• Title/Summary/Keyword: STABILITY

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Prediction of Damages and Evacuation Strategies for Gas Leaks from Chlorine Transport Vehicles (염소 운송차량 가스누출시 피해예측 및 대피방안)

  • Yang, Yong-Ho;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.407-417
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    • 2024
  • The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

Symptoms of the subject in a movie based on Lacan's work on psychosis - Focusing On Lars von Trier's film (라캉의 정신병 연구에 근거한 영화 속 주체의 증상 - 라스 폰 트리에의 <살인마 잭의 집>을 중심으로)

  • HAN JINGZHI
    • Trans-
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    • v.16
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    • pp.69-105
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    • 2024
  • The House that Jack Built (2018), a film about how the protagonist Jack is reborn as a "mad artist" with psychotic symptoms during a 12-year killing spree, provides an interesting opportunity to analyze the film in terms of psychoanalysis and religion. Jack, an engineer who suffers from OCD, finds pleasure in the accidental murder of a character and considers killing people as an art form, overcoming his OCD in the process. The question we are interested in is whether the symptoms of OCD are truly overcome by the act of repeated killing. The idea is that Jack's OCD is not overcome by killing, but rather that the symptoms disappear as he moves from neurosis to a stabilized psychotic state. According to the theory of the famous French psychoanalyst Lacan, the hallucinations or delusions that human subjects experience when they lose their realistic stability are a phenomenon that occurs when they are confronted with The Real, which penetrates through the cracks of the symbolic system. Phenomena such as Jack's illusory reality and delusions in the movie are pathological symptoms of the absence of a paternal figure in his life, causing the Name-of-the-Father to fail to take hold. This paper deciphers the psychotic structure of Jack, the protagonist of Lars von Trier's House of Jack, through Lacanian psychoanalysis.

Biodegradation effect of cross-cultivated fungi and edible mushrooms on plastic films (식용버섯과 진균 교차 배양을 활용한 플라스틱 필름의 생물학적 분해효과)

  • Doo-Ho Choi;Eunji Lee;Gi-Hong An;Kang-Hyo Lee
    • Journal of Mushroom
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    • v.22 no.1
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    • pp.31-36
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    • 2024
  • Plastics are widely used in industries in human society and because of their structural stability, degradation is a serious global issue. To estimate the degradation of plastic, 31 edible mushrooms were cultured with the selected plastic films (polyethylene [PE], polystyrene [PS], and poly(ethylene terephthalate) [PET]) for 3 months at 25 ℃. Measuring the weight of the films showed that four species of mushrooms, namely Porostereum spadiceum, Ganoderma lucidum, Coprinellus micaceus, and Pleurotus ostreatus, exhibited the highest degrees of plastic degradation. In addition, the mushrooms and fungi that exhibited the most significant plastic degradation were cross-cultured to promote this degradation. As a result, cross-cultivation of G. lucidum and Aspergillus niger showed a weight loss of 2.49% for the PET film. For the PS film, Aspergillus nidulans showed a weight loss of 4.06%. Cross-cultivation of A. nidulans and C. micaceus, which showed a weight loss of 2.95%, was noted as an alternative for PS biodegradation, but is harmful to humans. These bio-degradation effects of edible mushroom will contribute to the development of alternatives for eco-friendly plastic degradation.

Usability test of pulling cable exercise machine in the spinal cord injury disabled: Focusing on deriving improvement (척수 손상 장애인 대상 장애인용 풀링 케이블 운동기구의 사용성 평가: 개선점 도출을 중심으로)

  • Sung Shin Kim;Myo Jung Choi;Hyosun Kweon;Kwang Ok An;Young-Hyeon Bae
    • Journal of Korean Physical Therapy Science
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    • v.31 no.1
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    • pp.16-32
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    • 2024
  • Background: Exercise equipments and assistive devices for the disabled are being developed, but improvements for usability are still needed. The purpose of this study was to improve and utilize the developed exercise equipment and assistance devices by conducting usability test for people with spinal cord injury. Design: Cross-sectional Study. Methods: Scenarios and usability indicators were derived by conducting a preliminary usability test, 5 non-disabled men and women aged 19 or older. In the scenario, a total of 9 tasks were sequentially performed, including 2 tasks of entry and exit, 5 tasks of assistance devices and weight stack adjustment, and 2 tasks of pre exercise and exercise. The usability indicators were task success (success or fail), execution time (sec), safety, and convenience. For safety, 7 questions (Likert scale, 1~5 point) related to safety, stability and hazard were derived, and for convenience, the system usability scale (SUS score) was used (range: 0~100, 50 percentile rank is 68 point). Results: As a result of the usability test of people with spinal cord injury, there was a large variation among subjects in the task of adjusting the position of the pulley and support in the execution time (11.64~25.44 seconds), and one person failed to adjust the pulley. The safety level showed a lower score (score = 3 points) than other items in the item of entrapment or skin pressure, and in the case of SUS, the average score was 64.5 points, which was close to the acceptable level. Conclusion: Through the usability test, it was confirmed that exercise equipment for the disabled needs improvement in operability, pinching, and pressure, and that it is necessary to develop an assistive device that provides unrestrained posture information (biofeedback) to maintain correct posture during exercise.

Development of a Synthetic Method for [68Ga]Ga-FAPI-04 Using a Cassette-based Synthesizer (카세트 기반 자동합성장치를 사용한 [68Ga]Ga-FAPI-04의 합성방법 연구)

  • Jun Young PARK;Won Jun KANG
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.1
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    • pp.43-51
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    • 2024
  • [68Ga]Ga-FAPI-04 is a promising radiopharmaceutical that binds specifically to fibroblast activation protein, which is overexpressed in more than 90% of malignant epithelial tumors but not in normal healthy tissue. This study aimed to develop an efficient method for producing 68Ga-labelled FAPI-04 using a cassette-based automated synthesizer. [68Ga]GaCl3 was eluted from an Eckert & Ziegler Medical germanium-68/gallium-68 generator using 2.5 mL of 0.1 M HCl. The synthesis of the [68Ga]Ga-FAPI-04 was performed using different concentrations of HEPES (1~2.5 M; 4-(2-hydroxyethyl) piperazine-1-ethanesulfonic acid) in 3~10 minutes; amounts of FAPI-04 precursor (5~50 ㎍) and reaction temperature (25℃~100℃) were optimized on the BIKBox® synthesizer. The labeling efficiency of [68Ga]Ga-FAPI-04 was greater than 96% (decay corrected) using 25 ㎍ FAPI-04 synthesized in 10 minutes at 100℃ in 2 M HEPES (pH 3.85), and its stability was greater than 99% at 6 hours. The total synthesis time of [68Ga]Ga-FAPI-04 was 32.4 minutes, and the product met all quality control criteria. In this study, we developed and optimized a labeling method using [68Ga]Ga-FAPI-04 using a cassette-based synthesizer. The devised method is expected to be useful for supplying [68Ga]Ga-FAPI-04 for diagnosis in clinical practice.

Digital interim immediate denture fabrication and implant-supported removable partial denture fabrication after multiple teeth extraction in patient with chronic periodontitis: a case report (만성 치주염 환자에서 다수치 발거 후 디지털 임시 즉시 의치 제작 및 임플란트 지지 가철성 국소의치 수복 증례)

  • Min-Jae Park;Ji-Won Bang;Joo-Hyuk Bang;Seon-Young Lim;Yong-Sang Lee;Keun-Woo Lee;Sung-Yong Kim
    • The Journal of Korean Academy of Prosthodontics
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    • v.62 no.2
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    • pp.104-112
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    • 2024
  • When teeth are extracted, patient face social, psychological and aesthetic problems which can be minimized by fabricating a interim immediate denture. Interim immediate denture manufactured using digital technology can be completed with reduced number of patients' visits and simple laboratory process. Implant-supported removable partial denture (ISRPD) has been suggested as alternative treatment option when fixed implant prosthesis is not feasible. In this case, interim immediate dentures were fabricated using digital technology for patient after teeth extraction and treatment using ISRPD by installing implants and surveyed crowns is found to be successful with better support, stability and maintenance of removable partial dentures.

Impact of postoperative dietary types on nutrition and treatment prognosis in hospitalized patients undergoing oral and maxillofacial surgery: a comparative study

  • Sung Bin Youn;Se-Hui Ahn;Dong-Ho Cho;Hoon Myoung
    • Korean Journal of Community Nutrition
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    • v.29 no.2
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    • pp.129-143
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    • 2024
  • Objectives: The objective of this study is to compare a nutritionally balanced soft blend diet (SBD) with a soft fluid diet (SFD) on the health of inpatients who have undergone oral and maxillofacial (OMF) surgery, ultimately aiming to enhance care outcomes, improve health-related quality of life (QOL), and increase satisfaction with the hospital. Methods: Thirty-two patients were randomized into two groups: sixteen received SFD and sixteen received SBD. Anthropometric, laboratory evaluations were conducted upon admission and discharge. Patients filled out questionnaires on demographics, diet satisfaction, food intake amount, and health-related QOL on the day of discharge, assessed using the EuroQoL 5 Dimensions 3 Level and EuroQoL Visual Analogue Scale (EQ-VAS) instruments. Data were analyzed with descriptive statistics, χ2 tests for group differences, and paired nonparametric t-tests for within-group comparisons. The Mann-Whitney U test evaluated inter-group differences in preoperative weight and body mass index (BMI), postoperative changes, meal satisfaction, intake, health-related QOL, and self-assessed health status. P-values were set at a significance level of 0.05. Results: The SBD group had higher dietary intake (63.2% vs. 51.0%) and greater diet satisfaction (80.6 vs. 48.1, P < 0.0001) compared to SFD group. Health-related QOL, measured by EQ-VAS, was better in SBD group (70.3 vs. 58.8, P < 0.05). Postoperative weight and BMI decreased in SFD group but increased in SBD group (P < 0.01). Changes in laboratory results showed more stability in the SBD group. No postoperative infections were reported in SBD group, whereas SFD group had a 31.25% complication rate. Conclusions: While SFD is often recommended after OMF surgery to protect oral wound healing process, our study reveals that SBD not only enhances physical and psychological outcomes but also, somewhat unexpectedly, supports wound healing and reduces complications. Essentially, SBD promotes physical recovery and enhances health-related QOL than SFD by supporting both somatic and mental healing aspects.

A Study on Acoustic Emission and Micro Deformation Characteristics During Biaxial Compression Experiments of Underground Opening Damage (이축압축실험을 통한 지하공동 손상시 음향방출 및 미소변형 특성 연구)

  • Min-Jun Kim;Junhyung Choi;Taeyoo Na;Chan Park;Byung-Gon Chae;Eui-Seob Park
    • Tunnel and Underground Space
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    • v.34 no.2
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    • pp.169-184
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    • 2024
  • This study investigates acoustic emission (AE) and micro-deformation characteristics of circular openings through biaxial compression experiments. The experimental results showed a significant increase in the frequency, count, energy, and amplitude of AE signals immediately before damage occurred in the circular opening. The differences in frequency and count between before and after damage initiation were significantly pronounced, indicating suitable factors for identifying damage occurrence in circular openings. The results for digital image correlation (DIC) technique revealed that micro-deformation was concentrated around the openings, as evidenced by the spatial distribution of strain. In addition, spalling was observed at the end of the experiments. The AE and micro-deformation characteristics presented in this study are expected to serve as fundamental data for evaluating the stability of underground openings and boreholes for deep subsurface projects.

Review of In-situ Installation of Buffer and Backfill and Their Water Saturation Management for a Deep Geological Disposal System of Spent Nuclear Fuel (국외 사례를 통한 사용후핵연료 심층처분시스템 완충재 및 뒤채움재의 현장시공 및 포화도 관리 기술 분석)

  • Ju-Won Yun;Won-Jin Cho;Hyung-Mok Kim
    • Tunnel and Underground Space
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    • v.34 no.2
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    • pp.104-126
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    • 2024
  • Buffer and backfill play an essential role in isolating high-level radioactive waste and retard the migration of leaked radionuclides in deep geological disposal system. A bentonite mixture, which exhibits a swelling property, is considered for buffer and backfill materials, and excessive groundwater inflow from surrounding rock mass may affect stability and efficiency of their role as an engineered barrier. Therefore, stringent quality control as well as in-situ installation management and inflow water constrol for buffer and backfill are required to ensure the safety of deep disposal facilities. In this study, we analyzed the design requirements of buffer and backfill by examining various laboratory tests and a field study of the Steel Tunnel Test at the Äspö Hard Rock Laboratory in Sweden. We introduced how to control the quality of buffer and backfill construction in-field, and also presented how to handle excessive groundwater inflow into disposal caverns, validating the groundwater retention capacity of bentonite pellets and the effectiveness of geotexile use.

Performance assessment of polymeric filler and composite sleeve technique for corrosion damage on large-diameter water pipes (대구경 상수도관 부식 손상부의 고분자 필러와 복합슬리브 성능 평가)

  • Ho-Min Lee;Jeong-Soo Park;Jeong-Joo Park;Cheol-Ho Bae
    • Journal of Korean Society of Water and Wastewater
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    • v.37 no.4
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    • pp.203-214
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    • 2023
  • In this study, the physical properties and fracture characteristics according to the tensile load are evaluated on the materials of the polymeric filler and carbon fiber-based composite sleeve technique. The polymeric filler and the composite sleeve technique are applied to areas where the pipe body thickness is reduced due to corrosion in large-diameter water pipes. First, the tensile strength of the polymeric filler was 161.48~240.43 kgf/cm2, and the tensile strength of the polyurea polymeric filler was relatively higher than that of the epoxy. However, the tensile strength of the polymeric filler is relatively very low compared to ductile cast iron pipes(4,300 kgf/cm2<) or steel pipes(4,100 kgf/cm2). Second, the tensile strength of glass fiber, which is mainly used in composite sleeves, is 3,887.0 kgf/cm2, and that of carbon fiber is up to 5,922.5 kgf/cm2. The tensile strengths of glass and carbon fiber are higher than ductile cast iron pipe or steel pipe. Third, when reinforcing the hemispherical simulated corrosion shape of the ductile cast iron pipe and the steel pipe with a polymeric filler, there was an effect of increasing the ultimate tensile load by 1.04 to 1.06 times, but the ultimate load was 37.7 to 53.7% compared to the ductile cast iron or steel specimen without corrosion damage. It was found that the effect on the reinforcement of the corrosion damaged part was insignificant. Fourth, the composite sleeve using carbon fiber showed an ultimate load of 1.10(0.61T, 1,821.0 kgf) and 1.02(0.60T, 2,290.7 kgf) times higher than the ductile cast iron pipe(1,657.83 kgf) and steel pipe(2,236.8 kgf), respectively. When using a composite sleeve such as fiber, the corrosion damage part of large-diameter water pipes can be reinforced with same level as the original pipe, and the supply stability can be secured through accident prevention.