Search results for "PIE"

Development of LIBS for online analysis of solid nuclear materials

2015

With the objective to implement a fast, online analysis technique for control of solid metal nuclear materials, laser-induced breakdown spectroscopy (LIBS) technique is developed for quantitative analysis in uranium and plutonium. Since these matrices have a very dense emission spectrum in the UV-Visible range, the Vacuum Ultra-Violet (VUV) spectral range, less rich in lines, is explored. The aim of this thesis is to perform the analytical development of VUV-LIBS for quantitative analysis between 500 and 5000 ppm with an uncertainty of 3%. For that purpose, four steps were defined. First, for practical and safety reasons, it is generally better to perform experiments on surrogate materials.…

Pēc 5 mirkļiem 100 gadi: bibliotēku dārgumi : izstādes buklets

2014

Reto izdevumu un manuskriptu izstāde BIBLIOTĒKU DĀRGUMI ir Latvijas Universitātes Bibliotēkas un Latvijas Universitātes Akadēmiskās bibliotēkas veltījums Latvijas Universitātei 95. gadadienā

Akadēmiskā Dzīve, Nr. 50

2014

Informācijas uztveres uzlabojumu eksperimentāla testēšana mobilajās lietotnēs cilvēkiem ar redzes teraucējumiem

2022

Viedtālruņi ir neatņemama ikdienas sastāvdaļa arvien vairāk cilvēkiem, daļai no tiem esot cilvēkiem ar redzes traucējumiem. Lai gan izstrādātājiem ir pieejami informācijas uztveramības uzlabošanas ieteikumi, noteikumi un vadlīnijas, piekļūstamība mobilajās lietotnēs vēl joprojām ir zema. Darba mērķis ir apkopot efektīvus informācijas uztveres uzlabošanas risinājumus. Pētījumā tika atrasti desmit biežāk izmantotie risinājumi, izpētīts zinātniskais vai GMD vadlīniju pamatojums to pielietošanai un eksperimentā izpētīts, cik efektīvs ir katrs no risinājumiem. Analizējot eksperimenta rezultātus, risinājumi tika iedalīti trīs kategorijās- 6 uztveri uzlabojoši, 2 neietekmējoši un 1 pasliktinošs. P…

A study of the effect of molecular and aerosol conditions in the atmosphere on air fluorescence measurements at the Pierre Auger Observatory

2010

The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierr…

Production and detection of atomic hexadecapole at Earth's magnetic field

2007

Anisotropy of atomic states is characterized by population differences and coherences between Zeeman sublevels. It can be efficiently created and probed via resonant interactions with light, the technique which is at the heart of modern atomic clocks and magnetometers. Recently, nonlinear magneto-optical techniques have been developed for selective production and detection of higher polarization moments, hexadecapole and hexacontatetrapole, in the ground states of the alkali atoms. Extension of these techniques into the range of geomagnetic fields is important for practical applications. This is because hexadecapole polarization corresponding to the $\Delta M=4$ Zeeman coherence, with maxim…

Female reactions to male absence after pairing in the pied flycatcher

1994

Mating with an already mated pied flycatcher (Ficedula hypoleuca) male is costly for a female. Two hypotheses explain why some females still mate with already mated males. The deception hypothesis suggests that some females mate with already mated males since it is difficult to assess perfectly the mating status of a male with separate territories (polyterritoriality). The search cost hypothesis states that females are aware of male mating status but the costs of searching for an unmated male exceed costs associated with the status of secondary female. One potential cue that could disclose a male's mating status is the existence of brief visits to the primary territory by polyterritorial ma…

Contribution of sponge genes to unravel the genome of the hypothetical ancestor of Metazoa (Urmetazoa)

2001

Recently the term Urmetazoa, as the hypothetical metazoan ancestor, was introduced to highlight the finding that all metazoan phyla including the Porifera (sponges) are derived from one common ancestor. Sponges as the evolutionarily oldest, still extant phylum, are provided with a complex network of structural and functional molecules. Analyses of sponge genomes from Demospongiae (Suberites domuncula and Geodia cydonium), Calcarea (Sycon raphanus) and Hexactinellida (Aphrocallistes vastus) have contributed also to the reconstruction of the evolutionary position of Metazoa with respect to Fungi. Furthermore, these analyses have provided evidence that the characteristic evolutionary novelties…

Poetiche della musica nell'antichità e nel rinascimento

2008

Tramite Aristosseno, Dionigi d'Alicarnasso e Pietro Bembo la poestica dell'antica musica ellenica del V secolo a.C. viene trasmessa ai compositori del madrigale polifonico italiano del Rinascimento.

Beads of Acryloylated Polyaminoacidic Matrices Containing 5-Fluorouracil for Drug Delivery

2002

Spherical polymeric microparticles have been prepared by a reverse phase suspension polymerization technique. The starting polymer was alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), partially derivatized with glycidylmethacrylate (GMA). PHEA-GMA copolymer (PHG) was crosslinked in the presence of N,N'-dimethylacrylamide (DMAA) or N,N'-ethylenebisacrylamide (EBA). 5-fluorouracil was incorporated into PHG-DMAA or PHG-EBA beads both during and after the crosslinking process. Swelling studies revealed a high affinity toward aqueous medium, influenced by the presence of 5-fluorouracil. The in vitro release study showed that the release rate depends on the chemical structure of the beads…