Background: Previous studies have reported that improving the spinal stability could be more effective in the prevention and treatment of recurrence. Lumbar stabilization exercise is known to strengthen the lumbar extension muscles and enhance physical, psychological and social functions. Objectives: To investigated the effect of lumbar spiral stenosis on the kinetic link training and lumbar stabilization exercise. Design: A randomized controlled trial. Methods: Study was preformed by randomly allocated 28 LSS participants into a kinetic link training group (KLT, n=14) and a lumbar stabilization exercise group (LSE, n=14). Kinetic link training and lumbar stabilization exercise were performed to subjects in both groups 5 times a week for 6 weeks. To verify the effect of LSS, changes in VAS, ODI, and proprioception before and after intervention were observed. Results: In KLT, statistically significant changes were found in VAS, ODI, and Proprioception before and after intervention. In LSE, there were significant changes in VAS and ODI before and after intervention. KLT and LSE before and after intervention indicated significant differences in proprioception. Conclusion: KLT and LSE are applied to LSS, there are effects of pain decrease, lumbar recovery and proprioception improvement.

Background: Generally, rounded shoulders may occur when an individual habitually takes a relaxed, slouched posture. Although various studies on the round shoulder exist, studies on the effect of improvement of thoracic mobilization on the round shoulder are insufficient. Objectives: To investigate the effect of thoracic mobilization on round shoulders and pulmonary capacities. Design: Randomized controlled trials. Methods: Twenty subjects were randomly allocated into an exercise group (n=10) and a mobilization group (n=10). To quantify the round shoulder before and after the intervention, the distance between the acromion and the table surface was measured, and the pulmonary capacities were also measured. The intervention program was conducted twice a week for 6 weeks. The exercise group performed corrective exercise, and the mobilization group performed both corrective exercise and thoracic mobilization. Results: The round shoulder in both groups was significantly decreased (P<.05), and the pulmonary capacities were significantly improved (P<.05). However, there was no significant difference between the two groups (P>.05). Conclusion: The combination of corrective exercise with stretching and strengthening exercises led to the improvement of round shoulders and pulmonary capacities, no additional benefits were detected with thoracic mobilization.

Background: Women patients who have undergone high tibial osteotomy need management to control walking and balance and to enable functional daily life. In that way, land-based physical therapy and aquatic physical therapy were performed. Objectives: To investigated the effect of land-based and aquatic physical therapy on the balance and walking of women who had undergone high tibial osteotomy. Design: Randomized control trial. Methods: In all, this randomized controlled trial enrolled 21 patients with high tibial osteotomy who received land-based physical therapy (LP, n=7), aquatic physical therapy (AP, n=7), and land-based and aquatic physical therapy (LAP, n=7). Single-leg standing balance, 10-m walk test, and Knee injury and Osteoarthritis Outcome (KOOS-12) scores were. The intervention period was 3 days per week for 6 weeks. Results: One-leg standing balance and 10-m walk test increased statistically, and KOOS-12 score also increased statistically. All three groups have improved. As a result, the variable changes were compared in three groups, and although there was no significant difference between the land-based and aquatic physical therapy groups, the land-based and aquatic physical therapy combined programs improved further than the previous two groups. Conclusion: The balance and walking of female patients with high tibial osteotomy were found to have been very effective in land physical therapy and aquatic physical therapy. In addition, the land-based and aquatic physical therapy combination program can improve balance and walking more effectively.

Background: The purpose of this study was to investigate whether the function of stroke patients could be improved by simultaneously performing bridging and masticating exercises. And, this was tested by examining whether the effects of arousal and cognitive improvement due to mastication muscle activity could affect exercise ability. Objectives: To compare the effects, the movement of the center of pressure and the stability limit change were measured using a balance analysis platform (BT4). Design: Randomized controlled trial. Methods: In this study, 36 chronic stroke patients were randomly assigned to either single training group of the bridging exercise or combined training group that performed both the bridging exercise and the mastication exercise. The exercise was performed for thirty minutes a day, three times a week, for eight weeks. Results: In both groups, the static balance ability improved after exercise, but the dual-task training group had a better improving effect on the distance and area of the center of pressure while the eyes was open. The dynamic balance ability also improved after exercise, and the dual-task training was more effective in reducing forward, left, and right movements, but not in backward movement. Conclusion: The importance of mastication was recognized in the rehabilitation of chronic stroke patients, and it can be expected to use mastication to improve balance in stroke patients in the future.

Background: The rounded shoulder posture (RSP) causes the protraction, downward rotation, and anterior tilt of the scapula. Many studies reported that various interventions for the RSP could be helpful for RSP correction. However, no study has reported on the effect of an orthosis on the RSP. Objectives: To investigate the effect of an orthosis on the RSP in comparison with kinesio taping in 32 participants with RSP. Design: Quasi-experimental study. Methods: Thirty-two participants with RSP were randomly assigned into the kinesio taping group (n=15) and orthosis group (n=17). Kinesio taping was applied as follows: 1) both sides of the spine in a vertical direction from C7 to T12. 2) Both sides of the spine in an oblique direction from the coracoid process of the scapula through the acromion to the T12. Orthosis was tried on, and a pull adjustment strap was used to correct the RSP for each participant. Results: Both groups showed significant differences in the height of the acromion to the ground, forward head angle, forward shoulder angle, visual analog scale, and neck disability index within each group. However, no significant differences in all measurements were observed between the two groups. Conclusion: Orthosis for the RSP with exercise would improve the correction of the RSP as much as kinesio taping.

Background: Scoliosis can be caused by postural changes. The effects of Schroth exercises and Kinesio taping for scoliosis have been reported independently, but there are few studies on the effects of combining both methods. Objectives: To investigated the effects of Schroth exercises and kinesio taping on the Cobb angle and dynamic balance ability in patients with scoliosis. Design: Quaxi-experimental study. Methods: Participants were divided into the taping (n=3) and non-taping (n=3) groups. Pre-tests for the Cobb angle and dynamic balance were performed prior to the first intervention, and post-tests were performed after the intervention was completed. The non-taping group performed Schroth exercises for a total of 12 35-minute sessions thrice a week for 6 weeks. Meanwhile, in the taping group, Kinesio tape was attached before performing the same exercises and was maintained for 24 hours after the exercises were finished. Results: In the taping group, there was no significant change in the Cobb angle and dynamic balance ability pre- and post-intervention (P>.05). Similarly, there was no significant change in the Cobb angle and dynamic balance ability pre- and post-intervention (P>.05) in the non-taping group. Furthermore, there was no significant difference upon comparing the two groups (P>.05). Conclusion: Kinesio taping combined with Schroth exercises did not give additional benefits in terms of the Cobb angle and dynamic balance ability than that in the application of Schorth exercises alone.

Background: The traditional treatment protocol in adhesive capsulitis cases is physical therapy agents and a home exercise program. The extensive majority of patients respond to conservative treatment, but the painful rehabilitation program makes it inconvenient for individuals to fully comply with the treatment. In order to reduce pain and spasm, intraarticular injections or suprascapular nerve block may be effective before the rehabilitation program. Objectives: To investigated the effect of suprascapular nerve block (SNB), which is added to standard physical therapy on pain, functionality and range of motion in patients with adhesive capsulitis (AC). Design: Retrospective study. Methods: This study included 46 patients who were treated for AC. Patients in both groups were given 15 season physical therapy and home exercise. The treatment group consisted of patients who underwent multiple SNB in addition to physical therapy and home exercise. Datas were analyzed retrospectively. Results: The Visual Analogue Scale (VAS), ROM, Shoulder Pain and Disability Index (SPADI) and Constant scores in both groups after treatment and at the third month follow-up (P<.001). In the comparison between the groups, it was determined that the improvement in VAS, ROM and SPADI scores in the treatment group at the 3-month control was statistically significant (P<.05). Conclusion: Multiple SNB added to physical therapy and home exercise program in cases of AC may be effective in terms of pain control, increasing joint range of motion and improving functionality.

Background: Although several studies have reported functional improvements after forward walking training on a treadmill and after backward walking training on a treadmill, there is a lack of immediate effects data, investigating spatiotemporal parameter, neuromuscular recruitment. Objectives: To compare the immediate effects between forward and backward walking on treadmill training, present study measured muscle activities of the lower extremity, gait parameters, and dynamic balance. Design: Cross-sectional study. Methods: The twenty-four asymptomatic young male subjects were participated in this study. Subjects have performed 15-min of forward and backward walking on treadmill. Before and after treadmill walking, the gait parameters were measured with the GAITRite. The dynamic balance abilities were assessed with the Y-balance test. Muscular activities were collected from the tibialis anterior, gastrocnemius, biceps femoris, and rectus femoris during forward and backward walking. Results: Muscular activities of the biceps femoris and tibialis anterior were significantly different between forward and backward walking conditions, which were higher with the backward walking (P<.05). Compared to the pre-measurement, the normalized dynamic balance composite score of the post-measurement was significantly higher with the backward walking (P<.05). Regardless of the treadmill training method, there were no significant differences between pre and post measurement, both the stride length and step length (P>.05). Conclusion: The performing backward walking training has positive effects for dynamic balance.

Metal halide perovskite (MHP) nanocrystals (NCs) have emerged as promising materials for various optoelectronic applications including photovoltaics, light-emitting devices, and photodetectors because of their high absorption coefficient, high diffusion length, and photoluminescence quantum yield. However, understanding the morphological evolution of the MHP NCs as well as their controlled assembly into optoelectronic devices is still challenging and will require further investigation of the colloidal chemistry. In this study, we found that the amount of n-octylamine (the capping agent) plays a crucial role in inducing further growth of the MHP NCs into one-dimensional nanowires during the aging process. In addition, we demonstrate that the dielectrophoresis process can permit self-alignment of the MHP nanowires with uniform distribution and orientation on interdigitated electrodes. A strong light-matter interaction in the MHP NWs array was observed under UV illumination, indicating the photo-induced activation of their luminescence and electrical current in the self-aligned MHP nanowire arrays.

This study explored the possibility of forming a coating layer containing alginic acid on the surface of a magnesium alloy to be used as a biomaterial. We formed a coating layer on the surface of a magnesium alloy using a plasma electrolytic oxidation process in an electrolytic solution with different amounts of alginic acid (0 g/L ~ 8 g/L). The surface morphology of all samples was observed, and craters and nodules typical of the PEO process were formed. The cross-sectional shape of the samples confirmed that the thickness of the coating layer became thicker as the alginic acid concentration increased. It was confirmed that the thickness and hardness of the sample significantly increase with increasing alginic acid concentration. The porosity of the surface and cross section tended to decrease as the alginic acid concentration increased. The XRD patterns of all samples revealed the formation of MgO, Mg2SiO4, and MgF2 complex phases. Polarization tests were conducted in a Stimulate Body Fluid solution similar to the body's plasma. We found that a high amount of alginic acid concentration in the electrolyte improved the degree of corrosion resistance of the coating layer.

This study investigated a graded-refractive-index (GRIN) coating pattern capable of improving the light extraction efficiency of GaN light-emitting diodes (LEDs). The planar LEDs had total internal reflection thanks to the large difference in refractive index between the LED semiconductor and the surrounding medium (air). The main goal of this paper was to reduce the trapped light inside the LED by controlling the refractive index using various compositions of (TiO2)x(SiO2)1−x in GRIN LEDs consisting of five dielectric layers. Several types of multilayer LEDs were simulated and it was determined the transmittance value of the LEDs with many layers was greater than the LEDs with less layers. Then, the specific ranges of incident angles of the individual layers which depend on the refractive index were evaluated. According to theoretical calculations, the light extraction efficiency (LEE) of the five-layer GRIN is 25.29 %, 28.54 % and 30.22 %, respectively. Consequently, the five-layer GRIN LEDs patterned enhancement outcome LEE over the reference planar LEDs. The results suggest the increased light extraction efficiency is related to the loss of Fresnel transmission and the release of the light mode trapped inside the LED chip by the graded-refractive-index.

Magnesium-antimonide is a well-known zintl phase thermoelectric material with low band gap energy, earthabundance and characteristic electron-crystal phonon-glass properties. The nominal composition Mg3.8-xZnxSb2 (0.00 ≤ x ≤ 0.02) was synthesized by controlled melting and subsequent vacuum hot pressing method. To investigate phase development and surface morphology during the process, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out. It should be noted that an additional 16 at. % Mg must be added to the system to compensate for Mg loss during the melting process. This study evaluated the thermoelectric properties of the material in terms of Seebeck coefficient, electrical conductivity and thermal conductivity from the low to high temperature regime. The results demonstrated that substituting Zn at Mg sites increased electrical conductivity without significantly affecting the Seebeck coefficient. The maximal dimensionless figure of merit achieved was 0.30 for x = 0.01 at 855 K which is 30% greater than the intrinsic value. Electronic flow properties were also evaluated and discussed to explain the carrier transport mechanism involved in the thermoelectric properties of this alloy system.

최근 발생하는 테러공격들 중 4차 산업혁명을 통해 새롭게 떠오르는 신 흥기술인 드론, 3D 프린팅 건, 인공지능 등을 이용한 테러공격과 사이버 테러가 증가하면서 이로 인한 테러공격의 충격과 공포의 파급효과가 더 크게 나타나고 있다. 문제는 이러한 기술이 비싸지 않고 쉽게 구입할 수 있는 일상적인 도구들이어서 악의적인 의도를 가진 일반인들과 극단주의 자들, 그리고 테러리스트들이 쉽게 테러이용수단으로 활용할 수 있다는 점이다. 더 우려스러운 점은 이 같은 신흥기술을 이용한 테러이용수단들 은 폭탄, 총포류 등의 전통적인 테러이용수단을 사용한 테러에 대한 대응 방안을 갖추고 있는 현재의 중요기반시설들과 다중이용시설 등의 보안을 위한 테러 대응전략과 방안들을 무력화시킨다는 것이다. 신흥기술을 이용 한 테러위협에 대한 대응은 특히 과학적 측면에서 연구되고 개발되어야 할 부분이기 때문에 이러한 위협에 대한 실효적인 테러대응방안을 수립하 려면 테러대응기관들과 안보기관들, 관련 신흥기술의 전문가들로부터 과 학적 연구, 실험, 개발 등의 지원을 받아야만 한다. 그러나 국내의 경우는 아직까지 신흥기술을 이용한 테러 공격에 대한 적절한 테러 방어기술이나 전략이 미흡하다. 이런 문제의 근본 이유는 국내의 주요 테러대응기관이 나 안보관련 기관들이 신흥기술에 대한 대비를 할 수 있도록 지원하는 과 학과 증거에 기반 한 연구, 실험, 그리고 개발을 위한 체계·권한·예산·인 력 등이 현재의 국내 법률상의 한계로 인해 제대로 구축되거나, 지원되거 나, 혹은 운용되지 못하기 때문이다. 이에 따라 이 연구는 신흥기술을 이용한 테러공격에 대비하고 있는 선 도적인 모범사례에 해당하는 미국 국토안보부(DHS)의 Science and Technology Decorate(S&T)와 Emerging Technologies Subcommittee of the Homeland Security Advisory Council (이하 HSAC)의 활동, 역할, 임무를 소개한다. 미국의 S&T는 현존하는 그리고 3년에서 10년의 단기, 그리고 더 먼 미래에 신흥기술을 포함한 모든 부분에서 미국 국가 의 안보를 헤치고 국민의 생명과 재산 그리고 민주주의의 절차에 도전이 되는 다양한 위협들을 파악하고 이에 대한 대응방안을 각 분야의 최고 전문가와 전문연구센터들과 함께 연구하고 있다. 이와 함께, 이 연구는 이러한 S&T의 활동을 가능하게 하는 관련 법령인 신흥위협예방법 2018 (The Preventing Emerging Threats Act of 2018)(S.2836)에 대해 소 개한다. 그리고 마지막으로 이 연구에서 소개하는 미국 사례에 대한 정책 적ㆍ법적 시사점과 국내의 적용가능성에 대해 논의하였다.

UN 출범 이후 80년이 되어가는 2022년의 시점에도 추축국으로 표상 되는 독일 및 일본과 관련된 우리의 역사적, 정치적 인식에는 극명한 차 이 및 대비가 존재한다. 즉, 독일의 경우 전후처리 문제에 있어 일본과 대조되는 진정한 반성 및 후속 대처의 모범적 사례로서 우리 사회에 긍정 적으로 다가옴은 주지의 사실이다. 이는 일단, 조선 말기 이래 유무형의 막대한 피해를 일제로부터 경험하였음에 기인한다. 그리고 해방 및 대한 민국 정부 수립 이후 지금까지 국제법상 식민지 청산 문제가 계속되는 현 실 속에서 인권 담론과 유리된 일본의 자세가 대한민국 각계의 분노를 촉 발하였으며, 그와 대비되는 실행을 모색하도록 촉발한 측면이 존재한다. 하지만 거듭 소환되는 독일의 ‘사례는 침략 및 과거사에 대한 전향적 반성 및 대처의 모범이 될 만한지, 과연 보편적이고 명백한 실행인지 점 검할 필요가 있다. 체코 및 근년의 나미비아에 대한 실행을 보면 독일은 역사적 과오나 국제법상 국가책임 자체는 인정하되, 구체적 배상문제와 관련하여서는 피해자 측에 대한 양비론적 비판이나 국내외법상 근거를 엄 격히 요구하는 경향이 있으며, 관습 국제법이나 지엽적 절차법의 문제를 들어 제소를 방해하거나 배상(reparation)의 형식에 반대하기도 한다. 다 만, 나미비아 피해자 유족들은 최근 독일에 대한 미국내 주권면제 관련 소송에서 패소하였으나 이 패소는 헛된 것이 아니며, 오히려 구독일 제국 의 나미비아 헤레로족 및 나마족 학살 사건의 청산 문제 해결을 촉발하기 도 하였다. 또, 독일의 승소는 역설적으로 역사적 가해국의 배상문제에 관한 소극성, 양면성을 보여주는 계기로 작용한다는 점에서 중-동부 유럽 에서의 독일의 수정주의적 시각과도 접점이 존재한다. 우리로서는 향후 잠재적인 사안에 있어서 일본에 대항하는 주권면제 부 인론 등의 논리를 어떻게 확보할 것인가? 설사, 패소한 사안에 대해서도 전투에서 지고 전쟁에서 이기는 효과로 전환 시킬 여지는 없는가? 이런 부분에 대한 고민이 필요함을 언급하면서, 이번 연구에서의 문제 제기에 갈음하고자 한다.

In this study, a two-stage electrostatic precipitator (ESP) was developed using a novel automatic dry cleaning device to reduce the ultrafine particles in subway stations. Collection efficiency was evaluated with a pilot scale ESP (1.2m× 1.2m) and the scale of the test duct was half of the subway air handling unit. The maximum collection efficiency for 0.3 μm particles was 96.9%. In addition, we studied a method of automatic dry cleaning for maintenance of the ESP. The cleaning efficiency was analyzed according to the cleaning flow rate for each particle loading amount to achieve a recovery rate over 90%. In addition, we derived the equation to estimate the reduction in collection efficiency according to the particle loading amount. It was confirmed that the performance of the contaminated ESP was restored to the initial state by the automatic dry cleaning in this study and that the electrical energy consumption was 5 times lower compared to utilizing conventional water cleaning.

환경개선에 대한 국제법적인 의무가 우리 정부에도 부과되어 있는데, 환경개선에 대한 한계의 원인과 진상을 규명하면서 이에 대한 효과적인 수단으로서 인공지능기술 등 4차산업혁명기술을 활용하는 것의 가능성과 효과성에 대하여 그동안 미진하였던 새로운 기초연구를 진행하였다. 그동 안 입법정책에 대한 기초적인 연구를 하는 것은 환경법분야에서도 쉽지 않았고 미진한 점들이 많았다. 입법정책에 대한 기초적인 연구를 통하여 앞으로 전개될 세부적이고 구체적인 환경법정책에 분석적이며 조화로운 나침반을 제공해 줄 실익이 있을 것으로 기대한다. 인공지능 등 4차산업혁명기술이 사회를 변화시켜가고 있다. 이는 인류가 그동안 환경개선을 위한 노력이 효과를 크게 보지 못한 한계를 극복하는 데 새로운 희망을 줄 수 있을 것이라는 새로운 학문과 정책상의 관점이 최근에 전 세계적으로 제기되고 있다. 인류는 기후변화에 대응하기 위하여 유엔기후변화협약(United Nations Framework Convention on Climate Change), 교토의정서(Kyoto Protocol) 등은 물론이고 최근의 파리협정 (Paris Agreement) 등 국제적인 노력을 많이 기울여 왔다. 그러나 환경 정책을 강화하는 것은 화석연료를 사용한 경제개발에 역행하는 것이라는 모순된 전제를 극복할 수 없었기에 우리 정부는 선뜻 국제법적인 환경정 책을 본격적으로 실시하지 못하였다. 또한 부족한 인간의 힘으로 일일이 기후변화의 원인들을 24시간 모니터링하고 장소에 구애받지 않는 분석과 조치를 취하기에는 한계가 많았다. 본 연구에서는 환경개선의 새로운 패러 다임으로서 인공지능 등 4차산업혁명기술과 환경을 연결하는 학제간의 융 합법적인 기초작업을 그린뉴딜정책을 위하여 진행하고자 한다. 이를 위하여 첫 번째, 그린뉴딜이 4차산업혁명기술과 환경정책을 연결 하고 접목할 수 있는 가능성과 허용성이 있음을 확인하였다. 두 번째, 그린뉴딜이 기존의 환경정책들의 단순한 집합이나 나열에 지나지 않고, 새로운 내용과 성질의 진테제로서의 환경법 정책으로 평가할 수 있음을 유럽과 미국 등의 그린딜을 비교하면서 확인하였다. 세 번째, 그린뉴딜이 4차산업혁명기술과 기존의 환경법정책을 결합하여 새로운 진테제로서의 법정책적 내용으로서 그린뉴딜이라는 목표가 분명하게 드러날 수 있도록 법령의 목적을 조정하고 수정하는 작업이 필요함을 개별법을 통해 고찰하 였다. 네 번째, 특히 한국의 그린뉴딜이 실패하지 않고 기존의 환경정책 과 달리 의도한 성과를 확보하고 공정하고 정의로운 사회로 이행할 수 있 기 위해서는 다양한 기존의 법령에 그린뉴딜의 정책을 반영한 입법정책적 인 제언을 함으로써 법정책적인 함의를 밝혔다. 이는 한국형 그린뉴딜에 대한 입법적 과제와 입법 현황 평가를 다양한 분야들에 걸쳐서 실시해 본 결론이다. 구체적으로는 탄소감축에 대한 직접적인 감축을 위한 대응성 과제, 탄소감축을 위해 생산과 소비 및 에너지의 구조변화를 위한 적응성 과제, 4차산업혁명을 통한 기후변화정책에의 직업과 참여 확대, 한국형 그린뉴딜에서 장애조항들의 제거 및 규제완화, 4차산업혁명기술을 통한 기후변화정책이 가능하도록 교육의 확대 강화, 4차산업혁명을 통한 기후 변화정책에의 성과의 배분과 포용 등의 분야들이다. 결론적으로 한국형 그린뉴딜에 대한 제언으로서 한국형 그린뉴딜의 목 적 규정 수정과 교육목표ㆍ원칙 추가, 한국형 그린뉴딜을 촉진할 대응성 규정의 마련과 보완, 한국형 그린뉴딜을 촉진할 적응성 규정의 마련과 보 완, 한국형 그린뉴딜에서 정의로운 대전환을 위한 구체적 입법의 마련 등 이 요구된다.

Although airborne wear particles (AWPs) generated from wheel-rail contacts are the major source of particulate matter (PM) in subway systems, studies on reducing the generation of such particles in order to enhance air quality are extremely rare. Therefore, this study investigated the effect of applying water-lubricant (applying tap water) on improving air quality by reducing the mass concentration (MC) of AWPs from wheel-rail contacts at a train velocity of 73 km/h using a twin-disk rig. An optical particle sizer was used to measure the MC of particles with the diameter range of 0.3 μm~10 μm. The results showed that the generation trends regarding PM1, PM2.5, and PM10 were different for dry and water-lubricated conditions: all three PMs showed an increasing-decreasing trend with slip rate under dry conditions; however, they were almost constant with slip rate under water-lubricated conditions. The particle size distributions were also different for dry and water-lubricated conditions: the peak occurred in multi-modal with the largest peak at approximately 6 μm in diameter under dry conditions; whereas, the peak occurred in bi-modal with the largest peak at approximately 0.9 μm in diameter under water-lubricated conditions. In addition, MCs were mostly smaller under water-lubricated conditions than dry conditions except at approximately 0.9 μm in diameter. Applying water significantly decreased PM1~2.5 and PM2.5~10 by more than 95%. This caused a decrease in PM2.5 and PM10 by 48.1% and 78.5%, respectively. On the other hand, applying water increased PM0.3~1 (i.e., PM1) by 52.8%, possibly owing to the effect of water vapor and mineral crystals from tap water. Overall, these findings indicate that water-lubrication can improve air quality in subway systems by reducing the MC of APWs generated from wheel-rail contacts. This study may provide a reference for future studies seeking to improve air quality in subway systems by reducing AWPs generated from wheel-rail contacts by applying lubricants.

This study installed and evaluated the efficiency of a radon barrier membrane, radon mat, and radon well in the removal and reduction of radon gas that originates from the soil and flows indoors. The study aims to present a fundamental and long-term solution to radon reduction in buildings by preventing soil radon, which is the main source of radon gas, from migrating indoors. A radon barrier membrane, radon mat, and radon well were developed and verified, and the radon reduction effect of each system was evaluated. Through applying a special radon gas blocking film with a 5-layer structure, the radon barrier membrane prevents radon gas particles from passing through the polymer deposited on the radon blocking film. The radon mat is a type of radon reduction construction method that induces radon gas generated from the soil under the building to move in the desired direction through the plate-structured pressure reducing panel and discharges radon gas to the outside of the building through an exhaust pipe and fan installed at the edge. In addition, the radon well can also be applied to special structures such as old buildings and historical sites where it is difficult to directly reduce radon concentration within the building foundation, because the intake area can be controlled and, therefore, the method can be applied in a variety of environments and ranges. In the case of Intervention 1 (installing a radon barrier membrane and radon mat), the soil radon was reduced by 24.7%. Intervention 2 (installing a radon barrier membrane, radon mat, and radon well) reduced the soil radon by 45.1%, indicating that the effect of reducing the soil radon concentration was 1.8 times higher compared with installing only the radon barrier membrane and radon mat. The measurement showed that the indoor radon concentration was reduced by 46.5%, following the reduction in soil radon concentration through Interventions 1 and 2, demonstrating the effect of reducing indoor radon gas by installing the radon barrier membrane, radon mat, and radon well. Through the production and installation of prototype systems, this study confirmed the reduction effect of radon concentration in soil and indoor air. These systems achieved a higher efficiency at a relatively low cost than that achieved with the existing radon reduction methods applied in Korea and abroad.

Volatile organic compounds (VOCs) emitted from industrial gas cause equipment failure and fire accidents due to the rapid flow and concentration changes of VOCs. Therefore, it is crucial to attenuate the concentration of VOCs to ensure a constant emission rate before the control process. This study proposed an encapsulation technique to fabricate calcium- alginate gel beads containing paraffin oil as an effective absorbent. The prepared absorbent was physically characterized, and a column test observed its absorption capacity. When the oil content was 30%, the prepared beads showed the best spherical shape, attaining 96% emulsion stability, 0.014 sphericity factor, 62.7% weight variation ratio, and 4.21 ± 0.06mm diameter. In the column test that was packed with the prepared beads, the toluene absorption capacity was 497.6mg/kg. The net effect of the beads was to attenuate the peaks of toluene concentration, and to make the VOC-laden air stream more receptive for the subsequent treatment unit.

A field study was conducted to reduce airborne bacteria by supplying active ions to indoor spaces used by vulnerable human groups spending substantial amounts of time in places such as schools and hospitals. In an experiment conducted during school hours (8:00-15:00), the average number of airborne bacteria in classrooms was 345.53 CFU/m3 or more without active ions. However, ion supply reduced the airborne bacteria to an average of 113.23 CFU/m3, indicating an efficiency of 61.61%. As a result of tests in 33 rooms used for surgery in small and middle sized hospitals, ion supply for 2 to 4 hours reduced the average airborne bacteria concentration from 243.88 CFU/m3 to 104.34 CFU/m3, representing a 41.53% reduction. A laboratory test to confirm the ion activity has shown that the mortality rate of E. coli used as a test bacterium increased with exposure time to ions. The initial colony number of E. coli was 251 CFU, but decreased to 4 CFU after 60 minutes of exposure to active ions. Therefore, it was confirmed that the supply of active ions can contribute to the control of airborne bacteria in the indoor environment of schools, hospitals and other public facilities.