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Start Over Descriptor "Radio-frequency" Language spanish; castilian
3 results on '"Radio-frequency"'

1. Microwave Models for Graphene Ambipolar Devices: an Engineering Teaching Perspective

Author

Francisco Pasadas, Alberto Medina-Rull, and Enrique G. Marín

Subjects
Phase shifter, Ambipolar, Computer Networks and Communications, Radiofrecuencia, Ingeniería, Computer Science Applications, Mezclador, Engineering, Multiplicador, Radio-frequency, Grafeno, Power amplifier, Graphene, Mixer, Amplificador de potencia, Desfasador, Multiplier, Information Systems
Abstract

In this article it iimplemented a set of circuit models to be exploited in conventional circuit simulators used in engineering degrees. The models capture the physics of the graphene-based transistors, characterized by the ambipolar conduction, and its resulting V-shaped transfer characteristics (current vs. gate voltage). These models can be exploited by the engineering students to explore ambipolar electronics opening the possibility to 1) redesigning and simplifying of conventional circuits; and 2)seeking of new functionalities in both analogue/RF and digital domains. In thisregard, as an example by just considering that the V-shaped transfer characteristicsbehaves as a parabola, we present new insights for the design of graphene-based RFpower amplifiers, mixers, phase shifters and frequency multipliers that specifically, En este trabajo, se implementan un conjunto de modelos que resuelven la física de los transistores basados en grafeno, capturando la conducción ambipolar y proporcionando las peculiares curvas de corriente frente a voltaje de puerta con forma de “V”. Estas herramientas pueden ser potencialmente utilizadas por estudiantes de ingeniería para explorar la electrónica ambipolar, abriendo la posibilidad de 1) rediseñar y simplificar aplicaciones de microondas convencionales; y 2) buscar nuevas funcionalidades en el ámbito analógico y de alta frecuencia. A este respecto, como ejemplo, presentamos nuevos enfoques para el diseño de multiplicadores de frecuencia, amplificadores de potencia, mezcladores y desfasadores en radiofrecuencia que específicamente aprovechan la ambipolaridad, PAIDI 2020 y de European Social Fund Operational Programme 2014–2020 no. 20804, Contrato PTA, con referencia PTA2020-018250-I

Published
2022

2. INDUSTRIAL EVALUATION OF RE-DRY STRATEGY FOR SOFTWOOD LUMBER

Author

Diego Elustondo and Stavros Avramidis

Subjects
lumber, drying, re-drying, radio-frequency, modeling, Forestry, SD1-669.5, Manufactures, TS1-2301
Abstract

This paper presents an experimental evaluation of the first commercial scale dry-sort-redry (DSRD) strategy for drying of 2x4 Pacific coast hemlock (PCH) lumber. The DSRD strategy is a methodology designed to reduce final moisture content variability in kiln dried lumber by complementing conventional drying with radio frequency vacuum (RFV) drying technology. The strategy′s objective is to avoid producing over-dried lumber in conventional drying by setting the target moisture content to a value much higher than those usually used in industry. Then, RFV drying technology is implemented to quickly and efficiently re-dry the lumber that remains wet (under-dried) after the first conventional pass. Six experimental tests were performed in an industrial sawmill with the intention of studying the effect of target moisture content on the properties and quality of the dried lumber. In all cases, the first drying pass was performed in a 260m³ industrial heat-and-vent conventional kiln, and the re-drying of wets was performed in a 75m³ RFV kiln. Additionally, a mathematical model developed for prediction of data dispersion in lumber drying was calibrated with experimental data, and used to simulate the DSRD strategy under other hypothetical conditions. The results of the study demonstrate that the DSRD strategy reduces drying time, shrinkage and kiln drying degrade in comparison with a single conventional pass

Published
2005

3. Industrial evaluation of re-dry strategy for softwood lumber

Author

Diego Elustondo, Stavros Avramidis, and Luiz Oliveira

Subjects
lumber, drying, re-drying, radio-frequency, modeling, Forestry, SD1-669.5, Manufactures, TS1-2301
Abstract

This paper presents an experimental evaluation of the first commercial scale dry-sort-redry (DSRD) strategy for drying of 2x4 Pacific coast hemlock (PCH) lumber. The DSRD strategy is a methodology designed to reduce final moisture content variability in kiln dried lumber by complementing conventional drying with radio frequency vacuum (RFV) drying technology. The strategy’s objective is to avoid producing over-dried lumber in conventional drying by setting the target moisture content to a value much higher than those usually used in industry. Then, RFV drying technology is implemented to quickly and efficiently re-dry the lumber that remains wet (under-dried) after the first conventional pass. Six experimental tests were performed in an industrial sawmill with the intention of studying the effect of target moisture content on the properties and quality of the dried lumber. In all cases, the first drying pass was performed in a 260m3 industrial heat-and-vent conventional kiln, and the re-drying of wets was performed in a 75m3 RFV kiln. Additionally, a mathematical model developed for prediction of data dispersion in lumber drying was calibrated with experimental data, and used to simulate the DSRD strategy under other hypothetical conditions. The results of the study demonstrate that the DSRD strategy reduces drying time, shrinkage and kiln drying degrade in comparison with a single conventional pass.

Published
2014

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