Physical Foundation of Interior Ballistics

Ballistics ◽  
2013 ◽  
pp. 25-86
Keyword(s):  
Interior Ballistics ◽  
Physical Foundation

Physical Foundation of Interior Ballistics

Ballistics ◽  
2018 ◽  
pp. 7-66
Author(s):  
Donald E. Carlucci ◽  
Sidney S. Jacobson
Keyword(s):  
Interior Ballistics ◽  
Physical Foundation

A Physically Based Constitutive Description for Nonproportional Cyclic Plasticity

1991 ◽  
Vol 113 (2) ◽  
pp. 254-262 ◽  
Author(s):  
Fan Jinghong ◽  
Peng Xianghe
Keyword(s):  
Stress Responses ◽  
Sudden Change ◽  
Dislocation Cell ◽  
Cyclic Plasticity ◽  
Cyclic Process ◽  
Planar Slip ◽  
History Effects ◽  
Physically Based ◽  
Physical Foundation ◽  
Two Parameters

The hardening behavior of materials in nonproportional cyclic process is related to the internal changes of materials, such as dislocation cell for wary slip material and ladder or vein substructures for planar slip material. The multiplicatively separated form of hardening function f, in terms of nonhardening region proposed by Ohno [1], and the measure of nonproportionality A proposed by Banallal and Marquis in 1987 [2], is then explained on this physical foundation. The new contributions of this hardening function are: (a) two parameters (f2 and f3) dependent on A are used to differentiate between the influence of latent hardening realized by a sudden change of loading direction, and hereditary hardening associated with nonproportional loading, (b) a general differential form fi (i = 1,2,3) is proposed, and memorial parameters a1 and a3 are introduced to describe different deformation history effects for wary and planar slip materials, (c) different hardening mechanisms through fi are embedded into thermomechanically constitutive relation. The stress responses of 304 and 316 stainless steels subjected to biaxial nonproportional loadings at room temperature are analyzed and compared with the experimental results obtained by Chaboche [3], Tanaka [4, 5] and Ohno [1].

The Effect of In-School Saccadic Training on Reading Fluency and Comprehension in First and Second Grade Students

2016 ◽  
Vol 32 (1) ◽  
pp. 104-111 ◽  
Author(s):  
David Dodick ◽  
Amaal J. Starling ◽  
Jennifer Wethe ◽  
Yi Pang ◽  
Leonard V. Messner ◽  
...  
Keyword(s):  
Eye Movements ◽  
Reading Fluency ◽  
Visual Processing ◽  
Second Grade ◽  
Control Group ◽  
Second Grade Students ◽  
Fluency And Comprehension ◽  
Physical Foundation ◽  
Study Participants ◽  
And Control

Efficient eye movements provide a physical foundation for proficient reading skills. We investigated the effect of in-school saccadic training on reading performance. In this cross-over design, study participants (n = 327, 165 males; mean age [SD]: 7 y 6 mo [1y 1 mo]) were randomized into treatment and control groups, who then underwent eighteen 20-minute training sessions over 5 weeks using King-Devick Reading Acceleration Program Software. Pre- and posttreatment reading assessments included fluency, comprehension, and rapid number naming performance. The treatment group had significantly greater improvement than the control group in fluency (6.2% vs 3.6%, P = .0277) and comprehension (7.5% vs 1.5%, P = .0002). The high-needs student group significantly improved in fluency ( P < .001) and comprehension ( P < .001). We hypothesize these improvements to be attributed to the repetitive practice of reading-related eye movements, shifting visuospatial attention, and visual processing. Consideration should be given to teaching the physical act of reading within the early education curriculum.

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