Geometry
Mostrando 1-12 de 2031 artigos, teses e dissertações.
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1. A Defected Ground Structure Based on Matryoshka Geometry
Abstract A Defected Ground Structure, DGS, based on matryoshka geometry is described in this paper. The proposed DGS geometry is outlined and initial design equations are presented. Four prototypes, with resonant frequencies 2.17 GHz, 2.44 GHz, 2.99 GHz and 3.73 GHz, were designed, fabricated and characterized, observing a good agreement between measured and
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. 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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3. A New Miniaturized Low-Profile and Stable Dual-Band FSS with 2.5D Structure for ISM Bands
Abstract Based on 2.5-Dimensional (2.5D) frequency selective surface (FSS) structures, a new miniaturized frequency selective surface structure is proposed in this work to operate as a bandreject filter in the 2.4 GHz (2400 to 2483.5 MHz) and 5 GHz (5150 to 5350 MHz and 5470 to 5725 MHz) ISM (Industrial, Scientific, and Medical) bands. The FSS has the metall
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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4. A Surgical Technique to Preserve the Subvalvular Apparatus in Patients Undergoing Mitral Valve Replacement for Severe Ischemic Regurgitation
ABSTRACT Severe functional mitral valve regurgitation should be treated in patients undergoing myocardial revascularization. When replacement is considered the best therapeutic option, preservation of the mitral subvalvular apparatus is crucial, especially in the emergency setting, because of its primary role in preserving geometry and function of left and r
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
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5. Simulation of Current Pulses and Sound Waves Resulting from Partial Discharges in a Needle-Plane Geometry in Air
Abstract Partial discharges can occur in different types of electric equipment and cause progressive insulation deterioration, so there is interest in monitoring partial discharges for assessing the state of the isolation of an electric system and to predict failures. Techniques to detect partial discharges, such as detecting ultrasonic emission, have been p
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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6. Optimization Techniques and Mathematical Modeling Applied to Reluctance Motors
Abstract The present work aims at the application of different optimization strategies in the electromagnetic analysis of the Variable Reluctance Motor (VRM) through Finite Element (FE) simulation. Two case studies are investigated: the first one aims to optimize the geometry and electrical characteristics of windings of a single-phase VRM 6/6, minimizing co
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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7. Evaluation of the Current in the Cell Membrane for Numerical Simulations of Electroporation
Abstract This study presents a rigorous numerical analysis of the current in the cell membrane, subjected to a uniform electric field, and its impact in the pore formation. The numerical model considers a single cell composed of uniform membrane and cytoplasm, in a suspension medium. The current in the cell membrane is calculated using two different approach
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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8. OBSERVAÇÃO DE HOMODÍMERO DO TIPO BIS-1,3-BENZODIOXONA SINTETIZADO VIA METÁTESE DE OLEFINAS DA PIPERINA CATALISADA POR PRÉ-CATALISADORES DE RU(II) NÃO COMERCIAIS
LN-1 and LN-2 are two Ru(II) complexes coordinated to the phosphine and amines simultaneously, each with two chlorides. PPh3 is the phosphine and the amine is piperidine (LN-1) and perhydroazepine (LN-2). The two compounds are complexes five-coordinated square pyramidal geometry, with the amine in the axial plane. LN-1 and LN-2 were tested for the first time
Química Nova. Publicado em: 2022
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9. Prevalence of chondromalacia patella according to patella type and patellofemoral geometry: a retrospective study
Abstract BACKGROUND: The relationships between the morphometric structure of the patellofemoral joint, patella type and chondromalacia patella are still a matter of debate. OBJECTIVE: To identify the prevalence of chondromalacia patella by determining the patella type and making patellofemoral morphometric measurements. DESIGN AND SETTING: Retrospective c
Sao Paulo Medical Journal. Publicado em: 2022
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10. Preoperative Left Ventricular Global Longitudinal Strain Identifies Aortic Stenosis Patients with Improved Postoperative Recovery of Left Ventricular Geometry: A Prospective Cohort Study
Abstract Introduction: The left ventricular ejection fraction (LVEF) is commonly used as a marker of aortic stenosis (AS) disease severity and to indicate surgical intervention. However, an LVEF <50% identifies mainly advanced disease. Hence, earlier detection of subclinical LV systolic dysfunction may improve clinical decision-making. The global longitudin
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
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11. YIG Matrix Based Multiband Magneto-Dielectric Cylindrical Resonator Antenna
Abstract A multiband magneto-dielectric resonator antenna with cylindrical geometry is proposed in this paper. The resonator is composed of yttrium iron garnet (YIG) with chemical composition Y3Fe2(FeO4)3. The final structure is built on a low-cost FR4 dielectric substrate. With only one resonator, the antenna is able to resonate in three distinct controlled
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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12. Effects of Polycyclic Aromatic Hydrocarbon Pendant-Armed Ligands on the Catecholase Activity of Dinuclear Copper(II) Complexes
Herein, we present three new binuclear copper(II) complexes containing different polycyclic aromatic hydrocarbons, able to catalyze the oxidation of 3,5-di-tert-butylcathecol, a model substrate for catechol oxidase. The ligands and complexes were successful characterized in solid and solution states. The structure of C1 was determined by X-ray crystallograph
J. Braz. Chem. Soc.. Publicado em: 2021-05