A liquid film flowing down a fibre becomes unstable, leading to the formation of droplets that travel downstream. The droplet spacing and speed depend on the flow rate for a given nozzle and fibre radii. We show that fibre morphology further modifies the droplet spacing. In particular, we study the effect of the size of the beads in a granular chain on the evolution of the film thickness. We show that, when the size of the bead exceeds a critical value, the selection mechanism for instability modes is modified from regularly spaced droplets to coarsening by droplet merging. Droplet formation for flow over a single bead on the fibre is modified successively over subsequent beads in the downstream. Further, we show that if the perturbation in the flow produced by the bead is introduced as a velocity perturbation at the nozzle inlet, the formation of droplets on the fibre is qualitatively similar to that for the bead.

Recent experimental studies reveal that the near-wake region of a circular cylinder at hypersonic Mach numbers exhibits self-sustained flow oscillations. The oscillation frequency was found to have a universal behaviour. These oscillations are of a fundamentally different nature in comparison with flow oscillations caused due to vortex shedding, which are commonly observed in cylinder wakes at low-subsonic Mach numbers. The experimental observations suggest an aeroacoustic feedback loop to be the driving mechanism of the oscillations at high Mach numbers. An analytical aeroacoustic model that successfully predicts the experimentally observed frequencies and explains the universal behaviour is presented here. The model provides physical insights into and informs us of flow regimes where deviations from universal behaviour are to be expected. These findings hold relevance for a wider class of non-canonical wake flows at high Mach numbers.

Constrictive pericarditis is a rare complication after cardiac surgery. It is mostly seen in adults. We report a case of constrictive pericarditis in a 3-year-old child with right ventricular dysfunction after permanent pacemaker implantation during infancy for congenital complete heart block. Suspicion of constrictive pericarditis must be kept in mind during evaluation.

Experiments were conducted to assess the impact of crown architecture on light availability beneath the trees, flowering, fruiting, yield and quality of jamun (Syzygium cumini [L.] Skeels). Trees were maintained as control, palmette and open centre crown. Impact was evaluated for three consecutive years, i.e. 2017–2019. Diffuse light beneath the trees ranged from 69.7 ± 2.22 to 45.9 ± 1.45%, whereas direct light varied from 30.4 ± 0.97 to 54.1 ± 1.78%. At flowering and fruit development stage (June), photosynthesis rate (A) in control trees was 12.5 ± 0.43 μmol CO2/m2/s; however, at fruit maturity and dormancy (August), it was only 9.5 ± 0.35 μmol CO2/m2/s. Similarly, in palmette and open centre trees, photosynthesis rate at flowering and fruit development stage was 13.5 ± 0.46 and 15.7 ± 0.54 μmol CO2/m2/s, respectively; whereas at fruit maturity and dormancy, photosynthesis rate dropped to 10.5 ± 0.39 and 11.7 ± 0.43 μmol CO2/m2/s, respectively. Substantial variation in stomatal conductance (gs), vapour pressure deficit (VPD) and transpiration rate (E) was also found. Days to start flowering ranged from 92 ± 0.33 to 98 ± 0.33. Similarly, days to end flowering varied from 99 ± 0.07 to 107 ± 0.36, days to fruit set 132 ± 0.33 to 139 ± 0.33 and days to fruit maturity 176 ± 0.48 to 184 ± 0.63. Significant variation in fruit length, fruit width and fruit weight was also found. Total soluble solids in fruit pulp varied from 9.0 ± 0.15 to 12.2 ± 0.149°Brix and fruit yield 62.3 ± 1.5 to 86.7 ± 1.33 kg per tree. Noteworthy variation in fruit quality traits was also recorded. This study illustrates that crown architecture has considerable impact on gas exchange parameters, flowering, fruiting, yield and quality of jamun.

Coherent small-amplitude unsteadiness of the shock wave and the separation region over a canonical double cone flow, termed in literature as oscillation-type unsteadiness, is experimentally studied at Mach 6. The double cone model is defined by three non-dimensional geometric parameters: fore- and aft-cone angles ($\theta _1$ and $\theta _2$), and ratio of the conical slant lengths ($\varLambda$). Previous studies of oscillations have been qualitative in nature, and mostly restricted to a special case of the cone model with fixed $\theta _1 = 0^\circ$ and $\theta _2 = 90^\circ$ (referred to as the spike-cylinder model), where $\varLambda$ becomes the sole governing parameter. In the present effort we investigate the self-sustained flow oscillations in the $\theta _1$-$\varLambda$ parameter space for fixed $\theta _2 = 90^\circ$ using high-speed schlieren visualisation. The experiments reveal two distinct subtypes of oscillations, characterised by the motion (or lack thereof) of the separation point on the fore-cone surface. The global time scale associated with flow oscillation is extracted using spectral proper orthogonal decomposition. The non-dimensional frequency (Strouhal number) of oscillation is seen to exhibit distinct scaling for the two oscillation subtypes. The relationship observed between the local flow properties, instability of the shear layer, and geometric constraints on the flow suggests that an aeroacoustic feedback mechanism sustains the oscillations. Based on this understanding, a simple model with no empiricism is developed for the Strouhal number. The model predictions are found to match well with experimental measurements. The model provides helpful physical insight into the nature of the self-sustained flow oscillations over a double cone at high speeds.

The true characterization of elite germplasm is of utmost importance for accelerating the crop breeding programme. The Indian dolichos bean [Lablab purpureus (L.) var. typicus Prain] has the potential to improve nutritional and food security. In the present investigation, a total of 21 genotypes of dolichos bean, comprising local collections mainly, along with one standard check (Kashi Sheetal) were evaluated in a complete randomized block design with three replications for two consecutive years, 2021–22 to 2022–23 for the perusal of the genetic variability. Analysis of variance revealed significant differences among all the genotypes for all the characters. PCV and GCV estimates revealed very little influence of environment on the expression of traits under study. High heritability (>90%) estimates coupled with high genetic advance as a percent of the mean were observed for flower attributes, pod length, average weight of 10 pods, pod yield and protein content. The principal component analysis revealed that the first two components cumulatively accounted for more than 50% of total variability. The present investigation revealed that the genotypes, RLBDL-S-8, RLBDL-S-14 and RLBDL-S-4-5 were stable across the years and genotype RLBDL-S-8 exhibited the highest yield potential, which can be used effectively in the development of high yielding varieties of dolichos bean in the Bundelkhand region. The study also revealed the presence of wide genetic variability in the studied local accessions which is a prerequisite for the genetic improvement of crop plants. High heritability and genetic advancement indicated the scope of selection in the crop improvement.

The whitefly, Bemisia tabaci (Gennadius) is documented as a major pest on soybean. It was reported that whitefly response towards its hosts and their cultivars varies, and is mediated through various host-related factors. Considering the significance of leaf morphological characteristics in influencing the host–whitefly responses, the present investigation was conducted in screen-house conditions to study the prevailing variations in leaf morphological characteristics of soybean genotypes and their role in governing the adult whitefly attractiveness and oviposition preference. In the multiple-choice test, the whitefly population (eggs, nymphs and adults) was found to be lowest in moderately resistant genotypes (SL 1028 and SL 1074) compared to highly susceptible (DS 3105) and susceptible genotypes (SL 688, SL 958 and SL 1113). The foliar trichomes were characterized using scanning electron microscopy and leaf area, leaf lamina thickness and leaf shape data were acquired using standard procedures. To determine the factors involved in the resistance/susceptible responses towards whitefly, Pearson correlation was applied between the morphological characteristics and the whitefly population. The results show that the leaf area, trichome density, trichome length and trichome angle showed a significant positive correlation with the whitefly population, whereas leaf lamina thickness was negatively correlated. Thus, for developing whitefly-resistant germplasm, breeders should choose genotypes having narrow and thick leaves with sparse, short and flat trichomes.

The consequences of colonization have been linked to dehumanizing effects on a given people, but they can also be linked to a discourse that favors “depletion” of natural resources as their “utilization.” This article examines colonization as a subtle process of cultural devastation and ecological hegemony in the light of the memoir Unbowed by the late Nobel laureate from Africa, Wangari Maathai. 1Apart from framing the entire discussion with regard to the impact of colonization on environmental degradation, it also provides a glimpse into Maathai's life and works. We have attempted to analyze her thoughts and the efforts shared in her autobiography regarding the conservation of nature and natural resources, from her experiences stretching from the colonial to the postcolonial era.

Eggnog, a dairy-based beverage, comprises both milk and egg proteins. We aimed at optimizing the eggnog formulation using Box–Behnken design of response surface methodology. The combined effects of milk (60–75), cream (25–35) and eggnog base (6–8, all three as g 100/ml) were investigated on heat coagulation time, viscosity and thermal gelation temperature. ANOVA indicated that experimental data were well explained by a quadratic model with high check values (R2 > 0.94) and non-significant lack of fit tests. Based on the responses, an optimized formulation of eggnog with 60.0 milk, 25.0 cream and 6.50 eggnog base (as g 100/ml), could be considered best for manufacturing eggnog with desired attributes. This optimized formulation was characterized for physico-chemical, microbial and sensory attributes and the results indicated significantly higher fat and protein content than control formulation, but lesser lactose and total sugar content. Significantly higher viscosity, heat stability and lower thermal gelation temperature were also observed for the optimized formulation. Coliform, yeast and mold, E. coli and Salmonella counts were not detected in any sample but a significantly lower total plate count was observed for the optimized formulation.

Sustainability of maize production systems is threatened by poor economic returns and resource intensiveness. Therefore, an experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during 2016–17 to 2017–18 to assess the effect of tillage and microbial inoculantsintegrated phosphorus (P) management on productivity, quality, economic outcome and energy dynamics of maize. Three tillage practices viz., CT–R (conventional tillage with no residue), ZT–R (zero tillage with no residue) and ZT + R (zero tillage with wheat crop residue at 2.5 Mg/ha) were assigned in main plots and five P management practices viz., P1 (control–NK as per recommendation, but no P), P2 (17.2 kg P/ha), P3 (17.2 kg P/ha + PSB), P4 (17.2 kg P/ha + compost inoculants) and P5 (34.4 kg P/ha) were allocated in subplots in three times replicated split-plot design. The maximum grain yield (5.96 Mg/ha), protein content (9.13%), protein yield (546 kg/ha) and gross energy returns (209 × 103 MJ/ha) were recorded under ZT + R while higher benefit: cost ratio (B: C ratio – the amount of economic gain per unit investment) (1.53) and energy efficiency (12.5) was noticed under ZT–R. Among the P management practices, the application of 34.4 kg P/ha recorded the highest grain yield (6.45 Mg/ha), protein content (9.34%), protein yield (603 kg/ha), B: C ratio (1.65) and energy efficiency (10.1). The results suggested that the application of P at the rate of 34.4 kg/ha under ZT + R is an economically robust approach for the quality maize production in semi-arid region.

The work presented in this research communication was carried out to prepare low calorie synbiotic milk beverage by optimizing water and sugar level and to investigate the effect on its storage ability of different packaging materials (polypropylene, high impact polystyrene, high-density polyethylene and glass). Addition of both water and sugar significantly (P < 0.05) affected the viscosity, probiotic count and sensory properties. Based on the findings, 40% water and 8% sugar level were optimized for the preparation of the beverage. Apparent viscosity and acidity increased whilst pH and probiotic counts declined during storage, irrespective of packaging materials. The prepared beverage remained most acceptable at refrigeration temperature up to a period of 15 and 12 d when packaged in glass and high impact polystyrene, respectively. Furthermore, it retained a minimum recommended level of probiotic (7 log cfu/ml) during storage for 15 d at 4 °C.

We report a familial cluster of 24 individuals infected with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The index case had a travel history and spent 24 days in the house before being tested and was asymptomatic. Physical overcrowding in the house provided a favourable environment for intra-cluster infection transmission. Restriction of movement of family members due to countrywide lockdown limited the spread in community. Among the infected, only four individuals developed symptoms. The complete genome sequences of SARS-CoV-2 was retrieved using next-generation sequencing from eight clinical samples which demonstrated a 99.99% similarity with reference to Wuhan strain and the phylogenetic analysis demonstrated a distinct cluster, lying in the B.6.6 pangolin lineage.

Pulmonary valve endocarditis after transcatheter pulmonary valve implantation has been an emerging concern due to the increasing prevalence of transcatheter placement of pulmonary valve in the treatment of residual right ventricular outflow tract stenosis or regurgitation. Pulmonary valve endocarditis is a dreadful complication of transcatheter pulmonary valve implantation that have been reported with Melody valve (Medtronic, Inc., Minneapolis, MN) and Edward Sapien valve (Edwards Life Sciences, Irvine, CA) till date. There are scanty available literatures for pulmonary valve endocarditis with Venus P valve (Venus Medtech, Hangzhou, China) implantation. Furthermore, cardiovascular comorbidity is common in COVID-19 infection with limited evidence of COVID-19 infection concomitant with infective endocarditis. This case happens to be the first reported case of infective endocarditis of pulmonary valve with concomitant COVID-19 infection and also delayed presentation of pulmonary valve endocarditis with Venus P valve implantation.

Congenital heart block is a rare and lethal condition in paediatric population associated with maternal connective tissue disorders and rarely with structural cardiac disease like atrioventricular canal defects with or without left isomerism and congenitally corrected transposition of great arteries. Pacing in neonate if indicated is generally accomplished by epicardial pacing systems. However, in cases of significant bradycardia and haemodynamic instability, temporary pacemaker implantation via transvenous approach remains as a suitable option. Despite the advances in percutaneous catheter interventions, use of transvenous pacing in newborn is extremely challenging due to inadvertent risk of vessel injury, thrombus formation and mortality, and most of the time technical inability to place the lead within the right ventricular cavity. We report a case of congenital complete atrioventricular block in a premature male with birth weight of 1.51 kg who was managed with temporary pacemaker implantation through umbilical vein.

We investigate two-dimensional shallow granular flows on a rotating and gravitating elliptical body. This is motivated by regolith flow on small planetary bodies – also called minor planets – which is influenced by the rotation of the body, as well as its irregular topography and complex gravity field. Governing equations are obtained in an elliptic coordinate system attached to the body by extending the framework employed for terrestrial avalanches to incorporate effects of rotation, varying gravity and a curvilinear surface. Additionally, we introduce criteria to monitor grain shedding and to track flow initiation and cessation. We delineate different types of regolith motion that are governed by the rotation rate and surface roughness of the body. We find that grains migrate towards the minor and major axis of the body at low and high rotation rates, respectively. Grains are shed when the basal pressure vanishes, and shedding is encouraged by Coriolis effects during prograde flow. We observe the coexistence of regions of static and mobile regolith and their reorganization owing to the merging or division of flows. We also probe the formation and destruction of dunes – bulges arising from local grain accumulation – and find several aspects of their motion to be different from terrestrial situations. We then perform discrete element simulations that display a good match with theoretical predictions. Finally, we consider the evolution of a bi-disperse regolith. We find that big and small grains occupy, respectively, the top and bottom of the dunes formed on the surface, which is reminiscent of observations on asteroids like Itokawa.

Dispersion of droplets in an emulsion is commonly seen in several chemical, pharmaceutical and petroleum industries. Electric field has been shown to affect the stability of these dispersions. We study the dynamics of a pair of leaky dielectric droplets in a leaky dielectric liquid in the presence of an externally applied electric field. A pair of droplets may coalesce or repel each other in the presence of an electric field. Interactions between a pair of drops have been shown to be governed by the ratio $\varepsilon _r/\sigma _r$, where $\varepsilon _r$ and $\sigma _r$ are the ratios of drop to ambient fluid electric permittivities and conductivities, respectively. When inertia is neglected, the droplets approach each other if $\varepsilon _r/\sigma _r > 1$, whereas droplets repel when $\varepsilon _r/\sigma _r < 1$. However, inclusion of inertia permits interesting transient behaviour, where the droplets may attract due to the electrostatic dipole–dipole attraction even for $\varepsilon _r/\sigma _r < 1$. The approach velocity then is governed by the electrostatic forces and varies as $1/h^4$, where $h$ is the separation distance between the droplets, in contrast to being hydrodynamically driven as predicted in the Stokes flow limit by Baygents et al. (J. Fluid Mech., vol. 368, 1998, pp. 359–375). For compound droplets, interactions between droplets are essentially governed by the electrical properties of the outer droplet and the ambient fluid. However, transient dynamics may also result in the breakup of a compound droplet and lead to formation of single droplets.