Collision Frequency
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Arsenic and Other Elements Determination in Seawater Using Coprecipitation and Standard Mode Inductively Coupled Plasma Mass Spectrometry
The present work aims the determination of As, Co, Cr, Cu, Mn and Pb in seawater samples using coprecipitation extraction procedure before standard mode inductively coupled plasma mass spectrometry (ICP-MS) (no collision/reaction cell). The coprecipitation procedure is based on the precipitation of Mg(OH)2 from the reaction of the Mg2+ ions (present into the
J. Braz. Chem. Soc.. Publicado em: 2021-01
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2. Determination of Selenium in Bovine Semen by ICP-MS Using Formic Acid for Sample Preparation
Determination of Se by inductively coupled plasma mass spectrometry (ICP-MS) can be difficult due to spectral interferences; however, these interferences can be eliminated by using collision-reaction interface (CRI) technology. A simple and fast procedure for determination of total Se concentration in bovine semen by ICP-MS after sample solubilization with d
J. Braz. Chem. Soc.. Publicado em: 2017-12
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3. Relationship between bird-of-prey decals and bird-window collisions on a Brazilian university campus
ABSTRACT Bird-window collisions are a dramatic cause of bird mortality globally. In Latin America, statistics are generally very scarce and/or inaccessible so the frequency of such incidents is still poorly understood. Nevertheless, civilians have applied preventive methods (e.g. adhesive bird-of-prey decals) sparsely but, to our knowledge, no study has eval
Zoologia (Curitiba). Publicado em: 19/10/2017
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4. Simulation and manufacturing of a miniaturized exponential UWB TEM horn antenna for UWB radar applications
This paper presents the parameterization of the structure of a miniaturized exponential UWB TEM horn antenna and its effect on the matching impedance and directivity. In addition, a microstrip balun that feeds the antenna was proposed in order to improve the balance, and the return loss for low frequencies. Both the antenna and the microstrip balun were simu
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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5. Ondas gravitacionais e o espectro de anisotropia tensorial na presença de neutrinos cosmológicos
In this work we have studied the evolution of primordial gravitational waves coupled to anisotropic stress tensor of cosmological neutrinos. As in a radiation dominated universe, in a universe dominated by radiation and matter the neutrinos can work as an effective dispersive medium for the gravitational waves, besides introduce small modifications over the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/07/2012
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6. Padrões espacial e temporal do atropelamento de mamíferos em uma rodovia no cerrado brasileiro
This thesis is divided into a general introduction on the issue of roads ecology and the main factors that lead to the general public and the animals roadkills, followed by a chapter that investigates if there is spatial and seasonal patterns of medium and big mammals roadkills in a road (SP-225) in northeast of São Paulo State, Brazil. The road is located
Publicado em: 2011
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7. Characterization of traveling ionospheric disturbances over low latitude brazilian region associated to Perkins plasma instability generated at medium latitudes / Caracterização de distúrbios ionosféricos propagantes na região de baixas latitudes no setor brasileiro associados à instabilidade de plasma Perkins gerada em médias latitudes
With ground based measurements of OI 630 nm emission, by using all-sky imaging system installed at Cachoeira Paulista, we investigated the occurrence of specific events of Medium Scale Traveling Ionospheric Disturbances (MSTIDs), which occurred during nights geomagnetically quiet. Probably, these disturbances are associated with Perkins plasma instability ge
Publicado em: 2010
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8. DETERMINATION OF TOTAL AS IN OCEANIC WATER BY HG AFS / DETERMINAÇÃO DE AS TOTAL EM ÁGUAS OCEÂNICAS POR HG AFS
The increase in industrial activity has increased human exposure to metals and metalloids exponentially. In this context, arsenium is a good example, being increasingly found in several natural environments. It is an element with no essential biological function, and possessed of elevated toxicity. The discharge of toxic elements in aquatic bodies can promot
Publicado em: 2010
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9. Photoassociative ionization in situations with low dimensions / Investigação do processo de foto-ionização associativa em situações com baixa dimensão
Photoassociative ionization (PAI) in a cold sample of sodium atoms was the main subject of our studies as a way to understand the effects of repulsive states and collision dimensions. Two-color PAI experiment were preformed in a magneto-optical trap (MOT) trough the addition of a probe laser beam, the intensity, polarization and frequency of that probe laser
Publicado em: 2009
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10. Structural health monitoring of composite materials subjected to impacts using the electromechanical impedance technique / Monitoramento de integridade estrutural de materiais compostos sujeitos a impactos empregando a técnica da impedância eletromecânica
Nowadays, composite materials have increasingly replaced traditional materials in applications that require improved performance, safety, economy and durability. Nonetheless, such materials exhibit complex damage mechanisms that cannot be easily detected in early stages. Failures can occur during manufacturing, operation or even in the course of maintenance.
Publicado em: 2008
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11. W.K.B. Solutions for the Calculation of Field Intensity in the lower Ionosphere / Soluções W.K.B. para o cálculo da intensidade de campo na baixa ionosfera
Este trabalho apresenta métodos de cálculo aproximado do campo de uma onda se propagando na ionosfera. A ionosfera é um dos meios mais complexos quando se deseja calcular a intensidade de campo de uma onda eletromagnética, porque ela possui uma densidade eletrônica que varia com as estações do ano, e principalmente com a hora do dia. Outra dificuldade
Publicado em: 2007
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12. Comparative study of vibracional excitation of hydrogen molecules by electron and positron impact / Estudo comparativo das seções de choque de excitações vibracionais de moleculas de hidrogenio por impacto de positrons e eletrons
Here we report a comparative calculation of both integral and differential vibrational excitation cross sections of low energy positron and electron scattering against Hydrogen molecules (H2). For these calculations we have used the Schwinger Multichannel (SMC) Method [1] for positron collision [2] and electron collision [3]. Using a set of SMC scattering am
Publicado em: 2006