30 research outputs found
Experimental study of formwork tightness as a function of rheological properties of SCC
Several studies relating formwork pressure to rheology exist, however the relationship between rheology and leakage through formwork joints remains to be investigated. In practice, standard documents are used to define formwork tightness requirements, typically using a qualitative approach. To try bridge this gap in knowledge, we developed a test set-up to study tightness of formwork joints under pressure as a function of varying rheological properties. Coupled with standard rheology tests, this new test set-up provides means of linking flow rate, formwork pressure, flow area, and the rheological properties. The study seeks to provide insight on measurable governing parameters and thus inform formwork tightness requirements in a more quantifiable manner.
This paper presents a test set-up designed to study the flow of fresh paste through small openings. It highlights a preliminary study on the pressure-driven flow of limestone paste through a bottom orifice in a cylindrical container. While this new device may not be directly representative of the actual conditions in formwork, it provides a good base for a fundamental study that can then be extrapolated to a more representative test operation. Preliminary results show a linear relationship between the flow rate and the applied pressure. The results also show that increasing the flow area by a factor of 2.33 had a higher impact than an increase in yield stress and viscosity by a factor of 2.54 and 3.80 respectively. However, more tests need to be carried out to obtain clear trends
Evolution of Primordial Black Hole Mass Spectrum in Brans-Dicke Theory
We investigate the evolution of primordial black hole mass spectrum by
including both accretion of radiation and Hawking evaporation within
Brans-Dicke cosmology in radiation, matter and vacuum-dominated eras. We also
consider the effect of evaporation of primordial black holes on the expansion
dynamics of the universe. The analytic solutions describing the energy density
of the black holes in equilibrium with radiation are presented. We demonstrate
that these solutions act as attractors for the system ensuring stability for
both linear and nonlinear situations. We show, however, that inclusion of
accretion of radiation delays the onset of this equilibrium in all radiation,
matter and vacuum-dominated eras.Comment: 18 pages, one figur
Brans-Dicke Theory and primordial black holes in Early Matter-Dominated Era
We show that primordial black holes can be formed in the matter-dominated era
with gravity described by the Brans-Dicke theory. Considering an early
matter-dominated era between inflation and reheating, we found that the
primordial black holes formed during that era evaporate at a quicker than those
of early radiation-dominated era. Thus, in comparison with latter case, less
number of primordial black holes could exist today. Again the constraints on
primordial black hole formation tend towards the larger value than their
radiation-dominated era counterparts indicating a significant enhancement in
the formation of primordial black holes during the matter-dominaed era.Comment: 9 page
Cytokines and Inflammatory Mediators [30-39]: 30. The LPS Stimulated Production of Interleukin-10 is not Associated with -819C/T and -592C/A Promoter Polymorphisms in Healthy Indian Subjects
Background: Interleukin-10 is a pivotal immunoregulatory cytokine with pleiotropic effects on the immune system. IL-10 promoter polymorphisms have been associated with disease susceptibility and the ability to secrete IL-10 in vitro. We suspected that the association of the widely studied -819C/T and -592C/A polymorphisms with the IL-10 production might vary between ethnic groups. Therefore, we examined the association of -819 C/T and -592 C/A promoter polymorphisms with in vitro LPS stimulated secretion of IL-10 in normal healthy Indian volunteers. Methods: Peripheral blood was collected from 103 healthy volunteers and diluted whole blood cultures were set up with 100 ng/ml of LPS as stimulant: supernatant was collected at 24âh and IL-10 levels were assayed by ELISA. Genotyping was done for -819C/T polymorphism in 101 individuals and -592C/A polymorphism in 68 individuals by polymerase chain reaction followed by RFLP. The differences in IL-10 production between the genotypes were analysed by ANOVA. Results: There were 30, 47 and 24 individuals with the CC, CT and TT genotypes with a minor allele (T) frequency of 47% for the -819C/T polymorphism. The CC and TT genotypes at position -819 were strongly associated with CC and AA genotypes at -592 position suggestive of strong linkage disequilibrium. There was no association between the -819 genotype and the in vitro LPS stimulated IL-10 levels. Conclusions: The -819C/T and the -592 C/A polymorphisms of the IL-10 promoter region are not significantly associated with LPS stimulated IL-10 production healthy Indian subjects. Disclosure statement: All authors have declared no conflicts of interes
Wound curriculum for student nurses ::European Qualification Framework Level 4
In recent years, the care of people with chronic wounds has made enormous progress throughout Europe. However, aging populations, more complex wounds and advanced diagnostics are big challenges, especially because more people with chronic wounds are treated in their own homes. Bringing existing evidence-based and best practice knowledge to all nurses is a key objective of the European Wound Management Association (EWMA). The EWMA has previously published curricula for professional* nurse education intended for use in post-registration qualification in wound management on Levels 5â7 of the European Qualifications Framework (EQF). The aim of these curricula is to support a common approach to pre- and post-registration qualification in wound management for nurses across Europe. The curricula were developed by working groups representing different European countries and providers of education. However, as vocational qualifications throughout Europe are not uniform and pre-registration curricula may differ, there has been an unmet need to develop a curriculum covering pre-registration nurse education, to provide a starting point for increased and standardised education in wound care. This curriculum presents a framework and key content on skin integrity and wound care that is recommended for inclusion in student nurse curricula (general nurse education). In most European countries, this curriculum corresponds with the European Qualification Framework (EQF) Level 4. In combination, the full series of EWMA curricula can thus be adapted to meet the competencies expected at Level 4, progressing into Levels 5, 6 or 7
Climate change scenarios and sea level rise estimates for the California 2008 Climate Change Scenarios Assessment
For the 2008 California Climate Change Assessment, to further investigate possible future climate changes in California, a set of 12 climate change model simulations was selected and evaluated. From the Intergovernmental Panel on Climate Change Fourth Assessment activities projections, simulations of twenty-first century climates under a B1 (low emissions) and an A2 (a medium-high emissions) emissions scenarios were evaluated. Six climate models were chosen. These emission scenarios and climate simulations are not âpredictions,â but rather are possible scenarios of plausible climate sequences that might affect California in the next century. Temperatures over California warm significantly during the twenty-first century in each simulation. Also the rise in global sea level, and by extension the rise of sea level along the California coast, increases. Along with this, there are marked increases in the frequency, magnitude, and duration of heat waves and sea level rise extremes. There is quite a strong inclination for higher warming in summer than winter and greater warming inland than along the coast. In several of the simulations there is a tendency for drier conditions to develop during mid-and late-twenty-first century in Central and Southern California, and along with this, a decline in winter wave energy along the California coast
Regional Cooperation for Development: A Review and Critique of the Southern African Development Coordination Conference
Subadventitial crossing and crushing to recanalize in-stent chronic total occlusions: A multicenter registry
BACKGROUND Crossing chronic total occlusions (CTOs) due to instent restenosis (ISR) can sometimes be achieved with subadventitial crossing and crushing (SC+C) of the occluded stent, when conventional approaches have failed. We aimed at evaluating the outcomes of this technique. METHODS We examined the acute and follow-up outcomes of ISR-CTO percutaneous coronary intervention (PCI) performed at 14 centers between July 2011 and June 2017. Target-vessel failure (TVF) was defined as a composite of cardiac death, target-vessel myocardial infarction (TV-MI), and ischemia-driven target-vessel revascularization (TVR). RESULTS A totalof 422 in-stent CTO PCIs were performed during the study period, of which 32 (7.6%) were recanalized with SC+C. Class III-IV angina was present in 50% of patients. The most frequent CTO vessel was the right coronary artery (72%), and mean J-CTO score was 3.1±0.9. SC+C was performed after failure of other crossing techniques in all but 2 patients. The CrossBoss catheter was used in 38%. SC+C was antegrade in 53%, and retrograde in 47%. Part of the occluded stent was crushed in 37%, while the whole stent was crushed in 63%. Intravascular imaging was performed in 59%. Total newly implanted stent length was 106±35 mm, contrast volume was 305±144 ml, and fluoroscopy time was 79±45 min. One patient (3.1%) suffered tamponade. Angiographic followup was performed in 10/32 patients at amean of 148±123 days: The stents were patent in 6 cases, 1 had mild ISR, and 3 had severe ISR at the site of SC+C. Clinical follow-up was available for 29/32 patients for amean of 388±303 days. The incidence of TVF was 20.7% (n=6), including cardiac death 3.4% (n=1, unrelated to SC+C), TV-MI 3.4% (n=1, due to stent thrombosis proximal to the SC+C site), and TVR 20.7% (n=6). CONCLUSION This is the first systematic study of SC+C for treating CTOs due to ISR. This technique is rarely performed, usually as last resort, torecanalize complex occlusions. SC+C is associated with favorable acute and mid-term outcomes, but given the small sample size of our study additional research is warranted