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Monolayer protected metal clusters comprise a rich class of molecular systems and are promising candidate materials for a variety of applications. While a growing number of protected nanoclusters have been synthesized and characterized in crystalline forms, their dynamical behavior in solution, including prenucleation cluster formation, is not well understood due to limitations both in characterization and first-principles modeling techniques. Recent advancements in machine-learned interatomic potentials are rapidly enabling the study of complex interactions such as dynamical behavior and reactivity on the nanoscale. Here, we develop an Au-S-C-H atomic cluster expansion (ACE) interatomic potential for efficient and accurate molecular dynamics simulations of thiolate-protected gold nanoclusters (Aun(SCH3)m). Trained on more than 30,000 density functional theory calculations of gold nanoclusters, the interatomic potential exhibits ab initio level accuracy in energies and forces and replicates nanocluster dynamics including thermal vibration and chiral inversion. Long dynamics simulations (up to 0.1 μs time scale) reveal a mechanism explaining the thermal instability of neutral Au25(SR)18 clusters. Specifically, we observe multiple stages of isomerization of the Au25(SR)18 cluster, including a chiral isomer. Additionally, we simulate coalescence of two Au25(SR)18 clusters and observe series of clusters where the formation mechanisms are critically mediated by ligand exchange in the form of [Au-S]n rings.

The collection mechanism inside the cloud is associated with the coalescence process. It controls the rainfall rate in the presence of high moisture content and low cloud condensation nuclei concentrations. The effectiveness of the coalescence mechanism is determined by the magnitude of the coalescence efficiency. This study compared the effectiveness of six coalescence efficiencies to identify the appropriate formulation, which can simulate the cloudburst event of 10 June 2021 over Sauni Binsar, Uttarakhand, at 11:45 IST (06:15 UTC). The coalescence efficiencies have been estimated between the lifting condensation levels and freezing levels over 100 equidistance intervals, with variation in the bins of colliding droplet pairs. The comparative analysis shows that Ochs’s formulation estimated high values of coalescence efficiencies ranging between 60 and 100% for all bins of droplet diameters during the cloudburst event. The maximum values of coalescence efficiency were found to be high for small cloud droplet diameter of 1–100 µm for collector droplet diameter of 50–7000 µm. The estimates provided by Seifert and Chen and Liu were below 80%, while Low and List, Beard and Ochs estimated coalescence efficiency values of up to 70% for all-collector cloud droplet diameters and small cloud droplet diameters. However, the estimated coalescence efficiencies by Brazier–Smith formulation are very low, not exceeding 20%, for all collector cloud droplet diameters and small cloud droplet diameters. The selection of appropriate coalescence parametrization is essential for appropriately simulating rainfall intensities using microphysics parametrization during extreme weather events. Research highlights: The coalescence process plays an important role in determining rain rate, and modelling it is a challenge. Six coalescence efficiencies have been estimated for the cloud burst event of Sauni Binsar, Uttarakhand, India. Ochs’s formulation estimated high values of coalescence efficiencies ranging between 60 and 100% for all bins of droplet diameter, which was expected. Seifert and Chen and Liu formulations estimated coalescence efficiencies below 80%, and Low and List and Beard and Ochs estimated coalescence efficiency up to 70% for the all-collector cloud droplet diameter and small cloud droplet diameter. The estimated coalescence efficiencies by Brazier–Smith formulation are very low, not exceeding 20%. [ABSTRACT FROM AUTHOR]

The coalescence of nanocrystals that occurs during low-temperature thermal treatments during the purification of hydroxyapatite from pigs has not yet been studied in the context of low-temperature environmentally friendly purification. To preserve the nature of hydroxyapatite, two extraction methods were investigated: Route 1 (autoclave and Soxhlet) and Route 2 (calcination at low temperatures with different times). The focus is on observing the effectiveness of removing fats and proteins while maintaining crystallite size and morphology. DSC showed that coalescence of crystallites occurred at 452, 566, 648, and 704 °C. Raw has a higher IR FWHM (phosphate band) due to the organic material; R1 had a lower FWHM (partial removal of lipids and proteins). Increasing the calcination temperature decreases the FWHM, indicating a shift in vibrational states from surface to bulk, leading to an increase in apparent crystallite size due to coalescence. For 20–80 h at quasi-stable temperatures of 400 and 500 °C, no significant changes occur in the IR spectrum. X-ray diffraction indicates the removal of organic material during calcination, as the peaks become clearer with increasing temperature. The crystallite size is not affected and remains in similar ranges. Purification with hydroxide shows an increase in both lattice parameters, in addition to the fluctuations that occur due to the ionic substitutions that naturally occur in biogenic HAp. And the TEM study confirms that the changes in apparent size from 2D to 3D are the result of the phenomenon of interplanar coalescence at low temperatures that occurs in sintering processes. [ABSTRACT FROM AUTHOR]

AbstractPickering Emulsions are commonly applied in the pharmaceutical, food, and chemical industries. The use of natural particles as stabilizers provides access to surfactant-free dispersions with reduced toxicity and environmental impact. This work investigates the use of three commercial organoclays (C15A, C10A, and C30B) and hydrophilic sodium montmorillonite (Mt) as stabilizers for Pickering emulsions. Emulsion stability was evaluated through macroscopic and microscopic morphological observations and the emulsion microstructure was characterized by optical microscopy and DLS measurements to assess creaming and coalescence. The influence of different experimental parameters on emulsion stability was evaluated, including organoclay content, emulsification time, emulsification speed, and oil–water ratio. The results showed that emulsions based on C15A exhibit better stability against coalescence as compared to emulsions prepared with the other clays. This was attributed to the wettability of the particles and solution viscosity. Droplet size decreased as emulsification time and stabilizer content increased and reached a minimum value at 1 wt.% of C15A and for emulsification time of 5 min and oil–water ratio O/W (v/v: 50/50). The experimental parameters also impacted emulsion viscosity, increasing it for high clay content and as the stirring speed and emulsification time increased. The results of the heat and cold resistance stability tests indicated that 25 °C represents the optimal storage temperature for the prepared emulsions. [ABSTRACT FROM AUTHOR]

The corrugated plate is the core component of a corrugated plate oil–water separator, which significantly influences oil–water separation efficiency. To study the influencing factors of oil droplets floating and coalescing on the lower surface of the corrugated plate, numerical simulation and experiments were used to analyze the effects of wave ratio, lower plate surface contact angle, oil viscosity, and oil droplet diameter on the floating of oil droplets on the coalescence of oil droplets. The results show that a moderate wave height ratio, lower contact angle, lower oil phase viscosity, and larger oil droplet diameter have better oil droplet agglomeration and floating effect. In the set parameter range, when the wave height ratio of the plate is 0.5, the contact angle of the lower surface of the plate is 30°, the oil phase viscosity is 0.0048 Pa s, and the oil droplet diameter is 8 mm, the oil droplet coalesces and floating effect are the best. [ABSTRACT FROM AUTHOR]

The use of Fused Filament Fabrication (FFF) of high-performance polymers is becoming increasingly prevalent, leading to the exploration of new applications. The use of such materials in critical cases for aerospace applications necessitates the verification of industry standards, particularly with regard to the requirements for part porosity. The authors investigate the effect of nozzle diameter and cooling temperature printing parameters on the porosity of the part by using existing modelling methods based on the sintering of cylinders and spheres and comparing the results to microscope snapshots of sections of parts. The models are able to be used as limits for predicting the longitudinal neck growth of the part. The authors show through experiments that the value of the cooling temperature of the deposited filament has a minimal effect on the outcome, while nozzle diameter has a strong impact on the resulting porosity. The modelling results show that there is a significant impact of both the nozzle diameter and cooling temperature on the porosity of the part. This implies that further refinement of the models is needed for the resulting parts to be applied in critical structures. [ABSTRACT FROM AUTHOR]

The study aims to eliminate the effect of coalescing filter blocking due to on–off operation by changing the wetting properties of the non-woven fiberglass filter media through their chemical modification with the use of a polydimethylsiloxane (PDMS) solution in hexane and a few commercial products that give the surface oleophobic properties. The best results—high separation efficiency, no redispersion of droplets at the outlet, and low flow resistance—were obtained for materials coated by immersion in a 0.2% PDMS solution, for which a reduction in oleophilicity was found, but the material was not oleophobic and still moderately wetted with the test liquid. The corresponding static contact angle with the VG-46 rotary compressor oil measured on the flat borosilicate glass wafer made of the same material as the fiberglass media was equal to 54° for the PDMS dip-coated surface. Moreover, the good stability of the applied polymer on the material surface was confirmed by the SEM imaging, the FTIR analysis, and maintaining a high performance in multiple tests run for a single coalescing element. [ABSTRACT FROM AUTHOR]

Cameron et al. (2010) and Fruehwald & Gorman (2011) present the pattern of homorganic consonant cluster reduction in Catalan as a challenge to Baković’s (2005) theory of antigemination, which predicts that any feature ignored in the determination of consonant identity for the purposes of antigemination in a given language must independently assimilate in that language. I argue that the pattern in Catalan is not a counterexample to this prediction if the reduction process is analyzed as coalescence, following Wheeler (2005), rather than as deletion.

The isotope distribution, which reflects the number and probabilities of occurrence of different isotopologues of a molecule, can be theoretically calculated. With the current generation of (ultra)‐high‐resolution mass spectrometers, the isotope distribution of molecules can be measured with high sensitivity, resolution, and mass accuracy. However, the observed isotope distribution can differ substantially from the expected isotope distribution. Although differences between the observed and expected isotope distribution can complicate the analysis and interpretation of mass spectral data, they can be helpful in a number of specific applications. These applications include, yet are not limited to, the identification of peptides in proteomics, elucidation of the elemental composition of small organic molecules and metabolites, as well as wading through peaks in mass spectra of complex bioorganic mixtures such as petroleum and humus. In this review, we give a nonexhaustive overview of factors that have an impact on the observed isotope distribution, such as elemental isotope deviations, ion sampling, ion interactions, electronic noise and dephasing, centroiding, and apodization. These factors occur at different stages of obtaining the isotope distribution: during the collection of the sample, during the ionization and intake of a molecule in a mass spectrometer, during the mass separation and detection of ionized molecules, and during signal processing. [ABSTRACT FROM AUTHOR]

If two ultrarelativistic nonrotating black holes of masses m 1 and m 2 approach each other with fixed center-of-momentum (COM) total energy E = s ≫ (m 1 + m 2) c 2 that has a corresponding Schwarzschild radius R = 2 G E / c 4 much larger than the Schwarzschild radii of the individual black holes, here it is conjectured that at the critical impact parameter b c between scattering and coalescing into a single black hole, there will be an inspiral of many orbital rotations for m 1 c 2 / E ≪ 1 and m 2 c 2 / E ≪ 1 before a final black hole forms, during which all of the initial kinetic energy will be radiated away in gravitational waves by the time the individual black holes coalesce and settle down to a stationary state. In the massless limit m 1 = m 2 = 0 , in which the black holes are replaced by classical massless point particles, it is conjectured that for the critical impact parameter, all of the total energy will be radiated away by the time the two particle worldlines merge and end. One might also conjecture that in the limit of starting with the massless particles having infinite energy in the infinite past with the correct ratio of impact parameter to energy, the spacetime for retarded time before the final worldline merger at zero energy will have a homothetic vector field and hence be self similar. Evidence against these conjectures is also discussed, and if it proves correct, I conjecture that two massless particles can form any number of black holes. [ABSTRACT FROM AUTHOR]

This study presents the interfacial behaviour of benzoylated cellulose of different wettability from melon and moringa pods waste using Pickering emulsions systems. The benzoylated cellulose was prepared in an aqueous alkaline medium using benzoyl chloride as a modifying agent and characterized by X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The X-ray diffraction showed that crystallinity of cellulose from moringa and melon are 67.47 and 70.20%, respectively. The functionalized derivatives are thermally stable than the native counterpart. The SEM revealed that isolated cellulose suffered surface degradation upon functionalization as a result of the repeated collision between reactants. The wetting properties of the cellulose can be controlled by using different quantities of modifying agents, and the emulsions stability depend on the wettability of the emulsifiers. The higher stability recorded for the emulsions stabilized by benzoylated cellulose from moringa pod waste revealed that cellulose wettability depends on the sources. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main purpose of this article is to model an industrial spiral-type gravitational coalescer by applying population balance as the governing equation. In this model, considering the two-dimensional movement of crude oil flow in the coalescer, the mechanisms of differential sedimentation, laminar shear, and Brownian motion are considered to determine the collision rate of droplets. Then, the population balance equation was solved to determine the droplet size distribution, dehydration, and desalination efficiency using the class method. The simulation results were in good match with the gathered industrial data. Finally, the influence of interfacial tension of water and oil, the pressure drop of the mixing valve, oil temperature, oil density, and washing water flow rate on the process efficiency was analyzed. The modeling results indicated that increasing the interfacial tension of water and oil from 30 to 36 mN/m and the oil density from 800 to 900 kg/m3 will decrease the water removal efficiency by 4.35% and 14.18%, respectively. Also, increasing the temperature of oil from 300 to 340 K and the volume fraction of washing water from 3% to 15% improves the efficiency of separating water from crude oil by 9.55% and 9.95%, respectively. [ABSTRACT FROM AUTHOR]

Piper (Piperaceae) is a species-rich pantropical genus (∼2000 species) with distinctive morphological characteristics such as swollen nodes, lack of a perianth, and one-seeded berry fruits. Sub-generic lineages within Piper are often associated with morphological traits and are well supported with molecular data, but sampling in previous studies was incomplete and conflict exists between morphological data and molecular inference. In this paper, Piper section Enckea is evaluated for monophyly by pairing DNA, primarily from herbarium material, with the Angiosperms353 bait set, high throughput sequencing, recently developed bioinformatic techniques, and two methods of phylogenetic reconstruction, maximum likelihood and multi-species coalescence. The results suggest continued support for recognition of Piper sect. Enckea as a monophyletic section and contribute to a better understanding of relationships among species within the section. However, they also raise questions about the morphological features used to define P. sect. Enckea and delimit species within the section. [ABSTRACT FROM AUTHOR]

Coalescence event in pendant and sessile droplets is distinguished by the formation and evolution of the liquid bridge created upon singular contact. For Newtonian droplets, the bridge radius, R , is known to evolve as R ∼ t b , with universal values of the power-law exponent, b , signifying the dominant governing forces. However, recent works on different subclasses of rheologically complex fluids comprising of macromolecules have highlighted the effects of additional forces on coalescence. In this work, we experimentally explore the phenomenon in distinct subclasses of rheologically complex fluids, namely, colloidal and noncolloidal suspensions, that have particle hydrodynamic interactions as the origin of viscoelasticity. Our observations suggest that such fluids have flow-dependent thinning responses with finite elasticity in shear rheology but negligible elasticity in extensional rheology. Based on these, the study extends the Newtonian universality of b = 0.5 to these thinning fluids. Further, we fortify these observations through a theoretical model developed by employing Ostwald–de Waele's constitutive law. Finally, we utilize this theoretical model to inspect the existence of arrested coalescence in generalized Newtonian fluids. [ABSTRACT FROM AUTHOR]

Oil and gas production activities elevate the risk of marine oil spills, exacerbated by oceanic dynamics that disperse and emulsify spilled oil. Coalescence emerges as a preferred oil/water separation method for its eco-friendly process. Coalescing media, crucial for effective oil removal, are composed of diverse materials. The healthcare sector generates substantial disposable fiber-based plastic waste, posing environmental threats upon disposal. This study presents a novel approach: creating a hierarchical porous structure on medical waste substrates using a cost-effective method. This structure, featuring macropores from pristine fibers maintaining high permeation rates and micropores from PVDF coating enhancing oil removal capabilities, offers an efficient coalescing medium. The design’s simplicity hints at industrial scalability. Testing the modified waste materials as coalescing media yielded an 85 % oil removal efficiency across varied oil types and water salinities. This study aligns with a circular economy paradigm, transforming waste into valuable resources.

This research examines different numerical techniques for modeling ferrofluids in a non-magnetic liquid subjected to homogeneous and steady magnetic field. It particularly compares the conservative level set method with the Volume of Fluid (VOF) and Simple Coupled Level Set and Volume of Fluid (SCLSVOF) methods. By comparing these methods with experimental data, we established the superiority of the utilized method in this study. Several case studies were conducted to evaluate how a homogeneous magnetic actuation affects ferrofluid dynamics, considering parameters such as initial droplet size, surface tension coefficient, and magnetic susceptibility. Additionally, the study explored the coalescence of two falling ferrofluid droplets under the combined effects of an external magnetic field and gravity. The conservative level set method was shown to be extendable to three-dimensional environments, unlike the standard level set method. The novelty of this work lies in demonstrating that the conservative level set method is particularly effective for ferrofluids, accurately capturing their complex dynamics. The main novelty of this article lies in demonstrating the precision of Conservative Level Set Method while utilizing a reduced number of equations compared to other works. This reduction in complexity enhances the method's efficiency without compromising precision, making it especially suited for applications requiring both speed and accuracy, such as model-based control systems.

Emulsification is one of the main mechanisms of chemical flooding to enhance oil recovery in heavy oil reservoirs. The emulsification of heavy oil in porous media is closely related to reservoir temperature and oil-displacing agent concentration. The relationship between the critical concentration and temperature of the oil-displacing agent required to form oil in water （O/W） emulsions in heavy oil was studied by emulsification experiment. The emulsification and migration rules of crude oil during chemical flooding of heavy oil were studied by using high-temperature and high-pressure microscopic visual oil displacement devices. The results show that a higher temperature in the emulsification experiment indicates that the crude oil is easier to emulsify， and the critical emulsification concentration of the required oil-displacing agent is lower. The critical emulsification concentration decreases by 90% when the temperature increases from 30 °C to 90 °C during the experiment. There are three modes of emulsification of heavy oil in porous media during microscopic oil displacement experiments for chemical flooding of heavy oil： the emulsification mode of heavy oil shows dispersion， migration， and coalescence at the throat in porous media when the concentration of the oil-displacing agent is less than the critical emulsification concentration of the oil-displacing agent required for heavy oil emulsification at this temperature； the emulsification mode of heavy oil indicates emulsification， migration， re-emulsification， and re-migration when the concentration of the oil-displacing agent is greater than the critical emulsification concentration of the oil-displacing agent required for heavy oil emulsification at this temperature； the emulsification mode of heavy oil is manifested as contact， stripping， and migration when the concentration of the oil-displacing agent is much larger than the critical emulsification concentration of the oil-displacing agent required for heavy oil emulsification at this temperature. Therefore， the concentration of the oil-displacing agent should be increased as much as possible to achieve efficient emulsification of heavy oil and improve oil recovery under the premise of controlling the cost when chemical flooding of heavy oil is carried out.

In this study,polytetrafluoroethylene(PTFE), a commonly used coalescence oil removal material, was selected and loaded with polyaniline(PANI) on its surface to successfully construct a superhydrophobic fiber material. It was then woven with hydrophilic cotton(Cot) fibers to form a superhydrophobic/hydrophilic heterogeneous material(PANI/PTFE-Cot) for the treatment of oily wastewater. The results indicated that PANI with micro-nano structure was successfully loaded on PTFE fibre, and the dosage of aniline and reaction temperature affected the hydrophobicity of PANI/PTFE. When the reaction temperature was 25 ℃ and the dosage of aniline was 0.2 mol/L,the water contact angle reached its maximum of 154°. Compared with that of PTFE,the quality factor of 2∶1 PANI/PTFE-Cot increased 46.7%.

The growing interest in the utilization of natural plant-derived products, particularly essential oils as eco-friendly agrochemicals has spurred the consumer demand for clean-label products. Due to their robust antimicrobial and pesticidal properties, essential oils (EOs) exhibit significant potential in food preservation and agricultural applications. However, the poor aqueous stability and highly volatile nature of EOs limit their potential for practical applications in their pure form. In response, nanoemulsions (NEms) have emerged as promising delivery vehicles for EOs, offering advantages such as smaller size, high solubilization capacity, excellent encapsulation efficiency, and controlled release characteristics.Here we review the recent advancements in the fabrication, optimization, and stability of EO NEms. The present article provides an in-depth exploration of all the currently available high-energy (ultrasonication, micro fluidization, high-pressure homogenization, rotor-stator mixer) and low-energy (spontaneous emulsification, phase inversion composition, emulsion inversion point, phase inversion temperature) methods being used for the fabrication of NEms and the respective advantages and disadvantages associated with them. Additionally, the review discusses various destabilization mechanisms such as Ostwald ripening, coalescence, etc. that generally impact essential oil NEms, providing a comprehensive understanding of the challenges associated with their stability. Furthermore, the review focuses on the recent practical applications of NEms in the sector of food preservation, flavoring agents, and sustainable agricultural practices.

Background and Aims Introgressive hybridization poses a challenge to taxonomic and phylogenetic understanding of taxa, particularly when there are high numbers of co-occurring, intercrossable species. The genus Quercus exemplifies this situation. Oaks are highly diverse in sympatry and cross freely, creating syngameons of interfertile species. Although a well-resolved, dated phylogeny is available for the American oak clade, evolutionary relationships within many of the more recently derived clades remain to be defined, particularly for the young and exceptionally diverse Mexican white oak clade. Here, we adopted an approach bridging micro- and macroevolutionary scales to resolve evolutionary relationships in a rapidly diversifying clade endemic to Mexico. Methods Ecological data and sequences of 155 low-copy nuclear genes were used to identify distinct lineages within the Quercus laeta complex. Concatenated and coalescent approaches were used to assess the phylogenetic placement of these lineages relative to the Mexican white oak clade. Phylogenetic network methods were applied to evaluate the timing and genomic significance of recent or historical introgression among lineages. Key Results The Q. laeta complex comprises six well-supported lineages, each restricted geographically and with mostly divergent climatic niches. Species trees corroborated that the different lineages are more closely related to other species of Mexican white oaks than to each other, suggesting that this complex is polyphyletic. Phylogenetic networks estimated events of ancient introgression that involved the ancestors of three present-day Q. laeta lineages. Conclusions The Q. laeta complex is a morphologically and ecologically related group of species rather than a clade. Currently, oak phylogenetics is at a turning point, at which it is necessary to integrate phylogenetics and ecology in broad regional samples to figure out species boundaries. Our study illuminates one of the more complicated of the Mexican white oak groups and lays groundwork for further taxonomic study. [ABSTRACT FROM AUTHOR]

The results of studies of hot cracks formed in cast shapes from low-alloy steel G21Mn5 are presented. Macroand microstructural analyses are carried out. Fractography studies of samples cut from castings used in the production of railway freight cars are performed. The criteria used to assess the susceptibility of alloys to hot brittleness are considered. It is shown that the orientation of dendritic crystals affects significantly the formation of hot cracks, and the direction of the dendrite growth is determined by the conditions of heat dissipation, which are influenced in their turn by the geometry of the casting. The phenomenon of coalescence under the conditions of misorientation of neighbor dendrites and its effect on the formation of hot cracks is studied. A modified RDG criterion is suggested, which allows for the influence of the geometry of the cast product on the formation of hot cracks through the angle of misorientation of neighbor crystals. [ABSTRACT FROM AUTHOR]

The dynamics of two gas bubbles rising in a stagnant viscous liquid is studied. The mathematical model is based on the laws of conservation of mass, momentum and energy, taking into account the compressibility of media. The gas is assumed to be calorically perfect. To trace the gas–liquid interface, the volume of fluid method is used. The solution to the problem is carried out using the finite volume method. The evolution of the bubble shape during the process of ascent and hydrodynamic interaction is shown. The change in the bubble shapes occurs under the influence of buoyancy force, drag force, viscous force, inertia force, and surface tension force. The results of the test calculations are in good agreement with the known data of other authors. The mechanism of coalescence of bubbles is described in the case of their movement one after another, when one bubble falls into the region of the hydrodynamic wake of another. Dependencies of bubble volume and temperature change on time are established. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The physical stability of a whey protein (WP)-stabilized red palm oil (RPO) emulsion as affected by the type and concentration of WP used was evaluated by monitoring the changes in its droplet characteristics after storage and accelerated testing. Emulsions containing 30% (v/v) RPO were stabilized by WP isolate 90 (WPI), WP concentrate 80 (WPC80), or WP concentrate 76 (WPC76) at various concentrations (2.5–15% (w/v)) via emulsification employing a two-step rotor-stator homogenization combined with a phase inversion technique. Based on the results, changes in droplet characteristics did not always represent the visually observed stability of the emulsions. In this study, WPCs performed better than WPI in forming a stable RPO emulsion. Higher WP concentrations produced smaller emulsion droplet sizes with better emulsion stability when stored at varied temperatures (i.e., 30 °C, 45 °C, and 60 °C). However, when stored at 60 °C, all the emulsions produced were least stable. Based on the results, the 15% WPC76-stabilized emulsion showed the best stability. This study found that the droplet size characterization could not fully explain the stability of the emulsion, and the emulsion investigated destabilized through different dominant mechanisms when it was stored compared to when it was centrifuged. This study provides information needed for developing a stable WP-stabilized emulsion to be the RPO carrier system. [ABSTRACT FROM AUTHOR]

Microinclusions in steel will significantly affect mechanical performance of final products and therefore require serious concern during metallurgical process. Herein, the collision, coalescence as well as floatation of bubble–inclusion coexisting system is fully studied through a new mathematical model. It comes to the following conclusions: as bubbles rise, they induce a flow of liquid steel from their upper surface to their lower surface, and inclusion droplets rise and collide in the wake of the bubble. The velocity of the bubbles is affected by their deformation, with deformation rates being linked to the Weber number. The coalescence time of these inclusions is primarily influenced by viscosity and surface tension. Coalescence accelerates with higher surface tension or reduced viscosity, and this phenomenon can be described by a formula, which is developed by simulation results. According to this formula, coalescence time of 3CaO·Al2O3 is 20% longer than that of 12CaO7·Al2O3. Consequently, 12CaO7·Al2O3 is more prone to coalescence. The movement of inclusions can be controlled by adjusting gas volume and flow rate. Moreover, promoting coalescence can be achieved by altering the viscosity of inclusions and the surface tension coefficient, making it easier to remove these unwanted inclusions. [ABSTRACT FROM AUTHOR]

Rapid species radiations present difficulties for phylogenetic reconstruction due to lack of phylogenetic information and processes such as deep coalescence/incomplete lineage sorting and hybridization. Phylogenomic data can overcome some of these difficulties. In this study, we use anchored hybrid enrichment (AHE) nuclear phylogenomic data and mitochondrial genomes recovered from AHE bycatch with several concatenated and coalescent approaches to reconstruct the poorly resolved radiation of the New Zealand cicada species in the genera Kikihia Dugdale and Maoricicada Dugdale. Compared with previous studies using only three to five Sanger‐sequenced genes, we find increased resolution across our phylogenies, but several branches remain unresolved due to topological conflict among genes. Some nodes that are strongly supported by traditional support measures like bootstraps and posterior probabilities still show significant gene and site concordance conflict. In addition, we find strong mito‐nuclear discordance; likely the result of interspecific hybridization events in the evolutionary history of Kikihia and Maoricicada. [ABSTRACT FROM AUTHOR]

The potential of a finite-element technique based on an egalitarian meshing of the space–time domain D of physical problems described by parabolic or hyperbolic differential equations is explored. A least-squares minimization technique is applied in the meshed domain D to obtain stiffness-like matrices associated with various linear differential operators. Applications discussed include problems of boundary growth, and diffusive coalescence, in which D cannot be regarded as the Cartesian product of two independent domains in space and time. [ABSTRACT FROM AUTHOR]

Ni–Al films produced by resistive thermal evaporation using a VUP-5 vacuum station are studied. The basic stages in film synthesis are described. The wavefront velocity in synthesis is determined, along with the radial growth rate of the nuclei (islands) formed. The grain size in the surface is investigated. Fourier analysis provides information regarding the structural properties of the surface. The electrical conductivity of the thin metallic film is determined. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is an escalating global health concern, exacerbated by the pervasive presence of antibiotic resistance genes (ARGs) in natural environments. The Yangtze River, the world's third-longest river, traversing areas with intense human activities, presents a unique ecosystem for studying the impact of these genes on human health. Here, we explored ARGs in the Yangtze River, examining 204 samples from six distinct habitats of approximately 6000 km of the river, including free-living and particle-associated settings, surface and bottom sediments, and surface and bottom bank soils. Employing shotgun sequencing, we generated an average of 13.69 Gb reads per sample. Our findings revealed a significantly higher abundance and diversity of ARGs in water-borne bacteria compared to other habitats. A notable pattern of resistome coalescence was observed within similar habitat types. In addition, we developed a framework for ranking the risk of ARG and a corresponding method for calculating the risk index. Applying them, we identified water-borne bacteria as the highest contributors to health risks, and noted an increase in ARG risks in particle-associated bacteria correlating with heightened anthropogenic activities. Further analysis using a weighted ARG risk index pinpointed the Chengdu–Chongqing and Yangtze River Delta urban agglomerations as regions of elevated health risk. These insights provide a critical new perspective on ARG health risk assessment, highlighting the urgent need for strategies to mitigate the impact of ARGs on human health and to preserve the ecological and economic sustainability of the Yangtze River for future human use.

We report the first measurements of cumulants, up to 4th order, of deuteron number distributions and proton-deuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair sNN=7.7 to 200 GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is observed across all collision energies and centralities, consistent with the expectation from global baryon number conservation. The UrQMD model coupled with a phase-space coalescence mechanism qualitatively reproduces the collision-energy dependence of cumulant ratios and proton-deuteron correlations.

Abstract Background Microbial communities are of tremendous importance for ecosystem functioning and yet we know little about the ecological processes driving the assembly of these communities in the environment. Here, we used an unprecedented experimental approach based on the manipulation of physical distance between neighboring cells during soil colonization to determine the role of bacterial interactions in soil community assembly. We hypothesized that experimentally manipulating the physical distance between bacterial cells will modify the interaction strengths leading to differences in microbial community composition, with increasing distance between neighbors favoring poor competitors. Results We found significant differences in both bacterial community diversity, composition and co-occurrence networks after soil colonization that were related to physical distancing. We show that reducing distances between cells resulted in a loss of bacterial diversity, with at least 41% of the dominant OTUs being significantly affected by physical distancing. Our results suggest that physical distancing may differentially modulate competitiveness between neighboring species depending on the taxa present in the community. The mixing of communities that assembled at high and low cell densities did not reveal any “home field advantage” during coalescence. This confirms that the observed differences in competitiveness were due to biotic rather than abiotic filtering. Conclusions Our study demonstrates that the competitiveness of bacteria strongly depends on cell density and community membership, therefore highlighting the fundamental role of microbial interactions in the assembly of soil communities.

The study aims to eliminate the effect of coalescing filter blocking due to on–off operation by changing the wetting properties of the non-woven fiberglass filter media through their chemical modification with the use of a polydimethylsiloxane (PDMS) solution in hexane and a few commercial products that give the surface oleophobic properties. The best results—high separation efficiency, no redispersion of droplets at the outlet, and low flow resistance—were obtained for materials coated by immersion in a 0.2% PDMS solution, for which a reduction in oleophilicity was found, but the material was not oleophobic and still moderately wetted with the test liquid. The corresponding static contact angle with the VG-46 rotary compressor oil measured on the flat borosilicate glass wafer made of the same material as the fiberglass media was equal to 54° for the PDMS dip-coated surface. Moreover, the good stability of the applied polymer on the material surface was confirmed by the SEM imaging, the FTIR analysis, and maintaining a high performance in multiple tests run for a single coalescing element.

Surfaces with micro/nano‐structures significantly enhance the critical heat flux of nucleate boiling by increasing the wickability of the liquid phase to delay film boiling. An alternative strategy, of removing surface bubbles at smaller sizes, is largely ignored. Here, they fabricate a rationally designed micro‐structured surface that enables the coalescence‐induced departure of microscopic vapor bubbles during the pool boiling of water at diameters an order of magnitude smaller than single‐bubble buoyant departure. Arrays of micro‐cavities or micro‐grooves serve as tailored nucleation sites to nucleate close‐packed vapor bubbles, which coalesce at unusually small sizes compared to a homogeneous surface. Two different modes of coalescence‐induced bubble departure are observed and modeled: capillary‐inertial jumping for smaller micro‐bubbles and buoyant‐inertial liftoff for larger micro‐bubbles. Capillarity‐enhanced pool boiling on micro‐structured surfaces has the potential to dramatically enhance the heat transfer coefficient and critical heat flux of pool boiling. [ABSTRACT FROM AUTHOR]

Chromosomal inversions may play a central role in speciation given their ability to locally reduce recombination and therefore genetic exchange between diverging populations. We analyzed long- and short-read whole-genome data from sympatric and allopatric populations of 2 Drosophila virilis group species, Drosophila montana and Drosophila flavomontana , to understand if inversions have contributed to their divergence. We identified 3 large alternatively fixed inversions on the X chromosome and one on each of the autosomes 4 and 5. A comparison of demographic models estimated for inverted and noninverted (colinear) chromosomal regions suggests that these inversions arose before the time of the species split. We detected a low rate of interspecific gene flow (introgression) from D. montana to D. flavomontana , which was further reduced inside inversions and was lower in allopatric than in sympatric populations. Together, these results suggest that the inversions were already present in the common ancestral population and that gene exchange between the sister taxa was reduced within inversions both before and after the onset of species divergence. Such ancestrally polymorphic inversions may foster speciation by allowing the accumulation of genetic divergence in loci involved in adaptation and reproductive isolation inside inversions early in the speciation process, while gene exchange at colinear regions continues until the evolving reproductive barriers complete speciation. The overlapping X inversions are particularly good candidates for driving the speciation process of D. montana and D. flavomontana , since they harbor strong genetic incompatibilities that were detected in a recent study of experimental introgression. [ABSTRACT FROM AUTHOR]

This work presents the factors that determine the coalescence of the micron-sized oil droplets (<0.4 μm) and the permeation flux by using two different types of commercial flat-sheet microporous polyvinylidene fluoride (PVDF) membranes. Results show that the PVDF-Westran membrane coalesced the oil droplets up to 1.1 μm while the PVDF-Synder membrane enlarged the oil droplets to approximately 5.6 μm. The pore size distribution instead of the both casted and fibrous membrane structures influenced the coalescence of the oil droplets. The membrane feed side that comprised of the smaller pores exhibited better in the coalescence while the pore size on the membrane permeate side did not show the significant effect on the coalescence. The water permeation flux was proportional to the pore size of the membrane feed side while the permeation flux during the coalescence was inversely proportional to the membrane pore size. The oil droplets in the feed solution has reduced the permeation flux about 10 times lower. The addition of the polyacrylamide in the oily water has essentially fouled the membranes at least 1.4 times higher and the foulant has induced the cleavage effect on the oil droplets. [ABSTRACT FROM AUTHOR]

Research efforts have been dedicated to predicting microstructural evolution during solidification processes. The main secondary arm spacing controls the mushy zone's permeability. The aim of the current work was to build a simple sub-grid model that describes the growth and coarsening of secondary side dendrite arms. The idea was to reduce the complexity of the curvature distribution with only two adjacent side arms in concurrence. The model was built and applied to the directional solidification of Al-06wt%Cu alloy in a Bridgman experiment. The model showed its effectiveness in predicting coarsening phenomena during the solidification of Al-06wt%Cu alloy. The results showed a rapid growth of both arms at an earlier stage of solidification, followed by the remelting of the smaller arm. In addition, the results are in good agreement with an available time-dependent expression which covers the growth and coarsening. Such model can be implemented as a sub-grid model in volume average models for the prediction of the evolution of the main secondary arms spacing during macroscopic solidification processes. [ABSTRACT FROM AUTHOR]

High shear mixing of powders in the presence of liquid addition can lead to the enlargement of primary powder particles, forming larger structures referred to as granules. This particle growth can occur through distinct mechanisms, including layering, coalescence, or a combination of both, and the prevailing mechanism is influenced by a multitude of process and formulation variables. In this study, we quantified the influence of process variables such as vessel inclination, rotational direction of the vessel, impeller speed, mixing duration, and rotation speed of the vessel pan on the particle growth mechanism. We accomplished this through rigorous image analysis of granule samples produced under varying conditions. Furthermore, our investigation extended to encompass the effects of formulation variables, including the particle density of the primary powder, the quantity of binder added, and the particle size of the coating material. Our findings revealed that the coating mechanism predominantly governed particle growth when the mixing time was brief, the mixer vessel had a high inclination angle, and the vessel rotated in a direction opposite to that of the agitator. The coating material utilization factor, denoting the ratio of the mass fraction of coating material added that effectively participates in the formation of coated seeds (each with a single seed) to the fraction of coating material engaged in competing mechanisms, serves as a crucial indicator of the prevailing mechanism within specific process and formulation conditions. [Display omitted] • Coating mechanism dominate when mixing time is short. • High inclination angle of vessel promotes coating. • At higher impeller speed longer mixing time diminishes coating efficiency and quality. • There is an inverse correlation between the number of coalesced seed particle and coating efficiency. [ABSTRACT FROM AUTHOR]

Abstract—The behavior of a "water-in-oil" emulsion stabilized with asphaltenes under the action of an inhomogeneous alternating electric field has been studied. The experimental technique was based on the use of microfluidics, optical microscopy, and high-speed video filming. The dependences of quantitative estimates of the parameters characterizing the dynamics of the emulsion destruction on the frequency and amplitude of the applied field have been obtained. The technique will be useful in developing efficient methods for breaking emulsions and modifying the existing technologies for separating oil emulsions into phases. [ABSTRACT FROM AUTHOR]

We study experimentally the flow of non-wetting ganglia during the co-injection of n-heptane and water in a predominantly 2D PMMA micromodel, which is constructed based on a stochastic digital algorithm. The dynamics of the phase distribution patterns are recorded optically and post-processed using cluster identification and motion tracking algorithms in order to study the characteristics and the interactions between the mobile and stranded ganglia populations. We focus primarily on the effects of the capillary number (Ca) and the ratio of the injection flow rates (Q) on the observed ganglia size distributions and the effective two-phase rheology. Our experimental setup allows for the study of ganglia fragmentation and coalescence dynamics over five orders of magnitude (in terms ganglia sizes), thus offering novel physical insight on the pore-scale characteristics of different ganglia populations and on how their interactions determine the relative permeability of the non-wetting phase. We demonstrate that the rates of ganglia fragmentation and coalescence intensify at higher Ca values, as viscous forces become dominant over capillary ones, leading to a log-normal size distribution that shifts toward smaller mean values. This effect is directly correlated with the emergence of new flow paths that develop progressively through narrower pores-throats, where the continuous wetting phase sweeps ganglia with sizes smaller than the mean pore-throat diameter. These flow paths further contribute to the Darcy scale velocity of the non-wetting phase, thus leading to a power-law Darcian regime at intermediate Ca values with a scaling exponent that is found to be a function of Q. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pickering emulsions are a kind of emulsion stabilized by solid particles. These particles generate a physical or mechanical barrier that provides long‐term stability to emulsion. Cellulose nanofibers are effective Pickering emulsifiers given their long length, high flexibility and entanglement capability. In this work, soybean hull insoluble polysaccharides (HIPS) were used as source of cellulose nanofibers by using a combination of chemical and mechanical treatment. The chemical composition, morphology, flow behavior, water holding capacity (WHC) and emulsifying properties of the nanofibers were studied. RESULTS: Nanofibers with diameters between 35 and 110 nm were obtained. The WHC increased significantly after the mechanical treatment, and the rheological behavior of the nanofibers was typical of cellulosic materials. Nanofibers were effective emulsifiers in oil‐in‐water (O/W) emulsions formulated under acidic conditions, without the need of using any additional surfactant. Emulsions were not affected by changes in the pH of the medium (3.00–5.00), and were stable to coalescence. CONCLUSION: It is possible that cellulose nanofibers form an entangled network which acts as a mechanical steric barrier, providing stability to coalescence. These results are important for the development of effective O/W Pickering emulsifiers/stabilizers, with large applications in the food industry. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations were conducted to investigate the coalescence mechanism of carbon nanoparticles. The analytical objects were two clusters composed of benzene, anthracene, phenanthrene or coronene molecules, and those clusters were placed next to each other. These numerical analyses used isoPAHAP potential to describe the intermolecular interaction and OPLS–AA potential to account for intramolecular interaction. Since the behavior below and above the melting point is entirely different, the melting point of the cluster was first determined. The coalescence behavior was investigated at temperatures 30 K below the melting point, 5 K below the melting point, and 50 K above the melting point. The coalescence of benzene clusters progressed through three stages: fast shrinking at 0–0.4 ns; gradual and constant shrinking at 0.4–4 ns; and little shrinking after 4 ns. This indicates that the coalescence of benzene clusters is analogous to that of inorganic nanoparticles. However, the number of coalescence stages of coronene clusters was more than four. The coronene cluster looked composed of 4–6 molecules of crystallites. Due to the strong interaction among molecules within crystallites, the diffusion of molecules in crystallites would hardly occur. Thus, the coalescence of coronene clusters would proceed with the breaking of crystallites. [Display omitted] • Carbon nanoparticles were assumed as PAH clusters. • Coalescence of carbon nanoparticle was investigated by MD simulation. • Coalescence was multi-staged, different mechanism from metal nanoparticles. [ABSTRACT FROM AUTHOR]

We investigate quasi-two-dimensional coalescence of domains of isotropic liquid in chiral liquid crystal in flat optical cells. It is demonstrated that coalescence can be accompanied by instability of the liquid crystal bridge separating the domains. We analyse the transformation of the bridge for materials in a wide range of the pitch of the cholesteric helix and different spatially modulated structures: planar cholesteric, one-dimensional stripe structure, focal conic structure and Blue Phases. The instability is followed by cascade break-up and formation of satellite cholesteric droplets. This picture differs from the standard three-dimensional coalescence scenario, where only a bridge between the droplets forms and grows. Studies of thinning dynamics in the bridge region showed that at the final stage of instability the width of the cholesteric bridge decreased linearly with time. In cholesteric with high chirality and small helical pitch the bridge thinning occurs substantially slower than in cholesteric with large helical pitch. [ABSTRACT FROM AUTHOR]