214 research outputs found

    Feasibility study of high volume slag as cement replacement for sustainable structural lightweight oil palm shell concrete

    Get PDF
    This paper presents a study on the use of high volume slag as a cement replacement material, and waste oil palm shell (OPS) as a lightweight aggregate to produce a sustainable lightweight concrete (LWC). In order to establish the feasibility of such concrete for structural purposes, the first part of the paper deals with the investigation of the mechanical and bond properties of OPS concrete (OPSC) with varying slag content. The results showed that even though an increase in the slag content led to the reduction in the strength, the OPSC with slag as a 60 cement replacement material exhibited compressive and splitting tensile strengths of 25 and 2.3 MPa, respectively, which exceeded the minimum stipulated strength required for structural LWC. In addition, the use of 60 slag in OPSC showed significant benefits in terms of the reduced cement consumption with improvement in the strength efficiency by almost 2-fold compared to that without slag. On the other hand, it was found that the slag content, albeit as high as a 60 cement replacement level, did not show any significant adverse effects on the normalized bond strength, failure mode, bond strength-slip curve and slip at the ultimate bond strength of the OPSC. To further justify the suitability of the OSPC for structural application, the second part of the paper focuses on the experimental investigation of the flexural behaviour of the actual full-scale reinforced concrete beams. From the flexural tests, it was observed that there were no negative effects on the ultimate moment capacity, failure mode and moment-deflection behaviour of the reinforced concrete beams upon cement replacement with up to 60 slag. Therefore, the utilization of high volume slag-lightweight OPSC could be recommended for actual structural purposes. (C) 2014 Elsevier Ltd. All rights reserved

    Exclusive electroproduction of K+ Lambda and K+ Sigma^0 final states at Q^2 = 0.030-0.055 (GeV/c)^2

    Get PDF
    Cross section measurements of the exclusive p(e,e'K+)Lambda,Sigma^0 electroproduction reactions have been performed at the Mainz Microtron MAMI in the A1 spectrometer facility using for the first time the Kaos spectrometer for kaon detection. These processes were studied in a kinematical region not covered by any previous experiment. The nucleon was probed in its third resonance region with virtual photons of low four-momenta, Q^2= 0.030-0.055 (GeV/c)^2. The MAMI data indicate a smooth transition in Q^2 from photoproduction to electroproduction cross sections. Comparison with predictions of effective Lagrangian models based on the isobar approach reveal that strong longitudinal couplings of the virtual photon to the N* resonances can be excluded from these models.Comment: 16 pages, 7 figure

    Are online support groups always beneficial? A qualitative exploration of the empowering and disempowering processes of participation within HIV/AIDS-related online support groups

    Get PDF
    BACKGROUND: Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is one of the leading concerns in healthcare. Individuals living with HIV/AIDS are often confronted with tremendous physical and psychosocial challenges. Online support groups can provide a valuable source of information, advice and support, and a medium through which individuals living with HIV/AIDS can interact with each other and share their experiences. However, very little is known about how online support group might promote empowerment and the potential disadvantages associated with online support group use among individuals living with HIV/AIDS. OBJECTIVES: The present study explored the potential empowering and disempowering processes, and empowering outcomes of online support group use among individuals with HIV/AIDS. DESIGN, SETTINGS, PARTICIPANTS: A total of 115 HIV-positive online support group members were recruited from HIV-related online support groups. They completed an online survey exploring their experiences of online support group use. RESULTS: Thematic analysis revealed six empowering processes arising from use of online support groups: exchanging information, sharing experiences, connecting to others, encountering emotional support, finding recognition and understanding, and helping others. Six empowering outcomes were identified: increased optimism, emotional well-being, social well-being, being better informed, improved disease management, and feeling confident in the relationship with physicians. Potentially disempowering processes were also identified which included: being unable to connect physically, inappropriate behaviour online, declining real life relationships, and information overload and misinformation. CONCLUSION: Findings suggest ways through which individuals with HIV/AIDS may be empowered although some problematic features specific to the online context may also be present

    Definition and Characteristics of Behavioral Medicine, and Main Tasks and Goals of the International Society of Behavioral Medicine—an International Delphi Study

    Get PDF
    © 2020, The Author(s). Background: In the past decades, behavioral medicine has attained global recognition. Due to its global reach, a critical need has emerged to consider whether the original definition of behavioral medicine is still valid, comprehensive, and inclusive, and to reconsider the main tasks and goals of the International Society of Behavioral Medicine (ISBM), as the umbrella organization in the field. The purpose of the present study was to (i) update the definition and scope of behavioral medicine and its defining characteristics; and (ii) develop a proposal on ISBM’s main tasks and goals. Method: Our study used the Delphi method. A core group prepared a discussion paper. An international Delphi panel rated questions and provided comments. The panel intended to reach an a priori defined level of consensus (i.e., 70%). Results: The international panel reached consensus on an updated definition and scope of behavioral medicine as a field of research and practice that builds on collaboration among multiple disciplines. These disciplines are concerned with development and application of behavioral and biomedical evidence across the disease continuum in clinical and public health domains. Consensus was reached on a proposal for ISBM’s main tasks and goals focused on supporting communication and collaboration across disciplines and participating organizations; stimulating research, education, and practice; and supporting individuals and organizations in the field. Conclusion: The consensus on definition and scope of behavioral medicine and ISBM’s tasks and goals provides a foundational step toward achieving these goals

    Does surrounding greenness moderate the relationship between apparent temperature and physical activity? Findings from the PHENOTYPE project

    Get PDF
    Background: Physical activity can be affected by both meteorological conditions and surrounding greenness, but few studies have evaluated the effects of these environmental factors on physical activity simultaneously. This multi-city comparative study aimed to assess the synergetic effects of apparent temperature and surrounding greenness on physical activity in four European cities. Specifically, we aimed to identify an interaction between surrounding greenness and apparent temperature in the effects on physical activity. Methods: Data were collected from 352 adult residents of Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands), and Kaunas (Lithuania) as part of the PHENOTYPE study. Participants wore a smartphone for seven consecutive days between May-December 2013 and provided additional sociodemographic survey data. Hourly average physical activity (Metabolic Equivalent of Task (MET)) and surrounding greenness (NDVI) were derived from the Calfit mobile application collecting accelerometer and location data. Hourly apparent temperature was calculated from temperature and relative humidity, which were obtained from local meteorological stations along with other meteorological covariates (rainfall, windspeed, and sky darkness). We assessed the interaction effects of apparent temperature and surrounding greenness on hourly physical activity for each city using linear mixed models, while adjusting for meteorological, demographic, and time-related variables. Results: We found significant interactions between apparent temperature and surrounding greenness on hourly physical activity in all four cities. Significant quadratic effects of apparent temperature were found in the highest level of surrounding greenness for Stoke-on-Trent and Doetinchem, with 4% decrease in median MET observed for a 10°C departure from optimal temperature (15.2°C and 14.6°C, respectively). On the other hand, significant linear effects were found for higher levels of surrounding greenness in Barcelona and Kaunas, whereby an increase of 10°C was associated with ∼4% increase in median MET. Conclusion: Apparent temperature and surrounding greenness interacted in the effect on hourly physical activity across the four European cities, with varying effect between cities. While quadratic effects of temperature suggest diminishing levels of physical activity in the highest greenness levels in cities of temperate climates, the variation in surrounding greenness between cities could be further explored, particularly by looking at indoor-outdoor locations. The study findings support the need for evidence-based physical activity promotion and urban design

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

    Get PDF
    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

    Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

    Get PDF
    [no abstract available
    corecore