Too many shades of grey : photometrically and spectrally mismatched targets and backgrounds in printed acuity tests for infants and young children

Purpose: Acuity tests for infants and young children use preferential looking methods that require a perceptual match of brightness and color between grey background and target spatial average. As a first step in exploring this matching, this article measures photometric and colorimetric matches in these acuity tests. Methods: The luminance, uniformity, contrast, and color spectra of Teller Acuity Cards, Keeler Acuity Cards for Infants, and Lea Paddles under ambient, warm, and cold lighting, and of grey-emulating patterns on four digital displays, were measured. Five normal adults’ acuities were tested at 10 m observationally. Results: Luminance and spectral mismatches between target and background were found for the printed tests (Weber contrasts of 0.3% [Teller Acuity Cards], −1.7% [Keeler Acuity Cards for Infants], and −26% [Lea Paddles]). Lighting condition had little effect on contrast, and all printed tests and digital displays met established adult test luminance and uniformity standards. Digital display grey backgrounds had very similar luminance and color whether generated by a checkerboard, vertical grating, or horizontal grating. Improbably good psychophysical acuities (better than −0.300 logMAR: (logarithm of the minimum angle of resolution)) were recorded from adults using the printed tests at 10 m, but not using the digital test Peekaboo Vision. Conclusions: Perceptible contrast between target and background could lead to an incorrectly measured, excessively good acuity. It is not clear whether the luminance and spectral contrasts described here have clinically meaningful consequences for the target patient group, but they may be avoidable using digital tests. Translational Relevance: Current clinical infant acuity tests present photometric mismatches that may return inaccurate testing results

Urbanization and prevalence of type 2 diabetes in Southern Asia:A systematic analysis

Diabetes mellitus is one of the diseases considered to be the main constituents of the global non–communicable disease (NCD) pandemic. Despite the large impact that NCDs are predicted to have, particularly in developing countries, estimates of disease burden are sparse and inconsistent. This systematic review transparently estimates prevalence of type 2 diabetes mellitus in Southern Asia, its association with urbanization and provides insight into the policy challenges facing the region

Design and Development of a Smart Vortex Turbine

The growing demand for clean energy has led many engineers and scientists to find a way to effectively generate and distribute electricity without any carbon footprints. One of the most prominent and widely known methods of generating electricity is Hydropower. One of the leading researches in harvesting energy from low-head water sources is through a gravitational vortex turbine. Gravitational vortex turbine is special type of micro-hydro turbine that relies on the rotational energy of a water vortex. This research delves into techniques required to increase the efficiency of vortex turbines. This project bolsters an extensive design methodology used to finalize a system of smart vortex turbine. It includes a section on CAD modelling and governing equations followed by an ANSYS simulation to predict and study the vortex generated in main tank. The main goal of this project is to achieve a water tight sealing to ensure that generator does not gets damaged. In addition, reducing mechanical losses due to vibrations by using a smaller shaft is one of the set targets of this project. Our mission is prove that electricity can be generated in off the grid communities with low-head water sources by using 3D printing as Pakistan does not have the modern expensive fabrication techniques to manufacture complex geometries. There is a need to look for a cost effective, efficient and green manufacturing method

Microcontroller-based Sonar Ultrasonic Water Level Control System with Closed-loop Control Approach

This study proposes a microcontroller-based closed-loop water level control system that utilizes a sonar ultrasonic sensor to monitor and regulate water levels in a tank. The system operates by continuously checking the water level in the tank and adjusting the valve’s opening and closure times to maintain the desired water level. The closed-loop control approach employed by the system offers a precise water level control solution that can significantly reduce water waste in water pumping systems. The paper also assesses the theoretical and experimental response of an open-loop water level control system. The findings demonstrate that the closed-loop system outperforms the open-loop system, indicating the effectiveness of the proposed approach in maintaining water levels in a tank. The proposed system is not only applicable to water pumping systems but can also be used to manage the flow of hot and cold water from home water heaters. Additionally, the system can be utilized in various industries that require level or flow control, with particular emphasis on the production of distilled water, juice, and milk