OB–stars have the highest luminosities and strongest stellar winds of all stars, which enables them to interact strongly with their surrounding ISM, thus creating bow shocks. These offer us an ideal opportunity to learn more about the ISM. They were first detected and analysed around runaway OB–stars using the IRAS allsky survey by van Buren et al. (1995). Using the geometry of such bow shocks ...

Abrasive Water Jet Machining is an unconventional machining process well known for machining hard to cut materials. The primary research focus on the process was for through cutting and a very limited literature is available on pocket milling using AWJM. The present work is an attempt to use this process for milling applications considering a set of various process parameters. Four different in...

We describe a new compact acousto-optically Q-switched diode-pumped solid-state (DPSS) intracavity frequency-tripled neodymium-doped yttrium vanadate laser capable of producing ~100 mW of 213 nm power quasi-continuous wave as 15 ns pulses at a 30 kHz repetition rate. We use this new laser in a prototype of a deep ultraviolet (UV) Raman standoff spectrometer. We use a novel high-throughput, high...

The Army is investigating several spectroscopic techniques (e.g., infrared spectroscopy) that could allow for an adaptable sensor platform. Current sensor technologies, although reasonably sized, are geared to more classical chemical threats, and the ability to expand their capabilities to a broader range of emerging threats is uncertain. Recently, photoacoustic spectroscopy (PAS), employed in ...

The ability to perform not only elementally but also isotopically sensitive detection and analysis at standoff distances is impor-tant for remote sensing applications in diverse ares, such as nuclear nonproliferation, environmental monitoring, geophysics, and planetary science. We demonstrate isotopically sensitive real-time standoff detection of uranium by the use of femtosecond filament-induc...

Recently, DRDC Valcartier has been investigating novel ground-based longwave hyperspectral imaging (HSI) remote sensing techniques. Specific projects include the development of a new ground-based sensor called MoDDIFS (Multi-Option Differential Detection and Imaging Fourier Spectrometer), which is a leading edge infrared (IR) hyperspectral imaging (HSI) sensor optimized for the standoff detecti...

The present study proposes novel micro-jet impingement heat sink with effusion holes for flow extraction. The design consists of impingement nozzles surrounded by multiple effusion holes to take away the spent fluid. A three-dimensional numerical model is used for steady, incompressible, laminar flow and conjugate heat transfer for the performance analysis of the proposed design. The computatio...

An intercept mission with nuclear explosives is the only practical mitigation option against the most probable impact threat of near-Earth objects (NEOs) with a short warning time (e.g., much less than 10 years). Although a less destructive, standoff nuclear explosion can be employed in such a last minute intercept mission, the momentum/energy transfer created by a shallow subsurface nuclear ex...