2,775 research outputs found

    Valorization of Microalgae and Energy Resources

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    Microalgae biotechnology has grown very rapidly in the last few decades due to the multiple applications that these microorganisms have from pharmaceuticals and cosmetics to foods/feeds and biofuels. One of the main challenges in expanding this industry is to enlarge the single use of the biomass produced in addition to reducing the high biomass production cost of the current technologies. To overcome this bottleneck, the development of microalgae-based biorefineries has been proposed. The issue is to obtain as many bioproducts as possible from the cultivated biomass, including biofuels. Consequently, biodiesel production (from the lipid fraction), bioethanol (from carbohydrate fraction), and biogas or bio-oil (from the whole biomass) have been posited. In this book chapter, we review the current state of the art in the production of sustainable biofuels from microalgae and analyze the potential of microalgae to contribute to the biofuel sector

    Reactivity of vinyl and alkynyl zirconium complexes with the di-ansa-[1,1′,2,2′-bis(dimethylsilanediyl) dicyclopentadienyl] ligand

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    Vinylation of the chloro–ethyl and dichloro zirconium complexes [Zr(CpSi2Cp)ClX] (CpSi2Cp=1,1′,2,2′-(SiMe2)2(η5-C5H3)2; X=Et, Cl) with one or two equivalents of Mg(CH=CH2)Cl gave the new zirconacyclopentane [Zr(CpSi2Cp){η2-CH2-(CH2)2-CH2}] and (η4-butadiene)zirconium [Zr(CpSi2Cp){η4-(butadiene)}] complexes, respectively. Addition of a toluene solution of PhC=CPh to the zirconacyclopentane compound afforded the zirconacyclopentadiene derivative [Zr(CpSi2Cp){η2-(CPh=CPh-CPh=CPh)}]. Reaction of the chloro–ethyl zirconium complex with LiC=CPh afforded the alkynyl compound [Zr(CpSi2Cp)Et(C=CPh)] which reacted with CN(2,6-Me2C6H3) to give the insertion product [Zr(CpSi2Cp)(C=CPh){η2-C(Et)=N(2,6-Me2C6H3)}]. Reactions of the chloro–ethyl [Zr(CpSi2Cp)EtCl] and alkynyl-ethyl [Zr(CpSi2Cp)Et(C=CPh)] complexes with the Lewis acid B(C6F5)3 yielding various cationic species have been monitored by 1H-NMR spectroscopy. The new complexes reported and their intermediates have been identified by IR and 1H- and 13C-NMR spectroscopy

    Inversion of perturbation series

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    We investigate the inversion of perturbation series and its resummation, and prove that it is related to a recently developed parametric perturbation theory. Results for some illustrative examples show that in some cases series reversion may improve the accuracy of the results

    Improved mechanical stability of HKUST-1 in confined nanospace

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    One of the main concerns in the technological application of several metal–organic frameworks (MOFs) relates to their structural instability under pressure (after a conforming step). Here we report for the first time that mechanical instability can be highly improved via nucleation and growth of MOF nanocrystals in the confined nanospace of activated carbons.Financial support from MINECO projects MAT2013-45008-p and CONCERT Project-NASEMS (PCIN-2013-057) is gratefully acknowledged

    Spike-based VITE control with Dynamic Vision Sensor applied to an Arm Robot.

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    Spike-based motor control is very important in the field of robotics and also for the neuromorphic engineering community to bridge the gap between sensing / processing devices and motor control without losing the spike philosophy that enhances speed response and reduces power consumption. This paper shows an accurate neuro-inspired spike-based system composed of a DVS retina, a visual processing system that detects and tracks objects, and a SVITE motor control, where everything follows the spike-based philosophy. The control system is a spike version of the neuroinspired open loop VITE control algorithm implemented in a couple of FPGA boards: the first one runs the algorithm and the second one drives the motors with spikes. The robotic platform is a low cost arm with four degrees of freedom.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02/01Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0

    Analysis of spatial correlation in predictive models of forest variables that use LiDAR auxiliary information

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    [EN] Accounting for spatial correlation of LiDAR model errors can improve the precision of model-based estimators. To estimate spatial correlation, sample designs that provide close observations are needed, but their implementation might be prohibitively expensive. To quantify the gains obtained by accounting for the spatial correlation of model errors, we examined (i) the spatial correlation patterns of residuals from LiDAR linear models developed to predict volume, total and stem biomass per hectare, quadratic mean diameter (QMD), basal area, mean and dominant height, and stand density and (ii) the impact of field plot size on the spatial correlation patterns in a standwise managed Mediterranean forest in central Spain. For all variables, the correlation range of model residuals consistently increased with plot radius and was always below 60 m except for stand density, where it reached 85 m. Except for QMD, correlation ranges of model residuals were between 1.06 and 8.16 times shorter than those observed for the raw variables. Based on the relatively short correlation ranges observed when the LiDAR metrics were used as predictors, the assumption of independent errors in many forest management inventories seems to be reasonable and appropriate in practice.The authors wish to thank Jay Ver Hoef and Isabel Molina for their valuable comments on earlier versions of the manuscript. The U.S. Bureau of Land Management, the Spanish Ministry of Industry, Tourism and Trade, and the Spanish Ministry of Science and Innovation provided financial support in the framework of the projects "Use of LIDAR and other remote sensing data with FIA plots for mapping forest inventory in Southwest Oregon," InForest II TSI-020100-2009-815, and CGL2010-19591/BTE, respectively.Mauro, F.; Monleón, VJ.; Temesgen, H.; Ruiz Fernández, LÁ. (2017). Analysis of spatial correlation in predictive models of forest variables that use LiDAR auxiliary information. Canadian Journal of Forest Research. 47(6):788-799. https://doi.org/10.1139/cjfr-2016-0296S78879947

    Hemangioma intramuscular: (aportación de 6 casos y revisión de la literatura)

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    Se presentan seis casos de hemangioma intramuscular. Se discute la etiología, histopatología, métodos diagnósticos y el tratamiento óptimo. El tratamiento de elección debe ser la escisión ampliada siempre que ésta sea posible, siendo los resultados satisfactorios.Six cases of haemangioma arising in skeletal muscle are described. The aetiology, pathology, diagnosis and treatment of thes e tumours are discussed. Wide excision remains the treatment of choice whereve r possible with satisfactory results

    High order analysis of the limit cycle of the van der Pol oscillator

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    We have applied the Lindstedt-Poincaré method to study the limit cycle of the van der Pol oscillator, obtaining the numerical coefficients of the series for the period and for the amplitude to order 859. Hermite-Padé approximants have been used to extract the location of the branch cut of the series with unprecedented accuracy (100 digits). Both series have then been resummed using an approach based on Padé approximants, where the exact asymptotic behaviors of the period and the amplitude are taken into account. Our results improve drastically all previous results obtained on this subject.Fil: Amore, Paolo. Universidad de Colima; MéxicoFil: Boyd, John P.. University of Michigan; Estados UnidosFil: Fernández, Francisco Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

    SMOTE for Learning from Imbalanced Data: Progress and Challenges, Marking the 15-year Anniversary

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    The Synthetic Minority Oversampling Technique (SMOTE) preprocessing algorithm is considered \de facto" standard in the framework of learning from imbalanced data. This is due to its simplicity in the design of the procedure, as well as its robustness when applied to di erent type of problems. Since its publication in 2002, SMOTE has proven successful in a variety of applications from several di erent domains. SMOTE has also inspired several approaches to counter the issue of class imbalance, and has also signi cantly contributed to new supervised learning paradigms, including multilabel classi cation, incremental learning, semi-supervised learning, multi-instance learning, among others. It is standard benchmark for learning from imbalanced data. It is also featured in a number of di erent software packages | from open source to commercial. In this paper, marking the fteen year anniversary of SMOTE, we re ect on the SMOTE journey, discuss the current state of a airs with SMOTE, its applications, and also identify the next set of challenges to extend SMOTE for Big Data problems.This work have been partially supported by the Spanish Ministry of Science and Technology under projects TIN2014-57251-P, TIN2015-68454-R and TIN2017-89517-P; the Project 887 BigDaP-TOOLS - Ayudas Fundaci on BBVA a Equipos de Investigaci on Cient ca 2016; and the National Science Foundation (NSF) Grant IIS-1447795

    A Case Study on Vestibular Sensations in Driving Simulators

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    Motion platforms have been used in simulators of all types for several decades. Since it is impossible to reproduce the accelerations of a vehicle without limitations through a physically limited system (platform), it is common to use washout filters and motion cueing algorithms (MCA) to select which accelerations are reproduced and which are not. Despite the time that has passed since their development, most of these algorithms still use the classical washout algorithm. In the use of these MCAs, there is always information that is lost and, if that information is important for the purpose of the simulator (the training simulators), the result obtained by the users of that simulator will not be satisfactory. This paper shows a case study where a BMW 325Xi AUT fitted with a sensor, recorded the accelerations produced in all degrees of freedom (DOF) during several runs, and data have been introduced in mathematical simulation software (washout + kinematics + actuator simulation) of a 6DOF motion platform. The input to the system has been qualitatively compared with the output, observing that most of the simulation adequately reflects the input to the system. Still, there are three events where the accelerations are lost. These events are considered by experts to be of vital importance for the outcome of a learning process in the simulator to be adequat
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