Some safety considerations in laser-controlled thermonuclear reactors

The potential safety problems which might be encountered in laser-driven controlled thermonuclear reactors (LCTR) have been examined and compared with previous studies of magnetically-confined systems. In several significant ways, including tritium hazards and some blanket cooling functions, laser-driven systems appear to differ only in quantitative ways from magnetic systems. Several aspects of safety of laser-driven systems are distinctive to them. These include cooling means designed to handle the pulsetile energy deposition from pellet explosions, and various equipment and containment penetrations associated with the lasers. Specify safety analyses have been performed for a loss-of-flow accident (LOFA) in a wetted-wall LCTR, and failure modes for laser penetrations are considered in detail to ascertain appropriate component placement and design criteria.     

Economy of description by parsers,DPDA's,and PDA's

It is shown that there is a sequence of languages E₁, E₂,… such that every correct prefix parser (one which detects errors at the earliest possible moment, e.g., LR or LL parsers) for E_n has size 2^cn, yet a deterministic PDA recognizing E_n exists and has size O(n²). There is another easily described sequence of languages N₁, N₂,… for which N has a nondeterministic PDA of size O(n²), but no deterministic PDA of size less than 2^cn. It is shown moreover, that this latter gap can be made arbitrarily large for different sequences of languages.     

Bandpass channels, zero-crossings, and early visual information processing.

Under appropriate conditions zero-crossings of a bandpass signal are very rich in information. The authors examine here the relevance of this result to the early stages of visual information processing, where zero-crossings in the output of independent spatial-frequency-tuned channels may contain sufficient information for much of the subsequent processing.     

A New Process for the Selective Hydrogenation of Cyclopropenoids in Cottonseed Oil

A new process has been developed, in which the cyclopropenoid groups in cottonseed oil can be selectively and continuously hydrogenated under mild conditions. This process utilizes nickel in a fixed-bed reactor, thereby eliminating the ex-pensive filtration commonly associated with slurry reactors. In pilot-plant runs at essentially atmospheric pressure and at temperatures from 150 to 315P (66-157C), Halphen-negative oils were produced in as short a contact time as 2 min. Little or no hydrogenation or isomerization of normal fatty acids occurred during the process. Reaction rate data indicate that cyclopropenoid removal follows first-order behavior.     

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.     

Spontaneous cognition and HIV risk behavior.

Theories of cognitive processes and risk behavior have not usually addressed spontaneous forms of cognition that may co-occur with, or possibly influence, behavior. This study evaluated whether measures of spontaneous cognition independently predict HIV risk behavior tendencies. Whereas a trait-centered theory suggests that spontaneous cognitions are a by-product of personality, a cognitive view hypothesizes that spontaneous cognitions should predict behavior independently of personality. The results revealed that spontaneous cognition was an independent predictor of behavior tendencies in cross-sectional analyses. Its predictive effect was stronger than drug use, a frequently emphasized correlate of HIV risk behavior in the literature, and comparable with sensation seeking in magnitude. The results suggested that a relatively spontaneous form of cognition may affect HIV risk behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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