Unizik Journal of Technology, Production and Mechanical Systems

Effect of corrosion on the tensile strength of structural steel (UNS G10170) exposed to seawater

2022-06-13T13:24:08+01:00

Carbon steel is the most widely used engineering material and despite its relatively limited corrosion resistance, is used in large tonnages in marine applications, chemical processing, petroleum production and refining, pipelines, etc. The corrosion of carbon steels is a problem of enormous practical importance because the cost of metallic corrosion to the total economy of the world runs into hundreds of millions of dollars per year. This work was carried out to study the effect of corrosion on the mechanical properties of structural steel (UNS G10170) exposed to seawater. Steel samples were subjected to normalising heat treatment, before being immersed in seawater at 15 days intervals for duration of 90 days. The corrosion rates of the steel samples were determined by the weight loss method. The results showed a 9.00% decrease in hardness for the as received sample and 6.50% decrease for the normalised sample; 12.23% decrease in tensile strength for the as-received sample and 7.90% decrease for the normalised sample respectively at the end of the 90^th day. It was found that ferrite was less noble than cementite, which caused it to sacrificially dissolve once the samples were polarized in the sweater environment thereby leading to loss of material (weight loss) and consequently reduction in mechanical properties

Modelling of the drying characteristics of Gmelina arborea wood: kinetics and thermodynamics studies

2022-07-30T19:40:44+01:00

Abstract

A cost-effective design for read-only memory based digital system emulation

2023-02-22T08:21:51+01:00

A digital systems design approach using emulation technique and Read Only Memory (ROM) as a major component has been presented. Emulation as implied here, simply means using a logic device to mimic the behavior of one or more logic devices or a control system. To effectively mimic these logic devices, their characteristics drawn from their individual truth tables (or logic table) where programmed into the ROM using their input patterns as the address to the memory location where their output patterns are stored. With the connection of other peripheral devices such as input and output devices, display, select buttons etc., a ROM based digital systems design is developed. A specific design problem involving the development of a logic trainer was demonstrated. The trainer developed is portable, has simple logic section and is cost effective. The emulation technique used in this design is systematic and can be applied to develop other digital system designs.

Design and development of a laboratory scale hydraulic arm for engineering education

2023-02-25T07:04:54+01:00

Robotics are now completely necessary in contemporary industry. Its development and application in the manufacturing sector have enhanced output, improved product quality, and decreased the cost of high labor within these sectors with high labor costs. The design and construction of a hydraulic arm on a laboratory scale are included in this study. Here, a thorough and understandable description of what a robot is was given. The arm's 3D model was created using the soft AutoCAD tool during the design phase. Pascal's principle was also used to gauge the size of the forces causing the motion of the arm’s various linkages. A detailed explanation of how to determine the hydraulic arm's degree of freedom was provided

Design of a prototype digital water level controller using ultrasonic sensor interfaced microcontroller

2023-03-21T04:15:34+01:00

This work designed and fabricated a prototype digital water level controller using ultrasonic sensor interfaced with microcontroller. The supply and overhead tanks were designed and fabricated with fiber glass of thickness 5mm. The electric pump was selected based on the capacity of the overhead tanks and its distance from the supply source. Polyvinyl Chloride (PVC) pipes were selected based on its carbon content, low cost, chemical resistance and ease of joining. The electronic circuit was designed and built using ultrasonic sensor, microcontroller, transistors and relays. Result obtained on testing shows that the controller regulates the ON and OFF of the pump depending on the water levels in the overhead tank. At the highest discharge level of the electric pumping machine which was 900m, the efficiency of the sensor response was found to be 88.9%. This shows that a good result was on the prototype design

Evaluation of plastic pipes production quantities with some selected traditional forecasting techniques using historical data

2023-03-21T05:49:00+01:00

This work focused on the use of forecasting methods to model and analyzes the production of pipe products in Finoplastika manufacturing industry. The literature revealed that no study has ever being revealed and other literatures have not intensively express about its prediction and forecasting of their production quantity. The case company has no specific method of foreseen the future productivity of the production output in the case company. This serves as the knowledge gap which the researcher tends to revealed. Data on production yield were collected from the industry covering a period of three years. The forecasting models developed were used to forecast the outputs of the future production of the products type investigated. From the results of the evaluation of the forecasting accuracy measure, it can be deduced that the production output for product 1(P1) is 12910.1 units, production output for product 2 (P2) is 4882.3 units, production output for product 3 (P3) is 9877.3 units and the production output for product 4 (P4) is 11013.5 units. The results show that the model with the list error is the most appropriate method to achieve the best forecasting result. The study concludes that the forecasting models are appropriate and it has predicted the appropriate results for the future productivity. These methods were also applied for other products for monthly yield of the product types investigated.