Search results for "ISMU"
showing 10 items of 685 documents
Spoguļi un gaismu atstarojošas virsmas interjerā
2017
Diplomdarbā “Spoguļi un gaismu atstarojošas virsmas interjerā”, analizējot pieejamo literatūru, tīmeklī esošo informāciju un mēbeļu un buvmateriālu ražotāju piedāvātus materiālus, tiek pētīts jēdziens “gaismu atstārojošās virsmas” un “spogulis”, ka arī gaismu atstārojošu virsmu nepieciešamība un to ietekme projektējot interjeru. Empīriskajā daļā tiek petīti privātie un sabiedriskie interjeri, īpašu uzmanību pieveršot skaistumkopšanas saloniem Latvijā un ārvalstīs. Radošajā daļā, pielietojot ieģutas zināšanas, tiek izstrādāts interjera dizaina projekts skaistumkopšanas salonam. Darbs sastāv no trīs nodaļām: pirmajā nodaļā tiek pētīta spoguļu rašanas vēsture un to evolūcija; otrajā nodaļā - s…
Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination.
2022
Funder: AiF Project, no: ZIM-KK5085302DF0
Nanowires for NEMS Switches
2020
Nanoelectromechanical systems (NEMS) are a promising novel technology for operation in extreme conditions (e.g. high temperature and radiation levels), where complementary semiconductor technology devices might fail due to electronic instability. An example for a NEMS device is a nanowire-based switch, which employs mechanical deflection of a nanowire to open and close an electrical circuit. To date, assembly and operation of individual nanowire based NEMS switches have been successfully demonstrated at laboratory level, but their further technological development remains a challenge. This chapter gives an insight into the current advances in applications of nanowires for NEMS switches. Syn…
Bismuta un antimona halkogenīdu / oglekļa nanocaurulīšu heterostruktūru sintēze, īpašības un pielietojumi lokanās termoelektriskās ierīcēs
2021
Uz lokanu vadošo polimēru nanokompozītu bāzes veidoti termoelektriskie ģeneratori ir viens no perspektīvākajiem valkājamu elektrisko ierīču enerģijas avotiem. Tomēr šo ģeneratoru izveidei problēmas galvenokārt sagādā n-tipa strāvu vadošo polimēru zemā stabilitāte. Šajā darbā tika izveidoti termoelektriskie nanokompozīti un ģenerators uz strāvu nevadošu polimēru bāzes kā veiksmīga alternatīva nanokompozītiem, kas veidoti no strāvu vadošajiem polimēriem. Par termoelektrisko pildvielu tika izmantotas Bi2Se3 un Sb2Te3 un oglekļa nanocaurulīšu (CNT) heterostruktūras, kuru īpašības pēdējā laikā arvien biežāk piesaista pētnieku uzmanību arī citur pasaulē. Bi2Se3 un Sb2Te3 nanostruktūras tika sinte…
Catalyst-free vapour-solid technique for deposition of Bi2Te3 and Bi2Se3 nanowires/nanobelts with topological insulator properties.
2015
We present a simple two-stage vapour–solid synthesis method for the growth of bismuth chalcogenide (Bi2Te3, Bi2Se3) topological insulator nanowires/nanobelts by using Bi2Se3 or Bi2Te3 powders as source materials. During the first stage of the synthesis process nanoplateteles, serving as “catalysts” for further nanowire/nanobelt growth, are formed. At a second stage of the synthesis, the introduction of a N2 flow at 35 Torr pressure in the chamber induces the formation of free standing nanowires/nanobelts. The synthesised nanostructures demonstrate a layered single-crystalline structure and Bi : Se and Bi : Te ratios 40 : 60 at% for both Bi2Se3 and Bi2Te3 nanowires/nanobelts. The presence of…
Mechanism of Reaction of Melatonin with Human Myeloperoxidase
2001
Recently, it was suggested that melatonin (N-acetyl-5-methoxytryptamine) is oxidized by activated neutrophils in a reaction most probably involving myeloperoxidase (Biochem. Biophys. Res. Commun. (2000) 279, 657-662). Myeloperoxidase (MPO) is the most abundant protein of neutrophils and is involved in killing invading pathogens. To clarify if melatonin is a substrate of MPO, we investigated the oxidation of melatonin by its redox intermediates compounds I and II using transient-state spectral and kinetic measurements at 25 degrees C. Spectral and kinetic analysis revealed that both compound I and compound II oxidize melatonin via one-electron processes. The second-order rate constant measur…
Mass measurement of cooled neutron-deficient bismuth projectile fragments with time-resolved Schottky mass spectrometry at the FRS-ESR facility
2005
Masses of 582 neutron-deficient nuclides ($30\leq{Z}\leq{85}$) were measured with time-resolved Schottky mass spectrometry at the FRS-ESR facility at GSI, 117 were used for calibration. The masses of 71 nuclides were obtained for the first time. A typical mass accuracy of 30 $\mu$u was achieved. These data have entered the latest atomic mass evaluation. The mass determination of about 140 additional nuclides was possible via known energies ($Q$-values) of $\alpha-$, $\beta-$, or proton decays. The obtained results are compared with the results of other measurements.
Development of a liquid Pb-Bi target for high-power ISOL facilities
2016
Abstract This paper describes some R&D activities conducted in support of the design and safe operation of a high-power liquid Pb-Bi target within the LIEBE (Liquid Eutectic Lead Bismuth Loop Target for EURISOL) project. The target material is lead bismuth eutectic (LBE) which also acts as a primary coolant. As a consequence of interaction of the highly pulsed 1.4-GeV protons at ISOLDE with the target, heat powers of the order of 2 GW would be instantaneously deposited in the target during a bunch. Considerable R&D effort is thus required to demonstrate its continued coolability and structural integrity. This paper mainly reports on the conjugate flow (CFD) and heat deposition (Monte Carlo)…
The nuclear magnetic moment of 208Bi and its relevance for a test of bound-state strong-field QED
2018
Physics letters / B 779, 324 - 330 (2018). doi:10.1016/j.physletb.2018.02.024
The πd scattering length from Kα X-rays
1974
Abstract X-rays from the K α transition (2P → 1S) of the π − d mesic atom have been observed. Their energy, 2592.8 −2.0 +1.6 , has been measured by the critical absorber technique, using the M V absorption edge in bismuth. The strong interaction shift in the 1S state is −4.8 eV, corresponding to a scattering length a ( π d) = −(0.052 −0.017 +0.022 ) m π −1 , in agreement with recent calculations. The intensity ratio K α /K total = 0.548 ± 0.015.