Thermo-hydraulic performance investigation of solar air heater duct having staggered D-shaped ribs: Numerical approach

The thermohydraulic performance (THP) of a solar air heater (SAH) duct with staggered D-shaped ribs as roughness geometry is examined in this work using three-dimensional numerical investigation. The investigation is carried out at roughness parameters of radius of rib to transverse pitch (r/P_tv) ratios of 0.1–0.35 and longitudinal pitch to radius of rib (P_lg/r) ratios of 4–10 under varied operating circumstances of Reynolds number (Re) from 10,200 to 20,200. The maximum Nusselt number (Nu) is obtained to be 81.3 at Re of 20,200, r/P_tv as 0.1, and P_lg/r as 4. In contrast, the maximum friction factor (f) is obtained to be 0.0169 at Re of 10,200, r/P_tv as 0.35, and P_lg/r as 4. In the range of parameters examined, the maximum enhancement in Nusselt number (Nu/Nu_s) is observed to be 1.35 at an optimal parameter of r/P_tv as 0.1, P_lg/r as 4, and Re as 10,200. Correspondingly, the enhancement in the friction factor (f/f_s) at this optimum parameter is 1.87. The maximum value of the THP parameter is found to be 1.1 at the same optimum range of parameters. In further analysis, correlations were developed for Nusselt number (Nu) and friction factor (f) in terms of r/P_tv, P_lg/r, and Re with a deviation of ±2% and ±1.5%, respectively.     

Use of tergitol-7 in photogalvanic cell for solar energy conversion and storage: Toluidine blue-glucose system

Photogalvanic effects were studied in a photogalvanic cell containing toluidine blue, glucose and tergitol-7 as a photosensitizer, reductant and surfactant, respectively. The photocurrent and photopotential generated by this system were 70 μA and 315 mV, respectively. The effects of different parameters on the electrical output of the cell were observed. Current/voltage characteristics of the cell have also been studied, and a mechanism has been proposed for the generation of photocurrent in photogalvanic cell.     

Influence of Soret and Dufour on mixed convection flow across a vertical cone

This contribution examines the influence of Soret and Dufour on an incompressible viscous fluid flow across a vertical cone. The flow model is framed in the form of mathematical governing equations and a nondimensionalization is performed on them for ease of the numerical computations' examination; the obtained nonsimilarity equations are solved numerically through the bivariate Chebyshev spectral collocation quasi-linearization method. Outcomes of the flow characteristics, velocity, temperature, concentration, skin friction rate, heat, and mass transfer rates are analyzed with the variations of governing parameters, Prandtl number, buoyancy parameter, Schmidt number, buoyancy ratio, Soret and Dufour parameters at various stream-wise spots of the flow. To certify the exactness of the listed computations, we performed a comparison with prior published computations, which were found with great agreement, and the residual analysis study was also portrayed to reflect the convergence and stability of the adopted numerical technique.     

Enhanced sunlight driven photocatalytic activity and electrochemical sensing properties of Ce-doped MnFe2O4 nano magnetic ferrites

This research deals with the facile combustion synthesis of manganese ferrite (MFO) nanoparticle with different cerium concentration and their potential application as an efficient photocatalyst and chemical sensor. The concentration of introduced cerium affects the size, structure, compositional, morphological, optical, photoluminescence and magnetic properties of the ferrite nanoparticle. The X-ray diffraction pattern affirmed the arrangement of cubic spinel structure with the formation of secondary phase CeO₂ as the cerium concentration exceed 3 mol%. SEM micrographs revealed irregular morphology with more number of pores and voids. HRTEM along with SAED pattern revealed the crystalline cubic nature. The optical band gap deduced from UV–Vis-DRS spectra was observed to be in the range 2.3–2.8 eV. PL studies indicated a significant minimization in combination of electrons & holes in MnFe₂O₄ on addition of Ce dopant. VSM investigation demonstrated the soft magnetic nature of the prepared sample with moderate magnetization value. An excellent photocatalytic performance of Cerium doped MFO (3 mol%) towards MB and AR dye degradation was found to be 1.5 and 1.67 times more compared to host matrix under Sunlight irradiation that correlated to reduced band gap, Ce dopant and efficient separation of charge carriers. Cerium doped MFO (3 mol%) have high specific capacitance value of 471.7 and 1546.8 Fg^-1 for NaNO₃ and HCl electrolytes respectively, indicating the pseudo capacitance nature due to which it can be used as a supercapacitor. The synthesized nanoparticles can sense d-Glucose and Paracetamol even at a lower concentration varying from 1 to 10 mM. The synthesized Ce-doped MnFe₂O₄ nanomaterials have great potential to be used in the future production of promising active photocatalysts and sensitive chemical sensors for the identification and degradation of toxic industrial dyes for improved safety in the fields of environment and health care.     

Correlation Based Feature Selection Algorithms for Varying Datasets of Different Dimensionality

Wireless Personal Communications - Curse of dimensionality problem needs to be addressed carefully when designing a classifier. Given a huge dimensional dataset, one interesting problem is the...     

Modelling Networks as Neighborly Irregular Graphs

Today’s world is filled with numerous computing devices and electronic gadgets connected to the Internet. These devices continuously sense and deliver their desired task autonomously or via owners. Domestic applications like healthcare monitoring systems, smart farming, noise pollution control, etc., involves many sensors and wearables that tirelessly estimate, evaluate and report the desired outcome. There are circumstances where two or more sensors at the same level, sense the same information and rely to the controller/base station. Handling and processing of such duplicate information results in increased overhead messages and reduced lifetime of sensors. This paper proposes a novel idea to model a network as a Neighborly Irregular graph so that optimal placement of sensor nodes can be guaranteed and communication between sensors at the same level is restricted. A simple and novel algorithm to construct Neighborly Irregular graph is proposed which converts the underlying network to a Neighborly Irregular graph if the network is not Neighborly Irregular. The proposed idea is tested with smart irrigation system in real time to prove its effectiveness. Experimental results prove that the message overheads are drastically reduced when the underlying network is Neighborly Irregular.

     

A New Supervised Clustering Framework Using Multi Discriminative Parts and Expectation–Maximization Approach for a Fine-Grained Animal Breed Classification (SC-MPEM)

Neural Processing Letters - Fine-grained image classification is active research in the field of computer vision. Specifically, animal breed classification is an arduous task due to the challenges...     

Design and Analysis of UWB Filter with Single Notch Band

Wireless Personal Communications - In this article, design and electrical analysis of UWB filter with a notch band is presented. Initially basic UWB filter is designed by using parallel coupled...     

Insight into nitric acid extraction and aggregation of N,N, N’, N’-Tetraoctyl diglycolamide (TODGA) in organic solutions by molecular dynamics simulation

The molecular dynamics (MD) simulation of TODGA in n-dodecane shows formation of nanostructures of TODGA aggregates with nitric acid and water. These aggregates are dispersed in dodecane phase or form well defined reverse micelles grown sufficient in size depending on the acid concentration. With increasing nitric acid concentration, aggregation number of TODGA in reverse micelles also increases which, however, is independent of TODGA concentration. Aggregation number rises from 2 to 8 in presence of 0–3.5 M nitric acid in corresponding aqueous phase. The formation of the aggregates explains remarkable acid co-extraction from aqueous phase to organic dodecane phase by TODGA.