Md. Riyad Tanshen | Gyeongsang National University (original) (raw)

Papers by Md. Riyad Tanshen

Optics and Photonics Journal

This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fibe... more This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10 −2 at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10 4 at 1550 nm.

Middle East Journal of Applied Science & Technology

This paper describes a unique study that uses multiple FIR adaptive filter algorithms to denoise ... more This paper describes a unique study that uses multiple FIR adaptive filter algorithms to denoise adult electrocardiogram (ECG) data. The study looks at how power line interference, external electromagnetic fields, random body motions, and breathing impact ECG measurement accuracy. The article takes a fresh look at Savitzky-Golay filtering techniques by implementing and evaluating them inside the FIR adaptive filter architecture. Matlab is used to evaluate the performance of the Affine projection FIR adaptive filter (AP), Direct-form Normalized least-mean-square FIR adaptive filter (NLMS), and Sliding-window Recursive least-squares FIR adaptive filter (SWRLS). The results show how different strategies compare in terms of performance and their influence on recorded waveform quality. The study extends to our understanding of the efficiency of FIR adaptive filter algorithms in decreasing ECG signal noise and helps us better understand their potential uses in ECG signal processing. Based...

Asian Journal of Basic Science & Research

This article presents a comprehensive analysis of a 16-FSK modulator and demodulator's perfor... more This article presents a comprehensive analysis of a 16-FSK modulator and demodulator's performance over a Rician fading channel, which accurately models wireless communication channels with line-of-sight and non-line-of-sight components. The study investigates the impact of various parameters, including the Rician K-factor, Maximum Diffuse Doppler Shift, and Delay Vector, using the MATLAB Simulink communication blockset. The results indicate that increasing the K-factor and delay vector of the channel leads to an improvement in bit error rate. Additionally, it is observed that the maximum diffuse Doppler shift has minimal influence on the bit error rate. These findings provide valuable insights into optimizing the performance of 16-FSK modulation schemes in Rician fading channels, thereby enhancing the design and deployment of wireless communication systems.

International Journal of Robotics and Control Systems, 2021

This paper presents the design and execution of a solar tracker system devoted to photovoltaic (P... more This paper presents the design and execution of a solar tracker system devoted to photovoltaic (PV) conversion panels. The proposed single-axis solar tracker is shifted automatically based on the sunlight detector or tracking sensor. This system also removes incident sunlight overlapping from sensors that are inside the sunlight tracking system. The Light Dependent Resistor (LDR) is used as a sensor to sense the intensity of light accurately. The sensors are placed at a certain distance from each other in the tracker system to avoid sunlight overlapping for maximum power production. The total system is designed by using a microcontroller (PIC16F877A) as a brain to control the whole system. The solar panel converts sunlight into electricity. The PV panel is fixed with a vertical axis of the tracker. This microcontroller will compare the data and rotate a solar panel via a stepper motor in the right direction to collect maximum photon energy from sunlight. From the experimental result...

Irish Interdisciplinary Journal of Science & Research

Wireless communication is the fastest-growing segment in the communication industry, with mobile ... more Wireless communication is the fastest-growing segment in the communication industry, with mobile communication being the most widely used. However, it faces several technical challenges, such as Fading, Shadowing, Interference, and Propagation path loss. Meeting the higher demand for capacity with high-quality service is crucial. Orthogonal Frequency Division Multiplexing (OFDM) is a technique that converts wideband signals into narrowband signals for transmission, making it a suitable option for high bandwidth data transmission. The transmission of these narrowband signals is executed with an orthogonal carrier. This paper focuses on building a QAM model using MATLAB to simulate Bit Error Rate (BER) performance for real data communication under different communication channels, including AWGN and fading channels (Rayleigh and Rician). The aim is to investigate the reduction of noise and bit error rate in communication channels. The simulation model built for this research work demo...

Zenodo (CERN European Organization for Nuclear Research), Apr 5, 2023

The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely rec... more The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely recognized, and the specific absorption rate (SAR) measures the amount of energy absorbed by the human head. To meet SAR standards, mobile phones can be shielded. This paper utilizes COMSOL Multiphysics to model the human head and simulate SAR distribution for various head layers exposed to radiation from a CDMA 800 downlink frequency band mobile phone. The study also observes electric and magnetic fields across the frequency range and investigate five different shielding materials. The results reveal that a polyimide sheet outperforms other materials according to ICNIRP guidelines for electromagnetic radiation exposure. These findings have significant implications for the design and production of mobile phones, as well as public health and safety.

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science, 2022

BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It ... more BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It has a substantial impact on wireless communication channels. The significance of analyzing and comparing the performance of these two modulation techniques over the AWGN fading channel cannot be overstated. This research can be used to determine the best technique for implementing in an AWGN fading channel. To investigate the performance of BPSK and 8-FSK modulation schemes on an AWGN channel in order to calculate the error rate quantity, and to provide a solution in such cases by providing a simple programmable interface for error rate calculators and switching between different techniques using channel block-sets. The performance analysis is carried out by utilizing the MATLAB Simulink software to synthesize the design. A simulated comparative result is shown using the AWGN channel to analyze the performance of these systems. The results clearly show that the BPSK modulation technique ...

The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely rec... more The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely recognized, and the specific absorption rate (SAR) measures the amount of energy absorbed by the human head. To meet SAR standards, mobile phones can be shielded. This paper utilizes COMSOL Multiphysics to model the human head and simulate SAR distribution for various head layers exposed to radiation from a CDMA 800 downlink frequency band mobile phone. The study also observes electric and magnetic fields across the frequency range and investigate five different shielding materials. The results reveal that a polyimide sheet outperforms other materials according to ICNIRP guidelines for electromagnetic radiation exposure. These findings have significant implications for the design and production of mobile phones, as well as public health and safety.

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science, 2022

BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It ... more BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It has a substantial impact on wireless communication channels. The significance of analyzing and comparing the performance of these two modulation techniques over the AWGN fading channel cannot be overstated. This research can be used to determine the best technique for implementing in an AWGN fading channel. To investigate the performance of BPSK and 8-FSK modulation schemes on an AWGN channel in order to calculate the error rate quantity, and to provide a solution in such cases by providing a simple programmable interface for error rate calculators and switching between different techniques using channel block-sets. The performance analysis is carried out by utilizing the MATLAB Simulink software to synthesize the design. A simulated comparative result is shown using the AWGN channel to analyze the performance of these systems. The results clearly show that the BPSK modulation technique ...

Journal of the Korea Society For Power System Engineering, 2013

The article focuses on the Temperature characteristics inside single loop oscillating heat pipe (... more The article focuses on the Temperature characteristics inside single loop oscillating heat pipe (OHPs). In this paper, heat pipe is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The impact depiction has been done for the variation of tube model of the device. OHPs are made of copper capillary tubes of outer diameter 6.25 mm, inner diameter 4 mm heated by constant temperature water bath cooled by ambient temperature. Using four types of OHPs of copper capillary tubes length of 1500mm and HP length 650mm inside tubes working fluid is R-22 Pressure 8 bar and mass 34g,32g,28g,16g. The results indicate a strong influence of filling ratio on the performance

Journal of the Korea Society For Power System Engineering, 2012

：The geothermal energy is one of the renewable energy sources which can contribute in accomplishi... more ：The geothermal energy is one of the renewable energy sources which can contribute in accomplishing a vision and goal of the national plan on energy for a government suggestion. Especially, the geothermal energy is evaluated as the nearly unlimited resources. The yearly underground temperature distribution by depth is very important to the design of airconditioning system which uses a geothermal energy. Furthermore, there has no data for comparisons to numerical analysis. In this study, the yearly underground temperature is measured under the depth of 2 m in Tongyeong, and these data are compared with numerical analysis results for checking the accuracy. The results showed that the experimental temperature and numerical results had a good agreements and these results will be utilized to predict a performance of airconditioning system for using a geothermal energy.

Nanoscience and Nanotechnology Letters, 2013

ABSTRACT The article reveals heat transfer performance of multi loops Oscillating Heat Pipe (MLOH... more ABSTRACT The article reveals heat transfer performance of multi loops Oscillating Heat Pipe (MLOHP) in terms of thermal resistance and inside pressure characteristics at different angular orientation. Aqueous alumina (Al2O3) and a combination of Al2O3 with multi-walled carbon nanotubes (MWCNTs) particles in a ratio of 90:10 of weight percentages were charged individually into OHP at 60% filling ratio to investigate thermal performance. The influences of aqueous Al2O3 of 0.9 wt% as well as the Al2O3/MWCNTs of same weight concentration on thermal resistance and inside pressure distribution were investigated. The investigation of pressure characteristics inside OHP and optimization of installation angle among 0°, 30°, 60°, 90° with a variation of working fluids were significant in this study. Experimental results showed that thermal characteristics are significantly inter-related with pressure distribution and strongly depend upon the number of pressure fluctuations inside oscillating heat pipe (OHP) per unit time. A little inclusion of MWCNTs into aqueous Al2O3 facilitated the system to achieve highest number of pressure fluctuation and low thermal resistance at OHPs operational angle of 30° and 60°. Thermal resistance decreased with increasing evaporative power input at any orientation for any working fluids employed in this experiment.

International Journal of Heat and Mass Transfer, 2014

ABSTRACT The current article reports a numerical study on liquid natural gas (LNG) flow and heat ... more ABSTRACT The current article reports a numerical study on liquid natural gas (LNG) flow and heat transfer characteristic in heat exchanger at 0.6 MPa pressure condition. The computational fluid dynamics (CFD) code FLUENT was used to simulate the fluids flow and heat transfer characteristic in heat exchanger. The three-dimensional model of 1–2 heat exchangers was used to perform the numerical simulation. The numerical simulation of the current study was validated and compared with a reference data, indicating effectiveness-NTU and LMTD method. Therefore, the properties of LNG were calculated from NIST standard database 4 (SUPERTRAPP) versions 3.2. The variation effects of mass flow rate and heat transfer characteristic of the fluids were investigated. The numerical results show that the heat transfer coefficient increases with increasing the mass flow rate. Furthermore, the optimization of mass flow rate of fluids for vaporization process was reported in this study.

Energy, 2014

ABSTRACT a b s t r a c t The oscillations of liquid slugs and vapor plugs inside an oscillating h... more ABSTRACT a b s t r a c t The oscillations of liquid slugs and vapor plugs inside an oscillating heat pipe (OHP) are captured and shown in terms of pressure frequency spectrum. Pressure fluctuation inside a single loop OHP between the evaporative and the condensing sections is analyzed to evaluate thermal performance. De-Ionized (DI) water and Cu/water nanofluid with different mass fractions (0.5 wt%, 1 wt%, 2 wt% and 3 wt%) are studied subjected to the evaporative heat load of 20e120 W. Swirling, bubble creation and bubble growth phenomena are observed inside OHP integrated with circulation and oscillating motion of vapor plug and liquid slug. Furthermore, deposition of nanoparticles is found on the surface of the evaporative section of OHP when charged with nanofluid. Experimental results show that Cu/Water nanofluid containing 2 wt% of Cu nanoparticles facilitates lowest thermal resistance and highest magnitude of pressure fluctuation inside OHP. Maximum 22% efficiency is achieved by Cu/Water nanofluid with 2 wt% of Cu nanoparticles at 80 W of evaporative power input. However, thermal performance is found significantly interrelated with inside pressure fluctuation of OHP. Cu/water nanofluid is found to promote circulation and oscillation of the liquid slug and the vapor plug rather than reinforcing bubble formation and bubble growth inside OHP.

Ceramics International, 2013

This paper reports a significant enhancement in the thermal conductivity of silver-nanoparticle-b... more This paper reports a significant enhancement in the thermal conductivity of silver-nanoparticle-based aqueous nanofluids with the addition of negligible amounts of multi-walled carbon nanotubes (MWCNTs). The present work was conducted using purified MWCNTs/water nanofluids prepared by a wet grinding method. Silver nanoparticles were dispersed into the MWCNT/water nanofluids via a one-step method using pulse power evaporation, which was observed to improve the dispersibility and thermal conductivity of the nanofluids. A particle sizing system (PSS) and transmission electron microscopy (TEM) were used to confirm the size of silver nanoparticles in base fluids. The PSS measurement results reveal that the size of the silver nanoparticles was approximately 100 nm, which is in good agreement with the results obtained from TEM and SEM. The maximum absorbance (2.506 abs at a wavelength of 264 nm) and highest thermal conductivity enhancement (14.5% at 40 1C) were achieved by a fluid containing '0.05 wt% MWCNTs-3 wt% Ag' composite.

Journal of the Korea Society For Power System Engineering, 2013

：An experimental study was carried out to understand the heat transfer performance of a miniature... more ：An experimental study was carried out to understand the heat transfer performance of a miniature loop heat pipes using water-based copper nanoparticles suspensions as the working fluid. The suspensions consisted of deionized water and copper nanoparticles with an average diameter of 80 nm. Effects of the cupper mass concentration and the operation pressure on the average evaporation and condensation heat transfer coefficients, the critical heat flux and the total heat resistance of the mLHPs were investigated and discussed. The pressure frequency also depends upon the evaporator temperature which has been maintained from 60 o C to 90 o C. The Investigation shows 60% filling ratio gives the highest inside pressure magnitude of highest number pressure frequency at any of setting of evaporator temperature and 5wt% results the lowest heat flow resistance.

Journal of Central South University, 2012

ABSTRACT The pressure characteristics inside single loop oscillating heat pipe (OHP) having 4.5 m... more ABSTRACT The pressure characteristics inside single loop oscillating heat pipe (OHP) having 4.5 mm inner diameter copper tube with the loop height of 440 mm were addressed. Distilled water was used as working fluid inside the OHP with different filling ratios of 40%, 60% and 80% of total inside volume. Experimental results show that the thermal characteristics are significantly inter-related with pressure fluctuations as well as pressure frequency. And the pressure frequency also depends upon the evaporator temperature that is maintained in the range of 60–96 °C. Piezoresistive absolute pressure sensor (Model-Kistler 4045A5) was used to take data. The investigation shows that the filling ratio of 60% gives the highest inside pressure magnitude at maximum number of pressure frequency at any of set evaporator temperature and the lowest heat flow resistance is achieved at 60% filling ratio.

This paper presents the design and execution of a solar tracker system devoted to the photovoltai... more This paper presents the design and execution of a solar tracker system devoted to the photovoltaic (PV) conversion panels. The proposed single-axis solar tracker is shifted automatically based on the sunlight detector or tracking sensor. This system also removes incident sunlight overlapping from sensors that are inside the sunlight tracking system. The Light Dependent Resistor (LDR) is used as a sensor to sense the intensity of light accurately. The sensors are placed at a certain distance from each other in the tracker system for avoiding sunlight overlapping for maximum power production. The total system is designed by using a microcontroller (PIC16F877A) as a brain to control the whole system. The solar panel converts sunlight into electricity. The PV panel fixed with a vertical axis of the tracker. This microcontroller will compare the data and rotate a solar panel via a stepper motor in the right direction to collect maximum photon energy from sunlight. From the experimental r...

a Department of Electrical and Electronic Engineering, World University of Bangladesh, Dhaka 1205... more a Department of Electrical and Electronic Engineering, World University of Bangladesh, Dhaka 1205, Bangladesh b Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia c Department of Mathematics, Begum Rokeya University Rangpur, Rangpur 5400, Bangladesh d Centre for Smart Grid Energy Research (CSMER), Universiti Teknologi PETRONAS, 32610 Perak, Malaysia 1 raselbdeee@gmail.com; 2 sabsz@um.edu.my; 3 mjnahar901@brur.ac.bd; 4 moslem.uddin.bd@gmail.com; 2 mahmud220711@gmail.com; 6 riyadrt@gmail.com * Corresponding Author

This research paper deals with the design and simulation of facile and robust AC voltage originat... more This research paper deals with the design and simulation of facile and robust AC voltage originator using a solar power. PV technology is used for generating DC voltage as solar power is very reliable source. Push-pull inverter is used to convert the DC to AC as well as enhanced the magnitude of single phase signal. Matrix converter is also used to convert the single phase AC to three-phase AC signal. LCL filters are used to suppress transient and harmonic distortion of AC signals and made it pure sinusoidal output. MOSFET are used as switching circuitry for push-pull inverter. Pulse generators are affixed for triggering the MOSFET switches. Consecutive tests are performed using MATLAB SIMULINK for controlling techniques by varying irradiance and temperature of photovoltaic (PV) array. Performance analysis of Push-pull Inverter, Matrix Converter, and LCL Filter is also shown. Keywords: PV Array, Push-Pull Inverter, MOSFET Switch, LCL Filter, Matrix Converter and MATLAB SIMULINK Cite...

Optics and Photonics Journal

This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fibe... more This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10 −2 at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10 4 at 1550 nm.

Middle East Journal of Applied Science & Technology

This paper describes a unique study that uses multiple FIR adaptive filter algorithms to denoise ... more This paper describes a unique study that uses multiple FIR adaptive filter algorithms to denoise adult electrocardiogram (ECG) data. The study looks at how power line interference, external electromagnetic fields, random body motions, and breathing impact ECG measurement accuracy. The article takes a fresh look at Savitzky-Golay filtering techniques by implementing and evaluating them inside the FIR adaptive filter architecture. Matlab is used to evaluate the performance of the Affine projection FIR adaptive filter (AP), Direct-form Normalized least-mean-square FIR adaptive filter (NLMS), and Sliding-window Recursive least-squares FIR adaptive filter (SWRLS). The results show how different strategies compare in terms of performance and their influence on recorded waveform quality. The study extends to our understanding of the efficiency of FIR adaptive filter algorithms in decreasing ECG signal noise and helps us better understand their potential uses in ECG signal processing. Based...

Asian Journal of Basic Science & Research

This article presents a comprehensive analysis of a 16-FSK modulator and demodulator's perfor... more This article presents a comprehensive analysis of a 16-FSK modulator and demodulator's performance over a Rician fading channel, which accurately models wireless communication channels with line-of-sight and non-line-of-sight components. The study investigates the impact of various parameters, including the Rician K-factor, Maximum Diffuse Doppler Shift, and Delay Vector, using the MATLAB Simulink communication blockset. The results indicate that increasing the K-factor and delay vector of the channel leads to an improvement in bit error rate. Additionally, it is observed that the maximum diffuse Doppler shift has minimal influence on the bit error rate. These findings provide valuable insights into optimizing the performance of 16-FSK modulation schemes in Rician fading channels, thereby enhancing the design and deployment of wireless communication systems.

International Journal of Robotics and Control Systems, 2021

This paper presents the design and execution of a solar tracker system devoted to photovoltaic (P... more This paper presents the design and execution of a solar tracker system devoted to photovoltaic (PV) conversion panels. The proposed single-axis solar tracker is shifted automatically based on the sunlight detector or tracking sensor. This system also removes incident sunlight overlapping from sensors that are inside the sunlight tracking system. The Light Dependent Resistor (LDR) is used as a sensor to sense the intensity of light accurately. The sensors are placed at a certain distance from each other in the tracker system to avoid sunlight overlapping for maximum power production. The total system is designed by using a microcontroller (PIC16F877A) as a brain to control the whole system. The solar panel converts sunlight into electricity. The PV panel is fixed with a vertical axis of the tracker. This microcontroller will compare the data and rotate a solar panel via a stepper motor in the right direction to collect maximum photon energy from sunlight. From the experimental result...

Irish Interdisciplinary Journal of Science & Research

Wireless communication is the fastest-growing segment in the communication industry, with mobile ... more Wireless communication is the fastest-growing segment in the communication industry, with mobile communication being the most widely used. However, it faces several technical challenges, such as Fading, Shadowing, Interference, and Propagation path loss. Meeting the higher demand for capacity with high-quality service is crucial. Orthogonal Frequency Division Multiplexing (OFDM) is a technique that converts wideband signals into narrowband signals for transmission, making it a suitable option for high bandwidth data transmission. The transmission of these narrowband signals is executed with an orthogonal carrier. This paper focuses on building a QAM model using MATLAB to simulate Bit Error Rate (BER) performance for real data communication under different communication channels, including AWGN and fading channels (Rayleigh and Rician). The aim is to investigate the reduction of noise and bit error rate in communication channels. The simulation model built for this research work demo...

Zenodo (CERN European Organization for Nuclear Research), Apr 5, 2023

The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely rec... more The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely recognized, and the specific absorption rate (SAR) measures the amount of energy absorbed by the human head. To meet SAR standards, mobile phones can be shielded. This paper utilizes COMSOL Multiphysics to model the human head and simulate SAR distribution for various head layers exposed to radiation from a CDMA 800 downlink frequency band mobile phone. The study also observes electric and magnetic fields across the frequency range and investigate five different shielding materials. The results reveal that a polyimide sheet outperforms other materials according to ICNIRP guidelines for electromagnetic radiation exposure. These findings have significant implications for the design and production of mobile phones, as well as public health and safety.

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science, 2022

BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It ... more BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It has a substantial impact on wireless communication channels. The significance of analyzing and comparing the performance of these two modulation techniques over the AWGN fading channel cannot be overstated. This research can be used to determine the best technique for implementing in an AWGN fading channel. To investigate the performance of BPSK and 8-FSK modulation schemes on an AWGN channel in order to calculate the error rate quantity, and to provide a solution in such cases by providing a simple programmable interface for error rate calculators and switching between different techniques using channel block-sets. The performance analysis is carried out by utilizing the MATLAB Simulink software to synthesize the design. A simulated comparative result is shown using the AWGN channel to analyze the performance of these systems. The results clearly show that the BPSK modulation technique ...

The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely rec... more The phenomenon of radio frequency electromagnetic energy emitted from mobile phones is widely recognized, and the specific absorption rate (SAR) measures the amount of energy absorbed by the human head. To meet SAR standards, mobile phones can be shielded. This paper utilizes COMSOL Multiphysics to model the human head and simulate SAR distribution for various head layers exposed to radiation from a CDMA 800 downlink frequency band mobile phone. The study also observes electric and magnetic fields across the frequency range and investigate five different shielding materials. The results reveal that a polyimide sheet outperforms other materials according to ICNIRP guidelines for electromagnetic radiation exposure. These findings have significant implications for the design and production of mobile phones, as well as public health and safety.

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science, 2022

BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It ... more BPSK and 8-FSK modulation techniques are used in a variety of wireless communication systems. It has a substantial impact on wireless communication channels. The significance of analyzing and comparing the performance of these two modulation techniques over the AWGN fading channel cannot be overstated. This research can be used to determine the best technique for implementing in an AWGN fading channel. To investigate the performance of BPSK and 8-FSK modulation schemes on an AWGN channel in order to calculate the error rate quantity, and to provide a solution in such cases by providing a simple programmable interface for error rate calculators and switching between different techniques using channel block-sets. The performance analysis is carried out by utilizing the MATLAB Simulink software to synthesize the design. A simulated comparative result is shown using the AWGN channel to analyze the performance of these systems. The results clearly show that the BPSK modulation technique ...

Journal of the Korea Society For Power System Engineering, 2013

The article focuses on the Temperature characteristics inside single loop oscillating heat pipe (... more The article focuses on the Temperature characteristics inside single loop oscillating heat pipe (OHPs). In this paper, heat pipe is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The impact depiction has been done for the variation of tube model of the device. OHPs are made of copper capillary tubes of outer diameter 6.25 mm, inner diameter 4 mm heated by constant temperature water bath cooled by ambient temperature. Using four types of OHPs of copper capillary tubes length of 1500mm and HP length 650mm inside tubes working fluid is R-22 Pressure 8 bar and mass 34g,32g,28g,16g. The results indicate a strong influence of filling ratio on the performance

Journal of the Korea Society For Power System Engineering, 2012

：The geothermal energy is one of the renewable energy sources which can contribute in accomplishi... more ：The geothermal energy is one of the renewable energy sources which can contribute in accomplishing a vision and goal of the national plan on energy for a government suggestion. Especially, the geothermal energy is evaluated as the nearly unlimited resources. The yearly underground temperature distribution by depth is very important to the design of airconditioning system which uses a geothermal energy. Furthermore, there has no data for comparisons to numerical analysis. In this study, the yearly underground temperature is measured under the depth of 2 m in Tongyeong, and these data are compared with numerical analysis results for checking the accuracy. The results showed that the experimental temperature and numerical results had a good agreements and these results will be utilized to predict a performance of airconditioning system for using a geothermal energy.

Nanoscience and Nanotechnology Letters, 2013

ABSTRACT The article reveals heat transfer performance of multi loops Oscillating Heat Pipe (MLOH... more ABSTRACT The article reveals heat transfer performance of multi loops Oscillating Heat Pipe (MLOHP) in terms of thermal resistance and inside pressure characteristics at different angular orientation. Aqueous alumina (Al2O3) and a combination of Al2O3 with multi-walled carbon nanotubes (MWCNTs) particles in a ratio of 90:10 of weight percentages were charged individually into OHP at 60% filling ratio to investigate thermal performance. The influences of aqueous Al2O3 of 0.9 wt% as well as the Al2O3/MWCNTs of same weight concentration on thermal resistance and inside pressure distribution were investigated. The investigation of pressure characteristics inside OHP and optimization of installation angle among 0°, 30°, 60°, 90° with a variation of working fluids were significant in this study. Experimental results showed that thermal characteristics are significantly inter-related with pressure distribution and strongly depend upon the number of pressure fluctuations inside oscillating heat pipe (OHP) per unit time. A little inclusion of MWCNTs into aqueous Al2O3 facilitated the system to achieve highest number of pressure fluctuation and low thermal resistance at OHPs operational angle of 30° and 60°. Thermal resistance decreased with increasing evaporative power input at any orientation for any working fluids employed in this experiment.

International Journal of Heat and Mass Transfer, 2014

ABSTRACT The current article reports a numerical study on liquid natural gas (LNG) flow and heat ... more ABSTRACT The current article reports a numerical study on liquid natural gas (LNG) flow and heat transfer characteristic in heat exchanger at 0.6 MPa pressure condition. The computational fluid dynamics (CFD) code FLUENT was used to simulate the fluids flow and heat transfer characteristic in heat exchanger. The three-dimensional model of 1–2 heat exchangers was used to perform the numerical simulation. The numerical simulation of the current study was validated and compared with a reference data, indicating effectiveness-NTU and LMTD method. Therefore, the properties of LNG were calculated from NIST standard database 4 (SUPERTRAPP) versions 3.2. The variation effects of mass flow rate and heat transfer characteristic of the fluids were investigated. The numerical results show that the heat transfer coefficient increases with increasing the mass flow rate. Furthermore, the optimization of mass flow rate of fluids for vaporization process was reported in this study.

Energy, 2014

ABSTRACT a b s t r a c t The oscillations of liquid slugs and vapor plugs inside an oscillating h... more ABSTRACT a b s t r a c t The oscillations of liquid slugs and vapor plugs inside an oscillating heat pipe (OHP) are captured and shown in terms of pressure frequency spectrum. Pressure fluctuation inside a single loop OHP between the evaporative and the condensing sections is analyzed to evaluate thermal performance. De-Ionized (DI) water and Cu/water nanofluid with different mass fractions (0.5 wt%, 1 wt%, 2 wt% and 3 wt%) are studied subjected to the evaporative heat load of 20e120 W. Swirling, bubble creation and bubble growth phenomena are observed inside OHP integrated with circulation and oscillating motion of vapor plug and liquid slug. Furthermore, deposition of nanoparticles is found on the surface of the evaporative section of OHP when charged with nanofluid. Experimental results show that Cu/Water nanofluid containing 2 wt% of Cu nanoparticles facilitates lowest thermal resistance and highest magnitude of pressure fluctuation inside OHP. Maximum 22% efficiency is achieved by Cu/Water nanofluid with 2 wt% of Cu nanoparticles at 80 W of evaporative power input. However, thermal performance is found significantly interrelated with inside pressure fluctuation of OHP. Cu/water nanofluid is found to promote circulation and oscillation of the liquid slug and the vapor plug rather than reinforcing bubble formation and bubble growth inside OHP.

Ceramics International, 2013

This paper reports a significant enhancement in the thermal conductivity of silver-nanoparticle-b... more This paper reports a significant enhancement in the thermal conductivity of silver-nanoparticle-based aqueous nanofluids with the addition of negligible amounts of multi-walled carbon nanotubes (MWCNTs). The present work was conducted using purified MWCNTs/water nanofluids prepared by a wet grinding method. Silver nanoparticles were dispersed into the MWCNT/water nanofluids via a one-step method using pulse power evaporation, which was observed to improve the dispersibility and thermal conductivity of the nanofluids. A particle sizing system (PSS) and transmission electron microscopy (TEM) were used to confirm the size of silver nanoparticles in base fluids. The PSS measurement results reveal that the size of the silver nanoparticles was approximately 100 nm, which is in good agreement with the results obtained from TEM and SEM. The maximum absorbance (2.506 abs at a wavelength of 264 nm) and highest thermal conductivity enhancement (14.5% at 40 1C) were achieved by a fluid containing '0.05 wt% MWCNTs-3 wt% Ag' composite.

Journal of the Korea Society For Power System Engineering, 2013

：An experimental study was carried out to understand the heat transfer performance of a miniature... more ：An experimental study was carried out to understand the heat transfer performance of a miniature loop heat pipes using water-based copper nanoparticles suspensions as the working fluid. The suspensions consisted of deionized water and copper nanoparticles with an average diameter of 80 nm. Effects of the cupper mass concentration and the operation pressure on the average evaporation and condensation heat transfer coefficients, the critical heat flux and the total heat resistance of the mLHPs were investigated and discussed. The pressure frequency also depends upon the evaporator temperature which has been maintained from 60 o C to 90 o C. The Investigation shows 60% filling ratio gives the highest inside pressure magnitude of highest number pressure frequency at any of setting of evaporator temperature and 5wt% results the lowest heat flow resistance.

Journal of Central South University, 2012

ABSTRACT The pressure characteristics inside single loop oscillating heat pipe (OHP) having 4.5 m... more ABSTRACT The pressure characteristics inside single loop oscillating heat pipe (OHP) having 4.5 mm inner diameter copper tube with the loop height of 440 mm were addressed. Distilled water was used as working fluid inside the OHP with different filling ratios of 40%, 60% and 80% of total inside volume. Experimental results show that the thermal characteristics are significantly inter-related with pressure fluctuations as well as pressure frequency. And the pressure frequency also depends upon the evaporator temperature that is maintained in the range of 60–96 °C. Piezoresistive absolute pressure sensor (Model-Kistler 4045A5) was used to take data. The investigation shows that the filling ratio of 60% gives the highest inside pressure magnitude at maximum number of pressure frequency at any of set evaporator temperature and the lowest heat flow resistance is achieved at 60% filling ratio.

This paper presents the design and execution of a solar tracker system devoted to the photovoltai... more This paper presents the design and execution of a solar tracker system devoted to the photovoltaic (PV) conversion panels. The proposed single-axis solar tracker is shifted automatically based on the sunlight detector or tracking sensor. This system also removes incident sunlight overlapping from sensors that are inside the sunlight tracking system. The Light Dependent Resistor (LDR) is used as a sensor to sense the intensity of light accurately. The sensors are placed at a certain distance from each other in the tracker system for avoiding sunlight overlapping for maximum power production. The total system is designed by using a microcontroller (PIC16F877A) as a brain to control the whole system. The solar panel converts sunlight into electricity. The PV panel fixed with a vertical axis of the tracker. This microcontroller will compare the data and rotate a solar panel via a stepper motor in the right direction to collect maximum photon energy from sunlight. From the experimental r...

a Department of Electrical and Electronic Engineering, World University of Bangladesh, Dhaka 1205... more a Department of Electrical and Electronic Engineering, World University of Bangladesh, Dhaka 1205, Bangladesh b Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia c Department of Mathematics, Begum Rokeya University Rangpur, Rangpur 5400, Bangladesh d Centre for Smart Grid Energy Research (CSMER), Universiti Teknologi PETRONAS, 32610 Perak, Malaysia 1 raselbdeee@gmail.com; 2 sabsz@um.edu.my; 3 mjnahar901@brur.ac.bd; 4 moslem.uddin.bd@gmail.com; 2 mahmud220711@gmail.com; 6 riyadrt@gmail.com * Corresponding Author

This research paper deals with the design and simulation of facile and robust AC voltage originat... more This research paper deals with the design and simulation of facile and robust AC voltage originator using a solar power. PV technology is used for generating DC voltage as solar power is very reliable source. Push-pull inverter is used to convert the DC to AC as well as enhanced the magnitude of single phase signal. Matrix converter is also used to convert the single phase AC to three-phase AC signal. LCL filters are used to suppress transient and harmonic distortion of AC signals and made it pure sinusoidal output. MOSFET are used as switching circuitry for push-pull inverter. Pulse generators are affixed for triggering the MOSFET switches. Consecutive tests are performed using MATLAB SIMULINK for controlling techniques by varying irradiance and temperature of photovoltaic (PV) array. Performance analysis of Push-pull Inverter, Matrix Converter, and LCL Filter is also shown. Keywords: PV Array, Push-Pull Inverter, MOSFET Switch, LCL Filter, Matrix Converter and MATLAB SIMULINK Cite...