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A novel method is described for remotely interrogating bulk molecular composition of rocky materials. Laser energy heats a local area on the substrate; flux is optimized to melt and evaporate target constituents with low rates of molecular dissociation. Substrate temperature rises until an equilibrium is established between incident flux and latent phase-change energies, reaching ˜2500 K in vacuum. A blackbody signal is emitted by the heated spot, traveling outward through the evaporated material; reflective optics direct the signal into a spectrometer. Ro-vibrational absorption in the plume provides a diagnostic for identifying bulk molecular composition of the substrate. Absorption spectra are modeled for compounds with available a priori molecular cross-sections, based on laser and receiver characteristics, and target material properties. Mass ejection flux drives the plume density profile. Qualitative, species-specific spectral profiles are derived by integrating molecular cross section along a path through the plume. Simulations indicate robust absorption profiles. [ABSTRACT FROM AUTHOR]

Large bore reciprocating internal combustion (IC) engines are used in a wide variety of applications such as power generation, transportation, gas compression, mechanical drives, and mining. Each application has its own unique requirements that influence the engine design and control strategy. The system architecture and control strategy play a key role in meeting the requirements. Traditionally, control design has come in at a later stage of the development process, when the system design is almost frozen. Furthermore, transient performance requirements have not always been considered adequately at early design stages for large engines, thus limiting achievable controller performance. With rapid advances in engine modeling capability, it has now become possible to accurately simulate engine behavior in steady-states and transients. In this paper, we propose an integrated model-based approach to system design and control of reciprocating engines and outline ideas, processes, and real-world case studies for the same. Key benefits of this approach include optimized engine performance in terms of efficiency, transient response, emissions, system and cost optimization, and tools to evaluate various concepts before engine build thus leading to significant reduction in development time and cost. [ABSTRACT FROM AUTHOR]

Directed energy phased array (DEPA) systems have been proposed for applications such as beaming optical power for electrical use on remote sensors, rovers, spacecraft, and future moon bases, as well as for planetary defense against asteroids and photonic propulsion up to relativistic speeds. All such scenarios involve transmission through atmosphere and beam perturbations due to turbulence that must be quantified. Numerical beam propagation and feedback control simulations were performed using an algorithm optimized for efficient calculation of real-time beam dynamics in a Kolmogorov atmosphere. Results were used to quantify the effectiveness of the system design with different degrees of atmospheric turbulence and zenith angles, and it was found that a large aperture DEPA system placed at a high altitude site can produce a stable diffraction limited spot ( S t r e h l >0.8) on space-based targets for Fried length r 0 ≥10 c m (at 500 nm) and zenith angles up to 60 deg, depending on atmospheric conditions. We believe these results are promising for the next generation of power beaming and deep space exploration applications.