658 research outputs found

    A laser triangulation sensor for vibrational structural analysis and diagnostics

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    The industrial progress has reached a level in which it is necessary to understand the behavior of mechanical components and to monitor their conditions without disassembling them. Nowadays, a suitable methodology is based on vibrational analysis usually performed through acceleration signals measured directly on the system to be tested. However, in the last years, the industrial scenario has deeply changed due to the need for time reduction, in particular, for the control operations at the end of the productive line. The genuine methods based on acceleration measurements, for example, through piezoelectric accelerometers, came into conflict with the industrial need as the sensors used for the quality control have to be easily and fastly mounted and unmounted. A valid alternative is represented by the exploitation of laser triangulation sensors that are able to measure the dynamic displacement in a contactless way, strongly reducing the (un)mounting time. The target of this paper is to highlight pros and cons of the contactless displacement analysis through laser triangulation sensors with respect to the contact one through genuine accelerometers by means of a comparison between the results obtained both for experimental modal analysis and vibrational diagnostics of rotating machines

    Two QTLs govern the resistance to Sclerotinia minor in an interspecific peanut RIL population

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    Sclerotinia blight is a soilborne disease caused by Sclerotinia minor Jagger and can produce severe decrease in yield. Cultural management strategies and chemical treatment are not completely effective; therefore, growing peanut-resistant varieties is likely to be the most effective control method for this disease. Sclerotinia blight resistance has been identified in wild Arachis species and further transferred to peanut elite cultivars. To identify the genome regions conferring Sclerotinia blight resistance within a tetraploid genetic background, this study evaluated a population of recombinant inbred lines (RIL) with introgressed genes from three wild diploid species: A. cardenasii, A. correntina, and A. batizocoi. Two consistent quantitative trait loci (QTLs), qSbIA04 and qSbIB04 located on chromosomes A04 and B04, respectively, were identified. The QTL qSbIA04 was mapped at 56.39 cM explaining 29% of the phenotypic variance and qSbIB04 was mapped at 13.38 cM explaining 22% of the overall phenotypic variance

    Identificación de Germoplasma de maní de criadero el Carmen tolerante a la sequia: aspectos bioquímicos y rendimiento

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    PosterLa sequía estacional es un estrés ambiental que genera pérdidas de rendimiento de alrededor del 30% en el cultivo de maní (Arachis hypogaea) en la Provincia de Córdoba. Una de las estrategias para reducirlas es el desarrollo de nuevas variedades comerciales con mayor tolerancia a la sequía. Desde el año 2016 se está desarrollando un sistema de identificación de materiales tolerantes a sequía provenientes de la colección de germoplasma de Criadero El Carmen, empleando un método estandarizado bajo condiciones controladas, que reduce los tiempos de evaluación al realizarse en etapa vegetativa. Se emplean las respuestas relacionadas al balance osmótico y la fotosíntesis como marcadores fisiológicos que permiten monitorear la tolerancia de los materiales de interés. Previamente, se evaluaron diferentes parámetros bioquímicos registrados en distintos ensayos mediante un análisis de componentes principales (PCA), lo que permitió determinar que los contenidos de prolina, carotenoides y azucares están asociados a una mayor tolerancia a la sequía en estadios tempranos del desarrollo vegetativo. El proyecto tiene como objetivo identificar germoplasma de maní tolerante a la sequía mediante un sistema estandarizado rápido a emplearse en etapas vegetativas bajo condiciones controladas y su validación posterior en la etapa reproductiva.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Guzzo, María Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Posada, G. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Costamagna, C. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Soave, S.J. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Soave, J.H. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Buteler, M.I. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Monteoliva, Mariela Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Monteoliva, Mariela Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); Argentin

    Symbolic dynamics for the NN-centre problem at negative energies

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    We consider the planar NN-centre problem, with homogeneous potentials of degree -\a<0, \a \in [1,2). We prove the existence of infinitely many collisions-free periodic solutions with negative and small energy, for any distribution of the centres inside a compact set. The proof is based upon topological, variational and geometric arguments. The existence result allows to characterize the associated dynamical system with a symbolic dynamics, where the symbols are the partitions of the NN centres in two non-empty sets

    Thirty Years with EoS/G<sup>E</sup> Models - What Have We Learned?

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    Postoperative respiratory failure in liver transplantation: Risk factors and effect on prognosis

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    Background :Postoperative respiratory failure (PRF, namely mechanical ventilation &gt;48 hours) significantly affects morbidity and mortality in liver transplantation (LTx). Previous studies analyzed only one or two categories of PRF risk factors (preoperative, intraoperative or postoperative ones). The aims of this study were to identify PRF predictors, to assess the length of stay (LoS) in ICU and the 90-day survival according to the PRF in LTx patients. Methods: Two classification approaches were used: systematic classification (recipient-related preoperative factors; intraoperative factors; logistic factors; donor factors; postoperative ICU factors; postoperative surgical factors) and patient/organ classification (patient-related general factors; native-liver factors; new-liver factors; kidney factors; heart factors; brain factors; lung factors). Two hundred adult non-acute patients were included. Missing analysis was performed. The competitive role of each factor was assessed. Results: PRF occurred in 36.0% of cases. Among 28 significant PRF predictors at univariate analysis, 6 were excluded because of collinearity, 22 were investigated by ROC curves and by logistic regression analysis. Recipient age (OR = 1.05; p = 0.010), female sex (OR = 2.75; p = 0.018), Model for End-Stage Liver Disease (MELD, OR = 1.09; p&lt;0.001), restrictive lung pattern (OR = 2.49; p = 0.027), intraoperative veno-venous bypass (VVBP, OR = 3.03; p = 0.008), pre-extubation PaCO 2 (OR = 1.11; p = 0.003) and Model for Early Allograft Function (MEAF, OR = 1.37; p&lt;0.001) resulted independent PRF risk factors. As compared to patients without PRF, the PRF-group had longer LoS (10 days IQR 7-18 versus 5 days IQR 4-7, respectively; p&lt;0.001) and lower day-90 survival (86.0% versus 97.6% respectively, p&lt;0.001). Conclusion: In conclusion, MELD, restrictive lung pattern, surgical complexity as captured by VVBP, pre-extubation PaCO 2 and MEAF are the main predictors of PRF in non-acute LTx patients

    Etiologia de manchas de sementes de cultivares de arroz de sequeiro no Centro-Oeste brasileiro.

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    O presente trabalho teve o objetivo de conhecer os fungos que mancham sementes de arroz, estudando a importância de cada um, sua frequência e nível de incidência, baseando-se na correlação da quantidade de cada fungo com a quantidade de mancha de semente de arroz de sequeiro do Centro-Oeste brasileiro
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