• Title/Summary/Keyword: deterioration condition

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A Study on the Perception of Scattering Ash Facilities in Metropolitan Public Crematorium (수도권 공설화장장의 산골시설 인식에 관한 연구)

  • Nam, Yunju;Lee, Pil-Do
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.67-77
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    • 2019
  • Korea, which has changed from burial-oriented culture to cremation culture due to the increase of cremation rate, preferred charnel: however, we have adopted the new processing method of cremated remains, 'natural burial' because of deterioration of charnel facility and the problems with imposed urns. Ashes are absolutely required due to the inefficient use of territory for charnel and natural burial and natural environment pollution, but this is out of legislative system in reality. This study will hold an investigation research on ashes that handles cremated remains which is not mentioned in 'Act on Funeral Services, Etc.' as well as investigate the present-condition of 'facilities for scattering cremated ashes,' as prescribed by law. As a result, there were 42 public crematoriums with a place for scattering cremated ashes, and the name of 40 of them were hill of grave. We conducted a survey to see if the workers at public cremation facilities in the Seoul metropolitan area knew about hill of grave, 'the facilities for scattering cremated ashes.' The result showed 95.9% knew about hill of grave and 88.2% answered some improvement was partially needed. Therefore, this study is to propose improvement measures for the scattering ashes facilities of public crematoriums based on the results of research and present investigation.

The Fate of Proximal Junctional Vertebral Fractures after Long-Segment Spinal Fixation : Are There Predictable Radiologic Characteristics for Revision surgery?

  • Jang, Hyun Jun;Park, Jeong Yoon;Kuh, Sung Uk;Chin, Dong Kyu;Kim, Keun Su;Cho, Yong Eun;Hahn, Bang Sang;Kim, Kyung Hyun
    • Journal of Korean Neurosurgical Society
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    • v.64 no.3
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    • pp.437-446
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    • 2021
  • Objective : To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. Methods : A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics Results : Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017). Conclusion : Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.

A Study on the Application Method of Facility Classification System for the Development of Asset Management System for Power Generation Structures (발전구조물의 자산관리 시스템 구축을 위한 시설물분류체계 활용방안에 관한 연구)

  • Jeon, Seokhyeon;Jeong, Jeongsik;Ahn, Jinhee;Kim, Changhak
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.2
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    • pp.113-118
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    • 2019
  • Recently, the maintenance concept of infrastructure has been changed from the stability management of the structure determined by the safety inspection of the existing facilities to the asset management related to evaluating and managing the performance of the facilities. For management of the property of the facilities, it is necessary to efficiently classify their information for the maintenance and service level of the facilities and to manage them. In the case of power plant facility, especially, it is a complex structure, which is constructed in a various component and detail. In this study, therefore, the components of power plant facility were classified into facilities, spaces, parts, and elements considering the type of integrated construction classification system in Korea. To reflect the deterioration rate of the facility in accordance with environmental conditions such as airborne salt and humidity etc., it was classified by adding direction, interior, and exterior condition of each component not to be considered in the existing classification system for its effective and systematic maintenance, since it is generally located in the coastal area due to the operation of the power generation structure. The classification system developed in this study can be used as fundamental data for development of the computer system for asset management of power plant facility.

Analytical Behavior of Concrete Derailment Containment Provision(DCP) according to Train Impact Loading (열차 충돌하중에 대한 콘크리트 일탈방호시설물(DCP)의 해석적 거동 검토)

  • Yi, Na-Hyun;Kim, Ji-Hwan;Kang, Yun-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.604-613
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    • 2018
  • In recent years, numerous train derailment accidents caused by deterioration and high speed technology of railways have increased. Guardrails or barriers of railway bridges are installed to restrain and prevent the derailment of the train body level. On the other hand, it can result in a high casualties and secondary damage. Therefore, a Derailment Containment Provision (DCP) within the track at the wheel/bogie level was developed. DCP is designed for rapid installation because it reduces the impact load on the barrier and inertia force on the steep curve to minimize turnover, fall, and trespass on the other side track of the bridge. In this paper, DCP was analyzed using LS-Dyna with a parameter study as the impact loading location and interface contact condition. The contact conditions were analyzed using the Tiebreak contact simulating breakage of material properties and Perfect bond contact assuming fully attached. As a result, the Tiebreak contact behaved similarly with the actual behavior. In addition, the maximum displacement and flexural failure was generated on the interface and DCP center, respectively. The impact analysis was carried out in advance to confirm the DCP design due to the difficulties of performing the actual impact test, and it could change the DCP anchor design as the analysis results.

Quantification of Chloride Diffusivity in Steady State Condition in Concrete with Fly Ash Considering Curing and Crack Effect (재령 및 균열효과를 고려한 플라이애시 콘크리트의 정상상태 염화물 확산 특성의 정량화)

  • Yoon, Yong-Sik;Cheon, Ju-Hyun;Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.7 no.2
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    • pp.109-115
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    • 2019
  • In case of the cracks in concrete, the penetration of deterioration ions such as chloride ions in to cracks is accelerated. According to the penetration of chloride ions, structural and durability problems to RC(Reinforced Concrete) structures are caused. In this study, the accelerated chloride diffusion coefficient which is in steady state is evaluated for 2 year aged normal and high strength FA(Fly Ash) concrete, after a range of crack depths are induced up to 1.0 mm in 56 aged day. Considering crack effect by linear regression analysis, high strength concrete has slightly less increasing ratio of diffusion coefficient by crack than normal strength concrete, and diffusion coefficient increases non-linearly as crack width is increased. Also, In two types of concrete, crack effect decrease as the curing period increase. In the case of quantifying crack and curing effect by using exponential function form, the coefficients of determination are higher than those of linear regression analysis. Under steady state, it is thought that there is not a high correlation between the crack effect and the curing effect, and considering the two independent effects, it is believed that reasonable prediction equation for diffusion of concrete with crack can be proposed.

An Experimental Study on the Evaluation of EMP Shielding Performance of Concrete Applied with ATMSM Using Zn-Al Alloy Wire (Zn-Al 합금 선재를 이용한 금속용사 공법 적용 콘크리트의 전자파 차폐 성능 평가에 관한 실험적 연구)

  • Choi, Hyun-Jun;Park, Jin-Ho;Min, Tae-Beom;Jang, Hyun-O;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.3
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    • pp.209-217
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    • 2019
  • EMP (Electromagnetic Pulse) usually means High Power Electromagnetic Wave (HPEM). In the case of the shielding plate against the EMP, there is a possibility of deterioration of the electromagnetic wave shielding performance due to the skill of the constructor, bad construction, deformation of the shielding plate at the connection portion (joint portion). The inefficient use of space due to the separation distance is also pointed out as a problem. Therefore, this study aims to derive the optimum electromagnetic shielding condition by applying ATMSM to concrete as a part of securing electromagnetic wave shielding performance with reflection loss against concrete wall. Experimental parameters included concrete wall thickness and application of Zn-Al ATMSM. For the concrete wall, the wall thickness was 100 to 300mm, which is generally applied, and experimental parameters were set for the application of Zn-Al metal spraying method to evaluate electromagnetic shielding performance. Experimental results showed that as the thickness increases, the electromagnetic shielding performance increases due to the increase of absorption loss. In addition, after the application of Zn-Al ATMSM, the average shielding performance increased by 56.68 dB on average, which is considered to be increased by the reflection loss of the ATMSM. In addition, it is considered that the shielding performance will be better than that when the conductive mixed material and the ATMSM are simultaneously applied.

Early Frost Damage and Diagnose of Damage Depth Due to Early Frost Damage of the Concrete According to the Thickness of Members (부재 두께 변화에 따른 콘크리트의 초기동해 특성 분석 및 깊이진단)

  • Kim, Tae-Woo;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.2
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    • pp.131-138
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    • 2019
  • Recently, there are many structures exposed to severe outdoor environments, which results in rapid degradation of durability of the concrete structures. there can be rapid deterioration of the concrete structures from early frost damage due to the insufficient curing in low outdoor temperature condition. The objective of this study is to investigate the effect of thickness change conditions and binding material on early frost damage depth of the concrete exposed to cold weather in winter, and is to clearly assess damage depth of the concrete structure due to early frost damage. Specimens with 300x300x(150, 200, 250, 300mm) were prepared. OPC and OPC+FA+BS were adopted for binders. Test results indicate that the depth of the early frost damage was deeper with the decrease of thickness of members. The brightness of specimens were reduced when the member thickness was thinner. When determining the depth of early frost damage, it can be distinguished into dark color and relatively bright color when dried for approximately 30 minutes in the indoors of $20^{\circ}C$ in temperature and 60% in relative humidity after submerging in water for 24 hours. The dark colored part can be determined easily when measured with vernier calipers.

A Study on Applicability of Neem Resin as a Fixative on the Painting Layer of Mural Paintings from Payathonzu Temple in Bagan, Myanmar (미얀마 바간유적 파야톤주 사원벽화의 채색층 고착처리를 위한 님(Neem) 수지 적용 가능성 연구)

  • Eum, Sojeong;Lee, Hwasoo
    • Conservation Science in Museum
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    • v.24
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    • pp.117-132
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    • 2020
  • The painting layer of Payathonzu temple mural paintings in the ruins of Bagan Myanmar has been damaged due to various reasons. In this study, the applicability of Neem resin, a traditional Myanmar adhesive, as a fixative on the painting layer was examined. Cow glue and Paraloid B-72 were selected as fixatives in the comparison group, and pseudo-specimens with conditions similar to the original mural paintings were produced to examine the changes before and after applying the fixatives and according to the deterioration experiments. As a result of conducting the experiments and comparing the fixatives, it was found that changes on the surface such as smudge, yellowing and gloss are greater with the application of higher concentration of Neem resin than with other fixatives. However, such changes were relatively small under the condition of 4% concentration. It was also confirmed that chromaticity and glossiness vary greatly between before- and after-application of the fixatives but that such discrepancies tend to decrease at 4% concentration compared to other concentrations. As for fixation strength, it was found that the fixation capacity of Neem resin on the base and painting layers is overall higher than other fixatives as the concentration is increased. Therefore, the applicability of 4% concentration of Neem resin as a fixative on the painting layer was confirmed considering the low surface changes according to environmental factors, low color discrepancy and glossiness, and characteristics of excellent fixation strength. It is believed that the findings of this study could be used as basic data for the preservation of Payathonzu temple mural paintings in the future.

Effect of Hominis Placenta Pharmacopuncture for a Patient with Mild Cognitive Impairment: A Randomized, Double-Blind, Placebo-Controlled, Multi-Center Trial

  • Kim, Yunna;Eom, Yoon Ji;Kwon, Dohyung;Lee, Jae Hyok;Jung, In Chul;Cho, Eun;Lee, Ji Eun;Cho, Seung-Hun
    • Journal of Oriental Neuropsychiatry
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    • v.32 no.2
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    • pp.81-93
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    • 2021
  • Objectives: Mild cognitive impairment (MCI) is condition of cognitive decline shown in transition from normal aging to dementia. Hominis placenta pharmacopuncture (HPP) is a treatment that combines effects of medication and acupuncture by injecting Hominis placenta into acupoints. The objective of this study was to evaluate the efficacy and safety of HPP for MCI. Methods: This was a randomized, double-blind, placebo-controlled, two-center clinical trial. Eligible patients were randomly allocated to either the HPP group or the placebo group. HPP or saline as placebo was administered to participants for eight weeks. Changes in symptoms were observed. The primary outcome was difference in mean change of Korean Version of the Montreal Cognitive Assessment (MoCA-K) score between the HPP group and the placebo group. Cognitive function, overall status of mood and sleep, and quality of life (QoL) were also assessed. Safety assessment and economic analysis were then conducted. Results: Thirty participants were enrolled. One participant in the placebo group dropped out. The score of MoCA-K increased after treatment. Its mean change was smaller in the HPP group than in the control group. HPP ameliorated Global Deterioration Scale and Korean Dementia Rating Scale subtests for attention, organization, and memory compared to the placebo. However, none of them was significantly different between the two groups. Mood, sleep, and QoL all improved more in the HPP group than in the placebo group, although differences between the two groups were not statistically significant. There was no adverse event probably related to the drug. HPP treatment needed KRW 345,000 more than the placebo group in improving Geriatric Quality of Life scale-Dementia score by one point for one year. Conclusions: Although HPP treatment did not significantly improve cognition, it changed behavioral and psychological symptoms in MCI.

Properties on the Airborne Chlorides of Offshore Bridges on the Western/Southern Coast in South Korea (국내 서/남해안 해상교량의 월별, 높이별 비래염분량 특성)

  • Jung, Jahe;Min, Jiyoung;Lee, Binna;Lee, Jong-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.2
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    • pp.59-67
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    • 2022
  • In this study, the monthly airborne chlorides flying into the offshore bridges were investigated depending on the sea level. The target structures were 9 bridges located on the western and southern coast of South Korea. The airborne chlorides were measured at different sea levels on each bridge every month during 1 year. The results showed that the strongest seasonal wind from the northwest in winter expecially have led increase of the airborne chlorides, and its effect was more significant in the western coast than the southern coast. It was also found that the airborne chlorides declined with the increase of sea level. Three types of curves were suggested for analyzing the decrease trend with the sea level, based on the airborne chlorides at the lowest measurement height of main tower. The trend was varied depending on the sea area, and even in the same sea area, the local topographic condition affected the airborne chlorides. It means that the location and local topography should be considered simultaneously for durability management in the framework of the chloride source, and then the influence of the chloride source should be classified, e.g. safe and dangerous. From these results, it is expected that it could be used as baseline data for the evaluation of the deterioration environment in the Detailed guidelines for safety and maintenance of facilities [Performance evaluation]_Bridge.