Search results for "source"
showing 10 items of 6139 documents
Search for Extraterrestrial Point Sources of Neutrinos with AMANDA-II
2003
We present the results of a search for point sources of high energy neutrinos in the northern hemisphere using AMANDA-II data collected in the year 2000. Included are flux limits on several AGN blazars, microquasars, magnetars and other candidate neutrino sources. A search for excesses above a random background of cosmic-ray-induced atmospheric neutrinos and misreconstructed downgoing cosmic-ray muons reveals no statistically significant neutrino point sources. We show that AMANDA-II has achieved the sensitivity required to probe known TeV gamma-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and gamma-ray fluxes are equal.
Latvija. Pārskats par tautas attīstību 2006/2007 : Cilvēkkapiltāls: mans zelts ir mana tauta?
2007
Latvija. Pārskats par tautas attīstību 2006/2007 : Cilvēkkapiltāls: mans zelts ir mana tauta?. Rīga : LU Sociālo un politisko pētījumu institūts, 2007. 117 lpp.
Search for neutrino emission from gamma-ray flaring blazars with the ANTARES telescope
2012
The ANTARES telescope observes a full hemisphere of the sky all the time with a duty cycle close to 100%. This makes it well suited for an extensive observation of neutrinos produced in astrophysical transient sources. In the surrounding medium of blazars, i.e. active galactic nuclei with their jets pointing almost directly towards the observer, neutrinos may be produced together with gamma-rays by hadronic interactions, so a strong correlation between neutrinos and gamma-rays emissions is expected. The time variability information of the studied source can be obtained by the gamma-ray light curves measured by the LAT instrument on-board the Fermi satellite. If the expected neutrino flux ob…
Sound conversion phenomena at the free surface of liquid helium. I. Calculation of the coefficients of reflection, transmission, and transformation o…
1980
On the basis of a set of boundary conditions describing quite generally mass and energy transport processes across the free surface of helium II, the acoustic coefficients of reflection, transmission, and transformation of first sound, second sound, and the sound wave propagating in the vapor are calculated in the case of perpendicular incidence of sound waves against the liquid-vapor phase boundary. Considering rigorously the influences of the Onsager surface coefficients, the isobaric thermal expansion coefficients, and the thermal conductivities of the liquid and the vapor, we derive sets of equations from which the acoustic coefficients are determined numerically. For estimations, simpl…
Absorptive Capacity and Social Capital: Innovation and Environmental Regulation
2010
Norwegian paper and pulp mills are subject to strict environmental regulation. The mills conduct research and development for reducing pollution. Absorptive capacity indicates their competence. Firms are part of a social network of connections with external actors that include other paper and pulp mills, suppliers, customers, research institutes, and universities that help them in developing technologies. These relations represent their social capital. Some firms have access to more and better resources than other firms. Measuring firms’ absorptive capacity and access to social capital, we analyze their success in reducing pollution levels. There is a strong interaction effect between absor…
The need to grow, learn and develop – how does management affect motivation for professional development?
2018
This article argues that knowledge management and social recognition is important for organisational learning and professional self-esteem in academic libraries. An anonymous survey was issued in 2016 to investigate how library staff’s self-esteem is affected by how they experience their management’s view and overview of their knowledge. The need for what Axel Honneth refers to as social recognition will also be discussed as an important part of how professional self-esteem and work satisfaction is experienced and further how this affects motivation to participate in professional development.
Digital resources in senegalese hight education : state of play and prospective study
2014
It is in the context of poverty or information exclusion that the massive dissemination of information and technology tools in Senegalese academic libraries responds to an urgent need for transformation and improvement of operational modes as well as modernization of services for different audiences, in particular students. Currently, in almost all academic and research libraries of Senegal digitization activities that crossed the rise of the Internet are being developed. This has created a real increasing effect of digital resources, by the establishment of means of creation and by expansion of access and of sharing of scientific and technical information in higher education institutions. …
The Necessary Competences for Student Success in the First Academic Year
2013
En ligne sur : http://infonomics-society.org/IJCDSE/The%20Necessary%20Competences%20for%20Student%20Success%20in%20the%20First%20Academic%20Year.pdf; International audience; This paper tries to show which competences have an impact on the success of students in higher education and especially in the first academic year. This situation also requires finding a way to acquire the competences which are necessary in this new experience that is the first year. A student is considered to be a person who has the basic competences required. Our role is to show how this person in higher education can acquire the other new competences that help him/her attain the positive results that we name ''succes…
New exotic beams from the SPIRAL 1 upgrade
2018
Since 2001, the SPIRAL 1 facility has been one of the pioneering facilities in ISOL techniques for reaccelerating radioactive ion beams: the fragmentation of the heavy ion beams of GANIL on graphite targets and subsequent ionization in the Nanogan ECR ion source has permitted to deliver beams of gaseous elements (He, N, O, F, Ne, Ar, Kr) to numerous experiments. Thanks to the CIME cyclotron, energies up to 20 AMeV could be obtained. In 2014, the facility was stopped to undertake a major upgrade, with the aim to extend the production capabilities of SPIRAL 1 to a number of new elements. This upgrade, which is presently under commissioning, consists in the integration of an ECR booster in the…
Design of a 10 GHz minimum-B quadrupole permanent magnet electron cyclotron resonance ion source
2020
This paper presents a simulation study of a permanent magnet electron cyclotron resonance ion source (ECRIS) with a minimum-B quadrupole magnetic field topology. The magnetic field is made to conform to conventional ECRIS with $B_\textrm{min}/B_\textrm{ECR}$ of 0.67 and a last closed magnetic isosurface of 1.86$B_\textrm{ECR}$ at 10 GHz. The distribution of magnetic field gradients parallel to the field, affecting the electron heating efficiency, cover a range from 0 to 13 T/m, being similar to conventional ECRIS. Therefore it is expected that the novel ion source produces warm electrons and high charge state ions in significant number. Single electron tracking simulations are used to estim…