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PETN homologs

Description: High purity nitrate esters of the pentaerythritols can be successfully synthesized from correspondingly high purity reagents. The latter are not commercially available, but may be purified through molecular distillation and/or fractional crystallization from xylene. The isolated products are ultimately saponified to reagents of high purity. The nitration of high purity pentaerythritols using 97-100% nitric acid proceeds smoothly resulting in yields of the corresponding nitrate esters which are nearly quantitative. Thin layer chromatography (TLC) indicates numerous satellite impurities present in all the pentaerythritol-tetranitrate (PETN) homologs with the exception of ultrapure PETN itself. Separation and isolation of these contaminants, from a high impurity concentrate, was achieved by liquid chromatography. IR spectra of these components suggests these compounds are the various homologs and pentaerythryl ethers with a mixture of hydroxyl and nitrate functional groups.
Date: February 1, 1972
Creator: Sandoval, J. & Quinlin, W.T.
Partner: UNT Libraries Government Documents Department

Fast gas chromotography with luminol detection for measurement of nitrogen dioxide and PANs.

Description: Fast capillary gas chromatography has been coupled to a luminol-based chemiluminescence detection system for the rapid monitoring of nitrogen dioxide and peroxyacyl nitrates. A first-generation instrument was described recently (Gaffney et al., 1998). This system is capable of monitoring nitrogen dioxide and peroxyacyl nitrates (PANs; to and including the C4 species) with 1-min time resolution. This is an improvement by a factor of five over gas chromatography methods with electron capture detection. In addition, the luminol method is substantially less expensive than laser fluorescent detection or mass spectroscopic methods. Applications in aircraft-based research have been published electronically and will appear shortly in Environmental Science and Technology (Gaffney et al., 1999a). An improved version of the instrument that has been designed and built makes use of a Hammamatsu photon-counting system. Detection limits of this instrumentation are at the low tens of ppt. The range of the instrument can be adjusted by modifying sampling volumes and detection counting times. A review of past work and of recent application of the instrumentation to field measurements of nitrogen dioxide and PANs is presented. The data clearly indicate that the luminol approach can determine the target species with time resolution of less than 1 min. Examples of applications for estimation of peroxyacetyl radical concentrations and nitrate radical formation rates are also presented. This instrumentation can further be used for evaluation of surfaces for loss of nitrogen dioxide and PANs, phenomena of possible importance for sampling interfaces and chamber wall design. Our high-frequency field data clearly indicate that the ''real world'' is not well mixed and that turbulent mixing and plume-edge chemistries might play an important role in urban- and regional-scale interactions. Dynamic flow systems might be required to evaluate such effects in new-generation chamber studies.
Date: September 30, 1999
Creator: Gaffney, J. S.; Marley, N. A. & Drayton, P. J.
Partner: UNT Libraries Government Documents Department

Plasma-Catalysis During Temperature Transient Testing

Description: A combination of catalysts is used together with nonthermal plasma in simulated diesel exhaust, while the gas temperature is varied. The catalysts both store and convert pollutants. As a result, pollutant concentrations during temperature ramps are different than those at steady state conditions. The data are presented for plasma followed by BaY, alumina, and Pt catalysts in simulated exhaust. When temperature ramps from high to low, apparent NOx conversion is quite high. However, when temperature is ramped from low to high, lower apparent conversions are seen. In a typical test cycle, average NOx conversion between 100 and 400 C is 60%. Peak conversion during the down ramp is over 90%, and minimum conversion during the up ramp is 30%. The composition of the effluent gas also varies during the temperature cycle. Intermediates such as methyl nitrate and hydrogen cyanide are not present following the combination of catalysts.
Date: August 5, 2001
Creator: Hoard, John
Partner: UNT Libraries Government Documents Department

Vapor space characterization of waste Tank 241-B-103: Results from samples collected on 2/8/95

Description: This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-B-103 (referred to as Tank B-103). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, five were observed above the 5-ppbv reporting cutoff. Twenty-six organic tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv, and are reported with concentrations that are semiquantitative estimates based on internal standard response factors. Twenty-three TICs were measured in two or more SUMMA{trademark} canisters. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 66% of the total organic components in Tank BB-103. Two permanent gases, carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O), were also detected. Tank B-103 is on the Organic Watch List.
Date: October 1, 1995
Creator: Ligotke, M.W.; Pool, K.H. & Lucke, R.B.
Partner: UNT Libraries Government Documents Department

Vapor space characterization of waste Tank 241-C-107: Results from samples collected on 9/29/94

Description: This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-C-107 (referred to as Tank C-107). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for sulfur oxides (SO{sub x}) was not requested. Organic compounds were also quantitatively determined. Twenty organic tentatively identified compounds (TICs) were observed above the detection limit of (ca.) 10 ppbv, but standards for most of these were not available at the time of analysis, and the reported concentrations are semiquantitative estimates. In addition, the authors looked for the 55 TO-14 extended analytes. Of these, 3 were observed above the 5-ppbv detection limit. The 10 organic analytes with the highest estimated concentrations are listed in Summary Table 1 and account for approximately 96% of the total organic components in Tank C-107. Two permanent gases, carbon dioxide and nitrous oxide, were also detected.
Date: November 1, 1995
Creator: Pool, K.H.; Clauss, T.W. & Ligotke, M.W.
Partner: UNT Libraries Government Documents Department

Thermal properties. Period covered: October--December 1975

Description: The thermal decomposition investigation of PETN using an LX-13 type PETN was begun this quarter. Samples are being conditioned at 373, 353 and 333/sup 0/K and others will be conditioned at 393 and 383/sup 0/K. Data from five samples are reported. A series of chemical reactivity tests was made using PETN to determine if decomposition rates could be calculated from the results. The data fit a semilogarithmic plot of the gas evolved as a function of time reasonably well. The last of a series of HNAB and PETN samples was evaluated to determine if the two are compatible. These samples were conditioned at 80/sup 0/C for 26 and 25 months and showed no indication of reactivity. The investigation into methods of improving the chemical reactivity test data has continued and a source of a small variation in the instrument sensitivity was determined.
Date: January 1, 1975
Creator: Myers, L.C.
Partner: UNT Libraries Government Documents Department

Shock initiation sensitivity of PETN: A steric hindrance model

Description: In this report, shock initiation sensitivity of PETN crystals is discussed. A new molecular model for shock sensitivity in crystalline solids is proposed in terms of steric hindrance to edge dislocation motion. This model is successful in predicting the relative shock sensitivities of the four PETN orientations studied, especially at low stresses. (JL)
Date: January 1, 1991
Creator: Dick, J.J.
Partner: UNT Libraries Government Documents Department

Radial buildup to detonation in pentaerythritol tetranitrate (PETN)

Description: Purified PETN was pressed to a density of 0.95 g/cc in Lucite cylinders of 2.54-cm diameter and 0.76-cm length. These charges were initiated by means of an exploding bridgewire located in the center of one face of the pressing. The firing capacitance and inductance were held constant. The energy delivered to the explosive charge was changed by varying the condenser voltage. The radial buildup to detonation was recorded by a rotating mirror camera with the slit perpendicular to the bridgewire. Results are discussed. The conclusion is that the deflagration to detonation development is not perfectly spherical from the initiation source but more ellipsoidal with the highest rate oriented along the charge length. 3 figs., 1 tab.
Date: October 1, 1985
Creator: Dinegar, R.H.
Partner: UNT Libraries Government Documents Department

Maximum credible event determination for the surveillance powder samples and their handling containers

Description: An investigation was done to determine the maximum credible event value for samples of explosives and disassembled components up to 1.2 g when stored in conductive plastic vials as packaged and handled, stored, or transported at Mound. The test was performed at Test Firing, with photographs taken before and after the test. The standard propagation test setup was used; a vial containing 1.2 g of PETN (pentaerythritol tetranitrate) was surrounded by other like vials containing 1.2-g samples of PETN. The 1.2-g PETN pellet was then ignited by an EX-12 detonator. The test showed that there was no propagation and that the maximum credible event value for the handling tray is 1.2 g. The test also showed that when the tray is placed in a metal container the MCE value will still be 1.2 g. 9 figs.
Date: September 19, 1991
Creator: Jones, R.B. & Cogan, J.D. Jr.
Partner: UNT Libraries Government Documents Department

Shock initiation of explosive pellets at low temperature. [PETN, PBX-9407, HNS-1]

Description: Electrically-driven flyer plates have been used to initiate the high explosives PETN, PBX-9407 and HNS-1 at 194/sup 0/K and 77/sup 0/K. Electrically-exploded aluminum foils accelerated 51-..mu..m thick plastic flyer plates to impact the explosive pellets. The flyer-plate components and the explosive pellets were cooled to the desired temperature by immersing them in dry ice (194/sup 0/K) or liquid nitrogen (77/sup 0/K). Two firing systems were used. In one system a 0.6..mu..F capacitor supplies energy to a 0.635 x 0.011mm bridgefoil. In the other system a 6.0..mu..F capacitor supplies energy to a 1 x 1 x 0.011mm bridgefoil. The change in threshold current for initiation due to temperature effects is discussed.
Date: February 7, 1979
Creator: Gilman, D.S.
Partner: UNT Libraries Government Documents Department

Precursors in detonations in porous explosives

Description: Photographs of detonation waves in low-density HMX and PETN, made with an image-intensifier camera, show a brilliant band of light in front of the pressure jump. The radiation temperature is estimated to be 12,000 to 14,000/sup 0/K. The spectrum of this light is continuous. A quartz gauge shows a gradual buildup of pressure from the material producing the light. The material has little effect on the propagation of detonation. Further observations, using pellets of plastic-bonded HMX and single crystals of PETN, show that the material thrown off the free surface is transparent, with a leading edge moving at approximately 20 mm/..mu..s. Collision of this material with polymethyl methacrylate (PMMA) produces a brilliant light with a spectrum that is initially a narrow H/sub ..cap alpha../ line. Quartz gauges measure the rate of pessure buildup of this material.
Date: January 1, 1981
Creator: Spaulding, R.L. Jr.
Partner: UNT Libraries Government Documents Department

Effects of particle characteristics on performance of RR5K PETN

Description: A particle characterization of production lots of RR5K PETN has been completed. Prediction models were derived which identify those particle characteristics which influence sensitivity and performance. Those factors which have a positive influence on threshold burst current were also found to have a positive influence on transit time. The models may be useful in screening new lots of PETN prior to test firing. In general, large distributions of shapes and sizes, with the larger particles being needle-like or elongated, lead to low threshold burst currents and short transit times. The threshold burst current was also found to be inversely proportional to the temperature at which the units were test fired.
Date: June 1, 1982
Creator: Rogers, J.W. Jr. & Duncan, A.A.
Partner: UNT Libraries Government Documents Department

X-ray Photoelectron Spectroscopy study of the compatibility of the explosive PETN with candidate plastic bonding materials

Description: The compatibility of the explosive PETN with two plastic bonding materials, ethyl cellulose and a halogenated vinyl polymer (FPC 461), was determined by X-ray Photoelectron Spectroscopy (XPS). Both were found to coat the PETN crystals, and no change in chemical composition was found in the PETN or the plastic due to either the process or their mutual presence. 3 refs., 1 fig., 1 tab.
Date: January 1, 1985
Creator: Vannet, M.D.; Wang, P.S.; Moddeman, W.E. & Bowling, W.C.
Partner: UNT Libraries Government Documents Department

Compatibility of PETN with lead azide

Description: The compatibility of PETN with lead azide at elevated temperatures has been investigated. Ramped and isothermal DSC methods were used to obtain energies of activation at temperatures above the melting point of PETN. Mixtures were found to show exothermic activity at lower temperatures than pure PETN. High Pressure Liquid Chromatography was used to follow the decomposition of PETN and PETN/lead azide mixtures at temperatures below the melting point. Reaction below 120/sup 0/C appeared minimal, while at higher temperatures, both PETN and PETN/lead azide mixtures showed degradation. A PETN/lead azide sample exploded at or near the melting point of PETN.
Date: January 1, 1983
Creator: Hurd, R.; Fronabarger, J.W.; Johnson, R. & Fleming, W.
Partner: UNT Libraries Government Documents Department

Three-dimensional hydrodynamic hot-spot

Description: The basic processes in the shock initiation of heterogeneous explosives have been investigated theoretically using a model of a cube of nitromethane containing 91 cubic air holes. The interaction of a shock wave with a single air hole and a matrix of air holes in PETN, HMX, and TATB has been numerically modeled. The interaction of a shock wave with the density discontinuities, the resulting hot-spot formation and interaction, and the buildup to propagating detonation were computed using three-dimensional numerical Eulerian hydrodynamics with Arrhenius chemical reaction and accurate equations of state according to the hydrodynamic hot-spot model. The basic processes in the desensitization of a heterogeneous explosive by preshocking with a shock pressure too low to cause propagating detonation was numerically modeled. The basic differences between shock sensitive explosives such as PETN or HMX and shock insensitive explosives such as TATB or NQ may be described using the hydrodynamic hot-spot model.
Date: January 1, 1984
Creator: Mader, C.L.
Partner: UNT Libraries Government Documents Department

Crystal orientation effects in PETN explosive with 4 GPa shocks

Description: Shock initiation of detonation has been observed in PETN crystals of /l angle/110/r angle/ orientation at the low shock strength of 4.25 GPa. This result explains some observations by other workers at Los Alamos National Laboratory that were considered anomalous. Chemiluminescent emission from the shock-induced decomposition reactions has been observed using OMA spectrographs, photodiodes, and image intensifier cameras. The emission is not seen in the insensitive orientations, /l angle/100/r angle/ and /l angle/101/r angle/; these orientations can deform using the primary slip plane, (110). 4 refs.
Date: January 1, 1989
Creator: Dick, J.J.; Pettit, D.R. & Spencer, W.J.
Partner: UNT Libraries Government Documents Department

Free-expansion experiments and modeling in detonation: Chemistry and hydrodynamics on a laboratory scale

Description: Laboratory-scale (25-50 mg) detonations of PETN, RDX, HNS, and TNT have been carried out in a high-vacuum chamber, and collisionless molecular beams of the freely expanding detonation products have been analyzed as a function of time with a mass spectrometer. Concurrently, time-sequenced schlieren and shadowgraph images of the initial expansion of the product plume are recorded using a pulsed laser for illumination. These data tie the chemistry and hydrodynamics of the detonation event together. The results, interpreted with the aid of a computer model, suggest that this experiment freezes the chemical reactions of detonation by rapid adiabatic cooling and provides a continuum of samples in the molecular beam, representing the sequence of reactions in the detonating charge. With a suitable model of the expansion hydrodynamics, the hydrodynamic histories of a sequence of volume elements can be associated with their frozen chemistries. We expect experiments like this to provide a test for molecular models of detonation. 10 refs., 5 figs.
Date: January 1, 1989
Creator: Greiner, N.R. & Blais, N.
Partner: UNT Libraries Government Documents Department

Laser-driven miniature flyer plates for shock initiation of secondary explosives

Description: Miniature flyer plates (<1-mm diameter X <5-micron thick) of aluminum and other materials are accelerated by a 10-ns pulsed Nd:YAG laser to velocities >5 km/s. Velocity profiles are recorded by velocity interferometry (VISAR) techniques and impact planarity by electronic streak photography. Techniques for improving energy coupling from laser to flyer plate will be discussed. Flyer plate performance parameters will be compared with material properties. The P/sup n/t criteria for shock initiation of explosives will be compared for various flyer materials, pressure, and pulse duration. Performance of secondary explosives (PETN, HNS, HMX, various PBX, others) will be reported. These data will detail the experimental effect of t (in P/sup n/t) approaching values of a few nanoseconds. 9 refs., 5 figs.
Date: January 1, 1989
Creator: Paisley, D.L.
Partner: UNT Libraries Government Documents Department

Time-resolved spectroscopic studies of detonating heterogeneous explosives. [HMX and HNS]

Description: Emission spectroscopy and pulsed-laser-excited Raman scattering methods have been applied to the study of detonating heterogeneous explosives, including PETN, HMX and HNS. Time-resolved spectra of emission from detonating HNS show the evolution of features due to electronically-excited radical species. For HNS, the CN(B-X) system near 388 nm has been studied at a wavelength resolution of 0.5 A. Boltzmann vibrational temperatures have been calculated by comparing the experimental data with computer-simulated spectra. These temperatures are consistent with the expected trend of detonation temperature as a function of charge density. Using 532-nm laser excitation, single-pulse Raman scattering measurements have been made at the free surface of detonating HMX and PETN samples. Monotonic attenuation of Raman scattering intensity over a 100-ns interval is observed after detonation front arrival at the free surface. Depletion of the Raman signal occurs prior to significant loss of the scattered laser light. The significance of the Raman measurements as a possible probe of reaction zone length in detonating explosives is discussed. 21 refs., 11 figs.
Date: January 1, 1985
Creator: Trott, W.M. & Renlund, A.M.
Partner: UNT Libraries Government Documents Department