Validation of compact models of microcantilever actuators for RF-MEMS application

Microcantilever specimens for in-plane and out-ofplane bending tests are here analyzed. Experimental validation of 2D and 3D numerical models is performed. Main features of in-plane and out-of-plane layouts are then discussed. Effectiveness of plane models to predict pull-in in presence of geometric nonlinearity due to a large tip displacement and initial curvature of microbeam is investigated. The paper is aimed to discuss the capability of 2D models to be used as compact tools to substitute some model order reduction techniques, which appear unsuitable in presence of both electromechanical and geometric nonlinearities.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Main factors influencing floral differentiation and fruit establishment in squash (Cucurbita spp.) = Principales factores que influyen en la diferenciación floral y el cuaje de frutos en zapallo (Cucurbita spp.)

Different agronomic practices can be implemented to increase productivity in squashes (Cucurbita spp.), although they do not always render the same results. They depend on environmental factors such as temperature, environmental humidity, water quality as well as nutrient availability in the soil, which among other variables influence maturation precocity, culinary quality and fruit preservation capacity. In this context, it is relevant to know the way in which flowering and fruit settling are being influenced, in order to understand which conditions are determining the best performance in yield, quality as well as fruit conservation. There is a lot of information about these factors, but it is scattered, which makes it difficult to answer questions that may arise about the influence of the genetic basis and the environment, as well as the hormonal processes in response to the signals of the latter. The objective of this literature review is to update the available information on the factors that influence the processes of flowering and establishment of the squash fruits, and to extract central concepts that contribute to this better understanding. Each factor is analyzed and the relationships that favor productivity are established, emphasizing on "Anco" squashes (Butternut type), which are the most cultivated in Argentina.Diferentes prácticas agronómicas pueden implementarse para aumentar la productividad en los zapallos pero no siempre dan los mismos resultados. Dependen de factores ambientales, como la temperatura, la humedad ambiental, la calidad del agua de riego y la disponibilidad de nutrientes en el suelo, que influyen sobre la precocidad de maduración, la calidad culinaria y la capacidad de conservación de los frutos, entre otras variables. Conocer cómo actúan los diferentes factores sobre la floración y el cuaje permitirá comprender cuáles son las condiciones que determinan las mejores características de rendimiento, calidad y conservación de los frutos. Existe cuantiosa información sobre estos factores, pero la misma se encuentra dispersa, lo que dificulta responder a los interrogantes que pudieran surgir acerca de la influencia que tienen la base genética y el ambiente, así como los procesos hormonales en respuesta a las señales de este último. El objetivo de esta revisión bibliográfica es actualizar la información disponible sobre los factores que influyen en los procesos de floración y establecimiento de los frutos de zapallo, para extraer conceptos centrales que contribuyan a esa mejor comprensión. Se analiza cada uno de ellos y se establecen cuáles son las relaciones que favorecen la productividad, haciendo hincapié en los zapallos tipo “Anco”, que son los más cultivados en Argentina.EEA La ConsultaFil: Della Gaspera, Pedro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Portela, José Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentin

One-step synthesis of porous transparent conductive oxides by hierarchical self-assembly of aluminum-doped ZnO nanoparticles

Transparent conductive oxides (TCOs) are highly desirable for numerous applications ranging from photovoltaics to light-emitting diodes and photoelectrochemical devices. Despite progress, it remains challenging to fabricate porous TCOs (pTCOs) that may provide, for instance, a hierarchical nanostructured morphology for the separation of photoexcited hole/electron couples. Here, we present a facile process for the fabrication of porous architectures of aluminum-doped zinc oxide (AZO), a low-cost and earth-abundant transparent conductive oxide. Three-dimensional nanostructured films of AZO with tunable porosities from 10 to 98% were rapidly self-assembled from flame-made nanoparticle aerosols. Successful Al doping was confirmed by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, elemental mapping, X-ray diffraction, and Fourier transform infrared spectroscopy. An optimal Al-doping level of 1% was found to induce the highest material conductivity, while a higher amount led to partial segregation and formation of aluminum oxide domains. A controllable semiconducting to conducting behavior with a resistivity change of more than 4 orders of magnitudes from about 3 × 102 to 9.4 × 106 ω cm was observed by increasing the AZO film porosity from 10 to 98%. While the denser AZO morphologies may find immediate application as transparent electrodes, we demonstrate that the ultraporous semiconducting layers have potential as a light-driven gas sensor, showing a high response of 1.92-1 ppm of ethanol at room temperature. We believe that these tunable porous transparent conductive oxides and their scalable fabrication method may provide a highly performing material for future optoelectronic devices.</p

Zinc Titanate Nanoarrays with Superior Optoelectrochemical Properties for Chemical Sensing

In this report, the gas sensing performance of zinc titanate (ZnTiO3) nanoarrays (NAs) synthesized by coating hydrothermally formed zinc oxide (ZnO) NAs with TiO2 using low-temperature chemical vapor deposition is presented. By controlling the annealing temperature, diffusion of ZnO into TiO2 forms a mixed oxide of ZnTiO3 NAs. The uniformity and the electrical properties of ZnTiO3 NAs made them ideal for light-activated acetone gas sensing applications for which such materials are not well studied. The acetone sensing performance of the ZnTiO3 NAs is tested by biasing the sensor with voltages from 0.1 to 9 V dc in an amperometric mode. An increase in the applied bias was found to increase the sensitivity of the device toward acetone under photoinduced and nonphotoinduced (dark) conditions. When illuminated with 365 nm UV light, the sensitivity was observed to increase by 3.4 times toward 12.5 ppm acetone at 350 °C with an applied bias of 9 V, as compared to dark conditions. The sensor was also observed to have significantly reduced the adsorption time, desorption time, and limit of detection (LoD) when excited by the light source. For example, LoD of the sensor in the dark and under UV light at 350 °C with a 9 V bias is found to be 80 and 10 ppb, respectively. The described approach also enabled acetone sensing at an operating temperature down to 45 °C with a repeatability of >99% and a LoD of 90 ppb when operated under light, thus indicating that the ZnTiO3 NAs are a promising material for low concentration acetone gas sensing applications.The support from the Australian Research Council through Discovery Project DP150101939 is gratefully acknowledged. R.K.C.B. acknowledges the financial assistance of the RMIT University HDR publication grant. A.E.K. acknowledges the RMIT Vice Chancellor fellowship scheme

Myelin/oligodendrocyte glycoprotein–deficient (MOG-deficient) mice reveal lack of immune tolerance to MOG in wild-type mice

We studied the immunological basis for the very potent encephalitogenicity of myelin/oligodendrocyte glycoprotein (MOG), a minor component of myelin in the CNS that is widely used to induce experimental autoimmune encephalomyelitis (EAE). For this purpose, we generated a mutant mouse lacking a functional mog gene. This MOG-deficient mouse presents no clinical or histological abnormalities, permitting us to directly assess the role of MOG as a target autoantigen in EAE. In contrast to WT mice, which developed severe EAE following immunization with whole myelin, MOG-deficient mice had a mild phenotype, demonstrating that the anti-MOG response is a major pathogenic component of the autoimmune response directed against myelin. Moreover, while MOG transcripts are expressed in lymphoid organs in minute amounts, both MOG-deficient and WT mice show similar T and B cell responses against the extracellular domain of MOG, including the immunodominant MOG 35–55 T cell epitope. Furthermore, no differences in the fine specificity of the T cell responses to overlapping peptides covering the complete mouse MOG sequence were observed between MOG(+/+) and MOG(–/–) mice. In addition, upon adoptive transfer, MOG-specific T cells from WT mice and those from MOG-deficient mice are equally pathogenic. This total lack of immune tolerance to MOG in WT C57BL/6 mice may be responsible for the high pathogenicity of the anti-MOG immune response as well as the high susceptibility of most animal strains to MOG-induced EAE