Uniform Substitution for Differential Game Logic

This paper presents a uniform substitution calculus for differential game logic (dGL). Church's uniform substitutions substitute a term or formula for a function or predicate symbol everywhere. After generalizing them to differential game logic and allowing for the substitution of hybrid games for game symbols, uniform substitutions make it possible to only use axioms instead of axiom schemata, thereby substantially simplifying implementations. Instead of subtle schema variables and soundness-critical side conditions on the occurrence patterns of logical variables to restrict infinitely many axiom schema instances to sound ones, the resulting axiomatization adopts only a finite number of ordinary dGL formulas as axioms, which uniform substitutions instantiate soundly. This paper proves soundness and completeness of uniform substitutions for the monotone modal logic dGL. The resulting axiomatization admits a straightforward modular implementation of dGL in theorem provers

The U.S. Automotive Industry: National and State Trends in Manufacturing Employment

[Excerpt] The U.S. motor vehicle manufacturing industry\u27 employs 880,000 workers, or approximately 6.6% of the U.S. manufacturing workforce, including those who work in the large motor vehicle parts manufacturing sector, as well as those who assemble motor vehicles. Since the beginning of the decade, the nation\u27s automotive manufacturing sector has eliminated more than 435,000 automotive manufacturing jobs (or an amount equal to about 3.3% of all manufacturing jobs in 2008). The employment level first dipped below one million in 2007 and fell to 880,000 workers last year. With the restructuring and bankruptcy of Chrysler and General Motors, and the ongoing recession in the auto sector, employment in the nation\u27s automotive manufacturing industry will most likely shrink in 2009 and 2010 as additional assembly, powertrain, and auto parts plants close. This report provides an analysis of automotive manufacturing employment, with a focus on national and state trends. The 111th Congress continues to be heavily engaged in oversight and legislative proposals in response to the unprecedented crisis of the domestic motor vehicle manufacturing industry. The Detroit-based automotive manufacturers (General Motors, Ford, and Chrysler) have suffered a series of setbacks in recent years with their share of the domestic market dropping from 64.5% in 2001 to 47.5% in 2008. As a consequence, the traditional auto states of Michigan, Indiana, and Ohio have been—and will continue to be—heavily impacted by the changes taking place in the automotive sector. Together, there are now 152,000 fewer automotive manufacturing jobs in these three states than there were five years ago. Recent automotive sales and production data indicate the enormous changes taking place in today\u27s motor vehicle manufacturing sector. For instance, automotive sales fell to 13.2 million units in 2008, down by 18% from 2007, and forecasts indicate U.S. consumers are expected to purchase fewer than 10 million cars and light trucks in 2009. There has also been a loss of market share by the Detroit 3 producers which has created gains for foreign-owned domestic manufacturers and imports. Some recent Detroit 3 automotive manufacturing employment losses are partially offset by new investments by foreign-owned manufacturers in the United States as they have open, or will open, new plants in states like Indiana, Georgia, and Tennessee. Many Members of Congress, and especially those members from the traditional auto belt states of Michigan, Indiana, and Ohio, have expressed their concerns about lost jobs in the automotive manufacturing sector. With the sale of GM assets to the U.S. government and Chrysler assets to Fiat, two new companies have emerged that will be substantially smaller than the companies that went into bankruptcy. As a consequence, the total level of motor vehicle manufacturing employment will be reduced, especially in locales where facilities have closed. The most recent automotive manufacturing employment data indicate that 42% of all persons in the industry work in one of the three traditional auto belt states, each of which at present employs more than 100,000 persons in the industry. Michigan alone has accounted for 40% of the net job loss in the industry since 2003. Losses in Ohio and Indiana have been less severe, offset somewhat by foreign investment. Alabama, with fewer total automotive manufacturing employees, has been the big job gainer, adding over 12,000 auto manufacturing jobs since 2003. Texas, now the eighth largest state by automotive employment, gained 5,200 jobs between 2003 and 2008. Auto industry states in the South including Kentucky, South Carolina, and Tennessee have lost jobs in recent years, but far fewer than in the traditional auto belt states

Entrainment characteristics of unsteady subsonic jets

The effectiveness of jet unsteadiness in enhancing flow entrainment was assessed. It was conducted that entrainment depends on the type and amount of jet unsteadiness. Apparently, the mere introduction of jet unsteadiness by small sinusoidal flow angle variations is insufficient to enhance entrainment but, it should be noted that the results were obtained at measuring stations which are all many nozzle widths downstream of the jet nozzle. Thus, no fully conclusive statement can be made at this time about the entrainment close to the nozzle. The high entrainment of the fluidically oscillated jet was caused by the high-frequency content of this square wave type of oscillation but more detailed measurements are clearly needed, in particular for the fluidically oscillated and the pulsed jets. Practical ejector application requires the proper trade-off between entrainment and primary nozzle thrust efficiency

An Axiomatic Approach to Liveness for Differential Equations

This paper presents an approach for deductive liveness verification for ordinary differential equations (ODEs) with differential dynamic logic. Numerous subtleties complicate the generalization of well-known discrete liveness verification techniques, such as loop variants, to the continuous setting. For example, ODE solutions may blow up in finite time or their progress towards the goal may converge to zero. Our approach handles these subtleties by successively refining ODE liveness properties using ODE invariance properties which have a well-understood deductive proof theory. This approach is widely applicable: we survey several liveness arguments in the literature and derive them all as special instances of our axiomatic refinement approach. We also correct several soundness errors in the surveyed arguments, which further highlights the subtlety of ODE liveness reasoning and the utility of our deductive approach. The library of common refinement steps identified through our approach enables both the sound development and justification of new ODE liveness proof rules from our axioms.Comment: FM 2019: 23rd International Symposium on Formal Methods, Porto, Portugal, October 9-11, 201

A general method for unsteady stagnation region heat transfer and results for model turbine flows

Recent experiments suggest that the heat-transfer characteristics of stator blades are influenced by the frequency of passing of upstream rotor blades. The calculation of these effects requires that the movement of the stagnation point with variations in freestream velocity is properly represented together with the possible effects of turbulence characteristics on the thin leading-edge boundary layer. A procedure to permit the achievement of these purposes is described for laminar flows in this paper together with results of its application to two model problems which demonstrate its abilities and quantify the influence of wake characteristics on fluid-dynamic and heat-transfer properties of the flow and their effects on surface heat transfer

Dynamic airfoil stall investigations

Experimental and computational investigations of the dynamic stall phenomenon continue to attract the attention of various research groups in the major aeronautical research laboratories. There are two reasons for this continued research interest. First, the occurrence of dynamic stall on the retreating blade of helicopters imposes a severe performance limitation and thus suggests to search for ways to delay the onset of dynamic stall. Second, the lift enhancement prior to dynamic stall presents an opportunity to achieve enhanced maneuverability of fighter aircraft. A description of the major parameters affecting dynamic stall and lift and an evaluation of research efforts prior to 1988 has been given by Carr. In this paper the authors' recent progress in the development of experimental and computational methods to analyze the dynamic stall phenomena occurring on NACA 0112 airfoils is reviewed. First, the major experimental and computational approaches and results are summarized. This is followed by an assessment of our results and an outlook toward the future

The Aims of the Criminal Law

Cu2ZnSnS4(CZTS) is an interesting material for sustainable photovoltaics, but efficiencies are limitedby the low open-circuit voltage. A possible cause of this is disorder among the Cu and Zn cations, aphenomenon which is difficult to detect by standard techniques. We show that this issue can beovercome using near-resonant Raman scattering, which lets us estimate a critical temperature of 533±10 K for the transition between ordered and disordered CZTS. These findings have deepsignificance for the synthesis of high-quality material, and pave the way for quantitative investigationof the impact of disorder on the performance of CZTS-based solar cells.kestCa

Transparent yttrium hydride thin films prepared by reactive sputtering

Metal hydrides have earlier been suggested for utilization in solar cells. With this as a motivation we have prepared thin films of yttrium hydride by reactive magnetron sputter deposition. The resulting films are metallic for low partial pressure of hydrogen during the deposition, and black or yellow-transparent for higher partial pressure of hydrogen. Both metallic and semiconducting transparent YHx films have been prepared directly in-situ without the need of capping layers and post-deposition hydrogenation. Optically the films are similar to what is found for YHx films prepared by other techniques, but the crystal structure of the transparent films differ from the well-known YH3 phase, as they have an fcc lattice instead of hcp

Membrane distillation - A technology for resource recovery in communal waste water treatment

In the past years lots of research in the area of membrane distillation (MD) has been conducted, especially in the fields of desalination. Nevertheless there are many new fields with possible applications of MD. With this paper the role of MD in communal wastewater treatment is presented. During the aerobic sewage treatment of a conventional Waste Water Treatment Plant (WWTP) resources such as nitrogen and carbon are destroyed. For this reason membrane distillation was applied for the separation of ammonia. An overall system integration concept could direct the WWTP from being a consumer into a producer – cleaning water while providing resources in form of valuable products. Along with population growth the demand for water, resources and energy will be drastically increased within the next decades. In this study the general stability of a poly tetra fluor ethylene (PTFE) membrane was tested by conducting liquid entry pressure (LEP) tests such as contact angle (CA) measurements with membranes that have been exposed to the waste water before. A spiral wound module was custom-made and a pilot plant (20`- Container, (6058 x 2438 mm)) was designed and constructed. Tests were carried out on-site of a waste water treatment plant for a few month of period. The suitability of the MD configuration for ammonia recovery was proven. Different test- and cleaning conditions were studied in order to evaluate the best-achievable separation factors. The dissociation equilibrium of ammonia-ammonium was taken into account, in terms of temperature and pH value, when conducting the ammonia separation experiments. The paper will present results from field tests at the waste water treatment plant. In the scope of this paper a concept for the integration of the membrane distillation facility into the WWTP will be presented and the potential for the integration of waste heat or solar thermal energy will be pointed out. An essential part is also the calculation of the economic feasibility of this new technology. The result will include detailed knowledge about the operation parameters such as flow rates, temperatures, energy consumption etc

“It Keeps Going and Going and Going”: The Expansion of False Advertising Litigation Under the Lanham Act

To improve the conduction band alignment and explore the influence of the buffer-absorber interface, we here investigate an alternative buffer for Cu2ZnSnS4 (CZTS) solar cells. The Zn(O, S) system was chosen since the optimum conduction band alignment with CZTS is predicted to be achievable, by varying oxygen to sulfur ratio. Several sulfur to oxygen ratios were evaluated to find an appropriate conduction band offset. There is a clear trend in open-circuit voltage Voc, with the highest values for the most sulfur rich buffer, before going to the blocking ZnS, whereas the fill factor peaks at a lower S content. The best alternative buffer cell in this series had an efficiency of 4.6% and the best CdS reference gave 7.3%. Extrapolating Voc values to 0 K gave activation energies well below the expected bandgap of 1.5 eV for CZTS, which indicate that recombination at the interface is dominating. However, it is clear that the values are affected by the change of buffer composition and that increasing sulfur content of the Zn(O, S) increases the activation energy for recombination. A series with varying CdS buffer thickness showed the expected behavior for short wavelengths in quantum efficiency measurements but the final variation in efficiency was small