973 research outputs found
Making a “malherbario” as an input for the development of competencies for the “Weed control” course.
La falta de insumos para desarrollar el proceso de enseñanza- aprendizaje en la asignatura de Control de malezas, así como el contar con un solo texto guía desactualizado y ciertas restricciones para salidas de campo, motivaron la elaboración de material didáctico de apoyo con materia prima del sector. El proceso innovador se generó con la participación de los estudiantes para la construcción de un herbario propio, al cual se le denominó “malherbario”. Este sirvió para la consolidación de los contenidos y de la información teórica recibida en clase, a través del desarrollo de los tres saberes, y en especial del saber hacer. La acción educativa permitió la generación de competencias específicas que permiten al estudiante ser capaz de producir una respuesta propia que no había sido previamente memorizada.Lack of inputs to carry out the teaching-learning process in the Weed control course as well as having a single outdated guidebook and certain restrictions for field trips led to the creation of teaching support material using raw material of the surrounding areas. The innovative process was fostered with the participation of students for making their own herbarium, called “malherbario”. This served to strengthen the contents and the theoretical information received in class, through the development of three types of knowledge, in particular the know-how. The educational action allowed the development of specific competencies that enable students to be capable of producing their own response that had not been previously memorized
Enhanced Parallel Generation of Tree Structures for the Recognition of 3D Images
Segmentations of a digital object based on a connectivity
criterion at n-xel or sub-n-xel level are useful tools in image topological
analysis and recognition. Working with cell complex analogous of digital
objects, an example of this kind of segmentation is that obtained from
the combinatorial representation so called Homological Spanning Forest
(HSF, for short) which, informally, classifies the cells of the complex as
belonging to regions containing the maximal number of cells sharing the
same homological (algebraic homology with coefficient in a field) information.
We design here a parallel method for computing a HSF (using
homology with coefficients in Z/2Z) of a 3D digital object. If this object
is included in a 3D image of m1 × m2 × m3 voxels, its theoretical time
complexity order is near O(log(m1 + m2 + m3)), under the assumption
that a processing element is available for each voxel. A prototype implementation
validating our results has been written and several synthetic,
random and medical tridimensional images have been used for testing.
The experiments allow us to assert that the number of iterations in which
the homological information is found varies only to a small extent from
the theoretical computational time.Ministerio de Economía y Competitividad MTM2016-81030-
Ideas and perspectives: Carbon leaks from flooded land: do we need to replumb the inland water active pipe?
At the global scale, inland waters are a significant source of atmospheric
carbon (C), particularly in the tropics. The active pipe concept predicts
that C emissions from streams, lakes and rivers are largely fuelled by
terrestrial ecosystems. The traditionally recognized C transfer mechanisms
from terrestrial to aquatic systems are surface runoff and groundwater
drainage. We present here a series of arguments that support the idea that
land flooding is an additional significant process that fuels inland waters
with C at the global scale. Whether the majority of CO2 emitted by
rivers comes from floodable land (approximately 10 % of the continents) or
from well-drained land is a fundamental question that impacts our capacity
to predict how these C fluxes might change in the future. Using classical
concepts in ecology, we propose, as a necessary step forward, an update of
the active pipe concept that differentiates floodable land from drained
land. Contrarily to well-drained land, many wetlands (in particular riparian
and littoral wetlands) combine strong hydrological connectivity with inland
waters, high productivity assimilating CO2 from the atmosphere, direct
transfer of litter and exudation products to water and waterlogged soils, a
generally dominant allocation of ecosystem respiration (ER) below the water
surface and a slow gas-exchange rate at the water–air interface. These
properties force plants to pump atmospheric C to wetland waters and, when
hydrology is favourable, to inland waters as organic C and dissolved
CO2. This wetland CO2 pump may contribute disproportionately to
CO2 emissions from inland waters, particularly in the tropics where
80 % of the global CO2 emissions to the atmosphere occur. In future
studies, more care must be taken in the way that vertical and horizontal C
fluxes are conceptualized along watersheds, and 2-D models that adequately
account for the hydrological export of all C species are necessary. In
flooded ecosystems, significant effort should be dedicated to quantifying
the components of primary production and respiration by the submerged and
emerged part of the ecosystem community and to using these metabolic rates in
coupled hydrological–biogeochemical models. The construction of a global
typology of wetlands that includes productivity, gas fluxes and hydrological
connectivity with inland waters also appears necessary to adequately
integrate continental C fluxes at the global scale.</p
Symmetry issues in Directly Irradiated Targets
In direct drive Inertial Confinement Fusion (ICF), the typical laser beam to laser beam angle is around 30o. This fact makes the study of the irradiation symmetry agenuine 3D problem. In this paper we use the three dimensional version of the MULTI hydrocode to assess the symmetry of such ICF implosions. More specifically, we study a shock-ignition proposal for the Laser-M´egajoule facility (LMJ) in which two of the equatorial beam cones are used to implode and pre compress a spherical capsule (the “reference” capsule of HiPER project) made of 0.59 mg of pure Deuterium-Tritium mixture. The symmetry of this scheme is analysed and optimized to get a design inside the operating limits of LMJ. The studied configuration has been found essentially axial-symmetric, so that the use of 2D hydrocodes would be appropriate for this specific situatio
Symmetry Issues in Directly Irradiated Targets
In direct drive Inertial Confinement Fusion (ICF), the typical laser beam to laser beam angle is around 30o. This fact makes the study of the irradiation symmetry agenuine 3D problem. In this paper we use the three dimensional version of the MULTI hydrocode to assess the symmetry of such ICF implosions. More specifically, we study a shock-ignition proposal for the Laser-M´egajoule facility (LMJ) in which two of the equatorial beam cones are used to implode and pre compress a spherical capsule (the “reference” capsule of HiPER project) made of 0.59 mg of pure Deuterium-Tritium mixture. The symmetry of this scheme is analysed and optimized to get a design inside the operating limits of LMJ. The studied configuration has been found essentially axial-symmetric, so that the use of 2D hydrocodes would be appropriate for this specific situation
Low initial aspect-ratio direct-drive target designs for shock- or self-ignition in the context of the laser Megajoule
Analysis of low initial aspect ratio direct-drive target designs is carried out by varying the implosion velocity and the fuel mass. Starting from two different spherical targets with a given 300?g-DT mass, optimization of laser pulse and drive power allows to obtain a set of target seeds referenced by their peak implosion velocities and initial aspect ratio (A = 3 and A = 5). Self-ignition is achieved with higher implosion velocity for A = 5-design than for A = 3-design. Then, rescaling is done to extend the set of designs to a huge amount of mass, peak kinetic energies and peak areal densities. Self-ignition kinetic energy threshold Ek is characterized by a dependance of Ek ? v? with ?-values which depart from self-ignition models. Nevertheless, self-ignition energy is seen lower for smaller initial aspect ratio. An analysis of Two-Plasmons Decay threshold and Rayleigh?Taylor instability e-folding is carried out and it is shown that two-plasmon decay threshold is always overpassed for all designs. The hydrodynamic stability analysis is performed by embedded models to deal with linear and non-linear regime. It is found that the A = 5-designs are always at the limit of disruption of the shell
Role of Enzymatic Reactions in Meat Processing and Use of Emerging Technologies for Process Intensification
Meat processing involves different transformations in the animal muscle after slaughtering, which results in changes in tenderness, aroma and colour, determining the quality of the final meat product. Enzymatic glycolysis, proteolysis and lipolysis play a key role in the conversion of muscle into meat. The accurate control of enzymatic reactions in meat muscle is complicated due to the numerous influential factors, as well as its low reaction rate. Moreover, exogenous enzymes are also used in the meat industry to produce restructured products (transglutaminase), to obtain bioactive peptides (peptides with antioxidant, antihypertensive and gastrointestinal activity) and to promote meat tenderization (papain, bromelain, ficin, zingibain, cucumisin and actinidin). Emerging technologies, such as ultrasound (US), pulsed electric fields (PEF), moderate electric fields (MEF), high-pressure processing (HPP) or supercritical CO2 (SC-CO2), have been used to intensify enzymatic reactions in different food applications. This review aims to provide an overview of the enzymatic reactions taking place during the processing of meat products, how they could be intensified by using emerging technologies and envisage potential applications.This research was financially supported by the “Ministerio de Economía y Competitividad (MINECO)” and the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)” in Spain (Projects RTA2017-00024-C04-03 and RTA2017-00024-C04-02).info:eu-repo/semantics/publishedVersio
Systematic analysis of direct-drive baseline designs for shock ignition with the Laser MégaJoule
We present direct-drive target design studies for the laser mégajoule using two distinct initial aspect ratios (A = 34 and A = 5). Laser pulse shapes are optimized by a random walk method and drive power variations are used to cover a wide variety of implosion velocities between 260 km/s and 365 km/s. For selected implosion velocities and for each initial aspect ratio, scaled-target families are built in order to find self-ignition threshold. High-gain shock ignition is also investigated in the context of Laser MégaJoule for marginally igniting targets below their own self-ignition threshold
Direct-Drive Shock-Ignition for the Laser Megajoule.
We present a review of direct-drive shock ignition studies done as alternative for the Laser Mega-Joule to achieve high thermonuclear gain. One-dimensional analysis of HiPER-like Shock-ignited target designs is presented. It is shown that high gain can be achieved with shock ignition for designs which do not ignite only from the laser compression. Shock ignition is achieved for different targets of the fast ignition family which are driven by an absorbed energy between 100 kJ and 850kJ and deliver thermonuclear energies between 10-130 MJ. Shock-Ignition of Direct-Drive Double-Shell non-cryogenic target is also addressed. 2D results concerning the LMJ irradiation geometry are presented. Few systematic analyses are performed for the fuel assembly irradiation uniformity using the whole LMJ configuration or a part of the facility, and for the ignitor spike uniformity. Solutions for fuel assembly and shock ignition on LMJ using 2D calculations are presented. It is shown that high-gain shock-ignition is possible with intensity of each quad less than 1e15 W/cm2but low modes asymmetries displace the ignitor power in the spike towards higher powers
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