scholarly journals Performance of a commercial backscatter instrument adapted for noncontacting areal density measurements on small-diameter surfaces

1980 ◽  
Author(s):  
P B Higgins
Keyword(s):  
Small Diameter ◽  
Areal Density ◽  
Density Measurements

scholarly journals Radiographic areal density measurements on the OMEGA EP laser system

2021 ◽  
Vol 92 (5) ◽  
pp. 053901
Author(s):  
Camelia V. Stan ◽  
Alison M. Saunders ◽  
Matthew P. Hill ◽  
Tom Lockard ◽  
Kyle Mackay ◽  
...  
Keyword(s):  
Laser System ◽  
Areal Density ◽  
Density Measurements

Time-Resolved Areal-Density Measurements with Proton Spectroscopy in Spherical Implosions

2003 ◽  
Vol 90 (13) ◽  
Author(s):  
V. A. Smalyuk ◽  
P. B. Radha ◽  
J. A. Delettrez ◽  
V. Yu. Glebov ◽  
V. N. Goncharov ◽  
...  
Keyword(s):  
Areal Density ◽  
Proton Spectroscopy ◽  
Time Resolved ◽  
Density Measurements

scholarly journals 5000 MHz Flux Densities and Spectra for 325 Small-diameter Radio Sources at Low Galactic Latitudes

1975 ◽  
Vol 28 (5) ◽  
pp. 633 ◽  
Author(s):  
JL Caswell ◽  
RF Haynes ◽  
DH Clark
Keyword(s):  
Flux Density ◽  
Small Diameter ◽  
Radio Sources ◽  
Density Measurements

Flux density measurements at 5000 MHz are presented for 325 of the small-diameter sources detected in the Molonglo 408 MHz galactic survey. By investigating the spectra we show that probably between 10 % and 15 % of the sources are galactic and the remainder extragalactic.

scholarly journals In situcalibration of the Gamma Reaction History instrument using reference samples (“pucks”) for areal density measurements

2013 ◽  
Vol 59 ◽  
pp. 13019 ◽  
Author(s):  
N.M. Hoffman ◽  
H.W. Herrmann ◽  
Y.H. Kim ◽  
H.H. Hsu ◽  
C.J. Horsfield ◽  
...  
Keyword(s):  
Areal Density ◽  
Density Measurements ◽  
Reference Samples

The energy-absorbing characteristics of tubular sandwich structures

2021 ◽  
pp. 109963622110204
Author(s):  
HZ Jishi ◽  
RA Alia ◽  
WJ Cantwell
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Small Diameter ◽  
Areal Density ◽  
External Energy ◽  
Composite Tubes ◽  
Longitudinal Splitting ◽  
Energy Absorbing ◽  
Tubular Array ◽  
Tubular Arrays

The energy-absorbing response of sandwich structures with exceptionally high levels of energy absorption is investigated. The sandwich panels are produced by fixing small composite tubes onto metal facings with surface features that reflect the internal geometry of the tubing. Small diameter tubes are employed to manufacture the cores, since it is well established that the specific energy absorption (SEA) characteristics of a composite tube increase as the inner dimension (diameter or wall-to-wall) to thickness ratio decreases. Tests have been undertaken on tubular arrays based on both circular and square composite tubes. The effect of varying the areal density of the tubular array within the core was investigated by systematically increasing the number of tubes from one to nine. An examination of the composites during the crushing process indicated that all of the tubes failed in a splaying process, involving significant fracturing of fibers and longitudinal splitting. The measured values of SEA remained relatively constant in most cases as the areal density of the tubular arrangement was increased, suggesting that cores could readily be designed to absorb known levels of applied external energy. Arrays based on circular tubes offered higher energy-absorbing characteristics than their square counterparts, with values in excess of 100 kJ/kg being recorded in some cases. It is believed that these tubular sandwich structures offer potential for use in components that are subjected to extreme dynamic loading, such as those associated with impact and blast.

Formation ofWell-defined Nanocolumns by Ion Tracking Lithography

2003 ◽  
Vol 777 ◽  
Author(s):  
T.E. Felter ◽  
R. G. Musket ◽  
J. Macaulay ◽  
R. J. Contolini ◽  
P. C. Searson
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Small Diameter ◽  
Physical Property ◽  
Areal Density ◽  
Mold Material ◽  
Sufficient Energy ◽  
Quantum Behavior ◽  
Low Dimensional ◽  
And Control

AbstractLow dimensional systems on the nanometer scale afford a wealth of interesting possibilities including highly anisotropic behavior and quantum effects. Nanocolumns permit electrical and mechanical contact, yet benefit from two confined dimensions. This confinement leads to new optical, mechanical, electrical, chemical, and magnetic properties. We construct nanocolumn arrays with precise definition and independent control of diameter, length, orientation, areal density and composition so that geometry can be directly correlated to the quantum physical property of interest. The precision and control are products of the fabrication technique that we use. The process starts with an ion of sufficient energy to “track” a dielectric such as a film applied uniformly onto a substrate. The energy loss of the ion alters chemical bonding in the dielectric along the ion's straight trajectory. A suitable etchant quickly dissolves the latent tracks leaving high aspect ratio holes of small diameter (∼10nm) penetrating a film as thick as several microns. These small holes are interesting and useful in their own right and can be made to any desired size by continuing the etching process. Moreover, they serve as molds for electrochemical filling. After this electrodeposition, the mold material can be removed leaving the columns firmly attached to the substrate at the desired orientation. A variety of structures can be envisioned with these techniques. As examples, we have created arrays of Ni and of Pt nanocolumns (∼ 60 nm diameter and ∼ 600 nm long) oriented perpendicular to the substrate. The high aspect ratio and small diameter of the columns enables easy observation of quantum behavior, namely efficient electron field emission and Fowler Nordheim behavior.

scholarly journals Radiochemistry measurements on the Phebus laser

1992 ◽  
Vol 10 (4) ◽  
pp. 585-597 ◽  
Author(s):  
D. Schirmann ◽  
C. Bayer ◽  
J. P. Garçonnet ◽  
D. Juraszek ◽  
A. Bertin ◽  
...  
Keyword(s):  
Blue Light ◽  
Areal Density ◽  
Liquid Density ◽  
Density Measurements ◽  
Fuel Density ◽  
Neutron Diagnostics

We are developing neutron diagnostics to characterize the implosions performed with the Phebus laser, operating at 5 kJ blue light delivered in 1·3 ns. For measuring the glass pusher areal density, (ρΔR), of the target, a silicon radiochemistry diagnostic has been implemented and is currently being used. We describe the diagnostic and its performance. Pusher areal density measurements, (ρΔR) and calculated values of fuel density are given. Deuterium (D)-tritium (T) final densities as high as 100 × D-T liquid density (20 g/cm3) have been achieved.

The crushing characteristics of reinforced Nomex honeycomb

2018 ◽  
Vol 37 (20) ◽  
pp. 1267-1276 ◽  
Author(s):  
RA Alia ◽  
S Rao ◽  
R Umer ◽  
J Zhou ◽  
C Zheng ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Compression Strength ◽  
Small Diameter ◽  
Areal Density ◽  
Mechanical Tests ◽  
Stable Model ◽  
Specific Energy Absorption ◽  
Nomex Honeycomb ◽  
Energy Absorbing

A Nomex honeycomb core has been reinforced with small diameter composite rods and tubes in order to enhance its compression properties and energy-absorbing characteristics. The influence of the areal density of the rods and tubes on the strength and energy-absorbing properties of the reinforced honeycomb was investigated by introducing increasing numbers of rods/tubes in square samples with bonded composite skins. An initial series of crushing tests on arrangements of small tubes and rods resulted in a stable model of failure yielding specific energy absorption values of approximately 45 kJ/kg for the tube and rod-based structures. A subsequent observation of the failed tubes highlighted the similar failure processes to those observed previously following the tests on much larger composite cylinders. Mechanical tests on the Nomex cores have shown that the compression strength and energy-absorbing characteristics of the reinforced honeycombs increase rapidly with increasing composite reinforcement. At low and intermediate values of core density, the rod and tube-reinforced cores exhibited similar properties, in terms of their compression strengths and specific energy absorption, an effect that is likely to be due to the dominance of the heavier Nomex core in these samples. At higher densities, the rod-reinforced systems tended to out-perform their tube-reinforced counterparts. Tests at impact rates of strain have shown that the compression strength and energy-absorbing capabilities of the reinforced cores are higher under the dynamic conditions, with the rod-reinforced cores offering values of specific energy absorption as high as 78 kJ/kg.

Sign in / Sign up

Export Citation Format

Share Document