An experimental study of the effect of pin fins on heat transfer in circulating fluidized beds

An experimental investigation was conducted to study the effect of pin fins on heat transfer in circulating fluidized beds. Experiments were conducted in a 100 mm i.d., 5.15 m tall CFB unit, initially with no fins and then with 16-pin and 32-pin fins. Each pin was 6.35 mm in diameter and 15 mm long. It was observed that, although the heat transfer coefficient decreases with the use of fins, the total heat transfer increases owing to the increase in surface area which the fins provide. The results of heat transfer for unfinned surface were compared with those of other workers and found to be in good agreement.     

A novel scheme to detect the best cloud service provider using logarithmic operational law in generalized spherical fuzzy environment

Knowledge and Information Systems - Generalized spherical fuzzy number (GSFN) is an extension of spherical fuzzy number (SFN) which deals the uncertainties involved in the real-life problems in...     

Synergistic Effects of Polybenzimidazole and Aramide on Enhancing Flame-Retardancy and Solubility

Aromatic and functional polymers with processibility derived from biobased starting materials are prerequisite considering sustainable society. Poly(2,5-benzimidazole)s are rigid-rod polymers to show ultrahigh thermal stability such as flame retardance, while usually suffer from poor solubility. Here, poly(benzimidazole-co-amide)s are synthesized from two biobased monomers, 3,4-diaminobenzoic acid and a semirigid comonomer, 4-aminohydrocinnamic acid. The copolymers with an amide composition of 80 mol% and higher are soluble in widely used polar solvents to fabricate the films keeping high flame retardance, which is comparable with popular high-performance polymers such as aromatic polyimides, polyetheretherketone, polyphenylene sulfide, etc.     

Effects of Silicon on Growth,Yield and Fruit Quality of Cantaloupe under Drought Stress

Silicon - Silicon (Si) plays an important role in mitigating adverse effects of various biotic and abiotic stresses including drought. Polyhouse experiment was conducted to evaluate the effects of...     

Influence of morphology and surface characteristics on the photocatalytic activity of rutile titania nanocrystals

This article presents the synthesis of phase-pure rutile titania with different morphologies via hydrothermal method at significantly low temperatures (40-150 °C) without any additives and their application as efficient photocatalyst for environmental remediation. Phase and morphology has been determined with X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ultra violet diffuse reflectance spectroscopy (UV-DRS) shows the optical band-gap in the range of ∼2.8-3.1 eV and Brunauer-Emmett-Teller specific surface area is found to be between 70 and 140 m²/g depending on the synthesis conditions. Raman spectroscopic analyses of the samples provide valuable insights into the structural and stoichiometric details. Photodegradation of the pollutant azo-dye, methyl orange (MO) in presence and absence of oxygen was performed to study the photocatalytic efficiency of the synthesized materials. Complete photodegradation of the dye is confirmed with high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) study. Dependence of dye photodegradation rate on morphology, specific surface area, surface nonstoichiometry and acidity were investigated in detail. Catalyst performance was compared from the rate constants obtained for each reaction using non-linear least square fitting (NLSF) to the experimental data in a concentration ratio (C₀/C_t) versus time (t) plot which shows extraordinarily high activity for all samples compared to commercial reference. Among them the catalyst synthesized at 40 °C for 16 h showed best activity. Kinetic study of the reaction matches well with simulated fit to experimental data and confirms to be pseudo-first order reaction.     

An efficient verifiable (t,n)-threshold secret image sharing scheme with ultralight shares

Multimedia Tools and Applications - A secret sharing scheme partitions a secret into a set of shares and distributes them among the eligible participants, with each participant receiving one share...     

An optimal linear and elliptical antenna array design using black widow optimisation for 5G communication

This research illustrates a precise linear and elliptical antenna array design for synthesising the optimal far-field radiation pattern in the fifth-generation (5G) communication spectrum using a meta-heuristic optimisation technique known as black widow optimisation (BWO). 5G communication is an emerging technology with revolutionary changes in the wireless communication system with ultra-high data rate, enhanced capacity, low latency and good quality of service. An accurate antenna array design for an ideal far-field radiation pattern synthesis with a suppressed side lobe level (SLL) value and half power beam width (HPBW) is the most crucial aspect of 5G communications. A suppressed SLL is necessary to reduce interference in the entire side lobe region, whereas a low HPBW is required for long-distance communication. Here, the BWO is employed to find the optimal feeding current to each array element to lower the SLL and the HPBW value. The BWO algorithm sustains impeccable equity between the exploration and exploitation stages to impact different potential regions of the search space and generate new solutions to attain the global optima by evading the trap of local optima. The design examples of the linear antenna array (LAA) and elliptical antenna array (EAA) are illustrated in this article by applying the optimal feeding currents to each array element. Compared to the uniform antenna array and methodologies described in the recently published literature, the results obtained utilising the BWO algorithm for designing the LAAs and EAAs demonstrate a substantial development in the reduction of SLL and HPBW.     

Removal of Pb(II) ions from aqueous solution by adsorption using bael leaves (Aegle marmelos)

Biosorption of Pb(II) on bael leaves (Aegle marmelos) was investigated for the removal of Pb(II) from aqueous solution using different doses of adsorbent, initial pH, and contact time. The maximum Pb loading capacity of the bael leaves was 104 mg g^?1 at 50 mg L^?1 initial Pb(II) concentration at pH 5.1. SEM and FT-IR studies indicated that the adsorption of Pb(II) occurs inside the wall of the hollow tubes present in the bael leaves and carboxylic acid, thioester and sulphonamide groups are involved in the process. The sorption process was best described by pseudo second order kinetics. Among Freundlich and Langmuir isotherms, the latter had a better fit with the experimental data. The activation energy E_a confirmed that the nature of adsorption was physisorption. Bael leaves can selectively remove Pb(II) in the presence of other metal ions. This was demonstrated by removing Pb from the effluent of exhausted batteries.