Search results for "Fotoni"
showing 10 items of 37 documents
Compact Cell Imaging Device (CoCID) provides insights into the cellular origins of viral infections
2021
The overall CoCID concept is centred on providing virologists with a next-generation imaging device, which, through increased penetration and depth of focus, as well as through high natural contrast and sensitivity to organelle density (including virus-related organelles), will produce higher-fidelity ultrastructural images of whole intact cells. These insights will, in turn, help increase our understanding of the links between the structural reorganisation of cells and the mechanisms of viral entry, replication, assembly, and egress in cells. CoCID will provide this valuable imaging capability in the form of a compact lab-scale device that will greatly improve the accessibility of soft X-r…
On the carrier of inertia
2018
A change in momentum will inevitably perturb the all-embracing vacuum, whose reaction we understand as inertia. Since the vacuum's physical properties relate to light, we propose that the vacuum embodies photons, but in pairs without net electromagnetic fields. In this physical form the free space houses energy in balance with the energy of matter in the whole Universe. Likewise, we reason that a local gravitational potential is the vacuum in a local balance with energy that is bound to a body. Since a body couples to the same vacuum universally and locally, we understand that inertial and gravitational masses are identical. By the same token, we infer that gravity and electromagnetism shar…
Zvaigžņotā Debess: 2011, Vasara (212)
2011
Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: A.Balklavs. Extremely Distant New Objects of Metagalaxy (abridged) ; Newspaper „Literaturnaja Rossija” 9 April 1971. Astronautics: Yesterday, Today, Tomorrow (abridged) ; CONFERENCE “The VIEW from SPACE. FIRST MANNED SPACE FLIGHT – 50”: M.Gills. Conference on the Eve of Human Space Flight Anniversary ; J.Ekmanis, S.Negrejeva. Mstislav Keldysh and Golden Age of Soviet Science ; T.Millers. Contribution of Scientists of the Institute of Inorganic Chemistry to the Development of Space Technologies and Materials ; G.Vilka. Remembrance of Friedrich Zander in Rīga ; O.Plepis. My Contribution to the Development of Space Medicine ; J.Stradiņš. Latvia’s …
Hard diffraction in photoproduction with Pythia 8
2019
We present a new framework for modeling hard diffractive events in photoproduction, implemented in the general purpose event generator Pythia 8. The model is an extension of the model for hard diffraction with dynamical gap survival in pp and ppbar collisions proposed in 2015, now also allowing for other beam types. It thus relies on several existing ideas: the Ingelman-Schlein approach, the framework for multiparton interactions and the recently developed framework for photoproduction in gamma p, gamma gamma, ep and $e^+e^-$ collisions. The model proposes an explanation for the observed factorization breaking in photoproduced diffractive dijet events at HERA, showing an overall good agreem…
Ādas fulorescences un izkliedes kinētikas mērījumi pikosekunžu lāzera ierosmē
2017
Lai gan pirmajā acu uzmetienā ādas autofluorescence un starojuma izkliedes kinētikas ir it kā vienkāršas metodes vides pētīšanai un tās parametru noteikšanai, tieši tāpēc tās ir efektīvas. Izmantojot ādas veidojumu raksturošanai metodes, kas nav nepamatoti sarežģītas, iespējams iegūt lielumus, kas raksturo dažādas ādas pataloģijas. Fotonu uzvedības ādā apraksts ir svarīga sastāvdaļa optiskās diagnostikas attīstībai. Darbā tika pētīti ādas veidojumi, izmantojot autofluroescences mērījumus un fotona lidojuma laika ādā mērījumus. Tika iegūti vairāki parametri, ar ko raksturot dažādas ādas pataloģijas, kā arī apskatīta korelācija starp autofluroescenci un fotona lidojuma laika ādā raksturlielum…
Massive quarks in NLO dipole factorization for DIS : Transverse photon
2022
We calculate the light cone wave functions for the QCD Fock components in a transverse virtual photon necessary for applications at next-to-leading order in the QCD coupling, including quark masses. We present a detailed calculation of both the one loop wave function for the quark-antiquark Fock component and the tree level wave function for the quark-antiquark-gluon Fock component. The quark masses are renormalized in the pole mass scheme, satisfying constraints from the requirement of Lorentz invariance. In particular the quark Pauli form factor at NLO is recovered from the on-shell limit of the quark-antiquark Fock component. We use our result to calculate the next-to-leading order corre…
Merger of dark matter axion clumps and resonant photon emission
2020
A portion of light scalar dark matter, especially axions, may organize into gravitationally bound clumps (stars) and be present in large number in the galaxy today. It is therefore of utmost interest to determine if there are novel observational signatures of this scenario. Work has shown that for moderately large axion-photon couplings, such clumps can undergo parametric resonance into photons, for clumps above a critical mass $M^{\star}_c$ determined precisely by some of us in Ref. [1]. In order to obtain a clump above the critical mass in the galaxy today would require mergers. In this work we perform full 3-dimensional simulations of pairs of axion clumps and determine the conditions un…
Zvaigžņotā Debess: 2015, Rudens (229)
2015
Latvijas Universitāte
Microwave photoassisted dissipation and supercurrent of a phase-biased graphene-superconductor ring
2021
Irradiating normal-superconducting junctions with microwave photons produce spectacular effects, such as Shapiro steps and photoinduced modifications of the dc supercurrent. Moreover, microwave irradiation can also have other, hitherto unexplored consequences, such as a photoassisted dissipation which is phase dependent. Here we present a finite-frequency measurement of both the dissipation and the supercurrent of a phase-biased graphene-superconductor junction in response to microwave photons. We find that, while the supercurrent response is well described by existing theory, the dissipation exhibits unexpected effects which need new theoretical elucidation. Especially with high frequency …
Direct photon production at low transverse momentum in proton-proton collisions at √s = 2.76 and 8 TeV
2019
Measurements of inclusive and direct photon production at midrapidity in pp collisions at √s=2.76 and 8 TeV are presented by the ALICE experiment at the LHC. The results are reported in transverse momentum ranges of 0.47 GeV/c is at least one σ above unity and consistent with expectations from next-to-leading order pQCD calculations. peerReviewed