Experimental Determination of E−k Relationship in Electron Tunneling

We report here measurements of electron tunneling through thin AlN films in which the imaginary component of the propagation vector in the forbidden band has been determined as a function of energy from the dependence of the tunneling current upon insulator thickness. The relationship so derived agrees well with Franz's empirical relationship for a material with the 4.2-eV forbidden-band energy of AlN. These results allow the prediction of voltage-current characteristics over the entire range of experimental variables with no arbitrary adjustable parameters, and also subject to several internal self-consistency checks. In each case complete consistency is observed, To the authors' knowledge, this represents the first unambiguous demonstration of such consistency in thin-film tunneling

Voltage Dependence of Barrier Height in AIN Tunnel Junctions

We report measurements of barrier heights on AI-AIN-Mg thin-film structures as a function of applied voltage and insulator thickness. These results are in disagreement with currently accepted theories based upon image potential and/or field penetration of the electrodes

Barrier Energies in MIM Structures from Photoresponse: Effect of Scattering in the Insulating Film

Scattering of electrons photoexcited into the insulator conduction band prevents photoresponse from following the Fowler relation in MIM structures. However, barrier energies can be obtained without specific knowledge of the scattering process either by measuring the threshold for photo response directly, or by applying sufficiently large voltages across the insulator

Testing of Two-Speed Transmission Configurations for Use in Rotorcraft

Large civil tiltrotors have been identified to replace regional airliners over medium ranges to alleviate next-generation air traffic. Variable rotor speed for these vehicles is required for efficient high-speed operation. Two-speed drive system research has been performed to support these advanced rotorcraft applications. Experimental tests were performed on two promising two-speed transmission configurations. The offset compound gear (OCG) transmission and the dual star/idler (DSI) planetary transmission were tested in the NASA Glenn Research Center variable-speed transmission test facility. Both configurations were inline devices with concentric input and output shafts and designed to provide 1:1 and 2:1 output speed reduction ratios. Both were designed for 200 hp and 15,000 rpm input speed and had a dry shift clutch configuration. Shift tests were performed on the transmissions at input speeds of 5,000, 8,000, 10,000, 12,500, and 15,000 rpm. Both the OCG and DSI configurations successfully perform speed shifts at full rated 15,000 rpm input speed. The transient shifting behavior of the OCG and DSI configurations were very similar. The shift clutch had more of an effect on shifting dynamics than the reduction gearing configuration itself since the same shift clutch was used in both configurations. For both OCG and DSI configurations, low-to-high speed shifts were limited in applied torque levels in order to prevent overloads on the transmission due to transient torque spikes. It is believed that the relative lack of appreciable slippage of the dry shifting clutch at operating conditions and pressure profiles tested was a major cause of the transient torque spikes. For the low-to-high speed shifts, the output speed ramp-up time slightly decreased and the peak out torque slightly increased as the clutch pressure ramp-down rate increased. This was caused by slightly less clutch slippage as the clutch pressure ramp-down rate increased

Gravitational wave, collider and dark matter signals from a scalar singlet electroweak baryogenesis

We analyse a simple extension of the SM with just an additional scalar singlet coupled to the Higgs boson. We discuss the possible probes for electroweak baryogenesis in this model including collider searches, gravitational wave and direct dark matter detection signals. We show that a large portion of the model parameter space exists where the observation of gravitational waves would allow detection while the indirect collider searches would not.Ankit Beniwal, Marek Lewicki, James D. Wells, Martin White, Anthony G. William

Modular Acquisition and Stimulation System for Timestamp-Driven Neuroscience Experiments

Dedicated systems are fundamental for neuroscience experimental protocols that require timing determinism and synchronous stimuli generation. We developed a data acquisition and stimuli generator system for neuroscience research, optimized for recording timestamps from up to 6 spiking neurons and entirely specified in a high-level Hardware Description Language (HDL). Despite the logic complexity penalty of synthesizing from such a language, it was possible to implement our design in a low-cost small reconfigurable device. Under a modular framework, we explored two different memory arbitration schemes for our system, evaluating both their logic element usage and resilience to input activity bursts. One of them was designed with a decoupled and latency insensitive approach, allowing for easier code reuse, while the other adopted a centralized scheme, constructed specifically for our application. The usage of a high-level HDL allowed straightforward and stepwise code modifications to transform one architecture into the other. The achieved modularity is very useful for rapidly prototyping novel electronic instrumentation systems tailored to scientific research.Comment: Preprint submitted to ARC 2015. Extended: 16 pages, 10 figures. The final publication is available at link.springer.co

Offset Compound Gear Inline Two-Speed Drive

A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction

Henryk Bracton o królu w systemie średniowiecznego prawa angielskiego

‘De legibus et consuetudinibus Angliae’ is a first comprehensive book of whole English law properlyunderstood (even if work attributed to Glanville precedes it in time it still must be judged tobe much inferior). It represents a major turning point in history of English law, point at whichauthor of this work, to quote Holdsworth, ‘used Roman terms to describe fully English legal system’.Author of this monumental milestone is called Henry de Bracton, even though today it iscertain that man by that name did not wrote whole of the treatise himself. ‘De legibus’ influencednot only development of native English legal system but also – perhaps more importantly – thatof English political thought. It is in ‘De legibus’ where many of the most important English politicaltraditions are first founded – chief among them an idea of ‘king under the law’, a king whois made by the law, and not the other way around. For this idea to be properly understood a carefulexamination of ideas of justice, law itself and government is needed – and when conducted, itreveals a system much more intricate and complex than one could judge by later use of supposedlyBractonian ideas. For Bracton, king is chiefly a judge, a dispenser of heavenly justice boundto his duties by legal contract made during his coronation oath, and when he stops operating accordingto these rules (which do not necessarily mirror human, earthly laws) he loses his kinglystatus

Filozofia polityczna Cyropedii Ksenofonta

Xenophon’s ‘Cyropaedia’, or ‘The Education of Cyrus’, is the most important literary achievementon one of the most interesting Socratics. It tells a story of Persian king Cyrus, successful conquerorand ruler, from his upbringing at the Median court of his grandfather up until his last breath.‘Cyropaedia’ is however not a biographical account of great monarch’s deeds (although argumentsfor that are brought up in the paper), but a work akin to Plato’s ‘Republic’. In his longestwork Xenophon combines characteristic traits of many different genres – a novel, an encomium,a military treatise and so on – to construct his own unique narrative, and through that narrativeestablishes his own idea of a perfect government. Athenian philosopher judiciously weaves a taleof human nature, divine order and social phenomena to present a powerful argument for aristocraticmonarchy, in which a perfect king (a ‘speaking law’) rules by his own perfect wisdom

Offset Compound Gear Inline Two-Speed Drive

A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction