Search results for "EMT"
showing 10 items of 413 documents
Photoemission time-of-flight spectromicroscopy of Ag nanoparticle films on Si(111)
2004
Abstract Time-of-flight photoemission electron microscopy was used to measure spatially resolved energy distribution curves of electrons emitted from Ag nanoparticle films with different mass thicknesses. Two-photon photoemission (2PPE) was induced by femtosecond laser pulse excitation with 3.1 eV photon energy and 200 fs pulse width. Regions of Ag nanoparticles with different average sizes and one region with a continuous 100 nm thick Ag film were deposited as a stepped wedge on a Si(1 1 1) substrate. Upon laser excitation the nanoparticle films exhibit a very high electron emission yield in the images, whereas the uncovered Si surface and the continuous Ag film are dark. The time-of-fligh…
Multiphoton photoemission electron microscopy using femtosecond laser radiation
2002
Abstract The interaction of intense, pulsed laser radiation with surfaces results in non-linear optical effects that are responsible for emission of electrons even if the photon energies are below the work function. In the present study, photoelectrons have been excited by means of femtosecond laser pulses from a frequency doubled Ti:sapphire laser with a photon energy of 3.1 eV. The spatial distribution of the photo emitted electrons was imaged using a photoemission electron microscope. All samples exhibit centres of enhanced second or higher order photoemission yield, so called ‘hot spots’. These ‘hot spots’ were preferentially excited with s-polarised light. This behaviour may be explain…
Kapitāla struktūra un aizņemtā kapitāla piesaistīšanas iespējas SIA "Merits"
2015
Bakalaura darba tēma ir ‘’Kapitāla struktūra un aizņemtā kapitāla piesaistīšanas iespējas SIA ‘’Merits’’ ‘’. Darba mērķis ir izpētīt uzņēmuma SIA ‘’Merits’’ kapitāla struktūru un aizņemtā kapitāla piesaistīšanas iespējas, kā arī izstrādāt priekšlikumus uzņēmuma kapitāla struktūras uzlabošanai un izdevīgākam aizņemtā kapitāla piesaistes veidam. Teorētiskajā daļā tiek izanalizēta ekonomiskā literatūra par uzņēmumu kapitāla struktūru, to teorētisko novērtēšanu un aktuālākie aizņemtā kapitāla piesaistīšanas veidi. Praktiskā daļa sastāv no divām nodaļām. Pirmajā praktiskās daļas nodaļā autore izanalizē uzņēmuma SIA ‘’Merits’’ kapitāla struktūru. Otrā praktiskā daļa sastāv no aizņemtā kapitāla pi…
Coherent master equation for laser modelocking
2020
Modelocked lasers constitute the fundamental source of optically-coherent ultrashort-pulsed radiation, with huge impact in science and technology. Their modeling largely rests on the master equation (ME) approach introduced in 1975 by Hermann A. Haus. However, that description fails when the medium dynamics is fast and, ultimately, when light-matter quantum coherence is relevant. Here we set a rigorous and general ME framework, the coherent ME (CME), that overcomes both limitations. The CME predicts strong deviations from Haus ME, which we substantiate through an amplitude-modulated semiconductor laser experiment. Accounting for coherent effects, like the Risken-Nummedal-Graham-Haken multim…
Cancer Stem Cells: to be or not to be, is that the problem?
2014
Colon cancer stem cells: to be or not to be, is that the problem?
2014
GaN and SiC Device Characterization by a Dedicated Embedded Measurement System
2023
This work proposes a comparison among GaN and SiC device main parameters measured with a dedicated and low-cost embedded system, employing an STM32 microcontroller designed to the purpose. The system has the advantage to avoid the use of expensive laboratory measurement equipment to test the devices, allowing to obtain their behavior in operating conditions. The following KPIs (Key Performance Indicators) are measured and critically compared: threshold voltage, on-resistance and input capacitance. All the measurements are carried out in a short time interval and on a wide range of switching frequencies, ranging from 10 kHz to 1 MHz. This investigation is focused on the deviation of the figu…
The spatial distribution of non-linear effects in multi-photon photoemission from metallic adsorbates on Si(1 1 1)
2001
Multi-photon excitations from thin metallic films on silicon substrates have been observed utilising photoemission electron microscopy. The photoelectrons have been excited by means of high power femtosecond laser pulses with a photon energy below the work function threshold. The strong spatial variations of the non-linear effects became directly visible in electron emission from the adsorbed thin films. Centres of enhanced photoelectron yield, so-called hot spots, were observed on the surfaces of various samples. The multi-photon electron yield of the metallic films (permalloy and lead) depends strongly on the sample topography and the photon polarisation.
Il riconoscimento del diritto umano alla conoscenza, il legato del Prof. M. Cherif Bassiouni,
2018
l'articolo ricorda Il Professor Bassiouni, figura eminente tra gli studiosi di diritto penale internazionale, é stato nominato per 22 importanti incarichi delle Nazioni Unite, tra le quali: Presidente e poi membro della Commissione d'inchiesta per la Libia (2011-12), Esperto Indipendente sui diritti umani per l'Afghanistan (2004-06), Esperto Indipendente sui diritti di restituzione, compensazione e riabilitazione per le vittime di gravi violazioni dei diritti umani e delle libertà fondamentali (1998-2000). Numerosi anche i riconoscimenti e premi ricevuti: la Nomination al premio Nobel per la Pace (1999), la Medaglia G. T. Butcher dell'American Society of Law (2014), il Premio per i diritti…