A sheet impedance approximation for electrically thick material shields

2002 ◽  
Vol 50 (4) ◽  
pp. 435-443 ◽  
Author(s):  
E.H. Newman
Keyword(s):  
Impedance Approximation ◽  
Thick Material

scholarly journals Probing the circumnuclear absorbing medium of the buried AGN in NGC 1068 through NuSTAR observations

2020 ◽  
Vol 492 (3) ◽  
pp. 3872-3884 ◽  
Author(s):  
A Zaino ◽  
S Bianchi ◽  
A Marinucci ◽  
G Matt ◽  
F E Bauer ◽  
...  
Keyword(s):  
Time Scales ◽  
Line Of Sight ◽  
Nuclear Region ◽  
Spectral Variability ◽  
Absorbing Medium ◽  
X Ray ◽  
Innermost Part ◽  
Monitoring Campaign ◽  
Ngc 1068 ◽  
Thick Material

ABSTRACT We present the results of the latest NuSTAR monitoring campaign of the Compton-thick Seyfert 2 galaxy NGC 1068, composed of four ∼50 ks observations performed between 2017 July and 2018 February to search for flux and spectral variability on time-scales from 1 to 6 months. We detect one unveiling and one eclipsing event with time-scales less than 27 and 91 d, respectively, ascribed to Compton-thick material with NH = (1.8 ± 0.8) × 1024 and ≥ (2.4 ± 0.5) × 1024 cm−2 moving across our line of sight. This gas is likely located in the innermost part of the torus or even further inward, thus providing further evidence of the clumpy structure of the circumnuclear matter in this source. Taking advantage of simultaneous Swift–XRT observations, we also detected a new flaring ULX, at a distance d ∼ 30 arcsec (i.e. ∼2 kpc) from the nuclear region of NGC 1068, with a peak X-ray intrinsic luminosity of (3.0 ± 0.4) × 1040 erg s−1 in the 2–10 keV band.

Sensing and Control of Double-Sided Arc Welding Process

2002 ◽  
Vol 124 (3) ◽  
pp. 695-701 ◽  
Author(s):  
Y. M. Zhang ◽  
S. B. Zhang ◽  
M. Jiang
Keyword(s):  
Arc Welding ◽  
Current Practice ◽  
Welding Process ◽  
Butt Joint ◽  
Large Structures ◽  
Arc Welding Process ◽  
And Control ◽  
Number Of Passes ◽  
Welding Productivity ◽  
Thick Material

The welding industry is driven to improve productivity without sacrificing quality. For thick material welding, the current practice is to use backing or multiple passes. The laser welding process, capable of achieving deep narrow penetration, can significantly improve welding productivity for such applications by reducing the number of passes. However, its competitiveness in comparison with traditional arc welding is weakened by its high cost, strict fit-up requirement, and difficulty in welding large structures. In this work, a different method, referred to as double-sided arc welding (DSAW) is developed to improve the arc concentration for arc welding. A sensing and control system is developed to achieve deep narrow penetration under variations in welding conditions. Experiments verified that the pulsed keyhole DSAW system developed is capable of achieving deep narrow penetration on a 1/2 inch thick square butt joint in a single pass.

Simulation of conversion profiles and temperature distributions within dimethacrylate thick material during photopolymerization

1999 ◽  
Vol 148 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Laurence Lecamp ◽  
Philippe Lebaudy ◽  
Boulos Youssef ◽  
Claude Bunel
Keyword(s):  
Temperature Distributions ◽  
Thick Material

Influence of Microstructural Variation in Thick Section Steels on the Characterisation of Fracture Toughness Using Sub-Size Specimens

2019 ◽  
Author(s):  
Philippa Moore ◽  
Borislava Yordanova ◽  
Yong Lu ◽  
Yin Jin Janin
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Plate Thickness ◽  
High Strength ◽  
Steel Plates ◽  
Full Thickness ◽  
Master Curve Method ◽  
Sampling Locations ◽  
Curve Method ◽  
Thick Material

Abstract The challenges of performing full-thickness fracture toughness tests on steel plates of 100mm thickness and greater means that the use of sub-size specimens is desirable. In this work, 100mm thick parent plate of S690 high strength steel was characterised using SENB fracture toughness specimens with thickness of 12mm, 25mm, 50mm and 100mm. Sub-size specimens were extracted at two different locations through the plate thickness; mid-wall and quarter wall. Sufficient specimens were tested to apply the Master Curve method in ASTM E1921 to predict the behaviour of 100mm thick material from each set of sub-size specimens. The through-thickness microstructural variation in these heavy-wall steel plates meant that significantly different predictions of full-thickness fracture toughness were obtained from the two sampling locations. However, when sampled from the mid-wall location, sub-size specimens down to 25mm thick were able to conservatively predict full-thickness fracture toughness using Master Curve methods.

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