1,014 research outputs found
Modified NASA-Lewis chemical equilibrium code for MHD applications
A substantially modified version of the NASA-Lewis Chemical Equilibrium Code was recently developed. The modifications were designed to extend the power and convenience of the Code as a tool for performing combustor analysis for MHD systems studies. The effect of the programming details is described from a user point of view
Introduction to The Special Issue: Advances in Methods and Measurement in Family Psychology
This special issue presents a collection of reports that highlight recent advances in methods and measurement and also shed light on the complexity of family psychology. The importance of theory in guiding solid family science is evident throughout these reports. The reports include guides for researchers who incorporate direct observation into their research protocols and the ever-expanding field of tele-health interventions. Advanced analytic approaches are offered in the areas of grid sequence analysis, latent fixed-effects models, and the Factors of Curves Model (FOCUS). These sophisticated analytic approaches may be applied to advance systemic thinking in family psychology. The last set of articles illustrate how complex and innovative methodologies are applied to address important societal issues. Work experiences and marital relationships in African American couples address the importance of spillover effects in contemporary families. The creation of biobehavioral plasticity index has the potential to inform gene x environment contributions to family functioning. Finally, the unique methodological issues that are particularly germane to the diverse nature of stepfamilies and nonresident fathers are addressed. We hope that readers of this special issue will return to these reports as resources and examples of theory-driven methods and measurements
EFFECT OF SMOKING ON HEART RATE VARIABILITY IN NORMAL HEALTHY VOLUNTEERS
ABSTRACTObjective: The aim of this study is to determine the effect of tobacco smoke on heart rate variability (HRV).Methods: This study included 90 male smokers (30-mild, 30-moderate, 30-severe) (Group II) and 30 age-matched non-smokers as controls (Group I).HRV analysis was performed using 8 channels Physiopac of Medicaid Company. All the subjects were subjected to HRV test. The short-term 8 minutesHR recording was performed for HRV analysis.Results: Mean RR, mean HR, root mean square of the successive differences, of the smokers and non-smokers, did not differ significantly. However,smokers NN50, Pnn50, high frequency (HF) declined significantly, and the smokers show significantly higher low frequency (LF), LF/HF ratio whencompared with those of the non-smoking individuals (p<0.05).Conclusion: HRV analysis of smokers and nonsmokers showed that smoking subjects had an autonomic imbalance suggestive of an increasedsympathetic tone or decreased parasympathetic tone. Sympathetic overactivity may lead to cardiovascular disease development in smokers.Keywords: Smoking, Healthy volunteers, Heart rate variability
Behaviour of surface-active substances at the dropping mercury electrode
It is found that the differential capacity of the dropping mercury electrode is affected mainly in two ways by added surface-active substances. At about the electrocapillary zero there is a strong lowering of the capacity due to adsorption of surface-active substances. At some higher cathodic potential there is enormous increase in differential capacity leading to a maximum and is followed by a sharp fall in the capacity; the latter is due to the desorption taking place more or less sharply at the higher cathodic potentials. The theory of the phenomenon has been formulated
Effect of electric field on Tyndall scattering
The study of the action of an electric field on the scattering intensity of sols has thus led to interesting results. The study is useful in determining the shape of the particles. The present technique would be supplementary to the studies of double refraction, in that the latter cannot be conveniently investigated in a highly scattering system. With slightly conducting sols, large fields can be used so as to produce saturation effects. Under such conditions, the use of rotating fields would bring about a unique orientation of the discs. A superposition of two A.C. fields of different cycles at right angles to each other would have the same effect as the circular field. The use of elliptical fields would reveal any want of equality of the two axes in the plane of discs of flat particles. The technique itself is simpler than the flow technique. Since there is often a large difference in the dielectric constant between the particles and the medium, the orientation is marked even with small fields, and the electric field is thus more powerful than the magnetic field in bringing about orientation
Efficiency of wetting agents
The relative efficiencies of some of the common wetting agents have been determined by measuring the surface tension of five-minute-old surfaces of the solutions using the ring method in a modified form. Aqueous solutions giving a surface tension of 37 dynes per cm. may be considered to have good wetting properties. It is found that wetting power is not necessarily associated with detergent and emulsifying properties. Salts greatly increase wetting power. Bivalent cations are more effective than univalent cations in increasing wetting power. A moderate degree of hardness in water employed in preparing solutions of wetting agents may be of advantage in the textile industry. The maximum bubble pressure method is shown to be unsuitable for the measurement of surface tension of solutions which show a variation with time. A rough idea of the order of wetting efficiencies of wetting agents can however be obtained by measuring the surface tension of a five-second-old surface by this method
Fragment Flow and the Nuclear Equation of State
We use the Boltzmann-Uehling-Uhlenbeck model with a momentum-dependent
nuclear mean field to simulate the dynamical evolution of heavy ion collisions.
We re-examine the azimuthal anisotropy observable, proposed as sensitive to the
equation of state of nuclear matter. We obtain that this sensitivity is maximal
when the azimuthal anisotropy is calculated for nuclear composite fragments, in
agreement with some previous calculations. As a test case we concentrate on
semi-central collisions at 400 MeV.Comment: 12 pages, ReVTeX 3.0. 12 Postscript figures, uuencoded and appende
Spreading of casein and derivatives
1. Casein has been spread from its aqueous solutions by different methods and it has been found that the modified band method is the most suitable for the study of protein films. 2. Effect of salts on the spreading of casein has been studied. The results obtained can be explained on the basis that two different factors, solubility and the electric charge of the protein molecule influence spreading. 3. Treatment of the protein with formaldehyde causes a decrease in spreading. Change in pH affects spreading of formolised casein to a smaller degree. 4. Sodium metaphosphate diminishes markedly the spreading of casein. Trichloracetic acid, however, has no effect. 5. Deaminisation of casein alters the spreading properties and gives unstable films on acidulated water. No films can be got on distilled water. 6. The spreading properties of an isodisperse fraction of casein have been studied. The limiting area of this fraction has been found to be of the same order as that of the original material
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