Range Of Particle Densities Research Articles

Estimation of Soil Density, Porosity, Water Holding Capacity, and Moisture content of Arpa River Based Soil

Soil physics plays a pivotal role in the present scenario. It is directly related to the economic growth of India. An attempt has been made in this paper to research as well as estimate some important physical properties of the Arpa River-based soil of Bilaspur, Chhattisgarh. For soil analysis, it is required to calculate different Chemical, Physical, and Electrical properties, and Geographical. The physical properties of soil are influenced by the size, arrangement, composition, and properties of soil particles. Six distinct soil samples are taken for the current study from different places in the Arpa River. Many physical properties of these six soil samples are examined, including bulk density, particle density, porosity, water holding capacity, soil moisture content, and so on. which can be determined by different standard methods and mathematical formulas. The bulk density in this study ranges from 1.1332 to 1.466 g/cm3. The range of particle density is 2.0449 to 2.5252 g/cm3. After the determination of Bulk density and particle density, the percentage of solid space and pore space (Porosity) was evaluated. Water holding capacity varies from 8% to 48%. The moisture content of six samples varies from 25.92% to 48.14%. Based on physico-chemical parameters it is easy to find the type and amount of fertilizers for particular crops.

Bose Condensation of Upper-Branch Exciton-Polaritons in a Transferable Microcavity.

Exciton-polaritons are composite quasiparticles that result from the coupling of excitonic transitions and optical modes. They have been extensively studied because of their quantum phenomena and potential applications in unconventional coherent light sources and all-optical control elements. In this work, we report the observation of Bose-Einstein condensation of the upper polariton branch in a transferable WS2 monolayer microcavity. Near the condensation threshold, we observe a nonlinear increase in upper polariton intensity accompanied by a decrease in line width and an increase in temporal coherence, all of which are hallmarks of Bose-Einstein condensation. Simulations show that this condensation occurs within a specific particle density range, depending on the excitonic properties and pumping conditions. The manifestation of upper polariton condensation unlocks new possibilities for studying the condensate competition while linking it to practical realizations in polaritonic lasers. Our findings contribute to the understanding of bosonic systems and offer potential for the development of polaritonic devices.

Long-Wavelength Fluctuations in Quasi-2D Supercooled Liquids.

We use molecular simulation to characterize the dynamics of supercooled liquids confined in quasi-2D slit geometries. Similar to bulk supercooled liquids, the confined systems exhibit subdiffusive dynamics on intermediate time scales arising from particle localization inside their neighbor cages, followed by an eventual crossover to diffusive behavior as cage rearrangement occurs. The quasi-2D confined liquids also exhibit signatures of long-wavelength fluctuations (LWFs) in the lateral directions parallel to the confining walls, reminiscent of the collective displacements observed in 2D but not 3D systems. The magnitude of the LWFs increases with the lateral dimensions of systems with the same particle volume fraction and confinement length scale, consistent with the logarithmic scaling predicted for 2D Mermin-Wagner fluctuations. The amplitude of the fluctuations is a nonmonotonic function of the confinement length scale because of a competition between caging and strengthening LWFs upon approaching the 2D limit. Our findings suggest that LWFs may play an important role in understanding the behavior of confined supercooled liquids due to their prevalence over a surprisingly broad range of particle densities and confinement length scales.

Calculating Binodals and Interfacial Tension of Phase-Separated Condensates from Molecular Simulations with Finite-Size Corrections.

We illustrate three methods for calculating the binodals of phase-separated condensates from molecular simulations. Because molecular simulations can only be carried out for small system sizes, correction for finite sizes may be required for making direct comparison between calculated results and experimental data. We first summarize the three methods and then present detailed implementation of each method on a Lennard-Jones fluid. In the first method, chemical potentials are calculated over a range of particle densities in canonical-ensemble simulations; the densities of the dilute and dense phases at the given temperature are then found by a Maxwell equal-area construction. In Gibbs-ensemble Monte Carlo, the exchange between separated dilute and dense phases is simulated to obtain their densities. Lastly, slab-geometry molecular dynamics simulations model the dilute and dense phases in coexistence and yield not only their densities but also their interfacial tension. The three types of simulations are carried out for a range of system sizes, and the results are scaled to generate the binodals corrected for finite system sizes. Size-corrected interfacial tension is also produced from slab-geometry molecular dynamics simulations.

Assessment of Soil Physical Properties from Different Blocks of Jaipur District, Rajasthan, India

The year 2021-2022, An analysis experiment was done for identification physical properties from the Rajasthan state at the Jaipur district area. For further study, twenty-seven soil samples were taken from farmer's fields in different three blocks of Jaipur district at depths 0-15 cm, 15-30 cm and 30-45 cm. The soil texture in the examined region was sandy loam. The difference of soil color also noticed in both the Air-dry condition and Moist condition and the color was light yellowish brown (10YR6/4) to brownish yellow (10YR5/8) and bulk density was from 1.24-1.34 Mg m-3, The range of particle density was from 2.27-2.34 Mg m-3 and the pore space 37.77 to 43.65 %. The water retaining capacity % (WRC %) of soil ranged between 43.56 to 57.28 %. The specific gravity of soil ranged between 2.33 to 2.46. The manure and organic fertilizers are suitable for good soil health and maximum crop production at the farmer’s field.

Numerical investigation of laser-driven shock interaction with a deformable particle

A laser-driven shock propagating through an isolated particle embedded in a plastic (CH) target was studied using the radiation-hydrodynamic code FLASH. Preliminary simulations using IONMIX equations of state (EOS) showed significant differences in the shock Hugoniot of aluminum compared to experimental data in the low-pressure regime [O(10) GPa], resulting in higher streamwise compression and deformation of an aluminum particle. Hence, a simple modification to the ideal gas EOS was developed and employed to describe the target materials and examine the particle dynamics. The evolution of the pressure field demonstrated a complex wave interaction, resulting in a highly unsteady particle drag which featured two drag minima due to shock focusing at the rear end of the particle and rarefaction stretching due to laser shut-off. Although ∼30% lateral expansion and ∼25% streamwise compression were observed, the aluminum particle maintained considerable integrity without significant distortion. Additional simulations examined the particle response for a range of particle densities, sizes, and acoustic impedances. The results revealed that lighter particles such as aluminum gained significant momentum, reaching up to ∼96% of the shocked CH's speed, compared to ∼29% for the heavier tungsten particles. Despite the differences seen in the early stage of shock interaction, particles with varying acoustic impedances ultimately reached the same peak velocity. This identified particle-to-host density ratio is an important factor in determining the inviscid terminal velocity of the particle. In addition, the modified EOS model presented in this study could be used to approximate solid materials in hydrocodes that lack material strength models.

Fast recognition using convolutional neural network for the coal particle density range based on images captured under multiple light sources

A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study. The innovation is that two new images were constructed based on images captured under four single light sources. Reconstruction image 1 was constructed by fusing greyscale versions of the original images into one image, and Reconstruction image 2 was constructed based on the differences between the images captured under the different light sources. Subsequently, the four original images and two reconstructed images were input into the convolutional neural network AlexNet to recognize the density range in three cases: −1.5 (clean coal) and + 1.5 g/cm3 (non-clean coal); −1.8 (non-gangue) and + 1.8 g/cm3 (gangue); −1.5 (clean coal), 1.5–1.8 (middlings), and + 1.8 g/cm3 (gangue). The results show the following: (1) The reconstructed images, especially Reconstruction image 2, can effectively improve the recognition accuracy for the coal density range compared with images captured under single light source. (2) The recognition accuracies for gangue and non-gangue, clean coal and non-clean coal, and clean coal, middlings, and gangue reached 88.44%, 86.72% and 77.08%, respectively. (3) The recognition accuracy increases as the density moves further away from the boundary density.

Binding and neutralization of C. difficile toxins A and B by purified clinoptilolite-tuff.

Clostridioides difficile (C. difficile) infection is a major public health problem worldwide. The current treatment of C. difficile-associated diarrhea relies on the use of antibacterial agents. However, recurrences are frequent. The main virulence factors of C. difficile are two secreted cytotoxic proteins toxin A and toxin B. Alternative research exploring toxin binding by resins found a reduced rate of recurrence by administration of tolevamer. Hence, binding of exotoxins may be useful in preventing a relapse provided that the adsorbent is innocuous. Here, we examined the toxin binding capacity of G-PUR®, a purified version of natural clinoptilolite-tuff. Our observations showed that the purified clinoptilolite-tuff adsorbed clinically relevant amounts of C. difficile toxins A and B in vitro and neutralized their action in a Caco-2 intestinal model. This conclusion is based on four independent sets of findings: G-PUR® abrogated toxin-induced (i) RAC1 glucosylation, (ii) redistribution of occludin, (iii) rarefaction of the brush border as visualized by scanning electron microscopy and (iv) breakdown of the epithelial barrier recorded by transepithelial electrical resistance monitoring. Finally, we confirmed that the epithelial monolayer tolerated G-PUR® over a wide range of particle densities. Our findings justify the further exploration of purified clinoptilolite-tuff as a safe agent in the treatment and/or prevention of C. difficile-associated diarrhea.

Modeling Rydberg gases using random sequential adsorption on random graphs

The statistics of strongly interacting, ultracold Rydberg gases are governed by the interplay of two factors: geometrical restrictions induced by blockade effects, and quantum mechanical effects. To shed light on their relative roles in the statistics of Rydberg gases, we compare three models in this paper: a quantum mechanical model describing the excitation dynamics within a Rydberg gas, a Random Sequential Adsorption (RSA) process on a Random Geometric Graph (RGG), and a RSA process on a Decomposed Random Intersection Graph (DRIG). The latter model is new, and refers to choosing a particular subgraph of a mixture of two other random graphs. Contrary to the former two models, it lends itself for a rigorous mathematical analysis; and it is built specifically to have particular structural properties of a RGG. We establish for it a fluid limit describing the time-evolution of number of Rydberg atoms, and show numerically that the expression remains accurate across a wider range of particle densities than an earlier approach based on an RSA process on an Erdos-Renyi Random Graph (ERRG). Finally, we also come up with a new heuristic using random graphs that gives a recursion to describe a normalized pair-correlation function of a Rydberg gas. Our results suggest that even without dissipation, on long time scales the statistics are affected most by the geometrical restrictions induced by blockade effects, while on short time scales the statistics are affected most by quantum mechanical effects.

Evaluation of sugarcane bagasse ash for lightweight aggregates production

The present paper aims at researching the development of lightweight aggregates from sugarcane bagasse ash (SBA) sintering and binary mixtures of SBA and red clay (RC). Two different SBA were evaluated, which differ on their milling process: one was produced in a ball mill and the other in a knife mill. The average particle diameters of the resulting SBA were 2.99 µm and 20.47 µm, respectively. Each of these mills was evaluated in binary mixtures of SBA and RC, varying the SBA contents from 50% to 90%. Pure SBA and RC were also evaluated. Six different sintering temperatures were studied (1000 °C, 1050 °C, 1100 °C, 1150 °C, 1175 °C and 1200 °C). The precursor materials were characterized in terms of chemical, mineralogical composition, particle size distribution, specific surface area and thermal analysis, to be subsequently pelletized and sintered. After sintering, the bloating index, particle density, loose bulk density, water absorption, voids index, crushing strength and morphology analysis by scanning electron microscopy (SEM) were assessed. The results demonstrate that it is possible to obtain lightweight aggregates based on binary mixtures of SBA and RC in a wide range of particle densities, ranging from 1.03 to 1.67 g/cm3 and loose bulk densities ranging from 0.55 to 0.9 g/cm3. Bloating was observed only when smaller diameter SBA was used.

A commonly available and easily assembled device for extraction of bio/non-degradable microplastics from soil by flotation in NaBr solution

Soil microplastic pollution has caused widespread research attention worldwide. It is necessary to efficiently separate microplastic particles from soil matrixes in order to conduct studies of microplastic. And so far, few studies have described the separation and extraction devices of biodegradable microplastic. Here we present a commonly available device for extraction of non-degradable and biodegradable microplastics from soil samples in a NaBr solution based on density flotation. The device has a combined circulation and recovery system for the salt solution, which increases its environmental-friendliness. The accuracy and precision of the device was verified through spike and recovery experiments using three types of biodegradable microplastics (PBS, PBAT, PLA) and four types of non-degradable microplastics (LDPE, PS, PP, PVC), all with different particle sizes, and all microplastics are grinded autonomously, closer to reality. In despite of differences in particle size and density, for both biodegradable and non-degradable microplastics the device exhibited good extraction precision, with recovery rates ranging from 92% to 99.6%, over a wide range of particle densities and sizes. The recovery rates slightly increased with increased polymer density and microplastic particle size.

Wind regime, sediment transport, and landscape dynamics at a Mars analogue site in the Andes Mountains of Northwestern Argentina

The Puna Plateau of northwestern Argentina is a promising region for analogue investigations of Martian aeolian processes owing to its high altitude, low atmospheric pressure, aridity, geology, and widespread granular and bedrock aeolian landforms. Despite a growing body of research about the region's enigmatic aeolian landforms, little is known about the contemporary aeolian environment, processes, and landscape dynamics. To address this gap, we used a combination of modelled weather data, satellite imagery, and field measurements to characterize the wind regime, aeolian sediment transport, and allied surface changes. The study focused on the Campo de Piedra Pómez (CPP) – a volcanic landscape with a variety of Mars analogue landforms: gravel-mantled megaripples, yardangs, ventifacts, periodic bedrock ridges, and aeolian rat-tails. Modelled weather data from the European Center for Medium-Range Forecasting's ERA-Interim reanalysis dataset confirm the contemporary dominance of northwesterly winds in this region, consistent with the primary orientation of yardangs. These data also indicate the presence of less frequent southeasterly winds, which may explain why re-entrant profiles are observed on the southeast flanks of a small portion of the yardang population, and why some aeolian rat-tails point to the northwest. Observations from multi-temporal satellite imagery indicate that deposition and displacement of small sediment patches overlying ignimbrite bedrock is relatively common across the region. Samples retrieved from sediment traps deployed over one year in the region suggest a broad range of particle densities are mobilized by wind, which implies a wide range of wind speed for fluid entrainment. Conventional aeolian transport models do not consider the effects of particle density variations on transport processes. However, in areas with multiple density sediment present, our results point towards a need for aeolian models to consider density when quantifying and qualifying sediment transport.

Gaussian process post-processing for particle tracking velocimetry.

Particle tracking velocimetry (PTV) gives quantitative estimates of fluid flow velocities from images. But particle tracking is a complicated problem, and it often produces results that need substantial post-processing. We propose a novel Gaussian process regression-based post-processing step for PTV: The method smooths ("denoises") and densely interpolates velocity estimates while rejecting track irregularities. The method works under a large range of particle densities and fluid velocities. In addition, the method calculates standard deviances (error bars) for the velocity estimates, opening the possibility of propagating the standard deviances through subsequent processing and analysis. The accuracy of the method is experimentally evaluated using Optical Coherence Tomography images of particles in laminar flow in a pipe phantom. Following this, the method is used to quantify cilia-driven fluid flow and vorticity patterns in a developing Xenopus embryo.

Surface-to-bed heat transfer for high-density particles in conical spouted and spout–fluid beds

Bed-to-surface heat transfer experiments from a vertically submerged cylindrical surface were conducted in laboratory-scale (Dc=25cm) conical spouted and spout–fluid beds at two different conical angles (31° and 66°) in the high particle density range (2500kg/m3≤ρp≤6000kg/m3). The effects of the bed design parameters (conical angle and inlet diameter of spouting gas entrance) and operating conditions (static bed height, particle size, density, and spouting and fluidization gas flow rates) on the heat transfer characteristics were investigated in detail. The heat transfer coefficients were shown to be dependent on the density and size of the particles. The minimum stable spouting velocities of the denser and larger particles were higher, which led to higher operational spouting velocities and thereby resulted in higher heat transfer coefficients. The positive effect of increasing the particle diameter on heat transfer was more pronounced in the spout and at the spout–annulus interface, whereas this effect was diminished in the annulus region. The heat transfer coefficient increased with increasing spouting gas velocity up to 1.0Ums–1.1Ums, beyond which no significant change was observed regardless of the particle type. The heat transfer coefficient in the annulus decreased with increasing conical angle because of reduced particle circulation. The spout–fluid operation increased the heat transfer coefficient by a maximum of 10% at the expense of a significant increase of the total gas flow rate. This result was attributed to the inability of the fluidizing gas to penetrate the annulus. An empirical correlation for the average heat transfer coefficient in the annulus was also proposed based on the data obtained in this work.

Parameterization of In‐Cloud Aerosol Scavenging Due To Atmospheric Ionization: 2. Effects of Varying Particle Density

AbstractSimulations and parameterization of collision rate coefficients for aerosol particles with 3 μm radius droplets have been extended to a range of particle densities up to 2,000 kg m−3 for midtropospheric (~5 km) conditions (540 hPa, −17°C). The increasing weight has no effect on collisions for particle radii less than 0.2 μm, but for greater radii the weight effect becomes significant and usually decreases the collision rate coefficient. When increasing size and density of particles make the fall speed of the particle relative to undisturbed air approach to that of the droplet, the effect of the particle falling away in the stagnation region ahead of the droplet becomes important, and the probability of frontside collisions can decrease to zero. Collisions on the rear side of the droplet can be enhanced as particle weight increases, and for this the weight effect tends to increase the rate coefficients. For charges on the droplet and for large particles with density ρ < 1,000 kg m−3 the predominant effect increases in rate coefficient due to the short‐range attractive image electric force. With density ρ above about 1,000 kg m−3, the stagnation region prevents particles moving close to the droplet and reduces the effect of these short‐range forces. Together with previous work, it is now possible to obtain collision rate coefficients for realistic combinations of droplet charge, particle charge, droplet radius, particle radius, particle density, and relative humidity in clouds. The parameterization allows rapid access to these values for use in cloud models.

Resuspension of ash after the 2014 phreatic eruption at Ontake volcano, Japan

We determined the resuspension process of an ash deposit after the phreatic eruption of September 27th, 2014 at Ontake volcano, Japan, by analyzing the time series data of particle concentrations obtained using an optical particle counter and the characteristics of an ash sample. The time series of particle concentration was obtained by an optical particle counter installed 11km from the volcano from September 21st to October 19th, 2014. The time series contains counts of dust particles (ash and soil), pollen, and water drops, and was corrected to calculate the concentration of dust particles based on a polarization factor reflecting the optical anisotropy of particles. The dust concentration was compared with the time series of wind velocity. The dust concentration was high and the correlation coefficient with wind velocity was positive from September 28th to October 2nd. Grain-size analysis of an ash sample confirmed that the ash deposit contains abundant very fine particles (<30μm). Simple theoretical calculations revealed that the daily peaks of the moderate wind (a few m/s at 10m above the ground surface) were comparable with the threshold wind velocity for resuspension of an unconsolidated deposit with a wide range of particle densities. These results demonstrate that moderate wind drove the resuspension of an ash deposit containing abundant fine particles produced by the phreatic eruption.

A supersolid phase of hardcore boson in square optical superlattice

We have applied Quantum Monte Carlo technique to study the supersolid phase of hardcore bosons with nearest-neighbor repulsive interactions (NNRI) on square superlattice forming by an external potential. In a same NNRI model investigated by Batrouni et al. [Phys. Rev. Lett. 84, 1599 (2000)], there is no supersolid phase but phase separation. In this study, we have found the supersolid phase in the wide range of particle density with an assistance of the sufficient large external potential. Interestingly, a supersolid phase exists, on both the vacancy and interstitial sides. We have not found supersolid phase simultaneously existing with the crystals at any particle density. In the limit of a weak external potential strength, the system keeps all the features of the square lattice model which is similar to the model without an external potential. Increasing the external potential strength will induce the crystal phases at different filling factors commensurate with the external potential, i.e. ρ = 1 / 3 and 2/3 away from half filling. A strong external potential can even blow out the checkerboard crystal at half filling. The other possible relevance of these results to experiments on other similar systems such as the ultracold atom traping in optical lattice are discussed.

Magnetic vs. non-magnetic colloids – A comparative adsorption study to quantify the effect of dye-induced aggregation on the binding affinity of an organic dye

HypothesisDue to attractive magnetic forces, magnetic particles (MPs) can exhibit colloidal instability upon molecular adsorption. Thus, by comparing the dye adsorption isotherms of MPs and non-magnetic particles of the same size, shape and functional group it should be possible to characterize the influence of magnetic attraction on MP aggregation. ExperimentsFor a range of particle densities, a comparative adsorption study of malachite green (MG+) onto magnetic and non-magnetic colloids was carried out using a combination of a separation technique coupled with UV–vis spectroscopy, optical microscopy, and polarization dependent second harmonic generation (SHG) spectroscopy. FindingsSignificant MP aggregation occurs in aqueous solution due to MG+ adsorption. This alters the adsorption isotherm and challenges the determination of the adsorption equilibrium constant, Kads. The dye-induced aggregation is directly related to the MG+ concentration, [MG+]. A modified Langmuir equation, which incorporates loss of surface sites due to this aggregation, accurately describes the resulting adsorption isotherms. The Kads of 1.1 (±0.3)×107 and a loss of maximum MP surface capacity of 2.8 (±0.7)×103M−1 per [MG+] has been obtained. Additionally, SHG has been established as an effective tool to detect aggregation in nanoparticles.

Computational investigation of the effect of particle density on the multiphase flows and performance of hydrocyclone

Hydrocyclones are widely used to separate coal fines by size in the coal industry. They, however often face the problem associated with the misplacement of particles at the outlets due to the presence of a wide particle density range. This paper presents a numerical study of the multiphase flows and performance of hydrocyclone by means of two-fluid model, with special reference to particle density effect. The application of the model is firstly examined by comparing the measured and calculated results in terms of water velocities and particle partition curves. It is then used to investigate the behaviors of coal particles with different sizes and densities under different operational and geometrical conditions. The numerical results show that the separation efficiency of particles decreases with the decrease of particle density, and light coarse particles tend to be misplaced at the overflow outlet while ultrafine particles by-pass the separation in proportion to the water split. These results are in line with the experimental observations. This misplacement problem is attributed to the significant accumulation of particles and weakened swirling flow in the spigot area. Based on these findings, the modifications on the standard hydrocyclone by either lengthening conical section or using a convex cone are proposed to improve the performance of cyclones used to handle different sized particles with a wide density range. The results show that both modifications are useful to reduce the amount of light coarse particles misplaced at the overflow outlet.

Radial pressure profiles in a cold-flow gas-solid vortex reactor.

A unique normalized radial pressure profile characterizes the bed of a gas‐solid vortex reactor over a range of particle densities and sizes, solid capacities, and gas flow rates: 950–1240 kg/m3, 1–2 mm, 2 kg to maximum solids capacity, and 0.4–0.8 Nm3/s (corresponding to gas injection velocities of 55–110 m/s), respectively. The combined momentum conservation equations of both gas and solid phases predict this pressure profile when accounting for the corresponding measured particle velocities. The pressure profiles for a given type of particles and a given solids loading but for different gas injection velocities merge into a single curve when normalizing the pressures with the pressure value downstream of the bed. The normalized—with respect to the overall pressure drop—pressure profiles for different gas injection velocities in particle‐free flow merge in a unique profile. © 2015 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 61: 4114–4125, 2015