Search results for "Smut"
showing 10 items of 493 documents
Slāņainu grafēns/Bi2Se3 struktūru sintēze
2016
Darbā uz elektroķīmiski pulētām vara pamatnēm tika sintezēts ķīmisko tvaiku nogulsnēts grafēns. Optimizēta grafēna pārnešanas procedūra, veicot grafēna pārnešanas procesā izmantotā poli(metilmetakrilāta) šķīdināšanu etiķskābes šķīdumos. Tika pārbaudīta grafēna kvalitāte pirms un pēc pārnešanas uz nevadošam pamatnēm izmantojot Ramana spektroskopiju, elektrovadītspējas mērījumiem un apskati skenējošā elektronu mikroskopā. Darbā ir izstrādāta horizontālu un dažādos leņķos orientētu bismuta selenīda nanostruktūru uz grafēna virsmas sintēzes metode. Ir noteikts iegūto slāņaino grafēns/Bi2Se3 struktūru termoelektriskais un fotoelektriskais efekts.
Dopētu un nedopētu bismuta selenīda nanolaminātu veidošana un raksturošana
2019
Dopētu un nedopētu bismuta selenīdu nanolaminātu veidošana un raksturošana. Britāla L., zinātniskie vadītāji Dr. phys., vadošā pētniece Andžāne J., Dr. chem., asoc. prof. Erts D. Bakalaura darbs, -- lappuses, -- attēli, -- tabulas, -- literatūras avoti, -- pielikumi. Latviešu valodā. Šajā pētījumā tiek izstrādāta metode ar alvu dopētu un nedopētu Bi2Se3 ultraplānu kārtiņu, ar biezumu 10 nm, sintēzei uz grafēna virsmas. Secīgi sintezējot šādi strukturētus bismuta selenīda slāņus, uz grafēna pamatnes tiek izveidots nanolamināts, kurš sastāv no dopētām un nedopētām ultraplānām bismuta selenīda kārtiņām. Noteiktas šo nanolaminātu termoelektriskās īpašības un tos ietekmējošie faktori.
Genetic manipulation of longevity-related genes as a tool to regulate yeast life span and metabolite production during winemaking
2013
Abstract Background Yeast viability and vitality are essential for different industrial processes where the yeast Saccharomyces cerevisiae is used as a biotechnological tool. Therefore, the decline of yeast biological functions during aging may compromise their successful biotechnological use. Life span is controlled by a variety of molecular mechanisms, many of which are connected to stress tolerance and genomic stability, although the metabolic status of a cell has proven a main factor affecting its longevity. Acetic acid and ethanol accumulation shorten chronological life span (CLS), while glycerol extends it. Results Different age-related gene classes have been modified by deletion or o…
Le sérieux du jeu : le concept du jeu gadamérien et son rôle dans l’expérience de l’art et de la vérité
2018
National audience
Fabrication of Bismuth Absorber Arrays for NTD-Ge Hard X-ray Microcalorimeters
2020
The high-spectral-resolution detection of hard X-rays (E > 20 keV) is a challenging and nearly unexplored area in space astrophysics. Traditionally hard X-ray detectors present moderate spectral resolutions, although few tens of eV one could open new frontiers in the study of nuclear processes and high-temperature plasma dynamics in energetic processes. This can be achieved by using cryogenic microcalorimeters. Within a research activity aimed at developing arrays of neutron transmutation-doped germanium (NTD-Ge) microcalorimeters for the high-spectral-resolution detection (about 50 eV@60 keV) of hard X-rays (20 keV < E<100 keV), we developed an electroplating process to fabricate …
Neutron cross section measurements at n_TOF for ADS related estudies
2005
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main res…
Quantum size effect in single-crystalline bismuth nanorods
2017
Impedance and admittance characteristics of Bi2S3 nanowire arrays
2013
Current studies of the electrical impedance and admittance characteristics of the anodised aluminum oxide (AAO) nanoporous arrays and bismuth sulphide (Bi2S3) nanowire within AAO membranes are presented. The influence of potential and frequency scan rate effect produced on the real, imaginary and complex electrochemical impedance and double layer capacitance of the AAO nanopore and the Bi2S3 nanowire arrays were studied.
Lifetimes and g-factors of the HFS states in H-like and Li-like bismuth
2018
The LIBELLE experiment performed at the experimental storage ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany, has successfully determined the ground state hyperfine (HFS) splittings in hydrogen-like ($^{209}\rm{Bi}^{82+}$) and lithium-like ($^{209}\rm{Bi}^{80+}$) bismuth. The study of HFS transitions in highly charged ions enables precision tests of QED in extreme electric and magnetic fields otherwise not attainable in laboratory experiments. Besides the transition wavelengths the time resolved detection of fluorescence photons following the excitation of the ions by a pulsed laser system also allows to extract lifetimes of the upper HFS levels and g-fac…
Laser spectroscopy measurement of the 2s-hyperfine splitting in lithium-like bismuth
2017
We have recently reported on the first direct measurement of the $2s$ hyperfine transition in lithium-like bismuth (209Bi80+) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. Combined with a new measurement of the $1s$ hyperfine splitting (HFS) in hydrogen-like (209Bi82+) the so-called specific difference ${\rm{\Delta }}^{\prime} E=-61.37(36)$ meV could be determined and was found to be in good agreement with its prediction from strong-field bound-state quantum electrodynamics. Here we report on additional investigations performed to estimate systematic uncertainties of these results and on details of the experimental setup. We show that the dominating uncertainty a…