Search results for "Mass transport"
showing 8 items of 28 documents
Sustainable Mobility in Park Areas: The Potential Offered by Guided Transport Systems
2012
The project choices to design and manage a transport infrastructure system are extremely hard in thinly populated areas like, for instance, protected areas and mostly parks. In actual fact, the need for promotion and development of these areas, often characterized by large surfaces, contrasts with the necessity to preserve their inestimable natural value. The transportation demand in extremely sensible environmental contexts can be satisfied by providing incentives to use reduced-impact means of transport, regulating adequately the vehicle traffic flow and promoting the intermodality between private and public transport systems. Apart from performing their own traditional functions, these s…
Stratosphere–Troposphere Exchange and Its Relation to Potential Vorticity Streamers and Cutoffs near the Extratropical Tropopause
2007
Abstract Two distinct dynamical processes near the dynamical tropopause (2-PVU surface) and their relation are discussed in this study: stratosphere–troposphere exchange (STE) and the formation of distinct potential vorticity (PV) structures in the form of stratospheric and tropospheric streamers and cutoffs on isentropic surfaces. Two previously compiled climatologies based upon the 15-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-15) dataset (from 1979 to 1993) are used to establish and quantify the link between STE and these PV structures. An event-based analysis reveals a strong relation between the two processes. For instance, on isentropes below 320 K, 30%–50%…
Photoinduced mass transport in soft materials
2011
The surface relief grating formation in amorphous As2S3 and azo-benzene polymer films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector.
Ionic Liquids on Demand in Continuous Flow
2009
We report on the development of an alternative protocol for the facile, solvent-free synthesis of various novel imidazolium-based ionic liquids (ILs) that affords highly pure products without the necessity of subsequent purification steps. The continuous approach is based on the combination of HPLC pumps with a micromixer and a capillary residence tube. Our system provides a high degree of control over the alkylation reactions due to a high surface-to-volume ratio and superior heat and mass transport. Within the scope of our studies, we focused on ionic liquids containing differently substituted phenyl rings and characterized these compounds with respect to further use for direct applicatio…
Characterization of microscopic disorder in reconstructed porous materials and assessment of mass transport-relevant structural descriptors
2016
The targeted optimization of the functional properties of porous materials includes the understanding of their transport properties and thus requires knowledge about the relationship between material synthesis, resulting in three-dimensional material morphology, and relevant transport properties. In this Perspective, we present our views and results on the characterization of microscopic disorder in functional porous materials, which are widely used today as fixed beds in adsorption, separation, and catalysis. This allows us to identify structural parameters that impact their mass transport properties and eventually their overall performance in technological operations. We address this comp…
kLa MEASUREMENT IN BIOREACTORS
2010
For accurately measuring kLa in bioreactors the dynamic pressure method (DPM) was introduced by Linek et al. (1993). In this work a simplified version of the same method is discussed. With respect to the original DPM, the simplified version greatly simplifies data treatment. In fact final constant slope observable in the usual semi-log diagram of residual driving force versus time may be simply corrected to obtain the real kLa value with negligible inaccuracy. Experimental data obtained on a lab-size stirred tank reactor confirm all model predictions, including the feature that the adoption of large pressure changes may lead to a better accuracy.
Existence of optimal transport maps in very strict CD(K,∞) -spaces
2018
We introduce a more restrictive version of the strict CD(K,∞) -condition, the so-called very strict CD(K,∞) -condition, and show the existence of optimal maps in very strict CD(K,∞) -spaces despite the possible lack of uniqueness of optimal plans. peerReviewed
Application of computational fluid dynamics technique in electrodialysis/reverse electrodialysis processes
2022
This Chapter treats the application of CFD technique in ED/RED processes. CFD simulations are able to predict flow and mass transfer in channels filled with spacers or membrane profiles, by providing dimensionless correlations useful for process models. At a larger scale, manifolds of the stack and inlet/ outlet zones of the channel can be simulated. Numerical models can include the computation of the electrical potential, thus characterizing the process performance. Direct numerical simulations can elucidate the complex phenomenology of overlimiting transport and of chaotic electrokinetic flows.