13,503 research outputs found
Noise measurements at Stockton Airport obtained during engineering evaluation of two-segment approaches in a 727-222 aircraft
The results of acoustic measurements made on a 727-222 aircraft during standard ILS and two-segment approaches are presented. The aircraft was equipped with a special purpose glide slope computer to provide the capability of making two-segment noise abatement approaches. For upper segment computations, the computer used barometric-corrected pressure altitude and the slant range to a DME transmitter which was colocated with the glide slope transmitter. The computer used the ILS glide slope deviation for lower segment computations. Additional measurements were made on 737 revenue aircraft using the Stockton Airport. The purpose of the acoustical portion of the test was to measure and identify the noise levels during the various approaches
Noise measurements taken at LAX during operational evaluation of two-segment approaches in a 727-200 aircraft
A series of seven noise measurements were made each day over a period of fifteen days. The first and last flights each day were made by a specially instrumented 727-200 aircraft being used to evaluate the operational effectiveness of two-segment noise abatement approaches in scheduled service. Noise measurements were made to determine the noise reduction benefits of the two-segment approaches
Experimental investigation of the cornering characteristics of 18 by 5.5, type 7, aircraft tires with different tread patterns
The characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 12 deg and at ground speeds from approximately 5 to 90 knots. The results indicate that a tread pattern with pinholes in the ribs reduces the tire cornering capability at high yaw angles on a damp surface but improves cornering on a dry surface. A tread pattern which has transverse grooves across the entire width of the tread improves the tire cornering performance slightly at high speeds on the flooded runway surface. The cornering capability of all the tires is degraded at high ground speeds by thin film lubrication and/or tire hydroplaning effects. Alterations to the conventional tread pattern provide only marginal improvements in the tire cornering capability which suggests that runway surface treatments may be a more effective way of improving aircraft ground performance during wet operations
Constraints on the active tectonics of the Friuli/NW Slovenia area from CGPS measurements and three-dimensional kinematic modeling
We use site velocities from continuous GPS (CGPS) observations and kinematic
modeling to investigate the active tectonics of the Friuli/NW Slovenia area. Data from 42
CGPS stations around the Adriatic indicate an oblique collision, with southern Friuli
moving NNW toward northern Friuli at the relative speed of 1.6 to 2.2 mm/a. We
investigate the active tectonics using 3DMove, a three-dimensional kinematic model tool.
The model consists of one indenter-shaped fault plane that approximates the Adriatic
plate boundary. Using the ‘‘fault-parallel flow’’ deformation algorithm, we move the
hanging wall along the fault plane in the direction indicated by the GPS velocities. The
resulting strain field is used for structural interpretation. We identify a pattern of
coincident strain maxima and high vorticity that correlates well with groups of
hypocenters of major earthquakes (including their aftershocks) and indicates the
orientation of secondary, active faults. The pattern reveals structures both parallel and
perpendicular to the strike of the primary fault. In the eastern sector, which shows more
complex tectonics, these two sets of faults probably form an interacting strike-slip
system
The Early Career of Edwin T. Jenckes: A Florida Pioneer of the 1830’s
A leader of the eastern faction in early state politics was Edwin T. Jenckes, known to his adversaries as “‘the fat man of Florida.” Jenckes was a delegate to the St. Joseph Constitutional Convention of 1838-39 and apparently commanded a large following, for he was designated chairman of two committees. According to the opposition press, he weighed 450 to 500 pounds and was “the greatest” man at the convention. It was alleged that he “retained in his own person, all the management, tact, industry and talent of the whole eastern delegation” and that he, himself, voted five proxies. In case of “any little splitting” between the middle and the western delegations, Jenckes’ “aye or nay, which reverberated through the halls like hoarse thunder, gave law to the whole body. . . .“ 1 Despite the palpable exaggeration of these charges, it is clear that Jenckes was a power in the politics of the period; from the Constitutional Convention, he went on to a career in the State Legislature
Towards Expressive and Versatile Visualization-as-a-Service (VaaS)
The rapid growth of data in scientific visualization has posed significant challenges to the scalability and availability of interactive visualization tools. These challenges can be largely attributed to the limitations of traditional monolithic applications in handling large datasets and accommodating multiple users or devices. To address these issues, the Visualization-as-a-Service (VaaS) architecture has emerged as a promising solution. VaaS leverages cloud-based visualization capabilities to provide on-demand and cost-effective interactive visualization. Existing VaaS has been simplistic by design with focuses on task-parallelism with single-user-per-device tasks for predetermined visualizations. This dissertation aims to extend the capabilities of VaaS by exploring data-parallel visualization services with multi-device support and hypothesis-driven explorations. By incorporating stateful information and enabling dynamic computation, VaaS\u27 performance and flexibility for various real-world applications is improved. This dissertation explores the history of monolithic and VaaS architectures, the design and implementations of 3 new VaaS applications, and a final exploration of the future of VaaS. This research contributes to the advancement of interactive scientific visualization, addressing the challenges posed by large datasets and remote collaboration scenarios
Bioactive composites for bone tissue engineering
One of the major challenges of bone tissue engineering is the production of a suitable scaffold material. In this review the current composite materials options available are considered covering both the methods of both production and assessing the scaffolds. A range of production routes have been investigated ranging from the use of porogens to produce the porosity through to controlled deposition methods. The testing regimes have included mechanical testing of the materials produced through to in vivo testing of the scaffolds. While the ideal scaffold material has not yet been produced, progress is being made
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