PURPOSES : In this study, the alkali aggregate reactivity and expansion characteristics of mortar mixed with waste glass (a recycled aggregate) were confirmed to verify the alkali-silica reaction (ASR) stability and review the appropriateness of the alkali aggregate reactivity test method following the replacement of recycled aggregate. METHODS : The alkali-aggregate reactivity of waste glass aggregates was measured using the chemical and physical methods described in KS F 2545 and ASTM C 1260, respectively. The reactivity was classified by comparing the results. Cement with a high-alkali content was used to simulate an environment that can induce ASR. Non-reactive fine aggregates, waste glass fine aggregates, reactive general aggregates, and Ferronickel slag aggregates were used as control groups. RESULTS : Waste glass fine aggregates were classified as reactive when applying the chemical method. In the physical method, they were classified as reactive at 100% and latent reactive at 1%, based on the mixing ratio. Additionally, we discovered that the reliability of the chemical method was low since the ASR of the aggregates was classified differently based on the evaluation method, while the results of the chemical and physical test methods were inconsistent. CONCLUSIONS : To determine the alkali reactivity of recycled aggregates, the complex use of chemical and physical methods and analysis based on the mixing ratio of the reactive aggregates are required. Small amounts of waste glass aggregate replacements affected the ASR. Because ASR reaction products can affect the long-term thermal expansion of the structure, further research is needed to use ASR aggregates in structures.

The physical and antibacterial properties of ophthalmic lenses fabricated by copolymerization with hydrogel monomers using two types of graphene were measured, and their usability as contact lens materials was analyzed. For polymerization, silicone monomers, including SID-OH, 3-(methacryloxy)propyl tris(trimethylsiloxy)silane, and decamethylcyclopentasiloxane, were used, and N,N-dimethylacetamide, ethylene glycol dimethacrylate as a crosslinking agent, and azobisisobutyronitrile as an initiator were added. Also, graphene oxide nanoparticle (GON) and graphene nanoplate (GNP) were used as an additive, and the physical properties of the lenses fabricated after copolymerization were evaluated. The fabricated lenses satisfied the basic physical properties of general hydrogel contact lenses and showed the characteristics of lenses with high water content, and the disadvantage of very weak durability, due to low tensile strength. However, it was confirmed that the tensile strength and antibacterial properties were greatly improved by adding GON and GNP. With GON, the oxygen permeability and refractive index of the fabricated lenses were slightly improved. Therefore, it was determined that the graphene materials used in this study can be used in various ways as a contact lens material.

Background: After the coronavirus disease 2019 (COVID-19) pandemic, many changes in education were observed, particularly non-face-to-face classes. Many studies have focused on the suitability of non-face-to-face classes and the satisfaction of both students and teachers with this teaching method. However, no study on the suitability of numerous teaching methods in teaching physical therapy subjects has been conducted. Objectives: To investigated the suitability of three teaching methods, namely, face-to-face, non-face-to-face, and mixed classes, in teaching physical therapy subjects. Design: Survey research. Methods: 336 students studying physical therapy participated. A survey was conducted on the suitability of face-to-face, non-face-to-face, and mixed classes for 16 subjects. The survey was conducted using a Google questionnaire. Results: Face-to-face classes were found to be suitable for teaching the basic fields of physical therapy, and face-to-face and mixed classes were suitable for teaching the principle of diagnostic evaluation. Furthermore, faceto- face classes were found to be suitable for teaching physical therapy interventions. In other subjects, face-to-face classes were suitable for teaching rehabilitation medicine, non-face-to-face classes were suitable for teaching medical terms, and mixed classes were suitable for teaching daily life activities. Conclusion: The results of this study can be used as a basis for choosing the appropriate methods for learning and teaching physical therapy subjects.

이 연구는 생태형 해양스포츠의 체육교육 적용을 위한 지식구조를 구성하는 것에 목적이 있다. 구체적인 종목으로는 배구형 게임인 비치발리볼과 바다수영이 설정되었으며 연구수행을 위하여 지식구조 분석틀을 활용하였다. 연구의 타당성을 확보하기 위하여 전문가협의를 실시하였다. 연구결과는 다음과 같 다. 첫째, 2022개정 체육과 교육과정 시안에 기반한 지식구조를 마련하였다. 둘째, 생태형 해양스포츠의 체 육수업 적용 기반을 마련하였다.셋째, 비치발리볼의 지식․이해 영역, 과정․기능 영역, 가치․태도 영역의 학습 내용을 제안하였다. 넷째, 바다수영의 지식․이해 영역, 과정․기능 영역, 가치․태도 영역의 학습 내용을 제안 하였다. 이 연구는 향후 도입될 2022개정 체육과 교육과정의 실현된 모습을 미리 대비하였다는 것에 의미 가 있다.

This study collected powder extinguishers with 6-10 years of elapsed life from January 2012 to January 2017 in market, factory, and apartment areas to experiment with changes in fineness and to examine the characteristics of extinguishing power. First, in the case of ABC powder, 98.3 wt% of the 8-year market area and 98.6 wt% of the 10-year apartment complex were found to be inappropriate in the first, second, and third arithmetic average analysis of the powder extinguisher from 6 to 10 years. That is, the fine distribution and size of the powder extinguishing agent particles should be managed within an appropriate range. It is analyzed that the powder fire extinguisher may experience a change in the fineness of the powder depending on the external environment exposure, placement, management status, and age of use, resulting in a decrease in digestive power or inability to radiate. Second, the fire extinguisher cannot be used in the initial fire suppression depending on the place of deployment, the environment of deployment, the progress of the number of years of use, and maintenance, so it is necessary to strengthen the device that enables fire extinguisher maintenance and inspection. Third, in the manufacturing process, the charging method should also be reviewed in consideration of the conditions of the workplace, the humid season, and the rainy environment.

본 연구는 한국에서 예체능 계열 박사 과정에 재학 중인 중국인 유학생들의 교육 현황을 조사하고 분석하여, 한국 대학의 외국인 유학생 모집부터 교육에 이르기까지 합리적인 개선과 유용한 유학 정보를 제공하고자 한다. 본 연구의 목적을 달성하기 위해 다음과 같은 연구 절차를 거쳤다. 먼저, 한국 대학의 예체능 계열 박사 과정에 재학 중인 중국인 유학생들이 선호하는 사립 대학 상위 3곳을 선정하여 이들 대학의 학과, 전공 구분, 입학 요건, 지원 절차, 장학금 혜택 등의 내용을 분석하였다. 다음으로 인터뷰와 설문을 통해 예체능 계열 박사 과정 중국인 유학생들의 대학 선택 요인, 일상 및 학교생활 현황, 학습 상태, 학습 만족도, 한국어 능력 수준, 논문 진행 등의 교육 현황을 파악하였다. 이에 도출된 결과는 다음과 같다. 첫째, 학교 지원 절차, 중국인 유학생 수, 어학 성적 여부 그리고 지인과 유학 중개소의 추천을 대학 선택의 선결 조건으로 생각하기 때문에 대학교에서 유학생 모집 홍보, 한국과 중국 학교의 교류 프로그램 및 연합 과정 개설 등을 적극적으로 고려해야 한다. 둘째, 한국어 능력이 부족하여 일상, 학교생활에 불편한 데가 많다는 조사 결과에 따라 학교 측은 유학생들의 원활한 언어 소통에 관한 적극적인 지원과 도움이 필요하다고 판단된다. 셋째, 모든 교과목의 타당성과 전문성은 높은 반면, 실용성은 상대적으로 낮은 편이기 때문에 예체능 계열의 특수성을 고려한 맞춤형 한국어 연계 교과목의 개설이 매우 필요하다. 넷째, 논문의 진행에 있어 어느 정도의 한국어 실력을 갖추어야 하는 상황이므로 해당 학과에 속하거나 전문 용어를 통역할 수 있는 실력을 갖춘 통역자가 논문 통역을 담당해야 한다. 다섯째, 논문 작성 프로그램이나 사이버 시스템의 사용법을 가르치는 수업이 매우 필요하다. 이뿐만 아니라 유학생들이 희망하는 한·중 교류프로그램 등을 만들어 일상과 학교생활을 풍부하게 하고 불안감을 약화시킬 수 있다고 생각된다. 저자는 현재 한국 대학 외국인 박사 과정 모집에 있어, 언어 능력이 떨어지는 학생들을 선발하는 것이 본질적인 문제라고 생각한다. 그러나 각 대학의 운영 및 모집에 있어 실제적인 해결이 어렵다고 본다. 이를 본 연구의 한계점으로 보고, 가장 현실적인 상황을 고려하여 예체능 계열 중국인 유학생들의 교육 환경, 수업 설계, 학생 지원, 혜택 및 학습 방향과 관련된 근본적이고 구체적인 방안을 제공하였다. 본 연구가 한국의 고등 교육 기관의 외국인 유학생 모집 시스템 구축, 입시 그리고 유학생 교육, 지원 등 상황에 따른 교육 개선과 발전에 보다 유용한 자료로 활용되기를 바란다.

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.

Bentonite containing >50wt% montmorillonite is being considered as a buffer material in a deep geological repository to dispose of high-level radioactive wastes (HLRW). Bentonite is considered a buffer material because of its exceptional properties such as high swelling capacity, low hydraulic conductivity, and high radionuclide sorption capacity. The bentonite buffer can be exposed to heat from the radioactive decay of HLRW and to groundwater. Water in bentonite buffer can be converted to steam under elevated temperature and pressure conditions. Previous studies reported contrasting results showing that steam treatment could decrease the swelling capacity due to changes in the surface properties from hydrophilic to hydrophobic or could not change. The contrasting results were probably because different studies used different experimental conditions and methods. Therefore, the effect of steam treatment on the bentonite properties is still unclear. The purpose of this study is to determine how the bentonite properties change after steam treatment, in particular swelling and hydrophilic properties. Two types of bentonite were used for steam treatment and analysis; Gyeongju Ca-bentonite (KJ- II) and Wyoming Na-bentonite (GCL-B). Steam treatment was performed at 150°C in an oven for various periods (7, 30, 60, and 90 days). Free swell test, X-ray fluorescence (XRF) analysis, surface-area measurement (BET), thermal gravimetric analysis (TGA), cation exchange capacity (CEC), and water uptake test were performed on steam-treated bentonite for various periods and raw bentonite. After steam treatment, some properties of steam-treated bentonite changed when compared to raw bentonite. Free swell index, which means the swelling capacity, decreased significantly as the results of previous studies. CEC and BET surface area values depended on the bentonite type. For Wyoming Na-bentonite, in which the dominant interlayer cation is a monovalent cation, CEC and BET surface area values were increased. On the other hand, Gyeongju Ca-bentonite, in which the dominant interlayer cation is a divalent cation, has no change in the above two properties. Results of XRF analysis, TGA, and water uptake test showed that these properties of both bentonites did not change after steam treatment. The results of this study confirmed that steam treatment affected the swelling and physicochemical properties of bentonite, in particular Na-bentonite. Further studies will focus on the surface properties of bentonite to investigate whether the surface properties have changed from hydrophilicity to hydrophobicity, or whether the montmorillonite structure has changed.

Domestic nuclear facilities establish a physical protection system to respond to illegal transfer of nuclear materials and sabotage to nuclear materials and nuclear facilities, and operate a security search system in order to prevent the entry of controlled items into the facility. X-ray security search is also the most widely used for such security search. Since 2018, Korea Institute of Nuclear Nonproliferation and Control (KINAC) has developed the “X-ray security screening Web-Based Training Program (XWBT)” and has been using it in the physical protection education. The XWBT contains about 700 X-ray images of the item, and can learn X-ray images by type or package of the item. In addition, trainees can practice reading the X-ray image of the item or package, looking for controlled items, and determining whether the item could be passed or opened. However, there is a limit to Web-Based X-ray training program alone. This is because even if the same item is contained in the same bag, the X-ray image could be varied depending on the direction, angle, and other items in the package. Therefore, in addition to XWBT, X-ray reading practice education for actual luggage should be conducted in parallel. In addition, trainees should be familiar with various images through repetitive X-ray reading practice training so that they should be able to intuitively read X-ray images and find controlled items. Therefore, securing educational time is essential to produce skilled trainees. Korea Aviation Security Academy (KASA), which produces professional security inspectors, has established and operated a “Security search education filed for actual luggage” where trainees can pack their own bags, read X-ray images, and practice whether there are controlled items packed. In addition, KASA provides 40-hour training for security search personnel, which focuses on improving the practical skills that security search personnel must have. This study describes the current status of “X-ray Security Search” of Physical Protection Education for security personnel and presents course improvements through the case of KASA.

Sabotage on nuclear power plants are of great national and social significance and long-term damage, the IAEA’s “Nuclear Security Recommendations on Physical Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Rev.5) provides a standard direction for physical protection of their nuclear facilities in almost all member countries, including Korea and the United States. In the United States, Federal Law 10 CFR Part 73, Sections 73.40 to 73.57 specify requirements for physical protection of nuclear power plants, performance criteria, physical protection systems and components thereof, core information, and physical protection for key activities related to nuclear power plant operations. Accordingly, the USNRC carefully examines whether the plant meets the physical protection objectives and criteria set out in SRP 13.6.2, whether the core area/protection area is properly set up to protect against internal and external physical attacks, sabotage threats, and what design measures and facilities are being set up for these areas. The Department of Homeland Security (DHS), established in 2002 following the 2001 World Trade Center attacks, authorized federal, local governments, and authorities National Infrastructure Protection Plan (NIPP) to protect facilities from terrorist attacks and man-made physical attacks in 2007. NIPP clarifies the great principles and governance of the physical protection of national infrastructure in the United States presented by DHS. There are many physical protection design guidelines and technical standards for preventing attacks from terrorists or internal and external sabotage attackers, improving the viability of mitigating the damage in case of emergency, and achieving efficient recovery from such damage. Particularly important, small-scale damage/damage at a particular location of a major facility is extended to the entire facility, resulting in asymmetrical large-scale damage, so-called “Progressive Collapse” under initial attack loads, minimizing local damage, and protecting the building’s integrity through isolation from other structural components. Consequently, this paper deal with physical protection system design on Unite states standards and practices for applying to physical protection system design in Republic of Korea.

Background: Low back pain is a very common musculoskeletal disorder. Since low back pain can indicate physical and psychological problems, reducing the pain level of low back pain can be the primary goal of rehabilitation. Objectives: This study was performed to explain the personalized treatment protocol of Maitland orthopedic physiotherapy based on the brick wall concept for low back pain patients with hypomobility. Design: Randomized controlled study. Methods: A total of 14 chronic low back pain patients were divided into two groups. The experimental group received orthopedic manual physical therapy intervention. The control group received traditional physical therapy intervention. After the 3 days intervention, the joint range of motion and pain of the low back were measured. Results: The low back flexion, extension, lateral flexion, and rotation joint range of motion was significantly increased in the experimental group than in the control group (P<.05). Low back pain was significantly reduced in the experimental group than in the control group (P<.05). Conclusion: It was confirmed that Maitland orthopedic physical therapy was an effective method as an intervention method to improve the joint range of motion and pain of chronic low back pain patients.

Background: Due to the COVID-19 pandemic, untact online classes have expanded in universities. To ensure continuous improvements in the quality of university education, it is important to analyze factors affecting students’ satisfaction with lectures in this untact online environment. Objectives: The aim of this study was to investigate lecture satisfaction among physical therapy students with experience of untact online classes. Design: Questionnaire design. Methods: The study population comprised 124 physical therapy students with experience of participation in untact online classes. We analyzed various factors affecting students’ satisfaction with lectures delivered via untact online classes and the correlations between these factors. Results: In terms of untact educational system quality, the level of satisfaction was significantly lower among students who had experienced more semesters with untact online classes than among those who had experienced fewer semesters with untact online classes (P＜.05). Untact educational service quality, untact educational information quality, untact educational system quality, and lecture satisfaction/recommendation intention showed statistically significant positive correlations (P＜.001). Conclusion: It is necessary to continuously improve online support systems and untact educational service quality to enhance physical therapy students’ satisfaction with lectures delivered via untact online classes.