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Design and Characterization of a High Vacuum Metals Deposition System based on Electron Beam Evaporation
(2010-08-03)
We describe a high vacuum metals deposition system based ona variation of a pendant-drop type electron beam evaporator.This system uses a Molybdenum crucible as an evaporantinstead of a rod or wire usually used in ultrathin ...
Cooperative elastic fluctuations provide tuning of the metal-insulator transition
(2019)
Metal-to-insulator transitions driven by strong electronic correlations occur frequently in condensed matter systems, and are associated with remarkable collective phenomena in solids, including superconductivity and ...
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 ...
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 ...
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 ...
Dose distribution for CBCT as an aid for radiation protection in dentistry
Distribución de dosis para CBCT como ayuda para la protección radiológica en odontología
(2023)
To characterize effective dose distributions in the craniofacial area for different acquisition parameters
of dental cone beam CT, thermoluminescent dosimeters (TLD) were placed within an anthropomorphic phantom for ...
Validación de Calidades de Rayos X Diagnósticos en el Laboratorio de Metrología de Radiaciones Ionizantes
Quality Validation of Diagnostic X-Ray in the Metrology Laboratory of Ionizing Radiation
(2018)
El objetivo del trabajo fue validar la calidad de radiación para energía de radiodiagnósticos del Laboratorio de Metrología de la Universidad de Costa Rica (UCR) como parte del proyecto técnico de cooperación COS9008 ...
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 ...
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 ...
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 ...