9,127 research outputs found
Milton Keynes: an outline cost-benefit study
This is a preliminary survey of some of the factors which would need to
be investigated in the design and cost-benefit analysis of alternative
transport systems for Milton Keynes. It outlines the framework within which
further work can be developed and provides some order-of-magnitude estimates
for basic elements in the transport cost-benefit equations
Outcomes of CCAFS Work in Vietnam
The study explored how CCAFS SEA outputs have helped the country achieve its development outcomes in the agricultural sector. The assessment showed that CCAFS SEA, although still on-going, has contributed to specific outcomes in Vietnam, which include changes in knowledge, approaches, practices, and strategies related to climate change, particularly in the agricultural sector. These outcomes were observed among decision makers, policymakers, technical staff, and farmers
A prediction of 3-D viscous flow and performance of the NASA low-speed centrifugal compressor
A prediction of the 3-D turbulent flow in the NASA Low-Speed Centrifugal Compressor Impeller has been made. The calculation was made for the compressor design conditions with the specified uniform tip clearance gap. The predicted performance is significantly worse than that predicted in the NASA design study. This is explained by the high tip leakage flow in the present calculation and by the different model adopted for tip leakage flow mixing. The calculation gives an accumulation for high losses in the shroud/pressure-side quadrant near the exit of the impeller. It also predicts a region of meridional backflow near the shroud wall. Both of these flow features should be extensive enough in the NASA impeller to allow detailed flow measurements, leading to improved flow modelling. Recommendations are made for future flow studies in the NASA impeller
Milton Keynes - preliminary estimates of regional traffic flows in 1981
The Milton Keynes Development Corporation and their planning
consultants have asked the College Transport Group to investigate the
scale of likely regional traffic flows into and out of Milton Keynes.
At this stage the emphasis is on providing information for the preparation
of a Master Plan for the city itself, rather than detailed traffic
estimates for planning transport systems in the surrounding region.
Population estimates for 1981 have been obtained from County
Councils for areas within a 20 mile radius of the new city, and the
proportions attracted to Milton Keynes for work and shopping assessed
using gravity model techniques. Separate estimates have been made of
work journeys from the city to regional employment and to London.
Possible upper and lower limits to these forecasts are included to
account for many uncertainties in the absolute and relative growth of
population, employment and shopping opportunities in the city itself and
in the surrounding region. The results are presented as traffic flews
into and out of octant sectors around the city. Flows to the east are
greater than to the west with work trip flows of the order of 2,500 person
trips each way in the most heavily loaded sectors. A 1981 city population
of 150,000 is likely to produce at least 1,500 daily commuters to London
using the fast rail service, with an additional 200 commuters from the region
using Milton Keynes railway station
High-Precision Calculations in Strongly Coupled Quantum Field Theory with Next-to-Leading-Order Renormalized Hamiltonian Truncation
Hamiltonian Truncation (a.k.a. Truncated Spectrum Approach) is an efficient
numerical technique to solve strongly coupled QFTs in d=2 spacetime dimensions.
Further theoretical developments are needed to increase its accuracy and the
range of applicability. With this goal in mind, here we present a new variant
of Hamiltonian Truncation which exhibits smaller dependence on the UV cutoff
than other existing implementations, and yields more accurate spectra. The key
idea for achieving this consists in integrating out exactly a certain class of
high energy states, which corresponds to performing renormalization at the
cubic order in the interaction strength. We test the new method on the strongly
coupled two-dimensional quartic scalar theory. Our work will also be useful for
the future goal of extending Hamiltonian Truncation to higher dimensions d >=
3.Comment: 8 pages, 4 figures; v2: published versio
NLO Renormalization in the Hamiltonian Truncation
Hamiltonian Truncation (a.k.a. Truncated Spectrum Approach) is a numerical
technique for solving strongly coupled QFTs, in which the full Hilbert space is
truncated to a finite-dimensional low-energy subspace. The accuracy of the
method is limited only by the available computational resources. The
renormalization program improves the accuracy by carefully integrating out the
high-energy states, instead of truncating them away. In this paper we develop
the most accurate ever variant of Hamiltonian Truncation, which implements
renormalization at the cubic order in the interaction strength. The novel idea
is to interpret the renormalization procedure as a result of integrating out
exactly a certain class of high-energy "tail states". We demonstrate the power
of the method with high-accuracy computations in the strongly coupled
two-dimensional quartic scalar theory, and benchmark it against other existing
approaches. Our work will also be useful for the future goal of extending
Hamiltonian Truncation to higher spacetime dimensions.Comment: 28pp + appendices, detailed version of arXiv:1706.0612
The interlaminar fracture toughness of woven graphite/epoxy composites
The interlaminar fracture toughness of 2-D graphite/epoxy woven composites was determined as a function of stacking sequence, thickness, and weave pattern. Plain, oxford, 5-harness satin, and 8-harness satin weaves of T300/934 material were evaluated by the double cantilever beam test. The fabric material had a G (sub Ic) ranging from 2 to 8 times greater than 0 degrees unidirectional T300/934 tape material. The interlaminar fracture toughness of a particular weave style was dependent on whether the stacking sequence was symmetric or asymmetric and, in some cases, on the fabric orientation
Explicit finite-volume time-marching calculations of total temperature distributions in turbulent flow
A method was developed which calculates two-dimensional, transonic, viscous flow in ducts. The finite volume, time-marching formulation is used to obtain steady flow solutions of the Reynolds-averaged form of the Navier-Stokes equations. The entire calculation is performed in the physical domain. This paper investigates the introduction of a new formulation of the energy equation which gives improved transient behavior as the calculation converges. The effect of variable Prandtl number on the temperature distribution through the boundary layer is also investigated. A turbulent boundary layer in an adverse pressure gradient (M = 0.55) is used to demonstrate the improved transient temperature distribution obtained when the new formulation of the energy equation is used. A flat plate turbulent boundary layer with a supersonic free-stream Mach number of 2.8 is used to investigate the effect of Prandtl number on the distribution of properties through the boundary layer. The computed total temperature distribution and recovery factor agree well with the measurements when a variable Prandtl number is used through the boundary layer
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