Tuning
Mostrando 1-12 de 498 artigos, teses e dissertações.
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1. Single Port Multimode Reconfigurable UWB-NB Antenna for Cognitive Radio Applications
Abstract In this paper, a compact, single port, multimode reconfigurable UWB-NB antenna with a novel feeding network is presented. The proposed antenna consists of a pentagonal-shaped monopole radiator, a beveled-shaped partial defected ground plane with a rectangular slot, and a reconfigurable bypass feeding network. The antenna realizes a wideband frequenc
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Tuning the Photocatalytic Activity of Tin Oxide through Mechanical Surface Activation
Tin oxide (SnO2) nanoparticles were synthesized by the co-precipitation method and mechanically modified by high-energy ball milling. The experimental results demonstrate that the collision with zirconia balls produces slight changes in the crystalline, electronic, morphological, and surface properties of SnO2, which lead to an increase in the redox potentia
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. A Greener Enzymatic Oligoesterification of Biobased Renewable Synthons
Polyesters of xylitol and succinic acid were prepared yielding from 70 to 75% by enzyme-catalyzed esterification using a molar mass from 1:1 to 2:5 at 120 and 140 °C employing from 1 to 10% m/m of enzyme. Control over branching degree was achieved by tuning the reaction conditions (temperature, time, comonomer ratio, enzyme content). This one-step process f
J. Braz. Chem. Soc.. Publicado em: 2021-06
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4. Desenvolvimento de software e interface para o controle por retroalimentação atrasada em sistemas eletroquímicos
In this paper, we show the development of a LabVIEW algorithm able to apply the delayed feedback control on oscillatory electrochemical reactions. The coupling of the control and the experiments was carried out by a real-time apparatus, measuring the faradaic current and, in sequence, applying a calculated circuit voltage as an analog output. The setup was u
Quím. Nova. Publicado em: 2021-06
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5. Astaxanthin Recovery from Shrimp Residue by Solvent Ethanol Extraction Using Choline Chloride:Glycerol Deep Eutectic Solvent as Adjuvant
The present study investigated the use of choline chloride:glycerol deep eutectic solvent as an adjuvant for tuning the ethanol extraction of astaxanthin from Litopenaeus vannamei processing residues. The adjuvant concentration did not show a clear trend on the total carotenoid, however, the addition of adjuvant proved to be advantageous in the ultrasound-as
J. Braz. Chem. Soc.. Publicado em: 2021-05
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6. Photoluminescent Investigation of the Doping Site of Eu3+-Doped [Zn3(BTC)2·12H2O] Metal-Organic Framework Prepared by Microwave-Assisted Hydrothermal Synthesis
The [Zn3(BTC)2·12H2O] (BTC = 1,3,5-tricarboxylate) metal-organic framework (MOF) was successfully synthesized using a microwave-assisted hydrothermal synthesis technique, which allowed for significantly decreased reaction time compared to the production of the same compound via conventional heating. In situ doping with Eu3+ ions at concentrations ranging fr
J. Braz. Chem. Soc.. Publicado em: 2020-11
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7. Discrete element modeling of non-spherical particles using a spherical shape
Abstract Real non-spherical particles can be modeled using the Discrete Element Method (DEM) with sphere clusters, superquadrics, or polyhedral particles. However, in applications involving a considerable number of particles, the analysis can become impracticable. The goal of this study is to demonstrate how well spherical particles can reproduce the flow of
REM, Int. Eng. J.. Publicado em: 2020-09
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8. DESIGN OF ELECTRONIC CONTROL GOVERNOR FOR A SINGLE CYLINDER GASOLINE ENGINE BASED ON AN INTELLIGENT SENSING ALGORITHM
ABSTRACT At present, most large machinery and vehicle engines are electronically controlled but their electronic control systems are too expensive to be popularised and applied in small gasoline engines with relatively low prices. Therefore, small gasoline engines still use mechanical speed regulators. Mechanical speed regulators not only have the defects of
Eng. Agríc.. Publicado em: 2020-08
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9. INTEGRATING REAL TIME OPTIMIZATION AND MODEL PREDICTIVE CONTROL OF A CRUDE DISTILLATION UNIT
Abstract This work reports the integration of Real Time Optimization and Model Predictive Control in the multi-layer control structure of an existing Crude Distillation Unit (CDU) of an oil refinery. The MPC considers output control zones and targets for the inputs or outputs. Both the infinite horizon and the finite output horizon controllers were tested. T
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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10. Inflammation: friend or foe of bovine reproduction?
Abstract Inflammation is not only the first line of defense of the organism but is also required in many reproductive processes such as ovulation, corpus luteum development, luteolysis, uterine clearance after insemination and post partum. Nevertheless, if excessive or persistent, inflammation can switch from a positive mechanism to a deleterious process, im
Anim. Reprod.. Publicado em: 28/11/2019
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11. Phase and microstructural analysis of NdTi0.8M0.2O3.4 (M = Al, Ga) microwave ceramics
ABSTRACT In this paper, we report the characterization of NdTi0.8M0.2O3.4 (M = Ga, Al) ceramics prepared via mixed oxide solid state sintering route. X-ray diffraction analysis of the samples revealed the formation of single phase for NdTi0.8Ga0.2O3.4 sample while secondary phase was formed in the case of NdTi0.8Al0.2O3.4. Microstructural analysis of the sam
Matéria (Rio J.). Publicado em: 25/11/2019
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12. Fine-tuning multilevel modeling of risk factors associated with nonsurgical periodontal treatment outcome
Abstract This retrospective study evaluated the influence of known risk factors on nonsurgical periodontal treatment (NSPT) response using a pocket depth fine-tuning multilevel linear model (MLM). Overall, 37 patients (24 males and 13 females) with moderate-to-severe chronic periodontitis underwent NSPT. Follow-up visits at 3, 6, and 12 months included measu
Braz. oral res.. Publicado em: 26/08/2019