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Sökning: WFRF:(Wiesner K.)

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1.
  • Adrian-Martinez, S., et al. (författare)
  • A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
  • 2013
  • Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :6
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.
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2.
  • Evans, P. A., et al. (författare)
  • Swift Follow-up Observations of Candidate Gravitational-wave Transient Events
  • 2012
  • Ingår i: The Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 203:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors (within less than 10 minutes) and their candidate sky locations were observed by the Swift observatory (within 12 hr). Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them is consistent with background and the other one was a test, part of a "blind injection challenge." With this work we demonstrate the feasibility of rapid follow-ups of GW transients and establish the sensitivity improvement joint electromagnetic and GW observations could bring. This is a first step toward an electromagnetic follow-up program in the regime of routine detections with the advanced GW instruments expected within this decade. In that regime, multi-wavelength observations will play a significant role in completing the astrophysical identification of GW sources. We present the methods and results from this first combined analysis and discuss its implications in terms of sensitivity for the present and future instruments.
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3.
  • Aasi, J., et al. (författare)
  • Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data
  • 2013
  • Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 87:4
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper presents results of an all-sky search for periodic gravitational waves in the frequency range [50, 1190] Hz and with frequency derivative range of similar to[-20, 1.1] x 10(-10) Hz s(-1) for the fifth LIGO science run (S5). The search uses a noncoherent Hough-transform method to combine the information from coherent searches on time scales of about one day. Because these searches are very computationally intensive, they have been carried out with the Einstein@Home volunteer distributed computing project. Postprocessing identifies eight candidate signals; deeper follow-up studies rule them out. Hence, since no gravitational wave signals have been found, we report upper limits on the intrinsic gravitational wave strain amplitude h(0). For example, in the 0.5 Hz-wide band at 152.5 Hz, we can exclude the presence of signals with h(0) greater than 7.6 x 10(-25) at a 90% confidence level. This search is about a factor 3 more sensitive than the previous Einstein@Home search of early S5 LIGO data.
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4.
  • Aasi, J., et al. (författare)
  • Parameter estimation for compact binary coalescence signals with the first generation gravitational-wave detector network
  • 2013
  • Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 88:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and in the calibration of the detectors. Here we report such measurements on a selection of simulated signals added either in hardware or software to the data collected by the two LIGO instruments and the Virgo detector during their most recent joint science run, including a "blind injection'' where the signal was not initially revealed to the collaboration. We exemplify the ability to extract information about the source physics on signals that cover the neutron-star and black-hole binary parameter space over the component mass range 1M(circle dot)-25M(circle dot) and the full range of spin parameters. The cases reported in this study provide a snapshot of the status of parameter estimation in preparation for the operation of advanced detectors.
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5.
  • Aasi, J., et al. (författare)
  • Search for gravitational waves from binary black hole inspiral, merger, and ringdown in LIGO-Virgo data from 2009-2010
  • 2013
  • Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 87:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We report a search for gravitational waves from the inspiral, merger and ringdown of binary black holes (BBH) with total mass between 25 and 100 solar masses, in data taken at the LIGO and Virgo observatories between July 7, 2009 and October 20, 2010. The maximum sensitive distance of the detectors over this period for a (20, 20)M-circle dot coalescence was 300 Mpc. No gravitational wave signals were found. We thus report upper limits on the astrophysical coalescence rates of BBH as a function of the component masses for nonspinning components, and also evaluate the dependence of the search sensitivity on component spins aligned with the orbital angular momentum. We find an upper limit at 90% confidence on the coalescence rate of BBH with nonspinning components of mass between 19 and 28M(circle dot) of 3:3 x 10(-7) mergers Mpc(-3) yr(-1).
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6.
  • Aasi, J., et al. (författare)
  • The characterization of Virgo data and its impact on gravitational-wave searches
  • 2012
  • Ingår i: Classical and Quantum Gravity. - : IOP Publishing. - 1361-6382 .- 0264-9381. ; 29:15
  • Tidskriftsartikel (refereegranskat)abstract
    • Between 2007 and 2010 Virgo collected data in coincidence with the LIGO and GEO gravitational-wave (GW) detectors. These data have been searched for GWs emitted by cataclysmic phenomena in the universe, by non-axisymmetric rotating neutron stars or from a stochastic background in the frequency band of the detectors. The sensitivity of GW searches is limited by noise produced by the detector or its environment. It is therefore crucial to characterize the various noise sources in a GW detector. This paper reviews the Virgo detector noise sources, noise propagation, and conversion mechanisms which were identified in the three first Virgo observing runs. In many cases, these investigations allowed us to mitigate noise sources in the detector, or to selectively flag noise events and discard them from the data. We present examples from the joint LIGO-GEO-Virgo GW searches to show how well noise transients and narrow spectral lines have been identified and excluded from the Virgo data. We also discuss how detector characterization can improve the astrophysical reach of GW searches.
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7.
  • Hudson, Thomas J., et al. (författare)
  • International network of cancer genome projects
  • 2010
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 464:7291, s. 993-998
  • Tidskriftsartikel (refereegranskat)abstract
    • The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.
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8.
  • Kredo, T., et al. (författare)
  • Interaction between Artemether-Lumefantrine and Nevirapine-Based Antiretroviral Therapy in HIV-1-Infected Patients
  • 2011
  • Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 55:12, s. 5616-5623
  • Tidskriftsartikel (refereegranskat)abstract
    • Artemether-lumefantrine and nevirapine-based antiretroviral therapy (ART) are the most commonly recommended first-line treatments for malaria and HIV, respectively, in Africa. Artemether, lumefantrine, and nevirapine are metabolized by the cytochrome P450 3A4 enzyme system, which nevirapine induces, creating potential for important drug interactions. In a parallel-design pharmacokinetic study, concentration-time profiles were obtained in two groups of HIV-infected patients: ART-naive patients and those stable on nevirapine-based therapy. Both groups received the recommended artemether-lumefantrine dose. Patients were admitted for intense pharmacokinetic sampling (0 to 72 h) with outpatient sampling until 21 days. Concentrations of lumefantrine, artemether, dihydroartemisinin, and nevirapine were determined by validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The primary outcome was observed day 7 lumefantrine concentrations, as these are associated with therapeutic response in malaria. We enrolled 36 patients (32 females). Median (range) day 7 lumefantrine concentrations were 622 ng/ml (185 to 2,040 ng/ml) and 336 ng/ml (29 to 934 ng/ml) in the nevirapine and ART-naive groups, respectively (P = 0.0002). The median artemether area under the plasma concentration-time curve from 0 to 8 h [AUC((0-8 h))] (P < 0.0001) and dihydroartemisinin AUC((60-68 h)) (P = 0.01) were lower in the nevirapine group. Combined artemether and dihydroartemisinin exposure decreased over time only in the nevirapine group (geometric mean ratio [GMR], 0.76 [95% confidence interval {CI}, 0.65 to 0.90]; P < 0.0001) and increased with the weight-adjusted artemether dose (GMR, 2.12 [95% CI, 1.31 to 3.45]; P = 0.002). Adverse events were similar between groups, with no difference in electrocardiographic Fridericia corrected QT and P-R intervals at the expected time of maximum lumefantrine concentration (T(max)). Nevirapine-based ART decreased artemether and dihydroartemisinin AUCs but unexpectedly increased lumefantrine exposure. The mechanism of the lumefantrine interaction remains to be elucidated. Studies investigating the interaction of nevirapine and artemether-lumefantrine in HIV-infected patients with malaria are urgently needed.
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9.
  • Burmeister, F., et al. (författare)
  • A study of the inner-valence ionization region in HCl and DCl
  • 2004
  • Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 37:6, s. 1173-1183
  • Tidskriftsartikel (refereegranskat)abstract
    • An in-depth photoionization study of the inner-valence electrons in HCl and DCl has been performed using synchrotron radiation. A series of photoelectron spectra of HCl were obtained at a resolution of 23 meV over the binding energy range 25-30.5 eV at various excitation energies and at two different electron collection angles relative to the plane of polarization of the undulator radiation. In addition, photoelectron spectra of DCl were recorded at two different excitation energies. These spectra were compared directly with the threshold photoelectron spectra of HCl and DCl that were recorded previously under similar resolution conditions (similar to30 meV). This comparative study reveals new information on the nature of the numerous band systems observed in this binding energy region. In addition, we present the experimental confirmation of the theoretical prediction given by Andersson et al (2001 Phys. Rev. A 65 012705) that a vibrational progression showing interference structure would appear in the main inner-valence ionization band in the photoelectron spectrum of DCl at a resolution of 10 meV.
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10.
  • Giertz, A., et al. (författare)
  • Vibrationally resolved photoelectron spectra of the carbon 1s and nitrogen 1s shells in hydrogen cyanide
  • 2002
  • Ingår i: Chemical Physics. - 0301-0104. ; 277:1, s. 83-90
  • Tidskriftsartikel (refereegranskat)abstract
    • Vibrational structures of the C1s and N1s photoelectron spectra of gas-phase HCN have been investigated using monochromated third-generation synchrotron radiation. Both spectra exhibit resolved fine structure associated with several vibrationally excited states. In the C1s spectrum a single vibrational progression is observed, while the N1s spectrum is more complex. High-level ab initio calculations were performed to simulate the spectra and the agreement with the experimental results is good. Based on the calculations, the C1s ionisation is found to induce vibrations solely in the C≡N stretching mode with an energy of 280 meV, while the N1s ionisation generates vibrations also in the C-H stretching mode with an energy of about 387 meV, as well as combinations of these two modes.
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13.
  • Abolfathi, Bela, et al. (författare)
  • The LSST DESC DC2 Simulated Sky Survey
  • 2021
  • Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 253:31
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe the simulated sky survey underlying the second data challenge (DC2) carried out in preparation for analysis of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) by the LSST Dark Energy Science Collaboration (LSST DESC). Significant connections across multiple science domains will be a hallmark of LSST; the DC2 program represents a unique modeling effort that stresses this interconnectivity in a way that has not been attempted before. This effort encompasses a full end-to-end approach: starting from a large N-body simulation, through setting up LSST-like observations including realistic cadences, through image simulations, and finally processing with Rubin's LSST Science Pipelines. This last step ensures that we generate data products resembling those to be delivered by the Rubin Observatory as closely as is currently possible. The simulated DC2 sky survey covers six optical bands in a wide-fast-deep area of approximately 300 deg2, as well as a deep drilling field of approximately 1 deg2. We simulate 5 yr of the planned 10 yr survey. The DC2 sky survey has multiple purposes. First, the LSST DESC working groups can use the data set to develop a range of DESC analysis pipelines to prepare for the advent of actual data. Second, it serves as a realistic test bed for the image processing software under development for LSST by the Rubin Observatory. In particular, simulated data provide a controlled way to investigate certain image-level systematic effects. Finally, the DC2 sky survey enables the exploration of new scientific ideas in both static and time domain cosmology.
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14.
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15.
  • Burmeister, F, et al. (författare)
  • Nonadiabatic effects in photoelectron spectra of HCl and DCl. I. Experiment
  • 2002
  • Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 65:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The HCl inner-valence photoelectron band at 26 eV binding energy has been recorded at high resolution. Discrete peaks arising from at least two separate vibrational progressions are superimposed on the broad continuum. Fano profiles are visible in one of the progressions. This indicates interference between superimposed electronic states, where weak avoided crossing allows two adiabatic states to couple. In the isotopic DCl molecular spectrum, the discrete lines are less pronounced, due to slower dissociation and therefore less coupling between the continuum and the bound state.
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16.
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17.
  • De Brito, A. N., et al. (författare)
  • Evidence against atomiclike resonant auger decay in N2 doubly excited core states by high-resolution experiments
  • 2001
  • Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947. ; 64:5, s. 547021-547024
  • Tidskriftsartikel (refereegranskat)abstract
    • The resonant Auger decay spectra associated with doubly excited core-hole states near the N 1s threshold in the nitrogen molecule was measured. Electron-yield spectrum was obtained by setting a kinetic-energy window at 384 eV and scanning across the threshold region. At ground 410, 414, and 416 eV, photon energy, three dominant structures were observed. The increased signal-to-background ratio, intensity and resolution at third generation facilities were found to cast a different light on the dynamics of core photoionization in molecules.
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18.
  • Feifel, R., et al. (författare)
  • "Hidden" vibrations in CO : Reinvestigation of resonant Auger decay for the C 1s → π* excitation
  • 2002
  • Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947. ; 65:5 A, s. 527011-527018
  • Tidskriftsartikel (refereegranskat)abstract
    • The higher vibrational levels of the C 1s→π* excitation in carbon monooxide (CO) were investigated by using resonant Auger electron spectroscopy. The absorption profile of the CO was recorded in the partial electron yield mode. The results showed that the vibrational states were not seen in a total yield absorption spectrum whereas they were shown to be discernable in a partial electron yield spectrum.
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19.
  • Fink, RF, et al. (författare)
  • Spin-orbit selectivity observed for the HCl+ ((X)over-tilde (II)-I-2) state using resonant photoemission
  • 2002
  • Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 65:3
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the experimental observation of a strongly selective population of the spin-orbit components in the HCl+ (X) over tilde (2)Pi(Omega) states after excitation into the dissociative 2p(-1)6sigma* core excited state. A progression of highly excited vibrational states with either the Omega=3/2 or Omega=1/2 component of the final state is populated, respectively, when the excitation is tuned in the 2p(3/2)(-1)6sigma*or2p(1/2)(-1)6 sigma* part of the resonance. This effect is explained theoretically to be due to the orientational selectivity of the excitation process and the preference of the L-2,L-3 VV Auger process to produce valence holes with the same orientation as the core holes.
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22.
  • Hauge, Jannicke B., et al. (författare)
  • Applying gamification for developing formal knowledge models : Challenges and requirements
  • 2016
  • Ingår i: IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS 2016. - Cham : Springer-Verlag New York. - 9783319511320 ; , s. 713-720
  • Konferensbidrag (refereegranskat)abstract
    • A main challenge in developing formal knowledge models is to efficiently elicit knowledge from various resources and form a coherent body of knowledge that can be validated and extended by user communities. The higher the complexity of a system, the more challenging it is to establish these models, specifically if there are several stakeholders involved, with various level of knowledge and needs. The usage of participatory design approaches in combination with Serious Games (SG) could ensure that all stakeholders are active, as well as that each perspective can be considered. So far manufacturing concepts have not reached their full potential due to the fact that gamification efforts are costly, time consuming to develop, and require the constant involvement of developers even for small changes. The authors discuss the use of a gamification tool to support knowledge processes, respectively knowledge experiencing, conceptualizing, analyzing and applying in engineering environments. To support this approach, especially in terms of costs, the paper presents an approach that makes customization accessible for non-SG professionals.
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24.
  • Hjelte, I, et al. (författare)
  • Evidence for ultra-fast dissociation of molecular water from resonant Auger spectroscopy
  • 2001
  • Ingår i: CHEMICAL PHYSICS LETTERS. - : ELSEVIER SCIENCE BV. - 0009-2614. ; 334:1-3, s. 151-158
  • Tidskriftsartikel (refereegranskat)abstract
    • We present direct evidence for ultra-fast dissociation of molecular water in connection photo-excitation of the Ols --> 4a(1) resonance. The core-excited H2O molecules are shown to dissociate into core-excited O*H and neutral H on a time scale comparable
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25.
  • Hjelte, I., et al. (författare)
  • Evidence for ultra-fast dissociation of molecular water from resonant Auger spectroscopy
  • 2001
  • Ingår i: Chemical Physics Letters. - 0009-2614. ; 334:1-3, s. 151-158
  • Tidskriftsartikel (refereegranskat)abstract
    • We present direct evidence for ultra-fast dissociation of molecular water in connection photo-excitation of the O1s→4a1 resonance. The core-excited H2O molecules are shown to dissociate into core-excited O*H and neutral H on a time scale comparable to the core hole lifetime, i.e. a few femtoseconds. This conclusion is based on a resonant Auger study, qualitative arguments and ab initio calculations. 'Hot bands' connected to Auger transitions from vibrationally excited OH fragments are identified, and these exhibit a dynamical behavior which qualitatively follows the change in excess energy.
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26.
  • Hjelte, I, et al. (författare)
  • Evidence of ultra-fast dissociation in ammonia observed by resonant Auger electron spectroscopy
  • 2003
  • Ingår i: Chemical Physics Letters. - 0009-2614. ; 370:5-6, s. 781-788
  • Tidskriftsartikel (refereegranskat)abstract
    • We present evidence for ultra-fast dissociation of molecular ammonia when photo-excited to the Nls --> 4a(1) core-hole state. This finding is based on resonant Auger spectroscopical results as well as qualitative arguments concerning the photon energy dependence of the Auger structures. Calculations of the excited state potential based on the Z + l approximation were performed. Both the calculations and the measurements indicate that the most likely fragmentation pathway for the core excited ammonia molecules leads to NH2* and H fragments. (C) 2003 Elsevier Science B.V. All rights reserved.
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28.
  • Mocellin, A, et al. (författare)
  • Experimental study of photoionization of ozone in the 12 to 21 eV region
  • 2001
  • Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 115:11, s. 5041-5046 Language: English
  • Tidskriftsartikel (refereegranskat)abstract
    • The total and partial ion yield of ozone using time-of-flight is presented. The measurements were done using multicoincidence between a photoelectron and a photoion (PEPICO). Comparison with the photoelectron spectrum and previous measurements using other
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29.
  • Myrseth Oltedal, Velaug, et al. (författare)
  • Vibrational structure and vibronic coupling in the carbon 1s photoelectron spectra of benzene and deuterobenzene
  • 2002
  • Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084. ; 4:24, s. 5937-5943
  • Tidskriftsartikel (refereegranskat)abstract
    • Vibrationally resolved C1s photoelectron spectra of benzene and d(6)-benzene have been recorded using monochromated synchrotron radiation at photon energies of 330 eV. The spectrum of normal benzene displays considerable vibrational structure. Particularly noteworthy is the strong excitation of a combined CCH-bending and CC-stretching mode which splits the main peak into two well-defined maxima. In d(6)-benzene, the vibrational energy levels are less well separated and the vibrational structure is reduced to strong asymmetry of the main peak and a broad tail extending toward higher ionization energy. The recorded spectra are analyzed using first-principle and curve-fitting procedures. A theoretical model that allows for incomplete localization of the core hole, results in very good fits to the experimental spectra of both benzene and d(6)-benzene.
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30.
  • Pivarcsi, Andor, et al. (författare)
  • Tumor immune escape by the loss of homeostatic chemokine expression.
  • 2007
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 104:48, s. 19055-60
  • Tidskriftsartikel (refereegranskat)abstract
    • The novel keratinocyte-specific chemokine CCL27 plays a critical role in the organization of skin-associated immune responses by regulating T cell homing under homeostatic and inflammatory conditions. Here we demonstrate that human keratinocyte-derived skin tumors may evade T cell-mediated antitumor immune responses by down-regulating the expression of CCL27 through the activation of epidermal growth factor receptor (EGFR)-Ras-MAPK-signaling pathways. Compared with healthy skin, CCL27 mRNA and protein expression was progressively lost in transformed keratinocytes of actinic keratoses and basal and squamous cell carcinomas. In vivo, precancerous skin lesions as well as cutaneous carcinomas showed significantly elevated levels of phosphorylated ERK compared with normal skin, suggesting the activation of EGFR-Ras signaling pathways in keratinocyte-derived malignancies. In vitro, exogenous stimulation of the EGFR-Ras signaling pathway through EGF or transfection of the dominant-active form of the Ras oncogene (H-RasV12) suppressed whereas an EGFR tyrosine kinase inhibitor increased CCL27 mRNA and protein production in keratinocytes. In mice, neutralization of CCL27 led to decreased leukocyte recruitment to cutaneous tumor sites and significantly enhanced primary tumor growth. Collectively, our data identify a mechanism of skin tumors to evade host antitumor immune responses.
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31.
  • Rosenqvist, L, et al. (författare)
  • Femtosecond dissociation of ozone studied by the Auger Doppler effect
  • 2001
  • Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 115:8, s. 3614-3620 Language: English
  • Tidskriftsartikel (refereegranskat)abstract
    • A Doppler-type shift in the kinetic energy of atomic Auger electrons emitted after fast dissociation of O-3 molecules is observed. The resonant Auger spectrum from the decay of repulsive core-excited states reflects both the early molecular ozone decay an
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32.
  • Rosenqvist, L., et al. (författare)
  • Femtosecond dissociation of ozone studied by the Auger Doppler effect
  • 2001
  • Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 115:8, s. 3614-3620
  • Tidskriftsartikel (refereegranskat)abstract
    • The peaks arising from the decay of the excited oxygen atom were studied. Fast dissociation of core-excited ozone was confirmed by the presence of Auger emission from atomic oxygen in the decay spectrum from the ozone OT 1s-σ*(7a1) state. No such emission was observed after excitation of the corresponding state on the central oxygen atom. An angle-dependent energy shift of the atomic lines was observed. Analysis of the energy shift revealed that the kinetic energy released in the dissociation process is approximately 3.3 ± 0.3eV. An energy release of 8.45 was found by application of a Born-Haber cycle.
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33.
  • Schaal, J., et al. (författare)
  • Coumarin-based octopamine phototriggers and their effects on an insect octopamine receptor
  • 2012
  • Ingår i: ChemBioChem. - : Wiley. - 1439-4227 .- 1439-7633. ; 13:10, s. 1458-1464
  • Tidskriftsartikel (refereegranskat)abstract
    • We have developed and characterized efficient caged compounds of the neurotransmitter octopamine. For derivatization, we introduced [6-bromo-8-(diethylaminomethyl)-7-hydroxycoumarin-4-yl]methoxycarbonyl (DBHCMOC) and {6-bromo-7-hydroxy-8-[(piperazin-1-yl)methyl]coumarin-4-yl}methoxycarbonyl (PBHCMOC) moieties as novel photo-removable protecting groups. The caged compounds were functionally inactive when applied to heterologously expressed octopamine receptors (AmOctα1R). Upon irradiation with UV–visible or IR light, bioactive octopamine was released and evoked Ca2+ signals in AmOctα1R-expressing cells. The pronounced water solubility of compounds 2–4 in particular holds great promise for these substances as excellent phototriggers of this important neurotransmitter.
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34.
  • Wang, H., et al. (författare)
  • Filtering core excitation spectra : Vibrationally resolved constant ionic state studies of N 1s → 2π core-excited NO
  • 2001
  • Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 34:22, s. 4417-4426
  • Tidskriftsartikel (refereegranskat)abstract
    • High-resolution electron spectroscopy studies of the NO molecule in the regions of the N 1s → 2π core excitations have been performed. By selecting electrons within certain binding energy ranges, either the Auger electron yield - a good approximation for the x-ray absorption spectrum - or the electrons emitted after decay to a particular ionic final state (constant ionic state (CIS)) were detected. By selecting the X 1Σ+ (2π0) final state, the superposition of several intermediate state can be disentangled by exploiting a selection rule which permits only two of the three dipole-allowed intermediate states to decay to this specific final state. This makes it possible to obtain more detailed information on the potential energy curves of the intermediate states than is available from regular absorption measurements. We have also obtained CIS spectra for individual vibrational sublevels within this state. The role of lifetime vibrational interference on the appearance of these spectra is discussed.
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35.
  • Wang, H, et al. (författare)
  • Is there interference in the resonant Auger electron spectra of N 1s and O 1s -> 2 pi core excited NO?
  • 2003
  • Ingår i: Chemical Physics. - 0301-0104. ; 289:1, s. 31-44
  • Tidskriftsartikel (refereegranskat)abstract
    • High-resolution, angle-resolved resonant Auger electron spectra of the NO molecule in the regions of both N and O 1s --> 2pi core electron excitations are presented. A large number of vibrational final states are resolved due to high energy resolution. Calculations based on lifetime vibrational interference (LVI) theory neglecting interference between different electronic intermediate states and between direct and resonant channels have been performed. A comparison between theoretical and experimental spectra shows that LVI theory describes the major spectroscopic features quite well. The same holds for the evolution of the angular averaged partial cross sections with the change of excitation energy. The angular distribution of particular vibrational final states are, however, not described successfully with LVI calculations at the present level of sophistication. A theoretical analysis supports that one reason for this deviation is electronic state interference. (C) 2002 Elsevier Science B.V. All rights reserved.
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36.
  • Wiesner, K, et al. (författare)
  • Core excitation in O-3 localized to one of two symmetry-equivalent chemical bonds: Molecular alignment through vibronic coupling
  • 2005
  • Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 122:15
  • Tidskriftsartikel (refereegranskat)abstract
    • Core excitation from terminal oxygen O-T in O-3 is shown to be an excitation from a localized core orbital to a localized valence orbital. The valence orbital is localized to one of the two equivalent chemical bonds. We experimentally demonstrate this with the Auger-Doppler effect which is observable when O-3 is core excited to the highly dissociative O(T)1S(-)17a(1)(1) state. Auger electrons emitted from the atomic oxygen fragment carry information about the molecular orientation relative to the electromagnetic-field vector at the moment of excitation. The data together with analytical functions for the electron-peak profiles give clear evidence that the preferred molecular orientation for excitation only depends on the orientation of one bond, not on the total molecular orientation. The localization of the valence orbital "7a(1)" is caused by mixing of the valence orbital "5b(2)" through vibronic coupling of antisymmetric stretching mode with b(2) symmetry. To the best of our knowledge, it is the first discussion of the localization of a core excitation of O-3. This result explains the success of the widely used assumption of localized core excitation in adsorbates and large molecules.
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37.
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38.
  • Wiesner, K., et al. (författare)
  • Haematopoietic stem cells : Entropic landscapes of differentiation
  • 2018
  • Ingår i: Interface Focus. - : The Royal Society. - 2042-8898 .- 2042-8901. ; 8:6
  • Tidskriftsartikel (refereegranskat)abstract
    • The metaphor of a potential epigenetic differentiation landscape broadly suggests that during differentiation a stem cell approaches a stable equilibrium state from a higher free energy towards a stable equilibrium state which represents the final cell type. It has been conjectured that there is an analogy to the concept of entropy in statistical mechanics. In this context, in the undifferentiated state, the entropy would be large since fewer constraints exist on the gene expression programmes of the cell. As differentiation progresses, gene expression programmes become more and more constrained and thus the entropy would be expected to decrease. In order to assess these predictions, we compute the Shannon entropy for time-resolved single-cell gene expression data in two different experimental set-ups of haematopoietic differentiation. We find that the behaviour of this entropy measure is in contrast to these predictions. In particular, we find that the Shannon entropy is not a decreasing function of developmental pseudo-time but instead it increases towards the time point of commitment before decreasing again. This behaviour is consistent with an increase in gene expression disorder observed in populations sampled at the time point of commitment. Single cells in these populations exhibit different combinations of regulator activity that suggest the presence of multiple configurations of a potential differentiation network as a result of multiple entry points into the committed state.
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39.
  • Wiesner, K, et al. (författare)
  • The dynamic Auger-Doppler effect in HF and DF: control of fragment velocities in femtosecond dissociation through photon energy detuning
  • 2002
  • Ingår i: Chemical Physics Letters. - 0009-2614. ; 354:5-6, s. 382-388
  • Tidskriftsartikel (refereegranskat)abstract
    • The Auger-Doppler effect in the experimental spectra of HF and DF is presented. and the dynamics of ultra-fast dissociation in the core-excited state are discussed. The Doppler splitting of the atomic Auger peak is calculated and simulated using a classical model and a very good agreement is found between experiment and simulation. It is shown that the difference in photon energy relative to the resonance is transferred completely into the kinetic energy release (KER). This is expected to be a general phenomenon, but is clearly illuminated in the HF/DF case, Thus the fragment velocity can be controlled through photon energy detuning.
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40.
  • Wiesner, K, et al. (författare)
  • Valence photoionization and resonant core excitation of ozone - experimental and theoretical study of the (C)over-tilde-state of O-3(+)
  • 2003
  • Ingår i: Chemical Physics Letters. - 0009-2614. ; 375:1-2, s. 76-83
  • Tidskriftsartikel (refereegranskat)abstract
    • Resonant Auger electron spectra of core excited O-3 (O(F)1s(-1) 2b(1)(1)) are presented for the first time. The photoionization valence spectrum with sample purity and resolution superior to those published is presented. The first direct experimental evidence for the (C) over tilde (2) B-1 state of O-3(+) is found. Ab initio calculations of the resonant Auger electron (RAE) spectrum have been performed supporting the assignment of the (C) over tilde -state. (C) 2003 Elsevier Science B.V. All rights reserved.
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41.
  • Wiesner, S., et al. (författare)
  • Effects of environmental dynamicity on requirements engineering for complex systems
  • 2017
  • Ingår i: IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS 2017. - Cham : Springer. - 9783319669229 ; , s. 255-262
  • Konferensbidrag (refereegranskat)abstract
    • With customers demanding more and more holistic answers to their problems, solution providers respond with complex systems, integrating product, service and ICT elements into their offer. These solutions need to be aligned to a high number of requirements, coming not only from the individual customer but also from an environment of network partners, technology providers and other stakeholders. Especially for Product-Service Systems, where the solution provider takes responsibility in the operational phase, this environment is dynamic over the system life cycle. Stakeholders may enter or leave, as well as changing needs and technological capabilities. This makes the requirements towards the solution volatile, demanding a suitable Requirements Engineering approach. In this paper, it is discussed how environmental dynamicity can be monitored for its effect on requirements, with a special focus on organizational issues. Through a literature review and industrial case studies it is analysed, how it can be ensured that environmental changes can be taken into account in Requirements Engineering, leading to an optimal system configuration to address the customer problem.
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42.
  • Wiesner, S., et al. (författare)
  • Supporting the requirements elicitation process for cyber-physical product-service systems through a gamified approach
  • 2016
  • Ingår i: IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS 2016. - Cham : Springer New York LLC. - 9783319511320 ; , s. 687-694
  • Konferensbidrag (refereegranskat)abstract
    • Solutions are offered more and more in the form of Product- Service Systems (PSS), which combine tangible and intangible components into a comprehensive package for the customer. The rise of Internet of Things technology enables new ways of integrating products and services. So-called Cyber-Physical Systems (CPS) include the necessary sensors, actuators and software to provide reconfigurable functionalities for changing demands. However, engineering complexity is increased by the evolutionary aspect, as well as the increased number of stakeholders and system components involved over the whole life cycle. Understanding the underlying requirements is fundamental to establish a common perception of the targeted system among the manufacturer, service providers and the other stakeholders. This paper presents a gamified approach to elicit stakeholder requirements for the development of these complex systems. Four industrial users will use the gamified environment for refining their existing requirements. 
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