Search results for "Pressure"
showing 10 items of 4493 documents
Temperature- and pressure-dependent structural study of {Fe(pmd) 2[Ag(CN)2 ]2}n spin-crossover compound by neutron Laue diffraction
2014
The effect of pressure (up to 0.17GPa) on the spin-crossover compound {Fe(pmd)2[Ag(CN)2]2} n [orthorhombic isomer (II), pmd = pyrimidine] has been investigated by temperature- and pressure-dependent neutron Laue diffraction and magnetometry. The cooperative high-spin ↔ low-spin transition, centred at ca 180K at ambient pressure, is shifted to higher temperatures as pressure is applied, showing a moderate sensitivity of the compound to pressure, since the spin transition is displaced by ca 140KGPa-1. The space-group symmetry (orthorhombic Pccn) remains unchanged over the pressure-temperature (P-T) range studied. The main structural consequence of the high-spin to low-spin transition is the c…
CT-Densitometrie zur Analyse der statischen Druckvolumenkurve der Lunge bei experimentell induziertem Lungenschaden
2005
Purpose: To study quantitative changes of lung density distributions when recording in- and expiratory static pressure-volume curves by single slice computed tomography (CT). Materials und Methods: Static in- and expiratory pressure volume curves (0 to 1000ml, increments of 100ml) were obtained in random order in 10 pigs after induction of lung damage by saline lavage. Simultaneously, CT acquisitions (slice thickness 1 mm, temporal increment 2 s) were performed in a single slice (3 cm below the carina). In each CT image lung segmentation and planimetry of defined density ranges were achieved. The lung density ranges were defined as: hyperinflated (-1024 to -910 HU), normal aerated (-910 to …
Investigation of Inspiratory Pressure-Volume Curves on Mechanically Ventilated Patients Using Least Square Polynomial Fit
1988
Abstract An on-line method for the registration of pressure volume 1 oops TrT mechanically ventilated patients was developed using a personal computer with analog/digital interface. A third order polynomial function was fitted to the measured inspiratory pressure volume pairs. The significance of the fitting procedure was calculated using regression ANOVA. The inflection point of the pressure-volume curve was determinated by calculating the root of the second derivative of the polynomial. The method was teseted on 20 patients without major pulmonary dysfunction and on 6 patients with severe ARDS.
Zinc Oxide Nanowires on Printed Circuit Boards
2015
Printed circuit boards (PCBs), which are widely used for the fabrication of electronic circuits, can only withstand rather low temperatures. For this reason, the fabrication of high-density, long ZnO nanostructures on PCBs still remains a complex task. In fact, in absence of a seed-layer, whose annealing would require high temperatures, solution-growth methods only allow to synthesize low-density arrays of nanowires. Here we evaluate methods for overcoming this issue and, as a prototype, demonstrate a simple displacement sensor.
Modelling and optimization of modular system for power generation from a salinity gradient
2019
Abstract Pressure retarded osmosis has been proposed for power generation from a salinity gradient resource. The process has been promoted as a promising technology for power generation from renewable resources, but most of the experimental work has been done on a laboratory size units. To date, pressure retarded osmosis optimization and operation is based on parametric studies performed on laboratory scale units, which leaves a gap in our understanding of the process behaviour in a full-scale modular system. A computer model has been developed to predict the process performance. Process modelling was performed on a full-scale membrane module and impact of key operating parameters such as h…
New preparation of ceramic coatings by low-pressure plasma spray
2018
As an advanced thermal spray technology, low-pressure plasma spray (LPPS) allows obtaining high-quality coatings and can bridge the thickness gap between conventional thermal spray technologies and standard thin film processes. Moreover, LPPS permits to build uniform coatings with various microstructures; deposition takes place not only from liquid splats but also from nano-sized clusters as well as from the vapor phase depending on operational conditions. In order to further improve and develop the LPPS process, this research aims to combine it with the emerging suspension plasma spray and reactive plasma spray processes. It was expected to both provide two novel integrated processes and a…
Enantioselective alkynylation of benzo[e][1,2,3]-oxathiazine 2,2-dioxides catalysed by (R)-VAPOL-Zn complexes: synthesis of chiral propargylic cyclic…
2015
[EN] (R)-VAPOL-Zn(II) complexes catalysed the enantioselective addition of terminal alkynes to cyclic benzoxathiazine 2,2-dioxides, providing the corresponding chiral propargylic sulfamidates with high yields (up to 93%) and good enantiomeric excesses (up to 87%).
Relative contribution of different l-arginine sources to the substrate supply of endothelial nitric oxide synthase
2011
In certain cases of endothelial dysfunction l-arginine becomes rate-limiting for NO synthesis in spite of sufficiently high plasma concentrations of the amino acid. To better understand this phenomenon, we investigated routes of substrate supply to endothelial nitric oxide synthase (eNOS). Our previous data with human umbilical vein (HUVEC) and EA.hy.926 endothelial cells demonstrated that eNOS can obtain its substrate from the conversion of l-citrulline to l-arginine and from protein breakdown. In the present study, we determined the quantitative contribution of proteasomal and lysosomal protein degradation and investigated to what extent extracellular peptides and l-citrulline can provide…
HPLC demonstration that an all Trp--Phe replacement in gramicidin A results in a conformational rearrangement from beta-helical monomer to double-str…
1995
We have taken advantage of our previously reported high performance liquid chromatographic (HPLC) strategy to investigate the conformational behavior of the optically reversed gramicidin M (gM-), an analog of gramicidin A with all tryptophans replaced by phenylalanines, in different model membranes. It is quantitatively demonstrated for the first time that once inserted in the lipid environment, gM- (unlike the native peptide) undergoes a conformational transition from beta-helical monomers to thermodynamically stable double-stranded dimers. This transition is faster the higher the incubation temperature and can be neatly observed in both small unilamellar phospholipid vesicles and lysophos…
The impact of high hydrostatic pressure on structure and dynamics of beta-lactoglobulin
2013
Abstract Methods Combining small-angle X-ray and neutron scattering measurements with inelastic neutron scattering experiments, we investigated the impact of high hydrostatic pressure on the structure and dynamics of β-lactoglobulin (βLG) in aqueous solution. Background βLG is a relatively small protein, which is predominantly dimeric in physiological conditions, but dissociates to monomer below about pH 3. Results High-pressure structural results show that the dimer–monomer equilibrium, as well as the protein–protein interactions, are only slightly perturbed by pressure, and βLG unfolding is observed above a threshold value of 3000 bar. In the same range of pressure, dynamical results put …