449 research outputs found
A simple method to estimate the significance level of the catch probability in the catch removal method in riverf ish populations
This work presents a method for estimating the signi®cance level of the capture probability when the capture removal
method is used in riverine ®sh populations. The method is based on adjustment of the linear relationship between capture
probability and an index of capture ef®cacy. With this method the population size, the statistic 2 and the signi®cance level of
the capture probability can be estimated. This is a simple technique which can be applied in the ®eld at the time of sampling. It
does not require the use of computers and can determine in situ whether the catch is valid to calculate the population density
Sensitivity plots for WIMP modulation searches
Prospects of WIMP searches using the annual modulation signature are
discussed on statistical grounds, introducing sensitivity plots for the
WIMP-nucleon scalar cross section.Comment: 3 pages, 2 figures, talk given at TAUP'99, september 199
Specialized business incubators as a strategy for small and medium-sized enterprises in the industry 4.0 era – a systemic approach
The present research aims to get a holistic view of the characteristics of specialization in business incubators models. This paper centers on building a general framework by taking into account a holistic look at the features, profiles, advantages, and disadvantages of specialization in business incubators models. The strategy aims to impact mainly stakeholders by adopting business incubators strategies, especially to those tenant firms of the manufacturing sector related to emerging technologies such as Industry 4.0 technologies. Moreover, the framework is built based on the discussion of the leading representatives' heads of the specialization in the field of specialized business incubators' models. The strategy aims to reduce the current short-term death rate expectancy prevailing in the contemporary
economic context by a robust business model for business incubation. Business incubators hold tenants into a hub with not only supportive facilities for the business without investing vital capital, which is not part of their core chain value but also harnessing the closer source of knowledge transfer and skilfully workforce-related on these technologies. Finally, remarks and recommendations are proposed for futures tenant companies' prospects, who wish to reduce the bankruptcy risk by boosting innovative goods and services with high technological development in a specific field of knowledge.N/
Study of the cosmogenic activation in NaI(Tl) crystals within the ANAIS experiment
The direct detection of galactic dark matter particles requires ultra-low background conditions. NaI(Tl) crystals are applied in the search for these dark matter particles through their interactions in the detector by measuring the scintillation signal produced. The production of long-lived isotopes in materials due to the exposure to cosmic rays on Earth''s surface can be an hazard for these ultra-low background demanding experiments, typically performed underground. Therefore, production rates of cosmogenic isotopes in all the materials present in the experimental set-up, as well as the corresponding cosmic rays exposure history, must be both well-known in order to assess the relevance of this effect in the achievable sensitivity of a given experiment. Here, analysis of the cosmogenic studies developed from the ANAIS experiment NaI(Tl) detectors are presented. Installed inside a convenient shielding at the Canfranc Underground Laboratory just after finishing surface exposure to cosmic rays and thanks to the prompt data taking developed, identification and quantification of isotopes with half-lives of the order of tens of days were allowed, and thanks to the long-term operation of the detectors long-lived isotopes have been also identified and quantified. Main results for the activation yields of iodine and tellurium isotopes, 22Na, 113Sn, 109Cd, and tritium are presented in this work, together with the estimate of the production rates for their activation by cosmic nucleons while on Earth''s surface based on a selection of excitation functions over the entire energy range of cosmic nucleons
Status and preliminary results of the ANAIS experiment at Canfranc
ANAIS (Annual Modulation with NaI's) is an experiment planned to investigate
seasonal modulation effects in the signal of galactic WIMPs using up to 107 kg
of NaI(Tl) in the Canfranc Underground Laboratory (Spain). A prototype using
one single crystal (10.7 kg) is being developed before the installation of the
complete experiment; the first results presented here show an average
background level of 1.2 counts/(keV kg day) from threshold (Ethr~4 keV) up to
10 keV.Comment: 3 pages, 2 figures, talk delivered at the 7th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 2001), September
2001, Laboratori Nazionali del Gran Sasso, Italy (to appear in the Conference
Proceedings, Nucl. Phys. B (Proc. Suppl.)
Cosmogenic and primordial radioisotopes in copper bricks shortly exposed to cosmic rays
Cosmogenic activation is the most common source of radioactivity in copper, being 60 Co the most significant because of its long half-life (5.27 y) and saturation activity at sea level of 1 mBq/kg. Copper bricks, which had been exposed to cosmic rays for 41 days after their casting, were used to replace the internal 10 cm of the lead shielding of a HPGe detector placed at the Canfranc Underground Laboratory. We describe the outcome of the new shielding and the cosmogenic and primordial radioisotopes observed
Sensitivity plots for WIMP direct detection using the annual modulation signature
Annual modulation due to the Earth's motion around the Sun is a well known
signature of the expected WIMP signal induced in a solid state underground
detector. In the present letter we discuss the prospects of this technique on
statistical grounds, introducing annual-modulation sensitivity plots for the
WIMP-nucleon scalar cross section for different materials and experimental
conditions. The highest sensitivity to modulation is found in the WIMP mass
interval 10 GeV< m_W < 130 GeV, the actual upper limit depending from the
choice of the astrophysical parameters, while the lowest values of the
explorable WIMP-nucleon elastic cross-sections fall in most cases within one
order of magnitude of the sensitivities of present direct detection WIMP
searches.Comment: 24 pages, ReVTeX, 9 figures, submitted to Astroparticle Physic
Retos y nuevas perspectivas en la revegetación de sistemas forestales
Entre los días 21 y 23 de noviembre de 2007 tuvo lugar la I Reunión del Grupo de Trabajo de Repoblaciones Forestales de la Sociedad Española de Ciencias Forestales (SECF) y el grupo de trabajo de Restauración Ecológica de la Asociación Española de Ecología Terrestre, y IV Reunión del Grupo de Trabajo de Repoblaciones Forestales de la SECF en las instalaciones del Rectorado de la Universidad de Alcalá. A la reunión asistieron 74 participantes, y se presentaron un total de 39 comunicaciones orales, 18 paneles y 8 ponencias invitadas. Además, se presentó el libro “Calidad de Planta Forestal para la Restauración en Ambientes Mediterráneos” y se organizaron dos mesas redondas, una sobre “Necesidades reales de investigación en calidad de planta y cultivo de planta forestal en vivero” (Tabla 1) y otra sobre “Necesidades reales de la investigación en reforestación” (Tabla 2, 3). Una densa agenda para alcanzar los principales objetivos de la reunión, la presentación de investigación de calidad en el ámbito de la revegetación de sistemas forestales, y el intercambio de experiencias e inquietudes entre los diversos colectivos implicados en la misma. Pero ¿qué imagen podemos extraer del estado actual de nuestros conocimientos en esta área a partir de las comunicaciones presentadas
Status of the ANAIS Dark Matter Project at the Canfranc Underground Laboratory
The ANAIS (Annual modulation with Nal(Tl) Scintillators) experiment aims at the confirmation of the DAMA/LIBRA signal using the same target and technique at the Canfranc Underground Laboratory (LSC). Along 2016, 112.5 kg of ultra pure Nal(Tl) crystals will be installed at LSC in a 3×3 modules matrix configuration. The ANAIS-25 and ANAIS-37 set-ups have been taking data at the LSC testing the detector performance, the DAQ and analysis systems, and assessing the background. Main results coming from both set-ups will be summarized in this paper, focusing on the excellent detector performance and background understanding. Prospects for the experiment will be also briefly revised
Background study for the pn-CCD detector of CERN Axion Solar Telescope
The CERN Axion Solar Telescope (CAST) experiment searches for axions from the
Sun converted into photons with energies up to around 10 keV via the inverse
Primakoff effect in the high magnetic field of a superconducting Large Hadron
Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in
conjunction with an X-ray mirror optics is one of the three detectors used in
CAST to register the expected photon signal. Since this signal is very rare and
different background components (environmental gamma radiation, cosmic rays,
intrinsic radioactive impurities in the set-up, ...) entangle it, a detailed
study of the detector background has been undertaken with the aim to understand
and further reduce the background level of the detector. The analysis is based
on measured data taken during the Phase I of CAST and on Monte Carlo
simulations of different background components. This study will show that the
observed background level (at a rate of (8.00+-0.07)10^-5 counts/cm^2/s/keV
between 1 and 7 keV) seems to be dominated by the external gamma background due
to usual activities at the experimental site, while radioactive impurities in
the detector itself and cosmic neutrons could make just smaller contribution.Comment: Comments: 10 pages, 9 figures and images, submitted to Astroparticle
Physic
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