Dispersal Mechanisms Research Articles

Development of Lead‐Free Defect Brownmillerite Perovskite Ceramic LiBiFeMnO5 Solid Solution for Electronic Devices

This article reports the fabrication (synthesis) and characterizations (structural, microstructural topographic surface, dielectric, transport, impedance, current–voltage, and resistive properties) of a complex lead‐free defect perovskite material of composition LiBiFeMnO5. A preliminary structural investigation of the X‐ray diffraction pattern using N‐TREOR09 methods shows monoclinic symmetry. The scanning electron microscopic spectrum examines the sample's microstructural topographic surface, fractal study, and roughness (using the standard ISO25178). The analysis of Maxwell–Wagner dielectric dispersion, relaxation, and transport mechanisms is investigated utilizing dielectric, impedance, and conductivity spectrum accumulated within the experimental frequency of (1 kHz–1 MHz) at different temperatures (30–500 °C). A nonoverlapping small polaron tunneling conduction mechanism and correlated barrier hopping mechanism in the material have helped to understand its conduction phenomena. The Ohmic and space–charge limited conduction mechanisms are investigated by the slope of the logarithmic electric field (E) and current density (J). The thermistor constant (β) is determined to be 1982.87. The temperature coefficient of resistance is found to be −0.00419, which may be suitable for negative temperature coefficient thermistors, sensors, and other related devices.

Biofilm dispersal patterns revealed using far-red fluorogenic probes.

Bacteria frequently colonize niches by forming multicellular communities called biofilms. To explore new territories, cells exit biofilms through an active process called dispersal. Biofilm dispersal is essential for bacteria to spread between infection sites, yet how the process is executed at the single-cell level remains mysterious. Here, we characterize dispersal at unprecedented resolution for the global pathogen Vibrio cholerae. To do so, we first developed a far-red cell-labeling strategy that overcomes pitfalls of fluorescent protein-based approaches. We reveal that dispersal initiates at the biofilm periphery and ~25% of cells never disperse. We define novel micro-scale patterns that occur during dispersal, including biofilm compression and the formation of dynamic channels. These patterns are attenuated in mutants that reduce overall dispersal or that increase dispersal at the cost of homogenizing local mechanical properties. Collectively, our findings provide fundamental insights into the mechanisms of biofilm dispersal, advancing our understanding of how pathogens disseminate.

Chromosomal analysis of two Acanthodoras species (Doradidae, Siluriformes): Insights into the oldest thorny catfish clade and its karyotype evolution.

The Doradidae fishes constitute one of the most diverse groups of Neotropical freshwater environments. Acanthodoradinae is the oldest lineage and the sister group to all other thorny catfishes, and it includes only the genus Acanthodoras. The diversity of Acanthodoras remains underestimated, and the use of complementary approaches, including genetic studies, is an important step to better characterize this diversity and the relationships among the species within the genus. Therefore, we conducted a comprehensive analysis using conventional cytogenetic techniques and physical mapping of three multigene families (18S and 5S ribosomal DNA [rDNA], U2 small nuclear DNA [snDNA]) and four microsatellite motifs, namely (AC)n, (AT)n, (GA)n, and (GATA)n, in two sympatric species from the Negro River: Acanthodoras cataphractus and Acanthodoras cf. polygrammus. We found significant differences in constitutive heterochromatin (CH) content, distribution of the microsatellite (AT)n, and the number of 5S rDNA and U2 snDNA sites. These differences may result from chromosome rearrangements and repetitive DNA dispersal mechanisms. Furthermore, the characterization of the diploid number (2n) of these Acanthodoras species enables us to propose 2n = 58 chromosomes as the plesiomorphic 2n state in Doradidae based on ancestral state reconstruction. Acanthodoradinae is the oldest lineage of the thorny catfishes, and knowledge about its cytogenetic patterns is crucial for disentangling the karyotype evolution of the whole group. Thus, this study contributes to the understanding of the mechanisms behind chromosome diversification of Doradidae and highlights the importance of Acanthodoradinae in the evolutionary history of thorny catfishes.

Current expansion of the Barn Owl (<i>Tyto alba</i>) (Tytonidae, Aves) in Northern Eurasia

In the north of Eurasia, until the mid-twentieth century, the Barn Owl (Tyto alba) was sporadically distributed only in the Baltic states, in the west of Belarus and Ukraine, and in Moldova. Once, in 1942, a vagrant bird was caught in Turkmenistan also. At the end of the 20th century, reports appeared of rare recordings of barn owls in Eastern Europe, and since the beginning of the 21st century, pronounced expansion of these birds has been noted, observed in the south of Ukraine, Crimea, Ciscaucasia, and Transcaucasia. Different subspecies living in Central and Southern Europe and the Middle East are simultaneously expanding their nesting areas, namely: a. guttata, T. a. alba, and T. a. erlangeri. However, visual identification of subspecies and clarification of the direction of their expansion are complicated by the similarity of various forms and their significant individual variability associated with age, sex, intergradation with neighboring subspecies and other factors. The appearance of sedentary barn owls in new places is usually preceded by their post-nesting dispersion, directed in all directions and in some cases reaching 1–2 thousand km from the place of birth. Owing to the expansion of its range, barn owl populations have increased many times in a number of regions over the past decades, but accurate estimates of their numbers there are missing due to the rarity and sporadical nature of new finds, the very secretive lifestyle of these birds and insufficient knowledge of their ecology and ethology in the north of Eurasia. The article examines the taxonomy of various barn owl populations in Northern Eurasia and main diagnostic characteristics of some subspecies living in the north of Eurasia, as well as analyzes features of their historical and current distribution and expansion in Eurasia. The author also discusses possible causes and mechanisms of the barn owl dispersion and touches on information on the dynamics of their numbers in few regions.

Phenological gap in fruiting period and dispersal of seeds from alien fleshy-fruited plants by medium-sized carnivores in temperate forests of Central Europe

Some biological differences between native and alien plants are relevant to their dispersal mechanisms. One of them is the fruiting period: it is shifted in time, peaking later than in natives. Here we report the case study showing the temporal distance in fruiting phenology between native and alien plants and their seed dispersal via carnivorous mammals. From 2009 to 2011, scats of badgers Meles meles, foxes Vulpes vulpes, martens Martes spp. (M. martes and M. foina) and possibly also raccoon dogs Nyctereutes procyonoides (N = 820) were collected along transects totaling 30.4 km in length each month from June to November. We analyzed the frequency of occurrence of seeds (FO%) and the seed load in sampled scats; 61.7% of the sampled feces contained seeds of 18 fleshy-fruited native and alien plant taxa, and the most abundant seeds were from species with multi-seeded fruits such as Vaccinium myrtillus (94.6%), Rubus sp. (2.0%), and drupes of Prunus serotina (1.0%). The structure of dominance was characterized by seeds of Vaccinium myrtillus (15.0%), Pyrus sp. (14.8%) and Prunus serotina (13.0%) with aliens reaching high frequency of occurrence (FO%). The shares of seed FO% in the samples differed between alien and native plants. For seed load there were also significant interactions between the status of the seeds (alien or native) and the month of the vegetation period. Our data show the coincidence of two factors – the late fruiting period of alien plants and the decreasing availability of native fruits during the vegetation period. Such a set of factors may promote the dispersal of alien plant seeds by carnivorous mammals, which, unlike migrating birds, are constantly present in autumn. The limited availability of native fruits after their fruiting period, creating a phenological gap, makes alien plants the main source of fleshy-fruits at the end of vegetation period in forest ecosystems; this is expressed in high proportion of alien plants in seed FO%, and in significant interactions in the seed load in carnivore scats.

Rational Design of Liquid-Liquid Microdispersion Droplet Microreactors for the Controllable Synthesis of Highly Uniform and Monodispersed Dextran Microspheres.

Hydrogel microspheres are biocompatible materials widely used in biological and medical fields. Emulsification and stirring are the commonly used methods to prepare hydrogels. However, the size distribution is considerably wide, the monodispersity and the mechanical intensity are poor, and the stable operation conditions are comparatively narrow to meet some sophisticated applications. In this paper, a T-shaped stepwise microchannel combined with a simple side microchannel structure is developed to explore the liquid-liquid dispersion mechanism, interfacial evolution behavior, satellite droplet formation mechanism and separation, and the eventual successful synthesis of dextran hydrogel microspheres. The effect of the operation parameters on droplet and microsphere size is comprehensively studied. The flow pattern and the stable operation condition range are given, and mathematical prediction models are developed under three different flow regimes for droplet size prediction. Based on the stable operating conditions, a microdroplet-based method combined with UV light curing is developed to synthesize the dextran hydrogel microsphere. The highly uniform and monodispersed dextran microspheres with good mechanical intensity are synthesized in the developed microfluidic platform. The size of the microsphere could be tuned from 50 to 300 μm with a capillary number in the range of 0.006-0.742. This work not only provides a facile method for functional polymeric microsphere preparation but also offers important design guidelines for the development of a robust microreactor.

Biotic and abiotic dispersal of a large-seeded keystone genus in Madagascar

In tropical forests, most plant species rely on frugivorous animals for seed dispersal services. Such mutualisms are imperiled by defaunation, which disproportionately affects large-bodied vertebrates and may impact the interactions of the large-seeded plants they disperse. However, frugivore-mediated seed dispersal (zoochory) may not be the only mechanism ensuring the dispersal of a given plant species. With a focus on large-seeded canopy trees in the genus Canarium in the rainforests of Madagascar, thought to be dispersed by large-bodied lemur species, we investigated the contribution of multiple dispersal mechanisms to the movement of large seeds. Specifically, we (1) examined the potential for dispersal by abiotic factors, such as winds and runoff associated with frequent cyclones, (2) documented the animal species that could effectively contribute to their primary and secondary seed dispersal, and (3) determined how non-lemur and abiotic dispersal compare to the imperiled function of extant, though threatened, lemur primary dispersers. Using field observations and experiments, we found that wind, water, and secondary dispersal can move seeds considerable distances away from the parent plants, though they were less effective at long-distance dispersal than primary dispersers (i.e., large-bodied lemurs). For secondary dispersal, we found that dispersal distance is positively correlated with predation, potentially reducing dispersal effectiveness. Future comparisons with predation of primary or abiotically dispersed seeds will be necessary. Our research highlights the role of understudied mechanisms in the dispersal of large-seeded plants in Madagascar. Understanding the existence and impact of non-lemur dispersers in these imperiled forests can help complete our understanding of the mechanisms that shaped their astounding biodiversity and may mediate their response to ongoing environmental change.

Seed Availability and Small Mammal Populations: Insights from Mediterranean Forests

Plant–animal interactions play a crucial role in ecosystem functioning, especially through seed dispersal mechanisms. Understanding how small mammal populations respond to seed availability is essential for ecosystem management and biodiversity conservation, especially in the context of habitat loss and climate change. We conducted a 10-year study in mixed Mediterranean oak–beech forests to investigate the population dynamics of common small mammal species in response to seed availability. Our findings revealed distinct responses among species, influenced by life history traits, foraging behaviour, and diet. Wood mice (Apodemus sylvaticus) showed a rapid population increase with seed availability both in the same year of seed fall and the following year, suggesting a flexible foraging strategy and a dependence on arboreal seed producers. Yellow-necked mice (Apodemus flavicollis) revealed immediate population increases in response to seed availability in the autumn, probably because of their arboreal habits and preference for exploiting seeds prior to maturation. Bank voles (Clethrionomys glareolus) showed responses with population peaks in years following high seed availability, indicating a slower demographic response to resource abundance. Surprisingly, the greater white-toothed shrew (Crocidura russula) responded indirectly to seed availability in Mediterranean forests, suggesting complex interactions with seed-associated invertebrates or dependence on other variables not considered. Our findings highlight the importance of understanding how changes in seed availability influence the population ecology of small mammals, with significant implications for the conservation and management of Mediterranean forest ecosystems in the context of climate change and recurrent droughts. These results emphasise the need to consider species interactions, resource availability, and climate change in the conservation and management of evolving ecosystems.

Experimental evidence supports the ability of spotted lanternfly to hitchhike on vehicle exteriors as a mechanism for anthropogenic dispersal.

Historically, anecdotal observations support the likelihood of human-assisted invasive insect dispersal to new environments. No previous studies have investigated the ability of insects to remain attached to moving vehicles; however, such information is critical for prioritizing research, mitigation activities and understanding anthropogenic effects on biotic communities. Lycorma delicatula (White), spotted lanternfly (SLF), an invasive insect whose range is currently expanding throughout the United States, is commonly observed in urban settings and near transportation hubs. We developed a novel method to test SLF's ability to remain on vehicle surfaces including bonnet, nose wing, windscreen, wipers and scuttle panel using laminar wind flow from 0 to 100 ± 5 km h-1. We found all mobile life stages (nymphs and adults) could remain on the vehicle up to 100 km h-1. First instar nymphs and early season adults remained attached at significantly higher wind speeds than other stages. A brief acclimatization period prior to wind delivery increased attachment duration for all life stages except later season adults. The importance of outliers in the success of invasive species is well established. Given these results, any hitchhiking SLF could potentially establish incipient populations. This methodology will be beneficial for exploring human-assisted dispersal of other invasive arthropods.

Underpinning Plant Intelligence-A New Arena in Plant Cognition

Like other organisms plants also face crucial challenges for survival and better fitness in a wide range of ecological niches. Complex behaviors like learning, memory, information acquisition, communication, resolving problems and decision making abilities for their own benefits in an ever changing environment are also common in plants like humans and other animals. Plants sense and respond to biotic and abiotic factors of the environment to assess resources. Plants are good timekeepers as well. Without having proper brain and nervous system plants are able to interact with themselves and other organisms via chemical talking. In some plant species emissions of certain volatile chemicals during herbivore attacks are indications of social interactions. These are evidences regarding the occurrence of kin recognitions and responses in plant growth and development in complex environmental conditions. Certain species of plants show the act of mimicry. By adopting different dispersal mechanisms plant reduces parent-offspring and offspring-offspring competition. Seed-dispersal mutualism is a complex physiological interaction between plants and animals. For the last few years the relevance of plant cognition and behavioral ecology has received much attention. Collecting various sensory inputs from the surrounding environment (perception), transducing the signals within the body (cognition) and adapting various strategies plant ensures an output for better survival and reproductive fitness. All these mechanisms explore the domain of plant intelligence.

Theoretical and simulation analysis for R290 leakage from split-type air conditioners

Propane (R290) is a promising refrigerant for split-type household air conditioners with the advantages of energy saving, environmentally friendliness and low charge. Nevertheless, the large scale use of R290 has been hindered by its high flammability. The potential fire hazards can be relieved by reducing R290 releasable charge, and numerous methods have been put forward. In the authors’ previous papers, the method of refrigerant pump-down was proposed and a mathematical model of critical releasable charge (CRC, ignition threshold of leakage) was developed by dimensional analysis, but it is difficult to reflect the actual physical process of R290 dispersion. To reveal the leakage and dispersion mechanism of R290, a new numerical model of CRC is developed based on mechanism analysis in this work, in which the turbulent jet model, Coanda effect and dimensional analysis are involved. The predicted CRCs agree well with experimental and simulated data. Besides, the influence of indoor air speed with its direction parallel to the IDU panel on R290 concentration field is investigated by computational fluid dynamics (CFD) under different releasable charges. It is found that there is a transition value of air speed, below which the fire hazards decrease greatly with the increase of air speed, on the contrary, when the air speed is above the transition value, raising air speed has little impact on fire hazards.

Computational modeling of CH4 and CO2 adsorption on monolayer graphenylene: Implications for optoelectronic properties and hydrogen production

Graphenylene (GP) is a two–dimensional carbon allotrope with a hexagonal lattice structure containing periodic pores. The unique arrangement of GP offers potential applications in electronics, optoelectronics, energy storage, and gas separation. Specifically, its advantageous electronic and optical properties, make it a promising candidate for hydrogen production and advanced electronic devices. In this study, we employ a computational chemistry–based modeling approach to investigate the adsorption mechanisms of CH4 and CO2 on monolayer GP, with a specific focus on their effects on optical adsorption and electrical transport properties at room temperature. To simulate the adsorption dynamics as closely as possible to experimental conditions, we utilize the self–consistent charge tight–binding density functional theory (SCC–DFTB). Through semi–classical molecular dynamics (MD) simulations, we observe the formation of H2 molecules from the dissociation of CH4 and the formation of CO + O species from carbon dioxide molecules. This provides insights into the adsorption and dispersion mechanisms of CH4 and CO2 on GP. Furthermore, we explore the impact of molecular adsorption on optical absorption properties. Our results demonstrate that CH4 and CH2 affects drastically the optical adsorption of GP, while CO2 does not significantly affect the optical properties of the two–dimensional material. To analyze electron transport, we employ the open–boundary non–equilibrium Green's function method. By studying the conductivity of GP and graphene under voltage bias up to 300 mV, we gain valuable insights into the electrical transport properties of GP under optical absorption conditions. The findings from our computational modeling approach might contribute to a deeper understanding of the potential applications of GP in hydrogen production and advanced electronic devices.

Numerical and experimental approach for dust dispersion and deposition behavior for safe decommissioning activities

ABSTRACT The use of high-fidelity modeling is a promising technique for studying the mechanisms of dust dispersion and deposition in safe decommissioning operations. Detailed multiphysics models for poly-dispersed turbulent flow, particle-laden flow, and particle surface interaction were coupled with a Reynolds Averaged Navier Stokes method for numerical simulation of dust dispersion and deposition. A model that considered the critical viscosity was utilized to estimate the interaction between particles and substrate. The deposition behavior of particles was a result of the competition between adhesion and rebound probabilities during the impact process, and only when the critical viscosity exceeded that of the impacting particles could they attach to the surfaces. To validate the accuracy of the simulation results, deposition experiments using zirconia particles were conducted. The experimental setup included a 3.2 m polycarbonate pipe, a fan regulated by an inverter to control the flow, an ultra-low penetration air filter capable of capturing particles with a minimum diameter of 120 nanometers. An air pump connected to a particle tank and a mixing tank was used for homogenizing the injection of particles. Particle concentration was measured during the experiments using a light scattering spectrometer system, WELASⓇ 2000, from the manufacturer PalasⓇ. This optical measurement technique functioned with a white light source and scattered light detection. The scattered light was collected via optical fibers, which led to the control and evaluation point, and results were displayed through special software. The numerical simulation results were compared with the experimental data and used to validate the numerical approach for flow with zirconia particles deposited on various material surfaces, including iron, titanium, stainless steel 304, and stainless steel 316, for airflow rates ranging from 54 L/min to 124 L/min.

Physical chromosomal mapping of major ribosomal genes in 15 ant species with a review of hypotheses regarding evolution of the number and position of NORs in ants.

Recently, hypotheses regarding the evolutionary patterns of ribosomal genes in ant chromosomes have been under discussion. One of these hypotheses proposes a relationship between chromosomal location and the number of rDNA sites, suggesting that terminal locations facilitate the dispersion of rDNA clusters through ectopic recombination during meiosis, while intrachromosomal locations restrict them to a single chromosome pair. Another hypothesis suggests that the multiplication of rDNA sites could be associated with an increase in the chromosome number in Hymenoptera due to chromosomal fissions. In this study, we physically mapped rDNA sites in 15 new ant species and also reviewed data on rDNA available since the revision by Teixeira et al. (2021a). Our objectives were to investigate whether the new data confirm the relationship between chromosomal location and the number of rDNA sites, and whether the increase in the chromosome number is significant in the dispersion of rDNA clusters in ant karyotypes. Combining our new data with all information on ant cytogenetics published after 2021, 40 new species and nine new genera were assembled. Most species exhibited intrachromosomal rDNA sites on a single chromosome pair, while three species showed these genes in terminal regions of multiple chromosome pairs. On one hand, the hypothesis that the chromosomal location of rDNA clusters may facilitate the dispersion of rDNA sites in the ant genome, as previously discussed, was strengthened, but, on the other hand, the hypothesis of chromosomal fission as the main mechanism for dispersion of ribosomal genes in ants is likely to be refuted. Furthermore, in certain genera, the location of rDNA sites remained similar among the species studied, whereas in others, the distribution of these genes showed significant variation between species, suggesting a more dynamic chromosomal evolution.

Identification and Functional Implications of the E5 Oncogene Polymorphisms of Human Papillomavirus Type 16.

The persistence of the human papillomavirus type 16 (HPV16) infection on the cervical epithelium contributes to the progression of cervical cancer. Studies have demonstrated that HPV16 genetic variants may be associated with different risks of developing cervical cancer. However, the E5 oncoprotein of HPV16, which is related to several cellular mechanisms in the initial phases of the infection and thus contributes to carcinogenesis, is still little studied. Here we investigate the HPV16 E5 oncogene variants to assess the effects of different mutations on the biological function of the E5 protein. We detected and analyzed the HPV16 E5 oncogene polymorphisms and their phylogenetic relationships. After that, we proposed a tertiary structure analysis of the protein variants, preferential codon usage, and functional activity of the HPV16 E5 protein. Intra-type variants were grouped in the lineages A and D using in silico analysis. The mutations in E5 were located in the T-cell epitopes region. We therefore analyzed the interference of the HPV16 E5 protein in the NF-kB pathway. Our results showed that the variants HPV16E5_49PE and HPV16E5_85PE did not increase the potential of the pathway activation capacity. This study provides additional knowledge about the mechanisms of dispersion of the HPV16 E5 variants, providing evidence that these variants may be relevant to the modulation of the NF-κB signaling pathway.

Computer-driven formulation development of Ginsenoside Rh2 ternary solid dispersion.

(20S)-Ginsenoside Rh2 is a natural saponin derived from Panax ginseng Meyer (P. ginseng), which showed significantly potent anticancer properties. However, its low water solubility and bioavailability strongly restrict its pharmaceutical applications. The aim of current research is to develop a modified (20S)-Ginsenoside Rh2 formulation with high solubility, dissolution rate and bioavailability by combined computational and experimental methodology. The "PharmSD" model was employed to predict the optimal polymer for (20S)-Ginsenoside Rh2 solid dispersion formulations. The solubility of (20S)-Ginsenoside Rh2 in various polymers was assessed, and the optimal ternary solid dispersion was evaluated across different dissolution mediums. Characterization techniques included the Powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). Molecular dynamics simulations were employed to elucidate the formation mechanism of the solid dispersion and the interactions among active pharmaceutical ingredient (API) and excipient molecules. Cell and animal experiments were conducted to evaluate the in vivo performance of the modified formulation. The "PharmSD" solid dispersion model identified Gelucire 44/14 as the most effective polymer for enhancing the dissolution rate of Rh2. Subsequent experiment also confirmed that Gelucire 44/14 outperformed the other selected polymers. Moreover, the addition of the third component, sodium dodecyl sulfate (SDS), in the ternary solid dispersion formulation significantly amplified dissolution rates than the binary systems. Characterization experiments revealed that the API existed in an amorphous state and interacted via hydrogen bonding with SDS and Gelucire. Moreover, molecular modeling results provided additional evidence of hydrogen bonding interactions between the API and excipient molecules within the optimal ternary solid dispersion. Cell experiments demonstrated efflux ratio (EfR) of Rh2 ternary solid dispersion was lower than that of pure Rh2. In vivo experiments revealed that the modified formulation substantially improved the absorption of Rh2 in rats. Our research successfully developed an optimal ternary solid dispersion for Rh2 with high solubility, dissolution rate and bioavailability by integrated computational and experimental tools. The combination of Artificial Intelligence (AI) technology and molecular dynamics simulation is a wise way to support the future formulation development.

Dynamics of dispersal: Modeling the impact of dandelion proliferation on environmental and economic equilibria

Dandelion, with its unique wind dispersal mechanism, can easily spread its seeds across vast land areas, encroaching on territories of other creatures. To address this issue, two models are considered: The first model considers wind patterns, temperature, and moisture in dandelion growth, using differential equations to analyze population changes over time. Sensitivity analysis reveals the models responsiveness to these factors. The second model combines ecological and economic factors to assess the impact of invasive species, employing fuzzy mathematics to determine the severity of impact. The study identifies Canada Goldenrod as particularly destructive. These models offer insights for future invasive species management policies, showcasing innovations in incorporating partial differential functions and fuzzy mathematics for more accurate estimations.

Numerical simulation of agricultural unmanned helicopter corn canopy spraying

Plant protection by unmanned aerial vehicle (UAV) is a highly complicated process, especially considering the vast and diversified crop canopy. Furthermore, the droplet dispersal mechanism above and inside the crop canopy remains unclear. Owing to this, the authors used the lattice Boltzmann method (LBM) to simulate the application of plant protection UAV. The LBM is suitable not only to simulate the rotor tip vortex of UAV but also to model the crop canopy with detailed geometry. It is found that the streamwise and spanwise speed of the downwash flow achieve an extreme value both on top of the corn canopy and near the ground. When the droplet diameter decreased from 400 to 50 μm, its deposit region width doubled and its floating time increased from 3 s to more than 12 s. Small droplets are more likely to be lifted by the secondary flow near the ground and drift for a longer distance, while larger droplets are deposited directly. The increase in application height weakened the secondary spanwise flow near the ground and caused less droplet re-lifting and spanwise movement. The best point to initiate and terminate spraying is 2.5 m after passing the target corn canopy region. The droplet penetration rate in the canopy decreased with an increase in droplet size. This study used the LBM to model the unmanned helicopter application on a full corn canopy. Droplet deposition and distribution correspond to droplet size and canopy structure. The simulation results establish a foundation to optimize agricultural aerial spraying in an efficient and methodical manner.

Dispersion Behavior of a Droplet Impacting a Single Fiber.

The high-gravity reactor, known for its excellent mass transfer capability, plays a crucial role in the carbon capture process. The wire mesh packing serves as the core structure for enhancing mass transfer performance. Understanding the underlying dispersion mechanism requires a thorough exploration of the dynamics of droplet impact on a single fiber. This work aimed to numerically study the process of a droplet impacting a single fiber by applying the volume of fluid method. The effects of initial velocity (u0), initial diameter (D0), impact eccentric distance (e), and impact angle (θ) on the deformation evolution and dispersion characteristics of a droplet impacting a single fiber were systematically studied. Central or vertical impacts can be categorized into four main stages: splitting, merging, stretching, and breaking. Meanwhile, asynchronous breaking, sliding splitting, and oblique stages were observed during eccentric and nonvertical impacts. Subsequently, dimensionless time (t*) and the rate of increase of the gas-liquid interfacial area (η) were introduced to quantitatively analyze the dispersion characteristics postimpact. Increasing the initial velocity, reducing the droplet diameter, minimizing the impact eccentric distance, and maximizing the impact angle all contribute to enhanced dispersion performance. A correlation for the maximum increase rate of the gas-liquid interfacial area of the droplet was proposed, with errors less than ±15%. Finally, the deformation mechanism of droplet impact on a fiber was summarized by analyzing the influences of differential pressure inside and outside the liquid film, as well as gas vortices.

Floral Biology of Chinar (Platanus orientalis L.) under Temperate Conditions in the Kashmir Himalayas

Chinar, Platanus orientalis is a huge, widely distributed, and long-lived deciduous tree native to the eastern Mediterranean. It is the only species of the Platanaceae family found in India and grows throughout the valley. Since ancient times, this particular species has garnered fascination and reverence, leading to its continuous examination and admiration. However, the information related to its floral biology is meagre. The floral biology of P. orientalis is crucial to understanding its reproductive mechanisms and ecological interactions. The present study, therefore, aimed at investigating the floral characteristics of P. orientalis. For this study, seven young sexually mature trees were selected to study the floral characteristics. It was revealed that, in general, male flowers often emerge earlier than female blosssoms. The position of the male flower is always proximal and that of the female flower is distal when present on terminal branches. The average male female ratio recorded was 7:1 and the ratio between pollen and ovules on average was 9550 to 1. The pollen-ovule ratio is a fundamental reproductive parameter that provides insights into the reproductive strategies and ecological adaptations of plant species. The floral biology of P. orientalis demonstrates its adaptation to wind pollination and efficient seed dispersal mechanisms. This knowledge enhances comprehension and aids in gaining a deeper understanding of the reproductive strategies of P. orientalis and its ecological significance within its native range. Research in this field can help in developing effective conservation strategies and utilizing this species for research purposes.