327 research outputs found
Comparison of Maldi-Tof with gene sequencing in bacteria isolates from plants belonging to family Rhizobiaceae
Comunicaciones a congreso
Bisutería a base de fruta deshidratada elaborada artesanalmente
El presente trabajo analiza el mercado de la joyería artesanal en la Región de Tuxpan, Ver., con el fin de ofrecer una visión global y orientar a los emprendedores que se encuentran en el proceso de comercialización de bisutería artesanal obteniendo un conocimiento previo, intentando conseguir el éxito en sus proyectos. El sector de la bisutería en México ha experimentado profundos cambios con la llegada masiva de productos asiáticos al mercado, esto, debido a que estos son de muy bajo costo y lo que ha influido de manera radical en la producción local, impactando directamente en el volumen de la comercialización nacional y a las exportaciones, provocando caídas constantes en ambas cifras. Sin embargo, las importaciones crecen cada año desde 2002, México, tradicionalmente es joyero, donde los principales centros de producción están ubicados en Guadalajara y México, DF. La bisutería es una joyería artesanal y tradicional, que es consumida, no tan solo por mujeres, sin no también por hombres. La demanda de bisutería ha crecido y mantiene su tendencia de crecimiento, debido a que es un producto que permite seguir las tendencias de la moda de una manera más económica y segura que la joyería. El motivo que impulsa a la compra de bisutería es más emocional que racional, y su asociación con las tendencias cambiantes de la moda hace que el ciclo del producto sea más corto
Ceres Scales Ground Validation Campaigns for Gerb. Assessment of the Valencia Anchor Station Capabilities
Proceedings del 3rd MSG RAO Workshop, celebrado el 15 de junio de 2006 en Helsinki, Finlandia.The Valencia Anchor Station (VAS) was set up by the
University of Valencia at the natural region of UtielRequena Plateau in 2001. The plateau is a large and
reasonably homogeneous area suitable for validation of
low spatial resolution satellite data and products such
as GERB's. In the framework of the EUMETSAT/ESA
MSG-RAO Project no. 138 GIST Proposal for
Calibration/Validation of SEVIRI and GERB, and of
the Spanish Research Programme on Space Project
SCALES (SEVIRI & GERB Cal/Val Area for Largescale Field ExperimentS), three GERB ground
validation campaigns have so far been carried out at the
VAS under different land surface conditions. CERES
instruments onboard NASA EOS Aqua and Terra
satellites, operating in PAPS (Programmable Azimuth
Plane Scanning) mode, have generously provided
additional SW and LW radiance measurements to
support validation efforts. These have shown to be
most valuable as intermediate validation step between
ground measurements and the large GERB pixel size
Observation of the Crab Nebula with the HAWC Gamma-Ray Observatory
The Crab Nebula is the brightest TeV gamma-ray source in the sky and has been
used for the past 25 years as a reference source in TeV astronomy, for
calibration and verification of new TeV instruments. The High Altitude Water
Cherenkov Observatory (HAWC), completed in early 2015, has been used to observe
the Crab Nebula at high significance across nearly the full spectrum of
energies to which HAWC is sensitive. HAWC is unique for its wide field-of-view,
nearly 2 sr at any instant, and its high-energy reach, up to 100 TeV. HAWC's
sensitivity improves with the gamma-ray energy. Above 1 TeV the
sensitivity is driven by the best background rejection and angular resolution
ever achieved for a wide-field ground array.
We present a time-integrated analysis of the Crab using 507 live days of HAWC
data from 2014 November to 2016 June. The spectrum of the Crab is fit to a
function of the form . The data is well-fit with values of
, , and
log when
is fixed at 7 TeV and the fit applies between 1 and 37 TeV. Study of the
systematic errors in this HAWC measurement is discussed and estimated to be
50\% in the photon flux between 1 and 37 TeV.
Confirmation of the Crab flux serves to establish the HAWC instrument's
sensitivity for surveys of the sky. The HAWC survey will exceed sensitivity of
current-generation observatories and open a new view of 2/3 of the sky above 10
TeV.Comment: Submitted 2017/01/06 to the Astrophysical Journa
Daily monitoring of TeV gamma-ray emission from Mrk 421, Mrk 501, and the Crab Nebula with HAWC
We present results from daily monitoring of gamma rays in the energy range
to TeV with the first 17 months of data from the High
Altitude Water Cherenkov (HAWC) Observatory. Its wide field of view of 2
steradians and duty cycle of % are unique features compared to other TeV
observatories that allow us to observe every source that transits over HAWC for
up to hours each sidereal day. This regular sampling yields
unprecedented light curves from unbiased measurements that are independent of
seasons or weather conditions. For the Crab Nebula as a reference source we
find no variability in the TeV band. Our main focus is the study of the TeV
blazars Markarian (Mrk) 421 and Mrk 501. A spectral fit for Mrk 421 yields a
power law index and
an exponential cut-off
TeV. For Mrk 501, we find an index and exponential cut-off TeV. The light curves for both sources show clear
variability and a Bayesian analysis is applied to identify changes between flux
states. The highest per-transit fluxes observed from Mrk 421 exceed the Crab
Nebula flux by a factor of approximately five. For Mrk 501, several transits
show fluxes in excess of three times the Crab Nebula flux. In a comparison to
lower energy gamma-ray and X-ray monitoring data with comparable sampling we
cannot identify clear counterparts for the most significant flaring features
observed by HAWC.Comment: 18 pages, 10 figures, accepted for publication in The Astrophysical
Journa
All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV
We report on the measurement of the all-particle cosmic ray energy spectrum
with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range
10 to 500 TeV. HAWC is a ground based air-shower array deployed on the slopes
of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to
gamma rays and cosmic rays at TeV energies. The data used in this work were
taken from 234 days between June 2016 to February 2017. The primary cosmic-ray
energy is determined with a maximum likelihood approach using the particle
density as a function of distance to the shower core. Introducing quality cuts
to isolate events with shower cores landing on the array, the reconstructed
energy distribution is unfolded iteratively. The measured all-particle spectrum
is consistent with a broken power law with an index of prior to
a break at ) TeV, followed by an index of . The
spectrum also respresents a single measurement that spans the energy range
between direct detection and ground based experiments. As a verification of the
detector response, the energy scale and angular resolution are validated by
observation of the cosmic ray Moon shadow's dependence on energy.Comment: 16 pages, 11 figures, 4 tables, submission to Physical Review
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