The concept of plasma deflagration is investigated theoretically and experimentally. Deflagration is a heating process which adds energy to a flowing stream under expansion. The equations governing the process are the same as the detonation “snowplough” process; therefore, deflagration is nothing more than the second solution of the set of conservation equations.The deflagration process is thoroughly studied in the field of chemical combustion. An analogy between combustion and magnetized plasma is made, and the second law of thermodynamics is invoked in the discussion on the limits of the existence of deflagration solutions. The deflagration process that occurs in a gaseous discharge can accelerate particles to very high velocities at relatively low thermal energy. The deflagration discharge wave always propagates towards the high gas pressure and the high magnetic field region. The wave can be made stationary by injecting neutral gas into the wave. The discharge zone is thick, which reduces the local current density with a given total current and the erosion of electrodes can thus be reduced.A coaxial plasma gun has been designed, based on the deflagration principle, which demonstrates the features predicted by the deflagration hypothesis. The energy of the plasma stream thus produced exceeds 10 keV (> 108 cm/sec with D2).The discharge wave is found to be thick and the wave is quasi-stationary inside the gun barrel. Besides the high velocity capabilities, the gun can focus the plasma to a very small area. This provides a unique opportunity to perform plasma injection experiments with strong magnetic fields (> 100 kG).

Conceptual DT and DD fusion reactors are discussed based on magnetic confinement with the high-plasma-density Z-pinch. The reactor concepts have no “first wall”, the fusion neutrons and plasma energy being absorbed directly into a surrounding lithium vortex blanket. Efficient systems with low re-circulated power are projected, based on a flow-through pinch cycle for which overall Q values can approach 10. The conceptual reactors are characterized by simplicity, small minimum size (100 MW(e)) and by the potential for minimal radioactivity hazards.

No abstract

This paper describes our Align-andDifferentiate approach to the SemEval 2015 Task 2 competition for English Semantic Textual Similarity (STS) systems. Our submission achieved the top place on two of the five evaluation datasets. Our team placed 3rd among 28 participating teams, and our three runs ranked 4th, 6th and 7th among the 73 runs submitted by the 28 teams. Our approach improves upon the UMBC PairingWords system by semantically differentiating distributionally similar terms. This novel addition improves results by 2.5 points on the Pearson correlation measure.

No abstract

The Cheng Cycle gas turbine has enjoyed its 25th anniversary since its conception. More than 100 sites around the world including the United States, Japan, Australia, Italy, Germany, and the Netherlands have used the Cheng Cycle. A chronology will be presented in this paper which will highlight the steps taken to develop the fully automated, load following power and cogeneration system. The Cheng cycle operates with a steam to air ratio trajectory that has its highest “peak efficiency” at the onset of a turbine’s operation. The peak efficiency point was coined as the Cheng point by Dr. Urbach [ref.1] of the US Navy’s David Taylor Research Center. Many thermodynamic and professional textbooks refer to the original Dual Fluid Cycle as the Cheng Cycle. Besides the high efficiency feature, the Cheng Cycle is mechanically simple and flexible in operation. It can put power on line faster than a combined cycle, and it has extremely clean emissions at low cost. The future performance of the Advanced Cheng Cycle will also be projected.

No abstract

This paper identifies distinct features of the Cheng Cycle as compared to the steam injected gas turbine, STIG. Development started on the Cheng Cycle in 1974. After eight years of research and testing, the Cheng Cycle was commercialized in 1982. The commercial opportunity came by winning one of the State of California’s Energy Commission sponsored bids at the San Jose State University campus. The first Cheng Cycle power plant was built around the Allison 501KB gas turbine. The project was won on the merit of excellent thermal efficiency with maximum flexibility. It is also the most economical system because it can follow fluctuating electrical and steam loads independently. Financing, licensing and all appropriate permits were completed within one year. It took less than a year to construct and was on line by the end of 1984. Immediately, several distinct features were noticed: (1) the Cheng Cycle boosts power by 70% and efficiency by 40% over the simple cycle, (2) it can follow the electric and steam loads independently, (3) it demonstrated low emission and established 25 ppm NOx as BACT for the San Francisco Bay Area Air Quality District. In 1987, GE introduced their Steam Injected Gas Turbine, STIG, using the LM 2500 and LM 5000, and in the 1990’s GE also introduced the LM1600 version of STIG. The high pressure ratio of those engines resulted in low exhaust temperature. That is not efficient enough to power a steam cycle. Unfortunately, STIG confused some users into thinking that every steam injected gas turbine was a Cheng Cycle. STIG uses the traditional constant pressure waste heat boiler technology. Operation is limited to near full load because low exhaust temperature at partial load would cause dysfunctional heat imbalance in the heat recovery steam generator (HRSG). The Cheng Cycle, in comparison, adopted a variable pressure HRSG so its operating range extends from idle to full load. This variable pressure HRSG allows full heat recovery, whereas STIG has to limit its operating range to maintain heat transfer balance. This unique HRSG design means that the Cheng Cycle is a thermal feedback cycle. As in any feedback system it could oscillate, in this case the oscillations are between fuel-flow and steam-flow. The Cheng Cycle utilizes digital control technology to the system. The integrated system provides the user with smooth operation and rapid start-up and load change capability.