Determination Of Size Distribution Research Articles

Notoginsenoside as an environmentally friendly shale inhibitor in water-based drilling fluid

The demand for non-toxic and biodegradable shale inhibitors is growing in the drilling industry. In this paper, the effect of notoginsenoside (NS) as a new, environmentally friendly inhibitor of shale hydration is systematically studied for the first time. The inhibition performance of NS was evaluated via inhibition evaluation tests, including mud ball immersion tests, linear expansion tests, shale rolling recovery tests, and compressive strength tests. The inhibition mechanism of NS was analyzed using Fourier transform infrared spectroscopy (FTIR), contact angle measurements, particle size distribution determination, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The experimental results demonstrate that NS is able to adhere to the clay surface, forming a hydrophobic film that prevents the entry of water molecules and inhibiting the hydration dispersion of the clay. Because of this, NS can maintain the original state of bentonite pellets in water, which can effectively reduce the swelling rate of bentonite, increase the recovery rate of shale drill cuttings, maintain the strength of the shale, and therefore maintain the stability of the borehole wall during drilling. In addition, NS is non-toxic, degradable, and compatible with water-based drilling fluids. The above advantages make NS a promising candidate for use as an environmentally friendly shale inhibitor.

Drop Size Distribution and Effective Determination of the Constitution of Throughfall Droplets under Maize Canopy

AbstractSprinkler irrigation has dominated the irrigation erosion, and droplet diameter is an important determinant. To clarify the influence of maize canopy and sprinkler droplets landing angle on drop size distribution, distribution trend, and throughfall droplets diameters, the information on droplet size and velocity are collected via 2D‐video‐disdrometer. The results showed that due to the presence of maize canopy and the decrease in landing angle, the proportion of the tiny droplets (<2 mm) within throughfall increased. Throughfall droplet size distribution under maize canopy exhibited a distinct bimodal trend, however, the new droplet volume ratio is greater when the droplet size is smaller. In addition, the trend‐line of throughfall droplet size distribution gradually shifted toward the origin as the landing angle decreased. Because of maize canopy and gradual decrease in the landing angle, throughfall droplets diameters decreased. When the droplets are <2 mm, their volume proportion is greater than that in the absence of maize canopy because of the fragmentation of large droplets. Affected by the convergence of small droplets on maize leaves, the diameter of drips generated from maize leaves in this study probably ranged from 2–5 mm. Drops >5.01 mm maight have originated from direct throughfall.

Numerical determination of bubble size distribution in Newtonian and non-Newtonian fluid flows based on the complete turbulence spectrum

Gas-liquid mass transfer in non-Newtonian fluids is a crucial aspect of the bioprocess industry. Mass transfer is analyzed using the coefficient kLa, which is limited by the rheology since it exerts a barrier to the fluid deformation, significantly affecting the oxygen diffusivity and the bubble breakup and coalescence. However, the traditional mathematical expressions to model the bubble size distribution from bubble breakup and coalescence in turbulent flows of Newtonian fluids are restricted to the inertial sub-range of turbulence where the kinetic energy is dominated only by the microscales. Application of the Newtonian models to non-Newtonian fluids could result in inaccurate predictions by not considering the continuous phase rheology. The main goal of this research is the numerical determination and experimental comparison of bubble sizes in different axial positions of a bioreactor stirred by a Rushton turbine. Emphasis was placed on the viscosity effects on simulating bubble dispersion in a Newtonian fluid (water) and its comparison with a non-Newtonian fluid (0.4 % CMC). The mathematical framework is constructed by coupling the hydrodynamics (through computational fluid dynamics CFD) and bubble breakup and coalescence from a turbulence perspective using the complete energy spectrum that considers the contributions from the energy containing, inertial, and dissipation sub-ranges. This is achieved by including the second-order structure–function. The results of bubble sizes and kLa were compared with experimental data, and acceptable agreement was achieved. Therefore, it is shown that the viscous effects were captured numerically by the entire energy spectrum and improved the predictions of the kLa and bubble sizes compared to the traditional structure function turbulence models.

Prospects and Challenges for the Spatial Quantification of the Diffusion of Fluids Containing 1H in the Pore System of Rock Cores

AbstractNuclear magnetic resonance (MR) (NMR) is commonly used for the determination of rock porosity, as well as pore size distribution (PSD) and tortuosity, required to handle hydrocarbon exploitation. Emerging technologies for NMR equipment now enable the visualization of porosity using magnetic resonance imaging (MRI). Currently, single‐point imaging is the most common MRI technique employed, but diffusion‐weighted imaging has been attracting the attention of geologists and geophysicists. In this study, a more advanced technique, diffusion tensor imaging (DTI), is proposed for the characterization of rock core samples. The main purpose of this paper is to demonstrate the usefulness of DTI in the petrophysical characterization of rocks and discuss its strengths. As an example, a carbonate core sample was examined using DTI. The diffusion tensor (DT) was obtained and DT parameters (mean diffusivity, MD; fractional anisotropy, FA; three eigenvalues; DT components; and proton density, PD) were visualized in 2D and 3D. Each parameter was described and its utility in terms of pore space characterization was analyzed. In addition, a new parameter, principal diffusion tracts, was introduced based on the DT tractography performed in the study. The analysis is summarized in a set of DT parameters and a resultant ellipsoid that delivers complementary information about the sample's pore network microgeometry, including referential measurements of anisotropic phantoms. The applications of DTI for the determination of pore size distribution, tortuosity and conductivity are also shown. The study ends with a consideration of the potential prospects and challenges for DTI‐based examination of rock core samples.

Retrieval of Size Distribution and Concentration of Au-Ag Alloy Nanospheroids by Spectral Extinction Method.

In order to monitor the synthesis processes or characterize nanoparticles for application, a new method that allows in situ determination of the two-dimensional size distribution and concentration of Au-Ag alloy nanospheroids, based on their extinction spectrum, is developed. Non-negative Tikhonov regularization and T-matrix method were used to solve the inverse problem. The effects of the two-dimensional size steps, wavelength range, and measurement errors of extinction spectrum on the retrieval results were analyzed to verify the feasibility and accuracy of the retrieval algorithm. Through comparative analysis, the size steps and wavelength range that make the retrieval error smaller are found. After adding 0.1% random noise to the extinction spectrum, a small variation in the retrieval error of the mean size is observed. The results showed that the error of the mean size is smaller than 2% and the error of the concentration is smaller than 3%. This method is simple, fast, cheap, nondestructive, and can be done in situ during the growth process of nanoparticles.

Determination of pore size distribution in tight gas sandstones based on Bayesian regularization neural network with MICP, NMR and petrophysical logs

Mercury injection capillary pressure (MICP) is one of the most important means for quantitative study of pore structure, however, its application is often limited due to its expensive, destructive and dangerous characteristics. Nuclear magnetic resonance (NMR) then becomes a common alternative by log-linear conversion of transverse relaxation time (T2) spectrum into pseudo-MICP or pore size distribution (PSD) though the accuracy and generality is unconvincing. Petrophysical logs have rich geological-petrophysical information but are seldom used in pore structure research. In this paper, PSD determination of tight gas sandstones based on Bayesian regularization neural network (BRNN) with MICP, NMR and petrophysical logs is studied. A numerical workflow is developed to preprocess MICP and NMR experimental data and determine PSD. Subsequently, two BRNN models are constructed respectively with joint laboratory T2 spectrum and petrophysical logs as main inputs and pore radius and mercury saturation from MICP measurement as training target. It is revealed that, accurate PSD can be determined from prediction results of BRNN models, wherein the NMR-based BRNN can be employed to obtain PSD from more easily accessible NMR measurement and the log-based one is expected to be generalized in the field. Conversion of PSD by fitting pore radius with T2 through their piecewise linear or quintic polynomial relation in log-log coordinate is equivalent to underfitting or overfitting in accuracy of machine learning and is confined to laboratory NMR with joint MICP. Detailed discussion on BRNN modeling, pore radius fitting and the corresponding numerical workflow proposed here may provide valuable insight into petrophysical-log analysis and quantitative evaluation on pore structure of complex reservoirs.

Effect of Organic Matter Removal by Hydrogen Peroxide on the Determination of Soil Particle Size Distribution Using the Dynamometer Method

The dynamometer method of determining particle size distribution was developed several years ago. The principles of sample preparation for this method are based on those used in other sedimentation methods. With improvements in these procedures, an investigation of the effect on obtained particle size distribution results by removing organic matter using hydrogen peroxide was proposed. For this purpose, the particle size distributions were determined in 50 soil samples with varying organic matter content, before and after organic matter removal. A comparative analysis of the results, including calculation of the Euclidean distance, was performed on both groups. It was found that differences in the particle size distributions of the soils after the application of hydrogen peroxide were difficult to predict, and irregular in both magnitude and direction. However, in light soils, the process of organic matter removal caused an increase in the clay fraction at the expense of the silt fraction, which decreased. In soils with a higher initial clay fraction, there were decreases in the clay and sand fractions, while the silt fraction increased.

Towards a generic protocol for measuring the constituent particle size distribution of E171 in food by electron microscopy

Food additive E171 (titanium dioxide, TiO 2 ) is authorized to be used as food colorant in the European Union. E171 is a particulate material, containing a fraction of nanoparticles. A major challenge for food control laboratories is the lack of harmonized, validated analytical methods for measuring the physicochemical properties of nanoparticles in food. This study proposes a generic method for the determination of the number-based size distribution of the constituent particles of E171 in food products based on transmission electron microscopy (TEM). As proof of concept, the protocol was evaluated on 20 food products containing E171 and one personal care product containing titanium dioxide. The total titanium concentration in the products measured by inductively coupled plasma - mass spectrometry (ICP-MS) ranged from 0.1 to 4.0 g/kg, corresponding to 0.2–6.7 g TiO 2 /kg. The required initial mass of starting product needed for TEM analysis was estimated from the ICP-MS concentration. Sample preparation included matrix digestion, a first centrifugation step to remove the remaining food matrix, sonication to reduce agglomeration, and a second centrifugation step to concentrate the sample. Descriptive TEM analysis showed that five food products, labelled to contain E171, contained smaller rutile TiO 2 particles (20–40 nm) coated with mica, which are potassium aluminium silicate-based pearlescent pigments. For 14 other food products and the personal care product, the protocol resulted in a homogenous distribution of the TiO 2 particles over the grid surface. In general, variation between products in the number of particles on the grids was limited; on average, 672 ± 173 particles were measured in 10 images. The median of the minimum Feret diameter distribution varied from 72 ± 7 nm to 135 ± 14 nm. The percentage of nanoparticles (minimum Feret diameter smaller than 100 nm) ranged from 23% to 82%. The corresponding mass percentages of these fractions ranged from 3% to 41%. The percentages of E171 particles smaller than 30 nm was very low (3% or less) while corresponding mass fractions were negligible. For only one food product, the TiO 2 concentration was too low to apply the protocol without adaptations. • A generic protocol for particle size measurement of E 171 in food is proposed. • The protocol is designed for transmission electron microscopy. • The protocol was evaluated on 20 food products and one personal care product. • The median Fmin varied from 72 ± 7 nm to 135 ± 14 nm. • The percentage of nanoparticles (<100 nm) ranged from 23% to 82%.

Determination of Particle Size Distribution and Electrokinetic Potential of Phyllosilicate Powders by Photon Correlation Spectroscopy

Determination of Particle Size Distribution and Electrokinetic Potential of Phyllosilicate Powders by Photon Correlation Spectroscopy

Development and validation of New analytical method for the determination of particle size distribution of tadalafil drug substance using laser particle analyzer

Development and validation of New analytical method for the determination of particle size distribution of tadalafil drug substance using laser particle analyzer

Influence of Hydrodynamic Conditions on Precipitation Kinetics of Barium Sulfate in a Multifunctional Reactor

In this paper, the influence of hydrodynamic conditions in Kenics static mixer, which acts as a multifunctional reactor, on precipitation kinetics of barium sulfate is investigated. The investigated range of the Reynolds number varied between 500 and 5000, which covered both laminar and turbulent flow regimes. In all experiments, the relative supersaturation was maintained at the constant level (σ = 205). The obtained precipitate was collected and used for crystal size distribution (CSD) determination. On that basis, the kinetic parameters of the process were calculated using the mixed suspension mixed product removal (MSMPR) mathematical model of the process. It was found that for the whole investigated range of Reynolds number, the mixing conditions were satisfactory. CSD analysis showed that in the laminar regime, a clear tendency in crystal behavior could not be noticed. However, during the analysis of the turbulent regime, the presence of a critical Reynolds number was noticed. Above this value, there is a change in the flow pattern, which results in a change of kinetic parameters (B, G), as well as manifests in a form of a decrease in the value of mean diameters of crystals. The flow pattern change is caused by the geometry of the reactor’s inserts.

Hranjiva i energetska vrijednost kukuruzne silaže na mliječnim farmama Istočne Hrvatske

The aim of this study was to determine the quality of corn silage as the dominant component in the diet of dairy cows in three counties of Eastern Croatia; Brod-Posavina, Osijek-Baranja, and Vukovar-Srijem. The practical part of the research included 25 dairy farms in each County in which corn silage was sampled and then analyzed. The monitored nutritional, fermentative, and physical indicators expressed as average values were satisfactory. Indicators of chemical composition: dry matter (DM) = 349 g/kg, crude protein = 71 g/kg DM, crude ash = 39 g/kg DM, crude fiber = 186 g/kg DM, acidic detergent fiber (ADF) = 212 g/kg DM, neutral detergent fiber (NDF) = 393 g/kg DM, acidic detergent lignin (ADL) = 17 g/kg DM, starch = 325 g kg DM, energy value expressed in net energy for lactation (NEL, MJ/kg DM) = 6.78, average digestibility of organic matter (dOM) = 75.8% and digestible neutral detergent fibers (dNDF)= 53.7%. Indicators of silage fermentation included the measurement of an average pH of 3.86, a concentration of lactic acid = 56.37 g/kg DM, and acetic acid of 20.68 g/kg DM. Physical indicator, determination of silage particle size distribution (three sieve system) recorded following values: sieve 1 = 7.1%; sieve 2 = 56.3%; sieve 3 = 24.8% and box at the bottom = 11.7%. Given the established statistical significance of the tested differences in average values for nine indicators of nutritional and energy value of corn silage between counties, it is possible to confirm that the quality of silage was better in Osijek-Baranja and Brod-Posavina counties than in Vukovar-Srijem County. Based on significant deviations in the minimum and maximum, and by determining a larger number of non-compliant samples in some indicators than the average values, it leads to the conclusion of uneven quality of silage in some producers.

Determination of particle size distribution by polarization analysis of the scattered light

Fast online acquisition of particle size distribution has become a significant technique for both laboratory research and industrial application. In this paper, a particle sizing method based on the analysis of scatted light through image processing is proposed. Polarization ratio, which is defined by the ratio of the scattered intensity component polarized perpendicular to that polarized parallel, is induced to quantify the polarization status which, according to Mie scattering theory, is dependent on the particle diameter under a certain operating condition when the refractive index of the particle is known. Test rig is set up to realize the simultaneous acquisition of particle images polarized both perpendicular and parallel on CCD camera. Through image processing, the polarization ratio of the scattered light is obtained, based on which inverse calculation is performed according to Mie theory. The presented method is then applied to the size distribution determination of polystyrene particles suspending in water. The results obtained from experiments are compared with the calibrated values which renders a deviation less than 10%. The optical setup is also applied to the sizing of water droplets generated by an atomizer, which provides reasonable size distributions under different operating conditions in line with the reference values provided by the fabricator.

Determination of deferasirox particle size distribution via laser diffraction and its application in establishing a correlation between particle size and drug dissolution in vitro

Determination of deferasirox particle size distribution via laser diffraction and its application in establishing a correlation between particle size and drug dissolution in vitro

In Situ Determination of Droplet and Nanoparticle Size Distributions in Spray Flame Synthesis by Wide-Angle Light Scattering (WALS).

The investigation of droplet and nanoparticle formation in spray flame synthesis requires sophisticated measurement techniques, as often both are present simultaneously. Here, wide-angle light scattering (WALS) was applied to determine droplet and nanoparticle size distributions in spray flames from a standardized liquid-fed burner setup. Solvents of pure ethanol and a mixture of ethanol and titanium isopropoxide, incepting nanoparticle synthesis, were investigated. A novel method for the evaluation of scattering data from droplets between 2 µm and 50 µm was successfully implemented. Applying this, we could reveal the development of a bimodal droplet size distribution for the solvent/precursor system, probably induced by droplet micro-explosions. To determine nanoparticle size distributions, an appropriate filter and the averaging of single-shot data were applied to ensure scattering from a significant amount of nanoparticles homogeneously distributed in the measurement volume. From the multivariate analysis of the scattering data, the presence of spherical particles and fractal aggregates was derived, which was confirmed by analysis of transmission electron microscopy images. Monte Carlo simulations allowed determining the distribution parameters for both morphological fractions in three heights above the burner. The results showed relatively wide size distributions, especially for the spherical fraction, and indicated an ongoing sintering, from fractal to spherical particles.

Synthesis of nanomaterials by electrode erosion using discharges in liquids

Discharges in liquids are very efficient to synthesize nanoparticles by electrode erosion. This simple process is only simple in appearance. Mechanisms responsible for the production of nanoparticles are several depending on the choice of process parameters. They determine size distributions, shapes, composition, and defects of produced particles. They also control their possible assembly into more complex structures. This article describes the basic physics of nanoparticles’ synthesis by discharges in liquids using electrodes and gives a summary of the research efforts that have been devoted to the understanding of this process. A special attention is paid to thermodynamics of these systems driven by discharges that are at or close to local equilibrium. Although a complete picture is not available yet, huge progress has been made and offers new capabilities for a better control of these kinds of processes. Finally, among important challenges that are still to tackle, the possibility of forming nanoalloys from immiscible elements or achieving unimodal monodisperse size distributions is questioned from the current mastery reached in this field.

An original methodology to study polymeric nanoparticle-macrophage interactions: Nanoparticle tracking analysis in cell culture media and quantification of the internalized objects

Poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) are among the most employed (co)polymers for the preparation of drug nanocarriers for the treatment of cancer and infectious diseases. Before considering any clinical use, it is necessary to understand the interactions between polymeric nanoparticles (NPs) and their physiological environment, especially immune cells. Here, we propose a simple, yet precise method to assess NPs internalization kinetics in macrophages, based on the direct analysis of the cell culture media after different incubation times. The proof of concept is given here by using fluorescent PLGA NPs. Nanoparticle tracking analysis (NTA) was a method of choice, enabling detecting each individual NP and analyzing its trajectory while in Brownian motion. As compared to dynamic light scattering (DLS), NTA enabled a more precise determination of NP size distribution. The uptake process was rapid: in one hour, around a third of the NPs were internalized. In addition, the internalized NPs were visualized by confocal microscopy. The fluorescent cellular stacks were analyzed using a freely available macro for ImageJ software, Particle_In_Cell-3D. The internalized objects were localized and counted. This methodology could serve for further studies while analyzing the effects of NPs size, shape and surface properties on their interaction with various cell lines.

Comprehensive Analysis of Hierarchical Porous Carbons Using a Dual-Shape 2D-NLDFT Model with an Adjustable Slit-Cylinder Pore Shape Boundary.

A thorough characterization of the textural properties of hierarchical porous carbons (HPCs) is of utmost importance as it provides information that aids in the selection of a suitable material for a given application and in understanding the phenomena observed once the material becomes part of a system. Gas adsorption-desorption isotherms coupled with the application of density functional theory (DFT) models to these isotherms are common tools for the textural characterization of HPCs, for which pore shape is an essential factor for the determination of pore size distributions (PSDs). By analyzing the experimental adsorption data of a series of CO2-activated HPCs with a progressive development of porosity, it is shown that artifacts are found in the derived PSDs when a slit-cylinder pore shape boundary is fixed at 2 nm, which is the case for the original dual-shape nonlocal DFT (2D-NLDFT-HS) and hybrid quenched solid DFT (QSDFT) models. This study presents a new dual-shape 2D-NLDFT-HS (DS-HS) model that, combined with the 2D-NLDFT-HS model for CO2, provides the possibility of analyzing simultaneously N2 and CO2 adsorption-desorption isotherms and adjusting at the same time the limits for the assumed slit and cylindrical pore shapes. Using the DS-HS approach and adjusting the slit-cylinder boundary at 3 nm allowed eliminating PSDs artifacts. The interactive adjustment of the slit-cylindrical pore shape boundary of the DS-HS model represents a major advantage of this approach allowing for a comprehensive analysis of the adsorption data and a more accurate description of the textural properties of HPC materials.

Image Analysis Algorithm-Based Platform for Determining Micron and Higher Aggregate Size Distribution of Therapeutic IgG Using Brightfield and Fluorescence Microscope Images.

A platform for determining size distribution of micron (1-100μm) and larger (> 100μm) aggregates of therapeutic IgG has been established by using image processing algorithms for brightfield and fluorescence microscope images. The algorithm for brightfield images involved conversion to grayscale followed by pixel-based and size-based thresholding. Morphological operations were then applied and the size distribution of aggregates were extracted. Fluorescence images of the aggregates of mAb tagged by a fluorescent dye were captured using widefield fluorescence microscope, confocal laser scanning microscope, and Cytell Cell Imaging System and the images were processed using a series of denoising steps followed by thresholding and morphological operations. The samples were subjected to different stresses, among which the aggregates were visible in the microscope for sample subjected to bubbling, stirring, and temperature. The images of these aggregates were effectively denoised and the size distribution of aggregates was analyzed using the algorithm. The overall aggregate size distribution obtained by image processing ranged in the micron and higher size range. The size obtained from brightfield image processing was validated using images of liquid chromatography resins. Further, the aggregate size distribution obtained using image processing was compared with experimental techniques such as Mastersizer 2000 and Micro Flow Imaging. It was found that analysis of IgG aggregates using image processing could serve as an orthogonal methodology to the existing approaches.

Thermal Conductivity of Sand-Lime Products Modified with Foam Glass Granulate.

Waste glass constitutes a significant part of general waste worldwide. Unfortunately, only a small percentage is recycled. It is, therefore, quite important that it can be applied in the production of construction materials. The main aim of this article is to determine the thermal conductivity of the products modified with granulated foam glass (GFG) (recycled product) of the 0.25–0.5 mm fraction, as well as to indicate dependence of the change in volume density of samples caused by the use of GFG and the change of the thermal conductivity coefficient compared to reference samples. For the purpose of this research, various parameters were examined i.a. volume density, water absorption, determination of the pore size distribution by mercury porosimetry and determination of the heat conduction coefficient with the use of a plate apparatus. The test results were developed on the basis of a mathematical model that determined the influence of the filler on the functional properties of the product. The research has shown that the use of GFG in the sand-lime products will contribute to lowering their thermal conductivity by more than 50% compared to traditional products.