On the best location of signal detectors

An event may occur anywhere in a planar area or on a linear region such as a route. One or more detectors are to be located within this region with the objective of maximizing the smallest probability of the detection of an event anywhere in the region. In other words, the minimum protection in the region is to be maximized. The probability that an event is detected by a detector is a decreasing function of the distance. For example, the probability may decrease with some power (say, 2) of distance, or this decrease could be approximately exponential with distance. Two solution procedures are proposed for the problem on a line segment: a mathematical programming model and a specially designed algorithm. The problem in an area is solved by a univariate search, a Demjanov-type algorithm, a mathematical programming model, and simulated annealing. Computational experience is reported.     

Testing the self as a control system: Theoretical and methodological issues

This report describes an evolution of research methodology for adducing evidence regarding whether the self functions as a control system. While there has been a great number of studies in the literature on personality and social psychology aimed at demonstrating that behavior of many kinds can be affected by focusing attention upon the subject's self-concept, or by challenging or threatening it, little attention has been given to the question of why this would be so. A proposed explanation would be that the self functions as a control system. Testing this hypothesis has entailed development of a methodological approach in which control action occurs predictably rather than having a statistical probability. This has required defining a model and testing it by predictions rather than attempting to isolate underlying variables with multivariate techniques.     

A simple method to create buttonhole cannulation tracks in a busy hemodialysis unit

The preference for fistulae as the hemodialysis access of choice has led to a significant number of accesses that are less than ideal for cannulation. Buttonhole cannulation is ideal for such accesses, but the technique for creation provides major challenges. In 12 patients, buttonhole tunnel tracks were created by leaving the polyurethane catheter of a Clampcath^® hemodialysis needle indwelling for 10 days after the initial cannulation. After each dialysis the catheter was flushed, and dressed with an antibacterial ointment and gauze. Dialysis was carried out via the catheter during that time. After day 10, the catheter was removed, the tunnel track covered with an antibacterial dressing and the tunnel track was cannulated with a dull buttonhole needle at the next dialysis. Successful buttonhole accesses were created in 11 patients after 10 days, the 12th patient required a single sharp needle cannulation before using dull needles. During the first 2 weeks of dull needle cannulation both pain experienced on cannulation and the difficulty cannulating the access were significantly less than in the classical buttonhole technique (P<0.01). Complications during the follow-up period (6 months–1.5 years) included difficulty cannulating with a dull needle (22) and antibacterial agent induced contact dermatitis (4). There was no episode of sepsis or tunnel track infection. Initial cannulation of the fistula using a Clampcath^® hemodialysis needle, leaving the polyurethane catheter indwelling for 10 days, is a simple, safe, and effective technique for the creation of buttonhole tunnel tracks.     

Generation of coherent soft x-rays using a single-pass free-electron laser amplifier†

We consider a single-pass free-electron laser (FEL) amplifier, driven by an rf-linac followed by a damping ring for reduced emittance, for use in generating coherent light in the soft x-ray region. The dependence of the optical gain on electron-beam quality, studied with the three-dimensional FEL simulation code FELEX, is given and related to the expected power of self-amplified spontaneous emission. We discuss issues for the damping ring designed to achieve the required electron-beam quality. The idea of a multipass regenerative amplifier is also presented.     

Integrity of pressurized components with localized corrosion under internal pressure and transient thermal loading

This paper is devoted to the modelling and analysis of the problem of the safety and residual lifetime of pressurized components (e.g. pressure vessels, apparatus, pipelines) with zones of local corrosion damage. Corrosion damage is the most common form of structural material degradation in service conditions, in particular, in the chemical and gas, and oil industries. Attention is paid to nonstationary regimes of the component operation, e.g., start‐stop regimes. It is shown that the critical parameters calculated taking into account the nonstationary loading can be lower compared with ones determined for the stationary regimes, e.g., on the basis of the ASME Code B31G.     

Vaporization of Rare-Earth Oxides

A study of the vaporization of La₂O₃, Nd₂O₃, and Y₂O₃ at high temperatures has been carried out by the Knudsen effusion technique. The methods employed, the results of the measurements, and the low-temperature heat capacities of these materials, which were determined for the purpose of calculating thermal functions of the oxides, are discussed. All the foregoing oxides react with tantalum, forming gaseous tantalummonoxide as a principal product. Cubic tantalates of lanthanum and neodymium are also formed in these reactions.     

STABILITY OF FIELD DEPENDENCE IN CHRONIC ALCOHOLIC PATIENTS.

62 ALCOHOLIC PATIENTS WERE ADMINISTERED THE WITKIN ROD AND FRAME TEST BEFORE AND AFTER 8-10 WK. OF PSYCHIATRIC TREATMENT. THERE WAS SIGNIFICANTLY GREATER FIELD-INDEPENDENT PERFORMANCE FOLLOWING TREATMENT. THESE RESULTS TEND TO CAST DOUBT ON THE HYPOTHESIS THAT PERFORMANCE ON THE ROD AND FRAME TEST IS STABLE AND UNAFFECTED BY CHANGES IN BODY STATE. (PsycINFO Database Record (c) 2010 APA, all rights reserved)