Cast Double Base: Propellant designed to meet internal ballistic requirements

2011 ◽  
Author(s):  
C. Rousseau ◽  
M. Leslie ◽  
G. Steyn ◽  
Robin Pretner
Keyword(s):  
Internal Ballistic ◽  
Double Base

Réalisation de moulages en split-cast (double base engrenée)

1984 ◽  
Vol 18 (2) ◽  
pp. 249-251
Author(s):  
Rudolf Slavicek ◽  
Heinz Mack
Keyword(s):  
Double Base

Two Lower Bounds for Shortest Double-Base Number System

2015 ◽  
Vol E98.A (6) ◽  
pp. 1310-1312 ◽  
Author(s):  
Parinya CHALERMSOOK ◽  
Hiroshi IMAI ◽  
Vorapong SUPPAKITPAISARN
Keyword(s):  
Lower Bounds ◽  
Number System ◽  
Base Number ◽  
Double Base

IGNITER COMPOSITIONS FOR LOVA AND DOUBLE-BASE PROPELLANTS CONTAINING KDN

2019 ◽  
Vol 18 (2) ◽  
pp. 171-183
Author(s):  
Volker Weiser ◽  
Stefan Kelzenberg ◽  
Sebastian Knapp ◽  
A. Koleczko ◽  
E. Roth
Keyword(s):  
Double Base

scholarly journals Telomerase RNA Template Mutations Reveal Sequence-Specific Requirements for the Activation and Repression of Telomerase Action at Telomeres

2000 ◽  
Vol 20 (8) ◽  
pp. 2941-2948 ◽  
Author(s):  
John C. Prescott ◽  
Elizabeth H. Blackburn
Keyword(s):  
Enzymatic Activity ◽  
Activity Levels ◽  
Telomeric Dna ◽  
Telomere Shortening ◽  
Telomere Elongation ◽  
Telomere Binding Protein ◽  
Telomere Function ◽  
Double Base ◽  
Telomere Lengthening

ABSTRACT Telomeric DNA is maintained within a length range characteristic of an organism or cell type. Significant deviations outside this range are associated with altered telomere function. The yeast telomere-binding protein Rap1p negatively regulates telomere length. Telomere elongation is responsive to both the number of Rap1p molecules bound to a telomere and the Rap1p-centered DNA-protein complex at the extreme telomeric end. Previously, we showed that a specific trinucleotide substitution in the Saccharomyces cerevisiae telomerase gene (TLC1) RNA template abolished the enzymatic activity of telomerase, causing the same cell senescence and telomere shortening phenotypes as a complete tlc1 deletion. Here we analyze effects of six single- and double-base changes within these same three positions. All six mutant telomerases had in vitro enzymatic activity levels similar to the wild-type levels. The base changes predicted from the mutations all disrupted Rap1p binding in vitro to the corresponding duplex DNAs. However, they caused two classes of effects on telomere homeostasis: (i) rapid, RAD52-independent telomere lengthening and poor length regulation, whose severity correlated with the decrease in in vitro Rap1p binding affinity (this is consistent with loss of negative regulation of telomerase action at these telomeres; and (ii) telomere shortening that, depending on the template mutation, either established a new short telomere set length with normal cell growth or was progressive and led to cellular senescence. Hence, disrupting Rap1p binding at the telomeric terminus is not sufficient to deregulate telomere elongation. This provides further evidence that both positive and negativecis-acting regulators of telomerase act at telomeres.

Definition of a JA-2 Equivalent Propellant to be Produced by Continuous Solventless Extrusion

2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Thelma G. Manning ◽  
Joseph Leone ◽  
Martijn Zebregs ◽  
Dinesh R. Ramlal ◽  
Chris A. van Driel
Keyword(s):  
Extrusion Process ◽  
Continuous Manufacturing ◽  
Twin Screw Extrusion ◽  
Extrusion Processing ◽  
Roll Mill ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Ballistic Properties ◽  
Definition Of ◽  
Double Base

In order to eliminate residual solvents in ammunition and to reduce the emissions of volatile organic compounds to the atmosphere, the U.S. Army ARDEC has teamed with TNO in developing a new process for the production of solventless propellant for tank ammunition. To reduce the costs of solventless propellants production, shear roll mill and continuous extrusion processing was investigated. As described in this paper JA-2 a double base propellant cannot be processed without solvent by the extrusion process. An alternative JA-2 equivalent propellant was defined. The aim of this work is to demonstrate the manufacturing of this propellant by solventless continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior ballistic properties of the gun propellant and utilizing a continuous manufacturing process. Processing conditions were established, and the propellant was manufactured accordingly. The extruded propellant has the desired properties, which resulted in a comparable gun performance as the conventional JA-2 propellant.

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