4,904 research outputs found
On-line measurement of heat of combustion
An experimental method for an on-line measurement of heat of combustion of a gaseous hydrocarbon fuel mixture of unknown composition is developed. It involves combustion of a test gas with a known quantity of air to achieve a predetermined oxygen concentration level in the combustion products. This is accomplished by a feedback controller which maintains the gas volumetric flow rate at a level consistent with the desired oxygen concentration in the products. The heat of combustion is determined from a known correlation with the gas volumetric flow rate. An on-line microcomputer accesses the gas volumetric flow data, and displays the heat of combustion values at desired time intervals
Spectra of phase point operators in odd prime dimensions and the extended Clifford group
We analyse the role of the Extended Clifford group in classifying the spectra
of phase point operators within the framework laid out by Gibbons et al for
setting up Wigner distributions on discrete phase spaces based on finite
fields. To do so we regard the set of all the discrete phase spaces as a
symplectic vector space over the finite field. Auxiliary results include a
derivation of the conjugacy classes of .Comment: Latex, 19page
Aspects of mutually unbiased bases in odd prime power dimensions
We rephrase the Wootters-Fields construction [Ann. Phys., {\bf 191}, 363
(1989)] of a full set of mutually unbiased bases in a complex vector space of
dimensions , where is an odd prime, in terms of the character
vectors of the cyclic group of order . This form may be useful in
explicitly writing down mutually unbiased bases for .Comment: 3 pages, latex, no figure
Quantum phase space distributions in thermofield dynamics
It is shown that the the quantum phase space distributions corresponding to a
density operator can be expressed, in thermofield dynamics, as overlaps
between the state and "thermal" coherent states. The usefulness
of this approach is brought out in the context of a master equation describing
a nonlinear oscillator for which exact expressions for the quantum phase
distributions for an arbitrary initial condition are derived.Comment: 17 pages, revtex, no figures. number of pages were incorrectly stated
as 3 instead of 17. No other correction
Coronary artery disease epidemic in Pakistan: more electrocardiographic evidence of ischaemia in women than in men
Indo-Pakistani populations have one of the highest risks of coronary artery disease (CAD) in the world. A population-based, cross-sectional survey was conducted on 3143 adults aged ⩾40 years from 12 randomly selected communities in Karachi, Pakistan. Apart from smoking, women had more CAD risk factors (diabetes, hypertension, obesity, dyslipidaemia) than men. Definite CAD (history and Q waves on ECG) was more prevalent in men than in women (6.1% vs 4.0%; p = 0.009). In contrast, ischaemic and major ECG changes were twice as prevalent in women as in men (29.4% vs 15.6%, and 21.0% vs 10.5%; p<0.001 for each, respectively). All measures of CAD were strongly predicted by the metabolic syndrome, but that failed to account for the greater prevalence of ECG abnormalities in women than in men. The findings indicate that one in five middle-aged adults in urban Pakistan may have underlying CAD. Women are at greater risk than men
Nuclear deformation and neutrinoless double- decay of Zr, Mo, Ru, Pd, Te and Nd nuclei in mass mechanism
The decay of Zr, Mo,
Ru, Pd, Te and Nd isotopes for the
transition is studied in the Projected Hartree-Fock-Bogoliubov
framework. In our earlier work, the reliability of HFB intrinsic wave functions
participating in the decay of the above mentioned nuclei
has been established by obtaining an overall agreement between the
theoretically calculated spectroscopic properties, namely yrast spectra,
reduced : transition probabilities, quadrupole moments
, gyromagnetic factors as well as half-lives
for the transition and the available
experimental data. In the present work, we study the decay for the transition in the mass mechanism
and extract limits on effective mass of light as well as heavy neutrinos from
the observed half-lives using nuclear
transition matrix elements calculated with the same set of wave functions.
Further, the effect of deformation on the nuclear transition matrix elements
required to study the decay in the mass
mechanism is investigated. It is noticed that the deformation effect on nuclear
transition matrix elements is of approximately same magnitude in and decay.Comment: 15 pages, 1 figur
Cost-effectiveness of community-based strategies for blood pressure control in a low-income developing country: findings from a cluster-randomized, factorial-controlled trial.
BACKGROUND: Evidence on economically efficient strategies to lower blood pressure (BP) from low- and middle-income countries remains scarce. The Control of Blood Pressure and Risk Attenuation (COBRA) trial randomized 1341 hypertensive subjects in 12 randomly selected communities in Karachi, Pakistan, to 3 intervention programs: (1) combined home health education (HHE) plus trained general practitioner (GP); (2) HHE only; and (3) trained GP only. The comparator was no intervention (or usual care). The reduction in BP was most pronounced in the combined group. The present study examined the cost-effectiveness of these strategies. METHODS AND RESULTS: Total costs were assessed at baseline and 2 years to estimate incremental cost-effectiveness ratios based on (1) intervention cost; (2) cost of physician consultation, medications, diagnostics, changes in lifestyle, and productivity loss; and (3) change in systolic BP. Precision of the incremental cost-effectiveness ratio estimates was assessed by 1000 bootstrapping replications. Bayesian probabilistic sensitivity analysis was also performed. The annual costs per participant associated with the combined HHE plus trained GP, HHE alone, and trained GP alone were 3.34, and 23 (95 confidence interval, 6-99) per mm Hg reduction in systolic BP compared with usual care, and remained so in 97.7 of 1000 bootstrapped replications. CONCLUSIONS: The combined intervention of HHE plus trained GP is potentially affordable and more cost-effective for BP control than usual care or either strategy alone in some communities in Pakistan, and possibly other countries in Indochina with similar healthcare infrastructure
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