Radio Frequency Energy Harvesting - Sources and Techniques

Energy harvesting technology is attracting huge attention and holds a promising future for generating electrical power. This process offers various environmentally friendly alternative energy sources. Especially, radio frequency (RF) energy has interesting key attributes that make it very attractive for low-power consumer electronics and wireless sensor networks (WSNs). Ambient RF energy could be provided by commercial RF broadcasting stations such as TV, GSM, Wi-Fi, or radar. In this study, particular attention is given to radio frequency energy harvesting (RFEH) as a green technology, which is very suitable for overcoming problems related to wireless sensor nodes located in harsh environments or inaccessible places. The aim of this paper is to review the progress achievements, the current approaches, and the future directions in the field of RF harvesting energy. Therefore, our aim is to provide RF energy harvesting techniques that open the possibility to power directly electronics or recharge secondary batteries. As a result, this overview is expected to lead to relevant techniques for developing an efficient RF energy harvesting system

Maximum photosynthetic assimilation in quinoa varieties (Chenopodium quinoa) from different geographic origins, and its relation to leaf morphology

Este trabajo brinda datos sobre las diferentes respuestas fisiológicas y morfológicas de seis variedades de Chenopodium quinoa Willd, de diferentes orígenes geográ- ficos, cultivadas bajo las mismas condiciones ambientales. Se analizaron el intercambio de gases (asimilación fotosintética máxima, Amax; conductancia estomática, gs, transpiración, Tr, concentración interna de CO2, Ci y eficiencia intrínseca en el uso del agua EUAi, anatomía foliar (densidad estomática, DE, tamaño estomático, TE, espesor de los tejidos, ET), área foliar específica, AFE y contenido de pigmentos fotosintéticos y protectores. Las experiencias se realizaron en una región árida del Noroeste Argentino (Amaicha del Valle, 22º31’S, 65º 59’ W, 1.985 m) bajo condiciones de sequía. Las variedades utilizadas fueron: Kancolla (Perú) y Sayaña (Altiplano Boliviano, 3.850 m), Quinoa Blanca (Cochabamba, Bolivia, 2.570 m), Quinoa Roja (Cangrejillos, Argentina, 3.700 m), CICA (originalmente obtenida en Perú pero ahora cultivada en Argentina a 2.000 m) y CO-407, una variedad de Chile, de zonas bajas (140 m). En general, los datos muestran que gs es una variable importante en el control de Amax pero la magnitud de este control depende de la variedad considerada. El valor más alto de Amax fue registrado para la variedad CICA (31 µmol m-2 s-1) y el más bajo para la variedad CO-407 con 19 µmol m-2 s-1. En relación a la capacidad de carboxilación y EUAi, los datos obtenidos permiten inferir que las variedades de altura (Sayaña y Kancolla) poseen valores altos de EUAi y capacidad de carboxilación en relación a las variedades provenientes de media y baja altitud (CO-407 y CICA). El valor de AFE no mostró variaciones de significación entre las variedades estudiadas. Todas resultaron ser anfiestomáticas con DE mayor en la epidermis inferior. Se encontró una correlación lineal positiva entre Amax y DE. Los resultados obtenidos aportan datos de valor biológico que pueden ser utilizados para los estudios relacionados al mejoramiento y/o selección varietal en ambientes de media y alta montaña. Palabras clave: Fotosíntesis, quinoa, tejidos foliares.Leaf gas exchange (Maxima photosynthetic assimilation, Amax; stomatal conductance, gs; leaf transpiration, Tr; internal CO2, and Ci concentration, and anatomical leaf data (stomatal density and size, tissue thickness), specific leaf area (SLA), photosynthetic and protection pigments in six quinoa varieties from dif ferent origins were analysed. Trials were carried out in an arid region of Argentina’s Nor thwest (Amaicha del Valle, 22º31’S, 65º59’ W, 1,985 m asl) under drought conditions. The varieties used were: Kancolla (Perú) and Sayaña (from Bolivian Altiplano, 3,850 m asl), Quinoa Blanca (from Cochabamaba, Bolivia, 2,570 m asl), Quinoa Roja (from Cangrejillos, Argentina, 3,700 m asl), CICA (originally form Perú but currently cultivated at 2,000 m asl in Argentina) and CO-407 a lowland Chilean variety (140 m asl). In general, our data showed that gs is an important variable in the net CO2 assimilation (Amax) but this control magnitude depends on the considered variety. Highest (31 µmol m-2 s-1 ) and lowest (19 µmol m-2 s-1) Amax values were recorded for CICA and CO-407 varieties. Regarding the carboxylic capacity and intrinsic water use efficiency (iWUE), it may be inferred from the obtained data, that the high altitude varieties (Sayaña and Kancolla) have both, the highest iWUE and carboxylation capacity in relation to other varieties from middle and low altitude (CO-407 and CICA). SLA value did not vary significantly among the studied varieties. Every analysed variety was amphiestomatic with higher stomatal density (SD) on the lower epidermis. A positive linear correlation between Amax and SD was found. The obtained results provide data of unquestionable biological value, which can be useful to varietal breeding studies in middle and high mountain environments.Fil: González, Juan A.. Fundación Miguel Lillo; ArgentinaFil: Ponessa, Graciela I.. Fundación Miguel Lillo; ArgentinaFil: Buedo, Sebastia. E.. Fundación Miguel Lillo; ArgentinaFil: Mercado, Maria Ines. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Prado, Fernando Eduardo. Universidad Nacional de Tucuman. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Catedra de Fisiologia Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Influencia biomecánica de la artroplastia total de rodilla en el apoyo metatarsal

Las articulaciones de la extremidad inferior forman una cadena cinemática y tanto desde el punto de vista normal como patológico se influyen mutuamente. El objetivo de nuestro trabajo es analizar las características del apoyo plantar en 100 pacientes subsidiarios de prótesis total de rodilla que presentan trastornos en la alineación del miembro antes y después de la corrección del eje de la extremidad que supone la cirugía. Además se compara el patrón de apoyo metatarsal con sujetos sanos de características antropométricas similares (grupo control).El genu varo preoperatorio se relaciona con un hiperapoyo de la paleta externa y un hipoapoyo de las paletas central e interna del antepié. En cambio el valgo fisiológico conseguido en el postoperatorio se corresponde con un patrón de apoyo metatarsal al año y a los dos años similar al del grupo control con pequeñas variaciones.Peer Reviewe

Uterine sarcomas: clinical practice guidelines for diagnosis, treatment, and follow-up, by Spanish group for research on sarcomas (GEIS)

Adenosarcoma; Guidelines; Uterine sarcomaAdenosarcoma; Pautas; Sarcoma uterinoAdenosarcoma; Pautes; Sarcoma uteríUterine sarcomas are very infrequent and heterogeneous entities. Due to its rarity, pathological diagnosis, surgical management, and systemic treatment are challenging. Treatment decision process in these tumors should be taken in a multidisciplinary tumor board. Available evidence is low and, in many cases, based on case series or clinical trials in which these tumors have been included with other soft tissue sarcoma. In these guidelines, we have tried to summarize the most relevant evidence in the diagnosis, staging, pathological disparities, surgical management, systemic treatment, and follow-up of uterine sarcomas

Vacuum-Deposited Cesium Tin Iodide Thin Films with Tunable Thermoelectric Properties

Most current thermoelectric materials have important drawbacks, such as toxicity, scarceness, and peak operating temperatures above 300 °C. Herein, we report the thermoelectric properties of different crystalline phases of Sn-based perovskite thin films. The 2D phase, Cs2SnI4, is obtained through vacuum thermal deposition and easily converted into the black β phase of CsSnI3 (B-β CsSnI3) by annealing at 150 °C. B-β CsSnI3 is a p-type semiconductor with a figure of merit (ZT) ranging from 0.021 to 0.033 for temperatures below 100 °C, which makes it a promising candidate to power small electronic devices such as wearable sensors which may be interconnected in the so-called Internet of Things. The B-β phase is stable in nitrogen, whereas it spontaneously oxidizes to Cs2SnI6 upon exposure to air. Cs2SnI6 shows a negative Seebeck coefficient and an ultralow thermal conductivity. However, the ZT values are 1 order of magnitude lower than for B-β CsSnI3 due to a considerably lower electrical conductivity

Quality Legume-Based Forage Systems for Contrasting Environments: COST Action 852

Agricultural systems that reduce environmental degradation, sustain agricultural productivity and economic viability, maintain stable rural communities, enhance the quality of life and respond to increasing demand for livestock products are promoted in developed countries. Though major challenges exist, forage legumes, adapted to a wide range of soil types, climatic conditions and management systems, will become increasingly important components of sustainable agricultural production systems in Europe. Temporal and spatial variation in legume performance often occurs. Compared to pure grass systems, legume-based systems may lead to increased N losses. To what extent ruminants can use the protein from forage legumes, and whether there are differences among species and cultivars are unknown. To improve reliability and the range of forage legumes, we must understand the constraints of environment, the reasons for divergence between species potential and actual performance and the most efficient way to use the herbage. The COST Action 852 - Quality legume-based forage systems for contrasting environments was set up to help resolve some of these questions

Pulsed Laser Deposition of Cs2AgBiBr6: from Mechanochemically Synthesized Powders to Dry, Single-Step Deposition

Cs2AgBiBr6 has been proposed as a promising lead-free and stable double perovskite alternative to hybrid and lead-based perovskites. However, the low solubility of precursors during wet synthesis, or the distinct volatility of components during evaporation, results in complex multistep synthesis approaches, hampering the widespread employment of Cs2AgBiBr6 films. Here, we present pulsed laser deposition of Cs2AgBiBr6 films as a dry, single-step and single-source deposition approach for high-quality film formation. Cs2AgBiBr6 powders were prepared by mechanochemical synthesis and pressed into a solid target maintaining phase purity. Controlled laser ablation of the double perovskite target in vacuum and a substrate temperature of 200 °C results in the formation of highly crystalline Cs2AgBiBr6 films. We discuss the importance of deposition pressure to achieve stoichiometric transfer and of substrate temperature during PLD growth to obtain high-quality Cs2AgBiBr6 films with grain sizes > 200 nm. This work demonstrates the potential of PLD, an established technique in the semiconductor industry, to deposit complex halide perovskite materials while being compatible with optoelectronic device fabrication, such as UV and X-ray detectors

Highly Luminescent Transparent Cs2AgxNa1−xBiyIn1−yCl6 Perovskite Films Produced by Single-Source Vacuum Deposition

Thermal deposition of halide perovskites as a universal and scalable route to transparent thin films becomes highly challenging in the case of lead-free double perovskites, requiring the evaporation dynamics of multiple metal halide sources to be balanced or a single-phase precursor preliminary synthesized to achieve a reliable control over the composition and the phase of the final films. In the present Letter, the feasibility of the single-source vacuum deposition of microcrystalline Cs2AgxNa1-xBiyIn1-yCl6 double perovskites into corresponding transparent nanocrystalline films while preserving the bulk spectral and structural properties is shown. The perovskite films produced from the most emissive powders with x = 0.40 and y = 0.01 revealed a photoluminescence quantum yield of 85%, highlighting thermal evaporation as a promising approach to functional perovskite-based optical materials