Evaluation of Matrix-Fracture Transfer Functions for Counter-Current Capillary Imbibition

Different functions describing matrix-fracture transfer were tested for counter-current capillary imbibition interaction. The recovery curves obtained from capillary imbibition experiments were used to fit the transfer functions. The exponential coefficients yielding the best fit to the experimental data were obtained and correlated to the effective parameters such as viscosity, IFT, matrix length and diameter, matrix permeability and porosity, and wettability using multivariable regression analysis. In order to obtain the recovery curves, experiments were conducted on Berea sandstone and Indiana limestone samples. Cylindrical samples with different shape factors were obtained by cutting the plugs 1, 2.5, and 5 cm in diameter and 2.5, 5, and 10 cm in length. All sides were coated with epoxy except one end. More than fifty static imbibition experiments were carried out on vertically and horizontally situated samples where the imbibition took place upward and lateral directions, respectively. Brine–air, brine–kerosene, brine–mineral oil, and surfactant solution–mineral oil pairs were used as fluids. For many matrix shape factors (especially longer and small diameter ones), dividing the recovery curve into three parts were needed as the early, intermediate, and late times, which are typically distinguished by the time required for the imbibition front to reach the closed boundary at the end of the core. Correlations among the exponential coefficients and rock/fluid properties were developed. It was observed that different rock/fluid properties and transfer mechanisms (capillary imbibition and gravity drainage) govern the process for each part. Hence, the analyses done in this study were useful not only for developing explicit transfer functions but also identifying the physics of the counter-current imbibition recovery.     

On the design of Robust‐WDM local area networks

Robust wavelength division multiplexing (Robust‐WDM) is a proposal to realize cost‐effective WDM local area networks (LANs) which can get around the expensive need for laser wavelength stabilization. The type of these networks that relies on an access protocol with aperiodic reservations and lenient‐token‐passing based control channel (the AR/LTP protocol) is promising. We look at the deployment of the AR/LTP analytical model in designing this type of network. The model is used to predict the effect of component and network parameters on the waiting time characteristics of the network. An increase in node operation times (i.e. receiver response time, transmitter select time and reservation period) would result in increasing the average waiting time of a connection request, but the waiting time is more sensitive to the physical span of the network and its size. It is also observed that increasing the inter‐reservation threshold may result in little increase in waiting time up to some limit beyond which delay increases rapidly. Copyright © 2001 John Wiley & Sons, Ltd.     

Optimized Green Extraction of Polyphenols from Cassia javanica L. Petals for Their Application in Sunflower Oil: Anticancer and Antioxidant Properties

The total phenolic content (TPC) from Cassia javanica L. petals were extracted using ethanolic solvent extraction at concentrations ranging from 0 to 90% and an SCF-CO₂ co-solvent at various pressures. Ultrasound-assisted extraction parameters were optimized using response surface methodology (RSM). Antioxidant and anticancer properties of total phenols were assessed. An SCF-CO₂ co-solvent extract was nano-encapsulated and applied to sunflower oil without the addition of an antioxidant. The results indicated that the best treatment for retaining TPC and total flavonoids content (TFC) was SCF-CO₂ co-solvent followed by the ultrasound and ethanolic extraction procedures. Additionally, the best antioxidant activity by β-carotene/linoleic acid and DPPH free radical-scavenging test systems was observed by SCF-CO₂ co-solvent then ultrasound and ethanolic extraction methods. SCF-CO₂ co-solvent recorded the highest inhibition % for PC3 (76.20%) and MCF7 (98.70%) and the lowest IC₅₀ value for PC3 (145 µ/mL) and MCF7 (96 µ/mL). It was discovered that fortifying sunflower oil with SCF-CO₂ co-solvent nanoparticles had a beneficial effect on free fatty acids and peroxide levels. The SCF-CO₂ method was finally found to be superior and could be used in large-scale processing.     

Study on QoS Management for Video Streaming in Vehicular Ad Hoc Network (VANET)

Wireless Personal Communications - Vehicular Ad Hoc Network (VANET) is a particular type of MANET providing various wireless communications such as infrastructure communications and inter-vehicle...     

Construction of a stable vehicular ad hoc network based on hybrid genetic algorithm

Telecommunication Systems - In vehicular ad hoc networks, the vehicle speed can exceed 120 kmph. Therefore, any node can enter or leave the network within a very short time. This mobility adversely...     

A validated RP‐HPLC method for the evaluation of the influence of grapefruit juice on liver S9 activation of sacubitril

Grapefruit juice inhibits esterase enzyme. Therefore, a possible interaction with ester prodrugs should be taken into consideration. In this study, the influence of grapefruit juice on sacubitril (SAC) rat liver S9 activation by esterase enzyme was evaluated. An RP‐HPLC method was developed and validated for estimation of SAC in rat liver S9 fraction using a C₁₈ Cyano column as stationary phase and acetonitrile–sodium di‐hydrogen phosphate buffer (0.02 m , pH 4 adjusted by o‐phosphoric acid, 40:60, v/v), as mobile phase at a flow rate of 1 mL/min and UV detection at 254 nm. The method was successfully applied to an in vitro study in which SAC was incubated with rat liver S9 fraction prepared from rats that had previously ingested grapefruit juice for a week. The calculated SAC concentration after incubation was compared with that of SAC incubated with rat liver S9 fraction from the rat control group. The statistical significance between the results of test and control incubation sets was assessed. In conclusion, the current study demonstrated that grapefruit juice decreased SAC hydrolysis, hence delaying its activation to sacubitrilat (active form) in gut lumen. Based on this food–drug interaction, it may be required that grapefruit juice should be consumed with caution in patients receiving SAC.     

Enhancing VANETs Broadcasting Performance with Mobility Prediction for Smart Road

Wireless Personal Communications - In the last decade, daily lifestyles have been invaded by mobile networks which added a huge exchange of information. This exchange among vehicular nodes as a...     

Structural,DFT/B3LYP and molecular docking studies of binuclear thiosemicarbazide Copper (II) complexes and their biological investigations

Thiosemicarbazide copper (II) complexes; [Cu₂(HL¹)₂(H₂O)₂Cl₂].H₂O (1) and [Cu₂(HL²)₂(H₂O)₂Cl₂].2H₂O (2) (where H₂L¹ = 2-picolinoyl-N-(pyridin-2-yl)hydrazine-1-carbothioamide and H₂L² = 2-(2-(2-aminothiazol-4-yl)acetyl)-N-(pyridin-2-yl)hydrazine-1-carbothioamide) have been synthesized and characterized. Analytical and spectroscopic data revealed that ligands behaves as monobasic tetradentate with octahedral geometry. In addition, the optimized geometry of the ligands and their complexes was approved with the Jaguar 9.1 program in the Schrödinger set using DFT (density functional theory) to predict chemical processes and to estimate the properties of the material made by the hybrid functional density system B3LYP. Furthermore, the thermal degradation curves of complexes were discussed in order to determine the kinetic and thermodynamic parameters by various approaches. Additionally, the antioxidant (using the DPPH and SOD methods) and the antibacterial potency of the compounds were examined. Also, docking study of ligands and their complexes was carried out against Staphylococcus aureus gram +ve, gram -ve bacterial strains of Escherichia coli and Candida albicans using the XP glide protocol of Schrödinger suite.     

Electronic Simulation of Neutronic Transient Studies for PWR-900 MW(e)

To study different functionalities of the PWR-900 MW(e) reactor core, an electronic model of Simulation Program with Integrated Circuit Enfesied (PSPICE) for electronic circuit design was adopted to model the mathematical models. A classical breadboard electronically simulates the physical terminal characteristics of each network. The electronic simulator, parity simulator, for reactor core can simulate six-delayed neutron groups, single prompt neutron, neutron source, fuel channel, the coolant, reactor poisons, temperature feedback, control rods, safety rods, and boron injection. Positive/negative step or sin reactivity functions are two case studies were analyzed. The obtained results were found to be in a good agreement with the available data of El-Dabaa PWR 900 MW(e) basic simulator.     

Solution of pressure diffusion in radially composite reservoirs

This paper presents a new general method for solving the pressure-diffusion equation in cylindrically radial composite reservoirs, where the rock and fluid properties may change radially as a function ofr. Composite systems, such as formations with wellbore filtrate invasion and reservoirs with peripheral water encroachment, can be encountered as a result of drilling, secondary oil recovery, and water influx.The new solution method utilizes the reflection and transmission concept of electromagnetics to solve fluid flow problems in three-dimensional cylindrically radial reservoirs, where heterogeneity is in only one direction. The Green's function for a point source in a three-dimensional radially composite system is developed by using the reflection and transmission method. The method as well as the point source solution are sufficiently general that they may be applied to similar fluid flow and well testing problems involving single-phase flow.