A wide-aperture Cerenkov counter with a water radiator

2000 ◽  
Vol 43 (1) ◽  
pp. 26-30
Author(s):  
O. P. Gavrishchuk ◽  
L. S. Zolin ◽  
V. F. Peresedov
Keyword(s):  
Cerenkov Counter ◽  
Wide Aperture

scholarly journals Elastic wave velocity and electrical conductivity in a brine-saturated rock and microstructure of pores

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Tohru Watanabe ◽  
Miho Makimura ◽  
Yohei Kaiwa ◽  
Guillaume Desbois ◽  
Kenta Yoshida ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Elastic Wave ◽  
Wave Velocity ◽  
High Pressures ◽  
Seismic Velocity ◽  
Volume Fraction ◽  
Elastic Wave Velocity ◽  
Fluid Volume ◽  
Sem Observation ◽  
Wide Aperture

AbstractElastic wave velocity and electrical conductivity in a brine-saturated granitic rock were measured under confining pressures of up to 150 MPa and microstructure of pores was examined with SEM on ion-milled surfaces to understand the pores that govern electrical conduction at high pressures. The closure of cracks under pressure causes the increase in velocity and decrease in conductivity. Conductivity decreases steeply below 10 MPa and then gradually at higher pressures. Though cracks are mostly closed at the confining pressure of 150 MPa, brine must be still interconnected to show observed conductivity. SEM observation shows that some cracks have remarkable variation in aperture. The aperture varies from ~ 100 nm to ~ 3 μm along a crack. FIB–SEM observation suggests that wide aperture parts are interconnected in a crack. Both wide and narrow aperture parts work parallel as conduction paths at low pressures. At high pressures, narrow aperture parts are closed but wide aperture parts are still open to maintain conduction paths. The closure of narrow aperture parts leads to a steep decrease in conductivity, since narrow aperture parts dominate cracks. There should be cracks in various sizes in the crust: from grain boundaries to large faults. A crack must have a variation in aperture, and wide aperture parts must govern the conduction paths at depths. A simple tube model was employed to estimate the fluid volume fraction. The fluid volume fraction of 10−4–10−3 is estimated for the conductivity of 10−2 S/m. Conduction paths composed of wide aperture parts are consistent with observed moderate fluctuations (< 10%) in seismic velocity in the crust.

An electrically triggered 200 kV rail‐gap switch for wide aperture excimer lasers

1984 ◽  
Vol 55 (5) ◽  
pp. 1322-1331 ◽  
Author(s):  
A. Endoh ◽  
S. Watanabe ◽  
M. Watanabe
Keyword(s):  
Excimer Lasers ◽  
Wide Aperture

Fast Data-Driven Readout System for the Wide Aperture Silicon Tracking System of the BM@N Experiment

2021 ◽  
Vol 52 (4) ◽  
pp. 830-834
Author(s):  
D. Dementev ◽  
M. Guminski ◽  
I. Kovalev ◽  
M. Kruszewski ◽  
I. Kudryashov ◽  
...  
Keyword(s):  
Tracking System ◽  
Data Driven ◽  
Readout System ◽  
Wide Aperture

Two-dimensional elastic pseudo-spectral modeling of wide-aperture seismic array data with application to the Wichita Uplift-Anadarko Basin region of southwestern Oklahoma

1990 ◽  
Vol 80 (6A) ◽  
pp. 1677-1695 ◽  
Author(s):  
Ik Bum Kang ◽  
George A. McMechan
Keyword(s):  
Large Scale ◽  
Deep Structure ◽  
Sedimentary Basins ◽  
P Wave ◽  
Two Dimensional ◽  
Anadarko Basin ◽  
Near Surface ◽  
University Of Texas ◽  
Wide Aperture ◽  
The University

Abstract Full wave field modeling of wide-aperture data is performed with a pseudospectral implementation of the elastic wave equation. This approach naturally produces three-component stress and two-component particle displacement, velocity, and acceleration seismograms for compressional, shear, and Rayleigh waves. It also has distinct advantages in terms of computational requirements over finite-differencing when data from large-scale structures are to be modeled at high frequencies. The algorithm is applied to iterative two-dimensional modeling of seismograms from a survey performed in 1985 by The University of Texas at El Paso and The University of Texas at Dallas across the Anadarko basin and the Wichita Mountains in southwestern Oklahoma. The results provide an independent look at details of near-surface structure and reflector configurations. Near-surface (&lt;3 km deep) structure and scattering effects account for a large percentage (&gt;70 per cent) of the energy in the observed seismograms. The interpretation of the data is consistent with the results of previous studies of these data, but provides considerably more detail. Overall, the P-wave velocities in the Wichita Uplift are more typical of the middle crust than the upper crust (5.3 to 7.1 km/sec). At the surface, the uplift is either exposed as weathered outcrop (5.0 to 5.3 km/sec) or is overlain with sediments of up to 0.4 km in thickness, ranging in velocity from 2.7 to 3.4 km/sec, generally increasing with depth. The core of the uplift is relatively seismically transparent. A very clear, coherent reflection is observed from the Mountain View fault, which dips at ≈40° to the southwest, to at least 12 km depth. Velocities in the Anadarko Basin are typical of sedimentary basins; there is a general increase from ≈2.7 km/sec at the surface to ≈5.9 km/sec at ≈16 km depth, with discontinuous reflections at depths of ≈8, 10, 12, and 16 km.

Description of Crassolabium unicum sp. n. (Nematoda: Dorylaimida: Qudsianematidae) from Vietnam

Zootaxa ◽  
2021 ◽  
Vol 4970 (1) ◽  
pp. 189-194
Author(s):  
THI ANH DUONG NGUYEN ◽  
REYES PEÑA-SANTIAGO
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Natural Habitat ◽  
Genital System ◽  
Neck Length ◽  
Caudal Region ◽  
Wide Aperture ◽  
Female Genital System ◽  
Female Genital

Crassolabium unicum sp. n., collected from a natural habitat in Vietnam, is described and illustrated. The new species is characterized by its 0.77–0.94 mm long body, three-layered cuticle, lip region offset by depression and 12–13.5 µm broad, odontostyle 13.5–15 µm long with wide aperture occupying 36–46% of its length, neck 235–260 µm long, pharyngeal expansion 117–131 µm long or occupying 47–52% of total neck length, anterior part of intestine presenting very distinct folds, female genital system didelphic-amphidelphic, uterus simple and 28–43 µm or 0.7–0.9 body diameters, vulva transverse (V = 45–52), prerectum bearing a blind postrectal sac, caudal region short and rounded (21–25 µm, c = 45–61, c’ = 0.6–0.8) with two (dorsal and ventral) lacunae between outer and intermediate cuticle layers, and male unknown. It is compared with the similar representatives of the genus. 

A wide-aperture x-ray source with high intensity and uniformity of radiation

2007 ◽  
Vol 50 (1) ◽  
pp. 95-99
Author(s):  
N. G. Ivanov ◽  
I. N. Konovalov ◽  
V. F. Losev ◽  
Yu. N. Panchenko
Keyword(s):  
High Intensity ◽  
X Ray ◽  
Wide Aperture
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