bluuebunny/crossref_metadata_2025 huggingface dataset:
DCAECSCS: Divide and Conquer Algorithm Based Electro Cardiac Signal Compression Scheme
Authors: Bachu Srinivas , Shalini Thelapolu , Udaya Kumar Naluguru
Published: March 2021

The method of recording heart electrical activity over a period of time using electrodes implanted in the skin is referred to as electrocardiography (ECG). In constant patient monitoring, vast volumes of ECG data need to be treated. Therefore, when each time we need to track the patient’s heart condition, we have to store more details. It is very costly, however, to store, transfer and allocate bandwidth to this Meta data. Here, an effective compression technique has been applied to solve this problem in such a way that all the salient features that have been clinically needed can be preserved. We used the MIT-BIH ECG data database to validate the ECG.
Ecg Arrhythmia Signals Classification Using Particle Swarm Optimization-Support Vector Machines Optimized With Independent Component Analysis
Authors: Ramkumar M. , Ganesh Babu C. , Priyanka G.S. , Sarath Kumar R.
Published: March 2021

Cardiac Arrhythmia is one of the serious disorders which are most commonly found among humans larger in number. This study is based on proposing a novel approach for heart (Cardiac) arrhythmia disease classification. Many Machine learning algorithms are implemented for the cardiac arrhythmia classification from which the ECG signal are extracted from MIT-BIH Database. The main objective of this study is to do the classification of ECG signals to the normal and abnormal (Ventricular Tachycardia) category using PSO-SVM optimized with Independent Component Analysis using Genetic Algorithm. The extraction of ECG signal is done with twenty four features consisting of Normal and Abnormal clinical clusters. ECG Signals under these categories are extracted from MIT-BIH Arrhythmia database which is read in terms of P,Q,R,S and T voltage-time parametric signal. Genetic Algorithm and Particle Swarm Optimization together used to enhance the performance of the Support Vector Machine (SVM) classifier. Initially the SVM Classifier is designed and it is optimized by searching for the best parametric value where the discriminate function is tuned to extract the features under the best subsets and as a result the fitness functions which are classified are identified with better optimization. Additionally the PSO-SVM Classifier is allowed to undergo the adaptive mechanism wherein which the optimization factor is allowed to restrict the boundaries of classification of ECG arrhythmia with maximum accuracy by the implementation of Independent Component Analysis Optimization using Genetic Algorithm. The results are experimentally demonstrated with the comparison of PCA, ICA, PSO-SVM with ICA and G-ICA. Sensitivity, Specificity, False Positive Rate, True Positive Rate and Accuracy are the experimental parameters used for the performance metrics comparison to classify for normal and diabetic clinical condition. The parameters yield better results for PSO-SVM-ICA and G-ICA with respect to the above mentioned metrics. The Classification Accuracy is attained with 96% with best optimization strategies by using these hybrid classifiers.
RETRACTED: ResNet:A convolutional Neural Network for detecting and diagnosing of coronavirus pneumonia
Authors: Angeline R. , Vani R.
Published: March 2021

In this paper, ResNet a Convolutional Neural Network for detecting and diagnosing the lung disease Covid-19 pneumonia infection automatically. For identifying, Chest X-rays are widely used for diagnosis of pneumonia disease which affects the lungs. This paper provides an approach to detect and diagnose Covid-19 pneumonia and classify the chest X-ray images into two classes either Covid-19 pneumonia or normal utilizing CNN. This is done by training the CNN to differentiate between the normal and pneumonia chest X-ray images using a deep learning platform Pytorch. Image preprocessing technique has been applied in order to enhance the image accuracy. Python and OpenCV have been used.
Wavelet Region implanting watermark upgrades the security framework in Digital Speech Watermarking
Authors: China Venkateswarlu S. , Udaya Kumar Naluguru , Karthik Annam
Published: March 2021

The progressions in innovation helped us to use biometric characteristics to verify the people without having them physically. To limit unapproved people and to encourage approved people different human characteristics are used. Face, unique marks, retina, iris, and DNA are some of the biometrics which is used most often to identify people. For additional security in-person authentication and identification systems, a combination of this biometrics can be utilized. Voice can also be used as a biometric similar to other biometrics. Special equipment and computer systems are required to separate this biometrics. This work helps to enhance security by upgrading the modules and embedding the watermark in the speech signal, in-person verification systems. Speakers are validated based on the watermark present in the speech signal. Energy calculations are performed for detail coefficients to select the coefficients where the watermark has to be implanted. The coefficients with less energy are selected for watermark embedding. Inverse discrete transform is applied on approximation and detail coefficients to produce the watermarked speech. The exhibition of the work is assessed by utilizing the subjective and objective measurements such as peak signal to noise ratio, bit error rate, and perceptual evaluation of speech quality. Peak signal to noise ratio is calculated between unique watermark and separated watermark and, unique and watermarked speech. An arrangement of speech articulations of the speaker during the training stage is used to develop the models for the person authentication system. During testing, structures are removed after original and watermarked speech articulations and are used towards calculate the correctness of the system.
Usage of Particle Swarm Optimization to Improve the Performance of Supervised Classifiers
Authors: Bharanidharan N , Nivetha M , Balakrishna A , Dhanaraju P
Published: March 2021

Representing the data appropriately will have a significant effect on the outcome produced by the classifier. Transforming the feature will help to represent the data points in a more suitable way for the classifier. Particle swarm optimization belongs to the Swarm Optimization techniques category and it is generally used for solving numerical optimization problems, weight updation in neural networks, and feature selection. This research work proposes a Particle swarm optimization-based transformation technique for increasing the classification metrics of popular classification algorithms namely K-Nearest Neighbor, Stochastic Gradient Descent Classifier, Decision trees, and linear discriminant analysis classifier. Experiments are conducted using the SONAR dataset and the highest accuracy of 82.69% is attained for Stochastic Gradient Descent classifier when Particle swarm optimization is used as a transformation technique
Digital Watermarking For Medical Images Using Dwt And Svd Technique
Authors: Pravin Savaridass M , Deepika R , Aarnika R , Maniraj V , Gokilanandhi P , Kowsika K
Published: March 2021

In the modern world with developing technologies, all the information are collected and stored digitally. In medical field also the diagnostic information are recorded digitally and transmitted. While transferring the information digitally, security and authenticity is the main aspect to be concentrated. Watermarking is the technology which ensures the authenticity and security of the medical images, information about patient and diagnostic details. In this paper, hybrid watermarking technique by the combination of Discrete Wavelet Transform and Singular Value Decomposition is implemented, because of its high security and efficiency as compared with other frequency domain watermarking. The images have been tested against attacks like salt and pepper noise, Gaussian noise, and filtering attack. Efficiency and performance of this hybrid technique are evaluated based on PSNR, SSIM and NC. From the simulation results, PSNR is above 37 dB, which ensures better imperceptibility and shows better robustness with NC values near to 1 against image attacks during transmission.
A REVIEW ON NATURAL LANGUAGE PROCESSING Report: Statistics and Facts
Authors: Dinesh PM , Hariraj Kumar J. , Chandra Sekar S , Swarnambiga M. , Ranjani S.
Published: March 2021

NLP is a branch of AI, mainframe Knowledge and so on. It computes to program, process and analyze the huge amount of text, speech, and data. In this paper, we reviewed the different methodology used in NLP and the techniques used in different papers are different from another with a good accuracy and our paper helps to know about the methodologies in NLP and helps to find the methodology for required application and it precisely according to the user need.
Optimization of Beamforming in Subarray Antennas Using Firefly Algorithm
Authors: Raju C. , Ramkumar Raja M. , Mano Raja Paul M. , Leeban Moses M.
Published: March 2021

The subarray antenna techniques are much focused for flexible beamforming in envisioned smart antenna applications. The aim of this subarray arrangement of antenna elements is greatly motivated by bandwidth enhancement and interference minimization in the upcoming 5G next generation networks infrastructure. The optimization is required for effective placement of nulls in the desired direction of interferes from known sensed and verified disturbance angles. In this three dimensional radiation pattern optimization, the number of phase shift elements and constructive values for pointing focused beam and destructive strength in the obstacles is crucial. In this paper we proposed a firefly algorithm for dynamic management of the radiation pattern. It is possible with the optimization of the weight parameters of the subarray antenna. From the given Direction of Arrival we investigate the possibilities of deep placing of nulls is simulated and analyzed with the antenna parameters.
Design And Implementation Of Amba Apb Protocol
Authors: Mukunthan J , Daniel Raj A , Keerthivadana S , Kiruthika R , Shruthi T , Snegasri S
Published: March 2021

The APB (Advanced peripheral bus) protocol is a part of AMBA(advanced microcontroller bus architecture) family. Design under test (DUT) is tested and it establishes the communication between master (test bench) and slave (design). It is designed based on a reusable based methodology for system on chip (SOC) which is essential in order to meet the current VLSI challenges. APB involves low bandwidth, low cost and minimal power consumption and is used to connect the Timer, Keypad and other devices to the bus architecture. The work involved is of APB protocol design and implementation. Here we are designing six test cases namely single and multiple write transaction with and without wait, multiple write transaction with and without wait states, multiple read and write transaction with and without wait. The design is programmed using Verilog HDL and tested using verilog test bench. And finally the APB design is verified using QuestaSim tool.
High Speed Vlsi Architectures Of Fir Filters For Image Applications – A Review
Authors: Mary John Tintu , Chacko Shanty
Published: March 2021

Numerousapplications based on VLSI architectures suffer from large size components that lead to an error at the design stage of floating point arithmetic. Therefore, in the design of a VLSI implementation of FIR filter for various applications such as images increases the design complexity and the time delay effect of the model. This lead tohave difficultyofarchitecturethatincludes the competing requirements like speed, area, and power, application area specialization and knowledge, changing and evolving terms. In this paper, a brief review of VLSI architectures in the field of image processing is depicted such as compression, interpolation, which will be advantageous in order to tackle the issues caused by the complexity in the design and design an optimal architecture with the necessary factors that need to be satisfied.
Design of a Memory Array Using Tail Transistor and Sleep Transistor Based 7T SRAM with Low Short Circuit and Standby Power
Authors: Krishnaraj R , Soundarya B , Mythili S , Vikram N
Published: March 2021

The display hardware concentrates on planning low power control gadgets due to the utilization of versatile battery-powered gadgets. Ultra low energy process of memory clusters has ended up undying due to its uses in low voltage calculation and communications. Stable SRAM process is valuable for the success of low-power due to parameter variations in scale-down technologies. In expansion to control utilization, the SRAM’s get to time is another complex parameter due to the inevitable exchanging exercises utilized for distinctive squares, say SRAM cell, get to NMOS transistors, NMOS preload transistors, a yield sense enhancer and both decoders. It has been appeared that the tail transistor-based 6T SRAM cluster comes up short to realize solid standby control and less delay process. The proposed inactive arbitrary get to memory (SRAM) plan gives an approach towards diminishing the standby control scattering. The design uses a sleep transistor which helps in limiting the standby power by preventing the whole cell from working for unwanted operations. It is eligible for low power applications due to the supply voltage being 1.8V. The designed SRAM cell has single-ended write and reads operations, which can also reduce the total power dissipation and the tail transistor reduces the short circuit energy consumption. The design is verified with Cadence (45nm) and the power estimated as 4.6789pW, which is 78.2% of ordinary 6T SRAM block.
Implementation of efficient MAC for DSP applications using Modified Booth Encoding algorithm technique
Authors: Tamilselvan S , Dharani S , Ramesh R , HemaPriya K
Published: March 2021

Multiplier and MAC is fundamental elements in DSP processors. Multiplication is one of the essential functions of arithmetic operation in computing systems, performing with different multipliers with different algorithms. MAC consisting of multiplier, adder and accumulator which plays a vital role in various DSP applications in improving signal processing ability, FIR and IIR filters. This article concentrates particularly on the efficient implementations of an accurate, signed and unsigned point multiplier. A modified booth Encoding (MBE) multiplier is used to execute a multiplier in floating point multiplier in order to significantly reduce partial products into half. CSA is applied with the inclusion of partial products in order into half. CSA is applied with the inclusion of partial products in order to improve speed.Rounding is not introduced to make the multiplier of a MAC unit more precise. Hence the proposed system shows an improved performance in systems area by 64.77%, reduced surplus power consumption by 44.41%, delay is reduced by 80% and shows a less circuit cost efficient. This proposed system area, power, delay, area delay product and power delay product are designed and calculated using synopsis, advanced VLSI tool.
Determination of Switching Angle from Inductance Profile of Converter Fed Switched Reluctance Generator in Wind Energy Conversion System
Authors: Mohamed Arafath Rajack B , Ganesh S , Sarojini Mary S , Richard Jimreeves JS
Published: March 2021

Now a day’s Switched Reluctance Generator (SRG) had been used in renewable energy applications. The main aim is to detect the angle of switching in 1kW 8/6 SRG in Wind Energy Conversion System (WECS) for various structures of rotor and stator. The Generator is turned on by the classic converter. The switching angle is determined by analyzing the inductance profile of each structure. The generator is analyzed using Infolytica MagNet software. The Shaft is driven at a constant speed. The air gap length is 0.5mm for all structures. The material taken for analysis is cold rolled steel. The dimensions of the generator depend upon the B-H curve of the material used. With B-H curve the total ampere turns of the generator can be evaluated. SRG is excited by voltage source for starting and after some times the switch will turn off the voltage source. Once SRG turned on during decreasing profile of inductance curve, the power generated will be transferred to the load or grid.
Monitoring & Tracking System for Elephants Using GPS/GSM with Smart Electric Fencing
Authors: Rajalashmi K. , Hemachandira V.S. , Saravanan S. , Chandru M , Kaviyadevi R.S.
Published: March 2021

Increased urbanization majorly causes human wildlife conflicts. Annually 30-40 elephants were killed during crop raids in India. Several million dollars were paid as the compensation for the people. Electric fencing is used to give an impulse shock to elephants but it is an open loop system it continuously gives the electric supply there will be the wastage of the electric supply. The presence of elephants can be tracked using GSM/GPS module and the required electric fencing can be turned on/off automatically by sensing the elephants. This system also used to automatically monitor elephant and also prevent its injuries during rail crossing. It also made necessary food arrangement by tracking the elephant activities. Electrocution of elephants will be greatly reduced and elephant life and human life can be greatly protected. This system protect the elephants and human and it will be very useful to maintain the ecological balance in the world.
Matlab based simulation for overcurrent protection in induction motor drive
Authors: Santhosh kumar K.V. , Senthilkumar R.
Published: March 2021

The fault occurring in power system is a very big threat to the industries and it adversely affects the industrial drives which in turn reduce the lifetime of the drives. There are many types of faults occurring in power system which affects the current, voltage, frequency and power fed to the industrial drives. In this paper, simulink model of a three phase supply is fetched and converted to variable AC through the converter circuit and fed as an input to the commonly used industrial motor drive is designed along with overcurrent current protection system. It also visualizes the fault occurrence parameters with the help of displays on the considered industrial drive and a method to prevent the damage of drive caused due to occurrence of fault.
Predictive control for Islanded mode DG with Voltage Source Inverter
Authors: Sathiyanarayanan T , Nivesh Kumar K
Published: March 2021

This paper explains the predictive control of three phase islanded mode VSI interfaced DG. The controller aims are twofold: a)Maintain the nominal voltage and frequency, b)Supply the required load power. The inner current control loop is Predictive control- Finite Control Set Model Predictive Control (FCS-MPC), using one step ahead predicting algorithm-improving the dynamic response. The power electronic converters are made up of switches, which are discrete in nature-i.e., either ON or OFF. Conventional MPC is simplified by taking advantage of this nature and converts the actual optimisation problem into evaluate and choose the best solution type problem. Because of the limited number of switching states, the evaluation is quick and can be considered to an online optimal control.
Robust Controller And Industrıal Internet For The Industrıal Nonlınear Level Process
Authors: Arun jayakar S , Tamilselvan G.M. , Sakthiya Ram S. , Kalimuthu M.
Published: March 2021

Automatic gain scheduling of PID controller gives monstrous yield reaction for controlling tank level away industrial application. This proposed strong controller furnishes tasteful yield reaction with least pinnacle overshoot, brisk settling time. The Industrial Internet of Things (IIoT) is generally used to interconnect accessible enterprises assets and give dependable, powerful and brilliant checking and control includes in process businesses. The proposed work outlines the use of IoT in a straight tank framework, checking and change set point and controller parameters from remote spots utilizing cloud administrations. In this paper, a basic straight tank exploratory setup is created and level in the direct tank framework is controlled utilizing PID controller. Utilizing IoT and electronic administration blynk, the information can be checked and dissected from any piece of the world at whenever. Set point and PID controller parameter of the straight tank framework can likewise be adjusted.
A Novel Approach on PLCC Based Domestic Data Communication
Authors: Sridhar J , Lingeswaran G
Published: March 2021

A significant aspect of the future power grid is used for communication. The electrical power network, with its widespread network and access, is a very big network serving almost every portion of the world’s locations. Here the electrical network is utilized as a communication media. Control signals transferred over the electrical line is widely famous day by day. In this paper Power Line Carrier Communication (PLCC), is a method of handling the use of current power lines for data transfer in the home or workplace. There are properly built electricity lines in every house and building, it is utilized as a high-speed organization passageway without building another organization. Data transferred in full-duplex mode in AC cable and it is available, low cost, high reliability, and security, PLCC can be a preferred option than free-space communication technologies. Due to the above advantages, PLCC may be a preferred option over wireless communication or other technologies for home networking.
Modelling And Simulation Of Pv-Bes Based Microgrid System Operating In Standalone Mode
Authors: GAAYATHRI M. , RANJITH KUMAR K.
Published: March 2021

This work presents, a novel PV-Battery Energy Storage based microgrid system operating in standalone mode. The output of Solar PV changes with varying atmospheric condition. A boost converter is utilized as a DC-DC converter which extracts the maximum power coming out from the solar PV array, with the use of P&O algorithm. Battery Energy Storage System (BESS) is introduced to supply load uninterruptedly. In this project, lead acid battery is used. The energy management is done by the battery control mechanism. Battery and load are connected in parallel with the dc-dc boost converter. Based on the power generation in PV, battery gets charged and discharged. There are two cases considered in this project. In first case, both the load and battery is supplied with generated PV power. In second case, load is supplied with the help of both battery and the Solar PV. The proposed system is modeled and simulated in MATLAB. Parameters like battery current and voltage (Vbat,Ibat),load current and voltage (Vdc,Iout), SOC level of battery are observed and analyzed.
RETRACTED: Power Quality Issues Compensation using ANN Techniques
Authors: Veerakumar S , Selvabharathi P , Sathishkumar S
Published: March 2021

This idea is to propose an active filter which adopts to power quality issues and to solve this through Artificial intelligence techniques. This proposed active filter is combined to shunt active filter (SAF) which is controlled by neuro fuzzy interference system (ANFIS). This proposed adaptive filter performance is enhanced by ANFIS tool. This ANFIS is a class of adaptive system these functions are equivalent to fuzzy based systems. The purpose of ANFIS is to control the discharging time of dc-link capacitor in SAF there by reduces the power quality issues. The dc-link voltage values are get affected by the load fluctuation and these fluctuations can be suppressed by measuring and regulating the reference voltage. The purpose of ANFIS base adaptive shunt active filter is to achieve enhanced power quality there by reducing dc link voltage and current fluctuations very quickly. The proposed technique implemented and results are obtained using MATLAB its performance is evaluated through reference value.
Experimental Studies on the Application of Biomass Gasifier for Drying Tapioca in Remote Areas
Authors: Murugan P C , Saji Raveendran P
Published: March 2021

Drying has a significant impact in the preservation of agricultural products. The dried foods have long shelf life because the moisture content is so low and the growth spoilage organisms are reduced. Although solar drying is a popular method, many rural places do not have a suitable climate for it. So it is important to develop a dryer that works with other technologies. This articles presents the design and fabrication of biomass based dryer which can be used to dry agricultural yield in rural areas. The biomass used in the gasifier is cheap and locally available. The dryer is designed to dry Tapioca and to test the effectiveness of the dryer at regular time interval during the whole drying process. The drying was carried between the temperature limits of 60°-70°C at constant mass flow of producer gas. The final moisture content of the Tapioca was recorded as 5% to 12%. The biomass based dryer reduces the drying time by 50% when compared with open sun drying. From experimentation it is observed that the biomass based dryer is more efficient than the traditional open sun drying.
Fault identification in a grid connected solar PV system using Back propagation Neural Network
Authors: Mano Raja Paul M. , Kannan R. , Leeban Moses M. , Bhuvanesh A.
Published: March 2021

Albeit the government buoy up the penetration of renewable energy sources (RES) particularly solar photovoltaic (PV) system, the dependency on fossil fuels is still growing. The power generation using solar PV system may enhance when the enactment of solar PV system is improved. The faults occurred in the system is an important performance degradation factor. Incessant studies have been performed to identify and mitigate the faults. Currently, several smart techniques are utilized to identify the faults rapidly. In this study, Back Propagation Neural Network (BPNN) has been implemented to identify the faults. The output power get degraded when the faults happened in source side, Maximum Power Point Tracking (MPPT), DC-DC converter, rectifier and grid. The investigations has performed on 100 kW solar PV system using Matlab. The outcomes imply that the proposed method has detected the faults quickly, economically and effectively.
Corona smart watch – the reminder friend
Authors: Shanmathi sri R , Sasireka U , Shwetha M , Tamilselvan S
Published: March 2021

The present world is attacked by covid-19 which has become a pandemic situation to all the people. The spread is increasing and have been attacked up to 50-60% of the individuals, due to not protecting themselves from affected persons and not practicing social distancing. In this paper it notifies the people to protect themselves by keeping social distancing using a sensor called ultrasonic. Using thermal camera which is fixed in the watch can detect the body temperature of the neighbour person which will be able to find the infected person. The person will be notified to sanitize their hands whenever they reach their home (specific destination) using geo fencing service. This wearable device alerts the individuals to protect them from the current covid-19 which has become a global pandemic.
Voice-O-Mata Using IOT
Authors: Mohan Raj K. , Balaji N. , Jayanthi G. , Naveen P. , Vengatesan S. , Aakash A.M.
Published: March 2021

Waste bins are being used in an indoor environment by every common man for over many decades. Proper Voice-o-mata is a blend term of Voice Automation. Automation is a term which has been gaining a lot of attention lately. The idea of this project is using the HT-05 Bluetooth module and Arduino IDE achieving automation of a home or industry using IoT. Also inherent Security system composed of features like password protection of home or industry, Flame and Smoke detection and alarm system. This flexible and reliable setup which is capable of being implemented real time minimizes human effort and also increases security features. The significant feature is that over conventional automation features this setup uses voice based automation. This may be further extended to achieve full scale security, real-time monitoring of devices.
Investigations of Antifriction bearing defects using Vibration Signatures
Authors: Hariharan V. , Thangavel P. , Rajeshkumar G. , Deepa D
Published: March 2021

Antifriction bearing failure is a major factor in the failure of rotating machinery. As a fatal defect is detected, it is common to shut down the machinery as soon as possible to avoid catastrophic damages. Performing such action typically results in substantial time and economic losses. Therefore it is important to monitor the conditions of antifriction bearings and to know the details of the severity of defects before they cause serious catastrophic consequences. The vibration monitoring technique is the most suitable method to analyze various defects in bearing. This technique can provide early information about progressing malfunctions. Time-domain analysis and frequency domain analysis have been employed to identify different defects in bearing running at three different speeds. Defect-free and defective bearing are used for testing. Time-domain and frequency-domain signals acquired for both good and defective bearings Time waveform indicated the severity of vibration in defective bearings. The frequency spectrum is used to identify the amplitudes corresponding to fault frequencies and enables to predict of the defect presence. The roller bearing is considered for analysis. Three types of defects namely outer race, inner race, and rolling element defect are considered. Experimental data of both defect-free and defective bearings are processed to show the effectiveness of the fault diagnosis using this method. In fault monitoring and diagnostics of bearings, real-time processing and fast on line fault indication are becoming increasingly important. Towards this goal, attention has focused on a search for the use of effective signal processing and signatures extracting methods to realize immediate fault detection.
A Review on Bio-Composite Materials
Authors: Manikandan S , Gokulanathan L , Thangavel P , Sathishkumar S
Published: March 2021

Composite material constitute of different materials to have better characteristics than traditional materials. Material properties such as physical, chemical and mechanical properties can be tailored in composite material based on requirements. This advantage extends the composite material applications in the field of human implants. Traditional metals or ceramics have certain limitations after the implantation in human body, because of its inheriting properties with biological tissue. These limitations can be eradicated by the composite material; it makes composites to fabricate implant for biomedical applications. The new research works enhance the composite materials to mimic the natural bone, biological functions and tissue characteristics. Human tissue and bone are naturally graded from the core side, functionally graded material (FGM) implant overcome some limitations of composite materials. FGM implants elastic modulus can be tailored as like a composite material, its biological functions similar with natural one. Other biological parameters such as corrosion, wear resistance and fracture toughness are considered when designing the implant. This article discusses composite material advantage and limitations of both composite and FGM implants.
Quantifying Carbon Emission from Campus Transportation: A Case Study in Universiti Kebangsaan Malaysia
Authors: binti Zakaria Nurul Farhana Filza , Mat Yazid Muhamad Razuhanafi bin , Fadilah Yaacob Nur Fatma
Published: March 2021

Carbon footprint is a global concern discussed throughout the globe. The daily activities on university campuses cause emission of greenhouse gases that contribute to the increasing amount of carbon dioxide (CO2) in the atmosphere. This research seeks to determine the CO2 emissions by members of the campus community of Universiti Kebangsaan Malaysia (UKM), Bangi Campus. This study will also analyse the factors influencing CO2 emission from the vehicles used on the campus. The findings of this study will serve as a basis to propose methods for reducing carbon footprint, especially from the transportation used on the campus. The study is carried out on the UKM campus to gather the data on the travel activity on the campus, where the members of the campus community serve as the study population. The DEFRA Model is used to calculate the CO2 emission and the multivariable linear regression model is used to identify the factors influencing CO2 emission. In the car category, petrol cars with 2.0L engine have the highest mean CO2 emission of 1181.0932 kg CO2/year/capita. In the motorcycle category, petrol motorcycles with engine capacity larger than 500cc recorded the highest emission of 999.1072 kg CO2/year/capita. The CO2 emissions by both categories are below the national mean carbon dioxide emission value of 7900 kg CO2/year/capita recorded by the 2019 National Transport Policy and the mean carbon dioxide emissions of 5400 kg CO2/year/capita in high-income countries. In this study, the critical factors influencing the daily and annual CO2 emissions are the mode of transportation, type of fuel, and travel distance
Design of EWMA-type control chart
Authors: You H W , Shahrin M A , Mustafa Z
Published: March 2021

A control chart is typically examined based on the overall performance. This is crucial, as it will influence the final decision on the selection of a control chart. For this reason, the application of average run length (ARL) has been identified as the standard performance metric. In order to calculate ARL, practitioners must determine the size of the process shift in advance. Nevertheless, in practice, the process shift size cannot be predetermined, as practitioners may not have the requisite information associated with the process. Hence, in this work, the expected average run length (EARL) is employed as a performance metric for the unknown shift size in a process. This work evaluates the performance of a memory-type control chart, i.e. exponentially weighted moving average median (EWMA median) chart, with respect to ARL and EARL. The results indicate that, as long as the deterministic shift size is within the range of the process shift size, the chart’s performance is nearly the same, regardless of the use of the optimal pair based on minimizing ARL or EARL.
Wind turbine modelling and simulation using Matlab / SIMULINK
Authors: Chong C H , Rigit A R H , Ali I
Published: March 2021

Malaysia is aiming to reduce the dependency on oil and gas by increasing the utilization of renewable energy. One of the promising renewable energy available is wind energy. Malaysia is located near the equator which is situated in a low wind speed region with an annual mean wind speed of 1.2-4.1 m/s. However, Malaysia also experiences two different monsoon seasons which is the southwest monsoon and the northeast monsoon. Wind speed during the southwest monsoon season can reach 7 m/s while the wind speed during the northeast monsoon can exceed 15 m/s. Limited researches and studies had been done to investigate the potentiality of wind energy in Sarawak, Malaysia. In this paper, modelling and simulation of different wind energy conversion system (WESC) using different generators operating under the same parameters will be carried out using MATLAB/SIMULINK to investigate the efficiency of the generators. PMSG has shown to be more efficient over SCIG and DFIG for lower wind speed although all of them eventually reaches the similar efficiency. Efficiency of SCIG, DFIG and PMSG for rated wind speed are 66.25%, 69.38% and 71.88% respectively.
The geometric optical characteristics of Morse lens and its inside-out version
Authors: Xue Shuwen , Xiao Wen , Chen Huanyang
Published: March 2021

In this letter, we will explore the geometric optical characteristics of Morse lens. We derive the general trajectory formula and find that parts of them in generalized Eaton/Luneburg lenses are coincided to circles. Moreover, we find a new kind of combined lenses that can perform perfect images on the basis of Morse lens. Our work provides new ideas for Morse lens, other traditional lenses and their combinations.
Behaviour of nanocrystalline tricalcium silicate-based cements at early stages of hydration
Authors: Torres-Moreno América Yazmín , Belío-Reyes Irma Araceli , García-Medina Sandra , López-Camacho Perla Yolanda , Millán-Malo Beatríz , Rivera-Muñoz Eric , Bucio Lauro
Published: March 2021

Tricalcium silicate-based cements (TCS-BC) have reached great relevance in modern dentistry, where they are used in root-end filling or perforation repair treatments, and also for restoring deep and/or voluminous coronary carious lesions, among other applications. In some TCS-BC such as BiodentineTM, the physical and chemical properties, e.g. high compressive strength, have led to consider this cement as a dentine substitute. One of the drawbacks of BiodentineTM is its very high washout; which refers to the tendency of disintegrate at initial stage of hydration upon early contact with blood or other fluids, just at the moment after it is still as a freshly prepared paste. The present research was focused to compare properties related to workability and hardening at early stages of hydration of experimentally synthetized nano-sized tricalcium silicate (nTCS) and BiodentineTM (BIOD). Both pastes were tested for hardening at 0, 1, 2 and 3 h of hydration, using a penetration test adapted from standards D3441-79 and D1558-84. The hydrated products were evaluated by X-ray diffraction (XRD), thermogravimetry (TG) and 29Si NMR spectroscopy; pH measurements were taken along 28 days of hydration. The set cement pastes were evaluated for sealing ability and microleakage. Following literature reports, the CSH phase as a hydration product, was identified and modeled in both cements as defective clinotobermorite Ca11Si9O28(OH)2·8.5H2O. The CSH phases obtained differ from each other by its microstructural arrangement and packing densities, which depend on the w/c ratio of nTCS and BIOD pastes, which were 0.5 and 0.36 respectively. The hardening of BIOD is significantly influenced by its w/c ratio with a hydration fluid that presumably contains about 0.05% of polycarboxylate-based superplasticizer, which was identified by Raman spectroscopy. The washout and hardening properties were pictured by and scheme for flocculation, w/c ratio, and packing density of the CSH particles characterizing the cement pastes.
Investigation of x-ray attenuation property of modification PbO with graphene in epoxy polymer
Authors: Ghaseminejad Mahdieh , Gholamzadeh Leila , Ostovari Fatemeh
Published: March 2021

This research aims at the X-ray attenuation effect of Graphene oxide (GO) and lead (∣∣) Oxide (PbO) in epoxy resin (ER). First, GO was synthesized with Hummers’ method, then PbO modified with GO and finally, epoxy-based composites were prepared with various fillers such as GO and PbO/GO with different weight percentages. The composite samples were made in thicknesses of 2, 4, and 6mm. The composites were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and tensile strength. X-Ray attenuation mass attenuation coefficient were measured when the composites were placed at the distance of 60cm from diagnostic X-rays. The measurements were performed at 20, 40, 60 and 80 kVp. The results indicated that, among all other composites, ER-PbO-GO in 10 wt.% has the best X-Ray shielding property and GO is a suitable candidate for modified metal oxides to attenuation.
Microwave-assisted heating behavior of amorphous SiC fibers derived from polycarbosilane
Authors: Joo Young Jun , Cho Kwang Youn
Published: March 2021

In this study, polymer-derived SiC fibers fabricated using low-melting point PCS (polycarbosilane) were prepared in a mat shape for application as a microwave-assisted heating element. In addition, polymer-derived SiC blocks of various shapes were prepared under the same conditions to verify the heating behavior under the microwave. As a result, the polymer-derived SiC generated more than 1500 °C of heat in tens of seconds under the microwave. The polymer-derived SiC also exhibited different microwave-assisted heating behavior and maximum heating temperature depending on its shape. This microwave heating behavior meant that polymer-derived SiC was more dependent on the conduction loss mechanism than the dipolar loss mechanism. Therefore, as the pyrolysis temperature increased, the pi-electrons needed for the conduction loss were observed by Raman analysis and showed a tendency similar to the heat-generating behavior as the pyrolysis temperature increased.
Magnetic and structural characteristics of ambient pressure fcc phase Ho and Tb thin films
Authors: Butler T , Buckley R G , Granville S
Published: March 2021

We report the results of an investigation into the structural and magnetic properties of thin films of Ho and Tb sputtered on Ta-buffered Si substrates. As is often reported in thin films and nanoparticles of the rare earth (RE) metals, we observe both hcp and fcc phases where the relative fraction of each depends on the deposition conditions. The presence of a fcc RE phase at ambient conditions is generally claimed to be strain stabilised as in the bulk the fcc phase is only thermodynamically stable at elevated pressures. We find the lattice constants of the fcc phases in our films to coincide with values for the Ho- and Tb- hydrides, and analysis of the magnetic measurements shows that the Ho fcc phase is paramagnetic at ambient temperatures and antiferromagnetic at low temperatures, also a feature of the RE-hydrides. By considering both the structural and magnetic measurements on Ho and Tb films together, we demonstrate that the observed fcc phase is the antiferromagnetic rare earth hydride, which readily forms at the RE/Ta interface in the presence of the residual and outgassed hydrogen in vacuum chambers.
Laser fusion cutting: evaluation of gas boundary layer flow state, momentum and heat transfer
Authors: Borkmann M , Mahrle A , Beyer E , Leyens C
Published: March 2021

The present work deals with the evaluation of gas boundary layer characteristics under conditions of a high-pressurized gas flow through narrow kerfs as prevalent in laser fusion cutting. A simplistic two-dimensional channel model with appropriate boundary conditions in combination with empirical correlations of the similitude theory is applied to determine the flow state and the thickness of the boundary layer as well as magnitudes of momentum and heat transfer rates. The estimations show that the most expectable flow state of the boundary layer corresponds to a transitional regime. Calculated boundary layer thicknesses lie in a range of 100 to 300 microns after a considered running length of 10 mm. Thus, the formation of the characteristic cut edge topography with typical maximum roughness values for Rz of about 50 microns for high-quality solid-state laser fusion cuts will take place within the boundary layer region. It can be concluded, that the knowledge of the particular spatial and temporal flow structure of the boundary layer should be considered of being indispensable for a profound understanding of the formation mechanisms of the cut edge topography.
High performance mid-wave infrared photodetector based on graphene/black phosphorus heterojunction
Authors: Zhang Xuemin , Yan Changling , Hu Xin , Dong Qingsong , Liu Zhiyi , Lv Weiming , Zeng Chunhong , Su Ruigong , Wang Yiqun , Sun Tianyu , Xing Zheng , Pang Chao , Zhang Baoshun , Shi Wenhua , Long Minsheng
Published: March 2021

Black phosphorus (BP) as a promising candidate for mid-wave infrared (MWIR) detection has attracted much attention. However, the high-speed photoresponse at the MWIR is yet to be a challenge. In this paper, we report a BP-graphene heterostructure photodetector with fast photoresponse at MWIR range using molybdenum electrode as a contact to realizing a low Schottky barrier. The device exhibits a fast photoresponse in a broad-spectrum range from visible to MWIR (0.67–4.2 μm). A high photovoltaic responsivity up to 183 mA W−1 and EQE up to 35.6% were realized at the visible range of 0.637 μm light and respectively 7.9 mA W−1 and 0.31% at MWIR 3098 nm. The specific detectivity D* = 6.69 × 108 Jones is obtained at 1 mV bias under the illumination of the MWIR 4.25 μm in the ambient condition. Our work may open a new way to realizing fast MWIR photoresponse at the low light level.
Improving the corrosion resistance of LY12 aluminum alloy via a novel Mo–Zr–Ti composite conversion coating
Authors: Qian Xuzheng , Zhan Wen , Pan Jingjing , Liu Yiting , Huang Feng , Wang Beiji
Published: March 2021

To improve the corrosion resistance of LY12 aluminum alloy, a novel Mo–Zr–Ti composite conversion coating on its surface was prepared. The surface morphology, elements distribution, phase compositions and the corrosion resistance were systematically determined, and the relation between them were established. The results indicate that the optimal conversion temperature and conversion time are 40 °C and 15 min, respectively. The surface morphology of the composite coating under the best conversion condition is continuous and dense. The major elements are Mo, Zr, Ti, Al, O and F, and their distribution between the inner and outer coating are distinction. The phase compositions mainly consist of MoO3, Mo2O5, TiO2, ZrO2, Al2O3, AlF3∙3H2O, Na3AlF6 and ZrF4, and the nucleation and growth mechanisms are proposed. Additionally, the composite coating can significantly reduce the I

corr
and increase the film resistance R

f
in the temperature range from 0 to 60 °C through electrochemical test, and its activation energy E

a
increases from 25.7 to 34.5 kJ ∙ mol−1. Compared with Al matrix, the average corrosion rate of the composite coating is reduced by 65% to 85% in the full immersion test. Therefore, the composite conversion coating greatly improves the corrosion resistance of Al matrix.
From InGaN pyramids to micro-LEDs characterized by cathodoluminescence
Authors: Gustafsson Anders , BI Zhaoxia , Samuelson Lars
Published: March 2021

We present a study of the optical properties of various steps in the process of fabricating micro light-emitting diodes (μ-LEDs) based on quantum wells embedded in micron-sized InGaN platelets. In this study, we focus on structures for red emission, but the technology is equally suitable for the less technologically challenging blue and green emitting μ-LEDs. The starting point is growth of an InGaN pyramid with a sub-micron sized hexagonal base. The pyramid is flattened to create a flat top c-facet for the subsequent InGaN quantum well growth. We compare two approaches, reshaping of the pyramid by high-temperature annealing; and by chemical mechanical polishing. Their merits are discussed. The flattened platelets are used as templates to grow low-strain single quantum wells in both heterostructures and full LEDs including n- and p-barriers on either side of the quantum well. The structures are investigated in terms of homogeneity in peak energy position and intensity using hyperspectral cathodoluminescence imaging. We observe that the main contribution to inhomogeneity is the growth of the initial pyramid, that exhibits regular, facet driven variations in the In incorporation.