Numerical Study of Bearing Strength of Infilled Concrete in Large Diameter CFST Column Reinforced by Shear Stoppers

Ensuring an adequate bond between the steel tube and infilled concrete interface plays an essential role in achieving composite action for concrete-filled steel tubular (CFST) columns. Thus, this study proposes a new type of large diameter CFST column where the steel tube is reinforced by shear stoppers. The bearing strength of the infilled concrete is the decisive factor in evaluating the overall working efficiency between infilled concrete and steel tube. In this paper, we use nonlinear finite element analysis (NFEA) to investigate the bearing strength of the infilled concrete concerning the ratio of the steel tube’s diameter to its thickness (D/t), the number of shear stoppers N, the height of the shear stopper hb, and the concrete compressive strength (CCS) fc′. Our results show that the influencing factors on the bearing strength of the infilled concrete were arranged in descending order as follows: the number of shear stoppers, the height of shear stopper, the CCS, and the D/t ratio. We also analyze and highlight some significant parameters related to the bearing strength of infilled concrete

In the interest of public safety: rapid response to the COVID-19 epidemic in Vietnam

We describe the status of the COVID-19 epidemic in Vietnam, major response successes, factors that prompted implementation of certain public health actions, and the impact of these actions. In addition, information for three case studies is reported, with crucial learnings to inform future response. Findings from this study suggest that as early as 20 January 2020, Vietnam held a national risk assessment, established a national COVID-19 Response Plan and Technical Treatment and Care Guidelines, and prepared public health laboratories to accurately diagnose cases and hospitals to effectively treat patients. The first COVID-19 case was detected on 23 January. As of 30 September, there had been three waves of the COVID-19 epidemic totalling 1095 cases, and resulting in 35 deaths all among people with underlying health conditions. Evidence of potential transmission of SARS-CoV-2 from a commercial passenger flight inbound to Vietnam was reported. This study also highlights the importance of early technical preparedness, strong political commitment, multisectoral and multilevel efforts, increased resourcing and coordination towards an effective COVID-19 response. Controlling outbreaks in settings, such as crowded public places (bars and hospitals), within certain villages and over cities, required early detection, aggressive trace-test-quarantine efforts, a geographically extensive lockdown area and an adoption of several non-pharmaceutical interventions. Many low-income and middle-income countries have experienced their second or third wave of the COVID-19 epidemic, and they can learn from Vietnam’s response across the three epidemic waves. Swift governmental action, strict border control measures, effective communication of health promotion measures, widespread community engagement, expanded testing capacity and effective social measures to slow the spread of SARS-CoV-2, are highly important in these locations

General approach for parameterization of the inverse dynamic equation for industrial robot and 5-axis CNC machine

In practice, using the 5-axis CNC machines and industrial welding robots for fabricating more and more complex mechanical parts is an increasing demand. In this context, the tooltip of the machines/robots is usually required to move along a complex toolpath represented by a parametric equation such as Bezier, Spline or NURBS. Hence, computation of the inverse kinematics and dynamics e.g. velocities, accelerations, jerks and applied torques/forces in the joint space of a machine/robot when the tooltip tracks such as high curvature parametric curve is challenging. Therefore, this paper presents a general approach for the parameterization of the kinematic and dynamic equations of the machine/robot. By using the proposed method, the kinematics and dynamics model of a machine/robot can be formulated in the parametric domain, which is advantageous and applicable for the dynamic analysis of the 5-axis CNC machine/robot and other purposes

Three-Photon Absorption Induced Photoluminescence in Organo-Lead Mixed Halide Perovskites

International audienc

Effect of calophyllolide on myeloperoxidase (MPO) activity.

<p>All mice were sacrificed on day 1 and day 5 post-operation, and skin tissue samples were collected to assess MPO activity (n = 3 mice per group per experiment). Data are represented as mean ± SEM and compared by one-way ANOVA. *** P<0.001.</p

Effect of calophyllolide (CP) on acceleration of wound closure.

<p>Effect of calophyllolide (CP) on acceleration of wound closure.</p

Effect of calophyllolide on HaCaT and RAW264.7 cell viability.

<p>HPLC chromatograms of the isolated calophyollide <b>(A)</b> and standard control <b>(B)</b>. This compound was recorded at 233 nm, and its retention time is 36.6 min. <b>(C)</b> No effect of CP on the viability of both HaCaT and murine macrophage RAW264.7 cells after 24 h treatment.</p

Anti-inflammatory and wound healing activities of calophyllolide isolated from <i>Calophyllum inophyllum</i> Linn

<div><p>Due to the high-cost and limitations of current wound healing treatments, the search for alternative approaches or drugs, particularly from medicinal plants, is of key importance. In this study, we report anti-inflammatory and wound healing activities of the major calophyllolide (CP) compound isolated from <i>Calophyllum inophyllum</i> Linn. The results showed that CP had no effect on HaCaT cell viability over a range of concentrations. CP reduced fibrosis formation and effectively promoted wound closure in mouse model without causing body weight loss. The underlying molecular mechanisms of wound repair by CP was investigated. CP markedly reduced MPO activity, and increased M2 macrophage skewing, as shown by up-regulation of M2-related gene expression, which is beneficial to the wound healing process. CP treatment prevented a prolonged inflammatory process by down-regulation of the pro-inflammatory cytokines—IL-1β, IL-6, TNF-α, but up-regulation of the anti-inflammatory cytokine, IL-10. This study is the first to indicate a plausible role for CP in accelerating the process of wound healing through anti-inflammatory activity mechanisms, namely, by regulation of inflammatory cytokines, reduction in MPO, and switching of macrophages to an M2 phenotype. These findings may enable the utilization of CP as a potent therapeutic for cutaneous wound healing.</p></div

Attenuation of inflammatory cytokines expression by calophyllolide.

<p>Serum levels of (<b>A</b>) IL-1β, (<b>B</b>) IL-6, (<b>C</b>) TNF-α, and (<b>D</b>) IL-10. Data are represented as mean ± SEM and compared by one-way ANOVA (n = 3 mice per group per experiment). * P<0.05, ** P<0.01, *** P<0.001.</p

Histological and quantitative analyses of the cutaneous wound healing of calophyllolide.

<p>Mice were daily treated with CP (6 mg/animal) and PI (100 mg/animal) until enthanasia. <b>(A)</b> Histological observation of collagen on wound healing at day 14 by Masson’s Trichrome staining. Reduction of collagenous scar (arrow head) in CP-treated group compared to vehicle- and PI-treated groups. Arrows indicate wound site with scale bar = 1cm. <b>(B)</b> Representative graph of semi-quantitative collagen content at day 10 and day 14 (n = 3–4 animals per group per experiment). Data are represented as mean ± SEM and compared by one-way ANOVA.</p