Browsing Exact and Earth Sciences by Title
Now showing items 5948-5967 of 6198
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UAVouch : a secure identity and location validation scheme for UAV-networks
(2021) [Journal article]Emerging surveillance applications of UAV teams rely on secure communication to exchange information, coordinate their movements, and fulfill mission objectives. Protecting the network by identifying malicious nodes that ... -
A UFO Seen Edge-on? : resolving Ultrafast Outflow Emission on ∼200 pc Scales with Chandra in the Active Nucleus of Mrk 34
(2023) [Journal article]We present Chandra ACIS imaging spectroscopy of the nucleus of the Seyfert 2 Galaxy Mrk 34. We identify spatially and spectrally resolved features in the band that includes Fe Kα, Fe xxv, and Fe xxvi. These features suggest ... -
UHMWPE-layered silicate nanocomposites by in situ polymerization with tris(pyrazolyl)borate titanium/clay catalyst
(2009) [Journal article]Nanocompósitos de polietileno-MMT foram preparados através da metodologia de polimerização in situ utilizando TpMs*TiCl3 (1) intercalado na galeria da Cloisite 30B (C30B) e na presença de metilaluminoxano (MAO) como ... -
Ultrafast trapping times in ion implanted InP
(2002) [Journal article]As+ and P+ implantation was performed on semi-insulating (SI) and p-type InP samples for the purpose of creating a material suitable for ultrafast optoelectronic applications. SI InP samples were implanted with a dose of ... -
Ultralight energy neutrinos and nonlinear QCD dynamics
(2004) [Journal article]The ultrahigh energy neutrino-nucleon cross sections are computed taking into account different phenomenological implementations of the nonlinear QCD dynamics. Based on the color dipole framework, the results for the ... -
Ultrastable phonon frequencies in α-quartz-type BPO4 at high temperature
(2019) [Journal article]The Raman modes of α-quartz-type boron phosphate were found to be extremely stable in frequency over a large temperature range from 300–1000 K. In order to determine the origin of this behavior, the material was also studied ... -
Ultrathin silicon oxynitride film formation by plasma immersion nitrogen implantation
(1999) [Journal article]A method is proposed to prepare ultrathin silicon oxynitride films for gate dielectrics used in deep submicron metal–oxide–semiconductor field effect transistor device structures, namely plasma immersion N implantation ... -
Ultraviolet spectral properties of magellanic and non-magellanic irregulars, H II and Starburst galaxies
(1999) [Journal article]This paper presents the results of a stellar population analysis performed on nearby (VR ≤ 5 000 kms-ˡ) starforming galaxies, comprising magellanic and non-magellanic irregulars, H II and starburst galaxies observed with ... -
Ultraviolet to near-infrared spectral distributions of star-forming and Seyfert 2 galaxies
(1995) [Journal article]Combined UV, optical, and near-IR spectral distributions of a sample of 48 southern star-forming and Seyfert 2 galaxies are presented. The optical and near-IR spectra were obtained using apertures matching those ofthe UV ... -
Ultraviolet to near-infrared spectral distributions of star-forming galaxies : metallicity and age effects
(1994) [Journal article]Spectral distributions from the UV to the near-IR of a sample of 44 star-forming galaxies are used to calculate the metallicity (0/H), star-formation rate (SFR) and age of the starbursts. The oxygen abundance covers the ... -
Una aproximación congnitiva al aprendizaje del concepto "célula" : un estudio de caso
(2003) [Journal article]Se realiza una interpretación de las respuestas emitidas por un alumno relativas al concepto célula, con objeto de determinar su modo de operar con el mismo y de pensarla. Para dicho análisis se usan dos teorías como ... -
Una interpretación aproximativa del concepto de hidrólisis en estructuras peptídicas en un curso de bioquímica del IPC en el contexto de la teoría de los campos conceptuales de Vergnaud
(2008) [Journal article]Este trabajo cualitativo-descriptivo tuvo como propósito identificar invariantes operatorios en esquemas activados por los estudiantes en la aplicación teórica del concepto de hidrólisis a péptidos. Se usaron algunas ... -
Una interpretación de las opiniones de ingresantes a al universidad a la universidad sobre la noción de interacción
(2004) [Journal article]Este trabajo detalla el proceso realizado para analizar las respuestas a un test, distribuido entre aspirantes a ingresar en la Facultad de Ciencias Exactas de la Universidad Nacional del Centro, en Tandil, Buenos Aires. ... -
Una revisión de literatura sobre el uso de modelación y simulación computacional para la enseñanza de la física en la educación básica y media
(2016) [Journal article]Este art´ıculo presenta una revisi´on de la literatura que aborda los principales referentes epistemol´ogicos, psico-pedag´ogicos y did´acticos en las investigaciones sobre actividades de Modelaci´on y Simulaci´on Computacional ... -
Una visión toulminiana respecto a la disciplina investigación básica en educación en ciencias : el rol del foro institucional
(2005) [Journal article]El objectivo de esta presentación es el argumentar que el área de investigación en educación en ciencias ha alcanzado un nivel de desarrollo que ya puede ser considerada una disciplina según los criterios de Stephen Toulmin. ... -
O Unbral Fronteiras em busca de boas práticas na divulgação e preservação da produção acadêmica
(2015) [Journal article] -
Unconventional singlet-triplet superconductivity
(2022) [Journal article]Have you been lying awake wondering what symmetries determine whether a superconductor is spin-singlet, triplet, or both? We show that if one supplies additional degrees of freedom to BCS theory, spin-singlet can coexist ... -
Unconventional superconducting granularity of the Y/sub 1-x/Pr/sub x/Ba/sub 2/Cu/sub 3/O/sub 7-[delta]/ compound
(2006) [Journal article]We report on fluctuation magnetoconductivity and magnetic irreversibility of Y1−xPrxBa2Cu3O7− single crystals and a polycrystalline sample. Although our samples are all single phase orthorhombic and the single crystals ... -
Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4
(2022) [Journal article]Pulsating low-mass white dwarf (WD) stars are WDs with stellar masses between 0.30 and 0.45 M⊙ that show photometric variability due to gravity-mode pulsations. Within this mass range, they can harbour both a helium core ... -
Underlying-event properties in pp and p–Pb collisions at √sNN = 5.02 TeV
(2023) [Journal article]We report about the properties of the underlying event measured with ALICE at the LHC in pp and p–Pb collisions at √ sNN = 5.02 TeV. The event activity, quantified by charged-particle number and summed-pT densities, is ...
