Diffusion
Mostrando 1-12 de 5414 artigos, teses e dissertações.
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1. Diffusion-weighted imaging versus non-contrast magnetic resonance imaging in the diagnosis of acute appendicitis during pregnancy
SUMMARY OBJECTIVE: The aim of this study was to evaluate the diagnostic performance of diffusion-weighted imaging compared to non-contrast magnetic resonance imaging in the differential diagnosis of acute appendicitis in pregnant patients. METHODS: A total of 72 pregnant patients with the suspicion of acute appendicitis who underwent magnetic resonance ima
Revista da Associação Médica Brasileira. Publicado em: 2023
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2. Operating Model and Estimation of the Insurance Premium for an Energy Futures Clearing House in Brazil
Abstract Purpose We propose and analyze a new operating model for an energy futures exchange that could be implemented in Brazil, where there is low liquidity for these contracts. The clearing house temporarily assumes the position of customers who fail to answer the margin call, instead of closing the position, as would normally be done under normal condit
Revista Brasileira de Gestão de Negócios. Publicado em: 2023
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3. Role of apparent diffusion coefficient measurement in differentiating histological subtypes of brain metastasis of lung cancer
SUMMARY OBJECTIVE: The aim of this study was to investigate the role of apparent diffusion coefficient of diffusion-weighted imaging in differentiating histological subtypes of brain metastasis of lung cancer. METHODS: Diffusion-weighted imaging of 158 patients (mean age: 61.2±10.68 years) with brain metastasis of lung cancer (36 small cell lung cancer an
Revista da Associação Médica Brasileira. Publicado em: 2022
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4. Variational Formulation and A Priori Estimates for the Galerkin Method for a Fractional Diffusion Equation
ABSTRACT In this work we obtain a variational formulation and a priori estimates for approximate solutions of a problem involving fractional diffusion equations.
Trends in Computational and Applied Mathematics. Publicado em: 2022
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5. 3D Simulation and Artificial Neural Networks Application in the Diffusion Study of Champignon Mushroom/Solution Interface During the Salting
The influence of the film formed during the salting of champignon mushrooms with brine containing NaCl and KCl was modeled using the finite elements method (FEM). It was verified that the film formed on the mushroom surface had a greater influence in the static salting since the diffusion of the ions was 7.5-fold smaller in this system than in the stirred sa
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Anomalous Diffusion with Caputo-Fabrizio Time Derivative: an Inverse Problem
ABSTRACT In this work we identify the source in a 1D anomalous diffusion equation, from measurements of the concentration at a finite number of points. We use Caputo-Fabrizio time fractional derivative to model the phenomenon. Separating variables, we arrive to a linear system which provides approximate values for the Fourier coefficients of the unknown sour
Trends in Computational and Applied Mathematics. Publicado em: 2022
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7. The diffusion of innovations under normative induction in Brazil
Abstract Purpose Hierarchically superior bodies develop normative instructions to induce the diffusion of innovations, stimulating the adoption of management practices in supervised public bodies and seeking public administration efficiency increase. Despite this, the effectiveness of these normative instructions is unknown, as well as its inducing and last
RAUSP Management Journal. Publicado em: 2022
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8. ADSORPTION OF ATRAZINE IN RICE HUSK BIOCHARS: A PHENOMENOLOGICAL MODEL APPLIED TO EQUILIBRIUM AND KINETIC STUDIES
ABSTRACT Atrazine is an herbicide used to remove weeds in agricultural crops; however, because it is considered toxic, options for removing it from the environment are needed. Adsorption on biochar is an efficient technique for removing organic contaminants. In this study, the atrazine adsorption capacities of two biochars (BCA400 and BCA700) produced from r
Engenharia Agrícola. Publicado em: 2022
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9. A Nodal-iterative Technique for Criticality Calculations in Multigroup Neutron Diffusion Models
ABSTRACT In this work, a nodal and iterative technique to evaluate the effective multiplication factor as well as the neutron flux, in multigroup diffusion problems, is presented. An iterative scheme, similar to the source iteration method, is implemented to decouple the system of differential equations which is the fundamental mathematical model. Then, anal
Trends in Computational and Applied Mathematics. Publicado em: 2022
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10. Magnetic resonance and dopamine transporter imaging for the diagnosis of Parkinson´s disease: a narrative review
RESUMO Antecedentes: O diagnóstico da doença de Parkinson (DP) pode ser desafiador, principalmente nas fases iniciais da doença, embora tenha critérios clínicos atualizados e validados. Os avanços recentes em neuroimagem na DP, além do seu papel já consolidado de excluir causas secundárias e outras causas neurodegenerativas de parkinsonismo, tem c
Arquivos de Neuro-Psiquiatria. Publicado em: 2022
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11. Tying the successor’s hands or following the neighbor? Diffusion of access to information in Brazilian municipalities
Resumo Por que os atores políticos promovem a transparência pública? Estudos mostram que a adesão à transparência pode ser tanto politicamente estratégica, ou seja, para atar as mãos do sucessor, quanto resultado da observação da adoção da política feita por outros municípios, isto é, para minimizar o custo da informação. Testamos as motiva�
Revista de Administração Pública. Publicado em: 2022
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12. Comparative evaluation of three classical sizing methods of vibrating screens
Abstract The sizing of vibrating screen machines can be done by various methods, most of them based on the classic method of Allis Chalmers (ACM). Due to the wide diffusion and applicability, the Peter King (PKM) and Karra (KM) methods present great technical relevance as well. The objective of this study was to evaluate and compare the results of the screen
REM - International Engineering Journal. Publicado em: 2022