Background: Sperm quality and the number of sperm introduced into the uterus during artificial insemination (AI) are pivotal factors influencing pregnancy outcomes. However, there have been no reports on the relationship between sperm concentration at AI and sperm quality in Hanwoo cattle. In this study, we examined sperm quality and pregnancy rates after AI using sperm inseminated at different concentrations. Methods: We evaluated the motility, viability, and acrosomal membrane integrity of sperm at different concentrations (10, 15, 18, and 20 million sperm/straw) in 0.5-mL straws. Subsequently, we compared the pregnancy rates after AI with different sperm concentrations. Results: After freeze-thawing, sperm at the assessed concentrations showed similar viability and acrosomal membrane integrity. After AI, cattle in the 10 million group had significantly lower pregnancy rates compared to those in the 18 and 20 million groups. Conversely, there were no statistically significant variances observed between cattle in the 10 and 15 million groups. Conclusions: Sperm at concentrations of 10, 15, 18 and 20 million per straw exhibited comparable motility, viability, and acrosomal membrane integrity. However, a concentration of at least 18 million sperm per straw is required to achieve a consistent rate of pregnancy rate in Hanwoo cattle after AI.

가는잎향유[Elsholtzia angustifolia (Loes.) Kitag.]는 화형 이 아름답고, 정유 특유의 향기가 좋아서 분화용 및 지피용 관 상식물로 수요가 증가하고 있고, 전초에는 약효가 있다고 알 려져 있다. 본 연구는 가는잎향유의 육묘에 미치는 플러그 트 레이 셀 사이즈, 파종립수, 차광정도, 추비농도 등의 영향을 구명하기 위하여 수행되었다. 연구결과, 플러그 트레이 셀 사 이즈는 용량이 증가할수록 유묘의 초장, 엽수, 마디수, 근장, 지상부 생체중이 유의적으로 증가하였다. 파종 립수는 2립 파 종 시 가장 효율적이었고, 파종량이 증가할수록 생육이 감소 하였다. 차광정도가 높아질수록 초장은 증가하였고, 경직경, 엽수, 마디수는 55% 차광에서 가장 우수하였다. 추비 처리 시 공시비료 1000배 처리구에서 생육이 가장 양호하였다. 따라 서 가는잎향유의 육묘 시 162셀 트레이에 원예상토를 채운 다음 셀 당 2립 파종한 후 55% 차광막이 설치된 육묘상에서 공시비료 1000배로 엽면시비하는 것이 가장 효과적인 것으로 생각된다.

This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.

정보통신기술(Information and Communication Technology)과 기존 교통수단의 융복합으로 수소자동차, 자율주행자동차 등과 같은 새로운 교통수단 등장으로 광역 이동과 같은 이동성이 향상될 것으로 기대되고 있다. 또한, 보다 빠른 광역 이동성 확보를 위해 BRT 전용차로 도입에 대한 논의가 계속되고 있으므로 본 연구는 BRT 전용차로 구간에서 자율주행자동차의 혼입률 및 대중교통 전환율에 따른 시나리오를 설정해 서비스수준 분석을 기반으로 잉여차로 발생 가능성을 확인하였다. 더불어, 미래교통량 증가와 자율주행 기술 의 발전이 BRT 전용차로 운영 구간에 미치는 변화를 분석해 도로의 자산가치 산정을 목적으로 하고 있다. 설정한 시나리오에서 도로 가 기능을 발휘할 수 있는 일정한 서비스수준(Level of Service, LOS)를 유지하는 자율주행자동차 혼입률 수준을 파악하였으며, A~F 의 6단계로 구분하여 결과를 도출하였다. 도로의 자산가치 산정방법은 국가회계기준에서 제시하고 있는 토지의 대체적 평가방법 4가 지 방법과 보다 객관성을 확보한 새로운 자산가치 평가방법을 준용하여 도로의 자산가치를 산정하였다. 분석 결과, 간선도로 서비스수 준을 통해 BRT 전용차로를 시행하면서 연속류 구간에서는 자율주행자동차 혼입률이 75%되는 경우 편도 3차로에서 편도 2차로로 1차 로 감소가 이루어져도 현재의 서비스수준을 유지할 수 있으며, 단속류에서는 자율주행자동차의 혼입률이 50%되는 시점에 편도 4차로 에서 편도3차로 1차로 감소 시 동일한 효과를 발휘할 수 있음을 확인하였다. 즉, 연속류 구간에서 자율주행자동차 비율이 75% 및 단 속류 구간에서는 자율주행자동차의 비율이 50%되는 시점에서 1차로에 대한 도로 자산가치가 발생할 수 있음을 알 수 있었다. 이와 같은 잉여차로는 보행약자를 위한 보행 공간 및 자전거도로, 개인형이동장치((Personal Mobility, PM)전용도로, 완충녹지 등의 완전도 로로 활용될 수 있음을 시사하고 있다.

본 연구는 식물공장에서 아쿠아포닉스와 수경재배에서 재배된 딸기의 무기양분 흡수율, 생육, 수량을 비 교하고자 수행되었다. 양어는 비단잉어(Cyprinus carpio) 12마리를 수조(W 0.7m × L 1.5m × H 0.45m, 472.5L)에 367.5L 물을 채운 후 입식하였고 5.44kg·m-3 밀도로 사육하였다. 딸기 모종 30개체는 펄라이트를 채운 포트에 정식 하여 아쿠아포닉스 시스템 베드(W 0.7m × L 1.5m × H 0.22m)에 장착하였고, 모종 30개체는 네트포트에 정식한 후 담액수경(DFT)시스템 베드(W 0.7m × L 1.5m × H 0.22m)의 아크릴판(140 cm × 60 cm, Ø80 mm)에 장착하였다. 재 배기간 동안 아쿠아포닉스 수조액의 pH와 EC는 각각 4.3－6.9, 0.32－1.14dS·m-1 수준이었고, 수경재배는 각각 5.1 －7.5, 1.0－1.8dS·m-1이었다. 아쿠아포닉스 수조액의 NO3-N와 NH4-N 농도는 수경재배보다 각각 약 3.6, 2.2 me·L-1 높았다. P, Ca, Mg, S 농도는 수경재배보다 각각 약 0.76, 3.1, 0.8, 0.9me·L-1 높았으며, K와 Fe는 각각 약 0.8me·L-1, 0.5mg·L-1 낮았다. 딸기 잎의 무기이온 함량은 두 재배 처리 간 유의차가 없었으며 엽내 K 함량은 적정 범위를 보였 다. 정식 후 58과 98일 사이에 아쿠아포닉스에서 재배된 딸기의 T-N와 P 흡수율은 수경재배보다 각각 1.5, 1.9배 높 았고 K 흡수율은 유의차가 없었다. 개체당 과실수는 아쿠아포닉스에서 수경재배보다 유의하게 많았으며, 상품과 생체중, 건물중, 과실의 과장과 과폭은 수경재배에서 아쿠아포닉스보다 높았다. 결과를 종합하면, 아쿠아포닉스에 서는 수조액의 물고기 배설물과 먹이 잔여물에 의한 고체 입자의 비료성분을 지속적으로 가용하여 활용한다는 것 을 알 수 있다.

Despite its profound impact on athletic performance, the significance of heart rate recovery (HRR) has been insufficiently addressed in the filed of sports science, particularly in the context of weightlifting characterized by brief and intense exertions involving heavy weights. Serving as a valuable indicator of autonomic nervous system and cardiovascular function, HRR assumes a pivotal role in weightlifting. This comprehensive review aims to delineate the specific demands for HRR in weightlifting, shedding light on the often overlooked cardiovascular considerations within training regimes focused on strength and power. The investigation scrutinizes the repercussions of HRR on weightlifting performance, seeking to elucidate how inadequate recovery intervals may result in physiological and psychological consequences. These consequences encompass a distorted perception of effort, disruption of coordination, compromised posture due to irregular breathing, and an overall decline in lifting capacity. The review systematically presents compelling evidence pertaining to heart rate response and recovery patterns during weightlifting, underscoring the critical importance of well-structured rest periods. Furthermore, the review delves into a comprehensive discussion of factors influencing HRR in weightlifting, encompassing variables such as sex, age, cardiovascular function, hydration, nutrition, and psychological aspects. Finally, a key emphasis is placed on the integration of effective HRR techniques into the training regimens of weightlifters, thereby ensuring sustained and optimized performance outcomes.

Currently, Japan is undertaking a nationwide project to measure and map radioactive contamination around Fukushima, as part of the efforts to restore normalcy following the nuclear accident. The Japan Atomic Energy Agency (JAEA) manages the Fukushima Environmental Safety Center, located approximately 20 km north of the Fukushima Daiichi nuclear power plant in Minamisōma City, Fukushima Prefecture. In collaboration with the JAEA, this study involved conducting comparison experiments and analyses with radiation detectors in high radiation environments, a challenging task in Korean environments. Environmental radiation surveys were conducted using three types of detectors: CZT, NaI(Tl), and LaBr3(Ce), across two contaminated areas. Dose rate values were converted using dose rate conversion factors for each detector type, and dose rate maps were subsequently created and compared. The detectors yielded similar results, demonstrating their feasibility and reliability in high radiation environments. The findings of this study are expected to be a crucial reference for enhancing the verification and supplementation of procedures and methods in future radiation measurements and mobile surveys in high-radiation environments, using these three types of radiation instruments.

Air blower has been widely used in many industrial fields such as wind tunnel and large ventilation systems. Its performance is affected by operating conditions and system geometry of inpeller and duct, and these design parameter optimization is essential for the effective development. CFD analysis is carried out to investigate the air flow field characteristics with outlet total pressure in a blower system. Intake air into the impeller blade through the inlet is compressed, and then gradually discharged from the outlet with ascending total pressure, and predicted results are compared with test data. Especially this overall pressure difference in the blower system severely depends on the flow rate. These results are expected to be used as applicable design data for blower performance improvement.

Biocide dichlofluanid breaks down quickly and accumulates easily in sediment, potentially causing a persistent impact on various marine organisms. We analyzed the potential toxicity of dichlofluanid on major aquaculture species in Korea, Undaria pinnatifida. Female gametophytes of U. pinnatifida were exposed to dichlofluanid at concentrations of 0, 1, 2, 4, 8, 16, and 32 mg L-1, and their survival and relative growth rate were analyzed. The no observed effect concentration (NOEC), lowest observed effect concentration (LOEC), and median lethal concentration (LC50) for female gametophyte survival were determined as 1, 2, and 10.82 (95% CI: 8.87-13.23) mg L-1, respectively. The NOEC, LOEC, and median effective concentration (EC50) for relative growth rate were 1, 2, and 6.58 (95% CI: 6.03-7.17) mg L-1, respectively. Female gametophytes of U. pinnatifida were expected to experience toxic effects at concentrations above 2 mg L-1 of dichlofluanid. These research findings are expected to serve as important reference data for evaluating the toxicity effects of U. pinnatifida in its early life stages when exposed to dichlofluanid.

PURPOSES : This study is to initiated to estimate the impact of mixed traffic flow on expressway section according to the market penetration rate(MPR) of automated vehicles(AVs) using a enhanced intelligent driver model(EIDM). METHODS : To this end, microscopic traffic simulation and EIDM were used to implement mixed traffic flow on basic expressway section and simulation network was calibrated to understand the change of impact in mixed traffic flow due to the MPR of AVs. Additionally, MOEs of mobility aspects such as average speed and travel time were extracted and analyzed. RESULTS : The result of the impact of mobility MOEs by MPR and level of service indicated that 100% MPR of AVs normally affect positive impact on expressway at all level of service. However, it was analyzed that improvements in the level of service from LOS A to C are minimal until the MPR of AVs reaches 75% or higher. CONCLUSIONS : This research shows that impact of MPR of AVs using EIDM of mixed traffic flow on basic expressway. Increasing MPR of AVs affects positive impact on expressway at all level of services. However, MPR from 25% to 75% of AVs in LOS A to C shows minimal impacts. Therefore, to maximize the effectiveness of AVs, appropriate traffic operation and management strategies are necessary.

Purpose: Even today, cancer remains a challenge to overcome. The purpose of this study is to understand the current status of lip-oral-pharyngeal cancer in Koreans by identifying the survival rate of lip-oral-pharyngeal cancer in Koreans through long-term big data. Material and Method: This study utilized 2023 KOSIS (Cancer Registration Statistics, Ministry of Health and Welfare) academically. The 5-year relative survival rates of lip-oral-pharyngeal cancer from 1996 to 2020 were compared and analyzed at 5-year intervals. Results: The 5-year relative survival rate for lip-oral-pharyngeal cancer was 47.4% from 1996 to 2000, 54.5% from 2001 to 2005, 61.1% from 2006 to 2010, 65.5% from 2011 to 2015, and 69.7% from 2016 to 2020. From 1996 to 2005, the 5-year relative survival rate for lip-oral-pharyngeal cancer was higher than the 5-year relative survival rate for all cancers. However, in the recent 15 years from 2006 to 2020, the 5-year relative survival rate for lip-oral-pharyngeal cancer was lower than for all cancers. Conclusions: In conclusion, this long-term big data showed that the 5-year relative survival rate of lip-oral-pharyngeal cancer in Koreans has increased further in modern times. However, in order to increase the overall survival rate of all human cancers, continuous efforts to improve the survival rate of lip-oral-pharyngeal cancer are needed in the future.

Currently, Korea is considering a disposal system based on Sweden’s KBS-3 model to dispose of high-level waste. The disposal system uses a multi-barrier concept to protect high-level waste with canister, buffer, backfill, and natural rock. In Korea, copper and iron are being considered for external and internal canisters, and bentonite is being considered as a buffer material. This is a similar choice to many overseas disposal systems. However, unlike the rolling, extrusion, and forging manufacturing methods being considered overseas for manufacturing external canister, domestic research is currently underway on manufacturing external copper canister using cold spray coating. The canister manufacturing method may vary depending on unit cost and manufacturing convenience. However, the properties of metal vary slightly depending on the manufacturing method of the metal. In this case, the characteristics of the canister may vary slightly depending on the canister manufacturing method, and eventually the corrosion resistance may also vary slightly. In order to understand how the copper canister manufacturing method affects corrosion resistance, corrosion rates were calculated and compared through electrochemical corrosion experiments at domestic groundwater ion concentration.

It is very important that the confinement of a spent fuel storage systems is maintained because if the confinement is damaged, the gaseous radioactive material inside the storage cask can leak out and have a radiological impact on the surrounding public. For this reason, leakage rate tests using helium are required for certificate of compliance (CoC) and fabrication inspections of spent fuel storage cask. For transport cask, the allowable leakage rate can be calculated according to the standardized scenario presented by the IAEA. However, for storage cask, the allowable leakage rate is determined by the canister, facility, and site specific information, so it is difficult to establish a standardized leakage rate criterion. Therefore, this study aims to establish a system that can derive system-specific leakage test criteria that can be used for leakage test of actual storage systems. First, the variables that can affect the allowable leakage rate for normal and accident conditions were derived. Unlike transportation systems, for storage systems, the dose from the shielding analysis and the dose from the confinement analysis are summed up to determine whether the dose standard is satisfied, and even the dose from the existing nuclear facilities is summed up during normal operation condition. For this reason, the target dose is used as an input variable when calculating the allowable leakage rate for the storage system. In addition, the main variables are the distance from the boundary of the exclusive area, the number of cask, the inventory of nuclide material in the cask, the free volume, and the internal and external pressure. Utilizing domestic and US NRC guidelines, we derived basic recommended values for the selected variables. The GASPARII computer code that can evaluate the dose to the public under normal operating conditions was utilized. Using the above variables, the allowable leakage rate is calculated and converted to the allowable criteria for helium leakage rate test. The developed system was used to calculate the allowable leakage rate for normal and accident conditions for a hypothetical storage system. The leakage rate criteria calculation system developed in this study can be useful for CoC and fabrication inspections of storage systems in the future, and a GUI-based program will be built for user convenience.

Considering the domestic situation where all nuclear power plants are located on seaside, the interim storage site is also likely to be located on coastal site. Maritime transportation is inevitable and the its risk assessment is very important for safety. Currently, there is no independently developed maritime transportation risk assessment code in Korea, and no research has been conducted to evaluate the release of radioactive waste due to the immersion of transport cask. Previous studies show that the release rate of radionuclides contained in a submerged transport cask is significantly affected by the area of flow path generated at the breached containment boundary. Due to the robustness of a cask, the breach is the most likely generated between the lid and body of cask. CRIEPI investigated the effect of cask containment on the release rate of radioactive contents into the ocean and proposed a procedure to calculate the release rate considering the socalled barrier effect. However, the contribution of O-ring on the release rate was not considered in the work. In this study, test and analysis is performed to determine the equivalent flow path gap considering the influence of O-rings. These results will be implemented in the computational model to assess sea water flow through a breached containment boundary using CFD techniques to assess radionuclide release rates. To evaluate the release rate as a function of lid displacement, a small containment vessel is engineered and a metal O-ring of the Helicoflex HN type is installed, which is the most commonly used one in transport and storage casks. The lid of containment vessel is displaced in vertical and horizontal direction and the release rate of the vessel was quantified using the helium leak test and the pressure drop test. Through this work, the relationship between the vertical opening displacement and horizontal sliding displacement of the cask lid and the actual flow path area created is established. This will be implemented in the CFD model for flow rate calculation from a submerged transport cask in the deep sea. In addition, the compression of the O-ring causes very small gaps, such as capillaries. In these cases, Poiseuille’s law is used to calculate the capillary flow rate.

Given the situation in the Republic of Korea that all nuclear power plants are located at the seaside, the interim storage facility is also likely to be located at seaside and the maritime transportation of Spent Nuclear Fuel is considered inevitable. The Republic of Korea does not have an independently developed maritime transportation risk assessment code, and no research has been conducted to evaluate the release rate of radionuclides from a submerged transportation cask in the sea. Therefore, there is a need to develop a technology that can assess the impact of immersion accidents and establish a regulatory framework for maritime transportation accidents. The release rate of radionuclides should be calculated from the flow rate through a flow path in the breached containment boundary. According to the cask design criteria, it is anticipated that even under severe accident conditions, the flow path size will be very small. Previous studies have evaluated fluid flow passing through micro-scale channel by integrating internal and external flows within and around a transport cask. As part of the evaluation, a comprehensive “Full-Field Model” incorporating external flow fields and a localized “Local-Field Model” with micro-scale flow paths were constructed. Sub-modeling techniques were employed to couple the flow field calculated by the two models. The aforementioned approach is utilized to conduct the evaluation of fluid flow passing through micro-scale flow paths. This study aims to evaluate fluid flow passing through micro-scale flow paths using the aforementioned CFD (Computational Fluid Dynamics) method and aims to code the findings. The Gaussian Process Regression technique, a machine learning model, is utilized for developing a mathematical metamodel. The selected input parameters for coding are organized and their respective impacts are analyzed. The range of these selected parameters is tailored to suit domestic environments, and computational experiments are planned through Design of Experiments. The flow path size is included as an input parameter in the coded model. In cases where the flow path size becomes extremely small, making it impractical to use CFD techniques for calculations, Poiseuille’s law is employed to calculate the release rate. In this study, a model is developed to evaluate the release rate of radionuclides using CFD and mathematical equations covering the whole possible range of flow path size in a lost cask in the deep sea. The model will be used in the development of a maritime transportation risk assessment code suitable for the situation and environment in Korea.

The need for lightweight yet strong materials is being demanded in all industries. Carbon fiber-reinforced plastic is a material with increased strength by attaching carbon fiber to plastic, and is widely used in the aerospace industry, ships, automobiles, and civil engineering based on its low density. Carbon-reinforced fiber plastic is a material widely used in parts and manufactured products, and structural analysis simulation is required during design, and application of actual material properties is necessary for accurate structural analysis simulation. In the case of carbon-reinforced fiber plastics, it is reported that there is a porosity of around 0.5% to 6%, and it is necessary to check the change in material properties according to the porosity and pore shape. It was confirmed by applying the method. It was confirmed that the change in elastic modulus according to the porosity was 10.7% different from the base material when the porosity was 6.0%, and the Poisson's ratio was confirmed to be less than 3.0%. It was confirmed that the elliptical spherical pore derived different material properties from the spherical pore depending on the pore shape, and it was confirmed that the shape of the pore had to be confirmed to derive equivalent material properties.

The blockage rate for three kinds of nets commonly used in agricultural facilities was assessed by using the image acquisition and its relevant processing. By using both empirical relations presented by Idel’chik and Richards and Robinson, and the blockage rate obtained from the image processing, the pressure drop through the nets was predicted and also compared with wind tunnel experiment results. The results of the study showed that the blockage rate of the net was discriminated according to such factors as the magnitude of nets, the existence of inside threads, the thickness and number of threads. In addition, the blockage rate for the incident angle of 0° when the wind blew at the front had the range of 0.22－0.29 (0.22－0.32 when considering whole incident angles from 0° to 45° by 15°). For the nets with the blockage rate of about 30% or below, the prediction by the empirical relations of by Idel’chik and Richards and Robinson showed a little higher pressure drop overall than that of the wind tunnel test, but the use of the empirical relations and the blockage rate could be thought of as providing effectively meaningful guidelines for the safe design of agricultural facilities including nets because the wind tunnel test has been tedious and expensive. Further research and potential application on the prediction technique of the pressure drop, regarding both a subtle deformation by the wind and manufacturing methods with regard to the level of knots and the existence of inside threads, needs to be done for the nets with higher blockage rate.

남강댐 하류역에 위치한 사천만, 진주만, 강진만에서 가화천 방류에 따른 담수 배제의 분배 특성을 평가하기 위하여 입자추적 수치실험을 실험하였다. 가화천을 통해 3개의 방류조건(무방류, 강우시 방류, 홍수시 방류)에서 입자 1000개를 투여하여 노량수도, 대방수 도, 창선해협으로 빠져나가는 입자의 수를 비교하였다. 가화천을 통한 방류량이 늘어날수록 노량수도로의 입자 분배율이 증가하고, 대방 수도로의 분배율이 감소하는 것을 확인할 수 있었다. 즉, 평소에는 가화천 하류에 위치한 물질의 약 95%가 대방수도를 통해 빠져나가다 가, 강우에 의해 남강댐의 방류량이 증가하면서 노량수도로의 분배율이 증가하며, 홍수시에는 노량수도로의 입자 분배율이 45.5% 까지 증가하는 것을 확인할 수 있었다.

아메리카동애등에 성충은 음식물 폐자원 등 유기물이 있는 곳에 알을 낳는 습성이 있다. 대부분의 농가는 음식 물폐자원을 가공한 단미사료(습식사료)를 유인배지로 활용하여 그 위에 플로랄폼(오아시스)를 놓고 알을 받는 다. 그러나 플로랄폼은 재사용이 불가하고 생분해되지 않는 환경폐기물로서 처리가 곤란하며 포름알데하이드, 카본 블랙 등의 발암물질을 함유한 것으로도 알려져 있다. 이에 본 연구는 먹이원 자체를 활용하여 폐기물이 발생하지 않는 친환경 산란받이를 개발하였으며 일회용으로 사용되는 플로랄폼을 대체하였다. 먹이원으로 활 용할 수 있는 습식사료와 건식사료를 주재료로 하여 제작하며, 습식사료(수분60~80%)와 건식사료(1~10%)를 1:0.5~1 비율로 혼합한 사료 혼합물과 보조첨가제와 물을 포함하여 제작한다. 친환경 산란받이는 기존 플로랄폼 대비 산란율이 34% 증가하였으며 구매비용 또한 75% 절감하였다.