Possible measurable effects of light propagating in electromagnetized vacuum, as predicted by a scalar tensor theory of gravitation

The effect of static electromagnetic fields on the propagation of light is analyzed in the context of a particular class of scalar-tensor gravitational theories. It is found that for appropriate field configurations and light polarization, anomalous amplitude variations of the light as it propagates in either a magnetized or electrified vacuum are strong enough to be detectable in relatively simple laboratory experiments.Comment: 14 pages, 1 figur

Interpretation of Voltage Measurements in Cutting Torches

Anode-cathode and nozzle-cathode voltages, plenum pressure and gas mass flow measurements in a low current (30 A) cutting torch, operated with oxygen gas, are used as inputs for an electrical model coupled to a simplified fluid model, in order to infer some properties of the plasma-gas structure that are difficult to measure. © 2006 American Institute of Physics.Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Minotti, F.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas

A numerical investigation of the kinetic processes in the initial (nanosecond range) stage of the double-arcing instability was developed. The plasma-sheath boundary region of an oxygen-operated cutting torch was considered. The energy balance and chemistry processes in the discharge were described. It is shown that the double-arcing instability is a sudden transition from a diffuse (glow-like) discharge to a constricted (arc-like) discharge in the plasma-sheath boundary region arising from a field-emission instability. A critical electric field value of ∼10^7 V/m was found at the cathodic part of the nozzle wall under the conditions considered. The field-emission instability drives in turn a fast electronic-to-translational energy relaxation mechanism, giving rise to a very fast gas heating rate of at least ∼10^9 K/s, mainly due to reactions of preliminary dissociation of oxygen molecules via the highly excited electronic state O2(B^3) populated by electron impact. It is expected that this fast oxygen heating rate further stimulates the discharge contraction through the thermal instability mechanism.Fil: Mancinelli, Beatriz Rosa. Universidad Tecnológica Nacional. Facultad Regional Venado Tuerto; ArgentinaFil: Prevosto, Leandro. Universidad Tecnológica Nacional. Facultad Regional Venado Tuerto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Chamorro Garcés, Juan Camilo. Universidad Tecnológica Nacional. Facultad Regional Venado Tuerto; ArgentinaFil: Minotti, Fernando Oscar. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kelly, Hector Juan. Universidad Tecnológica Nacional. Facultad Regional Venado Tuerto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Early diagnosis of acute coronary syndrome.

The diagnostic evaluation of acute chest pain has been augmented in recent years by advances in the sensitivity and precision of cardiac troponin assays, new biomarkers, improvements in imaging modalities, and release of new clinical decision algorithms. This progress has enabled physicians to diagnose or rule-out acute myocardial infarction earlier after the initial patient presentation, usually in emergency department settings, which may facilitate prompt initiation of evidence-based treatments, investigation of alternative diagnoses for chest pain, or discharge, and permit better utilization of healthcare resources. A non-trivial proportion of patients fall in an indeterminate category according to rule-out algorithms, and minimal evidence-based guidance exists for the optimal evaluation, monitoring, and treatment of these patients. The Cardiovascular Round Table of the ESC proposes approaches for the optimal application of early strategies in clinical practice to improve patient care following the review of recent advances in the early diagnosis of acute coronary syndrome. The following specific 'indeterminate' patient categories were considered: (i) patients with symptoms and high-sensitivity cardiac troponin 99th percentile but without dynamic change; and (iv) patients with symptoms and high-sensitivity troponin >99th percentile and dynamic change but without coronary plaque rupture/erosion/dissection. Definitive evidence is currently lacking to manage these patients whose early diagnosis is 'indeterminate' and these areas of uncertainty should be assigned a high priority for research

Selenium uptake and associated anti-oxidant properties in Pleurotus fossulatus cultivated on wheat straw from seleniferous fields

The present study was carried out to examine the antioxidant activity in oyster mushroom cultivated on selenium (Se) rich substrate. Pleurotus fossulatus was cultivated on Se-rich wheat straw collected from the seleniferous belt of Punjab (India) and its potential to accumulate Se from substrate was examined. Using different assay systems the modulations in the anti-oxidant profile of Se enriched mushroom was studied in comparison to the mushrooms cultivated on normal straw. The oyster mushrooms were observed to potentially mobilize Se from Se-rich substrates to fruiting bodies, resulting in significantly high uptake (37.2±0.6 μg g−1) as compared to control (3.57±0.53 mg g−1). The antioxidant activity, as determined by various assays, such as reducing power, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, and metal chelating activity, was higher in the experimental mushrooms when compared to control. The results obtained demonstrate that Se-fortified mushrooms through cultivation on straw containing organic forms of Se can be considered as natural and effective dietary supplements of organic Se for humans. The present study proposes the use of Se-rich agricultural residues as substrates for mushroom cultivation for human and livestock supplementation