• Title/Summary/Keyword: assessment of safety

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Fatigue wind load spectrum construction based on integration of turbulent wind model and measured data for long-span metal roof

  • Liman Yang;Cong Ye;Xu Yang;Xueyao Yang;Jian-ge Kou
    • Wind and Structures
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    • v.36 no.2
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    • pp.121-131
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    • 2023
  • Aiming at the problem that fatigue characteristics of metal roof rely on local physical tests and lacks the cyclic load sequence matching with regional climate, this paper proposed a method of constructing the fatigue load spectrum based on integration of wind load model, measured data of long-span metal roof and climate statistical data. According to the turbulence characteristics of wind, the wind load model is established from the aspects of turbulence intensity, power spectral density and wind pressure coefficient. Considering the influence of roof configuration on wind pressure distribution, the parameters are modified through fusing the measured data with least squares method to approximate the actual wind pressure load of the roof system. Furthermore, with regards to the wind climate characteristics of building location, Weibull model is adopted to analyze the regional meteorological data to obtain the probability density distribution of wind velocity used for calculating wind load, so as to establish the cyclic wind load sequence with the attributes of regional climate and building configuration. Finally, taking a workshop's metal roof as an example, the wind load spectrum is constructed according to this method, and the fatigue simulation and residual life prediction are implemented based on the experimental data. The forecasting result is lightly higher than the design standards, consistent with general principles of its conservative safety design scale, which shows that the presented method is validated for the fatigue characteristics study and health assessment of metal roof.

Analysis on Wandering Space Design of Elderly Care Facilities for the Elderly with Dementia (치매노인을 위한 노인요양시설의 배회 공간 특성 분석)

  • Kim, Mi-Jung;Lee, So-Young
    • Korean Institute of Interior Design Journal
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    • v.20 no.6
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    • pp.331-339
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    • 2011
  • The purpose of this study was to examine wandering behaviors of the elderly with dementia at elderly care facilities, thus finding out the current status of supportability and safety of wandering space for facility residents and looking into the convenience of management for the control and Support of the elderly with dementia in wandering space, from the aspect of managers. Study methods consisted of literature examination, on-site assessment and investigation, observation and questionnaire survey. And via a questionnaire survey of facility workers at study subject facilities, the current status and facility workers' perception of wandering space and their job-satisfaction were examined. Collected data of 133 respondents were used for analysis. Data were processed with the SPSS 18.0 program, and such analytic techniques as frequency, percentage, mean, multiple response analysis, chi-square test and correlation analysis were carried out. The problems of physical environment of wandering space for the elderly with dementia: First, it is urgent to establish wandering space. Second, thoughtlessly installed chairs in the corridor impeded wandering behaviors. Third, the grips installed in the corridor space were irregular, thus causing inconvenience for wandering behaviors. Thus making residents' use of it difficult. In order to improve these problems, it is necessary to newly or additionally establish wandering space and modify the location of chairs or establish alcoves, thus reducing impedimentary elements for wandering behaviors. Providing a proper wandering space is important for facility residents. And it is also important for facility workers to manage facility residents.

A Study to Assess the Need of Customized Visiting Health Care Services for Children according to Socioeconomic Status in a Province (사회계층에 따른 영유아 맞춤형 방문건강관리사업 요구도)

  • Kim, Hee-Ja;Bang, Kyung-Sook;Yoo, Jae-Soon;Kim, Hyun-Sook;Tak, Yang-Ju;Huh, Bo-Yun
    • Research in Community and Public Health Nursing
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    • v.22 no.2
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    • pp.212-222
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    • 2011
  • Purpose: This study was conducted to survey children's health status and need of customized visiting health care services in one province. Methods: The participants in this study were 237 caregivers of infants and preschoolers. Data were collected at the participant's home or public health center. Results: Many of the children did not receive developmental screening tests or dental examinations. In the beneficiary group, the prenatal checkup rate and children's vaccination rate were lower, and caregivers had more health problems than the other groups. On the assessment of home safety, unsafe conditions were more frequently found in the beneficiary group. The caregivers in the beneficiary group showed lower child rearing confidence than the other groups, and wanted customized visiting health care services most in the areas of developmental screening, regular health check-up and counseling, nutritional supplementation, and oral health care. Conclusion: These results indicate that it is necessary for children and parents in poverty to be provided with professional home visiting interventions for the promotion of child health and prevention of developmental problems and diseases. These findings can be used for developing future customized visiting health care service programs for infants and children in this community area.

User Evaluation of the Farmers' Market Design in the Rural Village Festival - The Perspective of the Universal Design - (농촌마을축제의 농산물 직거래 장터 디자인에 대한 사용자 평가 - 유니버설디자인 관점에서 -)

  • Chae, Hye-Sung;Seo, Ae-Eun
    • Journal of Korean Society of Rural Planning
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    • v.22 no.4
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    • pp.49-60
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    • 2016
  • This study is in order to promote agricultural products sold in the rural village festivals direct transaction marketplace and enabled by a comprehensive user evaluation of the rural village festivals direct transaction marketplaces in universal design perspective, provide a design plan for your care and comfort of a rural village festival Direct Deals Marketplace there is a purpose. Thus, redefining the principles of universal design suitable for direct transactions rural village festival marketplaces, and to do this by reclassifying the design elements of the farmstand-type in a framework was developed 30 questions to evaluate items for Universal Design Evaluation. And, the selection of three villages along the rural village festivals scale and conducted a survey of Universal Design Rating. As a result, the overall assessment was positive for B villages of rural village festival marketplaces direct transactions, there was a significant difference with the other village. In particular, there was a notable difference in the fairness, efficiency, promotional, safety and hygiene. And, there was a significant difference in design elements for directing atmosphere by selling space, product display, hygiene. This paper presents the design suggestions about a rural village festivals farmers' market aspects of universal design for improvement of the marketplace as following, 1) placement for differentiation the markerplace and around sites in the festival place, 2) to build the operating systems of sustainable management for arrangement and organization during the festival, 3) to install the device for maintaining agricultural products freshness 4) to separate the sale of local specialty products and general food products, and 5) to locate the suitable space considering the visitors tour route in the festival place for large-scale festival.

Estimations of Strain-Based J-integral and CTOD for Circumferential Outer Surface Crack in the Weld of Gas Pipeline Under Axial Displacement (축방향 변위가 작용하는 가스 파이프라인 용접부에 존재하는 원주방향 외부표면균열의 변형률 기반 J-적분 및 CTOD 계산)

  • Kim, Kyoung-Min;Park, Ji-Su;Moon, Ji-Hee;Jang, Youn-Young;Park, Seung-Hyun;Huh, Nam-Su
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.1
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    • pp.100-109
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    • 2020
  • Pipelines subjected to ground movement would be easily exposed to large-scale deformation. Since such deformations may cause the pipeline failure, it is important to ensure the safety of pipelines in various operation conditions. However, crack in weld metal have been considered as one of the main causes that can deteriorate the structural integrity of the pipeline. For this reason, the structural integrity of the pipe containing the crack in the weld should be obtained. In order to assess cracked pipe, J-integral and crack-tip opening displacement(CTOD) have been applied widely as the elastic-plastic fracture mechanics parameters representing crack driving force. In this study, engineering solutions to calculate the J-integral and CTOD of pipes with a circumferential outer surface crack in the weld are proposed. For this purpose, 3-dimensional elastic-plastic finite element(FE) analyses have been performed considering the effect of overmatch and width of weld. The shape of the weld was simplified to I-groove, and axial displacement was employed as for loading condition. Based on FE results, the effects of crack size, material properties and width of weldment on J-integral and CTOD were investigated. Additionally, the J-integral and CTOD for I-groove were compared with those for V-groove to examine the effects of the weld shape, and a proportionality coefficient of J-integral and CTOD was calculated from the results of this paper.

A Method of Estimating Radionuclide Accumulation in Coolant Purification System (원자력발전소 냉각수 정화계통의 핵종누적량 예측기법)

  • Whang, Joo-Ho;Lee, Jae-Min
    • Journal of Radiation Protection and Research
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    • v.22 no.3
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    • pp.183-193
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    • 1997
  • The amount and kinds of radionuclide contained in waste volume should be known to prepare for occupational exposure management, perform safety assessment and finally to license a repository. Although the volume of filters and resins are small, activities of them comprise most of the radioactivity that made during power generation. This study aims at developing a method of estimating the radionuclide accumulation at the filters and resins of coolant systems. In this study, accumulated amount of radionuclides is estimated by a computer program which makes use of instantaneous decontamination factor, DF, instead of average DF. A FORTRAN program was developed for the estimation. Data from in-plant source-term measurements at Rancho-Seco nuclear power plant in the United States are employed for verification of the estimating method. And experimental data are employed, too. The instantaneous-DF-method showed smaller error than the average-DF-method. Accumulated amount of radionuclides can be calculated with only the DF and the radionuclide concentration, which are measured periodically according to the operating guide. However, especially, when the operating condition of nuclear power plant changes rapidly, the measuring term of DF and radionuclide should be shortened to ensure the accurate estimation.

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Analysis of Steep Cuts and Slopes in Cemented Sand Using Fracture Mechanics (파괴역학을 이용한 경화모래로 이루어진 사면의 해석)

  • Kim, Tae-Hoon;Kang, Kwon-Soo;Lee, Jong-Cheon
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.161-168
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    • 2003
  • Most natural deposits of sandy soil possess some degree of cementation resulting from the deposition and precipitation of cementing agents. The presence of cementation can have a significant influence on the stiffness and volume change behavior, and the strength of soils. An important feature of deposits of cemented sandy soils is their ability to remain stable in surprisingly high and almost vertical man-made cuts as well as natural slopes. Numerous field observations and studies of failures in slopes of cemented soils have reported that application of conventional analysis techniques of slope stability is inadequate. That is not only due to the fact that the failure surface of the slope is not circular, but also the fact that the average shear stress along the failure surface is much smaller than the shear strength measured in laboratory shear experiments. This observation alerts us to the fact that a mechanism different from conventional Mohr-Coulomb shear failure takes place, which may be related to fracture processes, which in turn are governed by fracture mechanics concepts and theory. In this study, steep slopes in cemented sand were assessed using fracture mechanics concepts. The results showed that FEM coupled with fracture mechanics concepts provides an excellent alternative in the design and safety assessment of earth structures in cemented soils.

Mutagenicity Assessment of Drinking Water in Combination with Flavored Black Tea Bags: a Cross Sectional Study in Tehran

  • Alebouyeh, Farzaneh;Bidgoli, Sepideh Arbabi;Ziarati, Parisa;Heshmati, Masoomeh;Qomi, Mahnaz
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7479-7484
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    • 2015
  • Diseases related to water impurities may present as major public health burdens. The present study aimed to assess the mutagenicity of drinking water from different zones of Tehran, and evaluate possible health risks through making tea with tea bags, by Ames mutagenicity test using TA 100, TA 98 and YG1029 strains. For this purpose, 450 water samples were collected over the period of July to December 2014 from 5 different zones of Tehran. Except for one sample, no mutagenic potential was detected during these two seasons and the MI scores were almost normal (${\leq}1-1.6$) in TA 100, TA 98 and YG1029 strains. Although no mutagenic effects were considered in TA 98 and TA 100 in the test samples of our three evaluated tea bag brands, one sample from a local company showed mutagenic effects in the YG1029 strain (MI=1.7-1.9 and 2) after prolonged (10-15 min.) steeping. Despite the mild mutagenic effect discovered for one of the brand, this cross sectional study showed relative safety of water samples and black tea bags in Tehran. According to the sensitivity of YG1029 to the mutagenic potential of water and black tea, even without metabolic activation by s9 fraction, this metabolizer strain could be considered as sensitive and applicable to food samples for quantitative analysis of mutagens.

A Survey on the Ready-to-Eat Foods' Consumption Practices of University Students and Microbiological Quality Assessment of Kimbab (대학생의 즉석섭취식품류 소비 실태와 김밥류의 미생물학적 품질 평가)

  • Lee, Jin-Hyang;Bae, Hyun-Joo
    • Korean journal of food and cookery science
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    • v.31 no.2
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    • pp.153-161
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    • 2015
  • This study was conducted to investigate the consumption practices of ready-to-eat (RTE) foods and to analyze the microbiological hazard of kimbab, a Korean dish, and the most popular of the RTE foods eaten by participants in this study. A questionnaire was distributed to 230 university students who had previously purchased RTE foods, and 224 were collected (response rate: 97.4%). Statistical analyses were conducted on the questionnaires using the SPSS program, and a total of 135 kimbab products were sampled for aerobic plate counts, coliforms, E. coli, E. coli O157:H7, Staphylococcus aureus, Salmonella spp., and Listeria monocytogenes. The results of the analyses are as follows. Kimbab (87.0%), sandwich (86.4%), hamburger (89.8%), lunchbox (81.5%), and sushi (87.4%) were most often eaten immediately after purchasing. Additionally, the results of the microbiological hazards analysis of kimbab showed that the aerobic plate counts were significantly different according to the purchasing price (p<0.01). The coliform levels were significantly different according to the place of purchase (p<0.01) and the major ingredients of kimbab (p<0.05). In addition, Staphylococcus aureus and E. coli were detected in 5.9% and 5.2% of the tested samples, respectively. However, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes were not detected in any of the samples. In conclusion, the manufacturers of RTE foods should apply the HACCP system for food safety.

Thromboprophylaxis in Abdominoplasty: Efficacy and Safety of a Complete Perioperative Protocol

  • Marangi, Giovanni Francesco;Segreto, Francesco;Poccia, Igor;Campa, Stefano;Tosi, Daniele;Lamberti, Daniela;Persichetti, Paolo
    • Archives of Plastic Surgery
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    • v.43 no.4
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    • pp.360-364
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    • 2016
  • Background Venous thromboembolism, a spectrum of diseases ranging from deep venous thrombosis to pulmonary embolism, is a major source of morbidity and mortality. The majority of cases described in plastic surgery involve abdominoplasty. Risk assessment and prophylaxis are paramount in such patients. General recommendations were recently developed, but the evidence in the literature was insufficient to prepare exhaustive guidelines regarding the medication, dosage, timing, or length of the prophylaxis. Methods A thromboprophylaxis protocol was developed for patients undergoing abdominoplasty. The protocol consisted of preoperative, intraoperative, and postoperative measures. Enoxaparin was administered as chemoprophylaxis in selected patients. The study involved 253 patients. The patients were analyzed for age, body mass index, enoxaparin dosage, risk factors, and complications. Results Deep venous thrombosis was documented in two cases (0.8%). No pulmonary embolism occurred. Three patients (1.2%) presented mild subcutaneous abdominal hematoma within the first postoperative week that spontaneously resorbed with neither aesthetic nor functional complications. Two patients (0.8%) presented severe hematoma requiring surgical re-intervention for drainage and hemostasis revision. Statistical analysis showed no significant correlation between enoxaparin dosage and hematoma (P=0.18) or deep venous thrombosis (P=0.61). Conclusions The described thromboprophylaxis protocol proved to be effective in the prevention of thrombotic events, with an acceptable risk of hemorrhagic complications. Furthermore, it provides new evidence regarding the currently debated variables of chemoprophylaxis, namely type, dosage, timing, and length.