46,107 research outputs found
The experimental determination of tyre model parameters
SUMMARY
This report describes the analysis of a series of experiments on pneumatic tyres
which were designed to test the various hypotheses: regarding the deformed shape of a
tyre during the steering process.
The experiments consisted of several separate tests first described in Ref. 1 and 2.
a) The application of a point lateral force or a moment at one position on the tread band
which is restrained at the centre of the wheel, and the measurement of the resulting
lateral deflection of each point of the tyre perimeter.
b) The application of a uniform force around the tyre perimeter on a hollow cylindrical
former and applying a load at the centre of the wheel.
c) Direct determination of tread band tension by cutting the tread band and bridging the
cut by a dynamometer.
d) Estimation of the bending modulus of the tread band by test on sections cut from the
tread band.
The analysis of the experiments is carried out by first transforming the test results
into a Fourier series and determining the spectral content of the bending line with an
harmonic analysis. Transfer functions of beam and string models are derived and applied
to the test results. A method of considering a three parameter model is described
Pain management following new and long-standing spinal cord injury: A pilot study of changes in pain intensity experienced during the day
The aim of the study was to examine variations in pain intensity during the day experienced by patients with spinal cord injury. Fourteen consecutive patients had clinical and demographic data recorded. Pain intensity was recorded using a Graphic Rating Scale (GRS) at 2-3-h intervals. Patients were grouped according to maximum GRS into mild and severe groups at assessment (T0). Changes of one-third in GRS were deemed clinically significant. Eight men and six women (mean age 53.1; SD 16.5; range 28-75) were studied. Seven patients with mild pain tended to deteriorate and those with severe pain to improve. Eight patients demonstrated clinically significant changes. These findings suggest inadequate pain control early morning for one group and increasing pain during the day for another. Use of such simple scores over time would enhance pain rehabilitation for all spinal cord injury patients. Usual GRS reporting may mask clinically significant, treatable, changes in pain
Biology, Injury, and Control of the European Needle-bending Midge (Diptera: Cecidomyiidae) on Scotch Pine in Michigan
Contarinia baeri is univoltine in Michigan. Adults emerge in spring, and females deposit eggs in small clusters in the sheaths of new-growth pine needles. Larvae hatch shortly thereafter and there are three larval instars. Larval feeding causes the needles to at first droop, discolor, and eventually drop, reducing the quality of Christmas trees and occasionally killing shoots. Larvae overwinter on the ground in cocoons, and pupate in spring. Adults were suppressed (\u3e 75% control) with formulations of Pydrin® (fenvalerate) and Tempo® (cyfluthrin) applied within a week after adult emergence
A Split-Stem Lesion on Young Hybrid \u3ci\u3ePopulus\u3c/i\u3e Trees Caused by the Tarnished Plant Bug, \u3ci\u3eLygus Lineolaris\u3c/i\u3e (Hemiptera: [Heteroptera]: Miridae)
The tarnished plant bug, known principally as an agricultural pest, injures young hybrid Populus by feeding on the stems and meristems. Tarnished plant bug eggs, fungi associated with some lesions, and simple mechanical stimuli alone from feeding appeared not to cause lesion formation. Of 20 Populus hybrids tested in a clonal trial, four appeared to be consistently susceptible to lesion injury, with Populus nigra var. betulifolia x trichocarpa the most susceptible. Several clones showed high resistance in the trial but a few were susceptible in other plantings and in host preference tests when caged with tarnished plant bugs. Lesions diminished tenfold on Populus where horseweed, the insect\u27s principal wild host, grew along with susceptible poplars. The tarnished plant bug can be suppressed by ultra-low volume pesticides and cultural manipulation of understory vegetation
Glioblastoma in the elderly - how do we choose who to treat?
Objective:
Glioblastoma (GBM) is the commonest primary malignant brain tumour amongst the adult population. Incidence peaks in the 7th and 8th decades of life and as our global population ages, rates are increasing. GBM is an almost universally fatal disease with life expectancy in the range of 3–5 months amongst the elderly.
Materials and Methods:
The assessment of elderly GBM patients prior to treatment decisions is poorly researched and unstandardised. In order to begin tackling this issue we performed a cross-sectional survey across all UK based consultant neuro-oncologists to review their current practice in assessing elderly GBM patients.
Results:
There were 56 respondents from a total of 93 recipients (60% response rate). All respondents confirmed that at least some patients aged 70 or over were referred to their clinics from the local multidisciplinary team meeting (MDT). Only 18% of consultants routinely performed a cognitive or frailty screening test at initial consultation. Of those who performed a screening test, the majority reported that the results of the test changed their treatment decision in approximately 50% of cases. Participants ranked performance status as the most important factor in determining treatment decisions.
Conclusions:
Considering the heterogeneity of this patient population, we argue that performance status is a crude measure of vulnerability within this cohort. Elderly GBM patients represent a unique clinical scenario because of the complexity of distinguishing neuro-oncology related symptoms from general frailty. There is a need for specific geriatric assessment models tailored to the elderly neuro-oncology population in order to facilitate treatment decisions
The Impact of Tobacco Control Program Expenditures on Aggregate Cigarette Sales: 1981-1998
Since the 1998 Master Settlement Agreement between states and the tobacco industry, states have unprecedented resources for programs to reduce tobacco use. Decisions concerning the use of these funds will, in part, be based on the experiences of states with existing programs. We review the experiences of several states that have adopted comprehensive tobacco control programs. We also report estimates from econometric analyses of the impact of tobacco control expenditures on aggregate tobacco use in all states and in selected states with comprehensive programs for the period from 1981 through 1998. Our analyses clearly show that increases in funding for state tobacco control programs reduce tobacco use.
Dominant two-loop electroweak corrections to the hadroproduction of a pseudoscalar Higgs boson and its photonic decay
We present the dominant two-loop electroweak corrections to the partial decay
widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A^0,
with mass M_{A^0} < 2 M_W, in the two-Higgs-doublet model for low to
intermediate values of the ratio tan(beta) = v_2/v_1 of the vacuum expectation
values. They apply as they stand to the production cross sections in hadronic
and two-photon collisions, at the Tevatron, the LHC, and a future photon
collider. The appearance of three gamma_5 matrices in closed fermion loops
requires special care in the dimensional regularization of ultraviolet
divergences. The corrections are negative and amount to several percent, so
that they fully compensate or partly screen the enhancement due to QCD
corrections.Comment: 9 pages, 3 figure
A symmetry adapted approach to vibrational excitations in atomic clusters
An algebraic method especially suited to describe strongly anharmonic
vibrational spectra in molecules may be an appropriate framework to study
vibrational spectra of Na clusters, where nearly flat potential energy
surfaces and the appearance of close lying isomers have been reported. As an
illustration we describe the model and apply it to the Be, H, Be
and Na clusters.Comment: 8 pages with 2 tables, invited talk at `Atomic Nuclei & Metallic
Clusters: Finite Many-Fermion Systems', Prague, Czech Republic, September
1-5, 199
Comment on ``Boson-realization model for the vibrational spectra of tetrahedral molecules''
An algebraic model in terms of a local harmonic boson realization was
recently proposed to study molecular vibrational spectra [Zhong-Qi Ma et al.,
Phys. Rev. A 53, 2173 (1996)]. Because of the local nature of the bosons the
model has to deal with spurious degrees of freedom. An approach to eliminate
the latter from both the Hamiltonian and the basis was suggested. We show that
this procedure does not remove all spurious components from the Hamiltonian and
leads to a restricted set of interactions. We then propose a scheme in which
the physical Hamiltonian can be systematically constructed up to any order
without the need of imposing conditions on its matrix elements. In addition, we
show that this scheme corresponds to the harmonic limit of a symmetry adapted
algebraic approach based on U(2) algebras.Comment: 9 pages Revtex, submitted February 199
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