Domestic commercial low- and intermediate-level radioactive waste storage containers are manufactured using 1.2 mm thick cold-rolled steel sheets, and the outer surface is coated with a thin layer of primer of 10~36 μm. However, the outer surface of the primer of the container may be damaged due to physical friction, such as acceleration, resonance, and vibration during transportation. As a result, exposed steel surfaces undergo accelerated corrosion, reducing the overall durability of the container. The integrity of storage containers is directly related to the safety of workers. Therefore, the development of storage containers with enhanced durability is necessary. This paper provides an analysis of mechanical properties related to the durability of WC (tungsten carbide)-based coating materials for developing low- and intermediate-level radioactive waste storage containers. Three different WC-based coating specimens with varied composition ratios were prepared using HVOF (high-velocity oxy-fuel) technique. These different specimens (namely WC-85, WC-73, and WC-66) were uniformly deposited on cold-rolled steel surfaces ensuring a constant thickness of 250 μm. In this work, the mechanical properties of the three different WCbased coaitng materials evaluated from the viewpoints of microstructure, hardness, adheision force between substrate and coating material, and wear resistance. The cross-sectional SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) images revealed that elements W (tungsten), C (carbon), Ni (nickel), and Cr (chromium) were uniformly distributed within the each coating layers which was approximately 250 μm thick. The average hardness values of HWC-85 and HWC-73 were found to be 1,091 Hv (Vickers Hardness) and 1,083 Hv, respectively, while the HWC-66 exhibited relatively lower hardness value of 883 Hv. This indicates that a higher WC content results in increased hardness. Adhesion force between and substrates and coating materials exceeded 60 MPa for all specimens, however, there were no significant differences observed based on the tungsten carbide content. Furthermore, a taber-type abrasion tester was used for conducting abrasion resistance tests under specific conditions including an H-18 load weight at 1,000 g with rotational speed set at 60 RPM. The abrasion resistance tests were performed under ambient temperatures (RT: 23±2°C) as well as relative humidity levels (RH: 50±10%). Currently, the ongoing abrasion resistance tests will include some results in this study.

This study focuses on the development of coatings designed for storage containers used in the management of radioactive waste. The primary objective is to enhance the shielding performance of these containers against either gamma or neutron radiation. Shielding against these types of radiation is essential to ensure the safety of personnel and the environment. In this study, tungsten and boron cabide coating specimens were manufactured using the HVOF (High-Velocity Oxy Fuel) technuqe. These coatings act as an additional layer of protection for the storage containers, effectively absorbing and attenuating gamma and neutron radiation. The fabricated tungsten and boron carbide coating specimens were evaluated using two different testing methods. The first experiment evaluates the effectiveness of a radiation shielding coating on cold-rolled steel surfaces, achieved by applying a mixture of WC (Tungsten Carbide) powders. WC-based coating specimens, featuring different ratios, were prepared and preliminarily assessed for their radiation shielding capabilities. In the gamma-ray shielding test, Cs-137 was utilized as the radiation source. The coating thickness remained constant at 250 μm. Based on the test results, the attenuation ratio and shielding rate for each coated specimen were calculated. It was observed that the gammaray shielding rate exhibited relatively higher shielding performance as the WC content increased. This observation aligns with our findings from the gamma-ray shielding test and underscores the potential benefits of increasing the tungsten content in the coating. In the second experiment, a neutron shielding material was created by applying a 100 μm-thick layer of B4C (Boron Carbide) onto 316SS. The thermal neutron (AmBe) shielding test results demonstrated an approximate shielding rate of 27%. The thermal neutron shielding rate was confirmed to exceed 99.9% in the 1.5 cm thick SiC+B4C bulk plate. This indicates a significant reduction in required volume. This study establishes that these coatings enhance the gamma-ray and neutron shielding effectiveness of storage containers designed for managing radioactive waste. In the future, we plan to conduct a comparative evaluation of the radiation shielding properties to optimize the coating conditions and ensure optimal shielding effectiveness.

APro, a modularized process-based total system performance assessment framework, was developed at the Korea Atomic Energy Research Institute (KAERI) to simulate radionuclide transport considering coupled thermal-hydraulic-mechanicalchemical processes occurring in a geological disposal system. For reactive transport simulation considering geochemical reactions, COMSOL and PHREEQC are coupled with MATLAB in APro using an operator splitting scheme. Conventionally, coupling is performed within a MATLAB interface so that COMSOL stops the calculation to deliver the solution to PHREEQC and restarts to continue the simulation after receiving the solution from PHREEQC at every time step. This is inefficient when the solution is frequently interchanged because restarting the simulation in COMSOL requires an unnecessary setup process. To overcome this issue, a coupling scheme that calls PHREEQC inside COMSOL was developed. In this technique, PHREEQC is called through the “MATLAB function” feature, and PHREEQC results are updated using the COMSOL “Pointwise Constraint” feature. For the one-dimensional advection-reaction-dispersion problem, the proposed coupling technique was verified by comparison with the conventional coupling technique, and it improved the computation time for all test cases. Specifically, the more frequent the link between COMSOL and PHREEQC, the more pronounced was the performance improvement using the proposed technique.

The slaughter of livestock is inevitably required to obtain meat products from livestock. Since slaughter means pain and death for animals, reducing the pain and distress of animals during slaughter is very important from a perspective of animal welfare based on the principle of respect for life. Generally, two stunning methods, CO2 stunning and electrical stunning, are used for slaughter. When the carotid arteries of the lungs are cut off for bleeding, the bronchial tubes are also severed. To determine the degree of blood inflow into the lungs through the severed bronchial tubes, the prevalence rates of pulmonary diseases and pulmonary congestion in slaughtered pigs were analyzed. In this study, the prevalence of pneumonia was 24.9% in Slaughterhouse A using the gas method, but it was decreased by about 10% to 15.7% and 12.6%, respectively, in Slaughterhouses B and C using the electric method. On the other hand, the prevalence of pulmonary congestion in Slaughterhouses A, B, and C was 4.24%, 14.10% and 16.40%, respectively. In other words, the prevalence of pulmonary congestion was higher by about 10% in the groups of pigs slaughtered by the electric method (Slaughterhouses B and C) than in the group of pigs slaughtered by the gas method (Slaughterhouse A). These results indicate that blood inflow into the pulmonary alveoli led to a diagnosis of pulmonary congestion instead of pneumonia in some pigs with pneumonia. In short, it was found that about 10% of pigs stunned by the electric method were not in a state of complete unconsciousness but in a partially conscious state during slaughter. It is suggested that slaughterhouses should be equipped with gas stunning equipment instead of applying the electric method due to lower costs.

APro, a modularized framework of the process-based total system performance assessment, has been developed by KAERI to simulate the radionuclide transport in geological disposal system considering multi-physics phenomena. However, the target problem including more than 10,000 boreholes and over 100,000 years of simulation time is computationally challenging to deal with numerical solvers provided by COMSOL Multiphysics constituting APro. To alleviate the computational burden, machine learning (ML) techniques have been studied to develop a surrogate model replacing the heavy computation part. In recent studies, attempts have been made to integrate the knowledge of physics and numerical methods into the ML model for partial differential equations (PDEs). Unlike conventional ML approaches solely relying on data-driven method, the integration can help to make the ML model more specialized for solving PDEs. The hybrid neural network (NN) solver method is one of the strategies to develop more efficient PDE solver by interleaving NN with numerical solvers like finite element method (FEM). The hybrid NN model on the premise of numerical solver is easier to train and more stable than the purely data-driven model. For example, one previous study has used the hybrid NN model as a corrector for an incomplete numerical solver for the advection-diffusion problem. In every time step of simulation, NN corrects the error of incomplete solution obtained by a relaxed numerical solver with coarse meshing. The simulation in the next time step starts from the corrected solution, so NN interacts with the numerical solver iteratively. If the corrector is successfully trained, the incomplete but fast solver with corrector can provide reliable results comparable to the original massive solver. This study adopts the hybrid concept to develop a surrogate model for the near-field region, which is the heavy computation part in the simulation of geological disposal system. Various incomplete models such as coarse meshing or emptying the borehole domain are studied to construct a hybrid NN solver. This study also covers how to embed the hybrid NN in COMSOL Multiphysics to train and use it during the simulation.

본 연구는 원통형 종이포트 토마토 육묘시 Diniconazole의 처리방법이 도장억제 및 근권발달에 미치는 영향을 검토하기 위하여 수행되었다. 그 결과, 엽면적, LAR, 초장, 충실도, 생체중, RGR 및 R/S 에서 시험구간 유의한 차이를 보였다. 동일한 농도를 처리했을 경우, 근권부와 지상부의 흡수도 차이로 인해 저면관수가 엽면살포에 비해 도장억제에 효과적이었다. 저면관수는 엽면시비의 10분의 1의 농도만으로도, 20~30%정도의 동일한 도장억제 효과를 얻을 수 있었다. 디니코나졸 처리에의한 근권부 반응이 흥미로웠는데, 저면관수시 총근장, 근권부피, 평균 근경 및 근단수가 증가하였다. 특히, 0.3mm 이하의 초미세근이 감소하고 0.3~0.6mm의 세근이 증가하였다. 따라서 원통형 종이포트 육묘시 저면관수를 하는 것이 기존 엽면시비에 비해 사용량이 적으면서도 도장억제 및 근권부 활착률을 높힐 수 있을 것으로 판단된다.

The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that the proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.

The International Organization for Standardization (ISO) published ISO 9001 Quality Management System (QMS)-Requirements in 1987 and has revised four times since then. ISO 9001:2015 is the latest edition. This latest edition has two most noticeable changes. The first major change of new edition focuses on performance with an emphasis on Risk-Based Thinking (RBT) to enhance the process approach. The new edition consists of ten clauses whose first three clauses are largely same as older edition but risks are clearly stated and stressed in last seven clauses, emphasizing on Plan-Do-Check-Act cycle at all levels in the organization. The second major change is that the new edition has the same overall structure as other ISO management system standards known as High Level Structure (HLS) with Annex SL. The companies obtained the certificate of new ISO 9001:2015 QMS by September 15, 2018 in order to maintain as an ISO QMS registered firm. In this article we collected transition audit data from more than 100 companies that registered ISO 9001:2015 QMS for recent three years. We performed a statistical analysis to disclose the relationships between the characteristics of companies and the minor nonconformities found in ISO 9001:2015 requirements during transition audit processes. We also aim to interpret the findings and deduce the implications of the statistical results.

목적: 스마트 안경은 안경과 웨어러블 전자기기의 효과적인 융합을 잘 보여주는 어플리케이션이다. 스마 트 안경의 더 발전한 형태로, 전압에 의해 능동적으로 변색되는 안경의 제조도 가능할 것으로 기대된다. 따라서, 졸-겔 법에 의한 전기 변색 박막의 제조 과정에서 퍼콜레이션(percolation) 이론을 도입하여, 최적의 aging 조건을 찾아 전기 변색 코팅 박막 제조의 토대가 되고자 한다. 방법: 졸-겔 법을 이용하여 육 염화 텅스텐과 에탄올을 혼합하여 전기 변색 용액을 제조하였다. Aging에 따른 용액의 특성을 분석하고, ITO glass위에 전기 변색 박막을 코팅한 후, 리튬이온 기반 전해질을 이용하여 전기 변색 특성을 확인하였다. 결과: 졸-겔법으로 제조된 전기 변색 용액은 aging에 따라 텅스텐과 산소의 결합이 달라지며, 이것을 적 외선 분광법으로 분석하였다. WO3/ITO glass의 가시광선 전 영역의 광 투과도(시감 투과도)를 측정한 결과, aging에 따라 변색효율의 차이를 보였다. 또한, percolation이 충분히 진행되기 전 샘플의 경우, 광 투과도 가 착색 시 43.0 %, 탈색 시 63.6 %로 1.10의 가장 높은 광밀도를 보였다. 또한, aging이 충분히 진행된 후의 샘플은 착색 시 광 차단 효과가 좋은 결과값을 보였다. 결론: 졸-겔 법에 의해 제조된 변색 용액으로 전기 변색 유리를 제작하였을 때, 용액의 aging에 따라 광 학적 특성이 달라짐을 확인하였다. 긴 시간 aging하는 경우, 변색 효율을 가늠하는 광밀도가 감소하였다. 따라서, 변색효율이 좋은 렌즈가 필요한 경우, percolation 임계 점 이하의 aging 시간이 짧은 용액을 사용 하는 것이 좋으며, 진한 착색이 필요한 광학 샘플이 필요한 경우는 긴 시간 에이징한 용액으로 코팅막을 제 조하는 것이 좋을 것으로 판단된다. 이러한 코팅 박막에 대한 기초 조건의 연구가 향후 스마트 안경 등의 제작 시 참고가 될 것으로 기대된다.

We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.

This study was conducted to estimate the effect of home or hetero fermentative lactic acid bacteria(LAB) on chemical composition, fermentation quality, and aerobic stability of rye silage. Rye forage was harvested at dough stage(28.9% of dry matter), chopped to 3-5 cm length, and divided into 4 piles for different inoculations as treatment, following 1) No additives(CON); 2) Lactobacillus plantarum at rate of 1.5 x 105 cfu/g of fresh forage(LP); 3) L. buchneri at rate of 1.2 x 105 cfu/g of fresh forage(LB); and 4) Mixture of LP and LB at 1:1 ratio(MIX). Rye silage was ensiled into 20 L bucket silo in quadruplicate for 0, 1, 4, 7, and 100 day periods. After 100 days of ensiling, the silage treated with LB had lower acid detergent fiber content(p<0.05), but higher in vitro dry matter digestibility(p<0.05). The LB and MIX reduced (p<0.05) pH more rapidly than CON and LP across the ensiling days, but had no difference on 100 days. Silage treated LP had lowest(p<0.05) acetic acid, but highest(p<0.05) propionic acid. In contrast, LB treated silage had highest(p<0.05) acetic acid, but lowest(p<0.05) propionic acid with the absence of butyric acid. On microbial count, LP treated silage had lowest(p<0.05) LAB, yeast, and aerobic stability, whereas LB and MIX treated silages had highest(p<0.05). Mold was not detected across all silages. Therefore, it could be concluded that heterofermentative LAB solely or combo with homofermentative LAB might improve in vitro dry matter digestibility, fermentation characteristics, and aerobic stability of rye silage harvested at dough stage.

The objectives of this study were to evaluate the antimicrobial effects of ε-poly-L-lysine mixture (EPM) on cheon-ggukjang and to determine the optimal mixing ratio in cheonggukjang. Increasing the EPM up to 2% decreased via-ble cell counts at both 15oC and 30oC storage. The pH of cheonggukjang without EPM increased slowly over thestorage periods, but cheonggukjang with EPM showed a slight increasing tendency, with the highest pH at 2% EPM.The sensory scores, such as texture and flavor, were highest in samples containing 2% EPM; however, overall pref-erence was not significantly different when compared to the control. For the optimum cheonggukjang processingconditions, 13 experimental points were selected. Soybean and EPM were chosen as independent variables. Viablecell count, pH, texture, and overall preference were measured. The optimum formulation of cheonggukjang usingthe numerical analysis was found to be 98.52% soybean and 1.48% EPM, resulting in a 0.722 desirability value.

Environmental pollution including air, land, and water has become one of the most critical issues in global interest. The damages due to environmental pollution lead to serious disasters. Nations have realized the importance of environment protection and have been starting to force organizations to implement environmental management system (EMS) as way of protecting environment. ISO 14001 requirements that are the most popular standard as EMS have been developed to support continuous improvement to environment management. It has been revised once since publication and ISO 14001 : 2004 version is currently available. Organizations globally started to acquire the certificate of EMS to observe environment related laws, accept customers’ and stakeholders’ request, increase market share, and fulfill implementation motives. This article examines the audit data that were collected for several years from manufacturing companies including shipbuilding, machinery, metal, automobiles, and chemical companies in southeastern Korea on the basis of ISO 14001 : 2004 requirements. The audit data were classified into minor nonconformities based on factors such as business size, business type, and EMS implementation period. We conduct hypotheses test using statistical methods in order to see if there are any significant differences based on the factors. We draw conclusions for the results of hypotheses test and address the necessities of energy, greenhouse gas, green management, and continuous improvement to enhance the efficiency of EMS implementation.

Most patients with chronic low back pain experience functional disability of trunk muscle, and limitations in physical activity. While there are many types of exercise programs available, in recent years sling exercise has been emerging as the exercise program for spinal stabilization. It has been supported by a great amount of research with positive findings on its effectiveness. This research studies the effects of bridging exercise, conducted on a sling, on pain level and trunk muscle activation in supine, sidelying, and prone positions during a 4 weeks period. 10 healthy people(normal group, n=10) and 28 patients with low back pain participated in this study. 28 patients were divided into two groups; one group participated in exercise with the sling(experimental group, n=14) and the other group exercised without the sling(control group, n=14). They were asked to use the Numerical Rating Scale(NRS) to answer to the level of their pain they felt (no pain: 0 point, severe pain: 10 points). During sling bridging exercises, the muscle activity level in each muscle measured in each position was standardized as three seconds of EMG signals during five seconds MVIC. In conclusion, the experimental group with four weeks of sling bridging exercise experienced a statistically significant reduction in the pain level(p<.05) and increase in the muscle activities of erector spinae when in supine position, internal oblique when in sidelying position, and rectus abdominis in prone position(p<.05). Regular sling bridging exercise reduces the low back pain and enhances other trunk muscle activation, thereby positively affect spinal stabilization.

Cryopreservation of avian semen is a useful tool to preserve genetic resource for aim of preventing extinction induced by infectious disease like avian influenza. Unlike those of mammals, data from chicken cryopreserved semen has not been showed feasible results. So, various cryoprotectants and diluents have been examined in many methods. In this report, as a major ingredient of avian seminal plasm, glutamine was substituted by alanyl glutamine to enhance physiological stability of chicken semen during freezing. We studied effect of glycerol and Dimethylacetamide(DMA) on motility and progressive motility of spermatozoa using glutamine diluent(EK-G) or alanyl glutamine diluent(EK-A) condition. The semen of Ogye was collected twice a week by the dorso-abdominimal massage method and diluted with same volume of EK-G or EK-A at 25℃ and stored for 10 min at 4℃ in cold chamber. Glycerol or DMA was added to diluted semen to reached 7% of final concentration at 4℃. After 3min of equilibration, the diluted semen was packed into 0.25ml straws and subjected to cryopreservation used freezing equipment. The packed straw were placed on height 5 cm above surface of liquid nitrogen(LN2) and held for 10min. After preserved for 2 weeks, the straw was thawed onto the 4℃ cooling bath. The images of motility and progressive motility spermatozoa were recorded by digital image recorder and analyzed by manual. The results showed 68.5% motility and 34.1% progressive motility in DMA/EKA diluent, 31.45% and 17.6% in glycerol/EKA, 45.4% and 8.6% in DMA/EKG, and 9.7% and 6.4% in glycerol/EKG. With these results, the alanyl glutamine and DMA could be used as a main composition of diluent and cryoprotectant for cryopreservation of chicken semen.

목적: 500 mL 용량의 식염수가 한국에서는 콘택트렌즈 헹굼에 흔히 사용되고 있기 때문에 본 연구에서는 콘택트렌즈 착용자가 사용한 대용량 식염수의 미생물 오염과 관련된 위험 요인을 분석하였다. 방법: 120명의 소프트콘택트렌즈 착용자를 모집하고 식염수를 나누어 준 후 이들이 사용한 식염수를 수집하여 분석하였다. 사용한 식염수의 미생물 오염상태는 세균의 집락수 (colony-forming units)로 평가하였고, 세균의 종류는 유전자 중합효소반응(Polymerase Chain Reaction, PCR)으로 얻은 DNA 서열을 자동 염기서열분석기 및 BLAST 분석기를 이용하여 동정하였다. 식염수 오염에 영향을 미치는 요인은 카이제곱검정, 상관분석 및 다중회기분석으로 분석하였다. 결과: 수집된 식염수 중 45%가 세균에 오염되었으며 7종의 감염성 세균을 포함한 27종의 세균이 검출 되었다. 세균의 오염은 무방부제 식염수, 구멍이 뚫린 용기, 식염수 사용기간 및 렌즈착용 전의 손 세척 습관과 상관성이 있었다. 결론: 방부제가 포함된 식염수는 구멍이 뚫려있지 않은 용기에 적은 용량으로, 무방부제 식염수는 1회용으로 제조되어야 할 것이며, 콘택트렌즈 착용자에게는 관리방법에 대한 재교육이 필요할 것으로 사료된다.

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Margarodidae), is a destructive pest on citrus. This study was conducted to obtain the stage-specific phenology of I.purchasi for use in field application. The crawlers (hatched nymphs) from the egg sac of overwintered female began to move from late May and peaked in early to mid-June with most crawlers completed the movement till late June. The 1st nymph population peaked in mid June in 1stgeneration and early October in 2ndgeneration. The 2nd nymphs showed peak activity in late July and late October during the 1st and 2nd generation, respectively. The 3rd nymphs peaked in early September in 1st generation, while it kept a plateau without forming a peak after mid October in 2nd generation. The 1st generation adults peaked in mid September, and the tail was overlapped with 2nd generation adult population. Consequently, two life cycles were competed in Jeju area. An average of 20.7% of citrus orchards was infested with I. purchasi with a 3.9% of mean infested trees in Jeju. The present results should be useful in establishing management strategies for I. purchasi in citrus orchards.