Underwater Optical Wireless Communication (UWOC) becomes an emerging underwater communication tec... more Underwater Optical Wireless Communication (UWOC) becomes an emerging underwater communication technology, with high-data rates over relatively medium transmission ranges. When optical wireless signal transmitted in ocean water channel, it will suffer from drastic scattering and absorption due to water molecules, dissolved particles, air bubbles, and turbulence. Absorption and scattering of the transmitted wireless optical signal in underwater channel led to attenuation in optical signal power. Optical signal attenuation over underwater channel is an aggregate of` different parameters effects that changed frequently, then practical measuring of this attenuation is complicated, difficult, expensive, and time-consuming process. In this work, improved neural network optimized with future search algorithm (FANN) was proposed, as an efficacious solution to obtain an accurate, relabel values of attenuation coefficient in different water types and conditions. The proposed FANN model provide...
Since its first implementation in the mid-eighties of the past century, Functionally Graded Mater... more Since its first implementation in the mid-eighties of the past century, Functionally Graded Materials (FGM) have been under heavy research in many directions including manufacturing techniques, modeling, and exploring possible applications. Numerous FGM models and analysis methods are continuously appended to the literature. Just like in the rest of the mechanical design field, the Finite Element Method (FEM) has been extensively used in the analysis of FGM, in addition to being a main validation tool for the other proposed methods. ANSYS has been one of the main general-purpose FEM packages that facilitate the use of FEM. However, no single publication is found exploring the modeling of FGM in ANSYS. This work does just that. It explores and compares the various techniques of modeling FGM in ANSYS using Mechanical APDL. The techniques explored here should be applicable in any other FEM package. APDL codes are provided for the various considered cases. Three main techniques of model...
World Congress on Mechanical, Chemical, and Material Engineering
Assessment of the exergetical and energical performance of a single-stage NH3-NaSCN absorption re... more Assessment of the exergetical and energical performance of a single-stage NH3-NaSCN absorption refrigeration system has carried out for the effective recovery of low-temperature waste heat of the drainage tanks in AL-Zara thermal power plant in Hama, Syria. Thermodynamic analysis, both first and second law, has employed to be a tool for consideration of the quantity and quality of energy in the thermal system. Exergy analysis has determined the destruction and losses of exergy in various components and hence in the overall system. The thermal properties, entropy, and exergy of the working mixture have also calculated to analyze irreversible loss in system components under operating conditions by MATLAB® computer program. The obtained numerical results for the cycle have tabulated where the coefficient of performance and the coefficient of performance for heating have reached up to 0.55, 1.55 respectively. The efficiencies of the second law of thermodynamics for cooling and heating applications have reached up to 0.295, 1.295 respectively.
The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmon... more The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmonary disease (COPD) have been attributed to peripheral characteristics (e.g., muscle atrophy). However, cognitive impairment may compromise motor control including walking automaticity. The objective of this study was to investigate PFC neural activity, evaluated using changes in oxygenated hemoglobin (ΔO2Hb), during preferred paced walking (PPW) in COPD patients and age-matched controls. The ΔO2Hb from the left and right dorsolateral PFC was measured using functional near-infrared spectroscopy. Fifteen COPD patients (age: 71 ± 8) and twenty age-matched controls (69 ± 7 years) participated. Two-way mixed ANOVA demonstrated that O2Hb in both groups decreased during PPW from the start (quintile 1; Q1) to the end (quintile 5; Q5) in the left dorsolateral and medial PFC. Q1 was comprised of the data during the first 20% of the task, while Q5 included data collected in the last 20% of the task...
Background: Hepatitis c virus (HCV) is a serious worldwide problem which has a great impact on he... more Background: Hepatitis c virus (HCV) is a serious worldwide problem which has a great impact on health status in the field of liver diseases with an estimation of 170 million people infected worldwide. HCV infection is gaining increasing attention as a global health problem, with approximately 3% of the world's population infected. Egypt reports the highest prevalence of HCV worldwide, ranging from 6% to more than 40% with an average of 13.8%. Today, many direct-acting antivirals (DAAs) are available with encouraging results in terms of both virologic response and safety. Objectives: The aim of this study was to evaluate the prevalence of SVR (12-24 weeks) in Egyptian patients with different Child-Pough classification, the complications and its frequency during, and after treatment with combination of antiviral agents.
PURPOSE To contrast older and younger adults' prefrontal cortex (PFC) neural activity (throug... more PURPOSE To contrast older and younger adults' prefrontal cortex (PFC) neural activity (through changes in oxygenated hemoglobin) during single and dual tasks, and to compare decrements in task performance. METHODS Changes in oxygenated hemoglobin of dorsolateral PFC were monitored using functional near-infrared spectroscopy during single tasks of spelling backwards (cognitive task) and 30 m preferred paced walk; and a dual task combining both. Gait velocity was measured by a pressure sensitive mat. RESULTS Twenty sex-matched younger (27.6 ± 3.5 years) and 17 older adults (71.2 ± 4.9 years) were recruited. The left PFC oxygenated hemoglobin decreased from start (1st quintile) to the end (5th quintile) of the walking task in younger adults ( - 0.03 ± 0.03 to - 0.72 ± 0.20 µM; p < .05) unlike the non-significant change in older adults (0.03 ± 0.06 to - 0.41 ± 0.32 µM, p > .05). Overall, oxygenation increased bilaterally during dual versus single walk task in older adults (Left PFC: 0.22 ± 0.16 vs. - 0.23 ± 0.21 µM, respectively; Right PFC: 0.17 ± 0.18 vs. - 0.33 ± 0.22 µM, respectively), but only in right PFC in younger adults ( - 0.02 ± 0.15 vs. - 0.47 ± 0.13 µM). Older adults exhibited lower velocity during the dual task compared to younger adults (1.03 ± 0.16 vs. 1.20 ± 0.17 m/s, respectively). Older age was associated with dual task cost on velocity during walking after adjusting for confounding variables. CONCLUSIONS Age-related cognitive decline in older adults may increase neural activity for cognitive tasks and diminish walking automaticity that may lead to decrements during dual tasking; the greater PFC increases in the oxygenated hemoglobin and lower velocity may be due to increased cognitive load and limited attentional resources.
The correct derivation of the buckling equations of the shear-deformable FGM plates for the exten... more The correct derivation of the buckling equations of the shear-deformable FGM plates for the extended Kantorovich method
Undoubtedly The environmental problems are all connected we cannot ignore the environmental retur... more Undoubtedly The environmental problems are all connected we cannot ignore the environmental return of the wrong use of energy and building materials and their negative impact on environment construction sector contributes significantly to the rate of global energy consumption and residues construction leads to emissions of dioxide gas Carbon. Moreover, it was urgent need to find a technology more compatible with the environment which was the beginning of using eco-friendly materials returning to nature which is not new it has started to appeal by the Architect "Hassan fathy" who started environmentally compliant architecture. Currently, the idea of alternative architecture addressed in the research is like alternative medicine where return to the original. Alternative medicine has begun to approach the use of natural methods and the dimension of chemical substances and their long-term and short-term impact. the interest of the world at present in the preservation and sustainability of the environment which is adopted by alternative architecture thinking through an alternative way of thinking to save energy with almost non-existent impact with natural base by reunion architecture with the mother of nature to rationalize energy consumption in architectural design.
Background: Nerve conduction studies (NCSs) are an invaluable aid to investigate and quantify the... more Background: Nerve conduction studies (NCSs) are an invaluable aid to investigate and quantify the physiological activity of peripheral nerves. They include measurement of sensory and motor conduction velocities and latencies of peripheral nerves which might be influenced by anthropometric factors like age, sex, height, weight, temperature and (body mass index) BMI. Objective: As mentioned in the companion paper, normative NCS parameters were lacking in Sudan, hence the aim of this study is to establish our own EMG normal neurophysiological values among adult Sudanese people. Method: A descriptive, analytic, cross sectional study investigating 200 Peroneal nerves of 100 healthy Sudanese people was conducted in Elmagzoub Neuroscience Center; supported by the Faculty of Medicine, National Ribat University, Khartoum, Sudan. Results: The normative neurophysiologic values of the Left and Right peroneal nerve CMAP (compound muscle action potential) in the whole sample of this work were sho...
This work investigates the relations between the critical temperature of the thin FGM plates unde... more This work investigates the relations between the critical temperature of the thin FGM plates under various temperature distributions through the thickness resting on the Pasternak elastic foundation. Both rectangular and skew plates are investigated. The uniform, linear, and nonlinear temperature distributions through the plate’s thickness are considered. Formulations are derived based on the classical plate theory (CPT) considering the von Karman geometrical nonlinearity taking the physical neutral plane as the reference plane. The partial differential formulation is separated into two sets of ordinary differential equations using the extended Kantorovich method (EKM). The stability equations and boundary conditions terms are derived according to Trefftz criteria using the variational calculus expressed in an oblique coordinate system. Novel multi-scale plots are presented to show the linear relations between the critical temperatures under various temperature distributions. The cr...
Experimental values of viscosity are presented for the mixtures of 7-[2,2-(1-phenylidene amino)-1... more Experimental values of viscosity are presented for the mixtures of 7-[2,2-(1-phenylidene amino)-1,3,4 – (Thiadiazole5-yl)thio acetamido]Desacetoxy cephalosporanic Acid [PATDCA] with water over the whole mole fraction range at 298.15 , 308.15 , 318.15 and 328.15 K.The data were used to calculate excess viscosity , ∆ln η and excess Gibbs energy of activation of flow ,∆G *E .Both ∆ln η and ∆G *E show a significant positive deviation from ideal mixing behavior over the whole mole fraction range and decreased with increasing temperature . The results have been discussed in terms of the nature of solvent – solute interaction in the mixture. Introduction: Knowledge of mixing properties of binary mixtures has relevance in theoretical and applied areas of research such results are needed for design processes in chemical and petrochemical industries . Some drugs such as morpholine finds application as an extractant agent for aromatic hydrocarbons from petroleum cuts [1-3]. Therefore an unders...
This work reports a modelling method of functionally graded materials (FGM) using ANSYS APDL. ANS... more This work reports a modelling method of functionally graded materials (FGM) using ANSYS APDL. ANSYS, as many other analysis software packages, does not provide a direct way to model variation in material properties as a function of position. However, ANSYS offers the option of temperature dependent properties; and ANSYS also offers the ability of assigning temperature values according to the position; joining these two abilities offered by ANSYS, the material properties would be position dependent. In this work, using ANSYS APDL, dummy thermal loads are used to obtain FGM distributed properties. The presented modelling method is explained and then applied to some case study of static analysis to verify its accuracy by comparing its results with the analytical solution from the case study source. The main advantage of such a method is its simplicity and ease; it does not require deep knowledge of mathematical models of FGM and delivers high accuracy. Although in this study ANSYS APDL...
International Journal of Design & Nature and Ecodynamics, 2021
In this paper, texts were experimentally transmitted by pulse width modulation (PWM) using an und... more In this paper, texts were experimentally transmitted by pulse width modulation (PWM) using an underwater wireless optical communication system (UWOC) in a channel containing water of varying salinity as a result of changes in the concentration of sodium chloride (NaCl). Mathematical equations are used using a MATLAB program to compare theoretical and practical results at different slop angle (θ0). (NaCl) concentration was changed from (0% w/v) to (90% w/v) to achieve different salinity of water (i.e., from clear water to turbid water). A diode laser with a power of 30 mW and a wavelength of 532 nm has been employed in the transmitter. The experimental results show that the extinction coefficient or the overall attenuation C(λ) is equal to (0.083/m) in the water containing a low concentration of (NaCl) which is consistent with pure seawater. Additionally, the obtained optical power (PR) and the signal to noise ratio (S/N) decreases to (27.6) mW and (23.99) dB, respectively. Furthermor...
The extended Kantorovich method (EKM) is implemented to numerically solve the elastic buckling pr... more The extended Kantorovich method (EKM) is implemented to numerically solve the elastic buckling problem of thin skew (parallelogram) isotropic plate under in-plane loading resting on the Pasternak elastic foundation. EKM has never been applied to this problem before. Investigation of the EKM accuracy and convergence is conducted. Formulations are based on classical plate theory (CPT). Stability equations and boundary conditions terms are derived from the principle of the minimum total potential energy using the variational calculus expressed in an oblique coordinate system. The resulting two sets of ordinary differential equations are solved numerically using the Chebfun package in MATLAB software. In-plane compression and shear loads are considered along with various boundary conditions and aspect ratios. Results are compared to the analytical and numerical solutions found in the literature, and to the finite element solutions obtained using ANSYS software. The effects of the skew angle, stiffness of elastic foundation, and aspect ratio on the buckling load are also investigated. For plates with zero skew angle, i.e. rectangular plates, with various boundary conditions and aspect ratios under uniaxial and biaxial loading resting on elastic foundation, the single-term EKM is found accurate. However, more terms are needed as the skew angle gets bigger. The multi-term EKM is found accurate in the analysis of rectangular and skew plates with various boundary conditions and aspect ratios under uniaxial, biaxial, and shear loading resting on elastic foundation. Using EKM in buckling analysis of thin skew plates is found simple, accurate, and rapid to converge.
Engineering Science and Technology, an International Journal, 2020
Multi-term extended Kantorovich method (MTEKM) is used to solve the bending problem of thin skew ... more Multi-term extended Kantorovich method (MTEKM) is used to solve the bending problem of thin skew (parallelogram) functionally graded plate resting on the Winkler elastic foundation under uniformly distributed transverse load. Formulations are based on the classical plate theory (CPT) with the physical neutral surface is considered as the reference plane. Various configurations of clamped, simply supported and free edges are considered. By implementing the concept of Galerkin's weighted residual method, the fourth-order partial differential governing equation and boundary conditions are converted into two sets of ordinary differential equations (ODE), which are then solved numerically using ''Chebfun" numerical computation package. Convergence and accuracy of MTEKM are investigated. Results obtained with MTEKM are compared to finite element method (FEM) solutions. FEM has been implemented using ANSYS software, in which the plate is modeled with shell elements, while the elastic foundation is modeled as a pair of contact/target elements. In addition, the effects of both the Winkler foundation stiffness and material power index have been investigated. Applying MTEKM in bending analysis of thin skew plates offered more accurate results than the single-term EKM but with the cost of more computation time but still provides simplicity and rapid convergence. It is found that MTEKM well suits the bending problem of skew FGM plates resting on elastic foundation.
Underwater Optical Wireless Communication (UWOC) becomes an emerging underwater communication tec... more Underwater Optical Wireless Communication (UWOC) becomes an emerging underwater communication technology, with high-data rates over relatively medium transmission ranges. When optical wireless signal transmitted in ocean water channel, it will suffer from drastic scattering and absorption due to water molecules, dissolved particles, air bubbles, and turbulence. Absorption and scattering of the transmitted wireless optical signal in underwater channel led to attenuation in optical signal power. Optical signal attenuation over underwater channel is an aggregate of` different parameters effects that changed frequently, then practical measuring of this attenuation is complicated, difficult, expensive, and time-consuming process. In this work, improved neural network optimized with future search algorithm (FANN) was proposed, as an efficacious solution to obtain an accurate, relabel values of attenuation coefficient in different water types and conditions. The proposed FANN model provide...
Since its first implementation in the mid-eighties of the past century, Functionally Graded Mater... more Since its first implementation in the mid-eighties of the past century, Functionally Graded Materials (FGM) have been under heavy research in many directions including manufacturing techniques, modeling, and exploring possible applications. Numerous FGM models and analysis methods are continuously appended to the literature. Just like in the rest of the mechanical design field, the Finite Element Method (FEM) has been extensively used in the analysis of FGM, in addition to being a main validation tool for the other proposed methods. ANSYS has been one of the main general-purpose FEM packages that facilitate the use of FEM. However, no single publication is found exploring the modeling of FGM in ANSYS. This work does just that. It explores and compares the various techniques of modeling FGM in ANSYS using Mechanical APDL. The techniques explored here should be applicable in any other FEM package. APDL codes are provided for the various considered cases. Three main techniques of model...
World Congress on Mechanical, Chemical, and Material Engineering
Assessment of the exergetical and energical performance of a single-stage NH3-NaSCN absorption re... more Assessment of the exergetical and energical performance of a single-stage NH3-NaSCN absorption refrigeration system has carried out for the effective recovery of low-temperature waste heat of the drainage tanks in AL-Zara thermal power plant in Hama, Syria. Thermodynamic analysis, both first and second law, has employed to be a tool for consideration of the quantity and quality of energy in the thermal system. Exergy analysis has determined the destruction and losses of exergy in various components and hence in the overall system. The thermal properties, entropy, and exergy of the working mixture have also calculated to analyze irreversible loss in system components under operating conditions by MATLAB® computer program. The obtained numerical results for the cycle have tabulated where the coefficient of performance and the coefficient of performance for heating have reached up to 0.55, 1.55 respectively. The efficiencies of the second law of thermodynamics for cooling and heating applications have reached up to 0.295, 1.295 respectively.
The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmon... more The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmonary disease (COPD) have been attributed to peripheral characteristics (e.g., muscle atrophy). However, cognitive impairment may compromise motor control including walking automaticity. The objective of this study was to investigate PFC neural activity, evaluated using changes in oxygenated hemoglobin (ΔO2Hb), during preferred paced walking (PPW) in COPD patients and age-matched controls. The ΔO2Hb from the left and right dorsolateral PFC was measured using functional near-infrared spectroscopy. Fifteen COPD patients (age: 71 ± 8) and twenty age-matched controls (69 ± 7 years) participated. Two-way mixed ANOVA demonstrated that O2Hb in both groups decreased during PPW from the start (quintile 1; Q1) to the end (quintile 5; Q5) in the left dorsolateral and medial PFC. Q1 was comprised of the data during the first 20% of the task, while Q5 included data collected in the last 20% of the task...
Background: Hepatitis c virus (HCV) is a serious worldwide problem which has a great impact on he... more Background: Hepatitis c virus (HCV) is a serious worldwide problem which has a great impact on health status in the field of liver diseases with an estimation of 170 million people infected worldwide. HCV infection is gaining increasing attention as a global health problem, with approximately 3% of the world's population infected. Egypt reports the highest prevalence of HCV worldwide, ranging from 6% to more than 40% with an average of 13.8%. Today, many direct-acting antivirals (DAAs) are available with encouraging results in terms of both virologic response and safety. Objectives: The aim of this study was to evaluate the prevalence of SVR (12-24 weeks) in Egyptian patients with different Child-Pough classification, the complications and its frequency during, and after treatment with combination of antiviral agents.
PURPOSE To contrast older and younger adults' prefrontal cortex (PFC) neural activity (throug... more PURPOSE To contrast older and younger adults' prefrontal cortex (PFC) neural activity (through changes in oxygenated hemoglobin) during single and dual tasks, and to compare decrements in task performance. METHODS Changes in oxygenated hemoglobin of dorsolateral PFC were monitored using functional near-infrared spectroscopy during single tasks of spelling backwards (cognitive task) and 30 m preferred paced walk; and a dual task combining both. Gait velocity was measured by a pressure sensitive mat. RESULTS Twenty sex-matched younger (27.6 ± 3.5 years) and 17 older adults (71.2 ± 4.9 years) were recruited. The left PFC oxygenated hemoglobin decreased from start (1st quintile) to the end (5th quintile) of the walking task in younger adults ( - 0.03 ± 0.03 to - 0.72 ± 0.20 µM; p < .05) unlike the non-significant change in older adults (0.03 ± 0.06 to - 0.41 ± 0.32 µM, p > .05). Overall, oxygenation increased bilaterally during dual versus single walk task in older adults (Left PFC: 0.22 ± 0.16 vs. - 0.23 ± 0.21 µM, respectively; Right PFC: 0.17 ± 0.18 vs. - 0.33 ± 0.22 µM, respectively), but only in right PFC in younger adults ( - 0.02 ± 0.15 vs. - 0.47 ± 0.13 µM). Older adults exhibited lower velocity during the dual task compared to younger adults (1.03 ± 0.16 vs. 1.20 ± 0.17 m/s, respectively). Older age was associated with dual task cost on velocity during walking after adjusting for confounding variables. CONCLUSIONS Age-related cognitive decline in older adults may increase neural activity for cognitive tasks and diminish walking automaticity that may lead to decrements during dual tasking; the greater PFC increases in the oxygenated hemoglobin and lower velocity may be due to increased cognitive load and limited attentional resources.
The correct derivation of the buckling equations of the shear-deformable FGM plates for the exten... more The correct derivation of the buckling equations of the shear-deformable FGM plates for the extended Kantorovich method
Undoubtedly The environmental problems are all connected we cannot ignore the environmental retur... more Undoubtedly The environmental problems are all connected we cannot ignore the environmental return of the wrong use of energy and building materials and their negative impact on environment construction sector contributes significantly to the rate of global energy consumption and residues construction leads to emissions of dioxide gas Carbon. Moreover, it was urgent need to find a technology more compatible with the environment which was the beginning of using eco-friendly materials returning to nature which is not new it has started to appeal by the Architect "Hassan fathy" who started environmentally compliant architecture. Currently, the idea of alternative architecture addressed in the research is like alternative medicine where return to the original. Alternative medicine has begun to approach the use of natural methods and the dimension of chemical substances and their long-term and short-term impact. the interest of the world at present in the preservation and sustainability of the environment which is adopted by alternative architecture thinking through an alternative way of thinking to save energy with almost non-existent impact with natural base by reunion architecture with the mother of nature to rationalize energy consumption in architectural design.
Background: Nerve conduction studies (NCSs) are an invaluable aid to investigate and quantify the... more Background: Nerve conduction studies (NCSs) are an invaluable aid to investigate and quantify the physiological activity of peripheral nerves. They include measurement of sensory and motor conduction velocities and latencies of peripheral nerves which might be influenced by anthropometric factors like age, sex, height, weight, temperature and (body mass index) BMI. Objective: As mentioned in the companion paper, normative NCS parameters were lacking in Sudan, hence the aim of this study is to establish our own EMG normal neurophysiological values among adult Sudanese people. Method: A descriptive, analytic, cross sectional study investigating 200 Peroneal nerves of 100 healthy Sudanese people was conducted in Elmagzoub Neuroscience Center; supported by the Faculty of Medicine, National Ribat University, Khartoum, Sudan. Results: The normative neurophysiologic values of the Left and Right peroneal nerve CMAP (compound muscle action potential) in the whole sample of this work were sho...
This work investigates the relations between the critical temperature of the thin FGM plates unde... more This work investigates the relations between the critical temperature of the thin FGM plates under various temperature distributions through the thickness resting on the Pasternak elastic foundation. Both rectangular and skew plates are investigated. The uniform, linear, and nonlinear temperature distributions through the plate’s thickness are considered. Formulations are derived based on the classical plate theory (CPT) considering the von Karman geometrical nonlinearity taking the physical neutral plane as the reference plane. The partial differential formulation is separated into two sets of ordinary differential equations using the extended Kantorovich method (EKM). The stability equations and boundary conditions terms are derived according to Trefftz criteria using the variational calculus expressed in an oblique coordinate system. Novel multi-scale plots are presented to show the linear relations between the critical temperatures under various temperature distributions. The cr...
Experimental values of viscosity are presented for the mixtures of 7-[2,2-(1-phenylidene amino)-1... more Experimental values of viscosity are presented for the mixtures of 7-[2,2-(1-phenylidene amino)-1,3,4 – (Thiadiazole5-yl)thio acetamido]Desacetoxy cephalosporanic Acid [PATDCA] with water over the whole mole fraction range at 298.15 , 308.15 , 318.15 and 328.15 K.The data were used to calculate excess viscosity , ∆ln η and excess Gibbs energy of activation of flow ,∆G *E .Both ∆ln η and ∆G *E show a significant positive deviation from ideal mixing behavior over the whole mole fraction range and decreased with increasing temperature . The results have been discussed in terms of the nature of solvent – solute interaction in the mixture. Introduction: Knowledge of mixing properties of binary mixtures has relevance in theoretical and applied areas of research such results are needed for design processes in chemical and petrochemical industries . Some drugs such as morpholine finds application as an extractant agent for aromatic hydrocarbons from petroleum cuts [1-3]. Therefore an unders...
This work reports a modelling method of functionally graded materials (FGM) using ANSYS APDL. ANS... more This work reports a modelling method of functionally graded materials (FGM) using ANSYS APDL. ANSYS, as many other analysis software packages, does not provide a direct way to model variation in material properties as a function of position. However, ANSYS offers the option of temperature dependent properties; and ANSYS also offers the ability of assigning temperature values according to the position; joining these two abilities offered by ANSYS, the material properties would be position dependent. In this work, using ANSYS APDL, dummy thermal loads are used to obtain FGM distributed properties. The presented modelling method is explained and then applied to some case study of static analysis to verify its accuracy by comparing its results with the analytical solution from the case study source. The main advantage of such a method is its simplicity and ease; it does not require deep knowledge of mathematical models of FGM and delivers high accuracy. Although in this study ANSYS APDL...
International Journal of Design & Nature and Ecodynamics, 2021
In this paper, texts were experimentally transmitted by pulse width modulation (PWM) using an und... more In this paper, texts were experimentally transmitted by pulse width modulation (PWM) using an underwater wireless optical communication system (UWOC) in a channel containing water of varying salinity as a result of changes in the concentration of sodium chloride (NaCl). Mathematical equations are used using a MATLAB program to compare theoretical and practical results at different slop angle (θ0). (NaCl) concentration was changed from (0% w/v) to (90% w/v) to achieve different salinity of water (i.e., from clear water to turbid water). A diode laser with a power of 30 mW and a wavelength of 532 nm has been employed in the transmitter. The experimental results show that the extinction coefficient or the overall attenuation C(λ) is equal to (0.083/m) in the water containing a low concentration of (NaCl) which is consistent with pure seawater. Additionally, the obtained optical power (PR) and the signal to noise ratio (S/N) decreases to (27.6) mW and (23.99) dB, respectively. Furthermor...
The extended Kantorovich method (EKM) is implemented to numerically solve the elastic buckling pr... more The extended Kantorovich method (EKM) is implemented to numerically solve the elastic buckling problem of thin skew (parallelogram) isotropic plate under in-plane loading resting on the Pasternak elastic foundation. EKM has never been applied to this problem before. Investigation of the EKM accuracy and convergence is conducted. Formulations are based on classical plate theory (CPT). Stability equations and boundary conditions terms are derived from the principle of the minimum total potential energy using the variational calculus expressed in an oblique coordinate system. The resulting two sets of ordinary differential equations are solved numerically using the Chebfun package in MATLAB software. In-plane compression and shear loads are considered along with various boundary conditions and aspect ratios. Results are compared to the analytical and numerical solutions found in the literature, and to the finite element solutions obtained using ANSYS software. The effects of the skew angle, stiffness of elastic foundation, and aspect ratio on the buckling load are also investigated. For plates with zero skew angle, i.e. rectangular plates, with various boundary conditions and aspect ratios under uniaxial and biaxial loading resting on elastic foundation, the single-term EKM is found accurate. However, more terms are needed as the skew angle gets bigger. The multi-term EKM is found accurate in the analysis of rectangular and skew plates with various boundary conditions and aspect ratios under uniaxial, biaxial, and shear loading resting on elastic foundation. Using EKM in buckling analysis of thin skew plates is found simple, accurate, and rapid to converge.
Engineering Science and Technology, an International Journal, 2020
Multi-term extended Kantorovich method (MTEKM) is used to solve the bending problem of thin skew ... more Multi-term extended Kantorovich method (MTEKM) is used to solve the bending problem of thin skew (parallelogram) functionally graded plate resting on the Winkler elastic foundation under uniformly distributed transverse load. Formulations are based on the classical plate theory (CPT) with the physical neutral surface is considered as the reference plane. Various configurations of clamped, simply supported and free edges are considered. By implementing the concept of Galerkin's weighted residual method, the fourth-order partial differential governing equation and boundary conditions are converted into two sets of ordinary differential equations (ODE), which are then solved numerically using ''Chebfun" numerical computation package. Convergence and accuracy of MTEKM are investigated. Results obtained with MTEKM are compared to finite element method (FEM) solutions. FEM has been implemented using ANSYS software, in which the plate is modeled with shell elements, while the elastic foundation is modeled as a pair of contact/target elements. In addition, the effects of both the Winkler foundation stiffness and material power index have been investigated. Applying MTEKM in bending analysis of thin skew plates offered more accurate results than the single-term EKM but with the cost of more computation time but still provides simplicity and rapid convergence. It is found that MTEKM well suits the bending problem of skew FGM plates resting on elastic foundation.
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