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The present study is aimed to analyse the relationships of human responses to sudden changes in visual or hearing stimulations with respect to the age. As the accuracy of measurement of the time interval is significant in the study of human response, a microcontroller-based time measurement system is designed and developed with a resolution of 1 µs. The hardware of the device takes care of the generation and management of the clock through I/O ports of the microcontroller, while software captures and computes the response time. The effect of age on human responses to both visual and hearing stimuli was studied, and the natures of both the responses were compared. The results were analysed to determine the characteristics of human responses and the relationship between human response, type of stimulus, and age. It was shown that the human visual and hearing response-times increase with age, and the hearing response is faster than visual response. [ABSTRACT FROM AUTHOR]

This article presents the details of design and development of a mobile and low-cost measuring device that can directly measure the thermal conductivity of a material. The device does not need an AC power source and needs only a battery to operate. In its operation, the output of a platinum resistance thermometer (PT100 sensor) is amplified by LM324 Quad differential input operational amplifier and fed to Microchip PIC16F877A microcontroller through an analog-to-digital converter. The microcontroller calculates the thermal conductivity of the material by a given set of temperature difference and finally the result is displayed on a liquid crystal display. PIC Basic programming language is used to program the PIC microcontroller. The analog circuit and printed circuit board layout are designed using OrCAD software. It has been observed that the proposed device can measure the temperature with an accuracy of 0.5°C and thermal conductivity with an accuracy of 0.01 W/mm °C. The power consumption of the device is found to be 277.25 mW. [ABSTRACT FROM AUTHOR]

As part of the ongoing research on micro air vehicles, the present work focuses on the effect of membrane flexibility on the aerodynamic performance of flexible latex flapping wings. Wings with membrane thicknesses 0.37, 0.28, and 0.13 mm are chosen, which are named as least flexible (A), flexible (B), and most flexible (C), respectively. The experiments are performed in an air chamber of size 1.5 m × 1.5 m × 1.5 m, facilitated with wind velocities up to 15 m/s. The time-averaged lift and drag as functions of flapping frequency, forward flight velocity, the angles of attack (AoA), and advance ratio ( J). The novel electronic control system developed previously is used to monitor and measure the flapping frequency. It is found that the effect of flexibility on the aerodynamic performance mainly depends on the range of flight speed; at 7200 ≤ Re ≤ 18,000, the lift and drag increase with increase of flexibility, and at 18,000 ≤ Re ≤ 25,200, the lift decreases and drag increases with increase of flexibility. Hence latex compliant (Wing C) wings are advantageous in the low Re range, while the least flexible wing (Wing A) is preferable for higher range. [ABSTRACT FROM AUTHOR]