On the application of complex resistive boundary conditions tomodel transmission lines consisting of very thin superconductors

A resistive boundary condition for the case where the resistivity is assumed to be a complex quantity is shown to be an accurate model for a superconducting film which is thin compared to the super-conducting penetration depth. The imaginary part of the conductivity is the dominant terms and is a measure of the inductive energy stored in the superconductor. Numerical solutions of superconducting microstrip are obtained and compared to experimental results and to analytic solutions for superconducting parallel-plate waveguides. Excellent agreement is found between experimental, analytical, and numerical results     

Backscattered electron imaging of dental amalgam

A study of the microstructure of set dental amalgams has been undertaken using techniques of back-scattered electron imaging, transmission electron microscopy and X-ray analysis. It has been demonstrated that small ( 0.2, m) particles of a copper-tin phase are present in the matrix of the conventional low-copper amalgams and that the reaction zone around the silver copper eutectic phase in the high copper dispersion type amalgams is of a duplex nature consisting of the Cu₆Sn₅, phase and an intervening layer of silver-mercury phase.     

The gas-cooled fast breeder reactor critical experiments program

This paper presents results of measurements and calculations of physics parameters in the first gas-cooled fast breeder reactor (GCFR) critical assemblies in the US, a program of experiments conducted on the ZPR-9 facility at Argonne National Laboratory. Through a progressive three-phase series of assemblies, the major features unique to GCFR physics due to the gaseous coolant, and the resulting hard neutron spectrum and greater leakage, were investigated. Phases I and II were simple-geometry, uniform-core assemblies providing tests of nuclear data and GCFR design methods for fast reactors with large void fractions. The Phase III core simulates a GCFR design with three enrichment zones. This report primarily concerns the results obtained in Phase II.In addition to the usual central indices, reaction rate mappings, etc. these initial studies have provided the first experimental data on reactivity coefficients relevant to GCFR safety, such as worths of fuel, control, and cladding materials, Doppler effect, and coolant (helium) depressurization worth. Effects of steam ingress into coolant channels (due to a hypothesized steam generator leak) were simulated using polyethylene. The physics information obtained is providing a valuable base for verification of GCFR design and safety analyses.     

Tuning in to psychological change: Linguistic markers of psychological traits and emotions over time in popular U.S. song lyrics.

American culture is filled with cultural products. Yet few studies have investigated how changes in cultural products correspond to changes in psychological traits and emotions. The current research fills this gap by testing the hypothesis that one cultural product—word use in popular song lyrics—changes over time in harmony with cultural changes in individualistic traits. Linguistic analyses of the most popular songs from 1980–2007 demonstrated changes in word use that mirror psychological change. Over time, use of words related to self-focus and antisocial behavior increased, whereas words related to other-focus, social interactions, and positive emotion decreased. These findings offer novel evidence regarding the need to investigate how changes in the tangible artifacts of the sociocultural environment can provide a window into understanding cultural changes in psychological processes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Contributions of automatic and controlled processes to the analysis of hierarchical structure.

Three experiments provide evidence that 2 mechanisms, 1 automatic and 1 controlled, produce variations in the efficiency with which local and global forms are processed. Targets are identified faster if they appear at the same level (global or local) as the target on the previous trial. M. R. Lamb, B. London, H. M. Pond, and K. A. Whitt (see record 1997-39043-003) provided evidence that the beneficial effect of level repetition is due to an automatic process that is outside voluntary control. In the present experiments, pretrial cues informed participants as to the level of the upcoming target. Valid cues benefited performance, whereas invalid cues harmed performance relative to noninformative neutral cues. This was so even when the relation between the cue and the level it signaled was arbitrary, indicating that the cues initiated voluntary shifts of attention. The benefit associated with level repetition, however, was unaffected by the cues. These data suggest that the benefit of level repetition results from a process that is not subject to voluntary control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preliminary Investigation into the Microbiological Quality of a Freshwater Bathing Site: A Case for Official Identification?

The quality of recreational waters has become of increasing importance and, where water-based activities are permitted, such waters should be required to comply with minimum standards to protect public health. At present, there are no freshwater sites in the UK which are identified as official bathing areas, despite a significant proportion being identified in other EU Member States and the increasing use of such waters for bathing. This paper presents a case for the official identification of three freshwater bathing sites which, traditionally, have been used for bathing for more than ninety years.     

Superconductors and microwaves

Superconductivity, along with other cryogenic electronic technologies, can provide microwave and millimeter-wave (mm-wave) components, both passive and active, with characteristics superior to what can be realized using conventional room-temperature technologies [1], [2]. Radio astronomers have been cooling their receiver front ends to temperatures of 10 K and below for more than 50 years whereas superconductor-insulator- superconductor (SIS) devices cooled to near 4 K have been used as the mixers and detectors of preference for radio telescopes operating in the mm-wave frequency range since the 1970s. Other cryogenic electronics that date back to the 1960s include infrared focal plane arrays that were operated at temperatures of 50-70 K whenever long wavelength operation and very low noise are required. Although superconducting devices (such as high Q-value cavities) have a long history in high-energy physics (HEP) particle accelerators, other applications have not found wide use. Several factors have contributed to this situation including the lack of maturity of some of these technologies, as well as the practical fact that the cryogenic burden has been perceived as too great compared to the performance advantage that could be realized.     

Research and the problems of litter and medical wastes on the UK coastline

OBJECTIVE AND IMPORTANCE: Symptomatic cerebral vasospasm can occur after resection of tumors in or adjacent to the basal cisterns, causing delayed neurological deterioration. This potentially treatable condition may go unrecognized. Delay in its recognition will adversely affect the outcome of the patients. There has been a few cases of vasospasm after tumoral resection reported in the literature, mostly in adults. We report a case of vasospasm after resection of a third nerve schwannoma in a pediatric patient. This is the youngest patient reported to date with vasospasm after resection of a brain tumor. CLINICAL PRESENTATION: A six years old girl presented with sudden onset diplopia. Radiological work-up revealed a third nerve mass. She underwent a craniotomy for resection of her mass. Pathological findings were consistent with a third nerve schwannoma. One week postoperatively, her mental status deteriorated. A CT scan revealed a diffuse hypodense area involving the right frontal and temporal lobes in the middle cerebral artery distribution as well as the midbrain. The absence of these findings on the MRI imaging performed on the first postoperative day made us evoke a vascular etiology. A cerebral angiogram was performed and revealed vasospasm in the right internal carotid artery and in the right middle and posterior cerebral arteries. Hyperdynamic hypervolemic hemodilutional therapy was instituted. CONCLUSION: Delayed clinical deterioration from vasospasm is a potentially reversible condition, if recognized early. A high index of suspicion should be maintained in case delayed clinical deterioration occurs after surgery of tumors in the basal cisterns. Cerebral angiography will confirm the diagnosis. Early institution of hyperdynamic hypervolemic hemodilutional therapy and angioplasty may reverse the deficit and improve outcome.     

The microstructure and recrystallization of flow-formed oxide-dispersion-strengthened ferritic alloy: Part II. Recrystallization behavior

The recrystallization behavior of four PM2000 cold flow-formed tubes deformed to levels ranging from 72 to 92 pct has been investigated. It has been found that coarse, high grain aspect ratio (GAR) hoop-oriented grain structures can be produced in Fe-based oxide dispersion strengthened (ODS) alloy tubing by appropriate combinations of flow-forming and subsequent high-temperature annealing; a flow-forming deformation of 89.6 pct produced the coarsest hoop-oriented grain structures in the present study. In the absence of obvious particle alignment, it has been suggested that the formation of hoop-oriented grain structures may be explained by the anisotropic growth of recrystallizing grains into the aligned, anisotropic deformation cell structure observed in the flow-formed tubes.