Abstract: A method of operating an electrical power system for an aircraft. The electrical power system includes a semiconductor-based active power converter and a contactor coupled to and controllable by the semiconductor-based active power converter. The method includes, in response to a determination that there is a fault within the electrical power system, operating in a fault mode which includes: maintaining the semiconductor-based active power converter in a blocked configuration (optionally followed by maintaining the semiconductor-based active power converter in a crow-bar configuration); and subsequently causing the contactor to be opened.

Abstract: An electrical power system 10 and a method 300 of controlling an electrical power system 10 are provided. The electrical power system 10 comprises a DC:DC power converter 100 connected between a DC power source 11 and a DC electrical network 12. The DC electrical network 12 comprises at least a first zone Z1 for powering a first group of one or more electrical loads 12La-b, a second zone Z2 for powering a second group of one or more electrical loads 12Lc-d, a first controllable circuit breaker X1, and a second controllable circuit breaker X2.

Abstract: The invention concerns the damping of torsional oscillations/vibrations, particularly during electrical power generation within a gas turbine such as a civil aviation engine. The method of the invention relies on actively generating compensating oscillations in a driveline of a system to actively damp undesirable oscillations existing in the system.

Abstract: A discrete event simulation (DES) and method of model development provide affordable, accurate, pre-validated, reusable and portable models and simulations that capture the complexity, interdependencies and stochastic nature of the operations and support (O&S) of weapons systems. A model of the O&S problem is created based on a service use profile (SUP) that describes a logical structure of delivery, maintenance, deployment, testing policy, infrastructure and logistics constraints. That model is translated into a DES, preferably using a “toolkit” including common attributes for the weapons and pre-validated common blocks and sub-models that define higher level functionality. The DES calculates a time-based prediction of weapons availability, maintenance activities, and spare parts stock over a life cycle of the weapons system.

Abstract: A stationery article of manufacture for carrying one or more self-stick note pads in combination with one or more other items, such as, business cards, photo identification cards, credit cards, check books, calculators, personal digital assistants, a wireless e-mail reader, and other similar items for convenience.

Abstract: A stationery article of manufacture for carrying one or more self-stick note pads in combination with one or more other items, such as, business cards, photo identification cards, credit cards, check books, calculators, personal digital assistants, a wireless e-mail reader, and other similar items for convenience.