Numerical Simulation of Double Diffusive Mixed Convection in a Horizontal Annulus with Finned Inner Cylinder

The present work relates to a numerical investigation of double diffusive mixed convection around a horizontal annulus with a finned inner cylinder.The solutal and thermal buoyancy forces are sustained by maintaining the inner and outer cylinders at uniform temperatures and concentrations.Buoyancy effects are also considered,with the Boussinesq approximation.The forced convection effect is induced by the outer cylinder rotating with an angular velocity(ω)in an anti-clockwise direction.The studies are made for various combinations of dimensionless numbers;buoyancy ratio number(N),Lewis number(Le),Richardson number(Ri)and Grashof number(Gr).The isotherms,isoconcentrations and streamlines as well as both average and local Nusselt and Sherwood numbers were studied.A finite volume scheme is adopted to solve the transport equations for continuity,momentum,energy and mass transfer.The results indicate that the use of fins on the inner cylinder with outer cylinder rotation,significantly improves the heat and mass transfer in the annulus.

Kinetic degradation of amoxicillin by using the electro-Fenton process in the presence of a graphite rods from used batteries

This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the electroFenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were investigated.The results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_(0)=0.082 mmol·L^( 1) and[Fe^(2+)]=1 mmol·L^(1),leading to 95%degradation and 74%mineralization.The model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudosecondorder kinetic.The Energy consumption(EC)calculated under the optimal values was found to be 0.79 kWhg 1,which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.

Modeling and Analysis of UAV-Assisted Mobile Network with Imperfect Beam Alignment

With the rapid development of emerging 5G and beyond(B5G),Unmanned Aerial Vehicles(UAVs)are increasingly important to improve the performance of dense cellular networks.As a conventional metric,coverage probability has been widely studied in communication systems due to the increasing density of users and complexity of the heterogeneous environment.In recent years,stochastic geometry has attracted more attention as a mathematical tool for modeling mobile network systems.In this paper,an analytical approach to the coverage probability analysis of UAV-assisted cellular networks with imperfect beam alignment has been proposed.An assumption was considered that all users are distributed according to Poisson Cluster Process(PCP)around base stations,in particular,Thomas Cluster Process(TCP).Using thismodel,the impact of beam alignment errors on the coverage probabilitywas investigated.Initially,the ProbabilityDensity Function(PDF)of directional antenna gain between the user and its serving base station was obtained.Then,association probability with each tier was achieved.A tractable expression was derived for coverage probability in both Line-of-Sight(LoS)andNon-Line-of-Sight(NLoS)condition links.Numerical results demonstrated that at low UAVs altitude,beam alignment errors significantly degrade coverage performance.Moreover,for a small cluster size,alignment errors do not necessarily affect the coverage performance.

Wave Functions for Time-Dependent Morse Potentials

The one dimensional Schrodinger equation associated with a time-dependent Morse potentials is studied. We use the invariant operator method （Lewis and Riesenfeld） to obtain approximate solution of the Schrodinger equation in terms of solution of second order ordinary differential equation describes the amplitude of the Morse potentials.

Electronic structure and magnetic properties of rare-earth perovskite gallates from first principles

The density functional calculation is performed for centrosymmetric（La–Pm） GaO3 rare earth gallates, using a full potential linear augmented plane wave method with the LSDA and LSDA＋U exchange correlation to treat highly correlated electrons due to the very localized 4f orbitals of rare earth elements, and explore the influence of U = 0.478 Ry on the magnetic phase stability and the densities of states. LSDA＋U calculation shows that the ferromagnetic（FM） state of RGaO3 is energetically more favorable than the anti-ferromagnetic（AFM） one, except for LaGaO3 where the NM state is the lowest in energy. The energy band gaps of RGaO3 are found to be in the range of 3.8–4.0 eV, indicating the semiconductor character with a large gap.

Electrosynthesis, Characterization and Electrocatalytic Behaviour of Organic-Metal Thin-Films Based on 2,2’-Bithiophene-5-carboxylic Acid and Metal Ions

2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These films were complexes with several metal ions such as Cu2+, Ag+ and Co2+. Their structural characteristics were compared with those of powder complexes chemically prepared from BTA and the corresponding metal ion. IR and XPS techniques reveal that the film complexes with metal ions have the same structures as the corresponding powder complexes. The electrocatalytic activity of BTA film-metal ions has been investigated toward ascorbic acid (AA) oxidation and compared to that obtained on a free BTA film. BTA film-metal ions exhibit good catalytic proprieties and better detection of AA than a free BTA film. This new propriety allows these films to be used as electrochemical sensors. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.

Experimental Analysis and Damage Modeling of High-Density Polyethylene under Fatigue Loading

In this study,an experimental analysis for determining the fatigue strength of HDPE-100 under cyclic loading is presented.The curve of cumulative fatigue damage versus number of cycles（D-N） was deduced from stiffness degradation.Based on the three stage damage trend,the remaining fatigue life is numerically predicted by considering a double term power damage accumulation model.This model is found to be accurate,both in modeling the rapid damage growth in the early life and near the end of the fatigue life.Numerical results illustrate that the proposed model is capable of accurately fitting several different sets of experimental data.

A comparative study of a direct and pulse electrodeposition method of TiO_(2)films and its effect on photoelectrocatalytic degradation of methyl orange dye

The present study reports the titanium dioxide(TiO_(2))films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques,namely direct electro-deposition(DE)and pulse electro-deposition(PE).The synthesis potential during the time-on(Ton)period was fixed at-1.5 V.However,the open-circuit potential was applied during the time-off(Toff)period.The effect of the technique of electro-deposition and Toff duration on the properties of TiO_(2)films and their photoelectron-catalytic activity were investigated.The obtained films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-VIS spectrometer,and photocurrent measurement respectively.It is found that the use of the PE technique at different Toff improves the properties of TiO_(2)films compared to the DE technique.The XRD patterns show the anatase phase with a marked preferential orientation along the(101)direction for all samples.From the SEM analysis,it is seen a significant change from big multigrain agglomerates at DE to a dense film structure and small multigrain agglomerates at different Toff.As the Toff decreases from 3 s to 1 s,the photocurrent response rises and reaches a high value of about 12 m A/cm^(2).Compared with DE,and under UV light the photocatalytic property of TiO_(2)film synthesis via PE has been improved in the degradation of methyl orange(MO).Finally,the films deposited at low Toff(Toff=1 s)show a faster degradation of MO.

A Novel Active Learning Method Using SVM for Text Classification

Support vector machines（SVMs） are a popular class of supervised learning algorithms, and are particularly applicable to large and high-dimensional classification problems. Like most machine learning methods for data classification and information retrieval, they require manually labeled data samples in the training stage. However, manual labeling is a time consuming and errorprone task. One possible solution to this issue is to exploit the large number of unlabeled samples that are easily accessible via the internet. This paper presents a novel active learning method for text categorization. The main objective of active learning is to reduce the labeling effort, without compromising the accuracy of classification, by intelligently selecting which samples should be labeled.The proposed method selects a batch of informative samples using the posterior probabilities provided by a set of multi-class SVM classifiers, and these samples are then manually labeled by an expert. Experimental results indicate that the proposed active learning method significantly reduces the labeling effort, while simultaneously enhancing the classification accuracy.

Morphology and Photoelectrochemical Characterization of MEH-PPV/PCBM Composite Film Doped with TiO_2 Nanoparticles

Poly[2-methoxy-5-（20-ethylhexyloxy）-io-phenylenevinylene] （MEH-PPV）, [6,6]-phenyl-C61-butyric acid methyl ester （PCBM） and titanium dioxide （TiO2） nanoparticles （n-type） were dissolved, mixed and deposited by physical methods （spin-coating） on indium tin-oxide （ITO） substrate. The incorporation of the titanium dioxide nanoparticles changed the morphology and increased the roughness of polymers film （MEH-PPV/PCBM）, and the photocurrent density of the composite （MEH-PPV/PCBM ＋n-TiO2） was higher than that of single MEH- PPV/PCBM film. The study showed that the presence of n-TiO2 particles in the polymeric film improves the photoelectrochemical properties of M EH-PPV/PCBM composite.