Structure and properties of CrN coatings formed using cathodic arc evaporation in stationary system

CrN coatings were deposited using cathodic arc evaporation in stationary system on the substrate surface faced to the plasma source and on the back surface.The effect of nitrogen pressure on the structure and phase composition,mechanical and tribological properties of the coatings was investigated.The coating morphology and structure were characterized using SEM and contact profilometry and X-ray diffractometry,respectively.Mechanical properties were studied by nanoindentation.The friction and wear properties of the coatings were investigated by ball-on-disk tribometer.An increase in nitrogen pressure during coating deposition results in phase transformation according to the relation Cr2N→Cr2N+CrN→CrN.The roughness of the coatings deposited on the front side of the substrate is higher than that on the back side,mainly due to larger number of macroparticles.The hardness and elastic modulus are also higher on the front side of the substrate.The adhesion and wear rate of the coatings have an inverse relationship.

Synthesis and study the influence of yttrium doping on band structure,optical,non-linear optical and dielectric results for Ca_(12)Al_(14)O_(33) (C12A7) single crystals grown using traveling-solvent floating zone (TSFZ) method

Ca_(12)Al_(14)O_(33)(C12A7)and Y_(0.02)Ca_(11.98)Al_(14)O_(33)(Y-C12A7)single crystals were grown by using the traveling-solvent floating zone(TSFZ)method.The temperature was increased to avoid the bubbles and cracks which may be formed during the preparation of the ingot material.We have started with the flux higher than the normal to avoid the bubbles and make good treatment for the solid-liquid interface.The structures of both Ca_(12)Al_(14)O_(33)(C12A7)and Y_(0.02)Ca_(11.98)Al_(14)O_(33)(Y-C12A7)were studied by using x-ray diffraction(XRD).Optical properties for C12A7 and Y-C12A7 single crystals have been studied in order to determine the optical parameters such as optical energy gap(Eg),refractive index n,oscillating energy(Eo),dispersion energy(Ed),volume energy loss function(VELF),and surface energy loss function(SELF).Finally,a new result for these samples is that the third-order nonlinear optical susceptibility(χ(3))was determined.The results have been discussed with effect of Y-doping on the C12A7 single crystals for optical and industrial applications.

Employing adaptive fuzzy computing for RCP intelligent control and fault diagnosis

Loss of coolant accident(LOCA),loss of fluid accident(LOFA),and loss of vacuum accident(LOVA)are the most severe accidents that can occur in nuclear power reactors(NPRs).These accidents occur when the reactor loses its cooling media,leading to uncontrolled chain reactions akin to a nuclear bomb.This article is focused on exploring methods to prevent such accidents and ensure that the reactor cooling system remains fully controlled.The reactor coolant pump(RCP)has a pivotal role in facilitating heat exchange between the primary cycle,which is connected to the reactor core,and the secondary cycle associated with the steam generator.Furthermore,the RCP is integral to preventing catastrophic events such as LOCA,LOFA,and LOVA accidents.In this study,we discuss the most critical aspects related to the RCP,specifically focusing on RCP control and RCP fault diagnosis.The AI-based adaptive fuzzy method is used to regulate the RCP’s speed and torque,whereas the neural fault diagnosis system(NFDS)is implemented for alarm signaling and fault diagnosis in nuclear reactors.To address the limitations of linguistic and statistical intelligence approaches,an integration of the statistical approach with fuzzy logic has been proposed.This integrated system leverages the strengths of both methods.Adaptive fuzzy control was applied to the VVER 1200 NPR-RCP induction motor,and the NFDS was implemented on the Kori-2 NPR-RCP.

Efficient Data Compression of ECG Signal Based on Modified Discrete Cosine Transform

This paper introduced an efficient compression technique that uses the compressive sensing(CS)method to obtain and recover sparse electrocardiography(ECG)signals.The recovery of the signal can be achieved by using sampling rates lower than the Nyquist frequency.A novel analysis was proposed in this paper.To apply CS on ECG signal,the first step is to generate a sparse signal,which can be obtained using Modified Discrete Cosine Transform(MDCT)on the given ECGsignal.This transformation is a promising key for other transformations used in this search domain and can be considered as the main contribution of this paper.A small number of wavelet components can describe the ECG signal as related work to obtain a sparse ECGsignal.Asensing technique for ECGsignal compression,which is a novel area of research,is proposed.ECG signals are introduced randomly between any successive beats of the heart.MIT-BIH database can be represented as the experimental database in this domain of research.TheMIT-BIH database consists of various ECG signals involving a patient and standard ECG signals.MATLAB can be considered as the simulation tool used in this work.The proposed method’s uniqueness was inspired by the compression ratio(CR)and achieved by MDCT.The performance measurement of the recovered signal was done by calculating the percentage root mean difference(PRD),mean square error(MSE),and peak signal to noise ratio(PSNR)besides the calculation of CR.Finally,the simulation results indicated that this work is one of the most important works in ECG signal compression.

Improved Control in Single Phase Inverter Grid-Tied PV System Using Modified PQ Theory

Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic(PV)grid-connected systems diversified.This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total har-monic distortion(THD)even under nonlinear load applications by improving its control scheme.The proposed system is expected to operate in both stand-alone mode and grid-connected mode.In stand-alone mode,the proposed controller supplies power to critical loads,alternatively during grid-connected mode provide excess energy to the utility.A modified variable step incremental conductance(VS-InCond)algorithm is designed to extract maximum power from PV.Whereas the proposed inverter controller is achieved by using a modified PQ theory with double-band hysteresis current controller(PQ-DBHCC)to produce a reference current based on a decomposition of a single-phase load current.The nonlinear rectifier loads often create significant distortion in the output voltage of single-phase inverters,due to excessive current harmonics in the grid.Therefore,the proposed method generates a close-loop reference current for the switching scheme,hence,minimizing the inverter voltage distortion caused by the excessive grid current harmonics.The simulation findings suggest the proposed control technique can effectively yield more than 97%of power conversion efficiency while suppressing the grid current THD by less than 2%and maintaining the unity power factor at the grid side.The efficacy of the proposed controller is simulated using MATLAB/Simulink.

Fabrication of PMMA nanocomposite biomaterials reinforced by cellulose nanocrystals extracted from rice husk for dental applications

The primary objective of global studies is to develop the properties and durability of polymers for various applications.When it comes to dental disability,denture base materials must have sufficient mechanical and tribological performance in order to withstand the forces experienced in the mouth.This work aims to investigate the effects of the addition of low content of cellulose nanocrystals(CNC)on the mechanical and tribological performance of the polymethyl methacrylate(PMMA)nanocomposites.Different weight percent of CNC(0,0.2,0.4,0.6,and 0.8 wt%)were added to the PMMA matrix followed by ball milling to evenly distribute the nanoparticles reinforced phase in the matrix phase.The findings emphasize the significant impact of CNC integration on the performance of PMMA nanocomposites.By increasing the content of the CNC nanoparticles,the mechanical properties of PMMA were improved.In addition,the tribological outcomes demonstrated a significant reduction in the friction coefficient besides an enhancement in the wear resistance as the weight percentage of nanoparticles increased.The surface of the worn samples was investigated by utilizing SEM to identify the wear mechanisms corresponding to the different compositions.In addition,a finite elment model(FEM)was developed to ascertain the thickness of the worn layer and the generated stressed on the surfaces of the nanocomposite throughout the friction process.

Secure Audio Transmission Over Wireless Uncorrelated Rayleigh Fading Channel

Audio communications and computer networking play essential roles in our daily lives,including many domains with different scopes.Developments in these technologies are quick.In consequence,there is a dire need to secure these technologies up to date.This paper presents an efficient model for secure audio signal transmission over the wireless noisy uncorrelated Rayleigh fading channel.Also,the performance of the utilized multiple secret keys-based audio cryptosystem is analyzed in different transformation domains.The discrete cosine transform(DCT),the discrete sine transform(DST),and the discrete wavelet transform(DWT)are investigated in the utilizedmultiple secret key-based audio cryptosystem.Simulation results show consistent results with the wireless noisy channel.The performance of the proposed multiple secret keys-based audio cryptosystem can be ranked concerning the employed domain as DWT,DCT,and DST transform techniques.The simulation experiments proved that the presented multiple secret keysbased audio cryptosystemfor audio signals transmitted over the wireless noisy uncorrelatedRayleigh fading channel achieves reliable and secure wireless link utilizing combined multi security layers.

A Quantum Algorithm for Evaluating the Hamming Distance

We present a novel quantum algorithm to evaluate the hamming distance between two unknown oracles via measuring the degree of entanglement between two ancillary qubits.In particular,we use the power of the entanglement degree based quantum computing model that preserves at most the locality of interactions within the quantum model structure.This model uses one of two techniques to retrieve the solution of a quantum computing problem at hand.In the first technique,the solution of the problem is obtained based on whether there is an entanglement between the two ancillary qubits or not.In the second,the solution of the quantum computing problem is obtained as a function in the concurrence value,and the number of states that can be generated from the Boolean variables.The proposed algorithm receives two oracles,each oracle represents an unknown Boolean function,then it measures the hamming distance between these two oracles.The hamming distance is evaluated based on the second technique.It is shown that the proposed algorithm provides exponential speedup compared with the classical counterpart for Boolean functions that have large numbers of Boolean variables.The proposed algorithm is explained via a case study.Finally,employing recently developed experimental techniques,the proposed algorithm has been verified using IBM’s quantum computer simulator.