Universidade Federal de Itajubá

On the invariant sphere theorem with emphasis in the round sphere S n $\mathbb S^n$ double struck upper S Superscript n

Abstract This article discusses vector fields in R n $\mathbb R^n$ double struck upper R Superscript n , n ≥ 3 $n \geq 3$ n greater than or equals 3 , that can be written as the sum of a radial repelling vector field and an attracting nonlinear homogeneous vector field of odd deg...

Positive solutions of singular elliptic problems with unbounded exponents and unbounded convection term

Abstract In this paper, we study the existence and nonexistence of positive solutions for a class of Dirichlet problems with a singularity and a convection term. Precisely, we consider the existence of a positive solution to the Dirichlet problem $$\begin{aligned} -\Delta _p u =...

Environmental performance of hydrogen production via eucalyptus biomass gasification and natural gas steam reforming: A life cycle assessment approach

A life cycle assessment (LCA) was conducted to compare hydrogen production via steam methane reforming (SMR) of natural gas and eucalyptus biomass gasification under Brazilian conditions. Three scenarios were evaluated for the production of 1 kg of hydrogen: (i) SMR, (ii) SMR wit...

Efficiency analysis and evaluation 4E of a hybrid solar photovoltaic-electric dryer for Brewer’s Spent Grain drying

Brewer’s Spent Grain (BSG) is the main by-product of the brewing industry and, due to its high moisture content, presents challenges for storage, transportation, and valorization. When properly dried, however, BSG becomes a biomass with significant energy potential. Considering t...

Damage detection, localization, and sizing in composite structures using modal shape and multi-head convolutional neural network

Abstract Owing to their favorable weight-to-performance characteristics, composite sandwich panels are extensively employed across engineering sectors; however, internal defects often escape identification when relying on conventional, visually-driven inspection routines. This st...

Western amazon 2020 extreme heatwave

Abstract Between September and November 2020, an extreme climate event characterized by the co-occurrence of severe drought, extreme heat stress, widespread burning, and respiratory health impacts affected southwestern Amazonia. This study investigated the event using an integrat...

Thermodynamic and Structural Evidence for Higher-Order Selegiline with Carboxymethyl-β-Cyclodextrin Supramolecular Assemblies in Aqueous Solution

Abstract The supramolecular interactions between selegiline hydrochloride (SEL) and β-cyclodextrin (βCD) derivatives were investigated through isothermal titration calorimetry (ITC), nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations. Thermodynamic analyses...

Skin Cancer in Rural Workers in Brazil: Influence of Ultraviolet Radiation, Skin Color and Regional Factors

BACKGROUND: This study analyzed the incidence of skin cancer among rural workers in Brazil, considering the influence of ultraviolet (UV) radiation, skin color, and regional factors. METHODS: Data from the National Cancer Institute (2008-2022) on skin cancer were used, using hist...

Dynamic drivers of an extreme heatwave over the UK in July 2022

Abstract Slow‑moving synoptic structures have been hypothesized to be a part of severe heatwave events over extended continental regions in summer, highlighting the potential impacts of the growing climate emergency associated with rising background temperatures. In this context,...

Magnetic susceptibility of magnetorheological fluids: Experimental assessment of mixing rules and an empirical formulation

This study systematically evaluates mixing-rule models for predicting the effective magnetic permeability of magnetorheological fluids (MRFs) from weak-field susceptibility measurements. Carbonyl iron powder suspensions in glycerol were prepared over 14 particle volume fractions,...