Controlling the partial coalescence of a droplet on a vertically vibrated bath

A new method is proposed to stop the cascade of partial coalescences of a droplet laid on a liquid bath. The strategy consists in vibrating the bath in the vertical direction in order to keep small droplets bouncing. Since large droplets are not able to bounce, they partially coalesce until they reach a critical size. The system behaves as a low pass filter : droplets smaller than the critical size are selected. This size has been investigated as a function of the acceleration and the frequency of the bath vibration. Results suggest that the limit size for bouncing is related to the first mode of the droplet deformation.Comment: 4 pages, 3 figures, accepted in Phys. Rev.

Asymmetry-Driven Structure Formation in Pair Plasmas

The nonlinear propagation of electromagnetic waves in pair plasmas, in which the electrostatic potential plays a very important but subdominant role of a "binding glue" is investigated. Several mechanisms for structure formation are investigated, in particular, the "asymmetry" in the initial temperatures of the constituent species. It is shown that the temperature asymmetry leads to a (localizing) nonlinearity that is new and qualitatively different from the ones originating in ambient mass or density difference. The temperature asymmetry driven focusing-defocusing nonlinearity supports stable localized wave structures in 1-3 dimensions, which, for certain parameters, may have flat-top shapes.Comment: 23 pages, 6 figures, introduction revised, edited typos, accepted for publication in Phys. Rev.

Vortex Bubble Formation in Pair Plasmas

It is shown that delocalized vortex solitons in relativistic pair plasmas with small temperature asymmetries can be unstable for intermediate intensities of the background electromagnetic field. Instability leads to the generation of ever-expanding cavitating bubbles in which the electromagnetic fields are zero. The existence of such electromagnetic bubbles is demonstrated by qualitative arguments based on a hydrodynamic analogy, and by numerical solutions of the appropriate Nonlinear Schr\"odinger equation with a saturating nonlinearity.Comment: 4 pages of two-column text, 2 figure

Thyroid disorders in antenatal women in a rural hospital in central India

Background: Thyroid disorders are one of the most common endocrine disorders in pregnancy. Thyroid disorders are known to be associated with abnormal maternal and fetal outcomes and are often overlooked in pregnant women because of nonspecific symptoms and hypermetabolic state of pregnancy.Methods: 514 women between 12 to 18 weeks of pregnancy from October 2013 to September 2015were recruited in the study. Serum thyroid-stimulating hormone (TSH) testing was done. Free T4 and free T3 were tested in subjects with a deranged TSH value. Subjects were followed up till delivery, and maternal and fetal complications arising out of thyroid dysfunction were studied.Results: The occurrence of subclinical hypothyroidism was 9.54%, overt hypothyroidism was 2.34% and hyperthyroidism was 0.58%.  When compared to subjects with euthyroidism, anemia and preterm delivery were the most significant maternal complications in subjects with hypothyroidism (p=0.0001 and 0.0001, respectively) whereas miscarriage, IUD/stillbirth, LBW and intrauterine growth restriction were significant fetal complications observed in subjects with hypothyroidism, with p<0.0001, p=0.002, 0.025, 0.009 respectively. NICU admissions were 2.58 times more in subjects with thyroid disorders as compared to euthyroid subjects.Conclusions: The occurrence of thyroid disorders was high in our study with associated adverse maternal and fetal outcomes. Routine screening for thyroid dysfunction is recommended to prevent adverse fetal and maternal outcomes. Serum TSH is a sufficient and cost-effective screening tool.

Chronomodulated rupturable pulsatile drug delivery of theophylline: preparation and in vitro characterization

The aim of the present study was to develop and evaluate chronomodulated rupturable pulsatile drug delivery of theophylline for the treatment of nocturnal asthma. Core tablets containing theophylline were coated with two consecutive layers, an inner swelling layer and an outer rupturable coating layer. The effect of formulation variables such as molecular weight of outer rupturable coating layer, type and amount of swelling layer, weight gain of coating film and influence of paddle speed on drug release were investigated. The drug release from the pulsatile tablets exhibited an initial lag period, followed by a stage of rapid drug release. The optimal level of swelling layer (crospovidone) to achieve a fast and complete release was 20 % w/w. The results indicated that lag time was prolonged with the increased weight gain of coating film. Also no significant difference in the drug release was observed for different rotational speeds. In accordance with the chronomodulated therapy of asthma, the lag time criterion of 5 hours was satisfied by formulation having 11 % weight gain of outer rupturable layer.Colegio de Farmacéuticos de la Provincia de Buenos Aire

On the fraction of particles involved in magneto-centrifugally generated ultra-high energy electrons in the Crab pulsar

The earthward journey of ultra high energy electrons ($\sim 600$ TeV) produced in the Pulsar atmosphere by Landau damping of magneto-centrifugally excited Langmuir waves (drawing energy form the rotational slowdown) on primary electrons, is charted. It is shown, that just as they escape the light cylinder zone, the ultra-high energy particles, interacting with the medium of the Crab nebula, rapidly loose their energy via the quantum synchrotron process, producing highly energetic gamma rays ~ $\sim 0.6$PeV. Interacting with the cosmic background radiation in the interstellar medium, only a tiny fraction of these ultra high energy photons (via the $\gamma\gamma$ channel) are, then transformed into electron-positron pairs. Detected flux of these photons imposes an upper limit on the fraction ($4\times 10^{-7}$) of the magnetospheric particles involved in the process of generation of ultra-high energy photons (up to $600$ TeV).Comment: 8 pages, 2 figure