Journal of Engineering Studies and Research
JESR is a quarterly scientific journal edited by an Editorial Office from the Engineering Faculty – “Vasile Alecsandri” University of Bacau. It contains the most recent theoretical and experimental studies concerning the topical and perspective problems in the conception and manufacturing fields of the technological plants and equipments. JESR in an Open Access Journal - the journal allow readers to read, download, copy, distribute, print, search, or link to the full texts of its articles and allow readers to use them for any other lawful purpose (according to: BOAI Definition of Open Access). The papers published in JESR journal are licensed under a Creative Commons Attribution 4.0 International License.
INCREASING THE ENERGY EFFICIENCY OF A POWER TRANSFORMATION AND DISTRIBUTION STATION
Substations are the main elements of an energy system that must ensure evacuation of power produced in the power plants, connection of lines to transit the power, distribution electricity to consumers. Reliability of a substation is essential for the role it plays in the energy system. In this paper are determined the energy losses in power lines and transformers associated with an electrical distribution station. The real operating regime is analyzed and an optimal model is established to improve the energy efficiency of the power station.
substation, optimization, distribution, energy efficiency
Copyright (c) 2026 Journal of Engineering Studies and Research
EXPERIMENTAL STUDY OF POWER GENERATION UTILIZING HUMAN EXCRETA
This study examines the potential of generating electricity from human excreta using biogas technology 1 m3 biogas plant was implemented and experiment upon with human excreta collected from DELSUTH, to evaluate its performance. Anaerobic process was employed in biodegradation of excreta in digester within 30 days. The Biogas produced was scrubbed to eliminate CO2, H2S, and stored in gas holder. Methane yield was used to fuel modified generator to determine its output power. The results indicate 0.450 m3 daily of biogas produced runs 3 KVA generator for 47 minutes with 1.8 KW load. The biogas generator worked perfectly without knocking during experiment period.
biogas, human excreta, anaerobic digestion, methane, hybrid carburetor, renewable energy
HARMONIC ANALYSIS OF A SUB-DISTRIBUTION NETWORK: THE CASE OF A NIGERIAN FEDERAL UNIVERSITY
This paper investigates the harmonic distortion level in sub-distribution networks in a university community. Quantitative analysis of load data was used to model the distribution network using occupancy harmonic source modeling. Phone (GSM charging), Compact Florescent Lamp (CFL), Laptop (LAP), Personal Computer (PC), and Television (TV) were discovered to be the highest contributors of harmonics with 16%, 14%, 12%,11%, and 11% respectively. The results showed that four (4) units of the 19 PCCs contributed about 56 % of the total harmonic distortion level. This research underscores the importance of addressing harmonic distortion in academic institutions, contributing to better operational performance.
harmonic distortion, harmonic ranking, non-linear loads, harmonic analysis
GEOTECHNICAL POTENTIALS OF THE ALUMINIUM DROSS-LIME TREATED LATERITIC SOIL FOR ROAD APPLICATIONS
Increasing production of aluminium dross (AD) is posing disposal problems, causing serious pollution. In this study, the effectiveness of this material and hydrated lime (HL) in enhancing geotechnical features of A-7-6 and CH classified soil was evaluated. The soil was admixed with 0-20 % AD and 0-9 % HL by mass of the soil, various geotechnical tests were conducted on soil specimens. A combined mixture of 6 - 9 %HL and 20 %AD that achieved results which fall within the minimum UCS of 0.75 - 1.5 MPa specified for sub-base layer of medium to heavy traffic roads is recommended for strength enhancement of the A-7-6 soil.
aluminium dross, geotechnical properties, hydrated lime, lateritic soil, strength characteristics
CONSTRUCTIVE-FUNCTIONAL AND FEM ANALYSIS OF AN OIL UOP 12 C1 PUMP
The paper presents the constructive-functional and FEM analysis of an oil UOP 12 C1 pump, aiming at three-dimensional modeling of the assembly in Autodesk Inventor program, as well as the finite element analysis of the created graphical model, determining the minimum and maximum values for the state of stresses and displacements. The stages of creating the 3D model, the commands used in the modeling process, as well as the simulation conditions applied in the FEM analysis are detailed. The paper also includes a comparative analysis of the states of stresses and displacements of the pump, depending on the material used - aluminum or steel.
oil pump, Autodesk Inventor, FEM analysis
TECHNO-ECONOMIC FEASIBILITY AND SENSITIVITY ANALYSIS OF OPTIMAL DESIGN OF HYBRID GRID-CONNECTED MICROGRID CONFIGURATION FOR SUSTAINABLE AND RELIABLE ENERGY
To mitigate greenhouse gas emission and cost of electricity at Mewar University, this study proposes an optimized microgrid design integrating PV solar panels, wind turbines, diesel generators, and grid connectivity, utilizing HOMER software for optimization. The system would purchase 3,827,194 kWh annually from the grid during low renewable output periods and sell 167,761,193 kWh annually during surplus production. This design achieves a levelized cost of energy (LCOE) of $0.00146/kWh and a return on investment (ROI) of 10.1% (approximately 9.9 years), with total component expenditure of $16,207,384, covering capital investments, operations and maintenance (O&M), and fuel costs. Solar photovoltaics contribute 83% of the annual production, with the remaining 17% from the grid and wind turbines, establishing the system as cost-effective and environmentally friendly due to its heavy reliance on renewable energy sources (RES). Comprehensive feasibility, technical, economic and sensitivity analysis confirm the viability of implementing this proposed system.
Renewable energy sources (RES), Levelized cost of energy (LCOE), HOMER software, Economical analysis, sensitivity analysis, optimization, Microgrid
EFFECTS OF SODIUM, POTASSIUM AND CALCIUM CHLORIDE SALTS ON UNDERWATER VISIBLE LIGHT COMMUNICATION PERFORMANCE AND THEIR PRESENCE IN SOME WATER BODIES OF SOUTHWEST NIGERIA
The Salinity is one of the attributes of water that affects underwater wireless optical communication (UWOC) and requires continual investigation. This study investigates the effect of sodium, potassium and calcium chloride salts on transmission of visible light in water via spectroscopy for underwater communication, as well as the presence of these salts in seven water bodies of Southwest Nigeria. Single-salt solutions of each type with varying concentrations were prepared, and their physiochemical properties were measured, as well as their visible light absorbance spectra, from which performance of UWOC for each salt solution at three wavelengths was investigated by simulation using OptiSystem. Water samples were taken from three rivers, two lagoons, and the Atlantic Ocean in Southwest Nigeria and the concentration of the three cations and chloride ion in them were measured as well as their absorbance spectra. For the single-salt solutions, higher absorbance at shorter wavelengths was observed with an increase in salt concentration for sodium and potassium chloride solutions, but calcium chloride solution shows higher absorbance towards longer wavelengths. UWOC simulation results showed that the achievable maximum link distance reduces with salt concentration, varies with wavelength, and is least in calcium chloride solution. For the water bodies, the rivers have low values of salinity and absorbance, while high values were obtained for the lagoons and the Atlantic Ocean. Moreover, their average absorbance showed strong correlations with concentration of calcium and chloride ions than with sodium and potassium ions.
salinity, sodium chloride, potassium chloride, calcium chloride, absorbance, underwater wireless optical communication
ANALYSIS OF THE INFLUENCE OF CONCRETE AND CLAY SPEED BUMPS ON HEAVY-DUTY TRUCK LEAF SPRINGS
This study examines the structural behavior, fatigue lifespan, and damping characteristics of heavy-duty truck leaf springs subjected to concrete and clay speed ramps under various induced loading scenarios. The findings showed that extended leaf springs positioned at the top experience diminished stress levels compared to their shorter counterparts located at the bottom. This research suggests that elongated leaf springs endure substantial bending stress and deformation attributable to the elevation of the speed ramp and the imposed loading capacity, which in turn impacts the fatigue lifespan of the leaf springs under induced loading conditions.
heavy-duty truck, leaf springs, speed ramp, rear-axle
ENVIRONMENTAL LIFE CYCLE ASSESSMENT OF SMOKED FISH PRODUCTION: A CASE STUDY OF THE UNIVERSITY OF IBADAN FISH FARM
The study aimed to carry out a life cycle assessment (LCA) of the production and processing of smoked fish using the University of Ibadan Fish Farm as a case study to identify environmentally detrimental production and processing hotspots. The LCA used cradle-to-gate approach which involves the operations from breeding/hatching to the packaging of smoked fish. Four scenarios were drawn for assessing the impact by varying the energy and material resources. Six impact categories were measured for all four scenarios with Global Warming Potential (0.639 kg CO2-Eqiv.) having the highest impact while Human Toxicity Cancer Effect recorded the least impact (3.463e-11 CTUh). At the end of this LCA study, it was recommended that renewable energy sources as well as energy from bio-waste should be explored for the smoking kilns to achieve cleaner production.
life cycle assessment, global warming, acidification potential, smog air, smoked fish production and processing
COMPARISON AND EFFECTIVENESS OF SLIP MODE FREQUENCY SHIFT AND SANDIA FREQUENCY SHIFT ACTIVE METHODS FOR ISLANDING DETECTION IN SINGLE-PHASE GRID-CONNECTED PHOTOVOLTAIC SYSTEMS
This paper offers a comprehensive comparison for the effects of two most important active anti-islanding detection methods which are the slip mode shift frequency (SMS) and Sandia frequency shift (SFS). The comparison is proved in detail through the simulation of the proposed single-phase photovoltaic (PV) system in the Matlab/Simulink. The obtained results show that islanding operation can be successfully detected and prevented using the studied active methods with adequate values for grid power and local load quality factor. In addition, adequate parameters of each method lead to reduce the non-detection zone (NDZ) and prevent the failure of the studied methods.
active methods, islanding, inverter, photovoltaic (PV), Sandia frequency shift (SFS), slip mode frequency shift (SMS)
BEHAVIOUR OF OIL PALM BROOM FIBRE REINFORCED CONCRETE
Fiber reinforced concrete was developed by incorporating discrete fibers into the concrete mass to combat the brittle reaction of concrete. The durability of natural fibers such as oil palm broom was established through an experimental investigation in which the fiber was treated to an alkalization-related treatment procedure. The research is based on the investigation of the use of Oil Palm Broom Fibres (OPBF) in structural concrete to enhance the mechanical characteristics of concrete. The OPBF were subjected to an alkali treatment with the use of sodium hydroxide of 4 %, 6 %, 8 % and 10% with removal times of 1 hr, 2 hrs, 8 hrs and 24 hrs respectively. The flexural strength of OPBF concrete was determined after 28 days where the treated fibres were included in fresh concrete mix. The discrete OPBF of 75 mm length were washed and dried in open air and randomly included in the concrete at 0.3 % of the volume of the beam size 100 x 100 x 600 mm with mix ratio of 1:2:4 and water-cement ratio of 0.55 to assess the suitability and durability of the fibre in concrete. It was observed that the rate of water absorption of the treated fibres increase compared to untreated fibres and the treated OPBF with lkalization improves the flexural strength of concrete beam at a concentration of 6 % NaOH for a duration of 1hr and the SEM images of OPBF cross section shows dispersed cavities. The OPBF is appropriate for use in concrete as a brief discrete fibre reinforcement for low cost construction.
alkalization, concrete, durability, flexural strength, oil palm broom fibre
The present paper examines the genesis and trend of orange wines, as well as the potential of the local market to integrate this type of wine and the role of sustainability and durability in strengthening the creation of biodynamic wines. The research focused on the investigation of the local white grape variety Viorica from the Purcari area, examining the grapes, the procedures used to get the raw material wine intended for the production of Orange wine, and wines from the 2020 and 2022 harvests. After getting the wine raw material, the organoleptic properties were analyzed and the key parameters were evaluated, which revealed that they correspond to the documents in force.
grapes, maceration - fermentation, diagram, orange wine, Qvevri, amber wine, local market, sales
REGRESSION ANALYSIS OF FACTORS AFFECTING ZINC RECOVERY IN ROTARY KILNS
With the rapid increase in global industrialization, the demand for zinc constantly increases while primary zinc resources gradually decrease. This situation makes the recovery of zinc from secondary sources a strategic priority from a circular economic perspective. Electric arc furnace (EAF) dust, an essential iron and steel industry waste, is a valuable secondary resource due to its high zinc content. Therefore, zinc recovery is an attractive option, given its low production cost. This study conducted an experimental analysis of the zinc recovery process from EAF dust in rotary kilns. Operational data obtained from an industrial-scale plant were used. The data set included EAF dust amount, iron content in EAF dust, lime content, coal used, slag amount, and zinc grade in slag. Multiple Linear Regression (MLR) analysis was applied to determine the relationships between the parameters. The MLR analysis calculated the multiple correlation coefficient (R) as 0.661876, and statistically significant relationships were determined between process parameters and slag formation. The findings provide a systematic and innovative approach for optimizing process parameters and controlling slag formation in industrial-scale zinc recovery processes. The analysis results indicated that raw material quantities and iron content in EAF dust significantly affect slag formation, contributing to zinc recovery efficiency and waste minimization. The developed model allows the systematic understanding and control of the effects of process parameters on slag formation while also providing a solid basis for future optimization studies.
regression analysis, multiple linear regression, zinc recovery, EAF dust, rotary kiln
PARAMETRIC STATISTICAL SIGNIFICANCE OF LEAD (II) IONS ADSORPTION BY RICE HUSK IN AQUEOUS SOLUTIONS
Batch experiments were performed to determine how Pb (II) ion adsorption was affected by contact time, adsorbent dosage, temperature, and pH. Adsorption increased with higher adsorbent doses and decreased with higher adsorbate doses. Time speeds up the adsorption process, with pH 6 and 650 °C showing the highest levels of adsorption. The Langmuir and Dubinin-Radushkevic isotherm models best fitted the sorption data, with R2 values of 0.995 and 0.9956 and standard errors of regression of 1.8209 and 0.0298, respectively. The pseudo-first order kinetic model best captured the kinetics. Analysis of Variance (ANOVA) and the Bonferroni-Holm Posthoc significance test showed that the adsorption was statistically and parametrically justified.
Rice husk, ANOVA, Adsorption capacity, Removal efficiency
AN EVALUATION OF YELLOW OLEANDER (THEVETIA PERUVIANA) SEED OIL AS A CUTTING LUBRICANT USING THE EXAMPLE OF MEDIUM CARBON STEEL FOR TURNING ON THE LATHE MACHINE
The yellow oleander (YO) is a notable plant of great technological importance. It grows naturally and is grown agriculturally widely and abundantly in Nigeria and many other countries around the globe. The potential of using pure oil extract from YO seed as a more environmentally friendly alternative cutting lubricant to the conventionally and widely used soluble oil was investigated in terms of some basic physicochemical properties, work cooling, and surface finishing performance using, for example, medium-carbon steel as the workpiece in turning on the lathe machine. The kinematic viscosities, pH values, unsaturated oleic acid contents, free fatty acid contents, flash points, pour points, and chloride contents, as well as the cooling and surface finishing capabilities of the steel by the two oils, were experimentally evaluated. The Soxhlet technique was used to extract the YO seed oil. The evaluated kinematic viscosity at 100 oC, pH value, unsaturated oleic acid content, free fatty acid content, flash point, pour point, and chloride content of the YO seed oil through various ASTM and other standard methods were 21.13 cSt, 8.66, 31.23%, 0.91%, 191 oC, 1 oC, and 0.16%, respectively, while the respective values for soluble oil were 19.27 cSt, 6.51, 20.62%, 2.10%, 171 oC, 3.18 oC, and 0%. Comparative analyses of the YO seed oil and soluble oil values indicate a lower ability of YO seed oil to flow than soluble oil, an insignificant corrosivity difference between the two oils, better lubricity of YO seed oil than soluble oil, less tendency of YO seed oil to oxidize and become rancid than soluble oil, less proneness of YO seed oil to fire hazards than soluble oil, better suitability of YO seed oil for cold regions than soluble oil, and higher sterility and tendency towards increased emulsion life of YO seed oil. Turning experiments indicate that the two oils have similar cooling and surface finishing effects on medium-carbon steel. The overall information and analyses suggest that YO seed oil can be extracted sustainably in large quantities in many countries around the world, including Nigeria, and used effectively as a more environmentally friendly alternative lubricant to soluble oil in metal cutting operations such as turning medium-carbon steel on the lathe machine.
medium carbon steel, lathe machine, cutting lubricants, YO seed oil, potentialities, soluble oil, comparative performances
ANALYSIS OF CRANKSHAFT DEFECTS FROM AUTOMOBILE INTERNAL COMBUSTION ENGINES AND THEIR CLASSIFICATION
The following research investigates the main damages that the crankshafts from internal combustion engines may experience. Operational damage is associated with significant changes in shape, dimensions and mutual arrangement of their surfaces. Defects are classified as natural (primary) and consequential (secondary), and are caused by failures in other components that make up the engine.
ASPECTS REGARDING THE STUDY OF HYDRAULIC AND MECHANICAL PARAMETERS OF A ”SPIDER CRANE” SYSTEM
Since it is acknowledged that transport and lifting installations play an extremely important role in industry, construction, and the extractive field, as well as in the mechanization of loading-unloading works, the movement of equipment or materials, special attention is paid to the growth and diversification of such installations at the level of the most advanced technologies. The paper presents the operating principles and characteristics of a lifting and transport installation known as a ”Spider Crane”. This installation is considered a more cost-effective and efficient alternative to traditional cranes for works where lifting requirements are below certain limits and significant heights. Thus, an analysis of the hydraulic lifting system is carried out, based on the calculation of hydraulic fluid flows for the drive pumps, the specific speeds and forces of the hydraulic cylinders, a mechanical analysis of the clamping system with hook, as well as a finite element analysis of some mechanical and hydraulic components.
”Spider Crane”, lifting system, hydraulic pump, hydraulic motor, hook, FEM
ASSESSING THE STATIC OF SOIL-STRUCTURE INTERACTION ON THE BEHAVIOR OF REINFORCED CONCRETE STRUCTURES: A MECHANO-FIABILISTIC APPROACH
Assuring the lifespan and safety of reinforced concrete (RC) structures is essential, given the potential risks of malfunctions such as premature failure. To meet this challenge and construct durable, cost-effective structures, consideration of soil-structure interaction and inclusion of soil resistance elements in mechanical evaluations are critical. This study uses a numerical model based on the finite element method to examine the impact of inherent non-linearities in the soil on the performance of a three-span RC beam. The numerical study highlights the crucial role of soil geotechnical parameters. It clarifies the complex static non-linear effects that result from the interaction of the soil and the structure. The work also introduces a mechano-fiabilistic method, emphasizing how soil behavior in traditional RC structure designs is unexpected and non-linear. The sensitivity of structural safety to changes in soil parameters is revealed by integrating static modeling of the soil-structure interaction into the mechanical model of a continuous beam. This study emphasizes how important it is to incorporate soil-structure interaction into RC structure designs for precise, dependable, and economical results.
static analysis, nonlinear behavior, soil-structure, soil uncertainties, reliability
GEOMECHANICAL CHARACTERISTICS OF CONTINUOUS SANDSTONE CONCRETE BASED ON ECOLOGICAL CEMENT WITH A KIMBUNGU BASALT SUBSTITUTION
Concrete is a geo-material highly used throughout the world. It is made up of granules, cement, and water. It is a composite material of which aggregates are coated by hydrated cement that plays a binder role. The current production of cement factories is estimated to 4.2 billion of tons a year [1]. Its production results in CO2 emissions. Referring to yearly produced cement quantity, it is obvious that it poses the environmental pollution. A previous study emphasized the possibility of creating composite cement of 75 % clinker, and 25% basalt [2]. Throughout this study, we discovered that the strength of this cement-based concrete is slightly lower than 2 days, but 28 days and 90 days higher than the control concrete composed of the same materials as the current Portland cement.
continuous concrete, Inkisi’s sandstone, Mukimbungu’s basalt, compressive strength
TRIP GENERATION MODELING OF ILORIN CITY, NIGERIA, USING GIS AND ARTIFICIAL NEURAL NETWORK
Ilorin's traffic situation, while not as severe as larger cities like Lagos, Ibadan, and Port-Harcourt, is showing signs of bottlenecks and congestion. Travel demand modeling is important for effective transportation planning. This study develops Artificial Neural Network (ANN) trip generation (production and attraction) models using household and trip characteristics, population data, and maps of the base year (2022). The models had high accuracy values of 0.999873850524 and 0.999999999903 with low error values of 0.058 and 0.0000000419 for trip production and attraction respectively. The models were then used to foresee trip production and attraction for the horizon year (2032).
congestion, transportation planning, travel demand, mathematical model, Artificial Neural Network, GIS, trip generation
ADAPTIVE OVERCURRENT DISTRIBUTION PROTECTION SCHEME COORDINATION IN THE PRESENCE OF DISTRIBUTED GENERATION USING ARTIFICIAL NEURAL NETWORK
Recent advances in the development of distributed generation (DG) technology have resulted in increased DG penetration into distribution networks. The comparative cost advantage of its installation over grid expansion far outweighs its disadvantages. However, DG penetration introduces a lot of protection issues as a result of variation in the network short circuit current and bidirectional flow of current that, if not properly coordinated, causes maloperation of overcurrent relay protection scheme. This paper presents a novel adaptive protection scheme coordination system that uses artificial neural network (ANN) to coordinate the operations of the main and the backup relays. The proposed method determines the time settings multipliers (TMS) and the plug settings multipliers (PSM) based on the network's prevailing condition and communicates the new settings to microprocessor-based relays via optic fiber by using remote terminal unit to update the settings. The proposed scheme was applied to the IEEE 33-bus distribution network considering two different scenarios: with and without DG penetration. NEPLAN software was used to generate different fault currents required for the ANN training. Obtained simulation results show that the proposed adaptive protection scheme coordination significantly improves the protection scheme coordination with or without DG penetration.
overcurrent relay, adaptive protection, protection coordination, distributed generation, artificial neural network
COMPARATIVE ANALYSIS OF THE PERFORMANCE OF 3G NETWORKS VOICE SERVICE IN IBADAN METROPOLIS
This paper aims to offer a comparative analysis of the main Nigerian mobile network service provider with reference to 3G voice service. Drive tests were engaged in Ibadan metropolis to acquire some KPI parameters used for the analysis. The findings show that not a single service provider was in good standing across all the KPIs. Thus, the performance of a particular operator is purely a function of the desired KPI parameter.
CONCEPT OF TRANSDUCER BASE FOR HUMS OF SUSPENSION SYSTEM OF HIGH MOBILITY WHEELED VEHICLE
The paper introduces the concept of a transducer base for HUMS of the suspension system of a high mobility wheeled vehicle. The basic principles of the maintenance system with HUMS as a subsystem and its structure are clarified. The main benefits for operators of the maintenance system after implementation of HUMS into vehicles are presented. Preliminary ranges of loads to be monitored, generated in a selected point in the suspension system of a vehicle with a GVW of 3.5T class are presented, as well as general dimensions and material selection for the base of the transducer.
high mobility wheeled vehicle, durability, suspension, transducer, CBM, HUMS, maintenance system
MANUFACTURING AND TESTING HIGH VOLTAGE FILTER CAPACITORS
This paper presents the manufacturing and testing methods of 30kV and 33nF high voltage filter capacitors. One of the biggest advantages of small companies is that they are able to produce a high diversity of capacitors in small quantities. One of the prices of this flexibility is a higher level of manual manufacturing process in production. But this higher level of manual manufacturing does not mean lower quality in the final product. For high quality products in the high voltage industry, it is necessary to do routine tests in all of the products. For high voltage capacitors the following three tests must be done to ensure quality: voltage strength test, partial discharge test, capacitance and dissipation factor test. The capacitance and dissipation factor test have to be done at different voltage levels. The voltage strength test has to be done at least 20% higher than the rated voltage. This kind of test gives us information not only about the quality of the product itself, but about distribution of the capacitance for example, or about the strength of the production process, and about the quality management system of the company.
high voltage filter capacitors, partial discharge, voltage strength, capacitance, dissipation factor
INTEGRATING NEURAL NETWORKS INTO SHEET METAL FORMING: A REVIEW OF RECENT ADVANCES AND APPLICATIONS
In order to predict defects, improve performance, and streamline operations, machine learning techniques are becoming ever more indispensable in manufacturing processes, mainly in sheet metal forming. Incorporating neural networks into the process of sheet metal forming is the subject of this article's exhaustive examination of recent developments and applications. Exploring datasets from a variety of sheet metal forming processes, numerous machine learning models, including ensemble and single learning techniques are investigated. The functionality of this method extends to various tasks, including the prediction of springback in cold-rolled anisotropic steel sheets. The review provides a conclusion section that presents the main implementation methodologies and how they address to some manufacturing issues.
neural network, sheet metal forming, springback compensation
A REVIEW OF THE RECENT RESEARCH ACTIVITIES IN THE FILD OF ELECTRICAL DISCHARGE MACHINING
Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes being considered one of the most popular machining methods today. The EDM process basis on thermoelectric energy between the workpiece and an electrode, so that the discharge energy generated during the operation characterizes the productivity of the process. Due to the well-established machining options utilized in the industry of aerospace, automotive industry and surgical components for precision machining and making complex geometrical shapes in hard-to-cut materials, a significant amount of research interests has been created in this field. This paper provides a review of numerous academic research activities carried out in the previous years, as well as numerous developments in the field of EDM related to increased machining rates, improved performance, materials and dielectrics used, electrode design and manufacture.
electrical discharge machining, electrode, dielectric, machining rates
INVESTIGATION OF THE EFFECTS OF THE ADDITION OF TITANIUM DIOXIDE (TiO2) NANOPARTICLE FUEL ADDITIVE IN COTTON BIODIESEL ON ENGINE PERFORMANCE
The importance of renewable fuels as an alternative to fossil fuels is increasing due to environmental problems such as the decrease in the reserves of fossil fuels, their presence in certain regions, air pollution and global warming. Two important parameters of biodiesel fuel, which is one of these fuel types, such as high viscosity and density, negatively affect its use. One of the ways to overcome this negative situation is to improve the fuel properties by adding nano fuel additives into biodiesel. In this study, titanium dioxide nano fuel additive was added to biodiesel obtained from cottonseed oil at the rates of 50 ppm and 75 ppm. Specific fuel consumption, brake thermal efficiency and cylinder pressure values, which are the basic performance parameters of the fuel mixtures, were determined in a single cylinder engine at 1800 rpm at 4 different engine loads. According to C100 fuel SFC decreased by 5.03% and 6.29% at 10 Nm load, respectively in CTi-50 and CTi-75 fuels. This improvement rate was 8.73% and 12.58% at 40 Nm load. BTE increased by 8.97% and 13.17% with NPs additives. Thanks to the thermophysical properties of the titanium dioxide fuel additive, the combustion reaction has improved and cylinder pressure increased. It was determined in the study that it positively affected the engine performance and fuel economy.
combustion, biodiesel, titanium dioxide (TiO2), NPs, engine performance
PREEMPTIVE AND NON-PREEMPTIVE GOAL PROGRAMMING APPROACH TO INVENTORY OPTIMIZATION OF THE CENTRAL STERILE SUPPLY DEPARTMENT, UNIVERSITY COLLEGE HOSPITAL, IBADAN, NIGERIA
This research applied a multi-criteria optimization technique to analyse the inventory system of a Central Sterile Supply Department (CSSD) through preemptive and non-preemptive goal programming. Data on six raw materials and four finished products were collected, in addition to their costs, demand rates, shelf lives, and available capital. The developed objective function of the non-preemptive model combined four goals: inventory cost optimization (highest priority), inventory turnover, service level, and delivery lead time. The implemented model guaranteed zero stock-outs, reduced wait times between productions, timely product sales, and the elimination of unnecessary overall costs.
goal programming, inventory system, multi-criteria optimization, optimum, sterile
STUDYING HOW DIESEL ENGINE ADDITIVES USING SILVER OXIDE (Ag2O) NANOPARTICLES AFFECT THE ENVIRONMENT
Abstract: Biodiesel has been defined as an alternative fuel that has the potential to be used instead of diesel fuel for years. In case of complete combustion reaction in engines, the products released do not directly threaten human health. Compared to diesel fuel, biodiesel has worse combustion performance due to some fuel properties. Therefore, incomplete combustion products such as hydrocarbon (HC), carbon monoxide (CO), nitrogen oxide (NOx), smoke emission and complete combustion products such as CO2 are thrown into the atmosphere. In this study, the changes in exhaust emissions of 50 ppm and 75 ppm Ag2O NPs were experimentally examined to improve the adverse combustion performance and emission characteristics of cottonseed oil methyl ester. In experiments, nano additive improved the thermal conductivity, mass dissipation and heat transfer of the test fuels, and resulted in reducing of CO emissions as it provided a higher oxidation rate of hydrocarbon molecules. Due to the improvement in the combustion reaction, CO2 emission increased with product of complete combustion. The increase in CO2 emissions was 3.17% and 3.97% for CAg-50 and CAg-75 fuels, respectively, when compared to C0 fuel at 40 Nm load. The NPs additive increased the lower calorific value of the fuel and cylinder temperature. This situation caused increase of NOx emissions by 3.69% and 7.47% CAg-50 and CAg-75 fuels 40 Nm load. Adding of NPs in base fuel reduced to viscosity and density provided better atomization. So a reduction in smoke emission was obtained with NPs addition by 35.09% and 47.32% in CAg-50 and CAg-75 fuels, respectively, compared to C0 fuel at 10 Nm load, while 7.45% and 19.43% at 40 Nm load.
exhaust emission, biodiesel, diesel engine, silver oxide (Ag2O), nanoparticles
RESEARCH ON THE RECOVERY OF SOME AGRICULTURAL WASTE FOR THE MANUFACTURE OF COMPOSITE MATERIALS WITH CLAY MATRICES
The article describes the results of the research carried out for the systemic description of the manufacturing technological processes of composite materials with clay matrix and insert from agricultural waste. The objectives of these researches include the valorization of agricultural waste and cheap and abundant resources to obtain composite materials usable in civil constructions or various rural developments, with properties superior to existing ones, for example adobe or clay bricks. The article describes the materials used, the technology of obtaining, the dependence between the output parameters and the input and control parameters.
agricultural waste, composites, clay, technology