This paper proposes an optimal tuning of fractional order proportional integral derivative (FOPID) controller for higher order process using hybrid approach. The proposed hybrid approach is the joint ...execution of Dynamic Differential Annealed Optimization (DDAO) and Feedback Artificial tree (FAT) algorithm, hence it is named D2AOFAT approach. The FOPID controller parameters like
k
p
,
k
i
,
k
d
, λ
and
μ
. The FOPID controller parameters errors are minimized and predict the optimal parameters by the FAT algorithm. Based on FOPID controller parameters using FAT algorithm, the DDAO optimizes the FOPID controller parameters. The FOPID controller advantage is adjusted to accomplish that needed responses that are resolute with FAT theory and RDF parameters are predictable using DDAO technique. The purpose of the proposed control system is selected in light of the achieved parameters of time delay system (TDS). The proposed technique is carried out in MATLAB / Simulink, its performance is compared to the existing techniques, like Ziegler-Nichols fit, Curve Fit, Wang method, and IWLQR method.
•Polycrystals of Magnetic Superconductor Pr2Pt3Ge5 has been prepared.•Mixed state has studied via TAFF & mod. TAFF model of vortices.•Vortex Glass state has been observed in this magnetic ...superconductor.•Tendency towards 2D nature of superconductivity has been found.•Non-Fermi liquid behavior has been found in normal state.
A comprehensive study on a magnetic superconductor (Pr2Pt3Ge5) has been presented here. Superconducting state is well described through modified model of thermally activated flux flow (TAFF) motion of vortices which shows that consideration of temperature dependence of the prefactor as well as non-linear variation of thermally activated energy (TAE) of vortices provides more reliable value of TAE in different fields. A clear signature of vortex glass (VG) state in this superconductor has been observed with a crossover from 3-dimensional (3D) to 2-dimensional (2D) critical behaviour in field. In addition, the dimensionality analysis using different models like modified TAFF, obtained critical exponent (s) from VG state and Lowest Landau Level (LLL) scaling reveals that Pr2Pt3Ge5 has a tendency towards 2D behaviour. Moreover, normal state study shows a clear signature of non-Fermi liquid (NFL) behaviour in this superconductor which shifts to Fermi liquid (FL) state at higher fields.
Analysis of the resistivity, thermoelectric power, and heat capacity of Fe1−xNixSi is presented in this report. In-spite of Ni having two extra valence electrons as compared to Fe, the physical ...properties are observed to be dominated by holes. In this report, we have explained this unusual hole dominant scenario by a modified two narrow-band model. According to this model, the impurity electrons which are nearer to conduction band get shifted towards lower energy level thereby leaving holes around the Fermi level, and hence a hole dominated scenario at low temperatures. Due to this hole like density of states around the Fermi level, the nickel substitution could only produce a weak ferromagnetic behavior. Such a picture may assist in understanding the thermopower of similar systems i.e. Ni substituted on Fe site, such as Fe2−xNixVAl. We have also found that the activation energy derived from resistivity and thermoelectric power decreases with increasing Ni concentration.
This manuscript proposes an optimum design based state feedback gain of fractional order proportional integral derivative (FOPID) controller for time delay system (TDS). The proposed optimum design ...is the consolidation of Northern Bald ibis optimization algorithm (NOA) and Radial Basis Function Neural Network (RBFNN) controller, hence it is called NOARBFN. Here, the three tuning parameters (
K
P
,
K
i
,
K
d
) consists of two additional tuning parameters like
λ
and
µ
is considered. NOARBFN is utilized for tuning 3 controller parameters, moreover detect the optimum values of
λ
as well as
µ
. The individuality of NOARBFN technique is the faults of FOPID controller in higher order TDS that is minimized with the help of controller’s incremental limitations. The objective of NOARBFN technique is to consider the set point parameters and accomplished parameters from TDS. The proposed NOARBFN method is utilized to mitigate high-order delays and reliable constraints like small over runs, time resolution, fixed state defect. The proposed method is executed in MATLAB/Simulink site and the performance is analyzed with other existing methods.
The Periconium sp. extract mediated sol-gel process was effectively utilized for the synthesis of ZnO nanoparticles. The aqueous fungal extract acted as chelating agent for the Zn2+ ions and lead to ...the formation of gel. The dried gel was characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Thermogravimetric/differential thermal analysis (TG/DTA) respectively to identify their phase, structural coordination, morphological feature and thermal degradation profile. The XRD analysis reveals that the biosynthesized ZnO nanoparticles are exist in hexagonal wurtzite structure with the average crystallite size of 40 nm. Transmission electron microscopic (TEM) images of the synthesized ZnO nanoparticles did show the quasi spherical shape with 16–78 nm in size. The Dynamic Light Scattering (DLS) analysis showed their zeta potential and hydrodynamic particle size respectively as −88.6 mV and 338 nm. The UV–Visible spectroscopic analysis depicts their band gap energy as 3.15 eV. The synthesized ZnO nanoparticles exhibited excellent antimicrobial activity against Staphylococcus aureus (Gram positive), Escherichia coli (Gram negative) and Candida albicans (fungi) with an average inhibition zone of 16, 14 and 24 mm, minimum inhibitory concentration (MIC) value of 50, 50, 40 μg/ml, the minimum bactericidal/fungicidal concentration (MBC/MFC) of 50 μg/ml and the half maximal inhibitory concentration (IC50) of 22, 38 and 21 μg/ml respectively. Further, the ZnO nanoparticles also exhibited good antioxidant property with the 85.52% free radical quenching for 100 μg/ml concentration.
•Annealing-induced change in optical parameters of CdTe film was derived from UV–vis study.•Optical constants of the films were evaluated using Swanepoel method.•Dispersion energy data obeyed the ...single oscillator of the Wemple−Didomenico model.•Cd deficiency of the film confirmed the p-type conductive nature.
In this work, we report on post-deposition heat treatment (annealing)-induced change in optical properties derived from UV–vis study of CdTe thin films prepared on amorphous glass substrate by electron beam evaporation technique. Annealing effect gives rise to the enhancement in crystalline nature (zinc blende structure) of CdTe films with (111) preferred orientation. The average transmittance was increased with the annealing temperature and the slight shift in transmission threshold towards higher wavelength region revealed the systematic reduction in optical energy band gap. The existence of shallow level just below the conduction band, within the band gap was identified in the range of 0.23 and 0.14eV for the films annealed at 200 and 450°C, respectively. The optical quality of deposited films was confirmed by the photoluminescence study. In addition, the scanning electron microscopic measurement supports the result of X-ray diffraction study. The Swanepoel, Hervé-Vandamme, and Wemple−DiDomenico models have been employed to evaluate the various optical parameters of CdTe films. These results are correlated well with other physical properties and discussed with the possible concepts underlying the phenomena.
This paper presents the computational fluid dynamics (CFD) modeling to study the effect of fuel injection timing and intake pressure (naturally aspirated as well as supercharged condition) on the ...performance of a direct injection (DI) diesel engine. The performance characteristics of the engine are investigated under transient conditions. A single cylinder direct injection diesel engine with two directed intake ports whose outlet is tangential to the wall of the cylinder and two exhaust ports has been taken up for the study. Effect of injection timing (start of injection 16, 12 and 8 CAD bTDC) and intake pressure (1.01, 1.21 and 1.71
bar) on the performance of the engine has been investigated for an engine speed of 1000
rpm. CFD predicted results during both suction and compression strokes under motoring conditions have been validated with experimental results available in the literature. Magnusson’s eddy break-up model is used for combustion simulation. Predicted performance and emission characteristics such as pressure, temperature, heat release, NO
x
, and soot are presented and discussed. The predicted values reveal that retarding the injection timing results in increase in-cylinder pressure, temperature, heat release rate, cumulative heat release and NO
x
emissions. Decreasing trend is observed by advancing the injection timing. In case of soot emission the increasing trend is observed up to certain crank angle then reverse trend is seen. The supercharged with inter-cooled cases show lower peak heat release rate and maximum cumulative heat release, shorter ignition delay, higher NO
x
and lower soot emissions.
Manganese telluride is a good thermoelectric material for medium temperature applications. Pristine MnTe is a p-type semiconductor with an average hole concentration of 1019cm−3. Many dopants like ...Sodium, Copper and Sulphur were incorporated in the MnTe and their thermoelectric properties were studied. Antimony is an ideal dopant to alter the thermoelectric properties. Compounds belonging to the series Mn1−xSbxTe with (x = 0, 0.005, 0.01, 0.015, 0.02) were prepared using a combination of High Energy Ball Milling (HEBM), melt quenching and hot press techniques. Structural, electrical and thermo-electric properties of these compounds were determined. Carrier concentration and mobility were measured by Hall measurement techniques. Charge carrier concentration increases with Sb doping while mobility and effective mass decreases. Seebeck coefficient and electrical conductivity were measured in the temperature range 100 K–730 K, and thermal conductivity was evaluated in the temperature range 100 K–300 K. The power factor and figure of merit (ZT) were also estimated. The highest power factor achieved is at 730 K and is 1768μWm−1K−2 for Mn0.98Sb0.02Te. The highlight of the present study is the rise in electrical conductivity and reduction in the thermal conductivity with Sb doping.
•The p-type thermoelectric materials, Mn 1-x Sb x Te alloys, were prepared.•The electrical transport properties have been improved by the optimized carrier concentration by Sb doping.•The lattice thermal conductivity has been reduced due to the introduction of Sb.•Power factor values enhances by Sb doping.
The need for nutritional sources safer than traditional animal products has renewed interest generally in plants and particularly in microalgae. Microalgae have diverse uses in aquaculture, their ...applications are mainly to provide nutrition and to enhance the colour of the flesh of salmonids. The larvae of molluscs, echinoderms and crustaceans as well as some fish larvae feed on microalgae. Several studies have confirmed that a live multi-specific, low bacterial and microalgal biomass remains essential for shellfish hatcheries. Major advances are expected from new production system, designs and operations from batch run open tanks to more sophisticated continuously-run and closed loop reactors. Currently, studies are underway to examine the cost-effectiveness of the on- and off-site microalgal production systems which can only be achieved by substantial scaling-up and improved quality control. In order to attain sustainability in the usage of microalgae, a systems-based approach is required which integrates different fields such as biotechnology, bioprocess and management procedures.
