SwePub
Sök i SwePub databas

  Extended search

Träfflista för sökning "WFRF:(Rudenko V. N.) "

Search: WFRF:(Rudenko V. N.)

  • Result 1-25 of 52
Sort/group result
   
EnumerationReferenceCoverFind
1.
  • 2017
  • swepub:Mat__t
  •  
2.
  •  
3.
  •  
4.
  •  
5.
  •  
6.
  •  
7.
  •  
8.
  •  
9.
  •  
10.
  •  
11.
  •  
12.
  •  
13.
  • Litvinov, Dmitry, et al. (author)
  • Probing the gravitational redshift with an Earth-orbiting satellite
  • 2018
  • In: Physics Letters, Section A: General, Atomic and Solid State Physics. - : Elsevier BV. - 0375-9601. ; 382:33, s. 2192-2198
  • Journal article (peer-reviewed)abstract
    • We present an approach to testing the gravitational redshift effect using the RadioAstron satellite. The experiment is based on a modification of the Gravity Probe A scheme of nonrelativistic Doppler compensation and benefits from the highly eccentric orbit and ultra-stable atomic hydrogen maser frequency standard of the RadioAstron satellite. Using the presented techniques we expect to reach an accuracy of the gravitational redshift test of order 10−5, a magnitude better than that of Gravity Probe A. Data processing is ongoing, our preliminary results agree with the validity of the Einstein Equivalence Principle.
  •  
14.
  • Bagriy, I.D., et al. (author)
  • H2 - Ecological source of decarbonization - The path to energy independence of Ukraine
  • 2023
  • Book (other academic/artistic)abstract
    • The research studied the pressing problem of the fuel and energy strategy of the XXI century. For the first time, there was shown the diversity of the authors' approach to theoretical and applied problems of hydrogen energy. General issues of fundamental and applied aspects of hydrogen origin were covered. The study provides the results of scientific developments on hydrogen mapping performed within the framework of scientific and practical exploratory and geo-ecological research on more than 200 hydrocarbon objects both on land (including mining fields) and in marine water areas. Prognostic and search system criteria were substantiated, with hydrogen being used for the first time as a component of the complex of methodical solutions in the search practice. The research showed the importance of solving the problem of geo-ecological processes and accidents in mine workings and wells, connected to numerous disasters. According to numerous studies of mine massives, a set of preventive measures and criteria that prevent explosive processes was provided.The presence of a unique complex of natural components of hydrogen technology, solar and wind energy resources and fresh waters of the Danube lakes and the Danube was stated.The study emphasises the decisive role of Ukraine in the competition for primacy in scientific developments. For the first time in world practice, the implementation of global projects for the extraction and production of green and white hydrogen was substantiated.The technology was tested on numerous hydrocarbon deposits, water resources and mine workings and therefore has all the prospects for the effective application in the search and extraction of hydrogen. This monograph can be useful and informative for specialists in the fields of oil and gas geology, general and regional geology, hydrology, environmental protection, as well as for the students and postgraduate students of fuel and energy, oil and gas geological and hydrological areas, as well as for domestic and foreign investors.
  •  
15.
  • Bagriy, I.D., et al. (author)
  • H2 - ENVIRONMENTAL AND ENERGY CHALLENGESOF THE XXI CENTURY. GLOBAL PROJECTSWAYS OF IMPLEMENTATION
  • 2023
  • Book (peer-reviewed)abstract
    • The research studied the pressing problem of the fuel and energy strategy of the XXI century. For the first time, there was shown the diversity of the authors' approach to theoretical and applied problems of hydrogen energy. General issues of fundamental and applied aspects of hydrogen origin were covered. The study provides the results of scientific developments on hydrogen mapping performed within the framework of scientific and practical exploratory and geo-ecological research on more than 200 hydrocarbon objects both on land (including mining fields) and in marine water areas. Prognostic and search system criteria were substantiated, with hydrogen being used for the first time as a component of the complex of methodical solutions in the search practice. The research showed the importance of solving the problem of geo-ecological processes and accidents in mine workings and wells, connected to numerous disasters. According to numerous studies of mine massives, a set of preventive measures and criteria that prevent explosive processes was provided. The presence of a unique complex of natural components of hydrogen technology, solar and wind energy resources and fresh waters of the Danube lakes and the Danube was stated. The study emphasises the decisive role of Ukraine in the competition for primacy in scientific developments. For the first time in world practice, the implementation of global projects for the extraction and production of green and white hydrogen was substantiated. The technology was tested on numerous hydrocarbon deposits, water resources and mine workings and therefore has all the prospects for the effective application in the search and extraction of hydrogen. This monograph can be useful and informative for specialists in the fields of oil and gas geology, general and regional geology, hydrology, environmental protection, as well as for the students and postgraduate students of fuel and energy, oil and gas geological and hydrological areas, as well as for domestic and foreign investors. 
  •  
16.
  • Litvinov, D. A., et al. (author)
  • RadioAstron gravitational redshift experiment: Status update
  • 2018
  • In: 14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Proceedings. - : WORLD SCIENTIFIC. - 9789813226593 ; , s. 3569-3575
  • Conference paper (peer-reviewed)abstract
    • A test of a cornerstone of general relativity, the gravitational redshift effect, is currently being conducted with the RadioAstron spacecraft, which is on a highly eccentric orbit around Earth. Using ground radio telescopes to record the spacecraft signal, synchronized to its ultra-stable on-board H-maser, we can probe the varying flow of time on board with unprecedented accuracy. The observations performed so far, currently being analyzed, have already allowed us to measure the effect with a relative accuracy of 4 × 10−4. We expect to reach 2.5 × 10−5 with additional observations in 2016, an improvement of almost a magnitude over the 40-year old result of the GP-A mission.
  •  
17.
  • Pedersoli, E., et al. (author)
  • Mesoscale morphology of airborne core-shell nanoparticle clusters : x-ray laser coherent diffraction imaging
  • 2013
  • In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16 SI, s. 164033-
  • Journal article (peer-reviewed)abstract
    • Unraveling the complex morphology of functional materials like core-shell nanoparticles and its evolution in different environments is still a challenge. Only recently has the single-particle coherent diffraction imaging (CDI), enabled by the ultrabright femtosecond free-electron laser pulses, provided breakthroughs in understanding mesoscopic morphology of nanoparticulate matter. Here, we report the first CDI results for Co@SiO2 core-shell nanoparticles randomly clustered in large airborne aggregates, obtained using the x-ray free-electron laser at the Linac Coherent Light Source. Our experimental results compare favourably with simulated diffraction patterns for clustered Co@SiO2 nanoparticles with similar to 10 nm core diameter and similar to 30 nm shell outer diameter, which confirms the ability to resolve the mesoscale morphology of complex metastable structures. The findings in this first morphological study of core-shell nanomaterials are a solid base for future time-resolved studies of dynamic phenomena in complex nanoparticulate matter using x-ray lasers.
  •  
18.
  • Duane Loh, N., et al. (author)
  • Profiling structured beams using injected aerosols
  • 2012
  • In: Proceedings of SPIE. - : SPIE. - 9780819492210 ; , s. 850403-
  • Conference paper (peer-reviewed)abstract
    • Profiling structured beams produced by X-ray free-electron lasers (FELs) is crucial to both maximizing signal intensity for weakly scattering targets and interpreting their scattering patterns. Earlier ablative imprint studies describe how to infer the X-ray beam profile from the damage that an attenuated beam inflicts on a substrate. However, the beams in-situ profile is not directly accessible with imprint studies because the damage profile could be different from the actual beam profile. On the other hand, although a Shack-Hartmann sensor is capable of in-situ profiling, its lenses may be quickly damaged at the intense focus of hard X-ray FEL beams. We describe a new approach that probes the in-situ morphology of the intense FEL focus. By studying the translations in diffraction patterns from an ensemble of randomly injected sub-micron latex spheres, we were able to determine the non-Gaussian nature of the intense FEL beam at the Linac Coherent Light Source (SLAC National Laboratory) near the FEL focus. We discuss an experimental application of such a beam-profiling technique, and the limitations we need to overcome before it can be widely applied.
  •  
19.
  • Loh, N. D., et al. (author)
  • Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight
  • 2012
  • In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 486:7404, s. 513-517
  • Journal article (peer-reviewed)abstract
    • The morphology of micrometre-size particulate matter is of critical importance in fields ranging from toxicology(1) to climate science(2), yet these properties are surprisingly difficult to measure in the particles' native environment. Electron microscopy requires collection of particles on a substrate(3); visible light scattering provides insufficient resolution(4); and X-ray synchrotron studies have been limited to ensembles of particles(5). Here we demonstrate an in situ method for imaging individual sub-micrometre particles to nanometre resolution in their native environment, using intense, coherent X-ray pulses from the Linac Coherent Light Source(6) free-electron laser. We introduced individual aerosol particles into the pulsed X-ray beam, which is sufficiently intense that diffraction from individual particles can be measured for morphological analysis. At the same time, ion fragments ejected from the beam were analysed using mass spectrometry, to determine the composition of single aerosol particles. Our results show the extent of internal dilation symmetry of individual soot particles subject to non-equilibrium aggregation, and the surprisingly large variability in their fractal dimensions. More broadly, our methods can be extended to resolve both static and dynamic morphology of general ensembles of disordered particles. Such general morphology has implications in topics such as solvent accessibilities in proteins(7), vibrational energy transfer by the hydrodynamic interaction of amino acids(8), and large-scale production of nanoscale structures by flame synthesis(9).
  •  
20.
  • Martin, A. V., et al. (author)
  • Femtosecond dark-field imaging with an X-ray free electron laser
  • 2012
  • In: Optics Express. - 1094-4087. ; 20:12, s. 13501-13512
  • Journal article (peer-reviewed)abstract
    • The emergence of femtosecond diffractive imaging with X-ray lasers has enabled pioneering structural studies of isolated particles, such as viruses, at nanometer length scales. However, the issue of missing low frequency data significantly limits the potential of X-ray lasers to reveal sub-nanometer details of micrometer-sized samples. We have developed a new technique of dark-field coherent diffractive imaging to simultaneously overcome the missing data issue and enable us to harness the unique contrast mechanisms available in dark-field microscopy. Images of airborne particulate matter (soot) up to two microns in length were obtained using single-shot diffraction patterns obtained at the Linac Coherent Light Source, four times the size of objects previously imaged in similar experiments. This technique opens the door to femtosecond diffractive imaging of a wide range of micrometer-sized materials that exhibit irreproducible complexity down to the nanoscale, including airborne particulate matter, small cells, bacteria and gold-labeled biological samples.
  •  
21.
  • Martin, A. V., et al. (author)
  • Noise-robust coherent diffractive imaging with a single diffraction pattern
  • 2012
  • In: Optics Express. - 1094-4087. ; 20:15, s. 16650-16661
  • Journal article (peer-reviewed)abstract
    • The resolution of single-shot coherent diffractive imaging at X-ray free-electron laser facilities is limited by the low signal-to-noise level of diffraction data at high scattering angles. The iterative reconstruction methods, which phase a continuous diffraction pattern to produce an image, must be able to extract information from these weak signals to obtain the best quality images. Here we show how to modify iterative reconstruction methods to improve tolerance to noise. The method is demonstrated with the hybrid input-output method on both simulated data and single-shot diffraction patterns taken at the Linac Coherent Light Source. (C) 2012 Optical Society of America
  •  
22.
  • Jahnke, T., et al. (author)
  • Inner-Shell-Ionization-Induced Femtosecond Structural Dynamics of Water Molecules Imaged at an X-Ray Free-Electron Laser
  • 2021
  • In: Physical Review X. - : American Physical Society. - 2160-3308. ; 11:4
  • Journal article (peer-reviewed)abstract
    • The ultrafast structural dynamics of water following inner-shell ionization is a crucial issue in high-energy radiation chemistry. We have exposed isolated water molecules to a short x-ray pulse from a free-electron laser and detected momenta of all produced ions in coincidence. By combining experimental results and theoretical modeling, we can image dissociation dynamics of individual molecules in unprecedented detail. We reveal significant molecular structural dynamics in H2O2+, such as asymmetric deformation and bond-angle opening, leading to two-body or three-body fragmentation on a timescale of a few femtoseconds. We thus reconstruct several snapshots of structural dynamics at different time intervals, which highlight dynamical patterns that are relevant as initiating steps of subsequent radiation-damage processes.
  •  
23.
  • Barty, A., et al. (author)
  • Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements
  • 2012
  • In: Nature Photonics. - 1749-4885 .- 1749-4893. ; 6:1, s. 35-40
  • Journal article (peer-reviewed)abstract
    • X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis1. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information1, 2, 3, 4. Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage. Instead, the diffracted X-rays are gated by a rapid loss of crystalline periodicity, producing apparent pulse lengths significantly shorter than the duration of the incident pulse. The shortest apparent pulse lengths occur at the highest resolution, and our measurements indicate that current X-ray free-electron laser technology5 should enable structural determination from submicrometre protein crystals with atomic resolution.
  •  
24.
  • Hantke, Max F., et al. (author)
  • High-throughput imaging of heterogeneous cell organelles with an X-ray laser
  • 2014
  • In: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 8:12, s. 943-949
  • Journal article (peer-reviewed)abstract
    • We overcome two of the most daunting challenges in single-particle diffractive imaging: collecting many high-quality diffraction patterns on a small amount of sample and separating components from mixed samples. We demonstrate this on carboxysomes, which are polyhedral cell organelles that vary in size and facilitate up to 40% of Earth's carbon fixation. A new aerosol sample-injector allowed us to record 70,000 low-noise diffraction patterns in 12 min with the Linac Coherent Light Source running at 120 Hz. We separate different structures directly from the diffraction data and show that the size distribution is preserved during sample delivery. We automate phase retrieval and avoid reconstruction artefacts caused by missing modes. We attain the highest-resolution reconstructions on the smallest single biological objects imaged with an X-ray laser to date. These advances lay the foundations for accurate, high-throughput structure determination by flash-diffractive imaging and offer a means to study structure and structural heterogeneity in biology and elsewhere.
  •  
25.
  • Loh, N. Duane, et al. (author)
  • Sensing the wavefront of x-ray free-electron lasers using aerosol spheres
  • 2013
  • In: Optics Express. - 1094-4087. ; 21:10, s. 12385-12394
  • Journal article (peer-reviewed)abstract
    • Characterizing intense, focused x-ray free electron laser (FEL) pulses is crucial for their use in diffractive imaging. We describe how the distribution of average phase tilts and intensities on hard x-ray pulses with peak intensities of 1021 W/m(2) can be retrieved from an ensemble of diffraction patterns produced by 70 nm-radius polystyrene spheres, in a manner that mimics wavefront sensors. Besides showing that an adaptive geometric correction may be necessary for diffraction data from randomly injected sample sources, our paper demonstrates the possibility of collecting statistics on structured pulses using only the diffraction patterns they generate and highlights the imperative to study its impact on single-particle diffractive imaging.
  •  
Skapa referenser, mejla, bekava och länka
  • Result 1-25 of 52

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view