On amenability and co-amenability of algebraic quantum groups and their corepresentations

We introduce and study several amenability properties for unitary corepresentations and *-representations of algebraic quantum groups, which may be used to characterize amenability or co-amenability of such groups. As a background for this study, we also investigate the involved tensor C*-categories.Comment: 46 pages, (some misprints corrected, a couple of remarks and a new reference added

The Stellar Content of Obscured Galactic Giant H II Regions: II. W42

We present near infrared J, H, and K images and K-band spectroscopy in the giant HII region W42. A massive star cluster is revealed; the color-color plot and K-band spectroscopic morphology of two of the brighter objects suggest the presence of young stellar objects. The spectrum of the bright central star is similar to unobscured stars with MK spectral types of O5-O6.5. If this star is on the zero age main sequence, then the derived spectrophotometric distance is considerably smaller than previous estimates. The Lyman continuum luminosity of the cluster is a few times that of the Trapezium. The slope of the K-band luminosity function is similar to that for the Trapezium cluster and significantly steeper than that for the massive star cluster in M17 or the Arches cluster near the Galactic center.Comment: 30 pages, 11 figures, late

The Homflypt polynomial and the oriented Thompson group

We show how to construct unitary representations of the oriented Thompson group $\vec{F}$ from oriented link invariants. In particular we show that the suitably normalised HOMFLYPT polynomial defines a positive definite function of $\vec{F}$.Comment: To appear in Quantum Topolog

Short-term memory and vocabulary development in children with Down syndrome and children with specific language impairment

A longitudinal comparison was made between development of verbal and visuo-spatial short-term memory and vocabulary in children with Down syndrome (DS), children with specific language impairment (SLI), and typically developing children as a control group. Participants were 12 children with DS (6 males, 6 females; mean chronological age 9y 9mo [SD 2.8 mo], range 8y 6mo to 11y 4mo); nine children with SLI (4 males, 5 females; mean chronological age 3y 9mo [SD 4.8mo], range 3y 3mo to 4y 5mo); and 12 typically developing children (5 males, 7 females; mean chronological age 4y 4mo [SD 3.9mo], range 3y 3mo to 4y 3mo). Participants were matched on mental age (mean mental age 4y 3mo). All participants completed verbal short-term memory, visuo-spatial short-term memory, and expressive and receptive vocabulary tasks on three occasions over 1 year. Similarities were seen in the clinical groups for verbal short-term memory. There was some evidence of difficulty in visuo-spatial short-term memory in the children with SLI relative to the other groups, but all three groups showed overlap in visuo-spatial short-term memory performance. At the final time-point vocabulary performance in the clinical groups was similar; the typically developing children showed higher vocabulary abilities than both clinical groups

Cognitive abilities in children with specific language impairment: consideration of visuo-spatial skills

Background: The study is concerned with the cognitive abilities of children with specific language impairment (SLI). Previous research has indicated that children with SLI demonstrate difficulties with certain cognitive tasks despite normal non‐verbal IQ scores. It has been suggested that a general processing limitation might account for the pattern of language and cognitive difficulties seen in children with SLI. The performances on a visuo‐spatial short‐term memory task and a visuo‐spatial processing task were considered in a group of young children with SLI. Verbal short‐term memory was also measured. Aims: To identify whether children with SLI demonstrate difficulties with visuo‐spatial memory as well as verbal short‐term memory. To see whether a visuo‐spatial processing task without short‐term memory requirements is problematic for children with SLI. To consider performance on these tasks over time. Methods & Procedures: Nine children with SLI (mean age 3;9 years at the study outset) and nine typically developing children (mean age 3;9 years at the study outset) were visited on three occasions over 1 year. Verbal short‐term memory, visuo‐spatial short‐term memory and visuo‐spatial processing tasks were administered to the children, and performance over time was compared between the two groups. Outcomes & Results: The children with SLI performed at a lower level than the typically developing children on the verbal short‐term memory task. Both groups showed similar development on the verbal short‐term memory task and the visuo‐spatial processing task over time. Only the visuo‐spatial short‐term memory task showed slower development over time in the children with SLI relative to the typically developing children. Conclusions: Children with SLI demonstrated slower development on a visuo‐spatial short‐term memory task relative to typically developing children of the same chronological age. This finding has implications for speech and language therapists and other professionals working with children with SLI. It may mean that only certain types of visual support are suitable, and that children with SLI will have difficulty with tasks requiring a high level of processing, or a number of mental manipulations

Exchange-correlation potential for Current Density Functional Theory of frequency dependent linear response

The dynamical, long-wavelength longitudinal and transverse exchange-correlation potentials for a homogeneous electron gas are evaluated in a microscopic model based on an approximate decoupling of the equation of motion for the current-current response function. The transverse spectrum turns out to be very similar to the longitudinal one. We obtain evidence for a strong spectral structure near twice the plasma frequency due to a two-plasmon threshold for two-pair excitations, which may be observable in inelastic scattering experiments. Our results give the entire input needed to implement the Time-Dependent Current Density Functional Theory scheme recently developed by G. Vignale and W. Kohn [Phys. Rev. Lett. 77, 2037 (1996)] and are fitted to analytic functions to facilitate such applications.Comment: 6 pages, 3 figure

A near-infrared survey for Galactic Wolf-Rayet stars

Initial results, techniques, and rationale for a near-infrared survey of evolved emission-line stars toward the Galactic Center are presented. We use images taken through narrow-band emission-line and continuum filters to select candidates for spectroscopic follow-up. The filters are optimized for the detection of Wolf-Rayet stars and other objects which exhibit emission-lines in the 2 micron region. Approximately three square degrees along the Galactic plane have been analyzed in seven narrow-filters (four emission-lines and three continuum). Four new Wolf-Rayet stars have been found which are the subject of a following paper.Comment: 10 pages, 2 figures, accepted for publication in A&

Steam storage systems for flexible biomass CHP plants - Evaluation and initial model based calculation

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Within the present study a novel concept for the demand-oriented power generation of a solid-biomass fueled combined heat and power (CHP) plant is investigated. The integration of a steam storage system into the plants process enables a decoupling of the steam (boiler) and the power generation (steam turbine). By buffering the steam, the power output of the turbine can be adjusted without changing the rated thermal capacity of the plant. Various available storage systems are selected and comparatively evaluated applying the adapted analytic hierarchy process (AHP). The technology assessment revealed that the combination of a steam accumulator and solid concrete storage represents the best suiting option. An initial model based simulation study is performed to identify the fundamental behaviour of this system, integrated in a biomass CHP plant. The operation principle is has proved their technical feasibility and seems to be applicable at a commercial scale. According to the modelling results flexible short term power generation in a time range of up to fifteen minutes is applicable. A load-range of almost the plants rated capacity can be achieved

Search for T‐odd, P‐even interactions with a three‐level, directional clock

A new class of T‐violation experiments that are sensitive to the presence of parity‐conserving time‐reversal violating interactions in atoms are considered. (AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87728/2/66_1.pd