Low distortion automatic phase control circuit

A voltage controlled phase shifter is rendered substantially harmonic distortion free over a large dynamic input range by employing two oppositely poled, equally biased varactor diodes as the voltage controlled elements which adjust the phase shift. Control voltages which affect the bias of both diodes equally are used to adjust the phase shift without increasing distortion. A feedback stabilized phase shifter is rendered substantially frequency independent by employing a phase detector to control the phase shift of the voltage controlled phase shifter

Low distortion automatic phase control circuit

Circuit for generation and demodulation of quadrature double side band signals in frequency division multiplexing system is described. Circuit is designed to produce low distortion automatic phase control. Illustration of circuit and components is included

Strategisk analyse og verdsetjing av DNO

Vi har i denne utredninga føreteke ein strategisk rekneskapsanalyse og verdsetjing av DNO ASA, som er eit heilintegrert olje- og gasselskap. Gjennom den strategiske analysen avdekkja vi at oljebransjen har hatt ein bransjeorientert strategisk fordel dei seinare åra og at framtidsutsiktene framleis er lyse, men at det og er knytt vesentlig risiko til potensielle substituttar og intern rivalisering. Profitten og forventningane i bransjen er sterkt avhengig av oljeprisen til ei kvar tid. For DNO meinar vi det eksisterer interne ressursar som organisasjonsstruktur, kompetanse og omdøme som om dei vert forvalta rett kan gi dei ein varig strategisk fordel. Rekneskapsanalysen viste at selskapet både har god likviditet og soliditet, samt at rentabiliteten har vore god dei siste åra. Med bakgrunn i den strategisk rekneskapsanalysen utarbeida vi framtidsrekneskap og framtidsbalanse. Dette gav oss moglegheit til å foreta ei fundamental verdsetjing av DNO. Etter konvergering vart estimatet vårt målt opp mot børskursen og vi valte ein handlestrategi utifrå dette. Med vårt estimat på 47 pr aksje mot børskursen på 53 den 31.05.06 er vår tilråding å redusere behaldninga av DNO-aksjar. Sensitivitetsanalysen peikar på at det herskar stor uvisse i estimatet, særlig til forventningar om oljeprisen i framtida, og dette må ein ha med i tankane når ein vurderer handling

Matrix isolation as a tool for studying interstellar chemical reactions

Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques

Incorporating interactive 3-dimensional graphics in astronomy research papers

Most research data collections created or used by astronomers are intrinsically multi-dimensional. In contrast, all visual representations of data presented within research papers are exclusively 2-dimensional. We present a resolution of this dichotomy that uses a novel technique for embedding 3-dimensional (3-d) visualisations of astronomy data sets in electronic-format research papers. Our technique uses the latest Adobe Portable Document Format extensions together with a new version of the S2PLOT programming library. The 3-d models can be easily rotated and explored by the reader and, in some cases, modified. We demonstrate example applications of this technique including: 3-d figures exhibiting subtle structure in redshift catalogues, colour-magnitude diagrams and halo merger trees; 3-d isosurface and volume renderings of cosmological simulations; and 3-d models of instructional diagrams and instrument designs.Comment: 18 pages, 7 figures, submitted to New Astronomy. For paper with 3-dimensional embedded figures, see http://astronomy.swin.edu.au/s2plot/3dpd

Tunneling Time Distribution by means of Nelson's Quantum Mechanics and Wave-Particle Duality

We calculate a tunneling time distribution by means of Nelson's quantum mechanics and investigate its statistical properties. The relationship between the average and deviation of tunneling time suggests the exsistence of ``wave-particle duality'' in the tunneling phenomena.Comment: 14 pages including 11 figures, the text has been revise

Bohmian arrival time without trajectories

The computation of detection probabilities and arrival time distributions within Bohmian mechanics in general needs the explicit knowledge of a relevant sample of trajectories. Here it is shown how for one-dimensional systems and rigid inertial detectors these quantities can be computed without calculating any trajectories. An expression in terms of the wave function and its spatial derivative, both restricted to the boundary of the detector's spacetime volume, is derived for the general case, where the probability current at the detector's boundary may vary its sign.Comment: 20 pages, 12 figures; v2: reference added, extended introduction, published versio