• Title/Summary/Keyword: distributed damage

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Study for defensive effect of Jowesungcheong-tang on gastric mucosal damage in mice (조위승청탕(調胃升淸湯)의 위점막(胃粘膜) 손상(損傷) 방어효과(防禦效果)에 관한 연구(硏究))

  • Park, Seoung-Sik;Han, Jin-Soo
    • Journal of Sasang Constitutional Medicine
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    • v.14 no.1
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    • pp.100-111
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    • 2002
  • 1. The Purpose of study An experimental study has done to examine the effect of defense on gastric mucosal damage of Jowesungcheong-tang. 2. The Material and Method of study Mice had intragastric injected with JST extract before indome thacin treatment which induces hemorrh age erosion artificially. General morphology, infiltrative cell in mucosa, the distribution of UEA-I, COX-1, MAC-1. ICAM, and Apoptotic cell were objected (Ahhreviation) JST :Jowesungcheong-tang, UEA-I : ulex europaeus agglutinin-I, COX-1: cyclooxyhenase-1, ICAM : intercellular adhesion molecule-1, GPE : Gastropathy elicitated mice 3. The results and Conclusions of study 1) The degree of hemorrhage erosion in GPE-group had increased conspicuously in gastric gland proper. JST -group were the same as normal 2) The noticeable increase of granular lecocytes and lymphocytes in GEP-group were seen, but in JST group, the configuration is decreased 3) The decrease of UEA-I positive reacted cells, COX-1, surface epithelial cells and the increase of MAC-l positive cells, ICAM-l positive cells had shown in GPE-group, but in JST-group UEA-I positive cells, COX-1 surface epithelial cells were in creased and MAC-1 positive cells, ICAM-l positive cells were decreased than GPE-group. 4) A number of apoptotic cells were distributed in hemorrhage erosion. The remarkable decrease of apoptotic cells were shown in JST-group.

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Computer Simulaton of Defect Formation Behaviors of Crystal-Silicon on the Low Energy Arsenic Implantation by Molecular Dynamics (분자동력학적 방법에 의한 저 메너지 As 이온 주입에 따른 Si 기판의 결함 형성 거동에 대한 컴퓨터 모사 실험)

  • Chung, Dong-Seok;Park, Byung Do
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.4
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    • pp.259-264
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    • 2000
  • In this study, we quantitatively measure the ion ranges of arsenic with energies ranging from 10 KeV to 100 KeV, implanted at $3^{\circ}$, $9^{\circ}$ $15^{\circ}$ the (100) plane, and the damage created during ion implantation. To obtain detailed information of ion range and damage distributions in low energy region where elastic collisions dominate the slowing down process, molecular dynamics computer simulation was performed and compared to the existing results. The effects of implant energy and degree on damage generation are present. The number of vacancy were calculated from the deposited energy using Kinchin-Pease equation. In the energy range 10 keV-100 keV, simulations show that the number of Frenckel pairs produced by As-ion bimbardment is 9 and incident angle dependence of the vacancy was the same but defects were distributed at different depth.

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Effects of viscous damping models on a single-layer latticed dome during earthquakes

  • Zhang, Huidong;Wang, Jinpeng;Zhang, Xiaoshuai;Liu, Guoping
    • Structural Engineering and Mechanics
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    • v.62 no.4
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    • pp.455-464
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    • 2017
  • Rayleigh damping model is recommended in the recently developed Performance-Based Earthquake Engineering (PBEE) methodology, but this methodology does not provide sufficient information due to the complexity of the damping mechanism. Furthermore, each Rayleigh-type damping model may have its individual limitations. In this study, Rayleigh-type damping models that are used widely in engineering practice are discussed. The seismic performance of a large-span single-layer latticed dome subjected to earthquake ground motions is investigated using different Rayleigh damping models. Herein a simulation technique is developed considering low cycle fatigue (LCF) in steel material. In the simulation technique, Ramberg-Osgood steel material model with the low cycle fatigue effect is used to simulate the non-uniformly distributed material damping and low cycle fatigue damage in the structure. Subsequently, the damping forces of the structure generated by different damping models are compared and discussed; the effects of the damping ratio and roof load on the damping forces are evaluated. Finally, the low cycle fatigue damage values in sections of members are given using these damping models. Through a comparative analysis, an appropriate Rayleigh-type damping model used for a large span single-layer latticed dome subjected to earthquake ground motions is determined in terms of the existing damping models.

Distribution of Acoustic Emission Parameters during Load Holding for CNG Vehicle Fuel Tank (CNG 연료탱크의 내압상승시 발생하는 음향방출 변수들의 분포)

  • Jee, Hyun-Sup;Lee, Jong-O;Ju, No-Hoe;Lee, Jong-Kyu;So, Cheal-Ho
    • Korean Journal of Materials Research
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    • v.21 no.11
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    • pp.623-627
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    • 2011
  • This is a study on the distribution of acoustic emission parameters during a burst test for a type-II CNG vehicle fuel tank. A resonant AE sensor with a central frequency of 150 kHz was attached to the composite materials in the center of the fuel tank. The pressure was increased from 30 to 100% of the expected burst pressure and was maintained for 10 minutes at each level. Damage at 70% of expected burst pressure occurred by various damage mechanisms including fiber breakage and delamination, while that of below 60% only occurred by matrix crack initiation and growth. The count, duration and rise time of the AE signal at 60% of the expected burst pressure are distributed below 500, 5000 ${\mu}s$ and 300 ${\mu}s$, respectively. Then, at above 70% they increased with pressure by superimposing of individual AE signal generated at a nearby place. These results confirmed that the analysis of the distribution of AE parameters is an effective tool for estimating damage of a CNG fuel tank.

Seismic vulnerability assessment of RC buildings according to the 2007 and 2018 Turkish seismic codes

  • Yon, Burak
    • Earthquakes and Structures
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    • v.18 no.6
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    • pp.709-718
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    • 2020
  • Fragility curves are useful tools to estimate the damage probability of buildings owing to seismic actions. The purpose of this study is to investigate seismic vulnerability of reinforced concrete (RC) buildings, according to the 2007 and 2018 Turkish Seismic Codes, using fragility curves. For the numerical analyses, typical five- and seven-storey RC buildings were selected and incremental dynamic analyses (IDA) were performed. To complete the IDAs, eleven earthquake acceleration records multiplied by various scaling factors from 0.2g to 0.8g were used. To predict nonlinearity, a distributed hinge model that involves material and geometric nonlinearity of the structural members was used. Damages to confined concrete and reinforcement bar of structural members were obtained by considering the unit deformation demands of the 2007 Turkish Seismic Code (TSC-2007) and the 2018 Turkey Building Earthquake Code (TBEC-2018). Vulnerability evaluation of these buildings was performed using fragility curves based on the results of incremental dynamic analyses. Fragility curves were generated in terms of damage levels occurring in confined concrete and reinforcement bar of structural members with a lognormal distribution assumption. The fragility curves show that the probability of damage occurring is more according to TBEC-2018 than according to TSC-2007 for selected buildings.

The effects of verbal violence on stress among dental hygienists and mediating effects of positive psychological capital (언어폭력이 치과위생사의 스트레스에 미치는 영향과 긍정심리자본의 매개)

  • Park, Jung-Hyun;Jang, Kyeung-Ae
    • Journal of Korean society of Dental Hygiene
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    • v.19 no.2
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    • pp.241-249
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    • 2019
  • Objectives: This study aimed to investigate the effects of verbal violence experience on stress and positive psychological capital as well as the mediating effects of positive psychological capital. Methods: A survey was conducted with dental hygienists working at university hospitals, general hospitals, and dental hospitals and clinics in Busan, Gyeongnam, and Ulsan areas.Of the 230 questionnaires distributed, 206 were used in the analysis after excluding 24 completed questionnaires that had errors or missing answers. Results: As a result of identifying the relationships between verbal violence damage, positive psychological capital, and stress, verbal violence damage was negatively correlated with positive psychological capital (r=-0.28, p<0.001) and positively correlated with stress (r=0.40, p<0.001). Positive psychological capital had a negative correlation with stress (r=-0.25, p<0.001). As a result of verifying the mediating effects of positive psychological capital on the relationship between verbal violence damage and stress among dental hygienists, it was found that verbal violence had a significant effect on stress and positive psychological capital in the first and second stages. In the third stage, the effect of positive psychological capital on stress was significant, showing that there was a mediating effect. Conclusions: Therefore, sound work environments should aim to reduce verbal violence while increasing support systems to reduce negative emotional and psychological states.

Acoustic Emission Signal Analysis for Damage Assessment of the Reinforced Concrete Slab Structures (철근 콘크리트 슬래브 구조 손상 평가를 위한 음향방출 신호분석)

  • Kim, Jeong-Hee;Han, Byeong-Hee;Seo, Dae-Cheol;Yoon, Dong-Jin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.4
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    • pp.360-367
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    • 2009
  • The acoustic emission(AE) behavior of reinforced concrete slab under flexural loading was investigated to assess the integrity. This study was aimed at identifying the characteristics of AE response associated with damage development. By applying cyclic loading in various load steps, it was able to differentiate each AE source such as distributed micro crack initiation, friction, flexural crack and localized diagonal tension crack. The secondary peak and the change of AE hit rate gave valuable criteria fur assessment. From the analysis of the felicity ratio, furthermore, it was shown that this values can be used for evaluating the degree of concrete damage. Based on the experimental results, this approach for practical AE application may provide a promising method for estimating the level of damage and distress in concrete structures.

Aircraft and spacecraft structural analysis with hybrid criterion of smart control

  • C.C., Hung;T., Nguyen
    • Advances in aircraft and spacecraft science
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    • v.9 no.6
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    • pp.553-569
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    • 2022
  • In this article, we propose a criterion for ensuring the asymptotic stability of large multiple delays, based on the direct Lyapunov method. Based on this criterion and distributed control scheme, the controllers are synthesized by the PDC to stabilize these large-scale systems with multiple delays. And we focus on the results which shows the high effective by the proposed theory utilized for damage propagation for aircraft structural analysis of composite materials. Finally, the numerical simulations confirmed the effectiveness of the method.

Comparison of Impedance Parameters and Occupational Therapy Evaluation in the Paretic and Non-paretic Upper Extremity of Hemiplegic Stroke Patients

  • Yoo, Chan-Uk;Kim, Jaehyung;Hwang, Youngjun;Kim, Gunho;Shin, Yong-Il;Jeon, Gyerok
    • Journal of Korea Multimedia Society
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    • v.20 no.12
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    • pp.1980-1991
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    • 2017
  • Many stroke patients undergoing rehabilitation therapy require a quantitative indicator for the evaluation of body function in paretic and non-paretic regions. In this study, the impedance parameters were acquired to assess the physical status in the upper extremity of thirty six stroke patients with hemiplegia caused by cerebral hemorrhage (10 patients) and cerebral infarction (26 patients), using bioelectrical impedance. Prediction marker (PM), phase angle (PA), PM/PA, and resistance (R) versus reactance ($X_c$) were utilized to evaluate the functional status of the paretic and non-paretic regions. In addition, the hand grip strength (HGS) and the pinch strength (lateral, palmer, tip) were measured on the upper extremity of hemiplegic stroke patients. PM was distributed in inversely proportional to HGS, but PA was distributed in proportional to HGS. However, there were a number of patients with HGS of 0, regardless of the impedance parameters (PM, PA, R vs. $X_c$). Paretic and non-paretic status in upper extremity of these patients could not be analyzed using impedance parameters. At the rehabilitation therapist's instructions, they were unable to move the hand and fingers of the paretic upper extremity by cranial nerve damage, motor nerve damage, and severe cognitive decline.

Studies on The Molds Affecting To The Cotton Textiles (면사제품(綿絲製品)에 번식(繁殖)하는 미생물(微生物)에 관(關)한 연구(硏究))

  • Han, Young-Ku
    • Applied Biological Chemistry
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    • v.13 no.3
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    • pp.243-256
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    • 1970
  • Nowadays, the damages caused by molds in cotton textile goods becomes influential. In our country, however, the relations between cotton goods and molds are not investigated and studied in detail. Two hundred and fifty seven kind of mold's samples were collected in ninety places through the whole country. The molds samples are mainly gathered according to each regions and seasons from molded cotton textiles. Out of this samples, we isolated six hundred and seventy two strains of molds and the results of isolation are following. 1. The distributed molds were Aspergillus sp., Rhizopus sp., Penicillium sp., etc. among them Aspergillus sp. were most widely distributed, and next were Rhizopus sp., Penicillium sp. etc. 2. The distribution of Aspergillus sp. abounded peculiarly in the dry season, while Rhizopus sp. in the rainy season. 3. The C.M.C, descomposing enzymes forming activity on molds were greatly concerned with intensity damage of cotton textile goods. 4. The formation of C.M.C. decomposing enzyme was only influenced by physiology of each strains. 5. Regarding to the growth. a. The molds which were saprophyting on the cotton textile goods were indicated vigorous growing. b. Among isolated six hundred and seventy two strains, there were above a hundred strains which produced pigment and nearly half of them fifty nine strains were Aspergillus sp. 6. Twenty one strains in isolated six hundred and seventy two strains were indentified which can heavily damage upon cotton textile. As a results of indentification of the selected strains, the following species was abtained, Aspergillus sydowi, wentii, niger, luchuensis, flavus, fumigatus, nidulans, Penicillium frequentants, roqueforti, chrysogenum, albicans, Rhizopus oligosporus, delemar, Mucor rouxii, mucedo, Neurospora sitophila, Monilia variabilis, fructigena, Cladsporium hurbarum and Aspergillus spp. Mucor spp.

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