1,177 research outputs found
Evaluación de dos porcentajes de drenaje sobre chile dulce (Capsicum annuum) cultivado bajo invernadero
Objective: to evaluate two drainage rates (DR) (10% and 30%) for their effect on the yield and quality of sweet pepper cv. Nathalie grown under greenhouse conditions in two seasons (dry and rainy). Methodology: the crop was grown on coconut fiber as a substrate, and managed with fertigation, and the following variables were evaluated: number of fruits per m2, fruit weight (g), yield (kg/m2), and percentage of total soluble solids (°Brix). Results: With 30% DR, a significantly higher number of fruits per m2 and yield was obtained for the first and commercial qualities, compared to 10% DR. In the rainy season, the number of fruits per m2 and the yield were significantly higher for the first, second, commercial and total qualities, compared to the dry season. The DR did not affect the weight of the fruit or the percentage of total soluble solids. Fruits produced in the dry season showed a higher percentage of total soluble solids, compared to the rainy season. Conclusions: Under the conditions in which the trial was carried out, in the dry season it is recommended to grow sweet pepper with 30% DR, while in the rainy season it is recommended to use 10% DR in order to save water and nutrients, and thus increase the crop profitability without affecting yield.Objetivo: evaluar el efecto de dos porcentajes de drenaje (%D) (10% y 30%) sobre el rendimiento y la calidad del chile dulce cv. Nathalie cultivado bajo invernadero, en dos épocas (seca y lluviosa). Metodología: se usó fibra de coco como sustrato, y se aplicó fertirrigación; se evaluaron las siguientes variables: número de frutos por m2, peso del fruto (g), rendimiento (kg/m2), y porcentaje de sólidos solubles totales (°Brix). Resultados: Con 30%D se obtuvo un número de frutos por m2 y un rendimiento significativamente mayor para las calidades primera y comercial, en comparación con 10%D. En la época lluviosa, el número de frutos por m2 y el rendimiento fueron significativamente superiores para las calidades primera, segunda, comercial y total, en comparación con la época seca. El %D no afectó el peso del fruto ni el porcentaje de sólidos solubles totales. Los frutos producidos en la época seca mostraron un mayor porcentaje de sólidos solubles totales, en comparación con la época lluviosa. Conclusiones: Bajo las condiciones en que se desarrolló el ensayo, en la época seca se recomienda cultivar el chile dulce con 30%D, mientras que en la época lluviosa se recomienda usar 10%D, con el fin de ahorrar agua y nutrientes, y así aumentar la rentabilidad del cultivo sin afectar el rendimiento
Studi Implementasi Pendidikan Karakter Pada Pembelajaran Matematika Pada Kelas Cerdas Istimewa Bakat Istimewa (Cibi) SMP Negeri 2 Surakarta
The objective of research was to describe the implementation of character education to mathematics learning, the constraints the teacher faced and the solution the teachers took to the constraints with the implementation of character education in mathematics learning in the gifted and talented class of SMP Negeri 2 Surakarta. This study was a descriptive qualitative research; the subject of researcher was one mathematics teacher and six students in the grade VII gifted and talented class. Techniques of validating data used were researcher persistence and time triangulation. Techniques of analyzing data used were (1) data reduction, (2) data display, and (3) conclusion drawing and verification. The results of research are as follows. 1) The process of character education implementation to learning was below. (a) The development of logical, critical, creative and innovative thinking character was conducted by means of assignment, directing the students to the correct answer and to make decision with debriefing. (b) The development of hard work character was conducted by means of group assignment. (c) The development of curiosity character was conducted by providing the example of material existing in real life. (d) The development of independency character was conducted by assigning the material reading to be discussed in the next meeting. (e) The development of self-confidence character was conducted by means of facilitating the students writing the result on the blackboard. 2) The constraints the teacher faced and the solutions the teacher took were as follows. (a) In the implementation of logical, critical, creative and innovative thinking character, the students monopolized actively the debriefing process so that the teacher should limit and provide other students the opportunity of asking question. (b) In the implementation of hard work character, not all students in the classroom had equal hard work ethos. The solutions taken were to play motivation video and to convince them about the ability they had, to display the students\u27 work, and to reward the students with the best performance. (c) In the implementation of curiosity character, the students who did not want to think too hard responded poorly to the stimulus given. In this case, the teacher could give reward in the form of mark (grade). (d) In the implementation of self-confidence character, the students with less self-confidence would select the easy assignment in presenting the group assignment, and they explained in very soft voice. The solutions taken were to give more mark to the students explaining group assignment, and to direct the students in the presentation. For teacher independency character, the teacher did not face a significant constraint
Progress in Monte Carlo design and optimization of the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) will be an instrument covering a wide
energy range in very-high-energy (VHE) gamma rays. CTA will include several
types of telescopes, in order to optimize the performance over the whole energy
range. Both large-scale Monte Carlo (MC) simulations of CTA super-sets
(including many different possible CTA layouts as sub-sets) and smaller-scale
simulations dedicated to individual aspects were carried out and are on-going.
We summarize results of the prior round of large-scale simulations, show where
the design has now evolved beyond the conservative assumptions of the prior
round and present first results from the on-going new round of MC simulations.Comment: 4 pages, 5 figures. In Proceedings of the 33rd International Cosmic
Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at
arXiv:1307.223
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
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
Very high energy particle acceleration powered by the jets of the microquasar SS 433
SS 433 is a binary system containing a supergiant star that is overflowing
its Roche lobe with matter accreting onto a compact object (either a black hole
or neutron star). Two jets of ionized matter with a bulk velocity of
extend from the binary, perpendicular to the line of sight, and
terminate inside W50, a supernova remnant that is being distorted by the jets.
SS 433 differs from other microquasars in that the accretion is believed to be
super-Eddington, and the luminosity of the system is erg
s. The lobes of W50 in which the jets terminate, about 40 pc from the
central source, are expected to accelerate charged particles, and indeed radio
and X-ray emission consistent with electron synchrotron emission in a magnetic
field have been observed. At higher energies (>100 GeV), the particle fluxes of
rays from X-ray hotspots around SS 433 have been reported as flux
upper limits. In this energy regime, it has been unclear whether the emission
is dominated by electrons that are interacting with photons from the cosmic
microwave background through inverse-Compton scattering or by protons
interacting with the ambient gas. Here we report TeV -ray observations
of the SS 433/W50 system where the lobes are spatially resolved. The TeV
emission is localized to structures in the lobes, far from the center of the
system where the jets are formed. We have measured photon energies of at least
25 TeV, and these are certainly not Doppler boosted, because of the viewing
geometry. We conclude that the emission from radio to TeV energies is
consistent with a single population of electrons with energies extending to at
least hundreds of TeV in a magnetic field of ~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K.
Fang, C.D. Rho , H. Zhang, H. Zho
Constraining the Ratio in TeV Cosmic Rays with Observations of the Moon Shadow by HAWC
An indirect measurement of the antiproton flux in cosmic rays is possible as
the particles undergo deflection by the geomagnetic field. This effect can be
measured by studying the deficit in the flux, or shadow, created by the Moon as
it absorbs cosmic rays that are headed towards the Earth. The shadow is
displaced from the actual position of the Moon due to geomagnetic deflection,
which is a function of the energy and charge of the cosmic rays. The
displacement provides a natural tool for momentum/charge discrimination that
can be used to study the composition of cosmic rays. Using 33 months of data
comprising more than 80 billion cosmic rays measured by the High Altitude Water
Cherenkov (HAWC) observatory, we have analyzed the Moon shadow to search for
TeV antiprotons in cosmic rays. We present our first upper limits on the
fraction, which in the absence of any direct measurements, provide
the tightest available constraints of on the antiproton fraction for
energies between 1 and 10 TeV.Comment: 10 pages, 5 figures. Accepted by Physical Review
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
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