Dynamics of gap flow interference in a vibrating side-by-side arrangement of two circular cylinders at moderate Reynolds number

In this work, the coupled dynamics of the gap flow and the vortex-induced vibration (VIV) on a side-by-side (SBS) arrangement of two circular cylinders is numerically investigated at moderate Reynolds number 100 < Re < 800. Of particular interest is to establish a relationship between the VIV, the gap flow and the near-wake instability behind bluff bodies. We find that the kinematics of the VIV regulates the streamwise vorticity concentration, which accompanies with a recovery of two-dimensional hydrodynamic responses at the peak lock-in stage. On the other hand, the near-wake instability may develop around an in-determinant two-dimensional streamline saddle point along the interfaces of a pair of imbalanced counter-signed vorticity clusters. The vorticity concentration difference of adjacent vorticity clusters and the fluid momentum are closely interlinked with the prominence of streamwise vortical structures. In both SSBS and VSBS arrangements, the flip-flopping frequency is significantly low for the three-dimensional flow, except at the VIV lock-in stage for the VSBS arrangement. A quasi-stable deflected gap flow regime with negligible spanwise hydrodynamic (i.e., two-dimensional) response is found at the peak lock-in stage of VSBS arrangements. Owing to the gap-flow proximity interference, a high streamwise vorticity concentration is observed in its narrow near-wake region. The increase of the gap-flow proximity interference tends to stabilize the VIV lock-in, which eventually amplifies the spanwise correlation length and weakens the streamwise vortical structures. We employ the dynamic mode decomposition procedure to characterize the space-time evolution of the primary vortex wake

Volkov solutions for relativistic magnetized plasma in strong field quantum electrodynamics regime

This study shows the dynamics of relativistic electrons in terms of Dirac equation solutions when an ultra-intense short laser pulse of intensity $\ge 10^{23} {W.cm^{-2}}$ propagates through magnetized dense plasma ($B_0\approx {1MG})$. The interaction dynamics is analyzed near the strong-field quantum electrodynamics (SF-QED) regime. Our study finds new solutions in plasma media considering the effects of the re-normalized mass of relativistic electrons and the nonzero effective mass of accelerated photons. We have provided a general method for constructing exact solutions of the Dirac relativistic equation that correctly explains the dynamics of electrons in the strongly magnetized plasma medium. The modified solutions of the Dirac equation for one electron are derived and compared to the Volkov solutions. The new solutions are a basis for a feasible explanation of quantum attributes of relativistic electrons in a strong electromagnetic field of very short ultra-intense laser pulses with intensity near Schwinger field intensity. The solutions are called new Volkov solutions in a plasma medium. These solutions can be used to understand better the theory of quantum radiation reaction for the next-generation laser-plasma accelerator. Our results show that the Volkov solutions are not applicable in a magnetized plasma mediumComment: 14 pages,zero figure, journal articl

Integrated management of Ramularia blight (Ramularia foeniculi ) in fennel

Ramularia blight, caused by Ramularia foeniculi Sybille’s a highly destructive fennel disease and may cause complete failure of the crop. The use of chemicals especially mancozeb to manage Ramularia blight increases the load of residues in seed and reduces the export and market price. Removal of lower yellow leaves would not only help in reducing the load of Ramularia pathogen but, also increase the aeration in fennel crop. To manage this disease, field trial was conducted for three consecutive kharif seasons (2017-18, 2018-19 &amp; 2019-20) with agronomical practices i.e. removal of lower yellow leaves at different stages and different spraying schedules of chlorothalonil 75WP. Removal of lower yellow leaves at 50 % flowering stage and grain filling stage with two sprays of chlorothalonil 75WP @ 0.15% (20 g/ 10 lit. water) first spray at just appearance of disease and second spray at15 days after first spray was found effective not only in terms of management of disease (10.91 % disease incidence), yield (2078 kg/ha) and quality aspects but also reduced the load of fungicide on seed which promote the export. Thus, limited use (2 sprays) of chlorothalonil with the removal of lower yellow leaves helps to meet out the quality standards for export promotion with respect to residual limits in the said commodity

Management of phyllody in fennel by intercropping and insecticide use

Experiments were conducted during 2007–08 to 2010–11 at Centre for Research on Seed Spices, S.D. Agricultural University, Jagudan (Gujarat) for management of phyllody disease in fennel. Minimum incidence (9.80%) of phyllody with highest fennel equivalent yield (3035.28 kg ha-1) was observed in fennel inter cropped with green gram (1: 1). Maximum income Rs. 153632.60 ha-1 was observed in fennel + green gram intercropping. Minimum incidence of phyllody (9.19%) with highest yield (1947.17 kg ha-1) was recorded in seedling root dip in 0.04% Imidacloprid plus one spray of 0.005% Imidacloprid after one month of transplanting followed by seedling grown in 40 mesh nylon cloth net. &nbsp

Unusual acquired gastric outlet obstruction during infancy: a case report

Acquired gastric outlet obstruction (GOO) during infancy beyond the neonatal period is a very rare condition when other congenital causes like infantile hypertrophic pyloric stenosis, antral diaphragm, pyloric atresia etc are excluded. We report an unusual case of 6 month old male child who presented with recurrent episode of vomiting not relieved by medication. On gastrograffin study there was pre pyloric stricture of unknown etiology and was managed by stricturoplasty. We are reporting this case because of its rarity and with excellent outcome if diagnosed and managed properly. Even on extensive search of English literature we are not able to find a single report of this lesion in infants