A Broadband Excimer-Halogen Emitter Utilizing Xenon Bromide and Iodide

The results are given of an investigation of the output characteristics of an electric-discharge excimer-halogen UV emitter utilizing a Xe/Br₂/J₂ mixture. A longitudinal glow discharge with an interelectrode spacing of 50 cm and inside diameter of the discharge tube of 1.4 cm is ignited at the working mixture pressure of 1 kPa and power input to the plasma of 10–350 W. A study is performed of the current-voltage characteristics of the discharge, plasma radiation spectra in the 190–350 nm range, and distributions of the brightness of radiation of molecules as a function of the pumping conditions, as well as of pressure and partial composition of the gas mixture. It is demonstrated that the plasma of the discharge being investigated is a source of broadband UV radiation in a system of bands of 253 nm XeJ, 282 nm XeBr, and 292–310 nm Br₂ ^*, which are joined by the radiation of resonance line of iodine atom with = 206 nm. The total power of UV radiation of plasma increases linearly with the electrical power of the glow discharge.     

Automatic identification of bacterial types using statistical imaging methods

The objective of the current study is to develop an automatic tool to identify microbiological data types using computer-vision and statistical modeling techniques. Bacteriophage (phage) typing methods are used to identify and extract representative profiles of bacterial types out of species such as the Staphylococcus aureus. Current systems rely on the subjective reading of profiles by a human expert. This process is time-consuming and prone to errors, especially as technology is enabling the increase in the number of phages used for typing. The statistical methodology presented in this work, provides for an automated, objective and robust analysis of visual data, along with the ability to cope with increasing data volumes.     

Dialogue Abner Shimony–Shimon Malin

Malin proposes a solution to some of the conceptual problems of the foundations of quantum mechanics within the framework of Alfred North Whitehead’s “Philosophy of Organism”. Standard quantum dynamics, governed by the time-dependent Schr?dinger equation, does not provide for the reduction of superpositions of physical states and hence does not account for occurrence of observational data. If consciousness is invoked to explain the results of measurements, it would appear that quantum mechanics is given an anthropocentric interpretation. Reduction of superpositions is achieved without anthropocentrism, according to Malin, by accepting Whitehead’s ontology of “actual occasions”, which are protomental entities independent of and presumably antedating human beings. Furthermore, Whitehead’s philosophy has the great virtue of offering a plausible solution to the profound problem of relating minds to material systems. Shimony is sympathetic to Whitehead’s world view, but with the reservation that it leaves an immense unexplained and unexplored gap between the conjectured “experience” of actual occasions and the high level experience of the human mind.QUPON/QIPC Special Issue     

A hierarchical non-parametric method for capturing non-rigid deformations

We present a novel approach for measuring image similarity based on the composition of parts. The measure identifies common sub-regions between the images at multiple sizes, and evaluates the amount of deformation required to align the common regions. The scheme allows complex, non-rigid deformation of the images, and penalizes irregular deformations more than coherent shifts of larger sub-parts. The measure is implemented by an algorithm which is a variant of dynamic programming, extended to multi-dimensions, and is using scores measured on a relative scale. The similarity measure is shown to be robust to non-rigid deformations of parts at various positions and scales, and to capture basic characteristics of human similarity judgments.     

Carrier Phase Recovery Scheme for a Low-Frequency Vestigial Sideband Video Transmission System

A vestigial sideband system seems attractive for transmitting video signals over media of limited bandwidth. Linearity constraints in the unavoidable intermediate equalizers (repeaters) limit the level of the transmitted carrier to such an extent that envelope detection is precluded. In a proposed video system the transmitted signal includes a partially suppressed carrier and an out-of-band pilot tone. At the receiver a voltage of the exact carrier frequency is regenerated from this pilot tone. But synchronous detection of a video signal requires the exact phase of the incoming carrier as well. Distortion considerations limit the width of the guard bands around the partially suppressed carrier to such an extent that conventional filtering cannot be used to retrieve its phase. A special type of a phase-locked loop which adjusts the phase of the locally generated carrier to that of the incoming partially suppressed one was therefore designed and tested. Design considerations, circuit diagrams and test results for this circuit are presented here. Subjective tests have demonstrated the feasibility of the proposed system for transmitting a video signal of 1-MHz bandwidth over a repeatered twisted pair.     

Regiocontrolled Synthesis of 4-Halo-5,6-Dihydro-4H-1,2-Oxazines; A Novel Route for α-Fluorovinyl Ketones

Regiocontrolled deprotonation (e.g. lithiation) of 3-methyl-4-H-5,6-dihydro-1,2-oxazine 1 is achieved at −65°C. The lithiated compound reacts cleanly with the halogens Cl₂, Br₂ and I₂ at low temperatures (−65°C) to give the corresponding 4-halo derivatives. Reaction of the 4-iodo compound 2a with KF in diethyleneglycol gives the elimination product 4 whereas the bromo compound 2b reacts under substitution to the 4-fluoro derivatives 5. The fluorooxazine derivatives 8a-c were converted to the αfluoroenones 11 a-c via the oxoiminium salts 10a-c. The U.V. and ¹HNMR of the novel series of halides 2a-c and 5 were studied.     

Crystallization and morphology of isotactic poly(methyl methacrylates)

Several isotactic poly (methyl methacrylates) (iPMMA), with isotactic triad contents ranging from 46 to 100%, have been investigated after crystallization in the melt at different temperatures by differential scanning calorimetry, polarizing microscopy and small-angle light scattering. It was found that the crystallization of iPMMA, even of samples with high isotactic content, is slow. It never gives high degrees of crystallinity, but nevertheless leads to a spherulitic structure.     

Electronic-Vibrational Spectroscopy of Large van der Waals Molecules

In this paper we focus on the electronic-vibrational spectra of tetracene · A₁ (A = Ar, Kr, Xe) heteroclusters, which provide information on the intermolecular nuclear motion of a rare-gas atom on the microsurface of a large aromatic molecule. Calculations of the energy levels and nuclear Franck-Con-don factors for the excitation of the parallel and perpendicular intermolecular vibrations in the electronic S₀ → S₁ excitation of heteroclusters were performed. The experimental energetic and intensity data for the perpendicular intermolecular nuclear excitation are well accounted for by our calculations. This study provides some information regarding the potential surfaces of large heteroclusters in electronically excited states, which are important for the elucidation of the spectroscopy, nuclear motion, and isomerization dynamics of large aromatic molecule · (rare gas)n heteroclusters.