Results 21 to 30 of about 60,609 (213)

Monitoring Accessibility Services in Digital Television

open access: yesInternational Journal of Digital Multimedia Broadcasting, Volume 2012, Issue 1, 2012., 2012
This paper addresses methodology and tools applied to the monitoring of accessibility services in digital television at a time when the principles of accessibility and design are being considered in all new audiovisual media communication services. The main objective of this research is to measure the quality and quantity of existing accessibility ...
Francisco Utray   +4 more
wiley   +1 more source

Metamateriales en microondas y antenas [PDF]

open access: yes, 2003
Desde la década de los '80 una gran variedad de materiales artificiales (no existentes en la naturaleza) son intensivamente estudiados por sus inusitadas y sorprendentes propiedades electromagnéticas (como partes reales de permitividad eléctrica y ...
González Arbesú, José María   +2 more
core   +3 more sources

Desenvolvimento de etiquetas RFID-UHF têxteis

open access: yesRevista Principia, 2020
Este artigo propõe o desenvolvimento de antenas têxteis para aplicações em sistemas de identificação por radiofrequência (RFID). O tecido jeans, comercialmente vendido, foi utilizado como substrato dielétrico, e como condutor, um tecido de poliéster com ...
Rudrigo Rangel Lima   +4 more
doaj   +1 more source

Análise experimental do efeito de diversas configurações de "inset feed" na alimentação de antenas planares dos tipos retangular, circular e triangular

open access: yesRevista Principia, 2014
Este artigo trata da análise experimental de antenas planares, com geometria do patch dos tipos retangular, circular e triangular, com alimentação por linha de microfita e técnica de casamento de impedância através de reentrâncias (inset feed ...
Jefferson Costa e Silva
doaj   +1 more source

Desarrollo de un sistema de nivelación de antenas HF en terrenos irregulares en Colombia

open access: yesPerspectivas en Inteligencia, 2023
Los campos de antenas utilizados en la banda de alta frecuencia (High Frecuency) son esenciales para la ejecución de operaciones de radiogoniometría y tácticas de Guerra Electrónica (Electronic War) en inteligencia de señales. Estos sistemas requieren en
Diana Patricia Gómez Vargas   +3 more
doaj   +1 more source

Revision of Manettia (Rubiaceae) in Paraguay

open access: yesNordic Journal of Botany, Volume 2026, Issue 2, February 2026.
Manettia Mutis is a Neotropical genus comprising over 100 species, many of which are only known from their original descriptions or, at most, from revisions dating back over 100 years. Recent review studies have remained unpublished for several years. Conventional taxonomic methods are followed.
Silvana Yasmin Gauto   +2 more
wiley   +1 more source

Software Radio para antenas inteligentes en comunicaciones personales multistandard [PDF]

open access: yes, 1998
Peer ReviewedPostprint (published ...
Cabrera-Bean, Margarita   +6 more
core  

Carbon Emissions From Low‐Order Streams in a Tropical, High‐Elevation, Peatland Ecosystem Are Mediated by Catchment Morphology

open access: yesWater Resources Research, Volume 61, Issue 4, April 2025.
Abstract Inland waters emit large amounts of carbon and are key players in the global carbon budget. Particularly high rates of carbon emissions have been reported in streams draining mountains, tropical regions, and peatlands. However, few studies have examined the spatial variability of CO2 concentrations and fluxes occurring within these systems ...
Keridwen M. Whitmore   +5 more
wiley   +1 more source

Beyond Income Disparities: Perceived Health and Education Inequities Drive Actions to Reduce Economic Inequality

open access: yesEuropean Journal of Social Psychology, Volume 55, Issue 2, Page 396-415, March 2025.
ABSTRACT Perceiving income disparities has a limited impact on attitudes towards reducing economic inequality. In this research, we proposed a novel and alternative strategy by focusing on other aspects intrinsically related to economic inequality, such as unequal access to health and education resources.
Francisco Miguel Soler‐Martínez   +2 more
wiley   +1 more source

Antenas multifrecuencia y multifunción basadas en tecnología impresa simple parcialmente rellenas con estructuras metamateriales [PDF]

open access: yes, 2008
El grupo de Radiofrecuencia de la Escuela Politécnica Superior de la Universidad Carlos III de Madrid lleva desarrollando desde hace muchos años antenas basadas en tecnología impresa.
Segovia Vargas, Daniel
core   +1 more source

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