CO laser gain measurements in acetylene oxygen detonation products

1978 ◽  
Vol 56 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Bruce A. Armstrong ◽  
Boye Ahlborn ◽  
Shigeo Mikoshiba ◽  
John Tulip
Keyword(s):  
Supersonic Nozzle ◽  
Reaction Products ◽  
Detonation Products ◽  
Co Laser ◽  
Laser Gain ◽  
Hot Gas

We have observed gain for CO laser transitions in the reaction products of an acetylene oxygen detonation after expanding the hot gas by means of a supersonic nozzle.

Expansion of the detonation products of lead azide via a supersonic nozzle

Shock Waves ◽  
1994 ◽  
Vol 4 (1) ◽  
pp. 11-14
Author(s):  
Y. Tzuk ◽  
I. Bar ◽  
S. Rosenwaks
Keyword(s):  
Supersonic Nozzle ◽  
Lead Azide ◽  
Detonation Products

Energy output of insensitive high explosives by measuring the detonation products

1992 ◽  
Vol 339 (1654) ◽  
pp. 335-343
Keyword(s):  
Ambient Pressure ◽  
Physical Structure ◽  
Carbon Residue ◽  
Energy Output ◽  
Reaction Products ◽  
Detonation Products ◽  
High Explosives ◽  
Gaseous Reaction ◽  
Cyclotrimethylene Trinitramine ◽  
Detonation Reaction

The detonation products of high explosives are dependent on pressure and also on the confinement under which the detonation reaction proceeds. To determine the detonation products of less sensitive high explosives such as trinitrotoluene/ nitroguanidine and polymer bonded explosive charges with polybutadiene binder containing cyclotrimethylene trinitramine, together with or without aluminium, experiments have been performed in a stainless steel chamber of a volume of 1.5 m 3 . These experiments were done under different ambient argon pressures up to 0.3 MPa. Gaseous reaction products were analysed by mass spectrometry and chemiluminescence analysis. Solid reaction products were analysed for measuring the carbon residue or unreacted aluminium. It was found that the detonation products were highly dependent on the ambient pressure of argon. The most important changes of the reaction products and therefore also of the energy output were found between vacuum and atmospheric pressure of argon. With increasing pressure, H 2 and CO decrease and CO 2 , H 2 , C 8 , NH 3 , HCN and CH 4 increase together with the reaction enthalpy. By analysing the physical structure of the carbon residue, diamonds have been observed between 4 and 7 nm in diameter.

scholarly journals Estimating the consequences of an explosion on critical infrastructure

2020 ◽  
pp. 114-123
Author(s):  
Andrzej Papliński
Keyword(s):  
Physical Environment ◽  
Critical Infrastructure ◽  
Explosive Loading ◽  
Detonation Properties ◽  
Reaction Products ◽  
Condensed Explosive ◽  
Detonation Products ◽  
Loading Effects ◽  
Detonation Energy ◽  
Good Agreement

The study is an analysis estimating the threat arising from the detonation products of a condensed explosive on the physical environment. It presents an analysis of fundamental detonation properties such as detonation height and Mach wave formation, related to their loading effects on critical infrastructure. Analytical equations as well as modelling were investigated to predict the effects of explosive loading on surroundings and people. Comparisons were made between the results from calculations with those of the equations, based on approximated experimental data. It was concluded that when applying the JWL equation of state to the reaction products of TNT, good agreement was obtained between modeling and experimental results for the detonation energy derived with the aid of thermodynamic calculations.

scholarly journals A Coupled Two-Domain Approach for Transpiration Cooling

2020 ◽  
pp. 33-49
Author(s):  
Valentina König ◽  
Michael Rom ◽  
Siegfried Müller
Keyword(s):  
Porous Medium ◽  
Gas Flow ◽  
Porous Ceramic ◽  
Supersonic Nozzle ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Transpiration Cooling ◽  
Thrust Chamber ◽  
Hot Gas ◽  
Coupling Conditions

Abstract Transpiration cooling is an innovative cooling concept where a coolant is injected through a porous ceramic matrix composite (CMC) material into a hot gas flow. This setting is modeled by a two-domain approach coupling two models for the hot gas domain and the porous medium to each other by coupling conditions imposed at the interface. For this purpose, appropriate coupling conditions, in particular accounting for local mass injection, are developed. To verify the feasibility of the two-domain approach numerical simulations in 3D are performed for two different application scenarios: a subsonic thrust chamber and a supersonic nozzle.

Numerical studies of the fundamental and first-overtone transitions CO laser gain excited in slab rf discharge

2002 ◽  
Author(s):  
W. N. Baldwin ◽  
Gordon D. Hager ◽  
Andrei A. Ionin ◽  
Igor Kochetov ◽  
Yuri B. Konev ◽  
...  
Keyword(s):  
Rf Discharge ◽  
Co Laser ◽  
Laser Gain ◽  
Numerical Studies

Theoretical Assessment of Turbocharged Pulse Detonation Engine Performance at Various Flight Conditions

2020 ◽  
Author(s):  
Pereddy Nageswara Reddy
Keyword(s):  
Unit Area ◽  
Pressure Ratio ◽  
Supersonic Nozzle ◽  
Operating Conditions ◽  
Pulse Detonation Engine ◽  
Detonation Products ◽  
Pulse Detonation ◽  
Compressor Pressure Ratio ◽  
Detonation Engine ◽  
Specific Thrust

Abstract A typical Pulse Detonation Engine (PDE) cycle of operation includes three basic processes: initiation and propagation of detonation wave in the Detonation Chamber (DC); a quasi-steady exhaust of detonation products from the DC at varying pressure through the supersonic nozzle; and a steady exhaust of remained detonation products at constant pressure through the nozzle while filling the DC with fresh air. In the present work, a novel method of Turbo-charging is proposed to increase the inlet pressure/density of fresh air fed into the DC in each cycle so as to increase the thrust developed per unit area of DC. The thermodynamic cycle of operation of Turbocharged Pulse Detonation Engine (TPDE) is analyzed based on quasi-steady state one dimensional formulation, and a computer code is developed in MATLAB to simulate the cycle performance at different compressor pressure ratios. Thrust per unit area of DC, the specific thrust and the fuel-based specific impulse are estimated at various flight conditions at different pressure ratios by considering C2H4/air as the fuel-oxidizer. The net thrust developed per unit area of DC increases with an increase in compressor pressure ratio, up to the pressure ratio of 4.0, at all flight conditions. The compressor pressure ratio of about 2.0 is observed to be optimum pressure ratio as TPDE develops nearly the same air-based specific thrust at this pressure ratio irrespective of flight operating conditions.

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

Precipitation in silicon: Microanalysis

1988 ◽  
Vol 46 ◽  
pp. 474-475
Author(s):  
R.W. Carpenter
Keyword(s):  
Transition Metals ◽  
Spatial Resolution ◽  
Thin Foil ◽  
Precipitation Reaction ◽  
High Current ◽  
Reaction Products ◽  
Carbon And Nitrogen ◽  
Dielectric Layers ◽  
Precipitation Processes ◽  
Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

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.

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