Linear Stability
Mostrando 1-12 de 565 artigos, teses e dissertações.
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1. Unplanned dilution back analysis in an underground mine using numerical models
Abstract In underground mines, stability problems can cause unplanned dilution, increasing the costs of mining operations, such as loading, transport, crushing and grinding. This is usually dealt with by simply increasing investments with support. However, the design geometry of stopes and drifts also has a great effect on a stope’s stability. The use of e
REM - International Engineering Journal. Publicado em: 2022
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2. Numerical Analysis and Approximate Travelling Wave Solutions for a Higher Order Internal Wave System
ABSTRACT In this work we focus on the numerical solution of a higher order bidirectional nonlinear model of Boussinesq type involving a nonlocal operator. Based on a von Neumann stability analysis for the linearized problem, an efficient and stable scheme for the nonlinear system is proposed. Our method is based on a numerical scheme known from the literatur
Trends in Computational and Applied Mathematics. Publicado em: 2022
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3. Quality Control for Lignin and Gelatin Microcapsules Loaded with Orange Essential Oil
Sustainable natural product-based microstructured systems and biopolymers are strong candidates for use in crop protection. Lignin and gelatin microcapsules loaded with orange essential oil were developed with spray-drying in order to enhance its potential. We evaluated the microparticle controlled release mechanisms, biological effects, structural and therm
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Spectrofluorimetric Determination of Hydrochlorothiazide by a Carbon Dots-Based Probe via Inner Filtering Effect and Resonance Rayleigh Scattering
Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Changes in the rest-activity rhythm in migraine patients are associated with anxiety symptoms
Objective: To characterize rest-activity rhythm in chronic migraine (CM) and to investigate the relationship between this rhythm and depressive and anxiety symptoms in patients with CM. Methods: This was a study of adults aged 20 to 40 years. The rest-activity rhythm of patients with CM (n=23) and non-headache controls (NH, n=23) was assessed by actigraphy
Brazilian Journal of Psychiatry. Publicado em: 2022
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6. Relationship between depressive symptoms, burnout, job satisfaction and patient safety culture among workers at a university hospital in the Brazilian Amazon region: cross-sectional study with structural equation modeling
ABSTRACT BACKGROUND: Workplaces can be sources of mental distress. In healthcare services, this can also affect patients. OBJECTIVE: To assess the prevalence of and factors associated with depressive symptoms, burnout, job satisfaction and patient safety culture and the relationships between these constructs, among healthcare workers. DESIGN AND SETTING:
Sao Paulo Medical Journal. Publicado em: 2022
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7. Reduced Graphene Oxide/Ruthenium Oxide Hexacyanoferrate Nanocomposite for Electrochemical Determination of Ethanol in Commercial Samples
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
J. Braz. Chem. Soc.. Publicado em: 2021-06
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8. Individuals with untreated psychiatric disorders and suicide in the COVID-19 era
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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9. Increased depression and anxiety during the COVID-19 pandemic in Brazilian mothers: a longitudinal study
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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10. Development and Validation of a Gas Chromatographic Method for the Quantification of Minor Alkaloids in Cocaine
The quantification of minor alkaloids in seized cocaine can provide information for drug profiling and law enforcement initiatives. This work presents the development and validation of an analytical method to quantitate minor alkaloids in cocaine samples using gas chromatography with flame ionization detector, after derivatization. The method was validated i
J. Braz. Chem. Soc.. Publicado em: 2021-04
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11. THEORETICAL INVESTIGATIONS ON DETONATION PERFORMANCE AND STABILITY OF THE DIFLUOROAMINO-PRISMANE DERIVATIVES
The difluoroamino derivatives of prismane were designed and calculated at the B3LYP/6-311G** level. The detonation performances, as well as the band gap, were investigated to look for high energy density compounds. Our calculations showed that difluoroamino group is an effective substitute group for increasing density and heats of formation. All compounds ha
Quím. Nova. Publicado em: 2021-02
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12. ERRATA
ABSTRACT BACKGROUND: Cancer is a serious public issue problem worldwide. In Brazil, breast cancer is the most common type and cervical cancer is the third most frequent among women. OBJECTIVE: To analyze the temporal trend of coverage of mammography and cervical oncotic cytological testing, between 2007 and 2018. DESIGN AND SETTING: Time-series study cond
Cad. Metrop.. Publicado em: 2020-12