Volume 30, No. 1 (2024)

STUDYING HOW DIESEL ENGINE ADDITIVES USING SILVER OXIDE (Ag2O) NANOPARTICLES AFFECT THE ENVIRONMENT

CIHAN BAYINDIRLI(*1), MEHMET CELIK(2)

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.

PREEMPTIVE AND NON-PREEMPTIVE GOAL PROGRAMMING APPROACH TO INVENTORY OPTIMIZATION OF THE CENTRAL STERILE SUPPLY DEPARTMENT, UNIVERSITY COLLEGE HOSPITAL, IBADAN, NIGERIA

MOJISOLA BOLARINWA(*), KHALID BELLO, PAUL ADEOSUN

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.

INVESTIGATION OF THE EFFECTS OF THE ADDITION OF TITANIUM DIOXIDE (TiO2) NANOPARTICLE FUEL ADDITIVE IN COTTON BIODIESEL ON ENGINE PERFORMANCE

MEHMET CELIK(1), CIHAN BAYINDIRLI(2*)

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.

A REVIEW OF THE RECENT RESEARCH ACTIVITIES IN THE FILD OF ELECTRICAL DISCHARGE MACHINING

OANA-GEORGETA GHIORGHE, CAROL SCHNAKOVSZKY(*), MARIA-CRINA RADU, CATALIN NICOLAE TAMPU, BOGDAN NITA

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.

INTEGRATING NEURAL NETWORKS INTO SHEET METAL FORMING: A REVIEW OF RECENT ADVANCES AND APPLICATIONS

COSMIN - CONSTANTIN GRIGORAȘ(*), ȘTEFAN COȘA, VALENTIN ZICHIL

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.

MANUFACTURING AND TESTING HIGH VOLTAGE FILTER CAPACITORS

ISTÓK RÓBERT(1), GÁL TIBOR(2), JASZTRAB PÉTER JÁNOS(1), PETRU GABRIEL PUIU(*3), SZÉN ISTVÁN(1)

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.

CONCEPT OF TRANSDUCER BASE FOR HUMS OF SUSPENSION SYSTEM OF HIGH MOBILITY WHEELED VEHICLE

KOSOBUDZKI MARIUSZ(*1)

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.

COMPARATIVE ANALYSIS OF THE PERFORMANCE OF 3G NETWORKS VOICE SERVICE IN IBADAN METROPOLIS

HAMMED OYEBAMIJI LASISI(1), IDOWU OLAMIDE HUSSEIN(*1), MUHAMMED BABAJUDE HAMMED(1), OLAJIDE MICHEAL ODOFIN(1)

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.