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High temperature applications of spiral wound modules for UF and NF

The most common modules for ultrafiltration (UF) and nanofiltration (NF) are spiral wound elements due to their low investment, easy replacement and high packing density. Operating at high temperatures greater than 70°C, the use of spiral wound modules is, however, often limited. In the past ceramic membranes have been considered as the only viable option to operate at these temperatures. However,

Parton cascade models and QCD coherence at HERA

The hadronic final state in deep-inelastic ep scattering at HERA is influenced by colour coherence effects in QCD. Three different models for initial- and final-state multi-parton emission and soft hadronization, as implemented in the Monte Carlo programs LEPTO, ARIADNE and HERWIG, are compared in this respect both at the parton and hadron level (with experimental conditions taken into account).

Cardiac Remodeling in Aortic and Mitral Valve Disease - a Simulation Study with Clinical Validation

BACKGROUND: Remodeling is an important long-term determinant of cardiac function throughout the progression of heart disease. Numerous biomolecular pathways for mechanosensing and transduction are involved. However, we hypothesize that biomechanical factors alone can explain changes in myocardial volume and chamber size in valve disease.METHODS: A validated model of the human vasculature and the f

Membrane spacers for ultrafiltration: Modelling of mass transfer and pressure

Membrane spacers are an essential part of spiral wound modules and can significantly influence the mass transfer performance and pressure drop in the modules. To develop further understanding of the importance of spacer selection, the performance of two configurations of parallel spacers for ultrafiltration using Dextan T40 was analysed in this study using lab-scale experiments and CFD simulations

Agreement of left ventricular mass in steady state free precession and delayed enhancement MR images : Implications for quantification of fibrosis in congenital and ischemic heart disease

Background: Left ventricular mass (LVM) is used when expressing infarct or fibrosis as a percentage of the left ventricle (LV). Quantification of LVM is interchangeably carried out in cine steady state free precession (SSFP) and delayed enhancement (DE) magnetic resonance imaging (MRI). However, these techniques may yield different LVM. Therefore, the aim of the study was to compare LVM determined

Color structure for soft gluon resummation: A General recipe

A strategy for calculating the color structure needed for soft gluon resummation for processes with any number of colored partons is introduced using a Nc → ∞inspired basis. In this basis a general formalism can be found at the same time as the calculations are simplified.The advantages are illustrated by recalculating the soft anomalous dimension matrix for the processes gg → gg, qq → qqg and qq

The theory of dynamical random surfaces with extrinsic curvature

We analyse numerically the critical properties of a two-dimensional discretized random surface with extrinsic curvature embedded in a three-dimensional space. The use of the toroidal topology enables us to enforce the non-zero external extension without the necessity of defining a boundary and allows us to measure directly the string tension. We show that a phase transition from the crumpled phase

Multiple interactions, diffraction, and the BFKL pomeron

In high energy pp scattering the inclusive cross section for minijet production is very large. Unitarity then implies a high probability for multiple interactions, and a large diffractive cross section. As the proton has a substructure in terms of parton cascades, the diffraction is not only elastic, but has a large component of diffractive excitation. The cascades can fill the whole rapidity ran

Negative predictive value and potential cost savings of acute nuclear myocardial perfusion imaging in low risk patients with suspected acute coronary syndrome : A prospective single blinded study

Background: Previous studies from the USA have shown that acute nuclear myocardial perfusion imaging (MPI) in low risk emergency department (ED) patients with suspected acute coronary syndrome (ACS) can be of clinical value. The aim of this study was to evaluate the utility and hospital economics of acute MPI in Swedish ED patients with suspected ACS. Methods: We included 40 patients (mean age 55

Spiral wound modules for high viscosity solutions at high temperature: Carrageenan concentration with ultrafiltration

Spiral wound modules are the most common modules in the industry due to their low investment and replacement costs plus high packing density. The use of spiral wound modules is often restricted to feed streams with a low temperature (< 75°C) and a low viscosity. The focus of this paper is on a new generation of spiral wound modules, which has been introduced by Alfa Laval Membrane Technology for t

Disappearance of myocardial perfusion defects on prone SPECT imaging : Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease

Background: It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT) in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position ha

Scaling properties at the crumpling transition

We investigate numerically a dynamically triangulated random surface with extrinsic curvature embedded in a three-dimensional space. Toroidal topology is used, to allow for string tension measurements by a new method. A high statistics test of the finite-size scaling of the specific heat is performed.