Listar Física por título
Mostrando ítems 91-110 de 113
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Search for gamma-ray emission from star-forming galaxies with Fermi LAT
(2016-08)Recent studies have found a positive correlation between the star-formation rate of galaxies and their gamma-ray luminosity. Galaxies with a high star-formation rate are expected to produce a large amount of high-energy ... -
Sesión "Medicina nuclear"
(2017-01)En la sesión dedicada a la Medicina Nuclear (MN) se identificaron los cinco aspectos que se consideran más problemáticos en la protección radiológica en MN. Estos hacen referencia a: 1. Garantizar que la dosis administrada ... -
Short term topological changes of coronal holes associated with prominence eruptions and subsequent CMEs
(2013-03-15)We study the short-term topological changes of equatorial and polar coronal hole (CH) boundaries, such as a variation of their area and disintegration, associated to reconnection with nearby (within 15° distance) quiescent ... -
Stochastic approach to the smart quantum confinement model in porous silicon
(Surface Science 515 (2002) L509-L513, 2002)A model that encompasses two approaches to explain the photoluminescence in p-type porous silicon is proposed. The model considers a stochastic distribution of nanocrystallite sizes within the porous matrix and explain the ... -
Structure factor of a relaxor ferroelectric
(2015-04-14)We study a minimal model for a relaxor ferroelectric including dipolar interactions, and short-range harmonic and anharmonic forces for the critical modes as in the theory of pure ferroelectrics together with quenched ... -
Study of oxide bands in p-type porous silicon layers
(2019)The interest in developing fast and reliable chemical and biochemical sensors in an inexpensive way is something that has attracted a lot of efforts in the last decades. One of the potential material candidates is ... -
The 2:3:6 quasi-periodic oscillation structure in GRS 1915+105 and cubic subharmonics in the context of relativistic discoseismology
(Monthly Notices of the Royal Astronomical Society 440:3011-3015, 2014-06-01)We propose a simple toy model to explain the 2:3:6 quasi-periodic oscillation (QPO) structure in GRS 1915+105 and, more generally, the 2:3 QPO structure in XTE J1550−564, GRO J1655−40 and H1743−322. The model exploits the ... -
The early rainy season in Central America: the role of thetropical North Atlantic SSTs
(2016)We explored the relationship between the precipitation anomalies during May to June as the first peak of the rainy season in the Pacific slope of Central America, and sea surface temperature (SST) fluctuations in the ... -
The gigaelectronvolt counterpart of ver j2019+407 in the northern shell of the supernova remnant g78.2+2.1 (γ cygni)
(2016-07)Analysis of gamma-ray emission from the supernova remnant G78.2+2.1 (γ Cygni) with 7.2 years of cumulative data from the Fermi Large Area Telescope shows a distinct hard, bright, and extended component to the north of the ... -
The High-Altitude water cherenkov (HAWC) observatory in México: The primary detector
(2023-07)The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the ... -
The Hubble Constant and the Deceleration Parameter in Anisotropic Cosmological Spaces of Petrov type D
(2016-11)In this paper the Hubble parameter and the deceleration parameter are analyzed for a group of anisotropic homogeneous solutions of the Petrov type-D. It is obtained that for the said set of solutions can be constructed a ... -
The Josephson junction as a quantum engine
(2023-11-10)We treat the Cooper pairs in the superconducting electrodes of a Josephson junction (JJ) as an open system, coupled via Andreev scattering to external baths of electrons. The disequilibrium between the baths generates the ... -
The mechanical career of Councillor Orffyreus, confidence man
(2013-05)In the early 18th century, J. E. E. Bessler, known as Orffyreus, constructed several wheels that he claimed could keep turning forever, powered only by gravity. He never revealed the details of his invention, but he ... -
The problem of engines in statistical physics
(2021-08-22)Engines are open systems that can generate work cyclically at the expense of an external disequilibrium. They are ubiquitous in nature and technology, but the course of mathematical physics over the last 300 years has ... -
Tropical easterly waves over Costa Rica and their relationship to the diurnal cycle of rainfall
(2023-01)Using an index of tropical easterly wave (TEW) activity derived from spacetime-filtered outgoing longwave radiation, we construct composites of long-term hourly surface meteorological observations and morningtime sounding ... -
Tropical precipitation anomalies and d‐excess evolution during El Niño 2014‐16
(2016)The last 2014-16 El Niño event was among the three strongest episodes on record. El Niño considerably changes annual and seasonal precipitation across the tropics. Here, we present a unique stable isotope data set of daily ... -
Tsunamis and Tsunami Hazards in Central America
(2000-02)A tsunami catalogue for Central America is compiled containing 49 tsunamis for the period 1539–1996, thirty seven of them are in the Pacific and twelve in the Caribbean. At the Caribbean side, 5 events are related with ... -
Tsunamis and tsunami prepardness in Costa Rica, Central America
(2005-12)Pacific and Atlantic sides of Costa Rica there are coastal segments characterised by a flat relief, which increases the vulnerability of the coastal communities. In addition to tsunamis originating in the Middle American ... -
Vacuum treatment to stabilize oxidation at low temperature region in porous silicon
(2020)Oxidation in porous silicon is studied for as-etched samples and samples subjected to high vacuum at room temperature. Attenuated Total Reflectance (ATR) measurements in infrared spectroscopy for temperatures ranging from ...