scholarly journals A Simple WiFi Harvester with a Switching-Based Power Management Scheme to Collect Energy from Ordinary Routers

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1191
Author(s):  
Fernando Angulo ◽  
Loraine Navarro ◽  
Christian G. Quintero Quintero M. ◽  
Mauricio Pardo

This paper shows the design process of a simplified harvesting circuit for WiFi at the 2.4 GHz frequency band based on the analysis of the environment available signals. Those signals and their power level define an antenna design to maximize captured energy and select the proper number of stages for a voltage multiplier so that an impedance matching network is no longer required. With this, it is possible to maintain the harvester architecture simple without sacrificing performance. The use of supercapacitors is preferred over batteries due to their high-power capacity, the ability to deliver high peak currents, long-life cycle size, and low cost. Hence, supercapacitor availability allows to devise a novel switching scheme that employs two units that favor energy use and speed up the recharging process. The built harvester exhibits a power conversion efficiency greater than 50% under an incident signal of 0 dBm in the rectenna. The tests are carried out in an academic environment using a multi SSID router, collecting 494 mJ without requiring special modifications in the router used as an energy source.

2021 ◽  
Author(s):  
Yazan Al-Alem ◽  
Syed M. Sifat ◽  
Yahia M. M. Antar ◽  
Ahmed A. Kishk
Keyword(s):  
Low Cost ◽  

2018 ◽  
Vol 69 (12) ◽  
pp. 1237 ◽  
Author(s):  
G. C. Wright ◽  
M. G. Borgognone ◽  
D. J. O Connor ◽  
R. C. N. Rachaputi ◽  
R. J. Henry ◽  
...  

Breeding for improved blanchability—the propensity of the testa (skin) to be removed from the kernel following rapid heat treatment—is a priority for improvement in the Australian Peanut Breeding Program (APBP). Easy removal of the testa by blanching is required for processing of peanuts into peanut butter and various other confectionary products. Thus, blanchability is an economically important trait in any newly released cultivar in Australia. A better understanding of the range of genetic variation, nature of inheritance and genotype×environment (G×E) interactions, and the development of a low-cost method to phenotype in early generations, could speed up breeding for this trait. Studies were conducted to develop a low-cost, rapid method utilising minimal amounts of seed to phenotype in early generations, along with an assessment of G×E interactions over a range of years and environments to derive optimal selection protocols. Use of a smaller kernel sample size than standard (50 vs 200g) was effective for accurately assessing blanchability in breeding lines and could allow selection in early generations (e.g. in seed produced from a single F2 plant where seed supply is adequate). G×E interaction for blanchability was shown to be very low. Genotypic variance explained 62–100% of the total variance for blanchability, assessed in two diverse germplasm pools including 107 accessions in the USA mini-core over three environments and multiple APBP breeding lines grown over nine different years–environments. Genotypic correlations between all environments were very high (~0.60–0.96), with heritability for the blanchability trait estimated to be very high (0.74–0.97) across the 13 trials. The results clearly demonstrate that effective selection for improved blanchability can be conducted in early generations and in a limited number of contrasting environments to ensure consistency of results.


2017 ◽  
Vol 9 (10) ◽  
pp. 253
Author(s):  
Luciano Fernandes Moura ◽  
Pedro Felipe Sousa Teixeira ◽  
Franklin Aragão Gondim ◽  
Francisco Holanda Nunes Junior ◽  
Rifandreo Monteiro Barbosa ◽  
...  

Biodigesters have been used to convert biomass into biogas and biofertilizers. This energy use has been important for the reduction of solid waste pollution in the environment. This work aims to analyse the viability of the use of pig biofertilizer produced by an Indian biodigester prototype, monitored by a data acquisition system. The biodigester used was an Indian prototype built on a low cost material that is easy to acquire (polyvinyl chloride-PVC). After the biofertilizer production, we tested its efficiency and viability under conditions of vegetation house in the cultivation of sunflower plants. The experimental design was completely randomized in a factorial arrangement with 4 concentrations of biofertilizer (0, 40, 80 and 120 kg N ha-1) × 4 harvest periods (14, 21, 25 and 29 days after sowing). We evaluated biometric and vigor parameters by measurements of stem diameter, height of the aerial part, number of leaves and production of fresh and dry matter of roots, aerial and total parts, as well as the relative chlorophyll content. We performed the experiment with five repetitions using two plants each and we submitted the data to analysis of variance (ANOVA) and polynomial regression using the statistical software Sisvar 5.4. The functional Indian biodigester prototype produced a biofertilizer of excellent quality and viability as a biofertilizer for the initial growth of sunflower plants. The biofertilizer served as a nutritional source in the sunflower crop, since it provided increases in all the growth parameters analyzed in relation to the control group (plants in the absence of biofertilizer), especially in the concentration of 120 kg N ha-1.


2012 ◽  
Vol 81 ◽  
pp. 65-74 ◽  
Author(s):  
Jacopo Iannacci ◽  
Giuseppe Resta ◽  
Paola Farinelli ◽  
Roberto Sorrentino

MEMS (MicroElectroMechanical-Systems) technology applied to the field of Radio Frequency systems (i.e. RF-MEMS) has emerged in the last 10-15 years as a valuable and viable solution to manufacture low-cost and very high-performance passive components, like variable capacitors, inductors and micro-relays, as well as complex networks, like tunable filters, reconfigurable impedance matching networks and phase shifters, and so on. The availability of such components and their integration within RF systems (e.g. radio transceivers, radars, satellites, etc.) enables boosting the characteristics and performance of telecommunication systems, addressing for instance a significant increase of their reconfigurability. The benefits resulting from the employment of RF-MEMS technology are paramount, being some of them the reduction of hardware redundancy and power consumption, along with the operability of the same RF system according to multiple standards. After framing more in detail the whole context of RF MEMS technology, this paper will provide a brief introduction on a typical RF-MEMS technology platform. Subsequently, some relevant examples of lumped RF MEMS passive elements and complex reconfigurable networks will be reported along with their measured RF performance and characteristics.


Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1467 ◽  
Author(s):  
José Ignacio Arranz ◽  
María Teresa Miranda ◽  
Francisco José Sepúlveda ◽  
Irene Montero ◽  
Carmen Victoria Rojas

Brewing industry generates a main residue, brewers’ spent grain (BSG), which has good properties both for use in animal consumption and for thermal use, but contains a very high content of moisture (20–25% dry matter content), so that its elimination or treatment should be immediate, since it can cause degeneration problems of the product. Currently, brewers often supply this material at low cost for use as livestock feed. This solution is not efficiently carried out without reporting too much benefit to the brewers more than to eliminate waste from their facilities. However, BSG is a raw material of interest for application in different areas due to its low price, availability throughout the year and a valuable chemical composition, so it seems necessary to look for an alternative use to give value to these characteristics. In this paper a drying study is carried out in order to establish the foundations for its energy use by thermal of BSG. BSG has been used from a craft brewery located at Badajoz, Spain. Drying analysis was carried out for various temperatures and inlet air flow by means a convective dryer. The properties studied show that BSG can be used for thermal utilization in large installations, being necessary heat drying processes as a pretreatment in order to obtain a biofuel with acceptable efficiency.


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