Unmanned Aerial System-Based Data Ferrying over a Sensor Node Station Network in Maize

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/)

A systematic review of randomised controlled trials assessing effectiveness of prosthetic and orthotic interventions.

BACKGROUND: Assistive products are items which allow older people and people with disabilities to be able to live a healthy, productive and dignified life. It has been estimated that approximately 1.5% of the world's population need a prosthesis or orthosis. OBJECTIVE: The objective of this study was to systematically identify and review the evidence from randomized controlled trials assessing effectiveness and cost-effectiveness of prosthetic and orthotic interventions. METHODS: Literature searches, completed in September 2015, were carried out in fourteen databases between years 1995 and 2015. The search results were independently screened by two reviewers. For the purpose of this manuscript, only randomized controlled trials which examined interventions using orthotic or prosthetic devices were selected for data extraction and synthesis. RESULTS: A total of 342 randomised controlled trials were identified (319 English language and 23 non-English language). Only 4 of these randomised controlled trials examined prosthetic interventions and the rest examined orthotic interventions. These orthotic interventions were categorised based on the medical conditions/injuries of the participants. From these studies, this review focused on the medical condition/injuries with the highest number of randomised controlled trials (osteoarthritis, fracture, stroke, carpal tunnel syndrome, plantar fasciitis, anterior cruciate ligament, diabetic foot, rheumatoid and juvenile idiopathic arthritis, ankle sprain, cerebral palsy, lateral epicondylitis and low back pain). The included articles were assessed for risk of bias using the Cochrane Risk of Bias tool. Details of the clinical population examined, the type of orthotic/prosthetic intervention, the comparator/s and the outcome measures were extracted. Effect sizes and odds ratios were calculated for all outcome measures, where possible. CONCLUSIONS: At present, for prosthetic and orthotic interventions, the scientific literature does not provide sufficient high quality research to allow strong conclusions on their effectiveness and cost-effectiveness

Energy Efficient Supply Boosted Comparator Design

This paper presents a new mixed-signal design technique called supply boosting technique (SBT) and the design of an energy efficient, sub-1 V supply boosted comparator (SBC) in a standard complementary metal oxide semiconductor (CMOS) process. The selected CMOS process does not allow sub-1 V operation with a wide input range due to high threshold voltage (high-VTH) of MOS transistors (+0.8 V/−0.9 V). Despite this, the proposed comparator operates sub-1 V supply voltages with input common mode voltage larger than 60% of supply voltage by utilizing a supply boosting technique. The measured power consumption of the supply boosted comparator for 1 V supply was 90 nW and speed was 6500 conversions per second, resulting in 14 pJ per conversion energy efficiency

Improved oil recovery using alkaline solutions in limestone medium

In this study, the effect of sodium hydroxide (NaOH) and sodium silicate (NaSiO4) solutions for the improved oil recovery of Garzan (26 API degrees) and Raman (17.2 API degrees) crude oils with variable salinity of the alkaline solutions, and the effect of injection flow rate at the salinity values of the alkaline solutions that yielded maximum oil recovery for both crude oils has been investigated using a one-dimensional unconsolidated limestone reservoir model. As the previous study, the interfacial tension measurements of the given crude oils and alkaline solutions interface have been measured to find the optimum concentrations of the alkaline that give the minimum interfacial tension at the crude oil/alkaline solution interface, at different salinity of the alkaline solutions. Using these optimum alkaline concentrations, 22 displacement runs have been performed; 13 runs with the variable salinity of the alkaline solutions, six runs with the variable injection flow rate, and the remaining three runs were the base floods, performed without oil to see the interaction of alkaline solutions with the porous matrix. The results of the displacement tests showed that the NaOH solutions with increasing salinity, has given the most significant incremental oil recovery, about 3-9% for Garzan crude oil, while the NaOH and NaSiO4 solutions with different salinity did not produced any significant incremental oil recovery for Raman crude oil, when compared with the base waterfloods performed for each crude oil types. Six displacement runs have been performed; three runs for Garzan crude oil and three runs for Raman crude oil at injection flow rates of 400, 300, 200 and 100 cm(3)/h for each crude oil with the salinity of the alkaline solution that yielded maximum oil recovery. The results of the displacement tests showed that injection flow rate of alkaline solution has an important effect on Garzan crude oil and has less effect on Raman crude oil in the scope of oil recovery achieved. The optimum injection flow rates for both Garzan and Raman crude oils have been found, which was 200 cm3/h for Garzan crude oil and 300 cm3/h for Raman crude oil for our model

A Low-Power and Low-Voltage Power Management Strategy for On-Chip Micro Solar Cells

Fundamental characteristics of on-chip micro solar cell (MSC) structures were investigated in this study. Several MSC structures using different layers in three different CMOS processes were designed and fabricated. Effects of PN junction structure and process technology on solar cell performance were measured. Parameters for low-power and low-voltage implementation of power management strategy and boost converter based circuits utilizing fractional voltage maximum power point tracking (FVMPPT) algorithm were determined. The FVMPPT algorithm works based on the fraction between the maximum power point operation voltage and the open circuit voltage of the solar cell structure. This ratio is typically between 0.72 and 0.78 for commercially available poly crystalline silicon solar cells that produce several watts of power under typical daylight illumination. Measurements showed that the fractional voltage ratio is much higher and fairly constant between 0.82 and 0.85 for on-chip mono crystalline silicon micro solar cell structures that produce micro watts of power. Mono crystalline silicon solar cell structures were observed to result in better power fill factor (PFF) that is higher than 74% indicating a higher energy harvesting efficiency