Natural convection in polyethylene glycol based molybdenum disulfide nanofluid with thermal radiation, chemical reaction and ramped wall temperature

© 2018 International Information and Engineering Technology Association. All Rights Reserved. The aim of this study is to investigate the unsteady magnetohydrodynamic (MHD) flow of Casson nanofluid over an infinite oscillating vertical plate with ramped wall temperature. The effects of porosity, thermal radiation and first order chemical reaction have been considered. Polyethylene glycol (PEG) is chosen as base fluid which contained molybdenum disulfide (MoS 2 ) nanoparticles. The Laplace transform technique is applied to the momentum, energy and concentration equations to obtain the closed form solutions. The obtained solutions are for both cases ramped and isothermal boundary conditions and compared graphically. From graphical analysis, it is observed that for isothermal plate, the magnitude of velocity, temperature and concentration profiles are greater than ramped wall temperature. Skin-friction, Nusselt number and Sherwood number are evaluated and presented in tabular forms. The effects of various embedded parameters on velocity, temperature and concentration profiles are discussed graphically

Mitigating MAC Layer Performance Anomaly of Wi-Fi Networks through Adaptable Channelization

. 802.11 wireless local area networks (WLANs) can support multiple data rates at physical layer by using adaptive modulation and coding (AMC) scheme. However, this differential data rate capability introduces a serious performance anomaly in WLANs. In a network comprising of several nodes with varying transmission rates, nodes with lower data rate (slow nodes) degrade the throughput of nodes with higher transmission rates (fast nodes). The primary source of this anomaly is the channel access mechanism of WLANs which ensures long term equal channel access probability to all nodes irrespective of their transmission rates. In this work, we investigate the use of adaptable width channelization to minimize the effect of this absurdity in performance. It has been observed that surplus channel-width due to lower transmission rate of slow nodes can be assigned to fast nodes connected to other access points (APs), which can substantially increase the overall throughput of the whole network. We propose a medium access control (MAC) layer independent anomaly prevention (MIAP) algorithm that assigns channel-width to nodes connected with different APs based on their transmission rate. We have modeled the effect of adaptable channelization and provide lower and upper bounds for throughput in various network scenarios. Our empirical results indicate a possible increase in network throughput by more than 20% on employing the proposed MIAP algorith

Convection in ethylene glycol-based molybdenum disulfide nanofluid: Atangana–Baleanu fractional derivative approach

© 2018, Akadémiai Kiadó, Budapest, Hungary. This article aims to study the flow of ethylene glycol-based molybdenum disulfide generalized nanofluid over an isothermal vertical plate. A fractional model with non-singular and non-local kernel, namely Atangana–Baleanu fractional derivatives, is developed for Casson nanofluid in the form of partial differential equations along with appropriate initial and boundary conditions. Molybdenum disulfide nanoparticles of spherical shape are suspended in ethylene glycol taken as conventional base fluid. The exact solutions are developed for velocity and temperature via the Laplace transform technique. In limiting sense, the obtained solutions are reduced to fractional Newtonian (β→ ∞) , classical Casson fluid (α→ 1) and classical Newtonian nanofluid. The influence of various pertinent parameters is analyzed in various plots with the useful physical discussion

Engine oil based generalized brinkman-type nano-liquid with molybdenum disulphide nanoparticles of spherical shape: Atangana-Baleanu fractional model

© 2017 Wiley Periodicals, Inc. The impact of magnetic field on Engine Oil based generalized Brinkman-type nanofluid over an oscillating vertical plate embedded in a porous medium is studied. Molybdenum Disulphide (MoS2) nanoparticles of spherical shape are suspended in Engine Oil, taken as conventional base fluid. Effect of thermal radiation in energy equation is also considered. A generalized model of Brinkman-type fluid is considered with newly introduced fractional derivatives known as Atangana-Baleanu Derivative (ABD) in the presence of heat transfer due to convection. Exact solution of the problem is determined by means of the Laplace transform. Expressions for velocity and temperature are obtained in terms of Mittag-Leffler and General Wright function. The effects of various pertinent parameters on velocity are portrayed and discussed graphically. Numerical results of rate of heat transfer are computed in tabular form. Which showed that increasing values of volume fraction and Prandtl number increase rate of heat transfer