3,904 research outputs found

    Higher Education ‘Market’ in Portugal: a diagnosis

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    The higher education system in Portugal, in recent decades, experienced profound structural changes, including a substantial increase in the number of higher education institutions, scattered throughout the country, with a growing number of students and teachers. The subject of this study is to examine the characteristics of current supply and demand within the higher education subsystem, in Portugal. The methodological approach includes two steps: first, making a characterization of key variables that shape demand and supply of higher education in Portugal and, second, using spatial econometric analysis, particularly multidimensional scaling, in order to estimate the location of universities.Higher education, Multidimensional scaling, Spatial location.

    Construction of a non-standard quantum field theory through a generalized Heisenberg algebra

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    We construct a Heisenberg-like algebra for the one dimensional quantum free Klein-Gordon equation defined on the interval of the real line of length LL. Using the realization of the ladder operators of this type Heisenberg algebra in terms of physical operators we build a 3+1 dimensional free quantum field theory based on this algebra. We introduce fields written in terms of the ladder operators of this type Heisenberg algebra and a free quantum Hamiltonian in terms of these fields. The mass spectrum of the physical excitations of this quantum field theory are given by n2π2/L2+mq2\sqrt{n^2 \pi^2/L^2+m_q^2}, where n=1,2,...n= 1,2,... denotes the level of the particle with mass mqm_q in an infinite square-well potential of width LL.Comment: Latex, 16 page

    Searching for emission-line galaxies: The UCM survey

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    We are carrying out a long-term project with the main purposes of finding and analyzing low metallicity galaxies. A very small number of very low metallicity galaxies is known up to now. However these ojbects are particularly interesting since they are excellent candidates to 'young galaxies' in evolutionary sense as POX186 (Kunth, Maurogordato & Vigroux, 1988). Since the interstellar matter in these objects is only weakly contaminated by stellar evolution, their study could provide valuable information about the primordial helium abundance and therefore it could place constraints on the different Big-Bang models. The instrumental set up of our survey is an objective-prism used with the Schmidt telescope at Calar Alto Observatory. By using hypersensitized IIIaF emulsion and RG630 filter low resolution spectra in the H alpha region of objects in a wide field is obtained (Rego et al. 1989, Zamorano et al. 1990). Surveys carried out in the past two decades at optical blue wavelengths have also produced large samples of emission-line galaxies (ELGs), for example MacAlpine & Willians 1981 and reference therein, Wasilewski 1983, Salzer and MacAlpine 1988, or Smith et al. 1976. Relying primarily on objective-prism plates taken in the blue, these surveys have found over 3000 blue/emission-line galaxies so far. A significant number of star-forming galaxies are missed by optical surveys in the blue because of their low-excitation spectra (MacAlpine and Willians 1981, Markarian et al. 1981 and references therein) or their low metallicity (Kunth and Sargent, 1986)

    Alien Registration- Rego, Marguerite M. (Portland, Cumberland County)

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    https://digitalmaine.com/alien_docs/25464/thumbnail.jp

    Some boundary effects in quantum field theory

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    We have constructed a quantum field theory in a finite box, with periodic boundary conditions, using the hypothesis that particles living in a finite box are created and/or annihilated by the creation and/or annihilation operators, respectively, of a quantum harmonic oscillator on a circle. An expression for the effective coupling constant is obtained showing explicitly its dependence on the dimension of the box.Comment: 12 pages, Late
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