Control of holding currents in amorphous threshold switches

It is usually assumed that the holding current of an amorphous semiconductor threshold switch is not strongly dependent on the circuit surrounding the switch. This paper shows that the holding current is in fact controlled by both the series resistance and the parallel capacitance, according to two simple inequalities. In order to obtain low holding currents a large series resistor and minimum parallel capacitance are required, and in this way a holding current of 10 μA has been observed. Data are also presented on the effects of device dimensions and temperature on the on-state I-V curves and holding current.     

Structure of the laser annealed Si(1 1 1)-(1 × 1) surface

LEED analysis of the laser annealed Si(1 1 1)-(1 × 1) surface shows that a model with a graphite-like top double layer of atoms with a spacing of 2.95±0.02 Å from the second double layer describes the LEED data as well as the Zehner model, but involves large displacements of the atoms normal to the surface as required by ion scattering results. It is suggested that this model provides a natural interpretation of the low energy He atom scattering data for the Si(1 1 1)-(7 × 7) surface.     

The influence of background power on the performance of an ideal bolometer

The effects of radiant power loading on the performance of an ideal bolometer are analysed. The operation of the bolometer is characterized in terms of dimensionless parameters which correspond to the temperature sensitivity of the thermometric material, the electrical bias point and the amount of optical power loading. Expressions are derived for the zero frequency NEP and responsivity. Examples are given for the case of a bolometer cooled to 100 mK and used for ground-based astronomical photometry at submillimetre wavelengths.     

Testing for non-locally correlated particle motions in the hydrogen atom

We report on an experiment to test for a separate proton spectrum for hydrogen. The null results is in direct violation with the predictions of local hidden variable theories, and supports either non-local quantum potential theories or an “orthodox” (Copenhagen) interpretation of quantum mechanics, where the reality of particles is not conserved.     

Heliuim-3 mass spectrometry for low-level tritium analysis of environmental samples

Helium-3 (³He) mass spectrometry for the analysis of low-level tritium (³H) concentrations (0.5 to 5 Bq·l^–1) in environmental sample matrices was compared with conventional low-level -decay counting methods. The mass-spectrometry method compared favorably, equalling or surpassing conventional decay-counting methods with respect to most criteria. Additional research and method refinements may make³He mass spectrometry the method of choice for routine, low-level to very-low-level (L<0.5 Bq·l^–1)³H measurements in a wide variety of environmental samples in the future.     

The rapid spectrophotometric determination of vanadium in tool steel with l-[(6-methyl-2-pyridyl)azo]-2-hydroxynaphthalene N-Oxide

Summary An extractive-spectrophotometric method for the determination of vanadium in tool steel is described. The only sample pretreatment required is dissolution. An average vanadium value of 2.06% was obtained on a standard sample compared to the recommended value of 2.06%.

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Eine rasche spektrophotometrische Bestimmung von Vanadin in Werkzeugstahl mit 1-[(6-Methyl-2-pyridyl)azo]-2-hydroxynaphthalin-N-oxid

Zusammenfassung Eine extraktions-spektrophotometrische Methode zur Bestimmung von Vanadin in Werkzeugstahl wurde beschrieben. Die einzige Vorbehandlung der Probe besteht in deren Auflösung. Der durchschnittlich gefundene Vanadingehalt in einer Standardprobe betrug 2,06% und stimmte mit dem angegebenen Vanadingehalt genau überein.

     

The spectrophotometric determination of scandium with disodium 3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2,7-naphthalenedisulfonate N-oxide

Summary The application of the named compound for the spectrophotometric determination of scandium is described. The effects due to pH, reagent concentration, time and diverse ions are reported. Beer's law is obeyed and the molar absorbance coefficient at 555 nm is 1.55×10⁴. By using a cupferron extraction prior to analysis, the procedure is quite selective.

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Spektrophotometrische Bestimmung von Scandium mit Dinatrium-3-hydroxy- 4-[(6-methyl-2-pyridyl)azo]-2,7-naphthalindisulfonat-N-oxid

Zusammenfassung Die Anwendung der genannten Verbindung für die spektrophotometrische Bestimmung von Scandium wurde beschrieben. Der Einfluß des pH, der Reagenskonzentration, der Zeit und verschiedener Ionen wurde untersucht. Das Beersche Gesetz wird befolgt, der molare Absorptionskoeffizient bei 555 nm beträgt 1,55×10⁴. Nach vorhergehender Cupferron-Extraktion ist das Verfahren selektiv.