High performance ammonium nitrate propellant

A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine

A modified Next Reaction Method for simulating chemical systems with time dependent propensities and delays

Chemical reaction systems with a low to moderate number of molecules are typically modeled as discrete jump Markov processes. These systems are oftentimes simulated with methods that produce statistically exact sample paths such as the Gillespie Algorithm or the Next Reaction Method. In this paper we make explicit use of the fact that the initiation times of the reactions can be represented as the firing times of independent, unit rate Poisson processes with internal times given by integrated propensity functions. Using this representation we derive a modified Next Reaction Method and, in a way that achieves efficiency over existing approaches for exact simulation, extend it to systems with time dependent propensities as well as to systems with delays.Comment: 25 pages, 1 figure. Some minor changes made to add clarit

Incorporating postleap checks in tau-leaping

By explicitly representing the reaction times of discrete chemical systems as the firing times of independent, unit rate Poisson processes, we develop a new adaptive tau-leaping procedure. The procedure developed is novel in that accuracy is guaranteed by performing postleap checks. Because the representation we use separates the randomness of the model from the state of the system, we are able to perform the postleap checks in such a way that the statistics of the sample paths generated will not be biased by the rejections of leaps. Further, since any leap condition is ensured with a probability of one, the simulation method naturally avoids negative population valuesComment: Final version. Minor change

n-Heptane hydroconversion over sulfated-zirconia-supported molybdenum carbide catalysts

Tertiary Education Trust Fund (TETFUND) NigeriaPeer reviewedPublisher PD

Parametric design study - Recuperator development program, solar Brayton cycle system

Heat exchangers for recuperator in closed Brayton cycle space power system using solar energy and argo

Measuring the U.S. Health Care System: A Cross-National Comparison

Compares U.S. healthcare data including hospital beds and physicians, hospital and physician visits, healthcare spending, and high-tech procedures per capita, as well as life expectancy with those of twenty-nine other industrialized countries

Recuperator development program, solar brayton cycle system progress report, 19 jul. - 19 aug. 1964

Heat exchanger and energy recuperator for closed Brayton cycle syste

A bounded jump for the bounded Turing degrees

We define the bounded jump of A by A^b = {x | Exists i <= x [phi_i (x) converges and Phi_x^[A|phi_i(x)](x) converges} and let A^[nb] denote the n-th bounded jump. We demonstrate several properties of the bounded jump, including that it is strictly increasing and order preserving on the bounded Turing (bT) degrees (also known as the weak truth-table degrees). We show that the bounded jump is related to the Ershov hierarchy. Indeed, for n > 1 we have X <=_[bT] 0^[nb] iff X is omega^n-c.e. iff X <=_1 0^[nb], extending the classical result that X <=_[bT] 0' iff X is omega-c.e. Finally, we prove that the analogue of Shoenfield inversion holds for the bounded jump on the bounded Turing degrees. That is, for every X such that 0^b <=_[bT] X <=_[bT] 0^[2b], there is a Y <=_[bT] 0^b such that Y^b =_[bT] X.Comment: 22 pages. Minor changes for publicatio