Effect Of Transport Parameters Research Articles

The effect of transport parameters on regional economic development: The case of the Ural Federal District

The transport has a special role to play in the regional socioeconomic development, which changes depending on the prevailing trends for population mobility, introduction of advanced technologies, extension of economic connections, and growth in regional production. The study explores the problem of the interface between transport and regional economy on the example of the Ural Federal District. Methodologically, it relies on the theories of spatial development and regional economics. The main method of research is correlation and regression analysis. The evidence is the socioeconomic data on transport as well as values of gross regional product of the Ural Federal District for 2010–2020 sourced from the Federal State Statistics Service of the Russian Federation. The paper develops a model for forecasting GRP. The analysis indicates the presence of the relationship between the socioeconomic metrics of the transport sector and gross regional product of the Ural Federal District. In particular, there is the correlation between the indicators “density of public roads with hard surface”, “deaths in road accidents per 100,000 population” and gross regional product of the Ural Federal District. The paper concludes about the need to develop a composite indicator for assessing the transport sector that will reflect the ongoing digital modernisation and introduction of innovations.

Analysis of Factors for Compacted Clay Liner Performance Considering Isothermal Adsorption

The concentration profiles and breakthrough curves of the 2 m thick compacted clay liner (CCL) given in the specification were compared, considering three different adsorption isotherms (upper convex, linear, and lower concave). In addition, the effects of transport parameters, sorption isotherms, and source concentrations on pollutant migration were analyzed. The results showed that the dimensionless breakthrough curves of different source concentrations considering the linear adsorption isotherm coincided with each other, as the partition coefficient of the linear adsorption isotherm was constant. For the lower concave isotherm, the migration of a large source concentration was slowest, because the partition coefficient of the lower concave isotherm increased with an increase in concentration. For the upper convex isotherm, the migration of a large source concentration was fastest, because the partition coefficient decreased with an increase in concentration. The effects of the nonlinear isotherms on the shape of the outflow curve were similar to the effects of a change in the hydrodynamic dispersion (Dh): the concentration front of the upper convex isotherm was narrower, which was similar to the effect of a reduction in Dh (i.e., PL), and the concentration front of the lower concave isotherm was wider and similar to the effect of an increase Dh (i.e., PL). Therefore, the diffusion and adsorption parameters were fitted separately in the study, in case the nonlinear adsorption behavior was mistakenly defined as linear adsorption.

Experimental and numerical study on the leaching of pesticides into the groundwater through a porous medium: Effects of transport parameters

Abstract This study aims to investigate, experimentally and numerically, the pesticide transport through the soil in unsaturated zone. The movement of pesticide is described with one dimensional model. The transport equation incorporates terms accounting for diffusion –convection, adsorption and reaction. The first objective of this work was to identifies the effects of the parameters transport such us; the dimensions first order degradation coefficient ( μ ), the peclet number ( ρ e ) and the dimensionless mass transfer coefficient (w). The evolution of pesticide concentration in function of depth and time was found by using the non-equilibrium transport model. The data obtained show the importance of the adsorbed concentration. The second objective is to find the relation between the concentration and the transport parameters because there is a difficulty of the analytical solution. The solution of the problem was carried out by a numerical approach by using the finite difference method and a Fortran program.

Modeling the transport and capture of analytes in a two-phase heterogeneous microfluidic immunosensor

In a typical heterogeneous microfluidic immunosensor, the carrier fluid transports the target analytes to the antibodies immobilized on the channel surfaces with a thin liquid layer where they are captured. While single-phase systems (the carrier fluid being a liquid) are well studied, two-phase systems (the carrier fluid being a gas) are less explored. There in particular, the effect of transport parameters on the capture efficiency (a critical performance parameter) has not received much attention, and thus is the subject of study here. Hence, we have investigated the transport and capture of analytes in a two-phase heterogeneous microfluidic immunosensor wherein the target analytes in the gaseous phase are transported to the immobilized antibodies via gas–liquid interfacial mass transfer which strongly depends on flow variables of the gas phase flow. Parametric studies on capture efficiency using the properties of trinitrotoluene (TNT) were used to obtain the effects of important transport parameters on the capture of analyte molecules. The highlight of this work is the development of an empirical correlation between the capture efficiency and the gas-side non-dimensional interfacial mass transfer coefficient (Sherwood number, Shg). This could help design of a two-phase microfluidic device with improved performance parameters to capture gaseous analytes.

Effect of Transport Parameters and Device Geometry on Extraction Kinetics and Efficiency in Direct Immersion Solid-phase Microextraction.

An alternative strategy to increase mass transfer entails geometry optimization of the extraction systems including design of solid-phase microextraction (SPME) probes. In this work, a computational model was employed to elucidate practical aspects such as efficiency and kinetics of extraction by employing several new geometries. Extraction of a model analyte at static conditions with the configurations, such as thin-film, fiber, coated tip, and nanoparticles, was numerically simulated to obtain an in-depth understanding of the advantages and limitations of each geometry in microextraction and exhaustive modes. The attained results associated with the equilibration time dependency on shape were in good agreement with previously reported experimental observations. They demonstrate that the mass-transfer is highly dependent on the size and shape of the coatings and increases with a decrease in size of the devices particularly rapidly below 10 μm caused by radial diffusion effect. Nevertheless, extractions performed using octadecyl-functionalized magnetic nanoparticles demonstrated that higher enrichment factors are achievable with the use of a fewer number of particles in comparison to factors achieved via exhaustive extraction, where a larger number of particles must be employed, confirming theoretical predictions. The conclusions reached are valid for any extraction method. The results obtained herein are very useful toward the design and optimization of future extraction technologies and approaches.

Towards an integrated systems-based modelling framework for drug transport and its effect on tumour cells.

BackgroundA systematic understanding of chemotherapeutic influence on solid tumours is highly challenging and complex as it encompasses the interplay of phenomena occurring at multiple scales. It is desirable to have a multiscale systems framework capable of disentangling the individual roles of multiple contributing factors, such as transport and extracellular factors, and purely intracellular factors, as well as the interactions among these factors. Based on a recently developed systems-based modelling framework, we have developed a coupled system in order to further elucidate the role of drug transport, and its interplay with cellular signalling by incorporating intra- and extra-vascular drug transport in tumour, dynamic descriptions of intracellular signalling and tumour cell density dynamics.ResultsDifferent aspects of the interaction between transport and cell signalling and the effects of transport parameters have been investigated in silico. Limited drug penetration is found to be a major constraint in inducing drug effect; many aspects of the interaction of transport with cell signalling are independent of the details of cell signalling. A sensitivity analysis indicates that the effect of drug diffusivity depends on the balance between interstitial drug transport and the specific requirement for triggering apoptosis (governed by highly nonlinear signalling networks), suggesting that the effect of drug diffusivity in such cases must be considered in conjunction with descriptions of cellular dynamics.ConclusionsThe modelling framework developed in this study provides qualitative and mechanistic insights into the effect of drug on tumour cells. It provides an in silico experimental platform to investigate the interplay between extracellular factors (e.g. transport) and intracellular factors. Such a platform is essential to understanding the individual and combined effects of transport and cellular factors in solid tumour.

Modeling of Three-Way-Catalyst Monolith Converters with Microkinetics and Diffusion in the Washcoat

Two models of catalytic monolith reactor with diffusion in the washcoat are described, employing the nonstationary kinetics of CO and hydrocarbon oxidation, NOx reduction, and oxygen storage with 23 reaction steps. The first model describes the dynamic behavior in a short monolith (recirculation reactor or CSTR), and the second one is a spatially two-dimensional nonstationary model of the monolith with plug flow. The models are used to demonstrate the qualitative agreement between the observed nonlinear dynamics of CO oxidation, including hysteresis and periodic and period-doubled oscillations, and earlier experiments. The effects of transport parameters within the washcoat on the monolith lightoff and on the outlet conversions are simulated. Computed spatiotemporal concentration patterns of reaction intermediates within the washcoat layer are used to discuss the oxidation and reduction functions of the three-way-catalyst monolith.

Spatiotemporal patterns in a two-dimensional reaction-diffusion-convection system: Effect of transport parameters

We report on spatiotemporal patterns emerging in a system consisting of an autocatalytic reaction in a continuous flow tubular reactor. The autocatalyst undergoes a mutation and the resulting mutant is assumed to compete with the original autocatalyst. The system is modeled by a set of three partial differential equations with eight design parameters. We examine and discuss the effect of transport parameters, reactor inlet boundary condition, and reactor aspect ratio on the dynamics of the system. The results show a variety of regimes going from steady propagation of a reaction front to the development of chemical waves in the form of pulsating, more or less regularly, reaction front.

Chemical Kinetic Calculations of the Gas Phase in Filament‐Assisted Chemical Vapor Deposition of Diamond

A chemical kinetic model was developed for the gas mixture in filament‐assisted diamond chemical vapor deposition (CVD) systems. CH4/H2 mixture was studied as the starting gas mixture. The predictions of gas evolution calculated from this model were used to interpret certain published experimental observations. From the initial analysis, it was concluded that the thermodynamic state of the gas composition determined the effects of transport parameters on diamond growth. In many filament‐assisted diamond CVD systems the gas composition was found to be kinetically controlled. The analysis also suggested that CH3 is a major precursor of diamond films. When CH4/H2/O2 was used as the starting gas mixture, the results indicated that the oxygen additive catalyzed the process to increase the concentrations of CH3 and H, thereby increasing the growth rate and improving the quality of diamond films.