Search results for "Pressure"

Modelling flow and heat transfer in spacer-filled membrane distillation channels using open source CFD code

2013

Abstract A good understanding of the details of hydrodynamic and heat transport conditions and their impact on temperature polarisation and pressure drops is essential for optimum design of membrane distillation (MD) modules. To this end, the present work reports on initial progress in the development of a tool for 3D simulation of spacer-filled MD channels based on the open source CFD code library OpenFOAM. The paper discusses a number of modelling and implementation aspects including model geometry and computational domain, choice of boundary conditions, and discretisation schemes. The results pertaining to the effect of three different spacer types on the fluid dynamics and heat transfer…

Friction and Heat Transfer in Membrane Distillation Channels: An Experimental Study on Conventional and Novel Spacers

2022

The results of an experimental investigation on pressure drop and heat transfer in spacer-filled plane channels, which are representative of Membrane Distillation units, are presented and discussed. Local and mean heat transfer coefficients were obtained by using Thermochromic Liquid Crystals and Digital Image Processing. The performances of a novel spacer geometry, consisting of spheres that are connected by cylindrical rods, and are hereafter named spheres spacers, were compared with those of more conventional woven and overlapped spacers at equal values of the Reynolds number Re (in the range ~150 to ~2500), the pitch-to-channel height ratio, the flow attack angle and the thermal boundar…

Temperature measurement in gas mixtures by femtosecond Raman-induced polarization spectroscopy

2003

European Conference on Nonlinear Optical Spectroscopy (ECONOS) MAR 30-APR 01, 2003 BESANCON, FRANCE; The potential of femtosecond Raman-induced polarization spectroscopy (RIPS) for the simultaneous determination of temperature and concentrations was investigated. These measurements were related to the rotational time response of the molecular gas mixture, which was measured as a function of the pump-probe time delay. The change of the polarizability anisotropy with respect to the vibrational levels was taken into account. The results of temperature measurements in pure CO2 showed good agreement with the values obtained by a thermocouple. The RIPS technique was also applied to a CO2-N2 gas m…

Realization of time-resolved two-vacuum-ultraviolet-photon ionization

2009

International audience; Ultrafast dynamics of excited molecules is studied through time-resolved two-vacuum-ultraviolet (vuv)- photon ionization using a nonlinear volume autocorrelator unit. The two-vuv-photon process is induced by the intense fifth harmonic radiation of a femtosecond Ti:sapphire laser. In a proof-of-principle experiment, ultrafast dynamics of excited ethylene and oxygen molecules are investigated. Molecular decay times are deduced by comparing the experimental data with the results of a numerical model that accounts for the spatial and temporal characteristics of the harmonic field. The present experiments pave a convenient way for time domain investigations in the vuv-xuv s…

Absence of Adverse Effects of Tiotropium/Olodaterol Compared with the Monocomponents on Long-Term Heart Rate and Blood Pressure in Patients with Mode…

2020

Stefan Andreas,1,2 Lorcan McGarvey,3 Ulrich Bothner,4 Matthias Trampisch,4 Alberto de la Hoz,4 Matjaz Fležar,5 Roland Buhl,6 Peter Alter7 1Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany; 2LungClinic Immenhausen, Immenhausen, Germany, Member of the German Center for Lung Research (DZL); 3Queen’s University Belfast, Belfast, UK; 4Boehringer Ingelheim International GmbH, Ingelheim am Rhein, Germany; 5Klinika Golnik, Golnik, Slovenia; 6Pulmonary Department, Johannes Gutenberg University Mainz, Mainz, Germany; 7Department of Medicine, Pulmonary and Critical Care Medicine, Philipps University of Marburg (UMR); Member o…

Effect of network pressure on apparent losses due to meters under-registration

2010

The effects of statins on blood pressure: current knowledge and future perspectives.

2012

Past, present, and future of green product innovation

2021

Firms are under constant pressure from various governmental and nongovernmental agencies to switch from conventional environmentally polluting products to green product innovations (GPIs). However, the relevant research pertaining to GPI has been published in a diverse set of journals that vary in their scope and readership and, therefore, the scholarly contribution to the topic remains largely fragmented. This study has utilised a systematic literature review approach to examine the literary corpus on GPI to paint a holistic picture of its different aspects. The content and thematic analysis of 85 studies resulted in the extraction of seven key research themes: organisational capabilities,…

Virtualization of work in global supply chains

2016

ABSTRACT. Background: The paper is devoted to the notion and benefits of implementing virtual work in global supply chains. Virtual work must be understood as an intentional activity of a human being, aimed at rendering services (tangible and intangible), by means of ITC tools, performed in a distance from the traditional place of work, in a mobile manner. The empirical research were conducted on the basis of 4 case studies of global leaders of supply chains, which in accordance with M. Fisher's classification, represent two types. The case studies confirmed the positive influence of virtual work both in effective and flexible supply chains. Favourable market and technological conditions an…

Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…

2005

Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…