Particle Size Distribution Analysis Research Articles

The effects of ultrasonic wave on heterogeneous coagulation and flotation separation of pentlandite-serpentine

It is well known that in the flotation of copper-nickel sulfide ore, pentlandite and serpentine are easy to form hetero-aggregation, which makes it difficult to separate them. Therefore, dispersion operation is indispensable, including chemical and physical dispersion. Chemical dispersion is usually achieved by adding dispersing reagents, which is widely used in mineral flotation, while the study of ultrasonic dispersion in copper-nickel sulfide ores in physical dispersion is less reported. Thus ultrasonic dispersion technology was introduced to weaken the hetero-aggregation and to improve the floatability of pentlandite. Through the implementation of a series of conditional tests of influence factors including ultrasonic site, ultrasonic probe type, ultrasonic time, and ultrasonic power, the optimum ultrasonic dispersion system was demined, and the results showed that the ultrasonic power was the key factor affecting the dispersion of pentlandite-serpentine. Then the dispersion mechanism of ultrasonic was revealed by means of supernatant turbidity measurements, particle-size distribution (PSD) analyses, scanning electron microscopy (SEM), and atomic force microscope (AFM) in succession. Coupled with supernatant turbidity measurements, PSD analyses and SEM images of flotation concentrates all confirmed that the ultra-fine serpentine particles coating on the coarse pentlandite particles were effectively dispersed. AFM analyses depicted the morphological changes of surface roughness treated by different ultrasonic power, and confirmed that the ultrasonic power of 200 W could increase the surface roughness and floatability of pentlandite but decrease that of serpentine. Thus, the difference in floatability between the two minerals were enlarged so as to achieve efficient separation of the two minerals. The results of this research are helpful to understand clearly the mechanism of ultrasonic dispersion of pentlandite-serpentine, which provides an alternative dispersion technology and exhibits great potential for further study and application.

Effects of Particle Size Distribution and Impact Speed on Printing Quality in Direct Energy Deposition

Particle Size Distribution (PSD) has been studied as an important factor that will affect printing quality in selective laser sintering/melting (SLS/SLM). However, few studies investigated the effects of particle size distribution and associated impact speeds on the quality of printed surfaces in Direct Energy Deposition (DED) processes. Due to the different characteristics of powder bed and powder fed printing mechanism, particle size distribution could be evaluated before the printing but could not be assessed in-situ during the printing process of SLS/SLM. The powder stream of the DED process provides the opportunity to evaluate the PSD in-situ using a novel laser diffraction method. The laser diffraction method was a well-established particle size distribution analysis method for soil granite. It can achieve a fast, accurate, and in-situ analysis but has never been studied in DED printing. In this study, a novel laser diffraction PSD analyzer was proposed. A high-speed camera was applied to investigate the relationship between the impact speed and carrier gas flux. Stainless steel 316L metal powders with different PSDs and impact speeds were DED printed, the surface roughness and tensile strength were measured to evaluate the effects of impact speeds and PSDs on the printing quality. The results showed that impact speed and PSD had considerable influences on the printed surface roughness and tensile strength of printed parts. This study paves the way for adopting laser diffraction as an in-situ monitoring tool for the DED processes.

Mechanochemical Synthesis of Nickel Mono- and Diselenide: Characterization and Electrical and Optical Properties.

Nickel mono- (NiSe) and diselenide (NiSe2) were produced from stoichiometric mixtures of powdered Ni and Se precursors by the one-step, undemanding mechanochemical reactions. The process was carried out by high-energy milling for 30 and 120 min in a planetary ball mill. The kinetics of the reactions were documented, and the products were studied in terms of their crystal structure, morphology, electrical, and optical properties. X-ray powder diffraction confirmed that NiSe has hexagonal and NiSe2 cubic crystal structure with an average crystallite size of 10.5 nm for NiSe and 13.3 nm for NiSe2. Their physical properties were characterized by the specific surface area measurements and particle size distribution analysis. Transmission electron microscopy showed that the prepared materials contain nanoparticles of irregular shape, which are agglomerated into clusters of about 1–2 μm in diameter. The first original values of electrical conductivity, resistivity, and sheet resistance of nickel selenides synthesized by milling were measured. The obtained bandgap energy values determined using UV–Vis spectroscopy confirmed their potential use in photovoltaics. Photoluminescence spectroscopy revealed weak luminescence activity of the materials. Such synthesis of nickel selenides can easily be carried out on a large scale by milling in an industrial mill, as was verified earlier for copper selenide synthesis.

Effects of Polymers on the Drug Solubility and Dissolution Enhancement of Poorly Water-Soluble Rivaroxaban.

The purpose of this study was to investigate the efficacy of hydrophilic polymers in a solid dispersion formulation in improving the solubility and dissolution rate of rivaroxaban (RXB), a poorly soluble drug. The developed solid dispersion consisted of two components, a drug and a polymer, and the drug was dispersed as amorphous particles in a polymer matrix using the spray drying method. Polymeric solid dispersions were evaluated using solubility tests, in vitro dissolution tests, powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and particle size distribution analysis. To maximize physical stability against crystallization and improve the solubility and dissolution of RXB, it is important to select the appropriate polymer type and the optimal ratio of the polymer to the drug. The optimized polyvinyl alcohol (PVA)-based (1/0.5, w/w) and gelatin-based (1/5, w/w) solid dispersion formulations showed 6.3 and 3.6 times higher drug solubilities than pure RXB powder, respectively, and the final dissolution rate was improved by approximately 1.5 times. Scanning electron microscopy and particle size distribution analyses confirmed that the gelatin-based solid dispersion was smaller and more spherical than the PVA-based solid dispersion, suggesting that the gelatin-based solid dispersion had a faster initial dissolution rate. Differential scanning calorimetry and powder X-ray diffraction analyses confirmed that RXB had successfully changed from a crystalline form to an amorphous form, contributing to the improvement in its solubility and dissolution rate. This study provides a strategy for selecting suitable polymers for the development of amorphous polymer solid dispersions that can overcome precipitation during dissolution and stabilization of the amorphous state. In addition, the selected polymer solid dispersion improved the drug solubility and dissolution rate of RXB, a poorly soluble drug, and may be used as a promising drug delivery system.

Decontamination of endocrine disruptors from water by graphene nanoplatelet/UiO-66 nanocomposites

Zirconium-based metal–organic frameworks (UiO-66) and graphene nanoplatelets were chosen for preparing nanocomposites (GNP/UiO-66) in this study. The hydrothermal method was used for this purpose. Obtaining composite material was characterized by XRD, FTIR, SEM, BET surface area, and particle size distribution analysis. The size of nanocomposite was nearly 600–750 nm. The surface area was 910.581 m2/g. Adsorption of endocrine disruptors (diclofenac sodium and bisphenol A) from the water was performed by GNP/UiO-66. According to the amount of adsorbent experiments; BPA was adsorbed at 48.33 mg/g and the maximum adsorption efficiency of BPA is 28.53 %. The maximum DCF adsorption uptake was 120.95 mg/g at 0.0025 g, and adsorption efficiency was 99.02 % at 0.01 g. Both of the adsorbates followed PSO kinetic model and calculated qe values were 452.46 mg/g for DCF and 53.91 mg/g for BPA. According to Temkin and Freundlich isotherms, it is understood that temperature increasing causes decreasing of adsorption efficiencies of DCF and BPA. The Dubinin-Radushkevich isotherm parameters explained that DCF adsorption followed chemical adsorption mechanism and BPA adsorption followed physical adsorption mechanism.

Recent Advances in Deep Eutectic Solvents as Shale Swelling Inhibitors: A Comprehensive Review.

Inhibitors have evolved from their primary function of controlling swelling during hydraulic fracturing processes in shale reservoirs. This study provides a comprehensive review of recent deep eutectic solvent (DES) advancements as inhibitors in swelling inhibition techniques. The swelling inhibitory potentials and mechanisms of DESs have been studied analytically and compared to existing conventional inhibitors. The functional effects of concentration, temperature, and types of DES are explored. Data on the effect of DES on rheology, swelling, zeta potential, shale cutting recovery, surface tension, particle size distribution, XRD, and FTIR analyses are presented. Along with preparation procedures, environmental concerns and applications of DESs in several fields are discussed. This study suggests that DESs are preferable swelling inhibitors due to their inhibitory performance, cost-effectiveness, and environmental friendliness. Moreover, this review includes guidelines and recommendations for selecting and designing DES to inhibit swelling more effectively.

Ethylene glycol based polyurethane shell microcapsules for textile applications releasing medicinal lavender and responding to mechanical stimuli

Interfacial polymerization has been used to encapsulate essential oils (EOs). Nevertheless, interfacial polymerization to form polymeric interface of EOs with the environment has been poorly studied. The objective of this study was to develop a kind of polyurethane (PU) based shell microencapsulated EOs to induce controlled delivery. In this study, ethylene glycol based PU microcapsules were prepared to release medicinal lavender oil from some textiles with controlled delivery mechanism and mechanical stimuli. Various diisocyanates and ethylene glycol (EG) are used to synthesize the PU based shell microcapsules for optimization and reveal structure property relationship of shell structure in controlled release issue. The sensing mechanical stimuli of the polymer capsules is achieved by using a short molecule, EG. The original lavender fragrance was encapsulated in PU shells by the interfacial interaction of toluene diisocyanate, isophorone diisocyanate, or methylene bisphenol diisocyanate with EG at the interface of oil and water phases. The fragrance capsules were characterized by Fourier Transform Infrared (FT-IR) spectroscopy, particle size distribution (PSD) analysis, polarized optical microscopy (POM) and scanning electron microscopy (SEM) investigations. The release behavior of the fragrance capsules was determined by periodic weight checks over 30 days. According to the release analysis, the efficient EOs encapsulation ratio of the particles were 34.90%, 39.84% and 48.70% for particles produced using toluene diisocyanate, isophorone diisocyanate, and methylene bisphenol diisocyanate respectively. The average particle size was determined in a range of 10–30 µm for the particles produced used any diisocyanate, which meant they were at commonly used sizes for textile applications. The -NH, -CO, -C-O-C, and -C-N peaks in the structure of the PU were determined by FT-IR to demonstrate successful synthesis. SEM images revealed that microparticles with medicinal lavender oil were fragile to increase the release rate when needed.

Analysis of particle size distribution in municipal wastewaters

Innovative membrane filtration plants for municipal wastewaters are being developed and need the support of reliable filtration models in the designing phase. In the past, semi-empirical filtration models for membrane processes have been proposed. At present, the most prominent works point out the importance of particle poly-dispersity in the development of reliable models but fail into the implementation of probability density functions (PDFs) capable of an accurate fitting of the experimental particle size distribution (PSD). We report the experimental PSDs of two different municipal wastewater samples, obtained through the laser diffraction technique. The experimental results show that the laser diffraction technique can characterize wastewater particle dimensions both in the colloidal and supra-colloidal regions. The experimental study is complemented by a comparative analysis in which many PDFs are used to fit the experimental PSDs through a least-squares approach. Some of these PDFs are proposed here for the first time to fit experimental wastewater PSDs. Among the PDFs considered for the statistical modeling, the three-parameter lognormal and the Burr PDFs are demonstrated to provide satisfactory fitting, whereas the other considered functions fail. This result is confirmed by the analysis of both the available wastewater samples. • Experimental data of particle size distribution in municipal wastewaters. • Experimental data from laser diffraction technique. • Fitting of probability density functions to experimental data through a least-squares approach. • Several probability density functions tested. • Burr and three-parameter lognormal densities capture well the experimental data.

Assessing the effect of multiple variables on the production of bioflocculant by Serratia marcescens: Flocculating activity, kinetics, toxicity, and flocculation mechanism.

Bioflocculants gain attention as alternatives to chemical flocculants because they are more environmentally friendly and highly biodegradable. This study aims to improve the bioflocculant production by Serratia marcescens using one-variable-at-a-time (OVAT) analysis and analyze its flocculating activity performance, toxicity, and the flocculation mechanism. The effect of multiple variables including initial inoculum size, pH, mixing speed, temperature, growth medium, and incubation period was assessed through OVAT. Flocculating activity was then determined via jar test analysis, and toxicity test was performed using Daphnia magna and Daphnia pulex. The flocculation mechanism was determined via particle size distribution and zeta potential analysis. The optimum conditions for the improved bioflocculant production were as follows: 10% v/v initial inoculum size, pH 7, mixing speed of 150 rpm, room temperature, nutrient broth medium, and 72 h of incubation period. Scanning electron microscopy showed flake-like intact structure with coarse surface. The produced bioflocculant showed flocculating activity of 48% in 5227 ± 580 NTU initial kaolin turbidity with 1 mg/L concentration and 5% v/v dosage of bioflocculant, following the second-order kinetics. Toxicity test to D. magna and D. pulex showed the 48 h LC50 values of 8.06 and 6.42 g/L, respectively; these values are greatly higher than the fabricated chemical flocculants. The flocculation process using bioflocculant produced by S. marcescens was suggested to occur via bridging mechanism because it greatly affected the particle size distribution. Results indicated that bioflocculant produced by S. marcescens is much environmentally friendly and has great potential for turbidity removal in water/wastewater.

Preparation of Polyurethane/Acrylate Composite Emulsion for Inkjet Printing

Water-borne polyurethane/acrylate (WPUA) emulsion was prepared through emulsion polymerization between vinyl terminated waterborne polyurethane (WPU) and methyl methacrylate (MMA) in this research. Thermogravimetric Analysis (TGA), transmission electron microscopy (TEM), contact angle analysis, and particle size distribution analysis were employed to investigate the performance of the prepared emulsion and coatings with various content of MMA content. The results demonstrated that the thermal resistance, water resistance, and hardness of the prepared WPUA coatings were enhanced by the introduction of the MMA monomer. The contact angle (CA) and particle size of WPUA emulsion increased with the increase of MMA content. Meanwhile, the water-borne inkjet printing ink was prepared using WPUA emulsion as binder resin, and the printing test result showed that the prepared inkjet ink has good printability and color rendering, indicating that WPUA emulsion has great application prospects in the field of inkjet printing.

Effect of Grit Size on Airborne Particle Concentration and Size Distribution during Oak Wood Sanding

Adverse health effects caused by exposure to airborne particles have been detected in recent years, however there is little knowledge about exposure to ultrafine particles with a diameter <100 nm. In this study, particle number concentration and size distribution in a range of particle diameters from 10 nm to 10 µm were determined during oak wood sanding. A hand-held orbit sander in combination with three types of grit size (P60, 120 and 240) of sandpaper were used. Measurements were obtained using a portable particle size distribution analyzer and an optical particle size spectrometer, carried out at 15-min intervals for each treatment by static sampling in the breathing zone. We also compared the optical particle size spectrometer to the aerosol monitor in order to evaluate the mass concentration of airborne particles in the range of 1 to 10 µm in diameter. Sanding paper with the finest grit, P240, showed a significantly higher number concentration of ultrafine particles, compared with P60 and P120 grits. The differences among particular grit size were statistically significant for microparticles. The size distribution of particles during sanding was not affected by grit size. For each grit size, apparent peak values of ultrafine and microparticle number concentrations were determined at approximately 15 nm, and 0.1 µm, respectively. Optical particle size spectrometer and aerosol monitor showed comparable results of mass concentration for the respirable fraction.

Atmospheric aerosol particle size distribution from Lidar data based on the lognormal distribution mode

Analysis of the atmospheric Aerosol Particle Size Distribution (APSD) retrieved from Light Detection and Ranging (Lidar) data is one of the popular fields in atmospheric remote sensing. An APSD retrieval method based on the lognormal particle size distribution, the Mie theory, and the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) were studied. According to the 6S, this method divides the main body of the aerosols into four basic components and calculates the APSD from Lidar data and the optical and microphysical characteristics of these components. Numerical simulation and experimental observations reveal that this method can obtain the APSD for particle sizes of >0.15 μm in the different vertical layers with good reliability.

Synthesis and Evaluation of Finasteride-Loaded HPMC-Based Nanogels for Transdermal Delivery: A Versatile Nanoscopic Platform.

Herein, we report nanogels comprising diverse feed ratio of polymer hydroxypropyl methylcellulose (HPMC), monomer acrylic acid (AA), and cross-linker methylene bisacrylamide (MBA) fabricated for transdermal delivery of finasteride (FIN). Free radical solution polymerization method with subsequent condensation was employed for the synthesis using ammonium per sulfate (APS) and sodium hydrogen sulfite (SHS) as initiators. Carbopol-940 gel (CG) was formulated as assisting platform to deliver FIN nanogels transdermally. Developed formulations were evaluated by several in vitro, ex vivo, and in vivo parameters such as particle size and charge distribution analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffractogram (XRD), rheological testing, in vitro swelling and drug release, and ex vivo skin permeation, irritation, and toxicity assessment. The results endorsed the nanogel formation (117.3 ± 29.113 nm), and the impact of synthesizing method was signified by high yield of nanogels (≈91%). Efficient response for in vitro swelling and FIN release was revealed at pH 5.5 and 7.4. Skin irritation and toxicity assessment ensured the biocompatibility of prepared nanocomposites. On the basis of the results obtained, it can be concluded that the developed nanogels were stable with excellent drug permeation profile across skin.

Flotation de-inking for recycling paper: contrasting the effects of three mineral oil-free offset printing inks on its efficiency.

Paper for recycling has become a promising raw material for the pulp and paper industry due to its low cost and because it is conducive to sustainable development. Unfortunately, recycled paper contains a high volume of printed paper that is difficult to deink, which restricts its applications. Flotation deinking plays an essential role in the product quality and process cost of wastepaper recycling. This study was performed to evaluate the deinkability of environmentally friendly offset inks by flotation deinking. For this purpose, three mineral oil free series of four-color inks, namely, hybrid light emitting diode ultraviolet (LED-UV), LED-UV, and vegetable oil-based inks, were printed on white lightweight coated papers under laboratory conditions. The deinking methodology involves repulping, deinking agent treatment, flotation, hand sheet making, and evaluation of the produced hand sheets. The obtained results indicated that the hybrid LED-UV prints had the best deinkability. After flotation deinking, the deinking efficiency and the whiteness of the hybrid LED-UV ink increased by 58.1% and 47.6%, respectively. LED-UV ink had a 46.9% increase in the deinking efficiency and a 37.0% increase in the whiteness of the hand sheet. The deinking efficiency of the vegetable oil-based ink was the lowest, at 42.1%, and the whiteness of the hand sheet increased only by 23.8%. The particle size distribution analysis demonstrated that the hybrid LED-UV four-color ink exhibited a larger value of the average particle size than the two other. Scanning electron microscopy revealed that the hybrid LED-UV ink particles on the surface of the fibers were the least abundant after deinking. The physical strength properties of the hand sheets, including tensile index, folding resistance, and interlayer bonding strength of the hybrid LED-UV, LED-UV inks, and vegetable oil-based inks, increased.

Measurements of suspended ashes concentration in turbulent flow with acoustic doppler velocimeter

Measuring and estimating dispersion coefficients for ash particles released in watercourses is required for a broad understanding of their transport and behaviour in aquatic ecosystems. Calibration of a high-frequency acoustic backscattering system and estimates of its sensitivity to particulates of known size distribution and concentration are presented. Laboratory experiments were conducted to derive the relationship between suspended sediment concentration (SSC) of biomass ashes and the signal-to-noise ratio (SNR) measured by a 10 MHz ADV. Small portions of ashes were added in steps (0.006–20 gl−1) into a stirred water tank while ADV was recording changes in SNR, with various combinations of ADV settings, which included power (LOW, LOW+), transmit length (TL = 0.3 mm, 0.6 mm) and frequencies of data acquisition (25 Hz, 100 Hz). Samples were collected for gravimetric and particle size distribution (PSD) analysis. As expected, the salinity and pH of the collected samples increased with SSC. Different backscatter responses were detected depending on the ADV settings and SSC. To maximize the calibration range, the ADV settings power LOW+, TL = 0.3 mm and sample frequency 25 Hz were combined, resulting in a calibrated SSC range of 10–500 mgl−1, where a linear relationship was obtained. The results suggest that it may be possible to apply a single-frequency acoustic technique to the detection of suspended ashes. The particle type and size distribution changed with a concentration above 0.5 gl−1, which may lead to errors in the acoustic estimates of SSC in ash-laden flows.

Characterisation of Novel Nitrogen Doped Reduced Graphene Oxide

The utilisation of fuel cells in everyday life is of critical importance for the introduction of clean energy and departure from carbon-based economy. The oxygen reduction reaction (ORR) rate on the cathode is the key factor for effective polymer electrolyte membrane fuel cells. Therefore, novel cathode catalysts have to be designed to reduce the ORR over voltage. One of the most efficient ways to increase the ORR rate is to use nitrogen doping of carbon materials.1 Such materials are also promising for applications in supercapacitors and other energy storage devices.2 In this work, experimental results based on a nitrogen-doped reduced graphene oxide are presented. The nitrogen-doped reduced graphene oxide has been produced by Sea Further SARL using a biological micro-organisms and non-toxic chemicals.3 The material has been characterised by several physical methods: particle size distribution analysis, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, gas adsorption method, and electrical conductivity measurements. X-ray diffraction data reveal the presence of peaks characteristic to reduced graphene oxide. The specific surface area of the bulk material is around 2.4 m2 g− 1 based on the nitrogen adsorption method. The bulk sample, in powder form, exhibited considerable specific conductance under pressure.Additionally, electrochemical measurements have been conducted in 0.1 M HClO₄ and 0.1 M KOH solutions. The electrochemical stability, capacitive behaviour, and ORR activity of nitrogen-doped reduced graphene oxide have been determined using cyclic voltammetry, rotating disc electrode and electrochemical impedance spectroscopy methods. The material under discussion has a good electrochemical stability within the investigated potential region in both media. The measurement data show that the ORR kinetics in alkaline media is much faster than in acidic media. Surprisingly, this material has a high gravimetric capacitance. Therefore, nitrogen-doped reduced graphene oxide has high potential for energy storage devices and is promising co-catalyst material in fuel cell. Acknowledgements This work was supported by the EU through the European Regional Development Fund under project TK 141 “Advanced materials and high-technology devices for energy recuperation systems” (grant number 2014 2020.4.01.15 0011); and by the Estonian Research Council (grant number PUT PRG 676). References N. Daems, X. Sheng, I.F.J. Vankelecom, and P.P. Pescarmona, J. Mater. Chem. A, 2, 4085 (2014).N.A. Elessawy, J.E. Nady, W. Wazeer, and A.B. Kashyout, Sci. Rep., 9, 1129 (2019).V. Iakimov, International Patent Application No. WO2021/059152, WIPO, April 1st 2021.

Autonomous Image Analysis to Accelerate the Discovery and Integration of Energy Materials

Accelerating the development of electrochemical energy devices (e.g., batteries, fuel cells, electrolysis cells) is pivotal for the transition towards a green and sustainable energy economy. A significant proportion of development efforts in this realm is relying on new functional materials as electrocatalytically active media, ionic media, porous transport media, or multi-functional electrodes. Experimental materials research harnesses a broad spectrum of imaging and visualization methods, based on modern spectroscopy, microscopy, and scattering techniques. These techniques are utilized to quantify structural characteristics of materials and to detect and monitor structural changes during fabrication and normal operating cycles of the device. The extreme diversity and the complexity of materials leave the applications of conventional methods for image processing often empirical and indiscriminate. Recently, deep learning (DL) models based on deep convolutional neural networks (ConvNets) have been transforming the field of computer vision by outperforming the classical algorithms in various problems such as image recognition, reconstruction, synthesis, style transfer, and other tasks. To leverage the advancements in DL-based approaches in materials research, ConvNet models are employed for various analysis tasks like segmentation, object detection, denoising, or super-resolution microscopy. Here, we will present DL-based methodical pipelines to automate the particle size distribution analysis of Pt nanoparticles in catalyst layers [1] and for high-throughput screening of catalyst layer inks [2] in polymer electrolyte fuel cells.

Heat treatment to increase self-bonding property of binderless boards manufactured from rice straw

Rice straw is an abundant agricultural waste globally, but it has not been used effectively. Binderless boards manufactured without synthetic resins are an environment-friendly material, and they are also a possible way to utilize rice straw. However, the presence of wax and silica on the surface of rice straw reduces the bonding ability. The study objective was to manufacture binderless boards from heat-treated rice straws and investigate the effect of heat treatment on the self-bonding properties. Heat treatment was performed on chips or powder from rice straw (≤50 mm, 1 mm) at 200 °C, 1.5 MPa for 0–60 min. Heat-treated rice straw (≤50 mm, 1 mm, 150 µm) was hot-pressed to form binderless boards at 220 °C and 5 MPa for 10 min. The resulting board was 300 × 300 × 5 mm, 0.8 g/cm3. The mechanical and physical properties of the boards were tested according to the JIS A5905-2014 standards. Electron microscopy (SEM), particle-size distribution, and gas chromatography-mass spectrometry (GC-MS) analyses were conducted to examine the effect of heat treatment. The results showed that heat treatment for more than 40 min increased internal bonding because of physical and chemical changes in the rice straw.

Интерпретация результатов гранулометрического анализа почвы в разных школах почвоведения

The article discusses a few of today's applicable soil classifications in terms of their texture: the one by A. Kachinsky (Russians) and other two – by the US Department of Agriculture (USDA) and the World Reference Base for Soil Resources (WRB). The article also presents several discrepancies in the nature of the source of research (primary soil particles), the width of the borders of the key textural classes, and also in the need to take into account possible ways of their formation when classifying. Bearing it in mind, we have studied 57 separate soil samples of the Calcic Chernozem of the Rostov Region. The comparative study of the results of the particle-size distribution analysis was performed based on the results obtained with the help of the laser diffraction method, since it is not directly related to any of the above classifications, thus being free from whatever lasting stereotypes. The choice of options for the conditions of soil formation as presented in the Russian classification seems a key decisive parameter while interpreting experimental results. In the example under consideration, this classification allows for defining the variety of a textural class as clay (from light to heavy) depending on what type of soil formation the sample may be related to. Due to some discrepancies in determining the boundaries of the textural classes, we have observed redistribution of primary soil particles whereas their factual amount remains unchanged. All these differences are vital nowadays in view of globalization and boost in the number and importance of international research.

Carnosic Acid Encapsulated in Albumin Nanoparticles Induces Apoptosis in Breast and Colorectal Cancer Cells.

Carnosic acid (CA) is a natural phenolic compound with several biomedical actions. This work was performed to study the use of CA-loaded polymeric nanoparticles to improve the antitumor activity of breast cancer cells (MCF-7) and colon cancer cells (Caco-2). CA was encapsulated in bovine serum albumin (BSA), chitosan (CH), and cellulose (CL) nanoparticles. The CA-loaded BSA nanoparticles (CA-BSA-NPs) revealed the most promising formula as it showed good loading capacity and the best release rate profile as the drug reached 80% after 10 h. The physicochemical characterization of the CA-BSA-NPs and empty carrier (BSA-NPs) was performed by the particle size distribution analysis, transmission electron microscopy (TEM), and zeta potential. The antitumor activity of the CA-BSA-NPs was evaluated by measuring cell viability, apoptosis rate, and gene expression of GCLC, COX-2, and BCL-2 in MCF-7 and Caco-2. The cytotoxicity assay (MTT) showed elevated antitumor activity of CA-BSA-NPs against MCF-7 and Caco-2 compared to free CA and BSA-NPs. Moreover, apoptosis test data showed an arrest of the Caco-2 cells at G2/M (10.84%) and the MCF-7 cells at G2/M (4.73%) in the CA-BSA-NPs treatment. RT-PCR-based gene expression analysis showed an upregulation of the GCLC gene and downregulation of the BCL-2 and COX-2 genes in cells treated with CA-BSA-NPs compared to untreated cells. In conclusion, CA-BSA-NPs has been introduced as a promising formula for treating breast and colorectal cancer.