4,727 research outputs found
Cycling & Urban Commuting: Results of Behavioural Mode and Route Choice Models
The research reported here was undertaken as part of an Economic and Social Research Council Project (R000237103) entitled Cycling and Urban Mode Choice. The scope of the study is entirely commuting within an urban context. The objectives of the study were:
• to better understand the interactions between car, bus, cycle and walk in an urban context and to explain observed variations in cycle trip rates across towns.
• to be able to forecast the effect of a range of improvements to cycling facilities on mode choice
• to use the estimated models to evaluate some actual schemes
• to provide end users (eg consultants, local authorities, cycling organisations) with a tool to determine the effect of policy measures. In particular, to create models which will enhance the performance of strategic, integrated transport studies. The objectives of this paper are:
• to describe the methodology that was used to examine cycling within an urban mode choice context
• to outline the collection of data required to estimate behavioural models
• to report the results of the estimated mode and route choice models
• to provide illustrations of how the model can be used to appraise improvements to cycle facilities and cycling conditions.
The structure of this paper is as follows. Section 2 gives a brief overview of the policy context of work on cycling in the UK and previous work in the area. Section 3 describes the methodology used to collect the Revealed Preference (RP) and Stated Preference (SP) data necessary for the model. Section 4 describes the data that was collected. Section 5 gives details of the development of the model and some empirical results from the model that was developed. Section 6 illustrates how the model could be used to appraise improvements in cycle facilities and cycling conditions. Section 7 draws some conclusions from the work
Elastic and inelastic breakup of deuterons with energy below 100 MeV
We present calculations of deuteron elastic and inelastic breakup cross
sections and angular distributions at deuteron energies below 100 MeV obtained
using the post-form DWBA approximation. The elastic breakup cross section was
extensively studied in the past. Very few calculations of inelastic breakup
have been performed, however. We also analyze the angular momentum - energy
distributions of the cross section for formation of the compound nucleus after
inelastic breakup.Comment: 7 page
Excitation and emission spectra of rubidium in rare-gas thin-films
To understand the optical properties of atoms in solid state matrices, the
absorption, excitation and emission spectra of rubidium doped thin-films of
argon, krypton and xenon were investigated in detail. A two-dimensional
spectral analysis extends earlier reports on the excitation and emission
properties of rubidium in rare-gas hosts. We found that the doped crystals of
krypton and xenon exhibit a simple absorption-emission relation, whereas
rubidium in argon showed more complicated spectral structures. Our sample
preparation employed in the present work yielded different results for the Ar
crystal, but our peak positions were consistent with the prediction based on
the linear extrapolation of Xe and Kr data. We also observed a bleaching
behavior in rubidium excitation spectra, which suggests a population transfer
from one to another spectral feature due to hole-burning. The observed optical
response implies that rubidium in rare-gas thin-films is detectable with
extremely high sensitivity, possibly down to a single atom level, in low
concentration samples.Comment: 7 pages, 5 figure
Photo-emission rate of sQGP at finite density
We calculate the thermal spectral function of SYM plasma with finite density
using holographic technique. We take the RN-AdS black hole as the dual gravity
theory. In the presence of charge, vector modes of gravitational and
electromagnetic perturbation are coupled with each other. By introducing master
variables for these modes, we solve the coupled system and calculate spectral
function. We also calculated photoemission rate of SYM plasma from spectral
function for light like momentum, AC conductivity and their density dependence.
The suppression of the conductivity in high density is noticed, which might be
yet another mechanism for the Jet quenching phenomena in RHIC experiment.Comment: 27 pages, 10 figure
Threshold corrections to the radiative breaking of electroweak symmetry and neutralino dark matter in supersymmetric seesaw model
We study the radiative electroweak symmetry breaking and the relic abundance
of neutralino dark matter in the supersymmetric type I seesaw model. In this
model, there exist threshold corrections to Higgs bilinear terms coming from
heavy singlet sneutrino loops, which make the soft supersymmetry breaking (SSB)
mass for up-type Higgs shift at the seesaw scale and thus a minimization
condition for the Higgs potential is affected. We show that the required
fine-tuning between the Higgsino mass parameter mu and the SSB mass for up-type
Higgs may be reduced at the electroweak scale, due to the threshold
corrections. We also present how the parameter mu depends on the SSB
B-parameter for heavy singlet sneutrinos. Since the property of neutralino dark
matter is quite sensitive to the size of mu, we discuss how the relic abundance
of neutralino dark matter is affected by the SSB B-parameter. Taking the SSB
B-parameter of order of a few hundreds TeV, the required relic abundance of
neutralino dark matter can be correctly achieved. In this case, dark matter is
a mixture of bino and Higgsino, under the condition that gaugino masses are
universal at the grand unification scale.Comment: 27 pages, 3 figures; references added, discussion about RGEs added,
the version published on PR
Control of Alternaria alternata, Causal Agent of Dead (Dormant) Flower Bud Disease of Pear
Dead (dormant) flower buds of pear are an important phenomenon in pear production in the Netherlands. Vigourous or unbalanced tree growth and Pseudomonas syringae pv. syringae (P.s.s.) are mentioned as likely causes of dead flower buds. Pseudomonas syringae pv. syringae was occasionally isolated from diseased flower buds. However, Alternaria alternata was nearly always isolated from diseased buds and also often in symptomless flower buds. By identifying the causal agent of dead flower buds disease, an effective control strategy can be developed. In field trials it was proven that fungicide treatments can reduce disease incidences significantly
Possible Deviation from the Tri-bimaximal Neutrino Mixing in a Seesaw Model
We propose a simple but suggestive seesaw model with two phenomenological
conjectures: three heavy (right-handed) Majorana neutrinos are degenerate in
mass in the symmetry limit and three light Majorana neutrinos have the
tri-bimaximal mixing pattern . We show that a small mass splitting
between the first generation and the other two generations of heavy Majorana
neutrinos is responsible for the deviation of the solar neutrino mixing angle
from its initial value given by , and the
slight breaking of the mass degeneracy between the second and third generations
of heavy Majorana neutrinos results in a small mixing angle
and a tiny departure of the atmospheric neutrino mixing angle
from . It turns out that a normal hierarchy of the light neutrino
mass spectrum is favored in this seesaw scenario.Comment: RevTex 12 pages (2 EPS figures included). More discussions and
references adde
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