100 research outputs found
Nella biblioteca di Hartmann Schedel: l'index librorum aldino del 1498 e le Decades rerum Venetarum di Marcantonio Sabellico
No full textThe contribution examines the first catalogue issued by Aldo Manuzio on 1 October 1498 and in particular the copy in the Österreichische Nationalbibliothek in Vienna (Ink. 7.A.13). A careful examination of the manuscript annotations, known to be by Hartmann Schedel, has enabled the author to identify the volume in which Schedel had the catalogue bound in his lifetime: a copy of Marcantonio Sabellico’s Decades rerum Venetarum (Venice, Andrea Torresani, 1487) also in the Österreichische Nationalbibliothek (Ink. 7.A.7). A detailed description of the item and Schedel's textual and graphic additions reveals for the first time what was one of the most significant books in the humanist's library and allow us to reconstruct the overall context of its use in the years immediately following its publication
STUDY OF THE ELECTRONIC GROUND STATE OF BY LASER EXCITED FLUORESCENCE FOURIER TRANSFORM SPECTROSCOPY
No full text C. Jungen, K-E.J. Hallin and A.J.Merer, Molec. Phys., 40, 25 (1980). G. Duxbury and R.N. Dixon, Molec. Phys., 43, 255 (1981). M. Peric, S.D. Peyerimhoff and R.J. Buenker, Molec.Phys. 49, 379 (1983).Author Institution: Herzberg Institute of Astrophysics, National Research Council of CanadaA large number of spin-rovibronic levels of the upper electronic state of have been excited with a single mode rhodamine 6G dye laser. Fluorescence spectra were obtained over a wide spectral range (12000-3700 cm-1) using a Fourier transform spectrometer. Levels of the bending vibration were observed from up to 10, showing the reordering of the K-structure at the barrier to linearity: their observed energies are in good agreement with the predictions of Jungen, Hallin and Merer1 , Duxbury and and Peric, Peyerimhoff and . Numerous vibrational levels involving and were also detected and approximate anharmonic parameters have been deduced
»Der Aufsatz […] war gar nicht so ›sexy‹ wie das Bild.«: Fotografien weiblicher Körper in der DDR-Zeitschrift "Das Magazin" in den 1950er Jahren
No full textTThe present essay features Das Magazin, a popular East German monthly magazine that appeared in the GDR for the first time in 1954. The author analyzes the photographic depiction of women in issues of the 1950s. This analysis starts with the magazine’s prominent and well-researched nude photographs, but later focuses on other images of female bodies, i.e. in photo montages, to explore the different variations in which women were depicted in Das Magazin. A close examination of the images in question, their position and contextualization within Das Magazin allows for a look beyond the pages of the printed product and sheds light on the work of the layout artists. In doing so, the author argues that its creators revived certain visual strategies that had already been cultivated by the popular press in the interwar period and which were also existent beyond the boundaries of the GDR press. Thus, the notion of GDR magazines’ production practices can be enriched by transnational and historical perspectives.The present essay features Das Magazin, a popular East German monthly magazine that appeared in the GDR for the first time in 1954. The author analyzes the photographic depiction of women in issues of the 1950s. This analysis starts with the magazine’s prominent and well-researched nude photographs, but later focuses on other images of female bodies, i.e. in photo montages, to explore the different variations in which women were depicted in Das Magazin. A close examination of the images in question, their position and contextualization within Das Magazin allows for a look beyond the pages of the printed product and sheds light on the work of the layout artists. In doing so, the author argues that its creators revived certain visual strategies that had already been cultivated by the popular press in the interwar period and which were also existent beyond the boundaries of the GDR press. Thus, the notion of GDR magazines’ production practices can be enriched by transnational and historical perspectives
Re-collision times of a nitroxide spin probe in alkane solvents
No full textThe bimolecular re-encounter time r D of a nitroxide spin probe is measured using electron paramagnetic resonance (EPR) spectroscopy for three n-alkane solvents. Experimental determination of r D requires independent measurement of two quantities, namely, the spectral line shift and line broadening. For the solvent with the smallest molecular volume, fair agreement is found between measured values of r D and the predictions of Stokes-Einstein hydrodynamic theory, a model which holds in the limit of large probe-to-solvent volume ratio. Using the experimental values of r D, probe velocities are computed based upon the assumed existence of interstitial cavities within each solvent, and these velocities are found to be of the same order of magnitude as mesoscopic probe velocities predicted from classical hydrodynamic theory. Re-encounter times in all solvents appear to form a common curve when plotted against solvent isothermal compressibility, thereby raising the prospect of using EPR to determine the compressibility not only of other substances but also that of biological membranes. Also, the observed values of Tn itself are of the same order of magnitude as the equilibrium lifetimes predicted by hydrodynamic theory, which is to be expected of a collision pair that is jointly occupying a local equilibrium region. It is found that correction factors borrowed from rotational-diffusion theory may have applicability to theoretically predicting probe re-encounter times due to the fact that both phenomena are governed by the same local conditions within interstitial spaces. The re-encounter component of spin exchange is compared to the overall spin-exchange and the two are found to differ fundamentally in their behavior with respect to certain properties of the solvent.Includes bibliographical references (leaves 43-45)California State University, Northridge. Department of Physics and Astronomy
Molecular and functional characterisation of the zebrafish (Danio rerio) PEPT1-type peptide transporter
No full textWe report the molecular and functional characterisation of a novel peptide transporter from zebrafish, orthologue to mammalian and avian PEPT1. Zebrafish PEPT1 is a low-affinity/high-capacity system. However, in contrast to higher vertebrate counterparts in which maximal transport activity is independent of extracellular pH, zebrafish PEPT1 maximal transport rates unexpectedly increase at alkaline extracellular pH. Zebrafish pept1 is highly expressed in the proximal intestine since day 4 post-fertilisation, thus preceding functional maturation of the gut, first feeding and complete yolk resorption. Zebrafish PEPT1 might help to understand the evolutionary and functional relationships among vertebrate peptide transporters. Moreover, zebrafish pept1 can be a useful marker for screening mutations that affect gut regionalisation, differentiation and morphogenesis
Betrachten, Blättern, Enthüllen, Lauschen, Lesen.: Walter Scotts »THE TAPESTRIED CHAMBER«, das KEEPSAKE FOR MDCCCXXIX, sein zehnter Stahlstich und ihr interaktives Bedeutungsangebot
No full textThis article deals with the aesthetic effects that arise when reading, viewing and handling different media formats. It takes strongly divergent contemporary evaluations of a well-known gothic tale by Walter Scott, »THE TAPESTRIED CHAMBER«, as an opportunity to investigate the medial and material causes of these differences. The author concentrates on the first publication of the tale in autumn 1828 in the opulent annual gift book THE KEEPSAKE FOR MDCCCXXIX, with its numerous steel engravings, and on another early print of the text in the magazine THE OLIO, OR, MUSEUM OF ENTERTAINMENT, with its wood-engraved illustrations. Both prints organise the reading of »THE TAPESTRIED CHAMBER« in specific ways, each setting in motion specific processes of understanding, each stimulating specific aesthetic experiences. This can be traced back in particular to the illustrations placed alongside the prints of the narrative text, to their production, reproduction and presentation in the printed product, to the way in which they are integrated into the flow of reception, which senses of the recipients they address and to which specific forms of media interaction they invite.This article deals with the aesthetic effects that arise when reading, viewing and handling different media formats. It takes strongly divergent contemporary evaluations of a well-known gothic tale by Walter Scott, »THE TAPESTRIED CHAMBER«, as an opportunity to investigate the medial and material causes of these differences. The author concentrates on the first publication of the tale in autumn 1828 in the opulent annual gift book THE KEEPSAKE FOR MDCCCXXIX, with its numerous steel engravings, and on another early print of the text in the magazine THE OLIO, OR, MUSEUM OF ENTERTAINMENT, with its wood-engraved illustrations. Both prints organise the reading of »THE TAPESTRIED CHAMBER« in specific ways, each setting in motion specific processes of understanding, each stimulating specific aesthetic experiences. This can be traced back in particular to the illustrations placed alongside the prints of the narrative text, to their production, reproduction and presentation in the printed product, to the way in which they are integrated into the flow of reception, which senses of the recipients they address and to which specific forms of media interaction they invite
Micro-scale cavities in the slip - and transition - flow regimes
No full textDifferences between Navier-Stokes-Fourier (NSF) slip/jump solutions and direct simulation Monte-Carlo (DSMC) computations are highlighted for a micro lid-driven cavity problem. The results indicate a need for better modelling techniques which at the same time retain low computational cost of NSF models. We also highlight the fact thatmany micro-flows that have been considered are simple planar flows and typical classification systems are defined on such flows. We show that for complex flows, such as thedriven cavity, non-equilibrium effects are more appreciable and their onset occurs at lower Knudsen numbers than expected
Using Cherenkov radiation to measure the power of a nuclear reactor in steady-state and pulsed operation
No full textV večini vodno hlajenih jedrskih reaktorjev je med obratovanjem prisotna Čerenkova svetloba. Predvsem pri reaktorjih bazenskega tipa, med katere spada tudi reaktor TRIGA Mark II na Institutu \u27\u27Jožef Stefan\u27\u27, je Čerenkova svetloba vidna s prostim očesom kot modri sij okrog sredice. Nastane kot posledica visokoenergijskih nabitih elektronov, ki potujejo skozi hladilo hitreje od hitrosti svetlobe v mediju. Meritev intenzitete Čerenkove svetlobe predstavlja osnovo pri preverjanju izrabljenosti goriva v bazenih za izrabljeno gorivo. V okviru obratovanja jedrskega reaktorja pa lahko meritev intenzitete Čerenkove svetlobe z nekaterimi omejitvami predstavlja redundantno meritev moči.
V začetku naloge je predstavljeno fizikalno ozadje nastanka Čerenkove svetlobe. Sledijo principi delovanja silicijeve fotopomnoževalke, ki je bila izbrana kot detektor intenzitete svetlobe v okviru razvoja merilnika moči jedrskega reaktorja na podlagi Čerenkove svetlobe. Faze v razvoju merilnika so predstavljene in podprte z meritvami opravljenimi na reaktorju IJS TRIGA Mark II. Spektralne meritve in meritev intenzitete svetlobe v merilnem kanalu predstavljajo osnovo za izbiro komponent merilnega sistema. V okviru razvoja so nastali trije merilniki moči jedrskega reaktorja na podlagi svetlobe Čerenkova, ki so na koncu poglavja \u27\u27Razvoj in postavitev merilnega sistema\u27\u27 primerjani med sabo.
Razviti merilnik imenovan \u27\u27Nadgrajeni merilnik intenzitete Čerenkove svetlobe\u27\u27 je bil dodobra preizkušen tako pri stacionarnem kot tudi pri pulznem delovanju jedrskega reaktorja. Vse opravljene meritve so bile primerjane z meritvami iz obstoječe jedrske instrumentacije in Fuchs-Hansen-ovim teoretičnim modelom. Iz primerjav je razvidno, da razviti merilnik deluje v skladu s snemalnikom pulzov jedrskega reaktorja, vendar z večjim dinamičnim razponom. Razviti merilnik omogoča vpogled v potek moči jedrskega reaktorja v območju nižjih pulzov, kar snemalnik pulzov v okviru jedrske instrumentacije ne omogoča. Ujemanje izmerjenih fizikalnih parametrov pulza s teoretičnim modelom je odlično. V primeru stacionarnega obratovanja reaktorja, pa je delovanje obstoječe jedrske instrumentacije boljše v primerjavi z razvitim merilnikom. V zaključku so predstavljene možnosti nadgradnje razvitega sistema v luči boljšega delovanja in pridobljeni rezultati v okviru opravljenega raziskovalnega dela.Cherenkov radiation is present in most water-cooled nuclear reactors. Especially in the case of pool-type reactors, including the TRIGA Mark II reactor at the \u27\u27Jožef Stefan\u27\u27 Institute, Cherenkov light is visible as a blue glow around the reactor core. It is due to energetic charged electrons traveling faster than the speed of light in a dielectric medium. Cherenkov light intensity measurements are the basis for verification of spent nuclear fuel in spent-fuel pools for nuclear safeguards. During nuclear reactor operation, the measurement of the Cherenkov light intensity may, with some limitations, represent a possibility for reactor power monitoring.
This work presents the physics of Cherenkov radiation, its production in nuclear reactors and the working principles of silicon photomultipliers. A Cherenkov light based nuclear reactor power meter is presented. Its development for the \u27\u27Jožef Stefan\u27\u27 Institute TRIGA reactor is described. Spectral measurements and the measurement of light intensity in the measurement channel represent the basis for the selection of components of the developed measurement system. During the development three nuclear reactor power meters based on Cherenkov light were created. They are compared with each other at the end of the chapter \u27\u27Development and setup of the measuring system\u27\u27.
All measurements were compared with the Fuchs-Hansen theoretical model and measurements performed by reactor\u27s nuclear instrumentation. The developed meter named \u27\u27Upgraded Cherenkov Light Intensity Meter\u27\u27 has been thoroughly tested in both stationary and pulsed operation of the nuclear reactor. It is clear that the developed meter works in accordance with the pulse recorder of the nuclear reactor, but with a larger dynamic range. It allows insight into lower pulses, which is not possible with the pulse recorder, part of the nuclear instrumentation. The measured physical parameters of the pulse agree well with the theoretical model. In the case of stationary operation of the reactor, the performance of the existing nuclear instrumentation is better compared to the developed meter. In conclusion, possible upgrades of the developed system and obtained results are presented
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