Inductive Pulse Forming Network for High-Current, High-Power Applications

PatentAn inductive pulse forming network stores electrical energy delivered from an outside prime power supply in the electric field of a low-voltage, high-energy density network capacitor. Through timed actuation of a series of one or more switches, the energy stored in the electric field of the network capacitor is subsequently converted to electrical energy stored in the magnetic field of a network inductor. The energy stored in the network inductor supplies high-current, high-power electrical energy to drive an electromagnetic launcher such as a railgun

Demonstration Of The Rotordynamic Effects Of Centrifugal Liquid Separation And Gas Compression In An Oil-Free Integrated Motor-Compressor

Lecturepg. 72-78The application of oil-free-integrated motor-compressors has become increasingly popular in recent years. One of the significant features of this class of machinery is compactness, providing space-savings compared to traditional-oil-lubricated compressors with associated gearboxes and lubrication systems. The integration of a turbo separator with such a compressor has resulted in the creation of a new class of turbomachinery promising even greater system compactness. This new machine type provides further size reduction benefits through the elimination of large static separation vessels often required on traditional compressor trains. A compressor manufacturer has successfully developed a centrifugal compressor with integrated turbo separator from design, development, and prototype testing on a demonstration rig through to manufacture, testing, and shipment of a production unit. This paper focuses on the details and results of the testing performed at the manufacturer’s factory that confirmed the soundness and acceptability of the design. Rigorous testing of the demonstration rig has confirmed acceptable rotordynamic performance including stable operation over a wide range of operating pressures and liquid injection rates. The rotordynamic performance of this machinery type has been demonstrated to be virtually insensitive to liquid injection

An examination of the aerodynamic moment on rotor blade tips using flight test data and analysis

The analysis CAMRAD/JA is used to model two aircraft, a Puma with a swept-tip blade and a UH-60A Black Hawk. The accuracy of the analysis in predicting the torsion loads is assessed by comparing the predicted loads with measurements from flight tests. The influence of assumptions in the analytical model is examined by varying model parameters and comparing the predicted results to baseline values for the torsion loads. Flight test data from a research Puma are used to identify the source of torsion loads. These data indicate that the aerodynamic section moment in the region of the blade tip dominates torsion loading in high-speed flight. Both the aerodynamic section moment at the blade tip and the pitch-link loads are characterized by large positive (nose-up) moments in the first quadrant with rapid reversal of load so that the moment is negative in the second quadrant. Both the character and magnitude of this loading are missed by the CAMRAD/JA analysis

Buried fiber optic intrusion sensor

A distributed fiber optic intrusion sensor capable of detecting intruders from the pressure of their weight on the earth's surface was investigated in the laboratory and in field tests. The presence of an intruder above or in proximity to the buried sensor induces a phase shift in light propagating along the fiber which allows for the detection and localization of intrusions. Through the use of an ultra-stable erbium-doped fiber laser and phase sensitive optical time domain reflectometry, disturbances were monitored in long (several km) lengths of optical fiber. Narrow linewidth and low frequency drift in the laser were achieved through a combination of optical feedback and insulation of the laser cavity against environmental effects. The frequency drift of the laser, characterized using an all-fiber Mach Zehnder interferometer, was found to be less than 1 MHz/min, as required for operation of the intrusion detection system. Intrusions were simulated in a laboratory setting using a piezoelectric transducer to produce a controllable optical phase shift at the 2 km point of a 12 km path length. Interrogation of the distributed sensor was accomplished by repetitively gating light pulses from the stable laser into the sensing fiber. By monitoring the Rayleigh backscattered light with a photodetector and comparing traces with and without an induced phase shift, the phase disturbances were detected and located. Once the feasibility of such a sensor was proven in the laboratory, the experimental set up was transferred to Texas A&M's Riverside Campus. At the test site, approximately 40 meters of fiber optic cable were buried in a triangle perimeter and then spliced into the 12 km path length which was housed inside the test facility. Field tests were conducted producing results comparable to those found in the laboratory. Intrusions over this buried fiber were detectable on the φ-OTDR trace and could be localized to the intrusion point. This type of sensor has the potential benefits of heightened sensitivity, covertness, and greatly reduced cost over the conventional seismic, acoustic, infrared, magnetic, and fiber optic sensors for monitoring long (multi-km) perimeters

UAS Literary & Arts Journal

Proof copy provided by Tidal Echoes.The 2016 edition of Tidal Echoes presents an annual showcase of writers and artists who share one thing in common: a life surrounded by the rainforests and waterways of Southeast Alaska.a heart is a heavy burden -- Editor’s Note -- Acknowledgements -- Always a Pause -- Untitled -- Mishima Teabowls -- Mint Tea and Red Wine -- The Dry Winter Scent of Prairies -- Northern Sunrise -- Musical Theory in a Falling Tree -- Jumbo Lookout -- The Shape of an Echo -- Wonderwall -- It’s Difficult [excerpt from the poem “Marissa”] -- Yéil x’us.eetí Raven Footprints -- táakw winter -- King Fisher -- Bear -- A Dandelion by its own Name -- Migrations -- Untitled -- They Named Her Driftwood -- Kissing in the Rain -- Waltz of the Flowers: Anna and Company -- Sun Catcher -- Porcelain Curtains -- The River -- Kathleen Lake -- A Living Tapestry -- Red Cedar Tlingit Haida Weave -- Skinned -- Survivor -- Auke Lake Lights -- Aurora Chasers -- Emma Afloat -- I Can’t Sleep -- The Ghost I’m Left With -- Framed Memories -- Tequila, Sweat, and Prayers -- The Alchemical Marriage -- A New New Hope -- each dream practice -- Clouds -- Seasons Change and the Waters Run On -- John Muir -- Salmon Speaks -- A Place That Holds Names -- Untitled -- Salmon Spirit Chest, Connected (box) -- The Language of Weaving: Featured Artist Dr. Teri Rofkar -- Nome, Alaska -- Drained -- I’m From -- Srevlla—The state of things where the spring snow is so soft that one sinks into it. -- Reflections -- Txamsem -- Post-Glacial Rebound -- Dressed in Garlands -- Learning the Dance -- Shamrocks -- When You See Me -- Water Spirit -- To Speak for Restraint, for Wildness, for Beauty: Featured Writer Aleria Jensen -- Young Eagle -- Untitled (detail) -- Baula -- Airport Dike Trail Evening -- Ninja Meatballs -- Untitled -- In the Wild Without Child: One Mother’s Invitation to Self -- Whale Tail Vista -- Questions for Anemones -- Yellow Cedarbark Wool on Starfish Pot -- Gleaming Orange and Pissed -- Through the Sky She Comes -- Love for the Honeybee -- The Last Speaker -- Juneau Fireweed -- Judy Plays the Tuba -- Illuminated Juneau -- Airport Dike Trail Moonlight -- Escape -- A Wooden Mother -- Black and Whites -- an excuse for staying indoors (a working title for a work in progress) -- Insecurities -- Lake Farm -- Yew Bear -- Rupture -- Mendenhall Glacier -- The Rookery -- Transient -- Laminaria -- Untitled -- Querencia -- Hoard -- Untitled -- Small Birds Sign -- Selfie at Two -- Entropy -- Goodbye -- Sitka Bridge -- My Remedy -- S1 -- Delta Symbols Static -- Falling -- Breathe Deeply -- Drum, drum away -- Eaglefest Dancer -- Wasichana -- Writer & Artist Biographie

How the structure of the large subunit controls function in an oxygen-tolerant [NiFe]-hydrogenase

Salmonella enterica is an opportunistic pathogen that produces a [NiFe]-hydrogenase under aerobic conditions. In the present study, genetic engineering approaches were used to facilitate isolation of this enzyme, termed Hyd-5. The crystal structure was determined to a resolution of 3.2 Å and the hydro-genase was observed to comprise associated large and small subunits. The structure indicated that His(229) from the large subunit was close to the proximal [4Fe–3S] cluster in the small subunit. In addition, His(229) was observed to lie close to a buried glutamic acid (Glu(73)), which is conserved in oxygen-tolerant hydrogenases. His(229) and Glu(73) of the Hyd-5 large subunit were found to be important in both hydrogen oxidation activity and the oxygen-tolerance mechanism. Substitution of His(229) or Glu(73) with alanine led to a loss in the ability of Hyd-5 to oxidize hydrogen in air. Furthermore, the H229A variant was found to have lost the overpotential requirement for activity that is always observed with oxygen-tolerant [NiFe]-hydrogenases. It is possible that His(229) has a role in stabilizing the super-oxidized form of the proximal cluster in the presence of oxygen, and it is proposed that Glu(73)could play a supporting role in fine-tuning the chemistry of His(229) to enable this function