A model for pushover analysis of confined masonry structures : implementation and validation

Confined masonry (CM) is a typical building technique in Latin American countries. This technique, due to its simplicity of construction and similarity with traditional practices of reinforced concrete building, presents a potential of use in European regions with moderate-to-high seismicity. However, most of the procedures for seismic design in codes for Latin America are force-based, which appears to be inadequate due to the high dissipative response observed for CM. This paper presents a simplified numerical-analytical approach to model CM structures using pushover analysis, aiming to apply performance-based design procedures. First, a data mining process is performed on a database of experimental results collected from lateral tests on CM walls to adjust prediction models for the wall shear strength and to determine the input relevance through a sensitivity analysis. Then, an analytical model of CM structures for pushover analysis is proposed with basis on a wide-column approach that employs an adaptive shear load-displacement constitutive relation. The proposed method is compared with a discrete element model that represents explicitly the confinements-masonry interaction, against the experimental results obtained in a quasi-static test of a full-scale tridimensional CM structure. The accuracy of the predictions from both methods is very satisfactory, allowing to capture the base shear-displacement envelope and also the damage patterns of the structure, thus, demonstrating the ability of the methods to be used in performance-based seismic assessment and design of CM buildings.The first author acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the Ph.D. Grant SFRH/BD/41221/2007

Increased HIV-1 transcriptional activity and infectious burden in peripheral blood and gut-associated CD4+ T cells expressing CD30

HIV-1-infected cells persist indefinitely despite the use of combination antiretroviral therapy (ART), and novel therapeutic strategies to target and purge residual infected cells in individuals on ART are urgently needed. Here, we demonstrate that CD4+ T cell-associated HIV-1 RNA is often highly enriched in cells expressing CD30, and that cells expressing this marker considerably contribute to the total pool of transcriptionally active CD4+ lymphocytes in individuals on suppressive ART. Using in situ RNA hybridization studies, we show co-localization of CD30 with HIV-1 transcriptional activity in gut-associated lymphoid tissues. We also demonstrate that ex vivo treatment with brentuximab vedotin, an antibody-drug conjugate (ADC) that targets CD30, significantly reduces the total amount of HIV-1 DNA in peripheral blood mononuclear cells obtained from infected, ART-suppressed individuals. Finally, we observed that an HIV-1-infected individual, who received repeated brentuximab vedotin infusions for lymphoma, had no detectable virus in peripheral blood mononuclear cells. Overall, CD30 may be a marker of residual, transcriptionally active HIV-1 infected cells in the setting of suppressive ART. Given that CD30 is only expressed on a small number of total mononuclear cells, it is a potential therapeutic target of persistent HIV-1 infection

Role of fumed silica on ion conduction and rheology in nanocomposite polymeric electrolytes

The electrochemical, rheological, calorimetric, spectroscopic and morphological investigations have been used to examine poly(methyl methacrylate), PMMA based electrolytes dispersed with nano-sized fumed silica (SiO2). The observed ionic conductivity was one of the highest and is of the order similar to mS/cm at ambient temperature which was studied as a function of concentration of fumed silica nano-particles. It was further found that the fumed silica acted as a passive filler and played a predominant role in controlling the rheological properties while ion transport properties were least effected. The differential calorimetry studies revealed single glass transition temperature pointing towards homogeneous nature of the composite polymeric electrolytes (CPEs). At an optimum concentration of fumed silica (2 wt%) the observed maximum conductivity and morphology was attributed to the presence of a strong network structure, while at a higher concentration the elastic behavior was more pronounced which impeded ion transport. This contention was supported by spectroscopic data

SARS-CoV-2 specific IgG antibodies among participants presenting to a voluntary testing facility in Srinagar, Kashmir

Background: The tide of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) pandemic has scoured the global community with India, from 30 January 2020 to 30 September 2021, reporting 33,739,980 confirmed cases and over 448,090 deaths from coronavirus disease (COVID-19). Serologic testing for SARS-CoV-2 infection among the general public will provide essential information regarding the risk of infection. So, the present study was conducted to provide relevant information on the proportion of people who hadexperienced either a recent or past infection. Methodology: A cross-sectional study was conducted among adults >18 years in the Department of Community Medicine, Government medical college, Srinagar. Blood samples of the participants were tested for the presence of SARS-CoV-2-specific IgG antibodies using a chemiluminescent microparticle immunoassay-based serologic test. Results: A total of 2,107 participants took part in the study. The overall unadjusted seroprevalence of IgG antibodies against SARS-CoV-2 in our study was 49%. The age-adjusted seroprevalence was 52%. Conclusion: The findings of the study suggested that not only a large proportion (49%) of the participants had been infected with COVID-19 infection but many were also susceptible to infection. Therefore, infection control measures still need to be followed properly

Heat Transfer Enhancement in Microchannel Flow: Presence of Microparticles in a Fluid

In the present study, a numerical model was developed for laminar flow in a microchannel with a suspension of microsized phase change material (PCM) particles. In the model, the carrier fluid and the particles are simultaneously present, and the mass, momentum, and energy equations are solved for both the fluid and particles. The particles are injected into the fluid at the inlet at a temperature equal to the temperature of the carrier fluid. A constant heat flux is applied at the bottom wall. The temperature distribution and pressure drop in the microchannel flow were predicted for lauric acid microparticles in water with volume fractions ranging from 0 to 8%. The particles show heat transfer enhancements by decreasing the temperature distribution in the working fluid by 39% in a 1 mm long channel. Meanwhile, particle blockage in the flow passage was found to have a negligible effect on pressure drop in the range of volume fractions studied. This work is a first step towards providing insight into increasing heat transfer rates with phase change-based microparticles for applications in microchannel cooling and solar thermal systems