Search results for "Switche"

Proton‐Gated Ring‐Closure of a Negative Photochromic Azulene‐Based Diarylethene

2020

Abstract Proton‐responsive photochromic molecules are attractive for their ability to react on non‐invasive rapid optical stimuli and the importance of protonation/deprotonation processes in various fields. Conventionally, their acidic/basic sites are on hetero‐atoms, which are orthogonal to the photo‐active π‐center. Here, we incorporate azulene, an acid‐sensitive pure hydrocarbon, into the skeleton of a diarylethene‐type photoswitch. The latter exhibits a novel proton‐gated negative photochromic ring‐closure and its optical response upon protonation in both open and closed forms is much more pronounced than those of diarylethene photoswitches with hetero‐atom based acidic/basic moieties. …

Network Capacity Estimators Predicting QoE in HTTP Adaptive Streaming

2022

The aim of adaptive HTTP streaming technology is preserving the best possible video streaming quality for viewers in heterogeneous network conditions. This can be achieved by making multiple quality versions of the video available. Switching between versions during playback should be imperceptible and fluent. The decision about quality-level switching is typically based on network capacity estimation and buffer occupancy, which predict the risk of stalling. Since quality-level switching and stalling are directly evident to the user, they are often classified as influence factors of quality of experience (QoE). In this paper, we observe different network capacity estimators and buffer behavi…

Chemical design of coordination polymers and functional materials: from pore control in MOFs through spin dynamics in nanomagnets to rotaxanes in mol…

2022

El trabajo de esta tesis se enmarca en el diseño químico de polímeros de coordinación y de materiales funcionales para poder ser utilizados en el campo de los materiales moleculares. El capítulo 1 ofrece una visión de los avances más significativos en la química de coordinación, así como una introducción general de los materiales moleculares más relevantes en la actualidad. El objetivo es proporcionar al lector el conocimiento necesario para establecer las bases sobre los campos a tratar. El resto de capítulos está organizado de acuerdo con un aumento de la dimensionalidad, empezando con moléculas discretas y terminando con polímeros de coordinación. El capítulo dos describe dos estructuras…

Electrochemically triggered iodide-vacancy BiOI film for selective extraction of iodide ion from aqueous solutions

2021

Abstract The effective extraction and regeneration of radioactive iodide remains an urgent concern for safe nuclear energy utilization. Herein, we developed a novel electrochemically triggered iodide-vacancy BiOI film, which exhibited excellent I− ion extraction capacity of 328.3 mg·g−1. Especially, due to the ion vacancy trap effect, the film showed high selectivity towards I− ions in the existence of a large number of competitive anions. Additionally, the electrochemically switched ion extraction (ESIE) process with this iodide-vacancy BiOI film possessed fast extraction kinetics and high stability. More importantly, the trapped I− ions were easily desorbed from the film without the secon…

Robust fault detection for switched systems with time-varying delay using delta operator approach

2014

Impact of Nonlinear Inductor on Efficiency and Power Losses in a SMPS: a Case Study

2022

This paper proposes a comparative analysis focused on losses in two Switched Mode Power Supplies, adopting a linear inductor and an inductor operated up to saturation, respectively. The use of the nonlinear inductor saves weight and cost on the magnetic material, which is of great interest for automotive applications; however, it increases the peak current and can increase losses. The analysis aims to compare, by simulations, the impact on the efficiency of the different current waveforms throughout the converter. The losses are discussed in detail and calculated for each component of the converters.

Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles

2009

[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…

Positive L1 observer design for positive Switched systems

2014

Published version of an article in the journal: Circuits, Systems, and Signal Processing. Also available from the publisher at: http://dx.doi.org/10.1007/s00034-013-9737-6 This paper investigates the problem of L1 observer design for positive switched systems. Firstly, a new kind of positive L1 observer is proposed for positive switched linear delay-free systems with observable and unobservable subsystems. Based on the average dwell time approach, a sufficient condition is proposed to ensure the existence of the positive L1 observer. Under the condition obtained, the estimated error converges to zero exponentially, and the L1 -gain from the disturbance input to the estimated error is less t…

Supramolecular Association of Halochromic Switches and Halloysite Nanotubes in Fluorescent Nanoprobes for Tumor Detection

2022

Fluorescence imaging has become an indispensable tool in the biomedical laboratory to elucidate the fundamental dynamic and structural factors regulating cellular processes. The development of fluorescent nanoprobes represents a challenge to detect any cellular process under a microscope. Herein, a fluorescent nanomaterial was synthesized by exploiting the supramolecular interaction between a halochromic switch (1Cl) and halloysite nanotubes (HNTs). The successful synthesis of a HNTs/1Cl nanomaterial was confirmed by thermogravimetric analysis and Fourier transform infrared. The aqueous mobility was investigated by dynamic light scattering and ζ-potential measurements as well. Furthermore, …

Current transformers effects on the measurement of harmonic active power in LV and MV networks

2011

The harmonic active power is used to determine the location of polluting loads, the direction of harmonic power flow and to estimate how consequential a certain current harmonic source is. The highest uncertainties, when measuring harmonic active power, are introduced by the current and voltage transducers. This paper presents experimental results which show the impact of current transformers (CTs) on the accuracy of the harmonic power measurements. An expression for the evaluation of the power error in distorted conditions was developed which can be easily utilized in the case of linear current transducers. It is shown how CTs cannot be considered linear transducers and how the higher the …