185,171 research outputs found
Method for determining thermo-physical properties of specimens
The square root of the product of thermophysical properties q, c and k, where p is density, c is specific heat and k is thermal conductivity, is determined directly on a test specimen such as a wind tunnel model. The test specimen and a reference specimen of known specific heat are positioned at a given distance from a heat source. The specimens are provided with a coating, such as a phase change coating, to visually indicate that a given temperature was reached. A shutter interposed between the heat source and the specimens is opened and a motion picture camera is actuated to provide a time record of the heating step. The temperature of the reference specimen is recorded as a function of time. The heat rate to which both the test and reference specimens were subjected is determined from the temperature time response of the reference specimen by the conventional thin-skin calorimeter equation
Forward bearing reactor mechanism for Titan 3-E/Centaur D-1T space launch vehicle
System between the Titan/Centaur launch vehicle and its aerodynamic shroud is described. The system provides a precise spring constant and is capable of being inactivated during flight. Design requirements, design details, and the test program are discussed. The conventional English system of units was used during this development program for all principal measurements and calculations
Flow field simulation Patent
Wind tunnel method for simulating flow fields around blunt vehicles entering planetary atmospheres without involving high temperature
New method for determining thermophysical properties of test specimens
Model can be tested directly, which eliminates costly, time-consuming, and inaccurate method of making test models solely for purpose of determining thermophysical properties. Method is adaptable to numerous modifications and variations
Heavy Rainfall Warning Assessment Tool User Guide. Version 1.2
This report is a User Guide to a PC tool for assessing Heavy Rainfall Warnings. Development of the PC tool formed an important operational output of the Environment Agency and Met Office funded project: "Development of Rainfall Forecast Performance Monitoring Criteria. Phase 1: Development of Methodology and Algorithms" (Jones et al., 2003).
The Heavy Rainfall Warning (HRW) Assessment Tool is a toolkit for Microsoft Excel. The tool allows the user to configure an assessment framework for a particular format of Heavy Rainfall Warning, enter and save data for forecasts and ground-truths, and generate a range of performance measures and other statistics for new and previously saved data. Summary tables are presented using Excel's PivotTable feature, from which charts can also be generated.
Performance measures are provided to assess forecasts of heavy rainfall in continuous variable, categorical and probability form: these include bias, rmse, R-squared Efficiency, skill scores and the Continuous Brier Score
Active Gel Model of Amoeboid Cell Motility
We develop a model of amoeboid cell motility based on active gel theory.
Modeling the motile apparatus of a eukaryotic cell as a confined layer of
finite length of poroelastic active gel permeated by a solvent, we first show
that, due to active stress and gel turnover, an initially static and
homogeneous layer can undergo a contractile-type instability to a polarized
moving state in which the rear is enriched in gel polymer. This agrees
qualitatively with motile cells containing an actomyosin-rich uropod at their
rear. We find that the gel layer settles into a steadily moving, inhomogeneous
state at long times, sustained by a balance between contractility and filament
turnover. In addition, our model predicts an optimal value of the
gel-susbstrate adhesion leading to maximum layer speed, in agreement with cell
motility assays. The model may be relevant to motility of cells translocating
in complex, confining environments that can be mimicked experimentally by cell
migration through microchannels.Comment: To appear in New Journal of Physic
Climate resilience in the United Kingdom wine production sector: CREWS-UK
As cool climate viticulture rapidly expands, the England and Wales wine sector is winning international acclaim, particularly for its sparkling wines, and is attracting significant investment. Supported by warming climate trends during the growing season, wine producers are establishing new vineyards planted predominantly with Pinot Noir and Chardonnay. Grape-friendly weather conditions in 2018 led to a record harvest and may be a sign of good things to come. Long term (100-years) Growing Season Average Temperatures (GSTs) in south-east and south-central England have noticeably increased with 6 of the top 10 warmest growing seasons (April–October), over the last 100 years, occurring since 2005. However, weather and growing season conditions fluctuate markedly from year to year, meaning that yields and grape quality continue to vary significantly. Weather extremes are anticipated to become more frequent under future climate change, further threatening the stability of production. Current uncertainty over future climatic conditions during the growing season and their potential effects on viticulture in the UK exposes both existing producers and potential investors to unquantified risks and opportunities. The CREWS-UK climate resilience research project is generating actionable information on how climate change may affect the wine production sector, to support better decision-making and investment
Vibrational transfer functions for complex structures
Evaluation of effects of vibrational multiple frequency forcing functions is discussed. Computer program for developing vibrational transfer functions is described. Possible applications of computer program are enumerated
Entanglement entropy and differential entropy for massive flavors
In this paper we compute the holographic entanglement entropy for massive
flavors in the D3-D7 system, for arbitrary mass and various entangling region
geometries. We show that the universal terms in the entanglement entropy
exactly match those computed in the dual theory using conformal perturbation
theory. We derive holographically the universal terms in the entanglement
entropy for a CFT perturbed by a relevant operator, up to second order in the
coupling; our results are valid for any entangling region geometry. We present
a new method for computing the entanglement entropy of any top-down brane probe
system using Kaluza-Klein holography and illustrate our results with massive
flavors at finite density. Finally we discuss the differential entropy for
brane probe systems, emphasising that the differential entropy captures only
the effective lower-dimensional Einstein metric rather than the ten-dimensional
geometry.Comment: 54 pages, 8 figures; v2 references and comments adde
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