Assessment of household energy utilized for cooking in Ikeja, Lagos state, Nigeria

Changing parameters of the Korakianitis and Shi heart valve model over a cardiac cycle has led to the investigation of appropriate numerical technique(s) for good speed and accuracy. Two sets of parameters were selected for the numerical test. For the seven MATLAB ODE solvers, the computed results, computational cost and execution time were observed for varied error tolerance and initial time steps. The results were evaluated with descriptive statistics; the Pearson correlation and ANOVA at The dependence of the computed result, accuracy of the method, computational cost and execution time of all the solvers, on relative tolerance and initial time steps were ascertained. Our findings provide important information that can be useful for selecting a MATLAB ODE solver suitable for differential equation with time varying parameters and changing stiffness properties.

Performance Modelling of Steam Turbine Performance using Fuzzy Logic Membership Functions

Due to their potential applications in different areas of engineering, research into the development of improved Magnetorheological fluids (MRF) has increased. Developing novel MRF requires the use of magneto-rheometers which have a special ability to induce a magnetic field. Since the number of magneto-rheometers available limits MRF research, there is a need to develop a device that can be used to induce a magnetic effect on MRF, allowing the use of conventional rheometers for characterizing MRFs. This work is aimed at developing an electromagnet suitable for inducing a preset magnetic field on MRFs for rheological assessments. The electromagnet design incorporates a solenoid and a solenoid driver for controlling the generation of magnetic field intensity. The solenoid driver is designed by constructing a linear electric circuit capable of producing a maximum current of 3A and 12V DVC. The solenoid generates a magnetic field which can be varied by varying the current (0-3A) on the solenoid driver with the aid of a potentiometer since current [I] and magnetic field intensity [B] are directly proportional. An ammeter-voltmeter was integrated into the electromagnet system to display the amount of current and voltage flowing to the solenoid. The electro-magnetism of the device was modelled for possible scaling up as suitable. The theoretical, experimental, and simulated results show a strong correlation, and experiments proved that the electromagnet is useful to alter and test the dynamic characteristics of MR fluids.