Characteristic
Mostrando 1-12 de 11740 artigos, teses e dissertações.
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1. Synthesis of delafossite CuCrO2 via solution combustion method and its acid functionalization for biodiesel production
Abstract CuCrO2 was synthesized by solution combustion synthesis (SCS) and applied as a heterogeneous catalyst to produce soybean biodiesel. The combustion reaction was carried out using urea as a fuel, and copper (II) and chromium (III) nitrates as precursors. After the powders’ obtention, these were calcined and functionalized in an acidic medium. The po
Cerâmica. Publicado em: 2023
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2. VIBRATION CHARACTERISTICS, CHEMICAL BONDS AND WEAK INTERACTIONS OF 4- AND 5-HYDROXYSALICYLIC ACID INVESTIGATED BY TERAHERTZ SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY
The terahertz (THz) absorption spectra of 4- and 5-hydroxysalicylic acid were measured by terahertz time-domain spectroscopy (THz-TDS) in the range of 0.4-2.8 THz. The unit cells of both were calculated by density functional theory (DFT), and the theoretical simulation and experimental data were basically in agreement. To further interpret the origin of the
Química Nova. Publicado em: 2022
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3. K2O SUPORTADO EM ZEÓLITA NATURAL: SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO PRODUÇÃO DE BIODIESEL A PARTIR DO ÓLEO DE GIRASSOL
Biodiesel is a renewable fuel, a substitute for fossil diesel, which is important for reducing GHG in Brazil. Therefore, this work aims to synthesize and characterize the catalyst using the support of natural zeolite impregnated with K2O and apply it in the production of biodiesel through the transesterification reaction. Through the analysis of characteriza
Química Nova. Publicado em: 2022
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4. Hybrid Quaternions of Leonardo
ABSTRACT In this article, we intend to investigate the Leonardo sequence presenting the hybrid Leonardo quaternions. To explore Hybrid Quaternions of Leonardo, the priori, sequence of Leonardo, quaternions and hybrid numbers were presented. Soon after, its recurrence, characteristic equation, its relation with the Fibonacci quaternions, generating function,
Trends in Computational and Applied Mathematics. Publicado em: 2022
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5. Effectiveness of galvanic vestibular evoked myogenic potential for evaluation of Meniere’s disease
Abstract Objectives: Although the cause of Meniere’s disease (MD) is not fully understood, endolymphatic hydrops is widely believed to be responsible for MD. Previous studies have used Air-Conducted Sound (ACS)-induced Vestibular Evoked Myogenic Potentials (VEMPs) to evaluate otolithic function in patients with MD. However, the use of Galvanic Vestibular
Brazilian Journal of Otorhinolaryngology. Publicado em: 2022
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6. Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst
In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Nomogram for predicting post-traumatic hydrocephalus after decompressive craniectomy for traumatic brain injury
SUMMARY OBJECTIVE: This study aimed to develop and validate a practical nomogram to predict the occurrence of post-traumatic hydrocephalus in patients who have undergone decompressive craniectomy for traumatic brain injury. METHODS: A total of 516 cases were enrolled and divided into the training (n=364) and validation (n=152) cohorts. Optimal predictors w
Revista da Associação Médica Brasileira. Publicado em: 2022
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8. Comparison of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality among geriatric coronavirus disease 2019 patients
SUMMARY OBJECTIVE: The aim of this study was to evaluate and compare C-reactive protein and C-reactive protein-to-albumin ratio performances in predicting mortality of geriatric patients who visited the emergency department. METHODS: The data of patients with COVID-19 and aged 65 years and above, who visited emergency department during the study period,
Revista da Associação Médica Brasileira. Publicado em: 2022
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9. Systemic immune-inflammation index as a novel predictor of atrial fibrillation after off-pump coronary artery bypass grafting
SUMMARY OBJECTIVE: This study aims to examine the predictive role of systemic immune-inflammation index on postoperative new-onset atrial fibrillation in patients undergoing off-pump coronary artery bypass grafting. METHODS: A total of 722 patients undergoing elective off-pump coronary artery bypass grafting between January 2017 and September 2021 were inc
Revista da Associação Médica Brasileira. Publicado em: 2022
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10. Predição de choque séptico e hipovolêmico em pacientes de unidade de terapia intensiva com o uso de machine learning
RESUMO Objetivo: Criar e validar um modelo de predição de choque séptico ou hipovolêmico a partir de variáveis de fácil obtenção coletadas na admissão de pacientes internados em uma unidade de terapia intensiva. Métodos: Estudo de modelagem preditiva com dados de coorte concorrente realizada em um hospital do interior do nordeste brasileiro. Fora
Revista Brasileira de Terapia Intensiva. Publicado em: 2022
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11. Does asporin have a role in polycystic ovary syndrome? A pilot study
SUMMARY OBJECTIVE: Asporin is secreted by theca cells in the mouse ovaries and is an effective marker at the gonadotropin-independent stage in secondary follicle development. It has an inhibitory effect on transforming growth factor beta and bone morphogenic proteins, which are involved in androgenesis process. Our aim was to compare serum asporin levels of
Revista da Associação Médica Brasileira. Publicado em: 2022
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12. Strong Stability Preserving Runge-Kutta Methods Applied to Water Hammer Problem
ABSTRACT The characteristic method of lines is the most used numerical method applied to the water hammer problem. It transforms a system of partial differential equations involving the independent variables time and space in two ordinary differential equations along the characteristics curves and then solve it numerically. This approach, although showing gr
Trends in Computational and Applied Mathematics. Publicado em: 2022