• Title/Summary/Keyword: Post-investigation reports

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An experimental and numerical investigation on the effect of longitudinal reinforcements in torsional resistance of RC beams

  • Khagehhosseini, A.H.;Porhosseini, R.;Morshed, R.;Eslami, A.
    • Structural Engineering and Mechanics
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    • v.47 no.2
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    • pp.247-263
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    • 2013
  • It is evident that torsional resistance of a reinforced concrete (RC) member is attributed to both concrete and steel reinforcement. However, recent structural design codes neglect the contribution of concrete because of cracking. This paper reports on the results of an experimental and numerical investigation into the torsional capacity of concrete beams reinforced only by longitudinal rebars without transverse reinforcement. The experimental investigation involves six specimens tested under pure torsion. Each specimen was made using a cast-in-place concrete with different amounts of longitudinal reinforcements. To create the torsional moment, an eccentric load was applied at the end of the beam whereas the other end was fixed against twist, vertical, and transverse displacement. The experimental results were also compared with the results obtained from the nonlinear finite element analysis performed in ANSYS. The outcomes showed a good agreement between experimental and numerical investigation, indicating the capability of numerical analysis in predicting the torsional capacity of RC beams. Both experimental and numerical results showed a considerable torsional post-cracking resistance in high twist angle in test specimen. This post-cracking resistance is neglected in torsional design of RC members. This strength could be considered in the design of RC members subjected to torsion forces, leading to a more economical and precise design.

Experimental Investigation on the Ultimate and PostUltimate Strength of Stiffened Plates under Axial Compression

  • Cho, Sang-Rai;Song, Ick-Cho
    • Journal of Ship and Ocean Technology
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    • v.7 no.1
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    • pp.1-12
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    • 2003
  • Stiffened plates are among the most popular structural elements for marine structures like ships or offshore platforms. Many researchers have performed and reported the results of structural tests on stiffened plates in the open literature. However, the behaviour of stiffened plates in post-ultimate regime has not been fully reported. This paper reports the results of twenty-one axial compression tests including the initial imperfections and material properties of the test models. In aiming to investigate the post-ultimate behaviour of stiffened panels, the axial shortenings were increased up to far beyond the ultimate state. The results obtained from these tests can be utilized in substantiating design formulae in predicting the post-ultimate behaviour of stiffened plates.

Post buckling mechanics and strength of cold-formed steel columns exhibiting Local-Distortional interaction mode failure

  • Muthuraj, Hareesh;Sekar, S.K.;Mahendran, Mahen;Deepak, O.P.
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.621-640
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    • 2017
  • This paper reports the numerical investigation conducted to study the influence of Local-Distortional (L-D) interaction mode buckling on post buckling strength erosion in fixed ended lipped channel cold formed steel columns. This investigation comprises of 81 column sections with various geometries and yield stresses that are carefully chosen to cover wide range of strength related parametric ratios like (i) distortional to local critical buckling stress ratio ($0.91{\leq}F_{CRD}/F_{CRL}{\leq}4.05$) (ii) non dimensional local slenderness ratio ($0.88{\leq}{\lambda}_L{\leq}3.54$) (iii) non-dimensional distortional slenderness ratio ($0.68{\leq}{\lambda}_D{\leq}3.23$) and (iv) yield to non-critical buckling stress ratio (0.45 to 10.4). The numerical investigation is carried out by conducting linear and non-linear shell finite element analysis (SFEA) using ABAQUS software. The non-linear SFEA includes both geometry and material non-linearity. The numerical results obtained are deeply analysed to understand the post buckling mechanics, failure modes and ultimate strength that are influenced by L-D interaction with respect to strength related parametric ratios. The ultimate strength data obtained from numerical analysis are compared with (i) the experimental tests data concerning L-D interaction mode buckling reported by other researchers (ii) column strength predicted by Direct Strength Method (DSM) column strength curves for local and distortional buckling specified in AISI S-100 (iii) strength predicted by available DSM based approaches that includes L-D interaction mode failure. The role of flange width to web depth ratio on post buckling strength erosion is reported. Then the paper concludes with merits and limitations of codified DSM and available DSM based approaches on accurate failure strength prediction.

Hospital-Acquired Measles: A Systematic Review Using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) Statement

  • Erdenetuya Bolormaa;Cho Ryok Kang;Han Ho Kim;Young June Choe
    • Pediatric Infection and Vaccine
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    • v.31 no.1
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    • pp.64-74
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    • 2024
  • Purpose: Despite the recent increased number of nosocomial measles, the outbreak investigation reports are not usually standardized, thus posing unclear understanding of magnitude of its public health burden. We used the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement, to compare nosocomial outbreaks and synthesize evidence to prevent hospital transmission of measles. Methods: A PubMed, Web of Science, Embase, Scopus, and Cochrane search in English, using the medical subject headings "measles," "nosocomial," "hospital," and "healthcare," was performed. We evaluated the quality of outbreak reports of nosocomial measles infection worldwide using the ORION statement findings and recommendations. Results: We reviewed 24 studies in accordance to the ORION statement. Measles transmission in healthcare settings is a significant burden on the morbidity, mortality, and economy of measles. The healthcare workers' booster vaccination guidelines should be monitored and enhanced during the post-elimination period of measles. The outcomes of infections must be explicit for outbreak reports. Conclusions: This study identified the epidemiological and clinical characteristics of nosocomial measles infections and provided strong evidence for infection control policies in hospitals.

Safety Culture: A Retrospective Analysis of Occupational Health and Safety Mining Reports

  • Tetzlaff, Emily J.;Goggins, Katie A.;Pegoraro, Ann L.;Dorman, Sandra C.;Pakalnis, Vic;Eger, Tammy R.
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.201-208
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    • 2021
  • Background: In the mining industry, various methods of accident analysis have utilized official accident investigations to try and establish broader causation mechanisms. An emerging area of interest is identifying the extent to which cultural influences, such as safety culture, are acting as drivers in the reoccurrence of accidents. Thus, the overall objective of this study was to analyze occupational health and safety (OHS) reports in mining to investigate if/how safety culture has historically been framed in the mining industry, as it relates to accident causation. Methods: Using a computer-assisted qualitative data analysis software, 34 definitions of safety culture were analyzed to highlight key terms. Based on word count and contextual relevance, 26 key terms were captured. Ten OHS reports were then analyzed via an inductive thematic analysis, using the key terms. This analysis provided a concept map representing the 50-year data set and facilitated the use of text framing to highlight safety culture in the selected OHS mining reports. Results: Overall, 954 references and six themes, safety culture, attitude, competence, belief, patterns, and norms, were identified in the data set. Of the 26 key terms originally identified, 24 of them were captured within the text. The results made evident two distinct frames in which to interpret the data: the role of the individual and the role of the organization, in safety culture. Conclusion: Unless efforts are made to understand and alter cultural drivers and share these findings within and across industries, the same accidents are likely to continue to occur.

Long noncoding RNA: multiple players in gene expression

  • Chen, Xiaochang;Sun, Yunmei;Cai, Rui;Wang, Guoqiang;Shu, Xiaoyan;Pang, Weijun
    • BMB Reports
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    • v.51 no.6
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    • pp.280-289
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    • 2018
  • Previously considered as a component of transcriptional noise, long noncoding RNAs (lncRNAs) were neglected as a therapeutic target, however, recently increasing evidence has shown that lncRNAs can participate in numerous biological processes involved in genetic regulation including epigenetic, transcriptional, and post-transcriptional regulation. In this review, we discuss the fundamental functions of lncRNAs at different regulatory levels and their roles in metabolic balance. Typical examples are introduced to illustrate their diverse molecular mechanisms. The comprehensive investigation and identification of key lncRNAs will not only contribute to insights into diseases, such as breast cancer and type II diabetes, but also provide promising therapeutic targets for related diseases.

EFFECTIVENESS ANALYSIS OF GROUND IMPROVEMENT TREATED BY DYNAMIC CONSOLIDATION (동압밀공법을 이용한 지반개량 사례연구)

  • 양정수;손준익
    • Proceedings of the Korean Geotechical Society Conference
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    • 1992.10a
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    • pp.137-144
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    • 1992
  • This paper reports a case study of dynamic consolidation. The objective of the study is to evaluate the effectiveness of ground improvement at the site for Hyundai Petrochemical Compound constructed at Daesan-Myeon, Seosan-Gun in the western shores of Korea. The site ground was prepared by filling on the existing soft marine deposit which consists of a loose granular soil layer and a medium stiff clay layer. For the stabilization of site ground, the compaction was executed in three different procedures with same pounder weigh, drop height and imprint spacing. The post investigation showed that the object was successfully achieved indicating a significant increase of bearing capacity of the treated ground. In this study the effectiveness of dynamic consolidation is evluated for various factors the applied energy, temping sequences, the radial distance from the imprint location and the depth of bed rock.

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Development and Application of Tutorial for Conceptual Change on Object Recognition of Scientific Gifted in Elementary School (초등과학 영재의 물체 인식 개념 변화를 위한 튜토리얼의 개발과 적용)

  • Lee, Ji-Won;Kim, Jung-Bok
    • Journal of Korean Elementary Science Education
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    • v.30 no.3
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    • pp.340-352
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    • 2011
  • The purpose of this study was to analyze effects of teaching materials for elementary science gifted conception about object recognition. Elementary science gifted have misconceptions that they can see in lightness. They can not explain how a shadow is made. This paper reports in-depth investigation on elementary science gifted's understanding of object recognition focusing on process of light. A program is developed to elementary science gifted in the subject matter. The tutorial emphasizing the process of light consists of pre-test, worksheet, and post-test. The Tutorial has 4 steps; darkness and light, light on things, light reached eyes, structure of the eyes. Each steps has 2~4 experiments. Through the tutorial, we expect their misconceptions can be changed into scientific conceptions. For the research and analysis, a questionnaire is posed to 39 elementary science gifted at M Elementary School in D Metropolitan City. The first method of product analysis makes a comparative study of pre-test, post-test score, and hake gain each test. As a result, total score of all student was raised. And hake gain of pre-test(II) is 0.6, hake gain of post-test is 0.68. It is Medium gain. Also, elementary science gifted could understand how we see through the tutorial emphasizing process of light. And their misconceptions can be changed into scientific conceptions.

Indications, Outcomes, and Complications of Pedicled Propeller Perforator Flaps for Upper Body Defects: A Systematic Review

  • Lazzeri, Davide;Huemer, Georg M.;Nicoli, Fabio;Larcher, Lorenz;Dashti, Talal;Grassetti, Luca;Li, Qingfeng;Zhang, Yixin;Spinelli, Giuseppe;Agostini, Tommaso
    • Archives of Plastic Surgery
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    • v.40 no.1
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    • pp.44-50
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    • 2013
  • Background The aim of this investigation was to systematically review the current literature to provide the best data for indications, outcomes, survival, and complication rates of pedicled propeller perforator flaps for upper body defects. Methods A comprehensive literature review for articles published from January 1991 to December 2011 was performed using the PubMed, Medline, and Cochrane Databases. Articles without available full-text, single case reports or papers with excessive missing data were excluded. Papers reporting pedicle-perforator (propeller) flaps used for lower extremity reconstruction were excluded from meta-analysis. Results From the initial 1,736 studies our search yielded, 343 studies qualified for the second stage of selection. Of 117 full-text reports screened, 41 studies, met the definitive inclusion and exclusion criteria. Of the selected 41 articles, 26 were case series, original papers or retrospective reviews and were included, whereas 15 were case report papers and therefore were excluded. Two hundred ninety-five propeller flaps were reported to have been used in a total of 283 patients. Indications include repair of trauma-induced injuries, post-trauma revision surgery, cancer resection, chronic infection, pressure sores, and chronic ulcers with a major complication rate (3.3%) comparable to that of free flaps. No specific exclusion criteria for the procedure were presented in the studies reviewed. Conclusions Pedicled propeller flaps are a versatile and safe reconstructive option that are easy and quick to raise and that provide unlimited clinical solutions because of the theoretical possibility of harvesting them based on any perforator chosen among those classified in the body.

Investigation of the effect of Staufen1 overexpression on the HIV-1 virus production

  • Park, Seong-won;Yu, Kyung-Lee;Bae, Jun-Hyun;Kim, Ga-Na;Kim, Hae-In;You, Ji Chang
    • BMB Reports
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    • v.54 no.11
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    • pp.551-556
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    • 2021
  • In this study, we investigated how Staufen1 influences the HIV-1 production. The overexpression of Staufen1 increased virus production without any negative affect on the viral infectivity. This increase was not caused by transcriptional activation; but by influencing post-transcriptional steps. Using multiple Gag protein derivatives, we confirmed that the zinc-finger domains of the HIV-1 nucleocapsid (NC) are important for its interaction with Staufen1. We also found that Staufen1 colocalized in stress granules with the mature form of the HIV-1 NC protein.