32,924 research outputs found
NACA Flight-Path Angle and Air-Speed Recorder
A new trailing bomb-type instrument for photographically recording the flight-path angle and air speed of aircraft in unaccelerated flight is described. The instrument consists essentially of an inclinometer, air-speed meter and a film-drum case. The inclinometer carries an oil-damped pendulum which records optically the flight-path angle upon a rotating motor-driven film drum. The air-speed meter consists of a taut metal diaphragm of high natural frequency which is acted upon by the pressure difference of a Prandtl type Pitot-static tube. The inclinometer record and air-speed record are made optically on the same sensitive film. Two records taken by this instrument are shown
A Second Shell in the Fornax dSph Galaxy
In the search for tidal structure in Galactic satellite systems, we have
conducted a photometric survey over a 10 square degree area centred on the
Fornax dSph galaxy. The survey was made in two colours, and the resulting
colour-magnitude data were used as a mask to select candidate Fornax RGB stars,
thereby increasing the contrast of Fornax stars to background sources in the
outer regions. Previously, we reported the presence of a shell (age 2 Gyr)
located towards the centre of Fornax. In this contribution we reveal a second
shell, significantly larger than the first, located 1.3 degrees NW from the
centre of Fornax, outside the nominal tidal radius. Moreover, the distribution
of Fornax RGB stars reveals two lobes extending to the spatial limit of our
survey, and aligned with the minor axis and with the two shells. These results
support the hypothesis of a merger between Fornax and a gas-rich companion
approximately 2 Gyr ago.Comment: Four pages,accepted for the Publications of the Astronomical Society
of Australia. Contribution the annual ASA meeting, Brisbane 200
Measuring attendance: issues and implications for estimating the impact of free-to-view sports events
A feature of many non-elite sports events, especially those conducted in public places is that they are free-to-view. The article focuses on the methodological issue of estimating spectator attendance at free-to-view events and the consequences of this for impact evaluation. Using empirical data from three case studies, the article outlines various approaches to measuring attendance and discusses the key issues and implications for evaluating free-to-view sports events in the future
Federal incentives for industrial modernization: Historical review and future opportunities
Concerns over the aging of the U.S. aerospace industrial base led DOD to introduce first its Technology Modernization (Tech Mod) Program, and more recently the Industrial Modernization Incentive Program (IMIP). These incentives include productivity shared savings rewards, contractor investment protection to allow for amortization of plant and equipment, and subcontractor/vendor participation. The purpose here is to review DOD IMIP and to evaluate whether a similar program is feasible for NASA and other non-DOD agencies. The IMIP methodology is of interest to industrial engineers because it provides a structured, disciplined approach to identifying productivity improvement opportunities and documenting their expected benefit. However, it is shown that more research on predicting and validating cost avoidance is needed
Commutating brushes tested in dc motors in dry argon atmospheres
Test apparatus, procedures, and results are given for dc-motor brushes operating in dry argon. Minimum concentrations of argon impurities are also determined
Cell cycle regulation of a Xenopus Wee1-like kinase
Using a polymerase chain reaction-based strategy, we have isolated a gene encoding a Wee1-like kinase from Xenopus eggs. The recombinant Xenopus Wee1 protein efficiently phosphorylates Cdc2 exclusively on Tyr- 15 in a cyclin-dependent manner. The addition of exogenous Wee1 protein to Xenopus cell cycle extracts results in a dose-dependent delay of mitotic initiation that is accompanied by enhanced tyrosine phosphorylation of Cdc2. The activity of the Wee1 protein is highly regulated during the cell cycle: the interphase, underphosphorylated form of Wee1 (68 kDa) phosphorylates Cdc2 very efficiently, whereas the mitotic, hyperphosphorylated version (75 kDa) is weakly active as a Cdc2-specific tyrosine kinase. The down-modulation of Wee1 at mitosis is directly attributable to phosphorylation, since dephosphorylation with protein phosphatase 2A restores its kinase activity. During interphase, the activity of this Wee1 homolog does not vary in response to the presence of unreplicated DNA. The mitosis-specific phosphorylation of Wee1 is due to at least two distinct kinases: the Cdc2 protein and another activity (kinase X) that may correspond to an MPM-2 epitope kinase. These studies indicate that the down-regulation of Wee1-like kinase activity at mitosis is a multistep process that occurs after other biochemical reactions have signaled the successful completion of S phase
Radiographic measurements of the trachea in domestic short haired and Persian cats
Tracheal diameter can be assessed from a thoracic radiograph, with assessment of tracheal diameter in dogs based on ratios between tracheal diameter and a skeletal measurement – however reference ranges are not available for the cat. Tracheal narrowing may cause significant clinical problems, although tracheal hypoplasia in dogs may be clinically silent, and is rarely reported in cats (both mesati- and brachycephalic). The tracheal diameter and trachea:thoracic inlet and trachea:rib ratios were calculated for populations of Domestic Short Haired (DSH) (n=68) and Persian (n=40) cats. This gave reference ranges for radiographic tracheal measurements in these breeds. It is proposed that the tracheal diameter in a normal DSH cat should be 18% of the diameter of the thoracic inlet, and compared to 20% in Persian cats
The Mass Operator in the Light-Cone Representation
I argue that for the case of fermions with nonzero bare mass there is a term
in the matter density operator in the light-cone representation which has been
omitted from previous calculations. The new term provides agreement with
previous results in the equal-time representation for mass perturbation theory
in the massive Schwinger model. For the DLCQ case the physics of the new term
can be represented by an effective operator which acts in the DLCQ subspace,
but the form of the term might be hard to guess and I do not know how to
determine its coefficient from symmetry considerations.Comment: Revtex, 8 page
Use of an audio-paced incremental swimming test in young national-level swimmers
Purpose:To evaluate the reliability and sensitivity to training of an audio-paced incremental swimming test.Methods:Eight young national-level male swimmers (age 15 ± 1 year) performed a 7 × 200-m incremental swimming test (velocities 1.19, 1.24, 1.28, 1.33, 1.39, and 1.45 m/s and maximal sprint pace) using an audio-pacing device. The same test was performed 4 times by each participant, 1 wk apart to assess reliability (WK1, WK2) and after 9 and 20 wk of training (WK9, WK20). Blood lactate concentration ([La−]) and heart rate (HR) were recorded after each stage. Outcome measures were the velocity (v) and HR at lactate markers of 2 mM, 4 mM, and Δ1 mM.Results:Velocities at the lactate markers proved to be more reliable than HR, with typical errors ranging from 0.66% to 2.30% and 1.28% to 4.50%, respectively (shifts in mean ranged –0.91% to 0.73% and –0.84% to 1.79%, respectively). Across WK1, WK9, and WK20 there were significant improvements in peak velocity (P < .001) and each of the velocities associated with the lactate markers (P < .05), whereas only HR at Δ1 mM improved (P < .05).Conclusions:This article demonstrates that an audio-paced incremental swimming test is reliable for use with junior swimmers and is sensitive to changes observed after training. The postswimming measurement of HR in the pool was comparatively less reliable.</jats:sec
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