The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Youngjong Kang - One of the best experts on this subject based on the ideXlab platform.
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compressive strength of circular hollow reinforced concrete confined by an internal steel tube
Construction and Building Materials, 2010Co-Authors: Ki Yong Yoon, Youngjong KangAbstract:Abstract When concrete is confined, its strength is enhanced by confining stress. Therefore many researchers have studied the Confinement and its effect in a reinforced concrete (RC) member. However, their research has focused on making confining pressure from the outside of the member. In a hollow RC member, it is impossible to confine its concrete triaxially because it has a hollow section. The concrete in a hollow RC member is usually in the state of biaxially Confinement, and it shows lower strength than the concrete in a solid RC member, which is confined triaxially. In this study, the compressive strength of the concrete in a hollow RC column with an internal steel tube was investigated. The internal tube makes the concrete confined triaxially with internal Confinement. To show the existence and the effect of the internal Confinement, an experiment was performed. Fourteen specimens were tested. The test results showed that the internal Confinement existed and made the concrete in the state of triaxial Confinement.
Joseph Deluca - One of the best experts on this subject based on the ideXlab platform.
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history of solitary Confinement is associated with post traumatic stress disorder symptoms among individuals recently released from prison
Journal of Urban Health-bulletin of The New York Academy of Medicine, 2018Co-Authors: Brian O Hagan, Emily A Wang, Jenerius A Aminawung, Carmen E Albizugarcia, Nickolas Zaller, Sylviah Nyamu, Shira Shavit, Joseph DelucaAbstract:This study assessed the relationship between solitary Confinement and post-traumatic stress disorder (PTSD) symptoms in a cohort of recently released former prisoners. The cross-sectional design utilized baseline data from the Transitions Clinic Network, a multi-site prospective longitudinal cohort study of post-incarceration medical care. Our main independent variable was self-reported solitary Confinement during the participants’ most recent incarceration; the dependent variable was the presence of PTSD symptoms determined by primary care (PC)-PTSD screening when participants initiated primary care in the community. We used multivariable logistic regression to adjust for potential confounders, such as prior mental health conditions, age, and gender. Among 119 participants, 43% had a history of solitary Confinement and 28% screened positive for PTSD symptoms. Those who reported a history of solitary Confinement were more likely to report PTSD symptoms than those without solitary Confinement (43 vs. 16%, p < 0.01). In multivariable logistic regression, a history of solitary Confinement (OR = 3.93, 95% CI 1.57–9.83) and chronic mental health conditions (OR = 4.04, 95% CI 1.52–10.68) were significantly associated with a positive PTSD screen after adjustment for the potential confounders. Experiencing solitary Confinement was significantly associated with PTSD symptoms among individuals accessing primary care following release from prison. Larger studies should confirm these findings.
Ki Yong Yoon - One of the best experts on this subject based on the ideXlab platform.
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compressive strength of circular hollow reinforced concrete confined by an internal steel tube
Construction and Building Materials, 2010Co-Authors: Ki Yong Yoon, Youngjong KangAbstract:Abstract When concrete is confined, its strength is enhanced by confining stress. Therefore many researchers have studied the Confinement and its effect in a reinforced concrete (RC) member. However, their research has focused on making confining pressure from the outside of the member. In a hollow RC member, it is impossible to confine its concrete triaxially because it has a hollow section. The concrete in a hollow RC member is usually in the state of biaxially Confinement, and it shows lower strength than the concrete in a solid RC member, which is confined triaxially. In this study, the compressive strength of the concrete in a hollow RC column with an internal steel tube was investigated. The internal tube makes the concrete confined triaxially with internal Confinement. To show the existence and the effect of the internal Confinement, an experiment was performed. Fourteen specimens were tested. The test results showed that the internal Confinement existed and made the concrete in the state of triaxial Confinement.
Huanjun Jiang - One of the best experts on this subject based on the ideXlab platform.
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Confinement Effect of Concrete-Filled Steel Tube Columns With Infill Concrete of Different Strength Grades
Frontiers Media S.A., 2019Co-Authors: Siqi Lin, Huanjun JiangAbstract:Concrete-filled steel tube (CFST) columns are increasingly used in composite construction. Under axial compression, the steel tube will sustain partial axial force and meanwhile provides the Confinement to the infill concrete. The high axial strength capacity of CFST columns is largely related to the Confinement provided by the steel tube. Extensive studies on CFST columns have been conducted. Nevertheless, how to quantify the efficiency of Confinement effect in CFST columns using concrete with different strength grades is still missing. To address this issue, a series of compressive loading tests on CFST columns were conducted in present study. The variable parameters studied include concrete strength and diameter-to-thickness ratio of the steel tube. Six CFST stub columns in total were designed and tested under uniaxial compression. Axial strength, stress state in the steel tube, confined concrete strength and confining pressure acting on the infill concrete were carefully investigated. Test results show that the Confinement factor (defined as the ratio of the nominal strength of empty steel tube to that of the unconfined concrete) is the most dominant factor influencing the Confinement effect, and a larger Confinement factor gives higher Confinement effect. The low-strength concrete exhibits better performance of ductility and Confinement compared with the high-strength concrete. The index of equivalent confining pressure was used to quantify the level of passive Confinement provided by the steel tube in CFST columns. Based on the test results, a method to quickly quantify the confining pressure provided by the steel tube was proposed
Muatafa Esat Tezcan - One of the best experts on this subject based on the ideXlab platform.
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the relationship between chronotype sleep and autism symptom severity in children with asd in covid 19 home Confinement period
Chronobiology International, 2020Co-Authors: Serhat Turkoglu, Halit Necmi Ucar, Fatih Hilmi Cetin, Hasan Ali Guler, Muatafa Esat TezcanAbstract:This study aimed to investigate the relationship between chronotype preference/sleep problems and symptom severity of children with Autism spectrum disorder (ASD) during the Confinement and social isolation of the COVID-19 outbreak. This study included 46 drug-naive children aged 4-17 y diagnosed with ASD. The Autism Behavior Checklist (AuBC), Children's Sleep Habits Questionnaire (CSHQ), and Children's chronotype questionnaire (CCQ) were filled out before and at the end of the COVID-19 mandated home Confinement by the children's parents. Children with ASD during the home Confinement reported higher chronotype scores, i.e., eveningness chronotype, sleep problems, and autism symptom scores compared to the normal non-hone Confinement state. The chronotype score and sleep problems of children with ASD during the home Confinement period varied according to the AuBC score. The sleep problems of the children with ASD during the home Confinement period mediated the relationship between chronotype score and severity of autism symptoms. It is essential to validate the role of the mediator effect of sleep problems and chronotype in larger samples of children with ASD with restricted to home Confinement during the pandemic period. If sleep problems can be controlled with parental education, pharmacotherapy, and psychotherapeutic interventions, the impact on children with ASD of home Confinement can be reduced.
