Band Engineering in Cooper-Pair Box: Dispersive Measurements of Charge and Phase

Low-frequency susceptibility of the split Cooper-pair box (SCPB) is investigated for use in sensitive measurements of external phase or charge. Depending on the coupling scheme, the box appears as either inductive or capacitive reactance which depends on external phase and charge. While coupling to the source-drain phase, we review how the SCPB looks like a tunable inductance, which property we used to build a novel radio-frequency electrometer. In the dual mode of operation, that is, while observed at the gate input, the SCPB looks like a capacitance. We concentrate on discussing the latter scheme, and we show how to do studies of fast phase fluctuations at a sensitivity of 1 mrad/$\sqrt{Hz}$ by measuring the input capacitance of the box.Comment: LT24 invited paper, 4 page

“Show up and hope”: GEAR UP in an Urban High School

This research explores the factors that contribute to or detract from the success of college access programs in urban high schools through a case study of GEAR UP at a Philadelphia school. Programs like GEAR UP have real potential to help prepare students for college, but there is a need for stronger program evaluation. First, this study uses existing literature to create a framework for evaluating program effectiveness; this framework is then applied to a GEAR UP program in Philadelphia. Then, the study analyzes the factors that affected GEAR UP’s implementation at the high school. This article determines that the program was not implemented successfully because of competition with other similar programs and because of a lack of collaboration between program partners. The study concludes with a discussion of the implications of the findings for both the School District of Philadelphia and other large urban school districts

The Effectiveness of Balance Training Exercise in Post Stroke Individuals Using the Neurocom Balance Master® System

A case study was completed on a 51-year-old female who suffered a stroke in 1996 and exhibited left-sided hemiplegia. The case study examined the effects of a six-week balance training program on an individual at least six months post stroke using a force platform system called the NeuroCom Balance Master®. Individuals suffering a stroke often times exhibit deficits in balance due to weakness, sensory loss, impaired righting reflexes, and visuospatial distortion. The goal of the training program was to improve the subject\u27s balance deficits by focusing on areas of symmetrical weight bearing, weight shifting, and coordination of movement. Initial and final assessments were conducted using the NeuroCom Balance Master® and the Tinnetti Assessment Tool to assess any change in the subject\u27s balance. At the conclusion of the six-week training program, the subject improved in areas of static and dynamic balance and the ability to weight shift in the anterior direction and to her hemiparetic left side. The subject\u27s gait pattern also improved in terms of step length, step width, and step speed. Therefore, the results of this study seem to indicate that post stroke individuals of at least six months may have the ability to improve their overall balance with continued postural training. However, further research is necessary to determine the functional outcomes of postural feedback training and the reasons for improvement seen on the NeuroCom Balance Master.

Reduced gravity multibody dynamics testing

The Final Report on reduced gravity multibody dynamics testing is presented. Tests were conducted on board the NASA KC-135 RGA in Houston, Texas. The objective was to analyze the effects of large angle rotations on flexible, multi-segmented structures. The flight experiment was conducted to provide data which will be compared to the data gathered from ground tests of the same configurations. The flight and ground tested data will be used to validate the TREETOPS software, software which models dynamic multibody systems, and other multibody codes. The flight experiment consisted of seven complete flights on board the KC-135 RGA during two one-week periods. The first period of testing was 4-9 Apr. 1993. The second period of testing was 13-18 Jun. 1993

Accessing nanomechanical resonators via a fast microwave circuit

The measurement of micron-sized mechanical resonators by electrical techniques is difficult, because of the combination of a high frequency and a small mechanical displacement which together suppress the electromechanical coupling. The only electromagnetic technique proven up to the range of several hundred MHz requires the usage of heavy magnetic fields and cryogenic conditions. Here we show how, without the need of either of them, to fully electrically detect the vibrations of conductive nanomechanical resonators up to the microwave regime. We use the electrically actuated vibrations to modulate an LC tank circuit which blocks the stray capacitance, and detect the created sideband voltage by a microwave analyzer. We show the novel technique up to mechanical frequencies of 200 MHz. Finally, we estimate how one could approach the quantum limit of mechanical systems

Balmer Line Variations in the Radio-Loud AGN PG 1512+370

We present spectroscopic observations of the quasar PG~1512+370, covering the Hbeta line spectral range and collected at moderate resolution (2-7 A FWHM) from 1988 to 1996. The observations show that the blue wing of the Hbeta broad profile component has changed significantly in flux and shape between 1988 and 1990 and between 1995 and 1996. A displaced blue peak on the Hbeta profile, visible in 1988, but not in the 1990-1995 spectra, is revealed again in one of the spectra obtained in 1996. The blue peak (in both the 1988 and 1996 spectra) is centered at Delta v_r ~ -3000 +/- 500 km/s from the rest frame defined by the narrow component of Hbeta, and the OIII lambda4959,5007 lines. We discuss several conflicting interpretations of the data. We find that the variability of the Hbeta blue wing is consistent with Balmer line emission from regions whose motion is predominantly radial, if variations of the blue wing are a response to continuum changes. Alternatively, we note that observed Hbeta line profile variations are consistent with a variable line component as in a ``binary black hole'' scenario. More frequent observations of Hbeta are needed to distinguish among these hypotheses.Comment: 19 pages, 1 embedded figure (eps), to appear in ApJ 49