693 research outputs found
Determinación de distancias y densidades de siembra en cuatro variedades de maní (Arachis hypogaea L.) de los grupos Español, Virginia y Valencia.
Functional-bandwidth kernel for Support Vector Machine with Functional Data:An alternating optimization algorithm
Functional Data Analysis (FDA) is devoted to the study of data which are functions. Support Vector Ma- chine (SVM) is a benchmark tool for classification, in particular, of functional data. SVM is frequently used with a kernel (e.g.: Gaussian) which involves a scalar bandwidth parameter. In this paper, we pro- pose to use kernels with functional bandwidths. In this way, accuracy may be improved, and the time intervals critical for classification are identified. Tuning the functional parameters of the new kernel is a challenging task expressed as a continuous optimization problem, solved by means of a heuristic. Our experiments with benchmark data sets show the advantages of using functional parameters and the ef- fectiveness of our approach
Innovación en la formación de docentes en modalidades a distancia a través del marco de la gestión del conocimiento
En el presente informe se comparte la experiencia de Gestión del Conocimiento de un grupo de asesores del Centro de Aprendizaje en Red (CAR) del Instituto Tecnológico de Estudios Superiores de Occidente (ITESO) que apoyó a profesores a hacer el tránsito de la educación presencial a un modelo de educación en red y en la red, que es una propuesta que ha apostado a una forma de facilitar el proceso de aprendizaje basado en la autonomía, la interacción, la diversidad, la apertura y la colaboración
DESCRIPTIVE ANALYSIS OF THE SMALL RUMINANT MEAT OFFERING IN PUERTO RICO
DESCRIPTIVE ANALYSIS OF THE SMALL RUMINANT MEAT OFFERING IN PUERTO RIC
Green bottle flies (Calliphoridae, Luciliinae) of Ecuador: geographic distribution, checklist and DNA barcodes
Green bottle flies (Diptera, Calliphoridae, Luciliinae) comprise a diverse and cosmopolitan taxon, known from at least 1,500 species. They have become crucial elements in forensic investigations, as they spend part of their life cycle in decaying remains. Here, we review the distribution of eleven Luciliinae species in Ecuador: the monotypic Blepharicnema and ten Lucilia species. We identified specimens using morphological characters. Additionally, we DNA barcoded 43 specimens from three species using 658bp segments of the standard Cytochrome Oxidase I (COI) mitochondrial gen. Molecular and morphological identifications presented high correspondence, suggesting COI barcodes are an efficient tool for the identification of these three green bottle flies species. Geographical records are biased towards the northern Andean region, particularly near to large urban settlements. We remark the value to applied forensic research of continuous sampling of necrophagous flies under a variety of habitats and crime conditions.Fil: Moreno Coellar, Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Pontificia Universidad Católica del Ecuador; EcuadorFil: Amat, Eduardo. Tecnológico de Antioquia; ColombiaFil: Meneses, Pablo E.. Universidad Regional Amazónica Ikiam; EcuadorFil: Donoso, David A.. Escuela Politécnica Nacional; EcuadorFil: Barragán, Álvaro R.. Pontificia Universidad Católica del Ecuador; Ecuado
Production, preparation and characterization of microalgae-based biopolymer as a potential bioactive film
ABSTRACT: Six microalgae strains were screened according to their biomass productivity and polymer synthesis, showing biomass productivity between 0.14 and 0.68 g/(L center dot d) for a 21-day growth period. Extracellular biopolymers from the spent culture media of Nostoc sp. (No), Synechocystis sp. (Sy), and Porphyridium purpureum (Pp) was obtained, and the yields of the clean biopolymer were 323, 204, and 83 mg/L, respectively. The crude biopolymer was cleaned up using a solid-phase extraction technique. The emulsification index E-24 values for the clean biopolymer were 77.5%, 68.8%, and 73.3% at 0.323, 0.083, and 0.204 mg/mL, respectively. The clean biopolymer of the No strain showed the highest fungal growth inhibition against Fusarium verticillioides (70.2%) and Fusarium sp. (61.4%) at 2.24 mg/mL. In general, transparent and flexible biofilms were prepared using biopolymers of No and Pp. The microstructural analysis revealed the presence of pores and cracks in the biofilms, and the average roughness Ra values are 68.6 and 86.4 nm for No and Pp, respectively, and the root mean square roughness Rq values are 86.2 and 107.2 nm for No and Pp, respectively.info:eu-repo/semantics/publishedVersio
A multiscale material model for metallic powder compaction during hot isostatic pressing
The prediction of the distortions during Near-Net-Shape Hot Isostatic Pressing (NNS-HIP) is an intrinsic multiscale problem where the local interactions among particles determine the macroscopic distortions taking place
during the sintering and densification of a component. In this work, a multiscale approach is proposed to solve
this problem. In particular, a viscoplastic constitutive model capable of predicting macroscopic contractions
during a HIP process with high accuracy has been developed, implemented and validated. The macroscopic
model incorporates the mechanical behaviour predicted at the meso-scale by means of multiple-particle finite
element models (MP-FEM) of an agglomerate of powder particles. The model is validated through the prediction
of distortions during HIP of a full scale industrial case. It is concluded that adding the microscopic information of
the HIP process to simulate the contractions at the macroscopic level results in a considerable improvement of
the accuracy of the predictions
Gas geochemistry for the Los Azufres (Michoacán) geothermal reservoir, México
Gas data of the Los Azufres geothermal field were analyzed using a method based on equilibrium of the Fischer-
Tropsch (FT) reaction: CH4 + 2H2O = 4H2 +CO2 and on the combined pyrite-hematite-magnetite (HSH2) reactions:
5/4 H2 +3/2 FeS2 +3/4 Fe2O3 + 7/4 H2O = 3 H2S +Fe3O4 in order to estimate reservoir temperature and
excess steam. The solution of equilibrium equations produces a grid (FT-HSH2). This method is suitable for
reservoirs with relatively high H2S but low H2 and NH3 concentrations in the fluid as is the case of the Los
Azufres well discharges. Reservoir temperature and reservoir excess steam values were estimated for initial and
present conditions in representative wells of the field to study the evolution of fluids, because of exploitation and
waste fluids reinjection. This method was very useful in estimating reservoir temperatures in vapor wells, while
in two-phase wells it was found that as the well produces a smaller fraction of water, the reservoir temperature
estimation agrees qualitatively with results from cationic or silica geothermometers. For liquid-dominated wells
the reservoir temperature estimations agree with temperatures obtained from the well simulator WELFLO. This indicates
that FT-HSH2 results provide the temperature of the fluid entering the well where the last equilibrium
occurs. Results show a decrease in reservoir temperatures in the southern zone of the field where intensive reinjection
takes place. With exploitation, it was also noted that the deep liquid phase in the reservoir is changing to
two-phase increasing the reservoir steam fraction and the non-condensable gases in well discharges
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