Sarwar Hossen

This paper discerns key ideas and themes of a two dimensional prototype tower crane designed to pick up a metallic object and place that in a prefixed location with a befitting electromagnet manipulated by a robust microcontroller. The proposed crane is powered by two stepper motors one for vertical movement and another for horizontal movement where both steppers are controlled with a powerful and programmable microcontroller. Both The vertical scale up and scale down are programmable with 3600 freedom of horizontal rotation. Stepper motor provides with precise control over the crane and high holding torque. Microcontroller reduces the complex circuitry and provides with robust flexibility to change vertical elevation and angle of rotation. An AC Electromagnet with necessary shielding is used to pick targeted thing. The proposed designed has practically constructed with one NEMA8 and One NEMA 11 stepper motors that work fine with holding torque 4 oz-inch. This prototype version is t...

Abstract This work proposes a modeling of self-assembled monolayers (SAMs) to assess the quality of SAM layers in terms of their leaky behavior. In the modeling, electrochemical impedance spectroscopy (EIS) and a conceptual and simplified resistance-resistance-capacitance (RRC) electrical model from an electrochemical setup were demonstrated. Based on the model, Matlab-based simulation was carried out to find out the suggestive low frequency measurement for analyzing the defective monolayers. Finally, the developed electrical model facilitated the interpretation of the EIS spectra measured in the range of 10 Hz to 100 kHz and provided the capacitance, resistance and thickness of the monolayer. Thus the proposed model could be considered as a powerful tool to characterize the defective SAMs, which was very specific to determine the resistive behavior of the self-assembled monolayers prepared for shorter adsorption time.