Experimental Study on the Reaction Zone Distribution of Impact-Induced Reactive Materials

2017 ◽  
Vol 42 (8) ◽  
pp. 896-905 ◽  
Author(s):  
Shunshan Feng ◽  
Chenglong Wang ◽  
Guangyan Huang
Keyword(s):  
Experimental Study ◽  
Reaction Zone ◽  
Reactive Materials

An experimental study of the deflagration-to-detonation transition in granular secondary explosives

1995 ◽  
Vol 448 (1934) ◽  
pp. 439-448 ◽  
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Maximum Density ◽  
Pentaerythritol Tetranitrate ◽  
Safe Storage ◽  
Reactive Materials ◽  
Deflagration To Detonation Transition ◽  
Detonation Transition ◽  
Secondary Explosive

The deflagration-to-detonation transition (DDT) has been studied in prepared columns of granular secondary explosive. The secondary explosives 2- (5-cyanotetrazolato) pentammine cobalt (III) perchlorate (CP) and pentaerythritol tetranitrate (PETN) were chosen for the study due to their known propensity to undergo DDT within a few millimetres of ignition. Confinement of CP columns within polycarbonate and PETN within metallic confinement fitted with slit windows allowed direct high-speed streak photography of the events. Deflagration and detonation velocities and the run-to-detonation lengths were measured as a function of charge pressed density. Ignition of the explosive column was attained thermally through a copper barrier with a gasless pyrotechnic. Deflagration and detonation velocities were seen to depend strongly upon pressed density with both explosives. There appeared to be a maximum density conducive to DDT with both explosives but no minimum with CP. Studies of DDT continue to have interest for the safe storage and use of reactive materials, and for the development of a detonator based on a secondary explosive.

Experimental Study of An A+B→C Reaction-Diffusion System in a Capillary: Crossovers from Reaction to Diffusion-Limited Regimes

1992 ◽  
Vol 290 ◽  
Author(s):  
Yong-Eun Koo ◽  
Raoul Kopelman ◽  
Andrew Yen ◽  
Anna Lin
Keyword(s):  
Experimental Study ◽  
Reaction Zone ◽  
Reaction Front ◽  
Reaction Rate ◽  
Local Reaction ◽  
Reaction Diffusion ◽  
Theoretical Studies ◽  
Boundary Motion ◽  
Diffusion Limited ◽  
Front Dynamics

AbstractContinuing work on elementary A+B→C reactions in capillaries, we study the reaction front dynamics of xylanol orange with Cr3+ in an effectively one-dimentional system with initially separated reactants. This reaction, in contrast to previously studied systems, is not strictly in the diffusion limited regime. i.e. the probability of reaction between species is not unity. Anamalous behavior not seen in the diffusion-limited case has been observed experimentally for the reaction rate, boundary motion, reaction zone width, and local reaction rate. The observed behavior is consistent with recent theoretical studies.

scholarly journals Experimental study of non-oxidized and oxidized bitumen obtained from heavy oil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard Djimasbe ◽  
Eduard A. Galiullin ◽  
Mikhail A. Varfolomeev ◽  
Revo Z. Fakhrutdinov ◽  
Ameen A. Al-Muntaser ◽  
...  
Keyword(s):  
Experimental Study ◽  
Reaction Time ◽  
Reaction Zone ◽  
Heavy Oil ◽  
Softening Point ◽  
Steam Distillation ◽  
Packed Column ◽  
Compressed Air ◽  
Vacuum Residue ◽  
Maximal Rate

AbstractHeavy oil and vacuum residue were used to obtain road bitumen BND 50/70 using two different methods of steam distillation at 323–362 °C and by oxidation, a method using packed column at temperature of 211–220 °C. The obtained residues using two methods steam distillation and oxidation are known as non-oxidized bitumen and oxidized bitumen, respectively. The products were evaluated using different standards including GOST 33133-2014, GOST 22245-90, and ASTM D5. The results showed that the yield of oxidized bitumen reached a maximal rate of 89.59% wt., while that of non-oxidized bitumen is 55% wt. The softening point of oxidized bitumen is 49–57 °C compared to non-oxidized bitumen (46–49 °C). Remarkably, the previous softening point and penetrability of 47–71 points of oxidized bitumen are consistent with norms to BND 50/70 bitumen, according standard. The non-oxidized bitumen has a relatively low softening point and a higher penetration value of 71–275, which refers to BND 200/300 bitumen. Comparatively, the use of a packed column is beneficial than the steam distillation, due to high capability of the nozzles to strengthens contact between feedstock and compressed air in the reaction zone and decreases the reaction time to 4.15 h.

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

Experimental study on the restoration from a tilt-azimuth series for improvement in resolution

1995 ◽  
Vol 53 ◽  
pp. 636-637
Author(s):  
Norio Baba ◽  
Norihiko Ichise ◽  
Syunya Watanabe
Keyword(s):  
Experimental Study ◽  
Spherical Aberration ◽  
Incident Beam ◽  
Optical Parameters ◽  
Beam Tilting ◽  
Illumination Method ◽  
Restoration Method ◽  
Illumination Mode

The tilted beam illumination method is used to improve the resolution comparing with the axial illumination mode. Using this advantage, a restoration method of several tilted beam images covering the full azimuthal range was proposed by Saxton, and experimentally examined. To make this technique more reliable it seems that some practical problems still remain. In this report the restoration was attempted and the problems were considered. In our study, four problems were pointed out for the experiment of the restoration. (1) Accurate beam tilt adjustment to fit the incident beam to the coma-free axis for the symmetrical beam tilting over the full azimuthal range. (2) Accurate measurements of the optical parameters which are necessary to design the restoration filter. Even if the spherical aberration coefficient Cs is known with accuracy and the axial astigmatism is sufficiently compensated, at least the defocus value must be measured. (3) Accurate alignment of the tilt-azimuth series images.

Sign in / Sign up

Export Citation Format

Share Document