• Title/Summary/Keyword: Deterioration factors

Search Result 650, Processing Time 0.05 seconds

Influencing Factors on Suicide Ideation among High School Students (고등학생들의 자살생각에 영향을 미치는 관련요인)

  • Song, Sung-Ho;Kang, Chang-Yeol;Lee, Tae-Yong;Kwon, In-Sun
    • Journal of agricultural medicine and community health
    • /
    • v.36 no.1
    • /
    • pp.1-12
    • /
    • 2011
  • Objectives: The purpose of this study was to find out the suicide ideation of high school students in urban and rural areas, and especially to research the relationship between suicide ideation, and general characteristics, characteristics of school life, and empirical characteristics of suicide. Methods: This research targeted four urban and four rural high schools in two cities. The study subjects were 1,114 students in urban area and 968 students in rural area, total 2,082 students. The survey was conducted from July 1, 2009 to July 31, 2009. For statistical analysis, chi-square test, t-test and ANOVA were used for investigating related factors with suicide ideation in urban and rural areas, respectively, with multiple logistic regression for multivariate analysis. Results: The results showed that 38.8% of respondents had suicide ideation within 1 year. The percentage of female students (44.8%) was significantly higher than that of male students (33.4%). However, there was no significant difference between urban (38.0%) and rural area (39.9%). The significant influencing factors on suicide ideation in multiple logistic regression were gender [female student OR(odds ratio)=1.80 (95% CI 1.31-2.47) compared with male student] and grade [second year OR=1.40 (95% CI 0.98-2.00), third year OR=2.15 (95% CI 1.49-3.12) compared with first year] in urban area. Those in rural area were gender [female student OR(odds ratio)=2.71 (95% CI 1.23-2.38) compared with male student], economic deterioration [yes OR=1.81 (95% CI 1.24-2.64) compared with no], and grade [second year OR=2.80 (95% CI 1.82-4.32), third year OR=3.84 (95% CI 2.52-5.87) compared with first year]. Conclusions: This study showed about 40% of high school students had suicide ideation within 1 year. A suicide prevention program may be implemented considering factors related with suicide ideation identified in this study.

A Study on Change in Cement Mortar Characteristics under Carbonation Based on Tests for Hydration and Porosity (수화물 및 공극률 관측 실험을 통한 시멘트모르타르의 탄산화 특성 변화에 대한 연구)

  • Kwon, Seung-Jun;Song, Ha-Won;Park, Sang-Soon
    • Journal of the Korea Concrete Institute
    • /
    • v.19 no.5
    • /
    • pp.613-621
    • /
    • 2007
  • Due to the increasing significance of durability, much researches on carbonation, one of the major deterioration phenomena are carried out. However, conventional researches based on fully hardened concrete are focused on prediction of carbonation depth and they sometimes cause errors. In contrast with steel members, behaviors in early-aged concrete such as porosity and hydrates (calcium hydroxide) are very important and may be changed under carbonation process. Because transportation of deteriorating factors is mainly dependent on porosity and saturation, it is desirable to consider these changes in behaviors in early-aged concrete under carbonation for reasonable analysis of durability in long term exposure or combined deterioration. As for porosity, unless the decrease in $CO_2$ diffusion due to change in porosity is considered, the results from the prediction is overestimated. The carbonation depth and characteristics of pore water are mainly determined by amount of calcium hydroxide, and bound chloride content in carbonated concrete is also affected. So Analysis based on test for hydration and porosity is recently carried out for evaluation of carbonation characteristics. In this study, changes in porosity and hydrate $(Ca(OH)_2)$ under carbonation process are performed through the tests. Mercury Intrusion Porosimetry (MIP) for changed porosity, Thermogravimetric Analysis (TGA) for amount of $(Ca(OH)_2)$ are carried out respectively and analysis technique for porosity and hydrates under carbonation is developed utilizing modeling for behavior in early-aged concrete such as multi component hydration heat model (MCHHM) and micro pore structure formation model (MPSFM). The results from developed technique is in reasonable agreement with experimental data, respectively and they are evaluated to be used for analysis of chloride behavior in carbonated concrete.

Midterm Results of the Bioprosthesis in Mitral Position (조직판막을 이용한 승모판 치환술의 중기 성적)

  • Cho, Hyun-Jin;Lee, Jae-Won;Jung, Sung-Ho;Je, Hyoung-Gon;Choo, Suk-Jung;Song, Hyun;Chung, Cheol-Hyun
    • Journal of Chest Surgery
    • /
    • v.41 no.6
    • /
    • pp.695-702
    • /
    • 2008
  • Background: The choice between a bioprosthetic and a mechanical valve is an important decision in cardiac valve surgery, and the durability of the tissue valve is a major decision factor. We retrospectively evaluated the midterm results of bioprosthetic valve replacement in the mitral position. Material and Method: The subjects were all patients who had undergone mitral bioprosthesis replacement between July 1989 and August 200.7. Among the 216 patients, there were 236 surgical cases. The mean age was $63{\pm}15$ years, and the male to female ratio was 1 : 3. We retrospectively analyzed hospital and outpatient records such that the total follow-up duration amounted to 760.2 patient-years, and the mean follow-up duration was $41.9{\pm}40.7$ months (range $0{\sim}212$ months). Result: Early death occurred in 18 patients (8.3%), and 13 of these underwent concomitant cardiac procedures. The survival rate after 5 years was $79.9{\pm}3.5%$, and the survival rate after 8 years was $65.5{\pm}5.5%$, while freedom from structural valve deterioration (SVD) was $96.2{\pm}2.2%$ at 5 years and $85.9{\pm}5.3%$ at 8 years. Freedom from reoperation was $90.6{\pm}1.7%$ at 5 years and $90.4{\pm}4.2%$ at 8 years, while freedom from reoperation for SVD was $98.1{\pm}1.2%$ at 5 years and $92.3{\pm}4.1%$ at 8 years. On multivariate analysis of preoperative risk factors, small valve size (between 25mm and 27mm) was a significant risk factor for reoperation, and low LV ejection fraction (<40%) was a significant risk factor for SVD and mortality. Conclusion: Survival and freedom from reoperation for SVD in mitral bioprosthesis replacement had acceptable midterm results, but freedom from SVD Was relatively low. In particular, since SVD increased sharply at the eighth postoperative year, frequent follow-up and echocardiograms around that time will be helpful for the early detection of SVD. It will be necessary to conduct further studies involving long-term follow-up and more patients.

Trends in the Use of Assessment Tools by Korean Occupational Therapists: Focus on Adult and Older Adult Populations (한국 작업치료사의 평가도구 사용 동향: 성인 및 노인 분야를 중심으로)

  • Ha, Yae-Na;Jeong, Ji-In;Kang, Byoung-Ho;Yoo, Eun-Young
    • Therapeutic Science for Rehabilitation
    • /
    • v.13 no.3
    • /
    • pp.51-67
    • /
    • 2024
  • Objective : This study investigated trends in the use of assessment tools by occupational therapists working with adults and older adults. Methods : Occupational therapists were surveyed to gather data on general characteristics, assessment tool usage, assessment time and frequency, usage trends by area, and education. The tools were categorized by the Occupational Therapy Practice Framework (OTPF) into Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), and play and leisure for occupations, and cognitive functions, motor functions, and psychosocial aspects for client factors. Data from 98 respondents were analyzed using frequency analysis and one-way ANOVA with SAS. Results : Most surveyed occupational therapists worked in university or general hospitals (40.82%). The assessment time per patient was under 30 min (62.25%), and re-assessment frequency was one~three months (68.38%). The most frequently used assessment tools by the OTPF were as follows: ADL: Modified Barthel Index (94.90%), IADL: Canadian Occupational Performance Measure (31.63%), cognitive functions: Mini-Mental Status Examination (89.80%), visual perception: Motor-free Visual Perception Test (56.12%), dementia: Global Deterioration Scale (63.27%), motor functions: Jamar Dynamometer & Pinch Gauge (59.18%), dysphagia: Video Fluoroscopic Swallowing Study (28.57%), physical examination: Range of Motion (59.18%), and psychosocial: Geriatric Depression Scale (33.67%). Conclusion : This study identified the use and rationale of assessment tools for occupational therapy in adults and older adults. These findings aim to enhance the curriculum and continuing education of occupational therapists.

Effects of quality grade, trimming, and packaging method on shelf life of king oyster mushrooms (큰느타리의 품질 등급, 손질 및 포장 방법에 따른 유통 수명)

  • Choi, Ji-Weon;Lee, Ji Hyun;Oh, In-Ho;Lim, Sooyeon;Im, Ji-Hoon;Yang, Hae Jo;Choi, Hyunjin;Shin, Sheob;Hong, Yoon Pyo
    • Journal of Mushroom
    • /
    • v.19 no.3
    • /
    • pp.234-245
    • /
    • 2021
  • To extend the shelf life of king oyster mushrooms for export, we investigated the impacts of mushroom quality grade, fruiting body trimming, and packaging method (tray container sealed packaging vs string-tied OPP bag packaging). Quality is divided into two grades: 1st grade, which is mushrooms adapted by lowering the cultivation temperature to 9~11℃, and 2nd grade, mushrooms held at 13~15℃ prior to harvest. Using selected 1st and 2nd grade mushrooms, 3 treatments were carried out to assess effects of trimming and packaging method. Test groups included 1) trimming plus string-tied OPP bag packaging (Cut & OPP), 2) no trimming plus string-tied OPP bag packaging (Uncut & OPP), and 3) trimming plus tray container sealing packaging (Cut & Tray). Gas composition inside the packaging, changes in quality factors, and sensory evaluation for fresh quality were performed over 42 days of 0℃ storage. Overall freshness was best maintained in the following order: Cut & Tray > Cut & OPP > Uncut & OPP for both 1st and 2nd grade mushrooms. The shelf-life of 1st grade mushrooms was about 30 days for Cut & Tray, 28 days for Cut & OPP, and 21 days for Uncut & OPP. The shelf-life of 2nd grade mushrooms was about 22 days for Cut & Tray, 17 ays for Cut & OPP, and 14 days for Uncut & OPP. Factors affecting fresh mushroom quality included browning of cap and stalk, and mushroom decay index. Browning of the lower part of the stalk, with related color change as noted in a* and b* values were the main factors indicating quality deterioration of king oyster mushrooms.

A Fundamental Study on Evaluation of Web Crippling Strength of Corroded H-Beams (부식 H형 강재의 복부좌굴강도 추정에 관한 기초적 연구)

  • Kim, In-Tae;Shin, Chang-Hee;Cheung, Ji-Young
    • Journal of Korean Society of Steel Construction
    • /
    • v.22 no.5
    • /
    • pp.421-433
    • /
    • 2010
  • The most typical deterioration of steel structures is corrosion damage. However, a method to evaluate residual load-carrying capacity of corroded steel structures is not yet established. It is difficult to check current serviceability and safety of the structures. In this study, compressive tests and finite element analyses were conducted on H-beams with corroded web. Then, the effect of corrosion damage on web crippling strength and evaluation methods of the web crippling strength are studied. Based on the tests, 4 H-beam specimens used in a subway construction site and 9 H-beam specimens with different web-thickness and damaged-height underwent compression-tests. To consider loading and supporting areas in the site, compressive loading was applied in the entire region of the upper and bottom flange in 5 H-beam specimens and applied partially on the regions of the upper and bottom flange in 8 specimens. The finite element analysis of 38 parametric model specimens simulating different corrosion damages was also carried out. From experimental and analytical results, the relationships between corrosion damages in the web and residual web crippling strength are presented. Factors web crippling strength was reduced are formulated by using residual average thickness and the standard deviation of the corroded web thickness. Also, a simple evaluation method of residual web crippling strength was proposed.

A Study on the Worst Stress Condition Test Evaluation of Blowers for Small Stationary Fuel Cell System (소용량 건물용 연료전지시스템 블로워의 가혹조건 평가에 관한 연구)

  • Kim, Kangsoo;Lee, Deokkwon;Lee, Jungwoon;Kim, Eunjung;Kim, Inchan;Kim, Younggyu;Shin, Hunyong
    • Journal of the Korean Institute of Gas
    • /
    • v.16 no.6
    • /
    • pp.34-40
    • /
    • 2012
  • The fuel cell is one of the renewable energy sources. And it is a new source of energy that can be applied to various fuels and continuously supported by the excellent city-gas infrastructure. It is important to improve performances and reliabilities, and reduce the cost of fuel cell systems for commercialization. And, some safety performances of blower domestically produced are evaluated and some improvements are researched to save the cost of fuel cell systems. In this paper, the performance and worst stress condition of blowers are evaluated in operating environment similar to the fuel cell systems. Actually, the correlation of flow, leakage and thermal behavior are evaluated in the worst stress condition at $70^{\circ}C$ and, some major factors of blower degradation such as a motor deterioration, material and structures of the outlet are examined.

A Retrospective Review of the Preventive Effect of Sambok-go on Upper Respiratory Tract infection (삼복고의 상기도감염 예방 효과에 대한 후향적 관찰연구)

  • Han, Jong-Min;Yang, Su-Young;Sung, Hyun-Kyung;Lee, Jin-Woo;Oh, Young-Seon;Kang, Weechang;Park, Yang-Chun
    • Journal of Haehwa Medicine
    • /
    • v.21 no.2
    • /
    • pp.139-147
    • /
    • 2013
  • Objectives: The aim of this study was to investigate the preventive effects of Sambok-go for upper respiratory tract infection. Methods: Sambok-go was performed to outpatients which had visited Daejeon university oriental medicine hospital. The number of participants who received Sambok-go at least once were 85, 21 patients did not receive Sambok-go three times were excluded first. Participants who received treatment three times were 64 patients. After the 2011 winter, 2012.05 we follow-up by telephone, except eight, 56 patients were analyzed. Sambok-go is composed of 8 kinds of medicinal herbs. Each Sambok-go weighs about 1.1g and attatchment surface diameter is about 1.5 cm. Sambok-go was attached to both side of 폐유(肺兪)(BL13), 심유(心兪)(BL15), 폐유(膈兪)(BL17), patients under the age of 15 were attached for an hour, patients over 15 years age were attatched for 3 hours. Results: Among the finally analyzed 56 participants, we compared the number of flu outbreak during winter before and after treatment. Before treatment measured $6.14{\pm}6.57$, after treatment measured $1.57{\pm}1.14$. In conclusion, the number of flu outbreak was significantly decreased(p<0.001). To investigate the effect of worsening factors on the pre-existing upper respiratory diseases, we checked whether the patients had pre-existing upper respiratory diseases. The patients who already had old upper respiratory diseases were 34. The increase in the frequency of deterioration in 5 patients, 4 patients no change, decreased in 24 cases, one patient was unresponsive. After evaluating the satisfaction of The patients who were treated with the Sambok-Go, the 29 cases were very satisfied, the 23 were satisfied, None of the paitents showed dissatisfaction or bad dissatisfaction. Conclusion: Sambok-go seems to be effective in the prevention of URI. Further studies are recommended to confirm this effect.

Improvement of Durability and Change of Pore Structure for Concrete Surface by the Penetrative Surface Protection Agent (함침계 표면보호제에 의한 콘크리트 표면의 세공구조 변화 및 내구성 향상)

  • Kang, Suk-Pyo;Kim, Jung-Hwan
    • Journal of the Korea Concrete Institute
    • /
    • v.18 no.1 s.91
    • /
    • pp.125-132
    • /
    • 2006
  • Recently, surface finishing and protection materials were developed to restore performance of the deteriorated concrete and inhibiting corrosion of the reinforcing-bar. For this purpose, surface protection agent as well as coatings are used. Coatings have the advantage of low Permeability of $CO_2,\;SO_2$ and water. However, for coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, those have a problem with adhesion. On the other hand, surface protection agent penetrates into pore structure in concrete through capillary and cm make a dense micro structure in concrete as a result of filling effect. Furthermore, the chemical reaction between silicate from surface protection agent and cement hydrates can also make a additional hydration product which is ideally compatible with concrete body. The aim of this study is to examine the effect of penetrative surface protection agent(SPA) by evaluating several concrete durability characteristics. The results show that the concrete penetrated surface protection agent exhibited higher durability characteristics for instance, carbonation velocity coefficient, resistance to chemical attack and chloride ion penetration than the plain concrete. These results due to formation of a discontinuous macro-pore system which inhibits deterioration factors of concrete by changed the pore structure(porosity and pore size distributions) of the concrete penetrated surface protection agent.

A Study on the Selection of Factors for Evaluating the Efficiency of Slope Reinforcement Using AHP (AHP 분석을 활용한 비탈면 보강공 성능평가를 위한 중요항목 도출에 관한 연구)

  • Lee, Jonghyun;Kim, Oil;Kim, Jinhwan;Kim, Wooseok;Choi, Junghae
    • The Journal of Engineering Geology
    • /
    • v.29 no.4
    • /
    • pp.531-539
    • /
    • 2019
  • Various slope protect systems are applied to the slope located around the major facility to maintain stability, and the applied these systems play an important role in protecting the structure by ensuring the safety of the slope. Reinforcement techniques ensure complete safety at the time of application to the slope, but over time, it may become difficult to secure safety. In particular, the deterioration of reinforcement systems may significantly reduce the stability of the slope. Therefore, it is necessary to secure the safety of the slope by defining the necessary items for maintenance of the protect systems and verifying them by the field expert. In this study, a group of experts were formed to determine these items and select their importance among them, and based on their data, the importance of each item was selected by Analytic Hierarchy Process (AHP). The selected items are expected to play an important role in the maintenance of reinforcement systems applied to the slope based on the survey items used by experts.