A collision chamber for the study of high energy ion molecule reactions at high resolution

It is possible to produce metallic materials with submicrometer-grained (SMG) structures by imposing an intense plastic strain under quasi-hydrostatic pressure. Studies using conventional transmission electron microscopy (CTEM) showed that many grain boundaries in the SMG structures appeared diffuse in nature with poorly defined transition zones between individual grains. The implication of the CTEM observations is that the grain boundaries of the SMG structures are in a high energy state, having non-equilibrium character. It is anticipated that high-resolution electron microscopy (HREM) will serve to reveal a precise nature of the grain boundary structure in SMG materials. A recent study on nanocrystalline Ni and Ni3Al showed lattice distortion and dilatations in the vicinity of the grain boundaries. In this study, HREM observations are undertaken to examine the atomic structure of grain boundaries in an SMG Al-based Al-Mg alloy.An Al-3%Mg solid solution alloy was subjected to torsion straining to produce an equiaxed grain structure with an average grain size of ~0.09 μm.

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Ultra high resolution SEM at high voltage images individual fab fragments applied as molecular label to cell surface receptors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015232x ◽

1989 ◽

Vol 47 ◽

pp. 70-71

Author(s):

Klaus-Ruediger Peters

Keyword(s):

High Resolution ◽

High Energy ◽

Metal Coating ◽

Beam Diameter ◽

Surface Receptors ◽

Surface Mobility ◽

Metal Atoms ◽

Shadowing Effect ◽

Imaging Mode ◽

Deposition Techniques

Topographic ultra high resolution can now routinely be established on bulk samples in cold field emission scanning electron microscopy with a second generation of microscopes (FSEM) designed to provide 0.5 nm probe diameters. If such small probes are used for high magnification imaging, topographic contrast is so high that remarkably fine details can be imaged on 2DMSO/osmium-impregnated specimens at ribosome surfaces even without a metal coating. On TCH/osmium-impregnated specimens topographic resolution can be increased further if the SE-I imaging mode is applied. This requires that beam diameter and metal coating thickness be made smaller than the SE range of ~1 nm and background signal contributions be reduced. Subnanometer small probes can be obtained (only) at high accelerating voltages. Subnanometer thin continuous metal films can be produced under the following conditions: self-shadowing effect between metal atoms must be reduced through appropriate deposition techniques and surface mobility of metal atoms must be diminished through high energy sputtering and/or specimen cooling.

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Interaction Between Basal Stacking Faults and Prismatic Inversion Domain Boundaries in GaN

MRS Proceedings ◽

10.1557/proc-639-g3.44 ◽

2000 ◽

Vol 639 ◽

Cited By ~ 1

Author(s):

Philomela Komninou ◽

Joseph Kioseoglou ◽

Eirini Sarigiannidou ◽

George P. Dimitrakopulos ◽

Thomas Kehagias ◽

...

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Stacking Faults ◽

High Resolution Electron Microscopy ◽

High Energy ◽

Low Energy ◽

Inversion Domain ◽

Resolution Electron ◽

Domain Boundaries ◽

Inversion Domain Boundaries

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.

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3-Dimensional Characterization of Polycrystalline Bulk Materials Using High-Energy Synchrotron Radiation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.2353 ◽

2007 ◽

Vol 539-543 ◽

pp. 2353-2358 ◽

Cited By ~ 10

Author(s):

Ulrich Lienert ◽

Jonathan Almer ◽

Bo Jakobsen ◽

Wolfgang Pantleon ◽

Henning Friis Poulsen ◽

...

Keyword(s):

High Resolution ◽

Synchrotron Radiation ◽

High Energy ◽

Mapping Technique ◽

X Ray Diffraction ◽

Bulk Materials ◽

Reciprocal Space Mapping ◽

3 Dimensional ◽

Individual Grains

The implementation of 3-Dimensional X-Ray Diffraction (3DXRD) Microscopy at the Advanced Photon Source is described. The technique enables the non-destructive structural characterization of polycrystalline bulk materials and is therefore suitable for in situ studies during thermo-mechanical processing. High energy synchrotron radiation and area detectors are employed. First, a forward modeling approach for the reconstruction of grain boundaries from high resolution diffraction images is described. Second, a high resolution reciprocal space mapping technique of individual grains is presented.

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Short pulse, high resolution, backlighters for point projection high-energy radiography at the National Ignition Facility

Physics of Plasmas ◽

10.1063/1.4983137 ◽

2017 ◽

Vol 24 (5) ◽

pp. 053104 ◽

Cited By ~ 20

Author(s):

R. Tommasini ◽

C. Bailey ◽

D. K. Bradley ◽

M. Bowers ◽

H. Chen ◽

...

Keyword(s):

High Resolution ◽

Short Pulse ◽

High Energy ◽

National Ignition Facility ◽

Point Projection

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The effects of the big storm events in the first half of 2015 on the radiation belts observed by EPT/PROBA-V

Annales Geophysicae ◽

10.5194/angeo-34-75-2016 ◽

2016 ◽

Vol 34 (1) ◽

pp. 75-84 ◽

Cited By ~ 10

Author(s):

V. Pierrard ◽

G. Lopez Rosson

Keyword(s):

Charged Particle ◽

High Resolution ◽

Geomagnetic Storm ◽

Energetic Particle ◽

High Energy ◽

Radiation Belts ◽

Radiation Environment ◽

Storm Event ◽

Storm Events ◽

Particle Radiation

Abstract. With the energetic particle telescope (EPT) performing with direct electron and proton discrimination on board the ESA satellite PROBA-V, we analyze the high-resolution measurements of the charged particle radiation environment at an altitude of 820 km for the year 2015. On 17 March 2015, a big geomagnetic storm event injected unusual fluxes up to low radial distances in the radiation belts. EPT electron measurements show a deep dropout at L > 4 starting during the main phase of the storm, associated to the penetration of high energy fluxes at L < 2 completely filling the slot region. After 10 days, the formation of a new slot around L = 2.8 for electrons of 500–600 keV separates the outer belt from the belt extending at other longitudes than the South Atlantic Anomaly. Two other major events appeared in January and June 2015, again with injections of electrons in the inner belt, contrary to what was observed in 2013 and 2014. These observations open many perspectives to better understand the source and loss mechanisms, and particularly concerning the formation of three belts.

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P-wave velocity and density structure beneath Mt. Vesuvius: a magma body in the upper edifice?

Annals of Geophysics ◽

10.4401/ag-6443 ◽

2013 ◽

Vol 56 (4) ◽

Author(s):

Paolo Capuano ◽

Guido Russo ◽

Roberto Scarpa

Keyword(s):

High Resolution ◽

Wave Velocity ◽

Gravity Data ◽

High Energy ◽

P Wave ◽

Gravity Inversion ◽

Density Structure ◽

Resolution Image ◽

High Resolution Image ◽

P Wave Velocity

<p>A high-resolution image of the compressional wave velocity and density structure in the shallow edifice of Mount Vesuvius has been derived from simultaneous inversion of travel times and hypocentral parameters of local earthquakes and from gravity inversion. The robustness of the tomography solution has been improved by adding to the earthquake data a set of land based shots, used for constraining the travel time residuals. The results give a high resolution image of the P-wave velocity structure with details down to 300-500 m. The relocated local seismicity appears to extend down to 5 km depth below the central crater, distributed into two clusters, and separated by an anomalously high Vp region positioned at around 1 km depth. A zone with high Vp/Vs ratio in the upper layers is interpreted as produced by the presence of intense fluid circulation alternatively to the interpretation in terms of a small magma chamber inferred by petrologic studies. In this shallower zone the seismicity has the minimum energy, whilst most of the high-energy quakes (up to Magnitude 3.6) occur in the cluster located at greater depth. The seismicity appears to be located along almost vertical cracks, delimited by a high velocity body located along past intrusive body, corresponding to remnants of Mt. Somma. In this framework a gravity data inversion has been performed to study the shallower part of the volcano. Gravity data have been inverted using a method suitable for the application to scattered data in presence of relevant topography based on a discretization of the investigated medium performed by establishing an approximation of the topography by a triangular mesh. The tomography results, the retrieved density distribution, and the pattern of relocated seismicity exclude the presence of significant shallow magma reservoirs close to the central conduit. These should be located at depth higher than that of the base of the hypocenter volume, as evidenced by previous studies.</p>

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High-resolution x-ray studies of an AXAF high-energy transmission grating

10.1117/12.167191 ◽

1994 ◽

Author(s):

Salim Abdali ◽

Finn E. Christensen ◽

Herbert W. Schnopper ◽

Thomas H. Markert ◽

Daniel Dewey ◽

...

Keyword(s):

High Resolution ◽

High Energy ◽

Energy Transmission ◽

X Ray ◽

Transmission Grating

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Intracellular Energy-Transfer Networks and High-Resolution Respirometry: A Convenient Approach for Studying Their Function

International Journal of Molecular Sciences ◽

10.3390/ijms19102933 ◽

2018 ◽

Vol 19 (10) ◽

pp. 2933 ◽

Cited By ~ 4

Author(s):

Marju Puurand ◽

Kersti Tepp ◽

Aleksandr Klepinin ◽

Lyudmila Klepinina ◽

Igor Shevchuk ◽

...

Keyword(s):

Energy Transfer ◽

High Resolution ◽

Energy Use ◽

Adenosine Monophosphate ◽

High Energy ◽

Functional Coupling ◽

Convenient Approach ◽

Intracellular Energy Transfer ◽

Intracellular Energy ◽

Effect Of Glucose

Compartmentalization of high-energy phosphate carriers between intracellular micro-compartments is a phenomenon that ensures efficient energy use. To connect these sites, creatine kinase (CK) and adenylate kinase (AK) energy-transfer networks, which are functionally coupled to oxidative phosphorylation (OXPHOS), could serve as important regulators of cellular energy fluxes. Here, we introduce how selective permeabilization of cellular outer membrane and high-resolution respirometry can be used to study functional coupling between CK or AK pathways and OXPHOS in different cells and tissues. Using the protocols presented here the ability of creatine or adenosine monophosphate to stimulate OXPHOS through CK and AK reactions, respectively, is easily observable and quantifiable. Additionally, functional coupling between hexokinase and mitochondria can be investigated by monitoring the effect of glucose on respiration. Taken together, high-resolution respirometry in combination with permeabilization is a convenient approach for investigating energy-transfer networks in small quantities of cells and tissues in health and in pathology.

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Oscillator strength study of the excitations of valence-shell of C2H2 by high-resolution inelastic x-ray scattering

Chinese Physics B ◽

10.1088/1674-1056/ac422e ◽

2021 ◽

Author(s):

Qiang Sun ◽

Ya-Wei Liu ◽

Yuan-Chen Xu ◽

Li-Han Wang ◽

Tian-Jun Li ◽

...

Keyword(s):

High Resolution ◽

Theoretical Models ◽

High Energy ◽

Oscillator Strengths ◽

Electron Collision ◽

Valence Shell ◽

X Ray ◽

X Ray Scattering ◽

Theoretical Results ◽

Ray Scattering

Abstract The oscillator strengths of the valence-shell excitations of C2H2 are extremely important for testing theoretical models and studying interstellar gases. In this study, the high-resolution inelastic x-ray scattering (IXS) method is adopted to determine the generalized oscillator strengths (GOSs) of the valence-shell excitations of C2H2 at a photon energy of 10 keV. The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths (OOSs). Through taking a completely different experimental method of the IXS, the present results offer the high energy limit for electron collision to satisfy the first Born approximation (FBA) and cross-check the previous experimental and theoretical results independently. The comparisons indicate that an electron collision energy of 1500 eV is not enough for C2H2 to satisfy the FBA for the large squared momentum transfer, and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.

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