Search results for "Transient"

Minimally Invasive Video-Assisted Thyroidectomy: Analysis of Complications From a Systematic Review

2019

Background. Nowadays, minimally invasive video-assisted thyroidectomy (MIVAT) is considered a safe and effective option. However, its complication rate has not been specifically discussed yet. The aim of this systematic review was enrolling a large number of studies to estimate early and late complications (transient and definitive, uni- and bilateral laryngeal nerve palsy; transient and definitive hypocalcemia; cervical hematoma; hypertrophic or keloid scar) of MIVAT compared with conventional technique. Methods. The review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria in PubMed and Embase. Search terms were “minimally inva…

Reduced Admissions for Cerebrovascular Events during COVID-19 Outbreak in Italy

2020

Supplemental Digital Content is available in the text.

Inter-area oscillations in the 500-kV Vietnamese power system

2019

The paper presents the study of the 500-kV Vietnamese power system. The oscillatory response of the system is analyzed both with a modal analysis and a time domain analysis. The 500-kV system of Vietnam is modeled in details, including all the power plants with the corresponding regulators. The model is developed in collaboration with the Institute of Energy Science IES-VAST of Vietnam and it is validated with the data provided by the National Load Dispatch Centre (NLDC) of Vietnam. The simulation results reveal a clear identification of potential inter-area oscillations between North and South of the Country. A worsening of the observed phenomenon should be considered as possible, especial…

Transient stability simulation of a fixed speed wind turbine by Matlab/Simulink

2007

This paper describes the dynamic behavior of a typical fixed speed wind turbine connected to the grid; the model is developed in the simulation tool Matlab/Simulink and created as a modular structure. The pitch control system is used for stabilization of the wind turbine at grid faults. In this way, voltage stability of the system with grid-connected wind turbines can be improved by using blade-angle control for a temporary reduction of the wind turbine power during a short-circuit fault in the grid. This paper shows a new variable control for maintaining of voltage stability, when a three-phase fault is applied close to the wind turbine and cleared by disconnecting the affected line. In th…

Photodynamics of a Molecular Water-Soluble Nanocluster Identified as Au130(pMBA)50

2015

Photodynamics of a highly monodisperse sample of a water-soluble gold nanocluster tentatively identified as Au130(pMBA)50 (pMBA = p-mercaptobenzoic acid) was studied by mid-IR transient absorption spectroscopy with visible excitation. The observed long-lived excited states (>1 ns) indicate a molecular behavior of the cluster. By combining the transient absorption data with DFT calculation results the observed relaxation dynamics could be fully explained by identifying several relaxation processes involving singlet and triplet manifolds. The results indicate that the cluster may have interesting transient magnetic properties due to a long-lived triplet population.

Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers

2020

The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the high temperature GaN buffer and the QW region. Capacitance-voltage profiling with monochromatic illumination showed that in the InGaN underlayer (UL), the density of deep traps with optical threshold near 1.5 eV was much higher than in the QW and higher than for structures without InGaN. Irradiation with 5 MeV electrons strongly increased the concentration of these 1.5 eV traps in the QWs, with the increase more pronounced for samples witho…

Experimental test on a fuel cell-supercapacitor hybrid power supply for a digital still camera

2009

Triggering a transient organo-gelation system in a chemically active solvent

2021

A transient organo-gelation system with spatiotemporal dynamic properties is described. Here, the solvent actively controls a complex set of equilibria that underpin the dynamic assembly event. The observed metastability is due to the in situ formation of a secondary solvent, acting as an antagonist against the primary solvent of the organogel. peerReviewed

Nanoscale probing of the supramolecular assembly in a two‐component gel by near‐field infrared spectroscopy

2023

The design of soft biomaterials requires a deep understanding of molecular self-assembly. We introduce here a nanoscale infrared (IR) spectroscopy study of a two-component supramolecular gel to assess the system´s heterogeneity and supramolecular assembly. In contrast to far-field IR spectroscopy, near-field IR spectroscopy revealed differences in the secondary structures of the gelator molecules and non-covalent interactions at three distinct nano-locations of the gel network. A β-sheet arrangement is dominant in single and parallel fibres with a small proportion of an α-helix present, while the molecular assembly derives from strong hydrogen bonding. However, at the crossing point of two …

Feasibility study of a combi-PV panel for greenhouse energy supply and water recovery by nightly radiation towards the sky

2011

In southern European areas, characterized by high irradiation, the use of water for both evaporative cooling systems and hydroponic fertigation, represents a serious drawback for crop cultivation under cover. Water recovery systems seem to be an attractive solution, especially when they are integrated in the greenhouse construction. In this research, a feasibility study of applying a water recovery system driven by a combi-PV panel, in a semi-closed greenhouse was carried out. The prototype combi-PV panel was made by coupling an amorphous silicon panel with a sump stacked on the rear PV panel surface and filled with saline water. The system is driven by a cold-heat sink which is the PV pane…