11 research outputs found
PROGRESS IN MATERIALS FOR MICROELECTRONICS AND FURTHER CHALLENGES
No full textDevelopment of materials and technologies for microelectronics is required by the needs of the constantly in-creasing level of integration of microelectronics circuits. Increase of the integration level compels downscaling of all the dimensions of devices, which in its turn requires very thin layers with exceptional quality due to rather high elec-tric fields at working conditions. First, technological improvements are adopted aimed at fabrication of materials with uniform quality, geometrical flatness and extremely low density of intentionally introduced defects. Second, new fab-rication methods are developed providing materials with much better quality. Third, new materials showing better properties than the standard (conventional) ones are obtained and developed further.Decreasing the dimensions of the layers changes the nature of the physical phenomena involved in the func-tioning of devices. Quantum mechanical mechanisms are more and more important in the description of the properties of the materials and devices on the nanoscale. The question arises where is the limit of the possibilities of the materi-als and technologies for nanoscale electronics.</jats:p
PESI - a taxonomic backbone for Europe
No full textThis is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The attached file is the published version of the article.NHM Repositor
Scrapie-infected cells, isolated prions, and recombinant prion protein: a comparative study
No full textFourier-transform infrared microscopic spectra of scrapie-infected nervous tissue measured at high spatial resolution (~6 micro m) were compared with those obtained from the purified, partly proteinase K digested scrapie isoform of the prion protein isolated from nervous tissue of hamsters infected with the same scrapie strain (263K) to elucidate similarities/dissimilarities between prion structure investigated in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP90-232 after in vitro conformational transition from the predominantly alpha -helical isoform to beta -sheet-rich structures. It is shown that prion protein structure can be investigated within tissue and that detectability of regions with elevated beta -sheet content as observed in microspectra of prion-infected tissue strongly depends on spatial resolution of the experiment..CF: 10th European Conference on the Spectroscopy of Biological Moleculres, 2003.; SC: 0V; 0I; CA; VE; ZA; XURL: URL; E-MAILSource type: Electronic(1)[email protected]; http://www3.interscience.wiley.com/cgi-bin/abstract/108067060/ABSTRACT; http://upei-resolver.asin-risa.ca?sid=SP:CABI&id=pmid:&id=&issn=0006-3525&isbn=&volume=74&issue=1%2f2&spage=163&pages=163-167&date=2004&title=Biopolymers%20&atitle=Scrapie-infected%20cells%2c%20isolated%20prions%2c%20and%20recombinant%20prion%20protein%3a%20a%20comparative%20study.&aulast=Kneipp&pid=%3Cauthor%3EKneipp%2c%20J%3bMiller%2c%20L%20M%3bSpassov%2c%20S%3bSokolowski%2c%20F%3bLasch%2c%20P%3bBeekes%2c%20M%3bNaumann%2c%20D%3C%2Fauthor%3E%3CAN%3E20063073521%3C%2FAN%3E%3CDT%3EJournal%20article%3bConference%20paper%3C%2FDT%3
Magnetization carriers of grey to red deep-water limestones in the GSSP of the Givetian–Frasnian boundary (Puech de la Suque, France): signals influenced by moderate diagenetic overprinting.
No full textCorresponding author (e-mail: [email protected])
Limestones at the Puech de la Suque Global Boundary Stratotype Section and Point (GSSP) of the Givetian–Frasnian boundary show a drastic change towards much higher magnetic susceptibility values in the Givetian rocks. Different rock magnetic parameters indicate that ferromagnetic minerals are the main controlling factor. The ferromagnetic fraction is composed of low- (magnetite-type) and high-coercivity (hematite and goethite) phases. Confirmed by the spectral reflectance, high coercivity minerals are fluctuating along the section with a higher abundance in the basal Frasnian. These phases may be of secondary origin and produced during burial stage. The magnetite-type phase contains two different grain-size populations. The identified that Stable Single-domain/Superparamagnetic (SSD/SP) particles are of diagenetic origin and their amount decreases slightly upwards. A second group of magnetite grains correspond to coarse-grained particles identified using the squareness v. coercive force plot. It is tentatively suggested here that these particles present throughout the section are of primary origin. On the contrary, the paramagnetic minerals underwent a clear diagenetic overprinting and may represent secondary minerals. The presence of a primary ferromagnetic carrier allowed the use of spectral analyses, leading to the detection of spectral peaks at 1.25 and 4 cycles/m, which can be interpreted as the result of 405-kyr and 100-kyr eccentricity forcing, respectively
Western Palaearctic palaeoenvironmental conditions during the Early and early Middle Pleistocene inferred from large mammal communities, and implications for hominin dispersal in Europe
No full textReceived 7 June 2010 / Received in revised form / 27 July 2010 / Accepted 28 July 2010 / Available online 28 September 2010.
© 2010 Elsevier Ltd. All rights reserved.
Corresponding author. E-mail address: [email protected] (R.-D. Kahlke).Large-scale fluctuations in global climate and resulting changes in ecology had a profound effect on human evolution and dispersal. Though hominin remains are scarce, studies focussing on the more abundant records of fossil land mammal communities can contribute greatly to our knowledge of the palaeoenvironmental circumstances that influenced and directed the global spread of hominins. To produce a comprehensive and accurate account of the evolution of western Palaearctic habitat diversity between 2.6 and 0.4 Ma BP, information generated from large mammal communities from 221 key sites has been included in this study.
The palaeoecological conditions of the western Palaearctic during the Early and early Middle Pleistocene were principally controlled by the following key factors: (1) a widespread trend of temperature decrease, (2) the periodicity of the global temperature record, (3) the intensity of single climatic stages, (4) the temporal pattern of climatic variation, (5) geographical position, and (6) the distribution of continental water resources. A general picture of the evolution of western Palaearctic habitat diversity saw the replacement of extensive forested terrain by an alternating sequence of varied savannah-like and forested habitats during the 2.6e1.8 Ma span, as well as an alternation between different types of predominantly open habitats between 1.8 and 1.2 Ma. Both of these processes were governed by 41 ka temperature periodicity. During the 1.2e0.9 Ma time span, irregular climatic fluctuations were more common and habitat variability increased. The subsequent 0.9e0.4 Ma interval, a period controlled by 100 ka periodicity, was by comparison more stable, with longer climatic cycles alternating between open and forested landscapes. During the entire Early and early Middle Pleistocene, assemblages of large mammal communities reveal a distinct trend of decreasing continentality between Eastern and South- Eastern Europe on the one hand, and South-Western and North-Western Europe on the other. This trend was due to the effect of the Atlantic Ocean, while in Southern Europe the relatively low continentality was balanced by influences from the Mediterranean Sea.
When plotted against evidence of hominin occurrence, the data on western Palaearctic habitat diversity inferred from large mammal communities indicate clear environmental stimuli for the earliest human dispersal in Europe. These are: (1) a wide range of habitats, implying a high diversity of resources; (2) mild climates with low seasonality, implying a lack of strong environmental fluctuations. Around 1.8 Ma at the latest, hominins of African origin entered the western Palaearctic for the first time, taking advantage of the diversity of habitats and resources, particularly along large river systems. Their subsequent westward spread between 1.7 and 1.3 Ma was restricted to Mediterranean-influenced areas, which offered a high variability of habitats and relatively low seasonality. The increase in environmental diversity, which occurred from 1.2 Ma onwards, opened up South-Eastern and Eastern Europe for hominin occupation. According to the available records, North-Western and Central Europe were initially colonized during late Early to early Middle Pleistocene interglacials, when these regions experienced periods of low seasonality and considerable habitat diversity.Ministerio de Ciencia e Innovación (España)Russian Foundation for Basic ResearchRussian Foundation for Basic ResearchDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu
Search for single top quark production via contact interactions at LEP2
No full textSingle top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were accumulated at centre-ofmass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1 pb−1. No evidence for a signal was found. Limits on the energy scale Λ, were set for scalar-, vector- and tensor-like coupling scenarios. © The Author(s) 2011
A study of the b-quark fragmentation function with the DELPHI detector at LEP I and an averaged distribution obtained at the Z Pole
No full textThe nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementarymethods are used to reconstruct the energy of weakly decaying b-hadrons, EweakB. The average value of xweakB = EweakB/Ebeam is measured to be 0.699 ± 0.011. The resulting xweakB distribution is then analysed in the framework of two choices for the perturbative contribution (parton shower and Next to Leading Log QCD calculation) in order to extract measurements of the non-perturbative contribution to be used in studies of bhadron production in other experimental environments than LEP. In the parton shower framework, data favour the Lund model ansatz and corresponding values of its parameters have been determined within PYTHIA 6.156 from DELPHI data: a=1.84+0.23-0.21 and b=0.642+0.073-0.063 GeV-2, with a correlation factor ρ=92.2%. Combining the data on the b-quark fragmentation distributions with those obtained at the Z peak by ALEPH, OPAL and SLD, the average value of xweakB is found to be 0.7092 ± 0.0025 and the non-perturbative fragmentation component is extracted. Using the combined distribution, a better determination of the Lund parameters is also obtained: a = 1.48+0.11-0.10 and b = 0.509+0.024-0.023 GeV-2, with a correlation factor ρ 92.6%. © The Author(s) 2011
Study of the dependence of direct soft photon production on the jet characteristics in hadronic Z0 decays
No full textAn analysis of the direct soft photon production rate as a function of the parent jet characteristics is presented, based on hadronic events collected by the DELPHI experiment at LEP1. The dependences of the photon rates on the jet kinematic characteristics (momentum, mass, etc.) and on the jet charged, neutral and total hadron multiplicities are reported. Up to a scale factor of about four, which characterizes the overall value of the soft photon excess, a similarity of the observed soft photon behavior to that of the inner hadronic bremsstrahlung predictions is found for the momentum, mass, and jet charged multiplicity dependences. However for the dependence of the soft photon rate on the jet neutral and total hadron multiplicities a prominent difference is found for the observed soft photon signal as compared to the expected bremsstrahlung from final state hadrons. The observed linear increase of the soft photon production rate with the jet total hadron multiplicity and its strong dependence on the jet neutral multiplicity suggest that the rate is proportional to the number of quark pairs produced in the fragmentation process, with the neutral pairs being more effectively radiating than the charged ones. © 2010 The Author(s)
Searches for invisibly decaying Higgs bosons with the DELPHI detector at LEP
No full textGeneral rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 29 Jun 2019 Digital Object Identifier (DOI) 10.1140/epjc/s2003-01469-8 Eur. Phys. J. C 32, 475-492 (2004) Abstract. Searches for HZ production with the Higgs boson decaying into an invisible final state were performed using the data collected by the DELPHI experiment at centre-of-mass energies between 188 GeV and 209 GeV. Both hadronic and leptonic final states of the Z boson were analysed. In addition to the search for a heavy Higgs boson, a dedicated search for a light Higgs boson down to 40 GeV/c 2 was performed. No signal was found. Assuming the Standard Model HZ production cross-section, the mass limit for invisibly decaying Higgs bosons is 112.1 GeV/c 2 at 95% confidence level. An interpretation in the Minimal Supersymmetric extension of the Standard Model (MSSM) and in a Majoron model is also given
Kaon interference in the hadronic decays of the Z
No full textLink to publication Citation for published version (APA): Abreu, P., Agasi, E. E., Boudinov, E., Hao, W., Holthuizen, D. J., Kluit, P. M., ... van Eldik, J. E. (1996). Kaon interference in the hadronic decays of the Z. Physics Letters B, 379, 330. https://doi.org/10.1016/0370-2693(96)00572-2 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. EB ELSEWJER PHYSICS LETTERS B Physics Letters B 379 (1996) [330][331][332][333][334][335][336][337][338][339][340] Kaon interference in the hadronic decays of the Z" Abstract The first measurement of like-sign charged kaon correlations in hadronic decays of the p is presented, based on data collected by the DELPHI detector. The charged kaons are identified by means of ring imaging Cherenkov detectors. A significant enhancement at small values of the four:momentum difference is observed in the ratio of like-sign to unlikesign KK pairs and in the ratio of like-sign pairs to a simulated reference sample. An update of the measurement of KiK:!, interference is also presented. An enhancement is found in the production of pairs of Ki of similar momenta, as compared with a simulated reference sample. The measured Bose-Einstein correlation parameters A and r are similar for charged and neutral kaon pairs. The value of the Bose-Einstein correlation strength A is consistent with unity. ' On leave of absence from IHEP Serpukhov
