration. Antibody measurement taken at regular intervals before and after vaccination revealed a significantly higher antibody values in all routes compared to the control and difference was noticed at all intervals. Relative percent survival was 71.43, 62.86 and 57.14 intraperitoneal, intramuscular and immersion routes, respectively. Correlation analysis established a strong and direct relationship in the antibody generation through route of administration and efficacy of vaccine. This local vaccine was able to confer a high degree of immunity on Clarias gariepinus and can therefore be used to vaccinate against MAS.

Acute myocardial infarction (AMI) is considered the major cause of mortality in the world. Tremendous animal studies are performed to develop novel therapeutics, and this study aimed to induce porcine myocardial infarction model by using polyethylene terephthalate (PET). Coronary guidewire was placed in left anterior descending artery (LAD). The balloon angioplasty catheter was inserted at the back of the PET. The balloon catheter was carefully pushed forward, until the balloon marker was located in mid-LAD. Coronary angiography was performed pre- and post-occlusion at 28 days by C-arm. Histologic analysis of heart tissue was performed 28 days after inducing AMI. Thirty three pigs were anesthetized and underwent percutaneous coronary catheterization. All pigs were successfully embolized in mid-LAD by PET. Fifteen pigs died due to ventricular fibrillation during post-anesthetic recovery time, and overall experiment mortality was 45.5%. In 2,3,5- triphenyl tetrazolium chloride staining, gross finding of the ischemic heart lesion showed firm and white area of infarction associated with the apex and left ventricular posterior wall. Infarct on H&E-stained sections demonstrated a region without myocytes and rich with cardiomyocyte with atypical nuclei. Successful induction of AMI by using PET may provide the pathophysiological information of ischemic heart disease and improvement of therapy development for AMI.

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) is a high cadence observation program monitoring nearby galaxies with high probabilities of hosting supernovae (SNe). IMSNG aims to constrain the SN explosion mechanism by inferring sizes of SN progenitor systems through the detection of the shock-heated emission that lasts less than a few days after the SN explosion. To catch the signal, IMSNG utilizes a network of 0.5-m to 1-m class telescopes around the world and monitors the images of 60 nearby galaxies at distances D < 50 Mpc to a cadence as short as a few hours. The target galaxies are bright in near-ultraviolet (NUV) with MNUV < - 18.4 AB mag and have high probabilities of hosting SNe (0.06 SN yr-1 per galaxy). With this strategy, we expect to detect the early light curves of 3.4 SNe per year to a depth of R  19:5 mag, enabling us to detect the shock-heated emission from a progenitor star with a radius as small as 0.1 R. The accumulated data will be also useful for studying faint features around the target galaxies and other science projects. So far, 18 SNe have occurred in our target fields (16 in IMSNG galaxies) over 5 years, confirming our SN rate estimate of 0.06 SN yr-1 per galaxy.