Pulse Sequence
Mostrando 1-12 de 298 artigos, teses e dissertações.
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1. Droplet Size Distribution in Water-Crude Oil Emulsions by Low-Field NMR
This paper reports the droplet size distribution (DSD) measurements in 28 W/O (water/oil) crude oil emulsions prepared with two Brazilian oils (medium and heavy) under different shear conditions using both 10 g L-1 NaCl solution and water production by low field nuclear magnetic resonance (NMR, 2.2 MHz). The PFGSTE (pulsed-field gradient-stimulated echo) pul
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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2. (+)-BINOL and Pure Shift Experiment: A Bidirectional Approach for NMR Chiral Discrimination of Overcrowded Spectra of Primary Amines
In this work, enantiopure 1,1’-bi-2-naphthol (BINOL) derivatives and carboxylic acids were evaluated as chiral solvating agents (CSAs) in the nuclear magnetic resonance (NMR) chiral discrimination of primary amines. Among the CSAs screened, the readily available (+)-BINOL revealed a simple and rapid chiral auxiliary for 1H NMR chiral discrimination. The pr
J. Braz. Chem. Soc.. Publicado em: 2018-08
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3. Efecto del tiempo de superpulso de soldadura sobre la evolución microestructural de un acero de bajo carbono
ABSTRACT The Super Pulse arc type was developed to provide a solution to butt root pass beads in the semi-automatic welding process with gas protection (GMAW). Unlike standard pulse welding, the Super Pulse uses a sequence of different pulse waveforms to create a cord shape and appearance similar to the GTAW process. It uses higher amperage in the primary ph
Matéria (Rio J.). Publicado em: 19/07/2018
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4. Stratigraphic Relations of the Ipubi Formation: Siliciclastic-Evaporitic Succession of the Araripe Basin
ABSTRACT The Ipubi Formation represents the Aptian-Albian siliciclastic-evaporitic succession of Araripe Basin, NE Brazil. This succession comprises siliciclastic rocks (bituminous shales and claystones) and evaporites (gypsum and secondary anhydrite) and represents part of the lacustrine-shallow marine post-rift phase I. This study used sequence stratigraph
An. Acad. Bras. Ciênc.. Publicado em: 25/06/2018
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5. Resting spontaneous baroreflex sensitivity and cardiac autonomic control in anabolic androgenic steroid users
OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, w
Clinics. Publicado em: 21/05/2018
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6. AMPEROMETRIC DETERMINATION OF 8-CHLOROTHEOPHYLLINE, CAFFEINE, AND DIPHENHYDRAMINE IN A SINGLE RUN
A simple method for simultaneous determination of 8-chlorotheophylline (CTP), caffeine (CAF), and diphenhydramine (DIP) using batch-injection analysis with multiple pulse amperometric detection (BIA-MPA) is reported. A sequence of three potential pulses (+1.10 V, +1.40 V, and +1.70 V) was applied to the boron-doped diamond working electrode with the acquisit
Quím. Nova. Publicado em: 2017-08
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7. A magneto-motive ultrasound platform designed for pre-clinical and clinical applications
Abstract Introduction Magneto-motive ultrasound (MMUS) combines magnetism and ultrasound (US) to detect magnetic nanoparticles in soft tissues. One type of MMUS called shear-wave dispersion magneto-motive ultrasound (SDMMUS) analyzes magnetically induced shear waves (SW) to quantify the elasticity and viscosity of the medium. The lack of an established pres
Res. Biomed. Eng.. Publicado em: 12/01/2017
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8. Method to Determine the Electrical Energy for Ignition of Electro-Explosive Devices
ABSTRACT: During field trials, it was observed that the delay of ignition of electro-explosive devices (EED) depends on ratings of power supplies or dynamo and also on the firing cable lengths. The change in ignition delay of EEDs due to altered supplied current will detoriate the repeatability of sequence of actions in time-critical armament applications. I
J. Aerosp. Technol. Manag.. Publicado em: 2015-09
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9. 1H HR-MAS NMR and S180 cells: metabolite assignment and evaluation of pulse sequence
Ressonância magnética nuclear de ¹H de alta resolução com giro no ângulo mágico (HR-MAS NMR) é uma técnica empregada na avaliação de células e tecidos intactos. Entretanto, parâmetros bem estabelecidos de NMR são cruciais para a obtenção de resultados confiáveis. A fim de discutir as principais etapas envolvidas na otimização das análises
J. Braz. Chem. Soc.. Publicado em: 2014-06
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10. Galvanic vestibular stimulator for fMRI studies
INTRODUCTION: Areas of the brain that are associated with the vestibular system can be activated using galvanic vestibular stimulation. These areas can be studied through a combination of galvanic vestibular stimulation with functional magnetic resonance imaging (fMRI). In order to provide an appropriate sequence of galvanic stimulation synchronous with the
Rev. Bras. Eng. Bioméd.. Publicado em: 2014-03
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11. Stacking sequence optimisation of composite panels subjected to slamming impact loads using a genetic algorithm
Optimisation of stacking sequence for composite panels under slamming impact loads using a genetic algorithm method is studied in this paper. For this purpose, slamming load is assumed to have a uniform distribution with a triangular-pulse type of intensity function. In order to perform optimisation based on a genetic algorithm, a special code is written in
Lat. Am. j. solids struct.. Publicado em: 2013-09
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12. Effect of scanner acoustic background noise on strict resting-state fMRI
Functional MRI (fMRI) resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state’ fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influ
Braz J Med Biol Res. Publicado em: 12/04/2013