1,752 research outputs found
Genealogical data of Boer and Nubian goats in Mexico
The pedigree file of the Boer and Nubian goat breeds in Mexico was constructed using the national database provided by the Asociación Mexicana de Criadores de Ganado Caprino de Registro. Field technicians routinely updated the goat national database by recording information from flocks participating in the performance-recording system. Information on animal identification number, parents, birth date, sex, breed, and farm of origin were used to undertake pedigree analyses using the ENDOG program (version 4.8). This paper presents a pedigree data file, tables and figures of characteristics of pedigree data, pedigree analyses, pedigree integrity, effective population size and genetic conservation index. The data can be used to estimate other population parameters, to monitor the genetic diversity of the Boer and Nubian goat breeds in Mexico, and also to design balanced breeding programs, maintaining genetic variation at reasonable levels and maximizing genetic progress in these populations.202
Dispersion of niquel on the microstructure in magnesium based alloys for hydrogen storage
AbstractMg–Xwt.%Ni (X = 5 and 20) alloys have been prepared by mechanical alloying using milling times of 15 and 30 h in a planetary ball milling to know the effects of magnesium with the addition of Ni as catalyst, dispersion on the microstructure, area surface and the efficiency of hydrogen storage. SEM-EDS, XRD and ImageJ® software have been used to characterize the microstructure and chemical composition of the alloys. Hydriding experiments were performed as batch-type tests at 200, 250 and 300 °C under 2 MPa H2 pressure during 30 min. These experiments resulted in varying amounts of MgH2 in the hydrided powders depending on composition and hydriding conditions. The best results point to an optimum Ni dispersion, which in turn depends on Ni content and milling time
Composite Material for Supercapacitors Formed by Polymerization of Aniline in the Presence of Graphene Oxide Nanosheets
The composite material was obtained by the polymerization of aniline in the presence of graphene oxide
nanosheets (GONS). The resulting composite PANi (72%) - GONS (28%) was investigated by methods
such as XPS, TGA, Raman and IR spectroscopy, and so on. It was established that a partial reduction of
graphene oxide takes part in course of the polymerization. Specific capacitance of the PANi-GONS electrode
in 1M H2SO4, corresponding to its discharge from 0.700 to 0.052 V, was found to be 547 F/g. But, if in
the calculation of the capacitance include a shallow part of the discharge curve (below 0.15 V), one can obtain
the value of specific capacity greater than 1200 F/g.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3523
Non-random distribution of biocrust in a natural arid environment in the northern mexican plateau
Abstract. Biocrust, as photosynthetic organisms, has been considered to show an inversely proportional relationship with vascular plant cover. However, some studies report association and facilitation relationships between them. This research explores whether i) biocrust is associated with shrub species, ii) biocrust cover is higher in undershrub microenvironments than in open areas between plants and, iii) soil moisture and solar radiation affect biocrust distribution. Biocrust cover was analyzed by morphotype in microenvironments under the canopy of two dominant shrub species (Larrea tridentata and Parthenium incanum) and in open areas. Soil moisture and solar radiation were recorded at each microenvironment. Thirty-three interception lines (975 points) were used to analyze the association between vascular plants and biocrust and 20 sampling plots to estimate morphotype cover. Results reveal a positive association between biocrust and plant species compared to open areas. Lichens and cyanobacteria showed a higher cover under L. tridentata than under P. incanum and in open areas, suggesting a species-specific facilitative association with L. tridentata, maybe due to a higher soil water content in this microenvironment. Mosses had lower cover in the open area where the highest solar radiation was recorded. Lichens and cyanobacteria distribution appeared to be related to soil moisture. Keywords: creosote bush, cyanobacteria, lichens, mosses, northeastern Mexic
Specification and Development of a HMI for ADAS, Based in Usability and Accessibility Principles
Traditionally, the design of road vehicle HMI is based in esthetic principles, maintaining it as an attractive factor for possible clients when buying a car. Only recently, ergonomic benefits have been applied to the design of HMIs, mainly following institutional impulses like the European Union one, but whose contribution is not clearly stated nowadays in commercial products. In this paper the authors present a study of the design of an HMI, based in usability and accessibility premises, centering the design in the user, as method to improve safety, making natural the communication with the driver as well as being able to transmitting information to the driver, from basic to the generated by ADAS installed in the car. Following these specifications a set of prototypes have been designed in order to develop a testbed that could be evaluated for a large set of drivers.This work has been supported by the Spanish Ministry of Science and Innovation (TRA2007-67786 and TRA2009-07505) and the CAM project SEGVAUTO-II.Publicad
Numerical analysis of gas-solidsflow hydrodynamics and heat transfer in two outlet configurationindustrial riser using mesoscale theory to predict the interfacialdrag
Se analizan numéricamente dos configuraciones de un riser del proceso FCC variando la disposición de la salida superior, usando un modelo CFD en 2 D que incluye el Modelo de los Dos Fluidos (TMF), la Teoría Cinética del Flujo Granular (KTGF) y como modelo de arrastre el modelo de la Minimización de la Energía Multi-Escala (EMMS). El modelo se resuelve a través del programa ANSYS Fluent® 14.5 solucionando las ecuaciones de balance de masa, momentum y energía; y ecuaciones constitutivas para calcular la interacción entre las fases, la fase sólida con las paredes, y las propiedades de la fase granular. El modelo propuesto en este trabajo predice adecuadamente el comportamiento del flujo gas-sólido, prediciendo diferentes patrones de flujo en las coordenadas axial y radial del riser; así como zonas concentradas y diluidas de sólidos en la parte baja y alta del riser, respectivamente. Las fluctuaciones en la concentración y las velocidades de los sólidos tanto radial como axialmente que se observan son producto del alto grado de mezclado radial que se acentúa cerca de las paredes del riser debido al arrastre considerado por el modelo utilizado. Por otro lado se observa una rápida estabilización térmica radial y axial alcanzando en poco tiempo el estado estacionario. Los perfiles obtenidos en las dos configuraciones analizadas son muy similares, lo que motiva a que en trabajos futuros se analicen otras configuraciones de salida del riser que permitan mejorar los patrones de concentración y velocidades de los sólidos.In the FCC process two configurations riser are numerically analyzed varying the upper outlet orientation using a 2 D CFD model which includes the Two Fluid Model (TFM), Kinetic Theory of Granular Flow (KTGF), and Energy Minimization Multi-Scale (EMMS) theory as drag model. This model is solved using the ANSYS Fluent® 14.5 software, solving the governing equations of mass, momentum, and energy balance; and the constitutive equations to calculate interfacial interaction, wall-solid phase interaction, and granular phase properties. The model proposed in this work properly predicts the gas-solid flow behavior, predicting different solid flow patterns in radial and axial riser directions, as well as concentrated and diluted zones at riser's top and bottom respectively. The radial and axial solids concentration and velocities profiles fluctuations observed are produced by the high radial solid mix which is higher near the riser walls due to drag force considered by the model used. On the other hand, a rapid radial and axial thermal stabilization is observed reaching the steady state rapidly. The profiles obtained from riser configurations analyzed are very similar, so in future works other riser outlets configurations will be analyzed to try to improve the solid concentration and velocity profiles.Peer Reviewe
New acyclic diaminocarbenes cycloplatinated(II) complexes: synthesis, photophysical properties and cytotoxic activity
Among all phosphorescent molecules, cyclometalated platinum(II) complexes have receivedconsiderable attention because of their photophysical properties and potential applications asdopants in OLEDs, LECs, photocatalysts or bioimaging. Another research of relevant interest istheir employment as anticancer drugs with a broader spectrum of action against differenttumours and fewer side effects than the well-known cisplatin. For that reason, the choice of thecyclometalated group and ancillary ligands play an important role not only in emissive behaviorbut also on the biological activity.1N-acyclic diaminocarbenes (ADCs) show several appealing characteristics; they display strongelectron-donating ability with structural flexibility and can be easily prepared. However, thereare only a few examples of ADC-platinum complexes used as perspective metal-based drugs inthe literature.2In this contribution, we describe a series of new luminescent ADC cycloplatinated(II) compoundsfeaturing 2-(2,4-difluorophenyl)pyridine (3) and 2-phenylquinoline (4) cyclometalated groups[Pt(C^N)Cl{C(NHXyl)(NHR)}] (R = Pr a, Benzyl b) obtained by nucleophilic addition of primarypropyl and benzyl amines, to the isocyanide ligand of the corresponding precursors[Pt(C^N)Cl(CNXyl)] (1, 2) recently reported by our group.3 Their optical properties haveexamined and interpreted with the aid of DFT/TD-DFT calculations and, finally, all newcompounds have been screened for their cytotoxic activity against various cancer cell lines
Environment perception based on LIDAR sensors for real road applications
The recent developments in applications that have been designed to increase road safety require reliable and trustworthy sensors. Keeping this in mind, the most up-to-date research in the field of automotive technologies has shown that LIDARs are a very reliable sensor family. In this paper, a new approach to road obstacle classification is proposed and tested. Two different LIDAR sensors are compared by focusing on their main characteristics with respect to road applications. The viability of these sensors in real applications has been tested, where the results of this analysis are presented.The recent developments in applications that have been designed to increase road safety require reliable and trustworthy sensors. Keeping this in mind, the most up-to-date research in the field of automotive technologies has shown that LIDARs are a very reliable sensor family. In this paper, a new approach to road obstacle classification is proposed and tested. Two different LIDAR sensors are compared by focusing on their main characteristics with respect to road applications. The viability of these sensors in real applications has been tested, where the results of this analysis are presented.The work reported in this paper has been partly funded by
the Spanish Ministry of Science and Innovation (TRA2007-
67786-C02-01, TRA2007-67786-C02-02, and TRA2009-
07505) and the CAM project SEGVAUTO-II.Publicad
Limitations of positioning systems for developing digital maps and locating vehicles according to the specifications of future driver assistance systems
Some advanced driver assistance systems require on-the-lane vehicle positioning on accurate digital maps. The combination of high precision global navigation satellite systems and inertial measurement is the most common technique to carry out this precise positioning since in some areas global positioning systems (GPS) signals are lost or degraded. However, real experimental validation of the navigation algorithms (beyond simulation) is one of the most important shortcomings in the state-of-the-art. In this study, a wide set of real experiments have been carried out on real roads, in urban and rural environments, using an instrumented car. A theoretical approach based on the uncertainty propagation law has been set out to evaluate the errors when using only inertial measurement systems and the maximum distance that can be travelled before exceeding the admissible error limits. Results show that it is better to correct GPS positioning when its signal is degraded than to wait until the signal is definitively lost. Furthermore, inertial measurement systems and GPS receivers of different levels of accuracy have been compared in order to determine whether they are suitable for new assistance applications. Experimental data are consistent with the theoretical approach.The work reported in this paper has been partly funded by the Spanish Ministry of Science and Innovation (SIAC project TRA2007-67786-C02-01 and TRA2007-67786-C02-02) and the CAM project SEGVAUTO.Publicad
Long-Term Variations in the Growth and Decay Rates of Sunspot Groups
Using the combined Greenwich (1874-1976) and Solar Optical Observatories
Network (1977-2009) data on sunspot groups, we study the long-term variations
in the mean daily rates of growth and decay of sunspot groups. We find that the
minimum and the maximum values of the annually averaged daily mean growth rates
are ~52% per day and ~183% per day, respectively, whereas the corresponding
values of the annually averaged daily mean decay rates are ~21% per day and
~44% per day, respectively. The average value (over the period 1874-2009) of
the growth rate is about 70% more than that of the decay rate. The growth and
the decay rates vary by about 35% and 13%, respectively, on a 60-year
time-scale. From the beginning of Cycle 23 the growth rate is substantially
decreased and near the end (2007-2008) the growth rate is lowest in the past
about 100 years.Comment: 1 table, 13 figures, accepted by Solar Physic
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