78 research outputs found

    Prediction Of Strength Properties Of Geopolymer Concrete Using Artificial Intelligence Techniques

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    Several studies have successfully used fly-ash (FA)-like waste material for the manufacturing of geopolymer concrete (GPC). This study uses gene expression programming (GEP), a type of soft computing approach, to produce an empirical equation that estimates the compressive strength fc0 of GPC using FA. Through a thorough analysis of the published research, a consistent, large, and trustworthy data set is assembled in order to develop a model. 298 fc0 experimental outcomes make up the collected data set. The following are considered explanatory variables: the amount of extra water added as percent FA (%EW), the percentage of plasticizer (%P), the initial curing temperature (T), the specimen's age (A), the curing duration (t), the ratio of fine aggregate to total aggregate (F/AG), the percentage of total aggregate by volume (%AG), the molarity of the NaOH solution, the activator or alkali to FA ratio (AL/FA), the ratio of sodium oxide (Na2O) to water (N/W) for preparing Na2SiO3 solution, and the ratio of Na2SiO3 to NaOH (Ns/No). An empirical GEP equation is put forth to calculate the fc0 of GPC using FA. The suggested model's precision, applicability, and forecasting capacity were assessed using parametric analysis, statistical verification, and a comparison with both linear and non-linear regression equations

    A laboratory facility to study gas-aerosol-cloud interactions in a turbulent environment: The Π Chamber

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    A detailed understanding of interactions of aerosols, cloud droplets/ice crystals, and trace gases within the atmosphere is of prime importance for an accurate understanding of Earth’s weather and climate. One aspect that remains especially vexing is that clouds are ubiquitously turbulent, and therefore thermodynamic and compositional variables, such as water vapor supersaturation, fluctuate in space and time. With these problems in mind, a multiphase, turbulent reaction chamber—called the Π chamber because of the internal volume of 3.14 m3 with the cylindrical insert installed—has been developed. It is capable of pressures ranging from 1,000 to –60 hPa and can sustain temperatures of –55° to 55°C, thereby spanning much of the range of tropospheric clouds. To control the relative humidity in the chamber, it can be operated with a stable, unstable, or neutral temperature difference between the top and bottom surfaces, with or without expansion. A negative temperature difference induces turbulent Rayleigh–Bénard convection and associated supersaturation generation through isobaric mixing. Supporting instrumentation includes a suite of aerosol generation and characterization techniques; temperature, pressure, and humidity sensors; and a phase Doppler interferometer. Initial characterization experiments demonstrate the ability to sustain steady-state turbulent cloud conditions for times greater than 1 day, with droplet diameters typically in the range of 5–40 µm. Typical turbulence has root-mean-square velocity fluctuations on the order of 10 cm s–1 and kinetic energy dissipation rates of 1 × 10–3 W kg–1

    Animal welfare attitudes: Effects of gender and diet in university samples from 22 countries

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    Animal Welfare Attitudes (AWA) are defined as human attitudes towards the welfare of animals in different dimensions and settings. Demographic factors, such as age and gender are associated with AWA. The aim of this study was to assess gender differences among university students in a large convenience sample from twenty-two nations in AWA. A total of 7914 people participated in the study (5155 women, 2711 men, 48 diverse). Participants completed a questionnaire that collected demographic data, typical diet and responses to the Composite Respect for Animals Scale Short version (CRAS-S). In addition, we used a measure of gender empowerment from the Human Development Report. The largest variance in AWA was explained by diet, followed by country and gender. In terms of diet, 6385 participants reported to be omnivores, 296 as pescatarian, 637 ate a vegetarian diet and 434 were vegans (n = 162 without answer). Diet was related with CRAS-S scores; people with a vegan diet scored higher in AWA than omnivores. Women scored significantly higher on AWA than men. Furthermore, gender differences in AWA increased as gender inequality decreased

    Introducing RFID at Middlesex University Learning Resources

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    Purpose - to desribe the first year of the implementation of the RFID in Middlesex University Learning Resources Design/Methodology/Approach - The technology is explained in detail to set the scene. Information on the implementation is presented in chronological order. Findings - problems which would generally be applicable to other institutions in these early days of the use fo RFID in libraries are pointed out. Practical Implications - it is possible to implement RFID without too much lead time, though had longer been available some aspects would have gone more smoothly

    Avifauna of wetlands of Amravati region, Maharashtra, India

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    This paper presents our observations, between March 2006 and March 2008, on the birdlife of the wetlands of the Amravati region, Maharashtra. In total, 97 species of birds, including Oriental White Ibis, a near-threatened species were recorded. Among the wetlands, Wadali Lake records the highest number of bird species. Current threats to these wetlands are also briefly discussed

    Oculosporidiosis

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