Search results for "Pressure"
showing 10 items of 4493 documents
Aluminum tri-isopropoxide as an alternative precursor for atomic layer deposition of aluminum oxide thin films
2019
Due to the safety challenges associated with the use of trimethylaluminum as a metal precursor for the deposition of alumina, different chemicals have been investigated over the years to replace it. The authors have investigated the use of aluminum tri-isopropoxide (TIPA) as an alternative alkoxide precursor for the safe and cost-effective deposition of alumina. In this work, TIPA is used as a stable Al source for atomic layer deposition (ALD) of Al2O3 when different oxidizing agents including water, oxygen plasma, water plasma, and ozone are employed. The authors have explored the deposition of Al2O3 using TIPA in ALD systems operating in vacuum and atmospheric pressure conditions. For the…
Toward Sustainable PLA-Based Multilayer Complexes with Improved Barrier Properties
2019
Poly(lactic acid) or PLA is currently considered as one of the most promising substitutes of conventional plastics, with low environmental impact, especially for food packaging applications. Nevertheless, some drawbacks, such as high permeability to oxygen, are still limiting its industrial applications. The objective of this study was to highly increase the oxygen barrier performance of PLA without compromising its sustainable nature and following the principles of circular economy perspective. Coproducts coming from mill industries, such as wheat gluten proteins (WG), were used to produce PLA-WG-PLA multilayer complexes with improved barrier performance. Different technologies of industri…
New high-pressure phase and equation of state of Ce2Zr2O8
2012
In this paper we report a new high-pressure rhombohedral phase of Ce2Zr2O8 observed from high-pressure angle-dispersive x-ray diffraction and Raman spectroscopy studies up to nearly 12 GPa. The ambient-pressure cubic phase of Ce2Zr2O8 transforms to a rhombohedral structure beyond 5 GPa with a feeble distortion in the lattice. Pressure evolution of unit-cell volume showed a change in compressibility above 5 GPa. The unit-cell parameters of the high-pressure rhombohedral phase at 12.1 GPa are ah = 14.6791(3) {\AA}, ch = 17.9421(5) {\AA}, V = 3348.1(1) {\AA}3. The structure relation between the parent cubic (P2_13) and rhombohedral (P3_2) phases were obtained by group-subgroup relations. All t…
Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants
2017
Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher. Methods For this analysis, we pooled national, subnational, or community population-based studies that had measured blood pressure in adults aged 18 years and older. We used a Bayesian hierarchical model to estimate trends from 1975 to 2015 in mean systolic and mean diastolic blood pressure, and the prevalence of rai…
Numerical and Experimental Study of a Novel Concept for Hydraulically Controlled Negative Loads
2016
This paper presents a numerical and experimental investigation of a novel concept that eliminates oscillations in hydraulic systems containing a counterbalance valve in series with a pressure compensated flow supply. The concept utilizes a secondary circuit where a low-pass filtered value of the load pressure is generated and fed back to the compensator of the flow supply valve. The novel concept has been implemented on a single boom actuated by a cylinder. A nonlinear model of the system has been developed and an experimental verification shows good correspondence between the model and the real system. The model is used for a parameter study on the novel concept. From the study it is found…
Sigh in patients with acute hypoxemic respiratory failure and acute respiratory distress syndrome: the PROTECTION pilot randomized clinical trial
2021
Background: Sigh is a cyclic brief recruitment manoeuvre: previous physiological studies showed that its use could be an interesting addition to pressure support ventilation to improve lung elastance, decrease regional heterogeneity and increase release of surfactant. Research question: Is the clinical application of sigh during pressure support ventilation (PSV) feasible? Study design and methods: We conducted a multi-center non-inferiority randomized clinical trial on adult intubated patients with acute hypoxemic respiratory failure or acute respiratory distress syndrome undergoing PSV. Patients were randomized to the No Sigh group and treated by PSV alone, or to the Sigh group, treated b…
Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study (Intensive…
2021
The original version of this article unfortunately contained a mistake. The members of the ESICM Trials Group Collaborators were not shown in the article but only in the ESM. The full list of collaborators is shown below. The original article has been corrected.
Rhéologie et déformation du verre dans des conditions extrêmes
2018
Hardness measurements performed at room temperature have proven that glass can flow under elevated pressure. During industrial glass production processes, the actual distribution of stress components in the glass during scribing remains, to date, poorly quantified, and thus continues to be challenging to model numerically. To better quantify the viscous contribution to the rheology of glass, the effect of pressure on the viscosity and structural relaxation of glass, needs to be quantified experimentally by in situ deformation measurements.In this thesis, I performed experiments and models to study: (i) the volumetric relaxation of glass after high-pressure treatment above the glass transiti…
Pressure support ventilation + sigh in acute hypoxemic respiratory failure patients: Study protocol for a pilot randomized controlled trial, the PROT…
2018
Background Adding cyclic short sustained inflations (sigh) to assisted ventilation yields optimizes lung recruitment, decreases heterogeneity and reduces inspiratory effort in patients with acute hypoxemic respiratory failure (AHRF). These findings suggest that adding sigh to pressure support ventilation (PSV) might decrease the risk of lung injury, shorten weaning and improve clinical outcomes. Thus, we conceived a pilot trial to test the feasibility of adding sigh to PSV (the PROTECTION study). Methods PROTECTION is an international randomized controlled trial that will be conducted in 23 intensive care units (ICUs). Patients with AHRF who have been intubated from 24 h to 7 days and under…
Productive Efficiency of Decanters with Short and Variable Dynamic Pressure Cones
2003
Abstract This paper presents the results of experimental trials carried out on third-generation, variable dynamic pressure cone decanters to assess machine performance and adjust the process parameters for optimum extraction yield. The results obtained led to the following conclusions: the regulation of the differential velocity screw/bowl allows a better performance of the decanter at low dilutions of the olive paste; it is possible to obtain high efficiency at a low dilution of the olive paste achieving a higher minor compounds content and the more advanced system of regulation leads to better results according to the variations of the ratio between liquid and solid phases, thus optimisin…