1. Measuring Thermal Diffusivity of Azoheteroarene Thin Layers by Photothermal Beam Deflection and Photothermal Lens MethodsAmeneh Mikaeeli, Dorota Koret, Humberto Cabrera, Dariusz Chomicki, Dariusz Dziczek, Oksana Kharchenko, Peng Song, Junyan Liu, Andreas D. Wieck, Michal Pawlak, 2023, original scientific article Keywords: thin films, photothermal spectroscopy, thermal transport, thermal wave, thermal conductivity, thermal diffusivity
Published in RUNG: 21.09.2023; Views: 117; Downloads: 1
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2. CR-ENTREES - Cosmic-Ray ENergy TRansport in timE-Evolving astrophysical SettingsAnita Reimer, Lukas Merten, Margot Boughelilba, Paolo Da Vela, Serguei Vorobiov, Jon Paul Lundquist, 2023, published scientific conference contribution Abstract: In order to understand observable signatures from putative cosmic-ray (CR) sources in-source
acceleration of particles, their energy and time-dependent transport including interactions in an
evolving environment and their escape from source have to be considered, in addition to sourceto-
Earth propagation.
We present the code CR-ENTREES (Cosmic-Ray ENergy TRansport in timE-Evolving astrophysical
Settings) that evolves the coupled time- and energy-dependent kinetic equations for cosmicray
nucleons, pions, muons, electrons, positrons, photons and neutrinos in a one-zone setup of
(possibly) non-constant size, with user-defined particle and photon injection laws. All relevant
interactions, particle/photon escape and adiabatic losses are considered in a radiation-dominated,
magnetized astrophysical environment that is itself evolving in time. Particle and photon interactions
are pre-calculated using event generators assuring an accurate interactions and secondary
particle production description. We use the matrix multiplication method for fast radiation and
particle energy transport which allows also an efficient treatment of transport non-linearities due
to the produced particles/photons being fed back into the simulation chain.
Examples for the temporal evolution of the non-thermal emission from AGN jet-like systems with
focus on proton-initiated pair cascades inside an expanding versus straight jet emission region, are
further presented.
Keywords: cosmic rays (CRs), CR energy transport, CR interactions, modeling
Published in RUNG: 24.08.2023; Views: 167; Downloads: 2
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3. Efficient Modeling of Heavy Cosmic Rays Propagation in Evolving Astrophysical EnvironmentsL. Merten, P. Da Vela, A. Reimer, M. Boughelilba, J. P. Lundquist, S. Vorobiov, J. Becker Tjus, 2023, published scientific conference contribution Abstract: We present a new energy transport code that models the time dependent and non-linear evolution
of spectra of cosmic-ray nuclei, their secondaries, and photon target fields. The software can inject
an arbitrary chemical composition including heavy elements up to iron nuclei. Energy losses and
secondary production due to interactions of cosmic ray nuclei, secondary mesons, leptons, or
gamma-rays with a target photon field are available for all relevant processes, e.g., photo-meson
production, photo disintegration, synchrotron radiation, Inverse Compton scattering, and more.
The resulting x-ray fluxes can be fed back into the simulation chain to correct the initial photon
targets, resulting in a non-linear treatment of the energy transport. The modular structure of the
code facilitates simple extension of interaction or target field models.
We will show how the software can be used to improve predictions of observables in various
astrophysical sources such as jetted active galactic nuclei (AGN). Since the software can model
the propagation of heavy ultrahigh-energy cosmic rays inside the source it can precisely predict
the chemical composition at the source. This will also refine predictions of neutrino emissions
–– they strongly depend on the chemical composition. This helps in the future to optimize the
selection and analyses of data from the IceCube neutrino observatory with the aim to enhance the
sensitivity of IceCube and reduce the number of trial factors.
Keywords: cosmic rays (CRs), CR energy transport, CR interactions, energy losses, modeling
Published in RUNG: 24.08.2023; Views: 173; Downloads: 2
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4. Time-of-flight photoconductivity investigation of high charge carrier mobility in Ti3C2Tx MXenes thin-filmJurij Urbančič, Erika Tomsič, Manisha Chhikara, Nadiia Pastukhova, Vadym Tkachuk, Andraž Mavrič, Gvido Bratina, Egon Pavlica, 2023, original scientific article Abstract: Charge transport through a randomly oriented multilayered network of two-dimensional (2D) Ti3C2Tx (where Tx is the surface termination and corresponds to O, OH and F) was studied using time-of-flight photoconductivity (TOFP) method, which is highly sensitive to the distribution of charge carrier velocities. We prepared samples comprising Ti3C2Tx with thickness of 12 nm or 6-monolayers. MXene flakes of size up to 16 μm were randomly deposited on the surface by spin-coating from water solution. Using TOFP, we have measured electron mobility that reached values up to 279 cm2/Vs and increase with electric-field in a Poole-Frenkel manner. These values are approximately 50 times higher than previously reported field-effect mobility. Interestingly, our zero-electric-field extrapolate approaches electron mobility measured using terahertz absorption method, which represents intra-flake transport. Our data suggest that macroscopic charge transport is governed by two distinct mechanisms. The high mobility values are characteristic for the intra-flake charge transport via the manifold of delocalized states. On the other hand, the observed Poole-Frenkel dependence of charge carrier mobility on the electric field is typical for the disordered materials and suggest the existence of an important contribution of inter-flake hopping to the overall charge transport.
Keywords: Charge transport in multilayered network of flakes, Time-of-flight photoconductivity, MXene exfoliation, High-mobility solution-cast thin-film, Semiconducting mxene
Published in RUNG: 31.03.2023; Views: 446; Downloads: 0
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5. Hidroelektrarna Sava KranjDrago Papler, 2020, professional article Keywords: električna energija, proizvodnja, hidroelektrarne, avtomatizacija, inovacije, čistilni stroji, obnova, transport, jez, hidromehanska oprema, agregati, turbine, generatorji, transformatorji, upravljalni sistemi, center vodenja
Published in RUNG: 29.03.2023; Views: 375; Downloads: 0
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7. Van der Waals heterostructuresVadym Tkachuk, doctoral dissertation Keywords: Graphene, hexagonal boron nitride, PDI8-CN2, organic semiconductor, heterostructure, charge transport, electronic properties, 2D crystal, 2D crystal transfer, tunneling.
Published in RUNG: 24.10.2022; Views: 797; Downloads: 31
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9. Carbon nanoparticles assisted energy transport mechanism in leaves: A thermal lens studySwapna Mohanachandran Nair Sindhu, 2019, original scientific article Abstract: In the world of increasing population and pollution due to carbon emissions, the research for effective utilization of futile diesel soot for fruitful applications has become a necessity for a sustainable development. The contribution to pollution from vehicles and industries due to the aging of engines has caused a crisis. Carbon nanoparticles (CNPs) have been the subject of interest because of their good physical, chemical, and biological properties. The present work investigates the role of CNPs produced by internal combustion engines on the energy transport mechanism among leaf pigments using the sensitive and nondestructive single beam thermal lens technique. The studies reveal the absorption changes by various chlorophyll pigments with the concentration of CNPs sprayed on the leaves. Though for low concentrations CNPs lower the photon absorbance by chlorophyll pigments, the effect gets reversed at higher concentrations. The variation of thermal diffusivity with CNP concentration and its role in the energy transport mechanism among chlorophyll pigments are also studied. It is found that CNP concentrations of 625-2500mg/l are good for better intra-pigment energy transport leading to increased rate of photosynthesis and plant yield and thereby helping in attaining food security. The variation of CNP assisted energy transport among leaf pigments on the production of nicotinamide adenine dinucleotide phosphate (NADPH) and carbohydrates is also studied with ultraviolet (UV) and near-infrared (NIR) spectroscopy.
Keywords: carbon nanoparticle, soot, energy transport, thermal lens, photosynthesis
Published in RUNG: 05.07.2022; Views: 686; Downloads: 0
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10. Charge transport characterization of P3HT thin-film organic semiconductor : Written report: in fulfilment of diploma seminar 1FAF29 requirementMatija Filipčič, 2021, research project (high school) Abstract: The focus of this diploma seminar is to describe different types of charge transport theory and
models used for finding mobility in semiconductors, more specifically focused on P3HT thin-film
organic semiconductor. It also describes the time-of-flight method, which was used to measure the
experimental data for P3HT with time dependent current I(t) curve. Another data set was obtained
by performing Kinetic Monte Carlo (KMC) simulations using Miller-Abrahams hopping formalism.
KMC was used to determine the material disorder, simulate I(t) curve and transit time for every
charge carrier. Simulated data, different transit times and mobilities were then finally compared
with experimental, in order to find agreements between the two.
Keywords: charge transport, P3HT, thin-film organic semiconductor
Published in RUNG: 15.09.2021; Views: 1683; Downloads: 0
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