Evaluation of thin-layer models for describing drying kinetics of poplar wood particles in a fluidized bed dryer

In this study, fluidized bed drying experiments were conducted for poplar wood particles (Populus deltoides) at temperatures ranging from 90°C to 120°C and air velocities ranging from 2.8 m s^?1 to 3.3 m s^?1. The initial moisture content (MC) and the bed height of the poplar wood particles were 150% (on an oven-dry basis) and 2 cm, respectively. The results showed that the drying rate increased by increasing the drying temperature and air velocity. The constant drying rate period was only observed at the early stages of the drying process and most of the drying processes were found in the falling rate period. The experimental data of the drying process were put into e11 models. Among these models, Midilli, Kucuk, and Yapar (2002 Midilli, A., H. Kucuk, and Z. Yapar. 2002. A new model for single-layer drying. Drying Technology 20:1503–13. doi:10.1081/DRT-120005864[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) and Henderson and Pabis (1961 Henderson, S. M., and S. Pabis. 1961. Grain drying theory I. Temperature effect on drying coefficient. Journal of Agriculture Engineering Research 6 (3):169–74. [Google Scholar]) were found to satisfactorily describe the drying characteristics of poplar wood particles. The effective moisture diffusivity of wood particles increased from 7E-6 to 8.46E-6 and 7.65 E-6 to 1.44E-5 m² s^?1 as the drying air temperature increased from 90°C to 120°C for 2.8 m s^?1 and 3.3 m s^?1 of velocities, respectively. Also, the activation energies of diffusion were 34.08 kJ mol^?1 and 64.70 kJ mol^?1 for the air velocities of 2.8 m s^?1 and 3.3 m s^?1, respectively.     

Effect of rotationally restrained and Pasternak foundation on buckling of an orthotropic rectangular Mindlin plate

This article, based on first-order shear deformation theory, presents the buckling analysis of a rotationally restrained orthotropic rectangular Mindlin plate resting on a Pasternak elastic foundation. Thus, the Mindlin–Reissner plate theory is employed for which the governing equations are solved by the Rayleigh–Ritz method. Uniformly distributed in-plane loads are applied to two simply supported opposite edges of the plate and the other two edges have rotationally restrained conditions without loading. Finally, the effects of plate parameters, such as foundation stiffness coefficients, aspect ratios, and ratio of elastic modulus in the x to y direction on the buckling loads are presented. The results show that the buckling load would increase when the ratio of the elastic modulus in the x to y direction increases and the plate is close to isotropic. The variation of buckling load versus changing ratio of elastic modulus in the x to y direction in the state of without elastic foundation and with clamp support is more than the rest of the state.     

Postbuckling and deflection response of imperfect piezo-composite plates resting on elastic foundations under in-plane and lateral compression and electro-thermal loading

This article presents closed-form solution for the buckling, postbuckling, and nonlinear deflection of laminated composite plate with two piezoelectric actuators on elastic foundation and under transverse pressure, in-plane compression, thermal, and electrical loads for the first time in the literature. Material properties are assumed to be temperature-dependent. Two cases of boundary conditions and initial imperfection of the plate are considered. The formulations are based on the classical laminated plate theory (CLPT). The Galerkin method is employed to obtain load–deflection relations. The effects of elastic foundation, lateral pressure, in-plane compression, temperature dependency of material properties, electrical and thermal loading, imperfection, and aspect ratio are studied.     

Calculation of AC Magnetizing Loss of ReBCO Superconducting Tapes Subjected to Applied Distorted Magnetic Fields

In recent years, there are fast-increasing concerns on the utilizations of superconducting rotating electrical machines in different application areas, such as ship propulsion systems, aircraft drivers, and wind turbine generators, since these machines exhibit the merits of high current density, compact design, high power density, light weight, high torque density as well as high efficiency. One of the main limitations in front of the vast use of superconducting tapes in the fabrication of electrical machineries is AC magnetizing loss when tapes are exposed to an external magnetic field, which can decrease the critical current density of wires, as well. In the literature, most of the research works have been done on calculation of the AC magnetizing loss under a pure external magnetic field, while in reality, magnetic flux lines in AC electrical machines are usually distorted with harmonics because of different reasons such as distorted leakage flux, distributed coils of a winding in several slots, cogging fields, mechanical faults, etc. Since these distorted fields contain harmonics, then in this paper, the AC magnetizing loss of superconducting tapes has been electromagnetically modeled and calculated when they are subjected to nonsinusoidally distorted external magnetic fields. The magnetic field dependency of critical current density has been considered in a proposed finite element model. The results have shown that the AC magnetizing loss increases significantly under a distorted applied field compared with a sinusoidal one. In addition, the loss increase depends on the harmonic content which would increases drastically with total harmonic distortion of the applied magnetic field.     

New attacks on secret sharing-based data outsourcing: toward a resistant scheme

In this paper, two new practical attacks on some secret sharing-based data outsourcing schemes are first introduced, and several other security and performance issues with the existing schemes are also explored. The existing and new attacks exploit the information about the share range boundaries or the correspondences between the secret values and shares. A range expansion technique is then proposed to thwart one of the attacks. It expands the ranges in every range predicate in the submitted queries in order to hide the share range boundaries from any query observer. Next, a mapping method is proposed to thwart the other attacks. It maps each secret value to a mapping value using a secret one-to-many mapping with a finite set of linear mapping rules so that the tuples of shares are generated from the mapping values rather than directly from the secret values. The proposed mapping method works as an additional layer of security and addresses any attack based on the correspondences between the secret values and shares. At the same time, it preserves the homomorphism property of secret sharing. Finally, a new secure data outsourcing scheme is elaborated on secret sharing, the proposed mapping method, and the proposed range expansion technique. The proposed scheme is resistant to various attacks and also some inferences. It supports the fully server-side or a partially server-side query execution of most types of queries. The experimental results confirm that the proposed scheme is quite practical and efficient.

     

A flexible energy management approach for smart healthcare on the internet of patients (IoP)

Considering the importance of biosensors on the Internet of the patient body that collect vital signs and transmit them to the coordinator, energy consumption and network lifetime are essential challenges in these networks. This paper, it has been tried to present a method based on adapting sampling rate through patient’s risk and discovered pattern by employing an intelligence method based on adaptive neuro-fuzzy inference system, interpolation function, and a biosensor patron. It causes restricting sensed and transmitted data to the coordinator. In the proposed schema, three methods containing Grid partitioning, Subtractive Clustering and fuzzy c-means have been used in two modes, including hybrid and error backpropagation, to predict the individual’s behavioral pattern and determine the patient's risk, attentively. The simulation results in MATLAB R2018b show that the proposed method reduces the network communications. It has improved energy consumption by up to three times and also reduced traffic by more than 80% compared to similar methods.

     

Novel design and simulation of reversible ALU in quantum dot cellular automata

The Journal of Supercomputing - Quantum dot cellular automata (QCA) technology is considered as one of the most suitable replacements to reduce the CMOS-based digital circuit design problems at the...     

Joint optimisation of price,warranty and recovery planning in remanufacturing of used products under linear and non-linear demand,return and cost functions

We investigate joint optimisation of remanufacturing, pricing and warranty decision-making for end-of-life products. A novel mathematical–statistical model is proposed where decisions involve pricing of returned used products (cores), degree of their remanufacturing, selling price and the warranty period for the final remanufactured products. The virtual age reliability improvement approach is chosen to model the upgrading of the cores to higher quality levels. We consider price- and warranty-dependent demand, price- and age-dependent return, and age-dependent remanufacturing cost in the model development. Both linear and non-linear forms of these functions are investigated. First, under some restrictive conditions of upgrade level and age distribution of received cores, special cases of the problem, which can be solved using a recently developed non-linear optimisation solver, are presented. We also implement a particle swarm optimisation algorithm for the solution of the original problem when all the restrictive assumptions are dropped. Finally, numerical experiments and sensitivity analysis are presented to address different aspects of the model and the solution approaches.     

Active fuzzy modeling for estimating problems in hydrocarbon reservoirs

While active learning method (ALM) uses error as the learning parameter, selection of the validation data is still challenging. In this paper, to prevent form encountering with sample size problem, we applied an error-independent version of ALM that we call the active fuzzy modeling (AFM) with a distance threshold to model parameters of hydrocarbon reservoirs. In this paper, we demonstrate that measuring the generalization error is a vital factor in the process of ALM. Regression (R) and mean squared error (MSE) for estimating RHOB by AFM were 0.96 and 0.0032, respectively. On the other hand, R of 0.91, 0.89 and 0.92 and MSE of 0.0051, 0.0067 and 0.0047 for ANN, TS-FIS and NF, respectively, illustrate that AFM performs much better in comparison with conventional modeling approaches and produces more reliable results. Comparing the results of the presented method with ANN, TS-FIS and NF in aspect of rapidity, robustness, storage, complexity and acceptability in estimating RHOB reports the accuracy and high-performance behavior of AFM. This method is illustrated by an example of an oil field at NW Persian Gulf.