Search results for "Pressure"
showing 10 items of 4493 documents
Transition probabilities for BrII lines emitted from a wall-stabilized cascade arc
2000
Abstract Absolute transition probabilities of the eleven Br II lines were measured in emission. A plasma created in a wall-stabilized arc at atmospheric pressure in the mixture of argon and bromine vapors was used as the excitation source. The relative transition probabilities were converted to an absolute scale based on a lifetime value measured by the electron impact method. The results were compared with experimental data. Discrepancies have been found to be outside the experimental uncertainties.
Displacement Evolution of a Large Landslide in a Highly Fissured Clay
2019
The paper presents an analysis and modelling of the reactivation mechanism of a large landslide caused by rainfall, located in Cerda (Sicily, Italy). The study is based on data collected by means of a field investigation, carried out in order to assess the geotechnical properties of the involved material, and a three-year monitoring programme implemented to measure rain and pore water pressures as well as deep and superficial displacements. Three distinct landslides, evolving at variable rates in different directions, were recognized within the overall landslide area. The data clearly show the mechanical role of pore water pressures in the stability of the slope and point out the dependence…
Lattice Dynamics Study of HgGa2Se4 at High Pressures
2013
We report on Raman scattering measurements in mercury digallium selenide (HgGa2Se4) up to 25 GPa. We also performed, for the low-pressure defect-chalcopyrite structure, lattice-dynamics ab initio calculations at high pressures which agree with experiments. Measurements evidence that the semiconductor HgGa2Se4 exhibits a pressure-induced phase transition above 19 GPa to a previously undetected structure. This transition is followed by a transformation to a Raman-inactive phase above 23.4 GPa. On downstroke from 25 GPa until 2.5 GPa, a broad Raman spectrum was observed, which has been attributed to a fourth phase, and whose pressure dependence was followed during a second upstroke. Candidate …
Unveiling the role of the lone electron pair in sesquioxides at high pressure: compressibility of β-Sb2O3
2021
The structural, vibrational and electronic properties of the compressed beta-Sb2O3 polymorph, a.k.a. mineral valentinite, have been investigated in a joint experimental and theoretical study up to 23 GPa. The compressibility of the lattice parameters, unit-cell volume and polyhedral unit volume as well as the behaviour of its Raman- and IR-active modes under compression have been interpreted on the basis of ab initio theoretical simulations. Valentinite shows an unusual compressibility up to 15 GPa with four different pressure ranges, whose critical pressures are 2, 4, and 10 GPa. The pressure dependence of the main structural units, the lack of soft phonons, and the electronic density char…
High pressure phase transitions in NdVO4
2015
Raman-scattering measurements on NdVO4 suggest a pressure-induced zircon to monazite phase transition beyond 5.9 GPa. The monazite phase undergoes a second phase transition to a yet unknown phase at 18.1 GPa. Lattice-dynamics calculations well support the experimental findings and predict a possible orthorhombic structure for the post-monazite structure of NdVO4.
Strict blood-pressure control and progression of renal failure in children
2009
PubMedID: 19846849 BACKGROUND: Although inhibition of the renin-angiotensin system delays the progression of renal failure in adults with chronic kidney disease, the blood-pressure target for optimal renal protection is controversial. We assessed the long-term renoprotective effect of intensified blood-pressure control among children who were receiving a fixed high dose of an angiotensin-converting- enzyme (ACE) inhibitor. METHODS: After a 6-month run-in period, 385 children, 3 to 18 years of age, with chronic kidney disease (glomerular filtration rate of 15 to 80 ml per minute per 1.73 m2 of body-surface area) received ramipril at a dose of 6 mg per square meter of bodysurface area per day…
Ambulatory Blood Pressure Values in the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET)
2012
In the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial, telmisartan (T; 80 mg daily) and ramipril (R; 10 mg daily) caused similar clinic blood pressure (BP) reductions, with a similar incidence of cardiovascular and renal events. The R+T combination lowered clinic BP somewhat more with no further cardiovascular or renal protection. The aim of this substudy was to see whether these clinic BP changes reflected the changes of 24-hour BP, a BP with a better prognostic value. In 422 patients in whom 24-hour BP monitoring was performed either before or after 6 to 24 months of treatment, demographic and clinical characteristics were similar in the 3 treated groups.…
Prognostic value of blood pressure in patients with high vascular risk in the Ongoing Telmisartan Alone and in combination with Ramipril Global Endpo…
2009
Hypertension guidelines advise aggressive blood pressure (BP) lowering in patients with diabetes or high cardiovascular risk, but supporting evidence is limited. We analysed the impact of BP on cardiovascular events in well treated high-risk patients enrolled in a large clinical trial (Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial).Twenty-five thousand five hundred and eighty-eight patients with atherosclerotic disease or diabetes with organ damage, tolerant to angiotensin-converting enzyme inhibitors, were randomized to ramipril, telmisartan or both. We related the primary composite outcome and its components to: baseline SBP; SBP changes from baseline to…
Antihypertensive and cardiovascular effects of combined blockade of renin-angiotensin system with ACE inhibitor and angiotensin II type 1 receptor bl…
2006
BACKGROUND.: In this study the effects of 24 weeks losartan and ramipril treatment, both alone and in combination, on blood pressure and left ventricular mass (LVM) and function, have been evaluated in hypertensives. METHODS.: 57 hypertensives with stage 1 and 2 essential hypertension were included. After 4 weeks run in, a randomized double-blind, 3 arm, double dummy, independent trial was used. All patients were randomly allocated to 3 treatment arms consisting of losartan (50 mg/daily), ramipril (5 mg/daily), and combined (losartan 50 mg/ramipril 5 mg/daily) for 24 weeks. LVM, LVM/h(2.7) and other echocardiographic measurements, BUN, creatinine and clearance and potassium were determined …
Visit-to-visit blood pressure variability and renal outcomes: results from ONTARGET and TRANSCEND trials.
2020
AIMS There is conflicting evidence on whether in treated hypertensive patients the risk of renal outcomes is associated with visit-to-visit SBP variability. Furthermore, limited evidence is available on how important is SBP variability for prediction of renal outcomes compared with on-treatment mean SBP. We addressed these issues in 28 790 participants of the Ongoing Treatment Alone and in combination with Ramipril Global End point Trial and Telmisartan Randomized Assessment Study in ace iNtolerant Subjects with Cardiovascular Disease trials. METHODS AND RESULTS SBP variability was expressed as the coefficient of variation of the mean with which it showed no relationship. SBP variability an…