System for measuring transients in fluid flow

When test valve is actuated, piston is moved by pressurized fluid, and displacement is monitored by electro-optical tracking system and recorded by oscilloscope camera. Electro-optical monitor produces output voltage proportional to displacement of piston

Are Superhumps Good Measures of the Mass Ratio for AM CVn Systems?

We extend recent work that included the effect of pressure forces to derive the precession rate of eccentric accretion discs in cataclysmic variables to the case of double degenerate systems. We find that the logical scaling of the pressure force in such systems results in predictions of unrealistically high primary masses. Using the prototype AM CVn as a calibrator for the magnitude of the effect, we find that there is no scaling that applies consistently to all the systems in the class. We discuss the reasons for the lack of a superhump period to mass ratio relationship analogous to that known for SU UMa systems and suggest that this is because these secondaries do not have a single valued mass-radius relationship. We highlight the unreliability of mass-ratios derived by applying the SU UMa expression to the AM CVn binaries.Comment: 7 pages, 2 tables, to appear in Monthly Notices of the Royal Astronomical Societ

The ₅C₅ Survey of Radio Sources

The ₅C₅ survey, made with the Cambridge One-Mile telescope, covers an area about 4° in diameter at 408 MHz centred at α = 09ʰ40ᵐ,δ = 47∘00′ to a limiting flux density of 8⋅7 × 10⁻²⁹ Wm⁻² Hz⁻¹ at the centre, and a concentric area of diameter about 1° at 1407 MHz to a limiting flux density of 1⋅8×10−29Wm−2Hz−1⁠. The positions and flux densities of 230 sources observed at 408 MHz, and of 52 observed at I407 MHz, are listed in Table I, with suggested optical identifications for some of the sources. The flux density and spectral index distributions are similar to those of the earlier ₅C surveys and there is no evidence for significant anisotropy in either distribution. New observations of some ₅C I sources included in the ₅C₅ survey show that the flux densities measured in ₅C I were in error

Little green steps: sustainability practice for early years comes to WA.

Little Green Steps, a training workshop on education for sustainability for early years educators, was recently conducted by the Australian Association for Environmental Education - Western Australian Chapter (MEE-WAJ. With a grant from the Waste Authority of Western Australia, AAEE-WA was able to provide professional learning for staff of childcare services, kindergartens and preschools. The purpose of the training was to encourage sustainable practice through zero waste policy and practical implementation of these practices for children, staff and parents. This training was developed by Lady Gowrie Child Centre In Sydney and the Department of Environment, Climate Change and Water in New South Wales, and assisted in the setting up of the professional development component of Gosford City and Wyong Shire Councils' Little Green Steps Program. To increase national exposure to the program two days were offered in WA. Each day stood alone as a discrete training program

The 5C 6 and 5C 7 surveys of radio sources

5C 6 and 5C 7 continue the series of deep surveys made at 408 and 1407 MHz with the One-Mile telescope at Cambridge. They were intended (1) to provide a sample of faint radio sources suitable for further study; (2) to improve the statistics of source counts N(S) and spectral-index distributions at low flux densities; (3) to study the isotropy of the distribution of faint sources. Each observed field is about 4° in diameter at 408 MHz and 1° in diameter at 1407 MHz, and the field-centres are a α = 02ʰ14ᵐ, δ = 32° (5C 6) and α = 08ᵏ17ᵐ, δ = 27° (5C 7). The synthesized beamwidths (FWHM) are 80 arcsec (408 MHz) and 23 arcsec (1407 MHz). The techniques of observation and data-analysis followed closely those used for 5C 5 (Pearson, T. J., 1975. Mon. Not. R. astr. Soc., 171, 475), with some minor variations which are noted in Section 2

On spectral hypergraph theory of the adjacency tensor

We study both $H$ and $E/Z$-eigenvalues of the adjacency tensor of a uniform multi-hypergraph and give conditions for which the largest positive $H$ or $Z$-eigenvalue corresponds to a strictly positive eigenvector. We also investigate when the $E$-spectrum of the adjacency tensor is symmetric

Active Control Evaluation for Spacecraft (ACES)

The Air Force goal is to develop vibration control techniques for large flexible spacecraft by addressing sensor, actuator, and control hardware and dynamic testing. The Active Control Evaluation for Spacecraft (ACES) program will address the Air Force goal by looking at two leading control techniques and implementing them on a structural model of a flexible spacecraft under laboratory testing. The first phase in the ACES program is to review and to assess the High Authority Control/Low Authority Control (HAC/LAC) and Filter accomodated Model Error Sensitivity Suppression (FAMESS) control techniques for testing on the modified VCOSS structure. Appropriate sensors and actuators will be available for use with both techniques; locations will be the same for both techniques. The control actuators will be positioned at the midpoint and free end of the structure. The laser source for the optical sensor is mounted on the feed mast. The beam will be reflected from a mirror on the offset antenna onto the detectors mounted above the shaker table bay. The next phase is to develop an analysis simulation with the control algorithms implemented for dynamics verification. The third phase is to convert the control laws into high level computer language and test them in the NASA-MSFC facility. The final phase is to compile all analytical and test results for performance comparisons

Children at risk : their phonemic awareness development in holistic instruction

Includes bibliographical references (p. 17-19

A New Approximation of the Schur Complement in Preconditioners for PDE Constrained Optimization

Saddle point systems arise widely in optimization problems with constraints. The utility of Schur complement approximation is now broadly appreciated in the context of solving such saddle point systems by iteration. In this short manuscript, we present a new Schur complement approximation for PDE constrained optimization, an important class of these problems. Block diagonal and block triangular preconditioners have previously been designed to be used to solve such problems along with MINRES and non-standard Conjugate Gradients respectively; with appropriate approximation blocks these can be optimal in the sense that the time required for solution scales linearly with the problem size, however small the mesh size we use. In this paper, we extend this work to designing such preconditioners for which this optimality property holds independently of both the mesh size and of the Tikhonov regularization parameter \beta that is used. This also leads to an effective symmetric indefinite preconditioner that exhibits mesh and \beta-independence. We motivate the choice of these preconditioners based on observations about approximating the Schur complement obtained from the matrix system, derive eigenvalue bounds which verify the effectiveness of the approximation, and present numerical results which show that these new preconditioners work well in practice