Search results for "switch"
showing 10 items of 467 documents
Photoactive Yellow Protein Chromophore Photoisomerizes around a Single Bond if the Double Bond Is Locked
2020
Photoactivation in the Photoactive Yellow Protein, a bacterial blue light photoreceptor, proceeds via photo-isomerization of the double C=C bond in the covalently attached chromophore. Quantum chemistry calculations, however, have suggested that in addition to double bond photo-isomerization, the isolated chromophore and many of its analogues, can isomerize around a single C-C bond as well. Whereas double bond photo-isomerization has been observed with x-ray crystallography, experimental evidence for single bond photo-isomerization is currently lacking. Therefore, we have synthesized a chromophore analogue, in which the formal double bond is covalently locked in a cyclopentenone ring and ca…
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…
»just de niillä oli sovmorgon» : Kulturella och pragmatiska aspekter på kodväxling i tvåspråkiga ungdomssamtal i Haparanda, Stockholm och Helsingfors
2017
The aim of the study is to explore situational, cultural and pragmatic factors that might trigger code-switching during informal conversations outside of the classroom at school among bilingual adolescents in Haparanda, Helsinki and Stockholm. An attempt is made to clarify different functions of code-switching, i.e. why bilingual adolescents code-switch from Swedish to Finnish and vice versa. The conversational data, consisting of video-recorded group and pair conversations, was collected in 2014–2015 at six junior high schools in Haparanda, Helsinki and Stockholm. The analysis of the data is qualitative. The theoretical framework is found in the field of translanguaging, which aims to desc…
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, …
Wall mannoproteins in cells from colonial phenotypic variants of Candida albicans.
1990
Candida albicans ATCC 26555 switched at high frequency (10(-1) to 10(-3)) between several phenotypes identified by colony morphology on a defined mineral amino-acid-containing agar medium supplemented with arginine and zinc (LAZ medium). When cells taken from colonies exhibiting distinct morphologies were plated directly onto LAZ agar, spontaneous conversion to all the variant phenotypes occurred at combined frequencies of 2.1 x 10(-1) to 9.5 x 10(-3). However, when cells taken from the different colonial phenotypes were plated directly onto an undefined medium (yeast extract/peptone/dextrose; YPD medium), or first incubated in liquid YPD medium and then cloned on YPD agar, all colonies obs…
Expansion and Compression of a Helicate with Central Diol-Units as Stereocontrolling Moieties
2022
The dicatechol ester ligand 2-H4 forms the compressed helicate Li4[(2)3Ti2] which upon removal of the internally bound lithium cations expands. In the compressed form, the chiral diol units control the stereochemistry of the complex which is lost upon expansion of the system. peerReviewed
From a Finnish player to an English avatar : language alternation in immersive video gaming sessions
2015
Videopelien pelaamisesta on tullut suosittu harrastus, joka sisältää usein aktiivista ja monikielistä kommunikointia pelaajien kesken. Pelaamisen sosiaalisuutta ja keskustelijoiden koodinvaihtoa käsittelevän tutkimuksen asetelmat ovat keskittyneet yhdellä ruudulla pelattaviin konsolipeleihin, vaikka internet on mahdollistanut etämoninpelaamisen ja ääniviestien välittämän vuorovaikutuksen. Kokemus virtuaaliseen maailmaan eläytymisestä voi muovata pelaajien välistä keskustelua, ja ilman kehonkieltä kielellisillä valinnoilla on pelaajien reaktioiden sekä hahmoihin samaistumisen ilmaisemisessa entistä suurempi rooli. Tämän tutkielman tarkoitus oli selvittää, mihin tarkoituksiin ja kuinka laajas…
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 …