scholarly journals Supplemental Material: Protolith affiliation and tectonometamorphic evolution of the Gurla Mandhata core complex, NW Nepal Himalaya

2021 ◽  
Author(s):  
L. Godin ◽  
et al.
Keyword(s):  
Ion Microprobe ◽  
Scattered Electron ◽  
Core Complex ◽  
Nepal Himalaya ◽  
X Ray ◽  
Analytical Results ◽  
Analytical Procedures

<div>Analytical procedures, back-scattered electron imagery, X-ray ion microprobe chemical maps, geochemistry results, and U-Th/Pb analytical results.</div>

scholarly journals Supplemental Material: Protolith affiliation and tectonometamorphic evolution of the Gurla Mandhata core complex, NW Nepal Himalaya

2021 ◽  
Author(s):  
L. Godin ◽  
et al.
Keyword(s):  
Ion Microprobe ◽  
Scattered Electron ◽  
Core Complex ◽  
Nepal Himalaya ◽  
X Ray ◽  
Analytical Results ◽  
Analytical Procedures

<div>Analytical procedures, back-scattered electron imagery, X-ray ion microprobe chemical maps, geochemistry results, and U-Th/Pb analytical results.</div>

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 314-315
Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Equilibrium Phase ◽  
Icosahedral Symmetry ◽  
Ion Microprobe ◽  
X Ray ◽  
Cu Alloys ◽  
Two Phases ◽  
The University ◽  
Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

scholarly journals Resonant Effect of High-Energy Electron–Positron Pairs Production in Collision of Ultrarelativistic Electrons with an X-ray Electromagnetic Wave

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 210
Author(s):  
Georgii K. Sizykh ◽  
Sergei P. Roshchupkin ◽  
Victor V. Dubov
Keyword(s):  
High Energy ◽  
Energy Electron ◽  
Opening Angle ◽  
High Energy Electron ◽  
Scattered Electron ◽  
Differential Probability ◽  
X Ray ◽  
Electron Positron ◽  
Pulsar Radiation ◽  
Resonant Effect

The process of resonant high-energy electron–positron pairs production by electrons in an X-ray pulsar electromagnetic field is studied theoretically. Under the resonance conditions, the second-order process under consideration effectively reduces into two sequential first-order processes: X-ray-stimulated Compton effect and X-ray–stimulated Breit–Wheeler process. The kinematics of the process is studied in detail: the dependencies of the energy of the scattered electron on its outgoing angle and the energies of the particles of the pair on the outgoing angle of the scattered electron and the opening angle of the pair are obtained. The analysis of the number of different possible particles energies values in the entire range of the angles is also carried out, according to which the energies of the particles of the pair can take up to eight different values at a fixed outgoing angle of the scattered electron and opening angle of the pair. The estimate of the resonant differential probability per unit time of the process, which reaches the maximum value of 24 orders of the value of the non-resonant differential probability per unit time, is obtained. The angular distribution of the differential probability per unit time of the process is analyzed, particularly for the case of high-energy positrons presenting in pulsar radiation.

scholarly journals Supplemental Material: An intracontinental orogen exhumed by basement-slice imbrication in the Longmenshan Thrust Belt of the Eastern Tibetan Plateau

2021 ◽  
Author(s):  
Zhenhua Xue ◽  
Wei Lin ◽  
et al.
Keyword(s):  
Tibetan Plateau ◽  
Energy Dispersive ◽  
Thrust Belt ◽  
Eastern Tibetan Plateau ◽  
X Ray ◽  
Related Energy ◽  
Analytical Results ◽  
Longmenshan Thrust Belt ◽  
Step Heating

Three figures (Figs. S1–S3) and two tables (Tables S1–S2). Figure S1: Images and related Energy Dispersive X-ray spectra to show that quartz melts infilled in feldspar crack; Figure S2: Features of samples selected for 40Ar-39Ar dating; Figure S3: Inverse isochron lines that yield false initial 40Ar/39Ar ratio; Table S1: Detailed SIMS U-Pb zircon results of sample CX48; Table S2: Detailed 40Ar/39Ar VG3600 Furnace Step-Heating Analytical Results.

Parallel Monte Carlo Simulation Using Desktop Computers

1999 ◽  
Vol 5 (S2) ◽  
pp. 80-81
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Scattering ◽  
Information Needs ◽  
Image Interpretation ◽  
Scattered Electron ◽  
Electron Trajectories ◽  
X Ray ◽  
Desktop Computers ◽  
Computationally Expensive

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected x-ray and electron signals falls into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation. Such problems are ideally suited to parallel multicomputers, where a manager process distributes the computational burden over a large number of nodes.

scholarly journals Refinement of the x-ray structure of the RC LH1 core complex from Rhodopseudomonas palustris by single-molecule spectroscopy

2007 ◽  
Vol 104 (51) ◽  
pp. 20280-20284 ◽  
Author(s):  
M. F. Richter ◽  
J. Baier ◽  
J. Southall ◽  
R. J. Cogdell ◽  
S. Oellerich ◽  
...  
Keyword(s):  
Single Molecule ◽  
Rhodopseudomonas Palustris ◽  
Single Molecule Spectroscopy ◽  
Core Complex ◽  
X Ray

Crystallization and preliminary X-ray diffraction studies on the N-utilizing substance-B (NusB) from Mycobacterium tuberculosis

2000 ◽  
Vol 56 (1) ◽  
pp. 64-66 ◽  
Author(s):  
B. Gopal ◽  
R. A. Cox ◽  
M. J. Colston ◽  
G. G. Dodson ◽  
S. J. Smerdon ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Ribosomal Rna ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Hanging Drop ◽  
Core Complex ◽  
Unit Cell Parameters ◽  
Data Set ◽  
X Ray ◽  
Cell Parameters

N-utilizing substance B (NusB) is a protein which forms part of a complex assembly in transcriptional antitermination in Mycobacterium tuberculosis. It forms a heterodimer with the product of the NusE gene (identical to the ribosomal protein S10) and mediates the process of transcriptional antitermination by forming the core complex with the nut site of the ribosomal RNA along with other protein factors. NusB has been cloned and overexpressed in Escherichia coli and crystallized using the hanging-drop vapour-diffusion method. The space group is P212121, with unit-cell parameters a = 46.6, b = 64.2, c = 90.1 Å. A native data set complete to 1.6 Å resolution has been collected from a single crystal.

SPECIFIC FEATURES OF ULTRASOFT X-RAY BREMSSTRAHLUNG ON SCATTERING OF INTERMEDIATE ENERGY ELECTRONS BY ARGON ATOMS

2002 ◽  
Vol 09 (01) ◽  
pp. 651-654 ◽  
Author(s):  
E. V. GNATCHENKO ◽  
A. A. TKACHENKO ◽  
E. T. VERKHOVTSEVA
Keyword(s):  
Electron Energy ◽  
Intermediate Energy ◽  
Direct Proportion ◽  
Scattered Electron ◽  
Dynamic Polarizability ◽  
X Ray ◽  
Energy Approximation ◽  
Subsequent Rise ◽  
Bremsstrahlung Intensity ◽  
Made In

The differential spectra of bremsstrahlung on scattering of intermediate energy (0.3–2 keV) electrons by Ar atoms are studied. The measurements are made in the 6.5–10 nm ultrasoft X-ray region (the photon energy region 190.8–124 eV), where the dynamic polarizability of an Ar atom is low. For each of the wavelengths studied it is found that as the electron energy is increased from 0.3 to 0.7 keV, the bremsstrahlung intensity increases first in direct proportion to the square root of the scattered electron energy and then decreases in inverse proportion to it on subsequent rise in the energy from 0.8 to 2 keV. The increase in the bremsstrahlung intensity with electron energy is explained in terms of the low-energy approximation by the contributions of the opened channels of atom excitation and ionization that accompany the braking effect.

scholarly journals Parallel Monte Carlo Simulation Using Desktop Computers

2000 ◽  
Vol 8 (2) ◽  
pp. 34-35
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Scattering ◽  
Information Needs ◽  
Image Interpretation ◽  
Scattered Electron ◽  
Electron Trajectories ◽  
X Ray ◽  
Desktop Computers ◽  
Computationally Expensive

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected xray and electron signals fall into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation.

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