Cement production gives rise to CO
2
emissions generated by the calcination of CaCO
3
and by the combustion of fossil fuels, being responsible for about 5% of the global CO
2
emissions. These ...emissions can be substantially reduced if cement replacement materials are used. In this paper two residual ashes that can be used as mineral additions are considered: sugar cane bagasse ash and rice husk ash. A case study of the construction of a dam with a blended material composed by cement and these two ashes is presented, indicating the potentiality of its use for civil engineering applications. The analyses were performed using experimental and numerical tools developed on the basis of a thermo-chemo-mechanical model. This model considers the coupling, within the theory of thermodynamics, of the several phenomena that intervene in the hydration process, namely, exothermicity, thermo-activation, chemo-plasticity, evolution of thermal and mechanical properties with the hydration reaction, which includes creep and relaxation.
This paper presents a data mining approach for modeling the adiabatic temperature rise during concrete hydration. The model was developed based on experimental data obtained in the last thirty years ...for several mass concrete constructions in Brazil, including some of the hugest hydroelectric power plants in operation in the world. The input of the model is a variable data set corresponding to the binder physical and chemical properties and concrete mixture proportions. The output is a set of three parameters that determine a function which is capable to describe the adiabatic temperature rise during concrete hydration. The comparison between experimental data and modeling results shows the accuracy of the proposed approach and that data mining is a potential tool to predict thermal stresses in the design of massive concrete structures.
In regions of very high dark matter density such as the Galactic Centre, the capture and annihilation of WIMP dark matter by stars has the potential to significantly alter their evolution. We ...describe the dark stellar evolution code DarkStars, and present a series of detailed grids of WIMP-influenced stellar models for main-sequence stars. We describe the changes in stellar structure and main-sequence evolution which occur as a function of the rate of energy injection by WIMPs, for masses of 0.3–2.0 M⊙ and metallicities Z= 0.0003–0.02. We show what rates of energy injection can be obtained using realistic orbital parameters for stars at the Galactic Centre, including detailed consideration of the velocity and density profiles of dark matter. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits. If there is a spike of dark matter induced by the supermassive black hole at the Galactic Centre, single solar mass stars following orbits with periods as long as 50 yr and eccentricities as low as 0.9 could be significantly affected. Binary systems with similar periods about the Galactic Centre could be affected on even less eccentric orbits. The most striking observational effect of this scenario would be the existence of a binary consisting of a low-mass protostar and a higher mass evolved star. The observation of low-mass stars and/or binaries on such orbits would either provide a detection of WIMP dark matter, or place stringent limits on the combination of the WIMP mass, spin-dependent nuclear-scattering cross-section, halo density and velocity distribution near the Galactic Centre. In some cases, the derived limits on the WIMP mass and spin-dependent nuclear-scattering cross-section would be of comparable sensitivity to current direct-detection experiments.
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of the spin-precession frequencies of stored ultracold neutrons and Hg199 atoms for an axion-induced oscillating ...electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range 10−24≤ma≤10−17eV . Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also improves on previous laboratory constraints on the axion coupling to nucleons by up to a factor of 40.
This paper reports an experimental study on the magnesium sulphate resistance of mortar specimens incorporating 0, 10 and 20% of metakaolin (MK). The evidence of the attack was evaluated through the ...content of calcium hydroxide (portlandite) and formation of magnesium hydroxide (brucite) by thermal analysis (thermogravimetric and derivative thermogravimetric analysis). The mechanical degradation of the mortar specimens was evaluated through splitting tensile tests after 200 days of exposition to the magnesium solution. The addition of metakaolin resulted in a reduction in the content of calcium hydroxide and in a smaller formation of brucite in comparison with reference mixture. A tensile strength loss of about 7% was observed for the metakaolin mortars submitted to the magnesium solution attack for 200 days.
Radion assisted gauge inflation Fairbairn, M.; Lopez Honorez, L.; Tytgat, M. H. G.
Physical review. D, Particles and fields,
05/2003, Letnik:
67, Številka:
10
Journal Article
Abstract
Background/Introduction
The prevalence of ischaemic heart disease is lower in women vs men in Canada. Studies have shown that women are more likely to be underdiagnosed and less likely to ...receive guideline-recommended treatments than men. Women receiving lipid-lowering therapies (LLTs) are also less likely to attain treatment goals vs men.
Purpose
We analysed use of LLTs and attainment of low-density lipoprotein cholesterol (LDL-C) treatment goals in a recent longitudinal cohort of patients with ASCVD with public drug coverage in Ontario to describe differences observed between female and male patients.
Methods
Patients ≥65 years with a primary ASCVD event/procedure between 1 Apr 2005 and 31 Mar 2016, treated with an LLT and with index and follow up LDL-C values were identified from claims data at the Institute for Clinical Evaluative Sciences data repository. Patients were assessed over a 1 year follow up period for LDL-C goal attainment (<2.0 mmol/L or 50% reduction from index LDL-C as per Canadian Cardiovascular Society Guidelines) and analysed by LLT category.
Results
143,302 patients with ASCVD ≥65 years on LLTs were identified of which 41% were female. A higher proportion of female vs male patients were prescribed low (3% vs 2%) and medium intensity statins (51% vs 44%) compared with high intensity statins (43% vs 52%). A higher proportion of women failed to attain LDL-C goal compared to men (33% vs 24%) (Figure). When analysed by low, moderate or high intensity statin, 65%, 35%, and 27% of female patients and 49%, 25% and 19% of male patients failed to attain LDL-C goal at follow up.
Conclusions
In this retrospective study, women with a diagnosis of ASCVD were more frequently treated with low/moderate intensity statins whereas men were more frequently treated with high intensity statins. Approximately 2 of 3 women and 3 of 4 men receiving statin treatment attained LDL-C goal during the 1-year follow up period. Overall, there appear to be treatment differences between female and male patients with ASCVD, with males receiving higher intensity statin therapy and attaining LDL-C goal more frequently. Further research is needed to determine why these discrepancies exist.
This study made use of de-identified data from the ICES Data Repository, which is managed by the Institute for Clinical Evaluative Sciences with support from its funders and partners: Canada's Strategy for Patient-Oriented Research (SPOR), the Ontario SPOR Support Unit, the Canadian Institutes of Health Research and the Government of Ontario. The opinions, results and conclusions reported are those of the authors. No endorsement by ICES or any of its funders or partners is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI.
Figure 1
Funding Acknowledgement
Type of funding source: Private company. Main funding source(s): Amgen Canada Inc
Abstract
Background/Introduction
Limited real-world data are available on attainment of low-density lipoprotein cholesterol (LDL-C) treatment goals in patients with atherosclerotic cardiovascular ...disease (ASCVD) in Canada.
Purpose
A retrospective observational study was conducted to describe types of ASCVD events/procedures, time between events and use of lipid lowering treatment (LLT) in patients who did not achieve LDL-C goal.
Methods
Patients in Ontario ≥65 years with a primary ASCVD event/procedure between 1 Apr 2005 and 31 Mar 2016, treated with an LLT and with index and follow up LDL-C values were identified from claims data at the Institute for Clinical Evaluative Sciences data repository. Patients were assessed over a 1-year follow up period for LDL-C goal attainment (<2.0 mmol/L or 50% reduction from index LDL-C) and analysed by LLT and by index event type.
Results
Overall, 28% of 143,302 patients ≥65 years on LLT failed to attain LDL-C goal at follow up (Figure). The proportion of patients failing to achieve LDL-C goal decreased from 35% to 22% over the 11-year study period. Mean time between index and follow up LDL-C (based on lowest score >2 weeks and up to 1 year after index LDL-C) was 203±97 days. When analysed by low-, moderate- or high-intensity statin, 57%, 30%, and 22% of patients failed to achieve LDL-C goal at follow up, respectively.
Conclusions
In this study, more than 1 in 4 patients with ASCVD in Ontario failed to achieve guideline recommended LDL-C goal despite treatment. In particular, ∼1 in 3 patients with cerebral and peripheral arterial disease were not at goal. An opportunity exists to better manage these high risk ASCVD patients with further statin intensification and additional LLTs
This study made use of de-identified data from the ICES Data Repository, which is managed by the Institute for Clinical Evaluative Sciences with support from its funders and partners: Canada's Strategy for Patient-Oriented Research (SPOR), the Ontario SPOR Support Unit, the Canadian Institutes of Health Research and the Government of Ontario. The opinions, results and conclusions reported are those of the authors. No endorsement by ICES or any of its funders or partners is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI
Funding Acknowledgement
Type of funding source: Private company. Main funding source(s): Amgen Canada Inc.
Astrophysical sources of energetic gamma rays provide the right conditions for maximal mixing between (pseudo)scalar (axion-like) particles and photons if their coupling is strong enough. This is ...independent of whether or not the axion interaction is standard at all energies or becomes suppressed in the extreme conditions of the stellar interior. The flux of such particles through the Earth could be observed using a metre long, Tesla strength superconducting solenoid. The rate of events in CAST caused by axions from the Crab pulsar is also estimated.
Inflation from a tachyon fluid? Fairbairn, Malcolm; Tytgat, Michel H.G
Physics letters. B,
10/2002, Letnik:
546, Številka:
1-2
Journal Article
Recenzirano
Odprti dostop
Motivated by recent works of Sen hep-th/0203211, hep-th/0203265 and Gibbons hep-th/0204008, we study the evolution of a flat and homogeneous universe dominated by tachyon matter. In particular, we ...analyze the necessary conditions for inflation in the early roll of a single tachyon field. Comparison with string theory reveals that the potential is too steep to explain the fluctuations in the CMBR. We suggest a scenario based on the simultaneous decay of many branes and comment on the issue of reheating of the universe after tachyon rolling.
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