The thermal behaviour of some rhodium complexes

The thermal behaviour of several complexes of rhodium has been investigated. Complexes containing nitrogen ligands readily decompose to the oxide, Rh₂O_3^? Complexes with phosphorus and arsenic ligands decompose to the same oxide of rhodium, although difficulty is encountered in removing all the phosphorus and arsenic. The suitability of the decomposition to Rh₂O₃ as an analytical technique for rhodium is discussed.     

Red phosphorus as a flame retardant for a thermoplastic nitrogen-containing polymer

Studies were made of the flame-retardant and smoke-suppressant activity of red phosphorus, in the presence of a brominated (decabromobiphenyl) and/or a nitrogenated (melamine) compound, on acrylonitrile-butadiene-styrene terpolymer. These studies were complemented by simultaneous thermal analyses of the polymeric systems. Red phosphorus is oxidised on heating and the thermal decomposition of any system containing this additive includes a substantial weight gain stage at ca 700 K. Melamine is volatilised very early on and thereafter acts only as a smoke suppressant in the gas phase. Decabromobiphenyl and red phosphorus interact positively in decreasing the flammability of the substrate, particularly at atomic ratios not lower than stoichiometric. The acrylonitrile content in ABS is very important, suggesting that the additives act mainly in the gas phase but that they also form some sort of charry layer on the polymer surface.     

Unequivocal syntheses of 6-methyl- and 6-phenylisoxanthopterin

Although 6-methyl- ( 1 ) and 6-phenylisoxanthopterin ( 2 ) have previously been synthesized, the requirement of high purity necessary for immunological testing has necessitated our development of the first reported synthesis of these compounds by unequivocal methods. In the process of so doing four new pyrazines, ethyl 3-amino-5-chloro-6-methyl-2-pyrazinecarboxylate ( 11 ), N,N-dimethyl-N'-(6-chloro-3-cyano-5-phenylpyrazin-2-yl)methanimidamide ( 16 ), 2-amino-3-ethoxycarbonyl-5-phenylpyrazine 1-oxide ( 19 ), and ethyl 3-amino-5-chloro-6-phenyl-2-pyrazinecarboxylate ( 20 ) were synthesized. Four new pteridines, 7-methoxy-6-methyl-2,4-pteridinediamine ( 7 ), 7-methoxy-6-phenyl-2,4-pteridinediamine ( 17 ), 2-amino-7-ethoxy-6-methyl-4(3H)-pteridinone ( 12 ), and 2-amino-7-ethoxy-6-phenyl-4(3H)-pteridinone ( 21 ) have also been synthesized enroute to these isoxanthopterins.     

Numerical evaluation of further supersonic sections including ducted heat addition and nozzle flow

Summary This paper follows earlier investigations of heat addition to the flow, both with and without ducting, past twodimensional sections in a free stream at a Much number of 7.5. The present results all refer to ducted heat addition, and two kinds of intake are investigated. One of these has just two shocks, both deflecting the flow downwards, while the other has a third shock reflected upwards from the cowl so as to reduce the incidence of the cowl and hence its drag. With the two-shock intake, the cowl is curved upwards, again to reduce drag. Values of lift coefficient, net pressure-drag coefficient and propulsive efficiency are calculated for a range of parameters (including the strength of the intake shock) with values mostly in the ranges 0.04 to 0.08,-0.03 to -0.07 and 0.5 to 0.7 respectively.

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Übersicht Frühere Untersuchungen über die Wärmezufuhr zu Strömungen unter zweidimensionalen Körpern mit oder ohne Verkleidung bei Machzahlen von 7,5 werden fortgeführt. Die jetzigen Ergebnisse beziehen sich auf Wärmezufuhr innerhalb einer Verkleidung, bei der zwei Arten von Einlaufströmungen untersucht werden: beider einen treten zwei Stoßfronten auf, die die Strömung nach unten reflektieren; bei der anderen Strömung ist eine dritte Stoßfront vorhanden, durch die der Widerstand der Verkleidung durch Ablenkung der Strömung nach der Wand hin verringert wird. Bei dem Zwei-Stoßwellen-Einlaß ist die Verkleidung nach außen gekrümmt, um den Widerstand zu verringern. Es werden Werte für den Auftriebsbeiwert, den effektiven Druck-Widerstandsbehvert und den Vortriebswirkungsgrad für verschiedene Wertebereichc der Parameter, einschließlich der Stärke des Eintrittsstoßes ausgerechnet.

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The author wishes to express his appreciation of the fact that the computer subroutines for the nozzle flow and propulsive efficiency were derived and written by Mr. Stephen J. Leese while working at the RAE as a vacation student.     

Entanglement swapping,light cones and elements of reality

Recently, a number of two-participant all-versus-nothing Bell experiments have been proposed. Here, we give local realistic explanations for these experiments. More precisely, we examine the scenario where a participant swaps his entanglement with two other participants and then is removed from the experiment; we also examine the scenario where two particles are in the same light cone, i.e. belong to a single participant. Our conclusion is that, in both cases, the proposed experiments are not convincing proofs against local realism.     

Quantum Pseudo-Telepathy

Quantum information processing is at the crossroads of physics, mathematics and computer science. It is concerned with what we can and cannot do with quantum information that goes beyond the abilities of classical information processing devices. Communication complexity is an area of classical computer science that aims at quantifying the amount of communication necessary to solve distributed computational problems. Quantum communication complexity uses quantum mechanics to reduce the amount of communication that would be classically required. Pseudo-telepathy is a surprising application of quantum information processing to communication complexity. Thanks to entanglement, perhaps the most nonclassical manifestation of quantum mechanics, two or more quantum players can accomplish a distributed task with no need for communication whatsoever, which would be an impossible feat for classical players. After a detailed overview of the principle and purpose of pseudo-telepathy, we present a survey of recent and not-so-recent work on the subject. In particular, we describe and analyse all the pseudo-telepathy games currently known to the authors. Supported in Part by Canada’s Natural Sciences and Engineering Research Council (NSERC), the Canada Research Chair programme and the Canadian Institute for Advanced Research (CIAR). Supported in part by a scholarship from Canada’s NSERC. Supported in part by Canada’s NSERC Québec’s Fonds de recherche sur la nature et les technologies (FQRNT), the CIAR and the Mathematics of Information Technology and Complex Systems Network (MITACS).     

Transmission of sound through a pair of rectangular elastic plates

^** Email: f.leppington{at}ukonline.co.uk Two thin elastic plates, which may have different physical parameters,occupy the parallel regions 0 < x < a, 0 < y < b,z = – d and 0 < x < a, 0 < y < b, z = 0, ina Cartesian coordinate system, where the separation distanced is much less than the dimensions a and b. The plates are simplyconnected to a structure that occupies the rest of the region– d < z < 0. The side walls (x = 0 or a, 0 <y < b, – d < z < 0 and y = 0 or b, 0 < x <a, – d < z < 0) are taken to be acoustically soft;the surfaces z = – d and z = 0, outside the rectangularregions occupied by the plates, are taken to be acousticallyhard. Light compressible fluid (air) is in each of the half-spacesoutside the plates and in the rectangular region between them.A sound field is induced by a high-frequency plane wave. Allowanceis made for a small element of damping in the fluid trappedbetween the plates, as well as damping in the plates. Estimatesare derived for the transmitted power, averaged over a frequencyband and with respect to all incidence directions, in the asymptoticlimits of small fluid loading and high frequency. For the casewhere the two plates have identical physical properties, detailedasymptotic estimates are given for the form of the peaks inthe transmitted power, at a discrete set of operating frequencies,both above and below the plates' coincidence frequency.     

Die Redox-Eigenschaften von Hydroxyanthrachinonsulfonsäuren II

The formation of intermediates in the reduction of two hydroxyanthraquinonesulphonic acids has been investigated by potentiometric and polarographic techniques. Acid-base properties of molecules in the redox sequences have been deduced. In certain pH regions measurements were hindered by specific physical and chemical side-reactions. Reduction in strongly alkaline solution only produces semiquinone free radical intermediates, but below pH 10 bimolecular quinhydrones may also be formed.     

Experimental and theoretical aspects of the two-roll mill problem

Experiments are described in which two cylinders of the same radii-rotate with identical speeds in a bath of Newtonian or non-Newtonian liquid. The torque on one of the cylinders is measured as a function of rotational speed for various values of the cylinder separation and the flow patterns are observed by a dye-injection technique.The observed experimental results for a Newtonian liquid correlate well with the theoretical predictions but a similar correlation in the case of elastic liquids is made difficult by the strongly three-dimensional nature of the flow in this case and the difficulty in estimating the amount of liquid passing through the rollers. The possibility of flow reversal effects due to the high Trouton ratios in the case of the elastic liquids is investigated both experimentally and theoretically.