Sylvester Abonyi - Academia.edu (original) (raw)

Papers by Sylvester Abonyi

Zenodo (CERN European Organization for Nuclear Research), Sep 21, 2023

International Journal of Trend in Scientific Research and Development, 2018

A new hybrid synchronous reluctance machine capable of ultra-high Xd/Xq ratio output power has be... more A new hybrid synchronous reluctance machine capable of ultra-high Xd/Xq ratio output power has been studied. A d-q model (voltage and flux linkage) of the hybrid synchronous reluctance machine has been idealized and developed. Also the impedance and current loci from steady state analysis of the machine was obtained. The effect of capacitor loading in the auxiliary winding was investigated. The power factor and torque developed in the hybrid synchronous reluctance machine was compared with the conventional synchronous reluctance machine. The hybridized synchronous reluctance machine improved the major constraints of conventional reluctance machinelow power output and poor power factor due to low ratio of direct to quadrature axis reactance (Xd/Xq). To achieve this two elemental synchronous machines was conceived. Both were internally wound with identical winding in the stator. The rotor of one of the synchronous reluctance machine component is round while the other has a salient pole. Both machine halves were mechanically coupled together. One set of the winding of both machines were connected in series and fed from the main while the other set was also connected in series (but transposed between the two section of the of the machine) and then connected to a balanced three phased variable capacitance load. It was the capacitance loading of the auxiliary winding makes the overall Xd/Xqratio of the hybrid machine to be variable that can theoretically attain values between zero and infinity. This translates to ultra-high output and unity power factor.

This work presented the design and construction of a manually powered lawn mower as well as the s... more This work presented the design and construction of a manually powered lawn mower as well as the stress analysis of the blade. The solid model of the lawn mower design was done using Solid works software. The materials utilized for the construction were selected following standard material selection processes. The required cutting speed was achieved by proper gear arrangement which transferred the rational motion of the wheels to the blade, consequently increasing the speed by about 300%. The average cutting capacity of the lawn mower is 62.48 m 2 /hr. The stress analysis on the blade using the simulation tool of the solid works software gave a maximum von mises stress that is 252 times less than the yield strength of the blade material. Also, a maximum deformation of 0.00271mm obtained from the analysis is quite infinitesimal hence, the blade can withstand both stress and deformation resulting from the cutting operation.

Hybrid Advances

Reinforced composite is a preferred choice of material for the design of industrial lightweight s... more Reinforced composite is a preferred choice of material for the design of industrial lightweight structures. As of late, composite materials analysis and development utilizing machine learning algorithms have been getting expanding consideration and have accomplished extraordinary upgrades in both time productivity and expectation exactness. This review encapsulates recent advances in machine learning-based design of reinforced composite during the last half-decade. It summarizes the limitations of traditional methods of reinforced composite development and presents a detailed protocol of machine learning in composite materials technology; implementation of machine learning algorithms in reinforced composite material design was covered, with an emphasis on the importance of data hygiene. Machine learning integration in material and process selection, and data sourcing techniques for machine learning-based design were also examined. The evaluation also looked at emerging digital tools and platforms for implementing machine learning algorithms. In addition, an essential effort was made to identify research gaps and define areas for further research. This review is indeed designed to provide some direction for future research into the use of machine learning for composite material design.

| IRE Journals, 2023

It is an undisputable fact that power is highly essential in all areas of human existence. Energy... more It is an undisputable fact that power is highly essential in all areas of human existence. Energy which is simply defined as the ability to do work is held to be fundamental to every existential element on earth and even beyond by both the science and the orthodoxy. Human activities on earth in the form of research, experiment and accidents, across centuries had led to the discovery and consequent categorization of power which is a derivate of energy, into different forms such as Electrical, Mechanical, Chemical etc. powers. Basically, energy is the building block, upon which power is constituted, and by quantum theory of matter, all elements, things or object stems from a conglomeration of several individual particles each having a given amount of energy subject to its mass and momentum

International Journal of Trend in Scientific Research and Development, 2023

The design of a universal sieving machine was explored to meet the diverse needs of sieving appli... more The design of a universal sieving machine was explored to meet the diverse needs of sieving applications across various industries. The machine incorporates various mechanisms to enable it to handle different types of materials (e.g., cassava flakes, Sand, Flour, etc.) and sieve them to desired particle sizes. Careful component selection and procurement were undertaken to ensure compatibility, quality, and availability. The machine's performance was evaluated by conducting various tests, including the sieving of different materials (sand and granulated cassava) with varying particle sizes. The results showed that the Universal Sieving machine achieved excellent sieving accuracy and efficiency of 98%, indicating its potential for use in industrial and research settings. This project offers a cost-effective solution to the challenges of sieving a diverse range of materials and has significant implications in the fields of food processing, mining, and pharmaceuticals.

Journal of Electrical and Electronics Engineering

Majority of the appliances around us use alternating current (AC) power while the Photo Voltaic (... more Majority of the appliances around us use alternating current (AC) power while the Photo Voltaic (PV) modules produce Direct current (DC) power. Therefore, the conversion of DC power to AC power is required before it can be used for running such appliances. In a general note, the power inverter is an electronic device or circuitry that changes direct current (DC) to alternating current (AC). This conversion can be achieved either by transistor or by Silicon Controlled Rectifiers (SCRs) [1]. The input voltage, output voltage and frequency, and overall power handling capacity depend on the design of the specific device or circuitry. For low and medium power outputs, transistorized inverters are suitable but for high power output, silicon controlled rectifiers (SCRs) should be used. Strictly speaking, inverters can be broadly classified into single (one) level inverter and multi (more than one) level inverter. Multilevel inverter as compared to single level inverters has advantages, as they can operate on several voltage levels with minimum harmonic distortion. Though in our recent inverter topology, the multilevel began with the three level inverters,s the conventional, two level inverter has many limitations for high voltage and power application. It produces an output parameters (voltage or current) with level either zero or +ve/-ve, which is inferior to that of a multilevel counterpart with smoother output voltage with n number of possible values. In contrary to the multilevel inverter, the 2-level inverter counterpart produces output parameter with larger harmonics, but on the other hand, it has less component and easy to control. In high power application the 2-level inverter however has some limitations in operating at high frequency, due to switching losses and constraints of device rating [2].

International Journal of Trend in Scientific Research and Development , 2023

With non-availability of the required equipment, teaching engineering drawing to a class of over ... more With non-availability of the required equipment, teaching engineering drawing to a class of over 1000 students and retaining their interests and attention from the beginning to the end of a lecture period was of big concern to the engineering drawing courses lecturers in the Faculty of Engineering, Nnamdi Azikiwe University, Awka. This work is aimed at designing and developing animated Microsoft Office PowerPoint teaching applications named 2-D Computer-Aided Drafting Applications (2-D CADA) that eliminate this problem. This paper presents a sample of the Applications which demonstrates clearly to the audience's pleasure how to mount, set and hold a drawing sheet on a drawing board before actual drawing commences. It also shows how to manually draw boarder lines on the drawing sheet. Similar programs can be written and used to show to engineering students how to manually draw most of the figures specified in their schools' curricula using engineering drawing instruments. Many of this Application have been written on various topics in engineering drawing in line with the global trend of drudgery reduction in man-machine systems. These Applications are already being deployed in teaching engineering drawing in the

Macro-structural and mechanical properties of tortoise shells of Nigeria indigenous specie were s... more Macro-structural and mechanical properties of tortoise shells of Nigeria indigenous specie were studied to reveal its evolution as a natural load-bearing protective amour. The shell is revealed in this study to be a natural sandwich composite made of kerat dorsal cortex, porous bone and ventral cortex. Indications of delamination which help the tortoise to absorb shocks were seen in the keratin. The dorsal and ventral cortexes were seen to be load bearing members with distribution of fibers in a manner t sustain dead load. The porosity seen in the middle porous layer ensures that the carapace is not too heavy for the tortoise to carry thus guarantees ease of locomotion, strength and damping. The average porosity of the studied shells is determined to b 31.0425% which as expected is smaller than the value 48.9% reported for porosity of shell of the turtle Terrapene Carolina in literature. The suture of the shell is revealed to house a zigzag interlocking design that allow slight deformation of the shell under light loads required for respiration, locomotion and metabolism but stiffen under excessive deformation. Stiffness of two specimens was determined to be 1 6 Trend in Scientific Research and Development

International Journal of Trend in Scientific Research and Development, Oct 12, 2020

A research on the drying characteristics of aerial yam using convectional hot air was done. The r... more A research on the drying characteristics of aerial yam using convectional hot air was done. The raw unblanched and blanched samples were dried using convectional hot air. Fan speed, temperature and slice thickness were varied to determine the change in moisture content. The Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) were done to determine the functional groups and surface morphology respectively for each sample. FTIR results revealed the presence of some important functional groups such as esters, ethers and nitro-compounds, and shows that drying at this temperature (40-70oC) does not alter the nutrient components of this variety of yam. The SEM results showed that important cells were not destroyed at the drying temperature. Batch studies on the drying process also showed that increase in temperature and air speed increased the drying process, but decreases with increase in slice thickness. Effect of drying rate on the sample showed that drying rate increase with increase in temperature and air speed but decrease with increase in slice thickness. After 90 minutes of drying, the drying rate of the 2 mm slice thickness was 0.353 g/g.min for drying of aerial yam while for 4 mm and 6 mm slice thickness, the drying rate were 0.261 and 0.169 g/g.min respectively, for effect of drying rate on sample thickness. It showed also that blanched aerial yam samples had a higher drying rate than the unblanched aerial yam sample at the same conditions. Therefore, the economic advantages of this yam species can be optimized by blanching.

International Journal of Trend in Scientific Research and Development, Jun 26, 2021

This report contains the design, fabrication and performance analysis of a shock absorber spring ... more This report contains the design, fabrication and performance analysis of a shock absorber spring compressor. The detailed data of the different parts was presented. The materials selected for each part, the reason for selecting that material and the design of the different parts of the shock absorber compressor spring was carried out. The manufacturing processes involved was presented. From the design it was established that deflection in the spring decreases with reduction in the stresses applied to the spring. The test result of the fabricated shock absorber compressor spring shows that the tool was very efficient in extracting the spring during the repair process with danger of harming the technician working with the tool. Sylvester Emeka Abonyi | Anthony A. Okafor | Nawdike Emmanuel Chinagorom "Design and Fabrication of Shock Absorber Compressor Spring" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-...

Electronically Controlled Braking system is an automobile safety system that allows the wheels on... more Electronically Controlled Braking system is an automobile safety system that allows the wheels on a motor vehicle to maintain tractive contact with the road surface according to driver inputs while braking, preventing the wheels from locking up and avoiding uncontrolled skidding. Generally it offers improved vehicle control and decreases stopping distances on dry and slippery surfaces. It also modulates the brake line pressure independent of the pedal force, to bring the wheel speed back to the slip level range that is necessary for optimal braking performance.

Neuroscience Letters, 2008

Altered Notch signaling seems linked with medulloblastoma (MB) formation and resveratrol exhibits... more Altered Notch signaling seems linked with medulloblastoma (MB) formation and resveratrol exhibits anti-medulloblastoma effects. However, the influence of resveratrol in Notch signaling of MB cells has not been described. This issue was addressed here by checking Notch1 and Notch2 statuses in three MB cell lines with and without resveratrol treatment. Notch1 and Notch2 were detected in the cytoplasm of three cell lines under normal condition, which were up-regulated by resveratrol along with differentiation, apoptosis and enhanced Hes1 nuclear translocation. Nevertheless, blockage of Notch enzymatic cleavage with gamma-seacretase inhibitors, DAPT and L-685,458, neither interrupted resveratrol-caused cellular events nor affected MB cell growth. These results demonstrate that Notch signaling has little relevance with resveratrol-induced differentiation and apoptosis and may not be a universal critical factor of MB cells.

IET Electric Power Applications, 2015

ABSTRACT Analytical and experimental studies of a hybridised synchronous reluctance machine with ... more ABSTRACT Analytical and experimental studies of a hybridised synchronous reluctance machine with a variable X-d/X-q ratio characteristic is the subject of this study. The machine comprises a round rotor and a salient pole machine element that is mechanically coupled together and integrally wound. There are two sets of poly-phase windings in each stator. The windings of one of the sets are transposed between the two sections of the machine. Either set of the windings may be connected to the supply while the other feeds a balanced capacitance load. It is shown that by tuning of the capacitance load that the Xd/Xq ratio varies theoretically from zero to infinity at very good power factors. The machine characteristics were verified using the generalised two-axis theory and validated by experimentation. The experimental and analytical results obtained show good agreement. Saturation was investigated by using the variation of the d-axis inductance with machine loading. A set of rotor windings may be introduced for the purpose that the machine be self-starting and self-synchronising as a motor. The rotor field windings when fed with dc, will make the machine also capable of operation as a stand-alone salient-pole generator. For this purpose, it was shown that for a very high saliency ratio, reluctance power can be considerably higher than the excitation power.

Date of publication (dd/mm/yyyy): 02/06/2020 Abstract – The research was carried out with the aim... more Date of publication (dd/mm/yyyy): 02/06/2020 Abstract – The research was carried out with the aim of statistically investigating the effect of shielding gas on the tensile properties of high carbon steel weldment using Tungsten Inert Gas (TIG) in combination of argon and carbon (iv) oxide gases. TIG welding technique was used to join the weld. An experiment was designed using the design expert software 10.0.1 version, which developed a combined mixture design of twenty seven experimental runs. The combined and process factor design was applied to statistically analyze the effect of shielding gas on the yield strength of the weldment. The statistical evaluation consists of mixture and process variable, having current, voltage, argon and carbon (iv) oxide gases as input parameters and yield strength as the response. The result obtained from the design summary gave minimum value of tensile strength as 280MPa and maximum 485MPa while mean value was 369.82 and standard deviation of 46.94...