Browsing Artículos by Title
Now showing items 10029-10048 of 10507
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Ultrafast entanglement switching and singlet-triplet transitions control via structured terahertz pulses
(IOP, 2022)[EN] Terahertz (THz) vector beams with spatially textured polarization are proposed to steer the spin and spatial distributions of two interacting electrons in a quantum dot. We study theoretically the spatiotemporal ... -
Ultrahigh Superelastic Damping at the Nano-Scale: a Robust Phenomenon to Improve Smart MEMS Devices
(Elsevier, 2019-03)Micro and nano pillars of Copper-based shape memory alloys (SMAs) with feature sizes between about 2 mu m and 250 nm are known to exhibit ultra-high mechanical damping due to the nucleation and motion of stress-induced ... -
Ultraprecise Controller for Piezoelectric Actuators Based on Deep Learning and Model Predictive Control
(MDPI, 2023-02-03)Piezoelectric actuators (PEA) are high-precision devices used in applications requiring micrometric displacements. However, PEAs present non-linearity phenomena that introduce drawbacks at high precision applications. One ... -
Ultrasonic Guided Wave Testing on Cross-Ply Composite Laminate: An Empirical Study
(MDPI, 2020-09-16)Structural health monitoring comprises a set of techniques to detect defects appearing in structures. One of the most viable techniques is based on the guided ultrasonic wave test (UGWT), which consists of emitting waves ... -
Ultrasound and Eco-Detergents for Sustainable Cleaning
(MDPI, 2023-07-12)Green chemistry faces a major challenge imposed by the Sustainable Development Goals (6, 14 and 15) defined in the 2030 Agenda. In the case of cleaning products (detergents), the challenges often become a paradox: even if ... -
Ultrasound Tumor Size Assessment, Histology and Serum Enzyme Analysis in a Rat Model of Colorectal Liver Cancer
(Elsevier, 2020-06)During tumor development, tissue necrosis appears as a natural phenomenon directly associated with an increase in tumor size. The aim of this study was to assess the use of ultrasound (US) for predicting natural tumor ... -
Ultrasound-Assisted “Green” Extraction (UAE) of Antioxidant Compounds (Betalains and Phenolics) from Opuntia stricta var. Dilenii’s Fruits: Optimization and Biological Activities
(MDPI, 2021-11-08)Opuntia stricta var. Dillenii’s prickly pears are an underutilized fruit with a high content of betalains and phenolic compounds that could bring potential health benefits for humans. The aim of this study is the optimization ... -
Ultrasound-based structural health monitoring methodology employing active and passive techniques
(Elsevier, 2023-04)Currently, structures are examined during manufacturing by means of Non Destructive Tests (NDT), but there is an increasing interest in monitoring its integrity over its whole life cycle by using Structural Health Monitoring ... -
Um Reino e as suas Repúblicas no Atlântico. Comunicações Políticas entre Portugal, Brasil e Angola nos Séculos XVII e XVIII: Rio de Janeiro, Civilização Brasileira
(Instituto de Ciências Sociais da Universidade de Lisboa, 2019-12)... -
Uncertainties in the Testing of the Coefficient of Thermal Expansion of Overhead Conductors
(MDPI, 2020-01-14)Overhead lines can be replaced by high temperature low sag (HTLS) conductors in order to increase their capacity. The coe cients of thermal expansion (CTE) of the HTLS conductors are lower than the CTE of conventional ... -
Uncertainty and detection limits of Pu-241 determination by liquid scintillation counting (LSC)
(Elsevier, 2021-10)[EN]Determination of Pu-241 is an essential issue for radiation protection, as it is the precursor of some nuclides with high radiotoxicity. Pu-241 is a low energy beta emitter, which makes its measurement more challenging ... -
Uncharted Stable Peninsula for Multivariable Milling Tools by High-Order Homotopy Perturbation Method
(MDPI, 2020-11-06)In this work, a new method for solving a delay differential equation (DDE) with multiple delays is presented by using second- and third-order polynomials to approximate the delayed terms using the enhanced homotopy ... -
Unconventional Approaches in Coordination Chemistry and Organometallic Reactivity
(American Chemical Society, 2021-03-23)This contribution highlights a number of approaches developed by coordination and organometallic chemists that go beyond mainstream inorganic reactivity. A few of these strategies have been known for decades and are ... -
Unconventional spin texture of a topologically nontrivial semimetal Sb(110)
(IOP Publishing LTD, 2012-10-17)The surfaces of antimony are characterized by the presence of spin-split states within the projected bulk band gap and the Fermi contour is thus expected to exhibit a spin texture. Using spin-resolved density functional ... -
Uncovering Ecosystem Service Bundles through Social Preferences
(Public Library of Science, 2012-06-18)Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension ... -
Uncovering Success Patterns in Track Cycling: Integrating Performance Data with Coaches and Athletes’ Perspectives
(MDPI, 2024-04-08)Track cycling entails a challenging progression from the youth categories to elite competition. Hence, this study aimed to investigate the importance of early performance and various publicly available performance indicators ... -
Uncovering the Concerns and Needs of Individuals with Celiac Disease: A Cross-Sectional Study
(MDPI, 2023-08-22)The treatment for celiac disease (CD) involves a strict gluten-free diet, which can be challenging and lead to questions for patients. Pinpointing these uncertainties can enable the creation of efficient educational ... -
Undergraduate business students´perception of auditing: impact of proximity and knowledgeon auditors´stereotype
(Emerald Publishing Limited, 2021-07-22)Purpose – This study aims to explore undergraduate students’ stereotypes of auditing and the influence of knowledge of the profession and its sources on the stereotype. Design/methodology/approach – This study is based ... -
Understanding Cash Sharing: A Sustainability Model
(MDPI, 2019-03-20)Traditionally, corporate treasury management has been strategically based on the idea of advancing collections and delaying payments, which has been regulated through the intermediation of financial entities using, for ... -
Understanding Density in an Uneven City, Santiago de Chile: Implications for Social and Environmental Sustainability
(MDPI, 2014-09-02)Efforts to promote infill development and to raise densities are growing in many cities around the world as a way to encourage urban sustainability. However, in cities polarized along socio-economic lines, the benefits of ...