Cryocycling of Energetic Materials: Final Report

The Cryocycling of Energetic Materials Project was executed in the period FY`94-96 as a Life Cycle Engineering activity in the Memorandum of Understanding (MOU) on advanced conventional munitions. This MOU is an agreement between the Departments of Energy and Defense (Office of Munitions) that facilitates the development of technologies of mutual interest to the two Departments. The cryocycling process is a safe, environmentally friendly, and cost effective means of rubblizing bulk energetic materials so that they can be easily reused in a variety of new products. For this reason, cryocycling of excess solid energetic materials is one of the recycle/reuse strategies under study for demilitarized munitions in the Departments of Energy and Defense. These strategies seek to minimize the environmental damage associated with disposal of decommissioned energetic materials. In addition, they encourage technologies that can be used to derive economic benefit from reuse/reapplication of materials that would otherwise be treated as hazardous wastes. 45 refs., 38 figs., 7 tabs

Hydrogen storage for vehicular applications: Technology status and key development areas

The state-of-the-art of hydrogen storage technology is reviewed, including gaseous, liquid, hydride, surface adsorbed media, glass microsphere, chemical reaction, and liquid chemical technologies. The review of each technology includes a discussion of advantages, disadvantages, likelihood of success, and key research and development activities. A preferred technological path for the development of effective near-term hydrogen storage includes both cur-rent DOT qualified and advanced compressed storage for down-sized highly efficient but moderate range vehicles, and liquid storage for fleet vehicle applications. Adsorbate media are also suitable for fleet applications but not for intermittent uses. Volume-optimized transition metal hydride beds are also viable for short range applications. Long-term development of coated nanoparticulate or metal matrix high conductivity magnesium alloy, is recommended. In addition, a room temperature adsorbate medium should be developed to avoid cryogenic storage requirements. Chemical storage and oxidative schemes present serious obstacles which must be addressed for these technologies to have a future role

Reentry vehicle response to impacts with rigid targets

Numerical analyses were performed to determine the effect of specific impacts on a reentry vehicle. The objective of these analyses was to determine those combinations of environment levels and failure pathways which have some potential of leading to exposure of internal regions of a reentry vehicle. The methodologies employed in the study utilized existing structural finite element modeling techniques. The results of these analyses have been enumerated for rigid rail and probe impacts to specific locations on the reentry vehicle. Excellent agreement was obtained between the analyses and applicable full scale tests

Processing solid propellants for recycling

Rapid evolution in the structure of military forces worldwide is resulting in the retirement of numerous weapon systems. Many of these systems include rocket motors containing highly energetic propellants based on hazardous nitrocellulose/nitroglycerin (NC/NG) mixtures. Even as the surplus quantities of such material increases, however, current disposal methods -- principally open burning and open detonation (OB/OD) -- are coming under close scrutiny from environmental regulators. Environmentally conscious alternatives to disposal of propellant and explosives are thus receiving renewed interest. Recycle and reuse alternatives to OB/OD appear particularly attractive because some of the energetic materials in the inventories of surplus weapon systems represent potentially valuable resources to the commercial explosives and chemical industries. The ability to reclaim such resources is therefore likely to be a key requirement of any successful technology of the future in rocket motor demilitarization. This document consists of view graphs from the poster session

Fundamentals of metal fatigue analysis

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Effect of AT1 receptor blockade on endothelial function in essential hypertension

Background: Angiotensin II adversely affects endothelial function and NO availability. We analyzed the effect of AT1 receptor blockade on endothelium-dependent vasodilation and basal nitric oxide (NO) production and release in hypertensive patients. <p></p> Methods and results: Sixty patients (53 ± 10 years) with essential hypertension were randomized to 6 weeks of double-blind therapy with either valsartan (80 mg), hydrochlorothiazide (HCTZ) (25 mg), or placebo once daily. Basal NO production and release was assessed by measuring forearm blood flow (FBF) in response to intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA), and endothelium-dependent vasodilation by measuring FBF in response to intra-arterial administration of acetylcholine, respectively. Intra-arterial infusion of noradrenaline and sodium nitroprusside was used to assess endothelium-independent changes in FBF. Blood pressure (BP) similarly decreased with active treatments (P < .001). After valsartan treatment, the decrease of FBF in response to L-NMMA was augmented (4 μmol/min L-NMMA, −1.3 ± 1.2 after v −0.5 ± 1.1 mL/min/100 mL before therapy, P < .02; 8 μmol/min L-NMMA: −1.7 ± 1.3 after v −1.1 ± 1.2 mL/min 100 mL before therapy, P < .05). No improvement was found after placebo or HCTZ treatment. Changes in L-NMMA-induced decrease of FBF with valsartan treatment were not related to BP changes. Neither drug substantially modified the response of FBF induced by intra-arterial infusion of acetylcholine, noradrenaline, and sodium nitroprusside. <p></p> Conclusions: The AT1 receptor blockade with valsartan improved basal NO production and release. The effect seems to be BP independent, as BP reduction with HCTZ failed to increase NO availability

Fiscal Year 1994

The Cryocycling of Energetic Materials Project is sponsored by the Memorandum of Understanding (MOU) on advanced munition technologies. This MOU is an agreement between the Department of Energy and the Department of Defense (Office of Munitions) that facilitates the development of technologies of mutual interest to the two Departments. The cryocycling project is one of several that focus on demilitarization aspects of conventional weapons and weapon systems. During FY94 the project pursued the development of analytical and numerical models that can be used to describe and optimize the cryocycling process for preparing energetic materials for recycle and reuse. In addition, the demilitarization stockpile of the Department of Defense was analyzed to identify candidate munitions for the process, and pilot scale cryocycling operations were begun at an industrial contractor. When a material is cryocycled, it is repeatedly subjected to cycles of rapid cooling in a liquid nitrogen bath at 77 K followed by warming to ambient temperature. In laboratory and pilot scale demonstrations, the authors have shown that cryocycling can dramatically reduce the size of a variety of propellant grains and a number of cast and plastic bonded explosives