Abstract: A laser system and method employing stimulated Raman scattering using a main laser pulse and a delayed replica reference pulse are provided. A further aspect calculates stimulated Raman loss and stimulated Raman gain from a reflected laser light scatter collected from a fabric or paper specimen. In another aspect, a laser system receives a low energy portion of a spectrum of main and reference laser pulses with a first photodetector, receives a higher energy portion of the spectrum of the main and reference pulses with a second photodetector, and uses a controller to determine a Raman active phonon transfer of energy manifested as an increase in the reflected laser scatter in a lower energy portion of the spectrum and a decrease in a higher energy portion of the spectrum. In yet another aspect, the controller automatically determines if a hazardous particle or substance such as an explosive, is present on a specimen.

Abstract: A laser system and method employing stimulated Raman scattering using a main laser pulse and a delayed replica reference pulse are provided. A further aspect calculates stimulated Raman loss and stimulated Raman gain from a reflected laser light scatter collected from a fabric or paper specimen. In another aspect, a laser system receives a low energy portion of a spectrum of main and reference laser pulses with a first photodetector, receives a higher energy portion of the spectrum of the main and reference pulses with a second photodetector, and uses a controller to determine a Raman active phonon transfer of energy manifested as an increase in the reflected laser scatter in a lower energy portion of the spectrum and a decrease in a higher energy portion of the spectrum. In yet another aspect, the controller automatically determines if a hazardous particle or substance such as an explosive, is present on a specimen.

Abstract: A centrifugal particle separator removes particles such as dust particles from a compressed airflow prior to reaching and cooling the turbine blades of a turbine engine. A particle separator structure defines a plurality of inward-facing pockets which are separated by pocket dividers defining an airflow path having a diameter that decreases from the entrance to the exit. A centrifugal force created by the rotating centrifugal particle separator assembly causes particles to collect within the plurality of pockets and the remaining compressed air is provided to cool the turbine blades. The decreasing diameter of the airflow path forces the airflow with particles to accelerate to a rotational velocity greater than that of the rotating particle separator by conservation of momentum.

Abstract: A centrifugal particle separator (202) is provided for removing particles such as dust particles from the compressed airflow (110) prior to reaching and cooling the turbine blades (122, 124, 126) of a turbine engine (100). A particle separator structure (208) has a side facing the axis (118) about which it rotates, the side including a plurality of pocket dividers (214) defining a plurality of pockets (216), and further defining an entrance cavity (206) for receiving the compressed air (110) containing particles.