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Journal articles on the topic 'Particle polydispersity'
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1
Zong, Ruoyu, Bin Liu, Xiao Jia, Shijun Wang, Shikun Li, and Xiulan Huai. "Numerical study on the polydispersive effect of filler size distribution on the properties of thermal interface materials." Journal of Physics: Conference Series 2827, no. 1 (2024): 012014. http://dx.doi.org/10.1088/1742-6596/2827/1/012014.
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Abstract Advanced thermal interface materials (TIMs) are indispensable for work reliability and lifespan assurance of high-power density electronic systems by facilitating timely and effective heat dissipation. A random algorithm consisting of diluting, dropping, and stirring processes is first proposed to simulate microstructures of TIMs with continuous particle size distribution, with an accessible maximum volume fraction of 55 vol%. Then the size polydispersity impact on the thermal performance and the fluidity of TIMs is numerically investigated. Simulation results reveal that as the particle size polydispersity increases, the thermal conductivity of TIMs improves, along with the improved fluidity. Therefore, it is necessary to consider the polydispersive impact of filler size distribution in actual production and optimize the material preparation process based on the actual distribution of particles. This work provides a deeper understanding of the influence of particle polydispersity on the co-optimization of the desired attributes of TIMs.
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Beaucage, G., H. K. Kammler, and S. E. Pratsinis. "Particle size distributions from small-angle scattering using global scattering functions." Journal of Applied Crystallography 37, no. 4 (2004): 523–35. http://dx.doi.org/10.1107/s0021889804008969.
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Control and quantification of particle size distribution is of importance in the application of nanoscale particles. For this reason, polydispersity in particle size has been the focus of many simulations of particle growth, especially for nanoparticles synthesized from aerosols such as fumed silica, titania and alumina. Single-source aerosols typically result in close to a log-normal distribution in size and micrograph evidence generally supports close to spherical particles, making such particles ideal candidates for considerations of polydispersity. Small-angle X-ray scattering (SAXS) is often used to measure particle size in terms of the radius of gyration,Rg, using Guinier's law, as well as particle surface area,S/V, from the Porod constantBand the scattering invariantQ. In this paper, the unified function is used to obtain these parameters and various moments of the particle size distribution are calculated. The particle size obtained from BET analysis of gas adsorption data directly agrees with the moment calculated fromS/V. Scattering results are also compared with TEM particle-counting results. The potential of scattering to distinguish between polydisperse single particles and polydisperse particles in aggregates is presented. A generalized index of polydispersity for symmetric particles, PDI =BRg4/(1.62G), whereGis the Guinier prefactor, is introduced and compared with other approaches to describe particle size distributions in SAXS, specifically the maximum-entropy method.
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Tretiakov, Konstantin V., and Krzysztof Hyżorek. "Strong Impact of Particle Size Polydispersity on the Thermal Conductivity of Yukawa Crystals." Materials 17, no. 20 (2024): 4955. http://dx.doi.org/10.3390/ma17204955.
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Control of thermal transport in colloidal crystals plays an important role in modern technologies. A deeper understanding of the governing heat transport processes in various systems, such as polydisperse colloidal crystals, is required. This study shows how strongly the particle size polydispersity of a model colloidal crystal influences the thermal conductivity. The thermal conductivity of model colloidal crystals has been calculated using molecular dynamics simulations. The model crystals created by particles interacting through Yukawa (screened-Coulomb) interaction are assumed to have a face-centered cubic structure. The influence of the Debye screening length, contact potential, and particle size polydispersity on the thermal conductivity of Yukawa crystals was investigated. It was found that an increase in particle size polydispersity causes a strong—almost fivefold—decrease in the thermal conductivity of Yukawa crystals. In addition, the obtained results showed that the effect of the particle size polydispersity on reducing the thermal conductivity of Yukawa crystals is stronger than changes in values of the Debye screening length or the contact potential.
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Angelidakis, V., S. Nadimi, and S. Utili. "A Particle Shape Classification Strategy to Inform the Generation of Representative Element Volumes in the Discrete Element Method." IOP Conference Series: Earth and Environmental Science 1480, no. 1 (2025): 012077. https://doi.org/10.1088/1755-1315/1480/1/012077.
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Abstract Granular soils feature a wide variety of particle sizes and shapes which makes their discrete simulation a laborious task, as the question arises of what particle shapes should be used to model a real geomaterial. This study introduces a method to generate simplified Representative Element Volumes (REVs) of non-spherical particles in the Discrete Element Method (DEM) with reduced particle shape polydispersity, which nevertheless still represent adequately the shear strength of the real material. A recently-proposed shape classification system is employed to categorise real particles as flat, compact, bladed and elongated, which is based on new definitions of particle flatness and elongation, and representative particles of each shape type are identified. It is shown that REVs of railway ballast with simplified representation of shape polydispersity can adequately represent the shear strength of the real material under triaxial compression, as long as the statistical distribution of flat, compact, bladed and elongated particles is in proportion to that of the real material.
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Brown, David P., Albert G. Nasibulin, and Esko I. Kauppinen. "CFD-Aerosol Modeling of the Effects of Wall Composition and Inlet Conditions on Carbon Nanotube Catalyst Particle Activity." Journal of Nanoscience and Nanotechnology 8, no. 8 (2008): 3803–19. http://dx.doi.org/10.1166/jnn.2008.453.
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The evolution of iron catalyst particles during aerosol (floating catalyst) Chemical Vapor Deposition (CVD) synthesis of Carbon Nanotubes (CNTs) from CO is computed using a multi species Computational Fluid Dynamics (CFD) model incorporating a lognormal aerosol method of moments (MOM) to describe their dynamics and a combined chemical kinetics and equilibrium model for catalytic production of CO2. The influence of the presence of iron at the reactor walls, the fed particle size, number concentration and polydispersity and the effect of the catalytic production of CO2 at the reactor wall are studied in terms of particle size, concentration and polydispersity and reagent concentration during CNT synthesis. It is found that iron catalyst particle dynamics are essentially insensitive to wall iron concentrations and, for a wide range of particle sizes and concentrations, it is found that the catalyst particles are stable up to a critical CNT window in which CNT nucleation and growth occurs. Concentrations of catalyst particles significantly above 1 × 1014 #/m3, however, lead to poor control over catalyst particle size and polydispersity at the CNT nucleation front which, in turn, leads to poor control over CNT diameter. The location of the growth window is shown to be directly associated with the availability of catalytically produced CO2 diffusing from the reactor walls to the reactor core. These results help to explain the large variations in CNT diameter and chirality and the inefficient use of catalyst material in other floating catalyst CNT processes based on in-situ catalyst particle synthesis.
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B. Ma’arif, Y. Tamara, F. A. S. Al-Azzam, et al. "THE FORMULATION OF SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM OF ETHANOL EXTRACT OF Marsilea crenata C. Presl. LEAVES." RASAYAN Journal of Chemistry 16, no. 02 (2023): 934–43. http://dx.doi.org/10.31788/rjc.2023.1628342.
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Marsilea crenata C. Presl. contains phytoestrogens, which have structures or activity similar to estrogen and could potentially be utilized as a neuroprotector in an estrogen deficiency disease. This study aims to utilize M. crenata in the formulation of SNEDDS as a neuroprotector. The dosage form chosen aims to maintain stability and effectiveness because of its multi-compound properties. M. crenata was extracted using ethanol, then formulated into four SNEDDS formulas, and then characterization was done, which included physical quality (organoleptic and pH), particle size, polydispersity index, transmittance percentage, and Scanning Electron Microscope (SEM) analysis. The results showed that the four formulas produced a homogenous yellow color with a distinctive odor formulation; the values of the pH, particle size, polydispersity index, and transmittance percentage were still in the allowable range; and the SEM analysis showed that SNEDDS particles dominated with a spherical shape of particles. It can be concluded that the ethanol extract of M. crenata leaves can be formulated into SNEDDS and the best SNEDDS formulation was formula B at 100 ppm extract concentration which had the smallest particle size, smallest polydispersity index, and the largest transmission percentage.
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Mallikarachchi, Sadeepa Y., Nancy C. Rotich, Emma Gordon, and Ann E. Hagerman. "Different Chain Length Tannic Acid Preparations as Coating Agents for Zein Nanoparticles." Compounds 4, no. 2 (2024): 401–14. http://dx.doi.org/10.3390/compounds4020024.
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Proteins that are amphiphilic and have low water solubility can self-assemble into nanoparticles useful in food science, pharmaceutical science, or biotechnology. However, protein nanoparticles exhibit drawbacks such as low stability unless the particles are coated. In the current study, tannic acid is the coating agent for nanoparticles synthesized from the protein zein. Tannic acid is a hydrolyzable tannin comprising a polyol esterified with galloyl residues. The nominal molecular formula of tannic acid (C76H52O46) suggests the material is decagalloyl glucose, obscuring its complex composition as a mixture of galloyl esters of glucose. We prepared hollow zein nanoparticles and coated them with tannic acid preparations that had short or long galloyl ester chains. The % α-helix of zein in nanoparticles is lower than in native zein but there is no effect of coating the particles with tannic acid. Interactions between the tannic acid and the zein slightly perturb the IR spectrum of the protein but there is no effect of galloyl chain length. We confirmed that tannic acid-coated particles have a more negative zeta potential, suggesting greater stability compared to uncoated particles. Coating with longer chain length tannic acid reduces particle diameter and tends to decrease polydispersity but does not change particle digestibility. Coating with shorter galloyl chain length tannic acid tends not to change particle diameter, reduces polydispersity of the particles, and stabilizes particles to enzymatic digestion. Tannic acid is a naturally occurring tunable coating for nanoparticles that can be used to adjust properties such as particle size, polydispersity, and digestibility for specific purposes.
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Averkin, D. V. "Effect of surfactants on the degree of polydispersity of a suspension of polystyrene latex spheres." Izmeritel`naya Tekhnika, no. 3 (May 15, 2024): 55–60. http://dx.doi.org/10.32446/0368-1025it.2024-3-55-60.
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The problem of satisfying the needs of the domestic market of the Russian Federation for creating domestic particle size standard reference materials in liquids to ensure uniformity in measurements of the granulometric composition of aerosols and powdery substances is considered. It is known that, under various conditions, monodisperse suspensions of polystyrene latex spheres can be synthesized, both monodisperse and polydisperse samples being obtainable. The effect of the composition and solubility of surfactants in a styrene-based water emulsion on the particle size of suspensions obtained as a result of emulsion polymerization, and their polydispersity, has been investigated. The metrological characteristics of polystyrene suspensions based on sodium, potassium, and lithium laureths synthesized in this study were determined using dynamic light scattering and laser diffraction techniques. It has been found that the size and degree of polydispersity of particles in suspensions based on lauric acid salts is primarily influenced by the solubility of the surfactant and the surface tension of the interfacial layer formed between styrene and water at the time of particle formation. The effect of the rate of reaction, as well as the concentration of surfactants, on the size and polydispersity of the synthesized particles, has been studied. It has been found that when potassium persulfate is used as the initiator in the reaction, particle size distributions are monodisperse for suspensions based on sodium or potassium laureate. The polydispersity degree of lithium laureate-based suspensions is approximately 1.5 to 2 times higher compared to other suspension samples. When azoisobutyronitrile is used as an initiator, all suspensions samples are monodisperse. It has been experimentally determined that the achievement of monodisperse samples is due to the polymer-monomer particle formation time, which is comparable to the monomer transformation rate. The results obtained will be utilized in the development and establishment of particle size standard reference materials for storage and reproduction of particle size values within a liquid medium.
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Fernández-Rico, Carla, and Roel P. A. Dullens. "Hierarchical self-assembly of polydisperse colloidal bananas into a two-dimensional vortex phase." Proceedings of the National Academy of Sciences 118, no. 33 (2021): e2107241118. http://dx.doi.org/10.1073/pnas.2107241118.
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Self-assembly of microscopic building blocks into highly ordered and functional structures is ubiquitous in nature and found at all length scales. Hierarchical structures formed by colloidal building blocks are typically assembled from monodisperse particles interacting via engineered directional interactions. Here, we show that polydisperse colloidal bananas self-assemble into a complex and hierarchical quasi–two-dimensional structure, called the vortex phase, only due to excluded volume interactions and polydispersity in the particle curvature. Using confocal microscopy, we uncover the remarkable formation mechanism of the vortex phase and characterize its exotic structure and dynamics at the single-particle level. These results demonstrate that hierarchical self-assembly of complex materials can be solely driven by entropy and shape polydispersity of the constituting particles.
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Zubarev, A. Yu, and L. Yu Iskakova. "Effect of polydispersity on magnetoviscous properties of ferrofluids." Magnetohydrodynamics 58, no. 3 (2023): 275–84. http://dx.doi.org/10.22364/mhd.58.3.4.
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The paper deals with a theoretical study of the magnetoviscous effect in polydisperse ferrofluids. A two-fractional model of colloid consisting of relatively large and small particles is studied. The model is based on the idea that the magnetoviscous effect is determined by chain-like aggregates formed by large particles. The effect of the small particle fraction is determined by two factors: (i) the magnetic interaction between large and small particles, which leads to a reduction of the chain length and weakening of the fluid magnetoviscosity, (ii) the steric interaction between small and large particles, which enlarges the chain length, therefore, enhances this effect. The resulting effect is determined by the ratio of the sizes of large and small particles. Figs 2, Refs 17.
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Nurfatihayati, Nurfatihayati, Ahmad Fadli, Sunarno Sunarno, Allailus Syah Safara, and Aulia Permatasari. "Modifikasi Kitosan dari Limbah Udang menggunakan Metode Gelasi Ionik." Journal of Bioprocess, Chemical and Environmental Engineering Science 4, no. 1 (2023): 19–29. https://doi.org/10.31258/jbchees.4.1.19-29.
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Chitin contained in shrimp shells can be used as raw material for making chitosan which is then reprocessed into nanoparticle-sized chitosan which has many benefits. This study aims to synthesize nanoparticle chitosan using the ionic gelation method and determine the effect of variations in the concentration of formic acid, sodium tripolyphosphate (TPP), chitosan, and the volume ratio of chitosan: TPP on particle characteristics, which include particle size, polydispersity index, zeta potential, particle morphology, and functional groups of particles. The first step for making nanoparticle chitosan is to make a chitosan solution using a magnetic stirrer. After that, the TPP solution at a certain volume ratio between chitosan: TPP was added to the chitosan solution. Stirring is carried out for 1 hour with a stirring speed of 1200 rpm. Furthermore, the nanoparticle chitosan was characterized by using Particle Size Analyzer (PSA), zeta potential analyzer, Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red (FTIR). The synthesis of nanoparticle chitosan using the ionic gelation method has been successfully carried out, obtaining a particle size of 464.4 nm, a polydispersity index of 0.214, a zeta potential of +0.48, and a cross-link of chitosan-TPP particles is formed.
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Chung, Ding-Wen, Paul R. Shearing, Nigel P. Brandon, Stephen J. Harris, and R. Edwin García. "Particle Size Polydispersity in Li-Ion Batteries." Journal of The Electrochemical Society 161, no. 3 (2014): A422—A430. http://dx.doi.org/10.1149/2.097403jes.
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Chabib, Lutfi, Fakhrul Hakim Ar Rodli, Bambang Hernawan Nugroho, Arman Suryani, and Ferdy Firmansyah. "Development of nanoliposome formulation of beta-carotene using high speed homogeniser method." Pharmacy Education 24, no. 2 (2024): 1–8. http://dx.doi.org/10.46542/pe.2024.242.18.
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Background: Beta carotene has hydrophobic and unstable properties. Nanoliposomes can package various types of drugs, including hydrophilic and hydrophobic drugs, as well as biological substances such as DNA, RNA, and proteins. This allows for more efficient and targeted drug delivery, making it possible to formulate beta-carotene nanoliposomes to improve efficacy and stability. Objective: To formulate and characterise betacarotene liposomes using high speed homogeniser method and to conduct an accelerated stability test on betacarotene liposomes produced using high speed homogeniser method. Methods: Nanoliposomes were prepared by high speed homogeniser method with time variation of 3, 6, 9 and 12 minutes and characterised for particle size, zeta potential value, polydispersity index, encapsulation efficiency, and stability. Results: The preparation of nanoliposomes produced a yellow, odourless suspension with antioxidant activity, with particle size characteristics measuring 200-300 nm, with a polydispersity index of 0.2-0.5 and potential zeta values ranging from -25 mV to -30 mV, encapsulation efficiency value of 97% and morphology of liposome particles in the form of spherical globules with 500x magnification. Conclusion: Formulation with a time variation of 12 minutes has recommended characteristics with spherical shape having good particle size, polydispersity index value, zeta potential value and encapsulation efficiency value.
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Shi, Ruifang, Jianzhong Lin, and Hailin Yang. "Distribution of Nanoparticles in a Turbulent Taylor–Couette Flow Considering Particle Coagulation and Breakage." Processes 9, no. 10 (2021): 1789. http://dx.doi.org/10.3390/pr9101789.
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In this paper, the dynamic evolution of nanoparticles in a turbulent Taylor–Couette flow was studied by means of a numerical simulation. The initial particle size was 200 nm, and the volume concentration was 1 × 10−5. The Reynolds-averaged N–S equation for Taylor–Couette flow was solved numerically using the realizable k-ε model combined with the standard wall function. The numerical result of the velocity distribution is in good agreement with the experimental results. Additionally, the dynamic equation for the particle number distribution function was solved numerically using the Taylor series expansion moment method (TEMOM). The variation characteristics of particle number density, diameter and polydispersity in the flow were analyzed. The results show that particle breakage is obvious in the region with strong vorticity due to the large shear strength, which leads to a significant change in the particle number density, diameter and polydispersity. Furthermore, the effects of the gap width between two cylinders and the Reynolds number on the distribution of the particle number density, size and polydispersity are discussed.
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Polanía, Oscar, Nicolás Estrada, Mathieu Renouf, Emilien Azéma, and Miguel Cabrera. "Granular column collapse: The role of particle size polydispersity on the velocity and runout." E3S Web of Conferences 415 (2023): 02017. http://dx.doi.org/10.1051/e3sconf/202341502017.
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Geophysical mass flows involve particles of different sizes, a property termed polydispersity. The granular column collapse is a simplified experiment for studying transitional granular flows. Our research focuses on the role that polydispersity has on the velocity and runout distance of dry and immersed granular columns, undergoing a numerical and experimental study. Our results highlight that polydispersity does not have a strong effect on the collapse of dry columns. On the contrary, the collapse sequence of immerse granular columns strongly depend on the polydispersity level.
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Ningsih, Zubaidah, Sepriana Puspita Dewi Syaiful, Maria Lucia A.D. Lestari, Diah Mardiana, and Budi Kamulyan. "Comparison of Fabrication Technique and Carrier Oil to Curcumin Nanoemulsion Properties." Journal of Pure and Applied Chemistry Research 12, no. 1 (2023): 47–56. http://dx.doi.org/10.21776/ub.jpacr.2023.012.01.701.
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Turmeric (Curcuma longa L.) is included in the rhizome plant containing curcumin which has various therapeutic properties. However, curcumin has poor bioavailability. The manufacture of nanoemulsion is expected to increase curcumin bioavailability. This study aims to compare 3 methods (wet-ball milling, ultrasonication and microfluidic) and 3 carrier oils (soybean, virgin coconut, and olive oil) in the production of curcumin nanoemulsion. Wet-ball milling reduces particle size through grinding process using milling beads in liquid medium. Microfluidic decreases the particle size via collision of emulsion components in microchannel while ultrasound utilizes sound-wave energy to break down the particle size. Parameters compared were particle size, polydispersity index and entrapment efficiency. Particle size and polydispersity index were observed using Particle Size Analyzer with Dynamic Light Scattering technique while entrapment efficiency was measured based on the curcumin absorbance in UV-Visible spectrophotometer at 420 nm. Our study concludes that microfluidic is the most effective and efficient fabrication method which produces the smallest particle size and polydispersity index compared to ultrasonication and microfluidic. The resulting particle sizes using microfluidic are 154, 140 and 132 nm with polydispersity index of 0.224; 0.200 and 0.208 in soybean, virgin coconut, and olive oil respectively. However, entrapment efficiency is best achieved using wet-ball milling method with the average value of 49±10%. Soybean oil appears to be the most curcumin solubilizing oil compared to olive and virgin coconut oil. Thus, it can be concluded that fabrication methods and carrier oils determine curcumin nanoemulsion properties.
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Zou, Zhike, Lei Yu, Yalong Li, et al. "The Comparison of Seven Models to Simulate the Transport and Deposition of Polydisperse Particles under Favorable Conditions in a Saturated Medium." Water 15, no. 12 (2023): 2193. http://dx.doi.org/10.3390/w15122193.
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Polydisperse particles are ubiquitous in both the natural and engineered environment, and the precise prediction of the transport and capture of polydisperse particles in a saturated medium is crucial. Several efforts (Yao model, RT model, TE model, MPFJ model, NG model, MHJ model, and MMS model) were developed to obtain accurate correlation equations for the particle capture probability (single-collector removal efficiency), but the applicability of the existing models to the entire porous medium and the retention characteristic of the polydisperse particles are still unclear. In this study, sand column experiments were undertaken to investigate the transport and capture processes of the polydisperse particles in the saturated medium. The mass density was employed to quantize the effects of particle polydispersity and incorporated into the depth-dependent deposition rate. The experimental results showed that the polydisperse particles formed a hyper-exponential retention profile even under favorable conditions (no repulsion). The excellent agreement between the results obtained from the MMS model and the experimentally observed results of the breakthrough curves (BTCs), as well as the retention profiles demonstrated the validation of the MMS model, as the correlation coefficient and the standard average relative error were 0.99 and 0.005, respectively. The hyper-exponential retention profile is caused by the uneven capture of the polydisperse particles by the porous medium. This study highlights the influences of particle polydispersity on particle transport and capture in a saturated porous medium.
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Ekasari, Munifilia, Devi Nurhasana, Andre Mudyanto, Avidlyandi Avidlyandi, Charles Banon, and Morina Adfa. "AKTIVITAS ANTIJAMUR PELAPUK KAYU NANOPARTIKEL KITOSAN-EKSTRAK N-HEKSAN DAGING BUAH KAYU GADIS (Cinnamomum parthenoxylon)." Jurnal Biosilampari : Jurnal Biologi 5, no. 2 (2023): 214–25. http://dx.doi.org/10.31540/biosilampari.v5i2.2401.
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This study aims to synthesize chitosan nanoparticles - n-hexane extract of Cinnamomum parthenoxylon (CP) fruit using the ionic gelation method, to characterize them, and to determine their antifungal activity against the wood-rotting fungi Trametes versicolor and Fomitopsis palustris. Chitosan-CP extract nanoparticles were formulated with chitosan:Na-TPP:CP extract ratio of 1:1:0.5. Particle size and polydispersity index were determined using a particle size analyzer (PSA), and particles morphology was observed using a scanning electron microscope (SEM), and antifungal activity was measured using agar media. The results revealed that the average size of chitosan nanoparticles (base) was 276.9 nm, while the average size of chitosan-CP extract nanoparticles was 807.6 nm. The polydispersity index (PI) of both nanoparticles was greater than 0.7. Observations of the nanoparticles' morphology revealed that aggregation/agglomeration formed in the resulting particles. Both nanoparticles chitosan (base) and chitosan-CP extract inhibited the growth of white rot fungi (T. versicolor) more than brown rot fungi (F. palustris), as measured by the inhibitory zone.
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Pusey, P. N., E. Zaccarelli, C. Valeriani, E. Sanz, Wilson C. K. Poon, and Michael E. Cates. "Hard spheres: crystallization and glass formation." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, no. 1909 (2009): 4993–5011. http://dx.doi.org/10.1098/rsta.2009.0181.
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Motivated by old experiments on colloidal suspensions, we report molecular dynamics simulations of assemblies of hard spheres, addressing crystallization and glass formation. The simulations cover wide ranges of polydispersity s (standard deviation of the particle size distribution divided by its mean) and particle concentration. No crystallization is observed for s >0.07. For 0.02< s <0.07, we find that increasing the polydispersity at a given concentration slows down crystal nucleation. The main effect here is that polydispersity reduces the supersaturation since it tends to stabilize the fluid but to destabilize the crystal. At a given polydispersity (<0.07), we find three regimes of nucleation: standard nucleation and growth at concentrations in and slightly above the coexistence region; ‘spinodal nucleation’, where the free-energy barrier to nucleation appears to be negligible, at intermediate concentrations; and, at the highest concentrations, a new mechanism, still to be fully understood, which only requires small rearrangement of the particle positions. The cross-over between the second and third regimes occurs at a concentration, approximately 58 per cent by volume, where the colloid experiments show a marked change in the nature of the crystals formed and the particle dynamics indicate an ‘ideal’ glass transition.
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Faivre-Moskalenko, Cendrine, Julien Bernaud, Audrey Thomas, et al. "RNA Control of HIV-1 Particle Size Polydispersity." PLoS ONE 9, no. 1 (2014): e83874. http://dx.doi.org/10.1371/journal.pone.0083874.
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Wadhi, Maria Nuari Putri, Ilham Kuncahyo, and Ismi Rahmawati. "Optimization of Self Nanoemulsifying Drug Delivery System of Mature Green Betel Leaf Fraction with D-Optimal Method and Antifungal Activity of Candida albicans." Formosa Journal of Multidisciplinary Research 4, no. 2 (2025): 881–98. https://doi.org/10.55927/fjmr.v4i2.79.
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The purpose of the study was to see the most active fraction in providing activity, the influence and optimal proportion of oleic acid, tween 80, and propylene glycol on characterization and the optimal formula that has increased activity. The Fractionation Process uses water, ethyl acetate, and n-hexane as solvents. Activity tests use concentration variations of 0.4%, 0.8%, 1.6%. SNEDDS formulation uses 15% -20% oleic acid, 55% -60% tween 80, and 20% -25% propylene glycol and is tested for characterization and optimization using D-optimal. The optimum formula was tested for antifungal activity. The results of the antifungal activity test showed that the ethyl acetate fraction had the most active activity. Characterization showed that an increase in oleic acid provided an increase in emulsification time, particle size, polydispersion index, zeta potential and a decrease in drug loading. The increase of tween 80 and propylene glycol resulted in a decrease in emulsification time, particle size, polydispersity index, zeta potential, and an increase in drug loading. The optimum formula at the ratio of oleic acid: tween 80:propylene glycol = 16.1:58.9:25 with an emulsification time of 70 seconds, particle size of 186.98, polydispersity index of 0.331, zeta potential of -32.02, and drug loading of 74.3%. The optimum formula resulted in an increase in DDH of 1.3 mm.
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Widyaningrum, Ike, Efriza Fahmi Triyoga, Nugroho Wibisono, Shinta Kusumawati, and Anita Puspa Widiyana. "Type of Cosurfactant Effects on Particle Size in Nanoemulsion Drug Delivery Systems." East Asian Journal of Multidisciplinary Research 2, no. 9 (2023): 3811–20. http://dx.doi.org/10.55927/eajmr.v2i9.6276.
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Nanoemulsions are thermodynamically or kinetically stable compared to conventional emulsions, and the particle size of nanoemulsions is around 5-200 nm. Until now, there has been no research comparing propylene glycol and PEG 400 cosurfactants for nanoemulsions, so it needs to be investigated. Laboratory experimental research with cosurfactant propylene glycol and PEG 400 Formula 1 and Formula 2 were repeated three times (n = 3) for each nanoemulsion formula. Parameters of physical properties (organoleptic, viscosity, particle size, index polydispersity) and chemical properties (pH). Evaluated and analyzed, <0.05 is considered significant. The results of formula 1 and formula 2 obtained the same clear organoleptic properties. The average particle size with cosurfactant propylene glycol was 10.41 ± 0.14 nm and PEG 400 was 12.32 ± 0.38 nm (p <0.05). The average viscosity, polydispersity index, and pH of propylene glycol were 8.72 ± 1.12; 0.03±0.02; 4.20 ± 0.04; and PEG 11.26 ± 1.80; 0.39 ± 0.58; 4.03±0.03. This shows that the type of cosurfactant has an effect on the size of the nanoemulsion particles.
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Şimşek, Barış, Gözde Ultav, Haluk Korucu, and Ahmet Yartaşı. "Improvement of the Graphene Oxide Dispersion Properties with the Use of TOPSIS Based Taguchi Application." Periodica Polytechnica Chemical Engineering 62, no. 3 (2018): 323–35. http://dx.doi.org/10.3311/ppch.11412.
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The stability of the graphene oxide dispersions is an important issue in the preparation of medicine, printed flexible electronics, 3D printers and conductive inks. In order to improve the stability; mean and standard deviation of particle size, polydispersity index, zeta potential and conductivity of graphene oxide dispersion were selected as the main stability properties. The improvement rate between the estimate and the optimal conditions were calculated for the mean and standard deviation of particle size, polydispersity index, zeta potential and conductivity as 264.0%, 1875.0%, 583.3%, 5.0% and 50.0%, respectively in terms of the GO quality characteristics. The improvement rate between the estimate and the optimal conditions were calculated for the mean and standard deviation of particle size, polydispersity index, zeta potential and conductivity as 42.7%, 79.7%, -5.0%, 9.9% and -86.7%, respectively in terms of the GO quality characteristics. The result show that TOPSIS based Taguchi optimization in this study is effective to improve the graphene oxide dispersion stability.
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Skenderović, Ivan, Gregor Kotalczyk, and Frank Kruis. "Dual Population Balance Monte Carlo Simulation of Particle Synthesis by Flame Spray Pyrolysis." Processes 6, no. 12 (2018): 253. http://dx.doi.org/10.3390/pr6120253.
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The Dual Population Balance Monte Carlo Method (DPBMC) takes into account the full size spectrum of the droplet and particle phase. Droplet and particle size distributions are rendered by weighted simulation particles. This allows for an accurate description of particle nucleation and coagulation and droplet combustion, simultaneously. Internal droplet properties such as temperature and concentrations fields are used to define criteria for the onset of droplet breakage in the framework of weighted Monte Carlo droplets. We discuss the importance of droplet polydispersity on particle formation in metal oxide particle synthesis, which is shown to strongly affect particle formation and growth. The method is applied to particle synthesis from metal nitrate precursor solutions with flame spray pyrolysis (FSP) and compared to experiments from literature.
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Yuan, Ye, Wei Deng, and Shuixiang Li. "Structural universality in disordered packings with size and shape polydispersity." Soft Matter 16, no. 18 (2020): 4528–39. http://dx.doi.org/10.1039/d0sm00110d.
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Iannotti, Vincenzo, Giovanni Ausanio, Anna M. Ferretti, et al. "Magnetic Response of Nano/Microparticles into Elastomeric Electrospun Fibers." Journal of Functional Biomaterials 14, no. 2 (2023): 78. http://dx.doi.org/10.3390/jfb14020078.
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Combining magnetic nanoparticles (MNPs) with high-voltage processes to produce ultra-thin magnetic nanofibers (MNFs) fosters the development of next-generation technologies. In this study, polycarbonate urethane nanofibers incorporating magnetic particles were produced via the electrospinning technique. Two distinct types of magnetic payload were used: (a) iron oxide nanoparticles (IONPs) with an average size and polydispersity index of 7.2 nm and 3.3%, respectively; (b) nickel particles (NiPs) exhibiting a bimodal size distribution with average sizes of 129 nanometers and 600 nanometers, respectively, and corresponding polydispersity indexes of 27.8% and 3.9%. Due to varying particle sizes, significant differences were observed in their aggregation and distribution within the nanofibers. Further, the magnetic response of the IONP and/or NiP-loaded fiber mats was consistent with their morphology and polydispersity index. In the case of IONPs, the remanence ratio (Mr/Ms) and the coercive field (Hc) were found to be zero, which agrees with their superparamagnetic behavior when the average size is smaller than 20–30 nm. However, the NiPs show Mr/Ms = 22% with a coercive field of 0.2 kOeas expected for particles in a single or pseudo-single domain state interacting with each other via dipolar interaction. We conclude that magnetic properties can be modulated by controlling the average size and polydispersity index of the magnetic particles embedded in fiber mats to design magneto-active systems suitable for different applications (i.e., wound healing and drug delivery).
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Hoh, Nicholas J., and Roseanna N. Zia. "The impact of probe size on measurements of diffusion in active microrheology." Lab on a Chip 16, no. 16 (2016): 3114–29. http://dx.doi.org/10.1039/c6lc00476h.
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A framework to study the influence of polydispersity on flow-induced diffusion in active microrheology is presented. It is found that diffusive behavior is set entirely and dually by the proximity with which two particles can approach one another, and by the extent to which this minimum approach distance is occupied by the hydrodynamic size of the forced particle.
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ITO, NOBUYASU. "POLYDISPERSITY EFFECT TO THE FLUID-SOLID TRANSITION." International Journal of Modern Physics C 07, no. 03 (1996): 275–80. http://dx.doi.org/10.1142/s012918319600020x.
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The simulation results for polydisperse particle system are analyzed to study the polydispersity effect to liquid/fluid-solid transition. It is found that the transition density and the solid state are well described by the variance, σ2, of radius distribution. The critical polydispersity above which fluid-solid coexisting density region vanishes is estimated to be σ2 = 0.0073 ± 0.0005. A scaling plot for the solid pressure is shown.
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Dzakwan, Muhammad, Eko Pramukantoro Ganet, Mauludin Rachmat, and Saleh Wikarsa. "Nanosized and Enhancement of Solubility Fisetin." Asian Journal of Pharmaceutical Research and Development 7, no. 2 (2019): 6–10. http://dx.doi.org/10.22270/ajprd.v7i2.465.
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Fisetin (3,3,4,7-tetrahydroxyflavone) is a natural antioxidant that has shown to posses anticancer, antioxidant and anti-inflammatory properties. However, the poor solubility leads to poor bioavailability and limits its development.The aim of the research is to investigate the effect of fisetin nanosuspension using a nanoprecipitation technique and additional stabilizers polysorbat 80, SLS, PVA and Eudragit on particle size average, polydispersity index and zeta potential.The suspensions of microcrystalline FIS were prepared by a nanoprecipitation technique with different proportion of stabilizers fixed. The nanosuspension produced was then characterized using Photon Correlation Spectroscopy (PCS) in term of particle size distribution, polydispersity index, zeta potential and morphology nanosuspensiom (TEM). Result showed fisetin nanosuspension were successfully prepared by anti-solvent precipitation with additional stabilizer SLS and polysorbat 80. The nanosuspension containing polysorbat 80 showed smaller average particle size of 225.7 nm ± 1.31, a polydispersity index of 0.272 ±0.02 and zeta potential -39.3 ± 0.26 was obtained. Conclusion, FIS nanosuspension successfully prepared by nanoprecipitation tecnique with the polysorbate 80 as stabilizer and ethanol as solvent were spherical in shape..
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TAO, R. "THE PHYSICAL MECHANISM TO REDUCE VISCOSITY OF LIQUID SUSPENSIONS." International Journal of Modern Physics B 21, no. 28n29 (2007): 4767–73. http://dx.doi.org/10.1142/s0217979207045645.
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Reducing the viscosity of liquid suspensions is vital in science and engineering. This paper explores the physical mechanism for the viscosity reduction method in liquid suspension by pulsed electric or magnetic field. The key is that the maximum volume fraction to be available for the suspended particles in the suspension increases with the particle size and the polydispersity in the particle size distribution. Positive experimental results with various liquid suspensions indicate that this method, developed from the basic mechanism of viscosity, is universal and powerful for all liquid suspensions with broad applications.
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Ludek, Sylwia, Agata Wawrzyńczak, Izabela Nowak, and Agnieszka Feliczak-Guzik. "Synthesis of Lipid Nanoparticles Incorporated with Ferula assa-foetida L. Extract." Cosmetics 9, no. 6 (2022): 129. http://dx.doi.org/10.3390/cosmetics9060129.
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Solid Lipid Nanoparticles (SLN) have been prepared by high-pressure homogenization and optimized in order to protect ferulic acid from Ferula assa-foetida L. extract. The influence of lipid and surfactant concentration on the mean particle size (Z-Ave), polydispersity index (PDI), and zeta potential (ZP) of SLN was analyzed. In addition, other parameters for the preparation of ferulic acid-loaded nanoparticles, such as extract concentration and variable parameters for the synthesis method used (e.g., pressure), were adjusted to obtain the smallest particle size and polydispersity index, as well as the highest value for zeta potential, which are characteristic of the stable SLN. The established formulation obtained from the optimized synthesis was composed of 6.0 wt.% of the lipid phase and 1.5 wt.% of surfactant, giving stable SLN with Z-Ave, PDI, and ZP values of 163.00 ± 1.06 nm, 0.16 ± 0.01, and −41.97 ± 0.47 mV, respectively. The loading of ferulic acid from Ferula assa-foetida L. extract within the SLN resulted in particles with a mean size of 155.3 ± 1.1 nm, polydispersity index of 0.16 ± 0.01, zeta potential of −38.00 ± 1.12 mV, and encapsulation efficiency of 27%, the latter being quantified on the basis of RP-HPLC analysis. Our findings highlight the added value of SLN as a delivery system for phenolic phytochemical compounds extracted from Ferula assa-foetida L.
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Guarnieri, João Paulo de Oliveira, Bruno Gaia Bernardes, Carlos Fernando Macedo da Silva, et al. "Optimization process of vaccine production of outer membrane vesicle from Neisseria meningitidis associated with Zika virus." Research, Society and Development 12, no. 4 (2023): e25912441268. http://dx.doi.org/10.33448/rsd-v12i4.41268.
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Several vaccine prototypes were made using variations in concentration, volume, time and speed of agitation. From these prototypes, some characterization assays were carried out, such as the analysis of particle size and zeta potential, where it was possible to determine the size of the nanoparticles, the polydispersity index, with the most promising samples having a size of 252.1nm ± 71.2 nm. The polydispersity index was 0.572 ±0.02, the standard deviation being a little high due to the presence of free viral particles and some associated vesicles. It is noteworthy that the isolated vesicle has a size of 140 to 160nm and the polydispersity index of 0.513 demonstrates that we do not have interference in the sample of our vesicle (it is known that the size of the viral particle of Zika virus is between 40 and 60nm). Cytotoxicity testing was done to analyze whether they have cytotoxic profiles and also demonstrate that the prototype's neutralization and inactivation method works correctly. The analysis of the protein profile of some of the samples revealed that there are two major Zika virus proteins in the fused proteasome, namely the E protein, which is directly involved in the recognition of host cell receptors, and the C protein, which is related to capsid assembly, in addition to playing an important role in the immune response.
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Azizi, Itay, and Yitzhak Rabin. "Systems with Size and Energy Polydispersity: From Glasses to Mosaic Crystals." Entropy 22, no. 5 (2020): 570. http://dx.doi.org/10.3390/e22050570.
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We use Langevin dynamics simulations to study dense 2d systems of particles with both size and energy polydispersity. We compare two types of bidisperse systems which differ in the correlation between particle size and interaction parameters: in one system big particles have high interaction parameters and small particles have low interaction parameters, while in the other system the situation is reversed. We study the different phases of the two systems and compare them to those of a system with size but not energy bidispersity. We show that, depending on the strength of interaction between big and small particles, cooling to low temperatures yields either homogeneous glasses or mosaic crystals. We find that systems with low mixing interaction, undergo partial freezing of one of the components at intermediate temperatures, and that while this phenomenon is energy-driven in both size and energy bidisperse systems, it is controlled by entropic effects in systems with size bidispersity only.
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LIN, JIAN-ZHONG, and YU-MING WANG. "EFFECTS OF INTER-PARTICLE INTERACTIONS AND HYDRODYNAMICS ON THE BROWNIAN COAGULATION RATE OF POLYDISPERSE NANOPARTICLES." Modern Physics Letters B 26, no. 03 (2012): 1150010. http://dx.doi.org/10.1142/s0217984911500102.
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The Brownian coagulation rate of polydisperse nanoparticles by considering the effects of inter-particle interactions and hydrodynamics is studied in the gas-slip regime. The collision efficiency before and after particle contact is calculated by considering the van der Waals force, electrical repulsion, electrostatic force and elastic deformation force, respectively. It is found that the total collision efficiency decreases with the increase of both particle diameter and particle size ratio. Based on the total collision efficiency, the coagulation rate of polydisperse nanoparticles with considering the effects of inter-particle interactions and hydrodynamics is calculated. The results show that the coagulation rate with considering such effects is closer to the experimental data and much smaller than that without considering the effects. The inter-particle interactions and hydrodynamics make particles more difficult to coagulate and cause the coagulation rate to become weaker when the Knudsen number increases. The particles with high polydispersity coagulate more easily.
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Davis, Robert H., and Mark A. Hassen. "Spreading of the interface at the top of a slightly polydisperse sedimenting suspension." Journal of Fluid Mechanics 196 (November 1988): 107–34. http://dx.doi.org/10.1017/s0022112088002630.
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The interface at the top of a dilute sedimenting suspension of small particles which are not identical does not remain sharp but instead becomes increasingly diffuse as the sedimentation proceeds. For more concentrated suspensions, the self-sharpening effect of hindered settling leads to a considerable reduction in the observed spreading of the sedimenting interface. In order to quantify this spreading, a light extinction technique was used to measure the concentration profile in the interface of a suspension of particles with a small spread of sizes as it fell past a thin sheet of light. A particle volume-fraction range of 0.002 ≤ Φ0 ≤ 0.15 was examined, and each fluid-particle system had a particle Reynolds number less than 10−3 and a Péclet number greater than 107 so that inertia and colloidal effects were negligible. Calculations of the spreading arising from the small degree of polydispersity in particle sizes and the self-sharpening effect are presented. Surprisingly, the measured vertical thickness of the interface was found to be several times that predicted from this theory.It is proposed that the observed spreading may be attributed to hydrodynamic interactions between particles that lead to fluctuations in particle settling velocities about the mean. An analysis of the data shows that the measured interface thickness, after subtracting off that predicted from polydispersity and self-sharpening, increases approximately with the square root of the settling distance and may therefore be described as a diffusion process, termed ‘self-induced hydrodynamic diffusion’. By sealing the hydrodynamic diffusivity as $D = au_{\frac{1}{2}}\hat{D}(\Phi_0)$, where u½ is the median hindered settling velocity, a is the median particle radius, and Φ0 is the volume fraction of particles well below the interface, an approximate analysis of the data was used to infer that the dimensionless scaled diffusion coefficient, $\hat{D}$, is between 1 and 2 for the smaller particle volume fractions examined, increases very rapidly with increasing concentration to a value between 10 and 15 for particle concentrations of a few percent by volume, and then levels off or declines slightly as the particle concentration is increased further.
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Foley, Greg, Dermot M. Malone, and Frank MacLoughlin. "Modelling the effects of particle polydispersity in crossflow filtration." Journal of Membrane Science 99, no. 1 (1995): 77–88. http://dx.doi.org/10.1016/0376-7388(94)00207-f.
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Liu, Shang-Hao, Yang-Fan Cheng, Xiang-Rui Meng, et al. "Influence of particle size polydispersity on coal dust explosibility." Journal of Loss Prevention in the Process Industries 56 (November 2018): 444–50. http://dx.doi.org/10.1016/j.jlp.2018.10.005.
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Stribeck, Norbert. "Analysis of scattering from polydisperse structure using Mellin convolution." Journal of Applied Crystallography 39, no. 2 (2006): 237–43. http://dx.doi.org/10.1107/s0021889806003979.
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This study extends a mathematical concept for the description of heterogeneity and polydispersity in the structure of materials to multiple dimensions. In one dimension, the description of heterogeneity by means of Mellin convolution is well known. In several papers by the author, the method has been applied to the analysis of data from materials with one-dimensional structure (layer stacks or fibrils along their principal axis). According to this concept, heterogeneous structures built from polydisperse ensembles of structural units are advantageously described by the Mellin convolution of a representative template structure with the size distribution of the templates. Hence, the polydisperse ensemble of similar structural units is generated by superposition of dilated templates. This approach is particularly attractive considering the advantageous mathematical properties enjoyed by the Mellin convolution. Thus, average particle size, and width and skewness of the particle size distribution can be determined from scattering data without the need to model the size distributions themselves. The present theoretical treatment demonstrates that the concept is generally extensible to dilation in multiple dimensions. Moreover, in an analogous manner, a representative cluster of correlated particles (e.g.layer stacks or microfibrils) can be considered as a template on a higher level. Polydispersity of such clusters is, again, described by subjecting the template structure to the generalized Mellin convolution. The proposed theory leads to a simple pathway for the quantitative determination of polydispersity and heterogeneity parameters. Consistency with the established theoretical approach of polydispersity in scattering theory is demonstrated. The method is applied to the best advantage in the field of soft condensed matter when anisotropic nanostructured materials are to be characterized by means of small-angle scattering (SAXS, USAXS, SANS).
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Rahmani, M., G. Geraci, G. Iaccarino, and A. Mani. "Effects of particle polydispersity on radiative heat transfer in particle-laden turbulent flows." International Journal of Multiphase Flow 104 (July 2018): 42–59. http://dx.doi.org/10.1016/j.ijmultiphaseflow.2018.03.011.
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Ayrancı, Işıl, Guillaume Pinguet, Dany Escudié, Nevin Selçuk, Rodolphe Vaillon, and Frédéric André. "Effect of particle polydispersity on particle concentration measurement by using laser Doppler anemometry." Experimental Thermal and Fluid Science 31, no. 8 (2007): 839–47. http://dx.doi.org/10.1016/j.expthermflusci.2006.03.031.
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Betala, Surendranath, M. Mohan Varma, and K. Abbulu. "Formulation and evaluation of polymeric nanoparticles of an antihypetensive drug for gastroretention." Journal of Drug Delivery and Therapeutics 8, no. 6 (2018): 82–86. http://dx.doi.org/10.22270/jddt.v8i6.2018.
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The aim of present study was to formulate and evaluate nanoparticles of carvedilol by using different hydrophilic polymers. Carvedilol was selected as a suitable drug for gastro- retentive nanoparticles due to its short half life, low bioavailability, high frequency of administration, and narrow absorption window in stomach and upper part of GIT. The nano-precipitation method was used to prepare nanoparticles so as to avoid both chlorinated solvents and surfactants to prevent their toxic effect on the body. Nanoparticles of carvedilol were prepared by using hydrophilic polymers such as HPMC K100M, chitosan, and gelatin. The prepared formulations were then characterized for particle size, polydispersity index, zeta potential, loading efficiency, encapsulation efficiency and drug-excipient compatibility. The prepared nanoparticulate formulations of carvedilol with different polymers in 1:1 ratio have shown particle size in the range of 250.12-743.07 nm, polydispersity index (PDI) in the range of 0.681-1.0, zeta potential in the range of -14.2 to +33.2 mV, loading efficiency in the range of 8.74-17.54%, and entrapment efficiency in the range of 55.7%-74.2%. Nanoparticulate formulation prepared with chitosan in 1:1 ratio showed satisfactory results i.e. average particle size 312.04 nm, polydispersity index 0.681, zeta potential 33.2 mV, loading efficiency 17.54%, and entrapment efficiency 73.4%. FTIR study concluded that no major interaction occurred between the drug and polymers used in the present study.
 Keywords: Nanoparticles; gastro-retentive; nano-precipitation, polydispersity index, zeta potential; entrapment efficiency.
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Domínguez-Delgado, Clara Luisa, Zubia Akhtar, Godfrey Awuah-Mensah, Braden Wu, and Hugh David Charles Smyth. "Effects of Process and Formulation Parameters on Submicron Polymeric Particles Produced by a Rapid Emulsion-Diffusion Method." Nanomaterials 12, no. 2 (2022): 229. http://dx.doi.org/10.3390/nano12020229.
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Emulsification-diffusion method is often used to produce polymeric nanoparticles. However, their numerous and/or lengthy steps make it difficult to use widely. Thus, a modified method using solvent blends (miscible/partially miscible in water, 25–100%) as the organic phases to overcome these disadvantages and its design space were investigated. To further simplify the process, no organic/aqueous phase saturation and no water addition after the emulsification step were performed. Biodegradable (PLGA) or pH-sensitive (Eudragit® E100) nanoparticles were robustly produced using low/medium shear stirring adding dropwise the organic phase into the aqueous phase or vice versa. Several behaviors were also obtained: lowering the partially water-miscible solvent ratio relative to the organic phase or the poloxamer-407 concentration; or increasing the organic phase polarity or the polyvinyl alcohol concentration produced smaller particle sizes/polydispersity. Nanoparticle zeta potential increased as the water-miscible solvent ratio increased. Poloxamer-407 showed better performance to decrease the particle size (~50 nm) at low concentrations (≤1%, w/v) compared with polyvinyl alcohol at 1–5% (w/v), but higher concentrations produced bigger particles/polydispersity (≥600 nm). Most important, an inverse linear correlation to predict the particle size by determining the solubility parameter was found. A rapid method to broadly prepare nanoparticles using straightforward equipment is provided.
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Suhawati, Ibrahim, and Asrul Mustafa. "Chemical Depolymerisation of Natural Rubber in Biphasic Medium." Advanced Materials Research 1024 (August 2014): 193–96. http://dx.doi.org/10.4028/www.scientific.net/amr.1024.193.
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The molecular weight of natural rubber (NR) can be reduced via depolymerization reaction to produce liquid natural rubber (LNR) with a molecular weight less than 50 000 g/mol. In the reaction, hydrogen peroxide and sodium nitrite were added to natural rubber latex to initiate a redox type reaction which then breaks the NR chain. Low permeation of reagents into latex particles allows the degradation to occur greater at the latex particle surface relative to the inner core contributes to high molecular weight distribution (MWD) or polydispersity of the LNR obtained. In this recent works, the reaction was carried out in a biphasic medium consisting of water and toluene phases. Toluene swells latex particles as indicated by the SEM micrographs showing changes in the size of latex particles. This occurrence is suggested to increase the influx of reagents into the latex particles. Consequently, with higher permeation of reagents into the latex particles resulted in the decrease of molecular weight and lower polydispersity of the LNR obtained. Chemical structure analysize showed that the LNRs obtained were attached with hydroxyl and carbonyl groups.
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Tefas, Lucia Ruxandra, Ioan Tomuță, Marcela Achim, and Laurian Vlase. "Development and optimization of quercetin-loaded PLGA nanoparticles by experimental design." Medicine and Pharmacy Reports 88, no. 2 (2015): 214–23. http://dx.doi.org/10.15386/cjmed-418.
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Background and aims: Quercetin is a flavonoid with good antioxidant activity, and exhibits various important pharmacological effects. The aim of the present work was to study the influence of formulation factors on the physicochemical properties of quercetin-loaded polymeric nanoparticles in order to optimize the formulation.Materials and methods: The nanoparticles were prepared by the nanoprecipitation method. A 3-factor, 3-level Box-Behnken design was employed in this study considering poly(D,L-lactic-co-glycolic) acid (PLGA) concentration, polyvinyl alcohol (PVA) concentration and the stirring speed as independent variables. The responses were particle size, polydispersity index, zeta potential and encapsulation efficiency.Results: The PLGA concentration seemed to be the most important factor influencing quercetin-nanoparticle characteristics. Increasing PLGA concentration led to an increase in particle size, as well as encapsulation efficiency. On the other hand, it exhibited a negative influence on the polydispersity index and zeta potential. The PVA concentration and the stirring speed had only a slight influence on particle size and polydispersity index. However, PVA concentration had an important negative effect on the encapsulation efficiency. Based on the results obtained, an optimized formulation was prepared, and the experimental values were comparable to the predicted ones.Conclusions: The overall results indicated that PLGA concentration was the main factor influencing particle size, while entrapment efficiency was predominantly affected by the PVA concentration.
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Plumeré, Nicolas, Adrian Ruff, Bernd Speiser, Verena Feldmann, and Hermann A. Mayer. "Stöber silica particles as basis for redox modifications: Particle shape, size, polydispersity, and porosity." Journal of Colloid and Interface Science 368, no. 1 (2012): 208–19. http://dx.doi.org/10.1016/j.jcis.2011.10.070.
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Choudhary, Priyanka, K. C. Patel, Praveen Singh, et al. "Green Synthesis of Sulphur Nanoparticles Using Azadirachta indica (Neem Leaf) and Its Characterization." International Journal of Plant & Soil Science 35, no. 23 (2023): 441–48. http://dx.doi.org/10.9734/ijpss/2023/v35i234260.
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Nanoscience has found various applications in different biomedical fields. The synthesis of nanoparticles (NPs) has become a vast area of research due to its potential applications. These particles can be prepared by different chemical, physical and biological approaches. In recent years, green synthesis of NPs using plant extracts has gained much interest due to non-toxicity and very low cost of synthesis. The plant extracts act both as reducing or stabilizing agent as well as capping agent. Neem (Azadirachta indica A. Juss) is a well-known medicinal plant and has been studied for the biosynthesis of NPs. A. indica has various phytochemicals identified that can reduce the metal ions. The bio reduction of NPs from neem extract is an eco-friendly, low cost and green synthesis method. These NPs are reported to exhibit good antimicrobial, mainly antibacterial activity. NPs was characterized by Dynamic Light Scattering (DLS) for particle size, particle size distribution, poly- dispersity index, zeta potential, UV visible spectrophotometer and Fourier-Transform Infrared Spectroscopy (FT-IR) for functional characteristics. Dynamic light scattering measurements for particle size (nm) and Polydispersity Index showed that the particle size was in the range of 35-40 nm with Polydispersity Index of 0.280-0.290, it is the mid-range value and indicating that the particles were in disperse form in aqueous suspension. From the analysis, the zeta potential value was found to be (-5.77 mV), revealing the better stability of synthesized sulphur nanoparticles in aqueous suspension. The FT-IR spectrum showed characteristic absorption of wavenumber from 3384.73 cm-1 and 533.56 cm-1. The absorption spectra of UV-visible spectrophotometer in between the range of 200-800 nm.
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Liu, Wan-Yi, Chia-Chen Lin, Yun-Shan Hsieh, and Yu-Tse Wu. "Nanoformulation Development to Improve the Biopharmaceutical Properties of Fisetin Using Design of Experiment Approach." Molecules 26, no. 10 (2021): 3031. http://dx.doi.org/10.3390/molecules26103031.
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This study aimed to design an effective nanoparticle-based carrier for the oral delivery of fisetin (FST) with improved biopharmaceutical properties. FST-loaded nanoparticles were prepared with polyvinyl alcohol (PVA) and poly(lactic-co-glycolic acid) (PLGA) by the interfacial deposition method. A central composite design of two independent variables, the concentration of PVA and the amount of PLGA, was applied for the optimization of the preparative parameter. The responses, including average particle size, polydispersity index, encapsulation efficiency, and zeta potential, were assessed. The optimized formulation possessed a mean particle size of 187.9 nm, the polydispersity index of 0.121, encapsulation efficiency of 79.3%, and zeta potential of −29.2 mV. The morphological observation demonstrated a globular shape for particles. Differential scanning calorimetry and powder X-ray diffraction studies confirmed that the encapsulated FST was presented as the amorphous state. The dissolution test indicated a 3.06-fold increase for the accumulating concentrations, and the everted gut sac test showed a 4.9-fold gain for permeability at the duodenum region. In conclusion, the optimized FST-loaded nanoparticle formulation in this work can be developed as an efficient oral delivery system of FST to improve its biopharmaceutic properties.
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Setyawati, Damai Ria, Silvia Surini, and Etik Mardliyati. "OPTIMIZATION OF LUTEOLIN-LOADED TRANSFERSOME USING RESPONSE SURFACE METHODOLOGY." International Journal of Applied Pharmaceutics 9 (October 30, 2017): 107. http://dx.doi.org/10.22159/ijap.2017.v9s1.64_71.
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Objective: This research was carried out to optimize luteolin-loaded transfersome formula with independent variables such as lipid–surfactant (totallipid) concentration and luteolin concentration.Methods: Luteolin-loaded transfersome was optimized by response surface methodology based on four parameters, namely, particle size (Z-average),polydispersity index, zeta potential, and entrapment efficiency. The transfersome formula was prepared using central composite design, and theselected independent variables were the total lipid (mixture of phospholipid and Tween 80) and luteolin concentrations. 14 formulas of luteolinloadedtransfersome were prepared by thin film hydration, followed by the sonication method.Results: The total lipid and luteolin concentration significantly affected the entrapment efficiency only. The other parameters were not affected by achange in these variables. The optimum formula of 4.88% total lipid and 0.5% luteolin with desirability value of 0.609 conformed with the predictionparameters. Vesicle imaging using transmission electron microscopy revealed spherical particles and the occurrence of particle aggregation. Theoptimum formula of luteolin-loaded transfersome possessed the following characteristics: Particle size of 286.03±8.46 nm, polydispersity indexof 0.480±0.013, zeta potential of -18.67±0.379 mV, and entrapment efficiency of 94.97±0.28 %. However, these values did not correspond to thepredicted values and were confirmed by the low adjusted and predicted R-squared values.Conclusion: This method can be applied to optimize the entrapment efficiency, and in the future, it can be used for further optimizing formula oftransfersome by including more variables.
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Mohammadi, Farhad, Alireza Moradi, Fatemeh Tavakoli, Samaneh Rahmati, Rashin Giti, and Vahid Ramezani. "Development and characterization of a copolymeric micelle containing soluble and insoluble model drugs." PLOS ONE 18, no. 5 (2023): e0286251. http://dx.doi.org/10.1371/journal.pone.0286251.
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Objectives Micelles are nano-sized particles with a core-shell structure that are made by natural or synthetic polymers or copolymers. The aim of this study was to develop and characterize a copolymeric micelle using two polymers loaded with hydrophilic and lipophilic drugs. Methods Poly(ethylene glycol) and poly(ε-caprolactone) (PEG-PCL) were used to form a copolymeric micelle which was further loaded with either moxifloxacin or clarithromycin as hydrophilic and lipophilic drug samples, respectively. Characterization tests were done including fourier transform-infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, encapsulation efficiency, particle size, zeta potential, polydispersity index, transmission electron microscopy, and in-vitro release test. Results The construction of the copolymer was confirmed by the results of FT-IR and 1H NMR spectroscopy tests. The encapsulation efficiency test exhibited that loading was about 50% for twelve formulations. Particle size, zeta potential, polydispersity index, and transmission electron microscopy confirmed the formation of monodispersed, uniform, and nano-sized micelles with a few negative charges. The kinetic model of release was fitted to the Higuchi model. Conclusions Polymeric micelles consisting of PEG-PCL copolymer were loaded with adequate concentrations of hydrophilic (moxifloxacin) and lipophilic (clarithromycin) model drugs, with a mean particle size under 300 nm. Therefore, copolymeric micelles can be used as a suitable drug delivery system for mucous membranes and skin.
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WANG, CHANGBIN, SHUJIE ZHI, ZHANHONG WAN, ZHILIN SUN, and HAI DING. "NUMERICAL SIMULATION OF ULTRAFINE PARTICLE-LADEN CYLINDER WAKE FLOW WITH COHERENT STRUCTURES." Modern Physics Letters B 23, no. 03 (2009): 529–32. http://dx.doi.org/10.1142/s0217984909018825.
Full textAbstract:
The phenomena of the wake flows containing ultrafine particles such as dust and pollutant in the atmosphere are usually observed downwind of the mountains and buildings. Different from the usually heavy particles, the ultrafine particles suspended in fluid undergo the processes of nucleation, growth and coagulation. Coherent structure in typical occurrence of the stretching of the Karman vortex street can be clearly seen in above mentioned gas-particle wakes. The aim of the present study is to explore the effects of coherent structures on the coagulation and growth of ultrafine particles suspended in wake flow. The particle field is represented by employing a moment method to approximate the ultrafine particle general dynamic equation. The fluid flow is obtained by solving the continuity and momentum equations with the large eddy simulation method and the subgrid-scale stresses were parametrized using the dynamic eddy viscosity model. The calculated contours of vorticity were compared with the relevant experimental results. The instantaneous spatial-temporal distribution of the particles are given and analyzed. The effects of the coherent structure on the diffusion and distribution of particle number concentration, polydispersity are discussed in detail.