Particle Size Characteristics Research Articles

Impact of Particle Size on the Setting Behavior of Tricalcium Silicate: A Comparative Study Using ISO 6876 Indentation Testing and Isothermal Induction Calorimetry.

This study examines the impact of particle size on the setting behavior of tricalcium silicate powders. The setting behavior was evaluated using ISO 6876 indentation testing and isothermal induction calorimetry techniques. The objective was to compare the outcomes obtained from these methods and establish a correlation between particle size and setting characteristics. The cement pastes were manually mixed with a water-to-solid ratio of 0.66 for conducting indentation tests according to ISO 6876, while calorimetry measurements were performed using isothermal (conduction) calorimetry at room temperature. The findings demonstrate a significant influence of smaller particle sizes on accelerating the hydration process of cement pastes, resulting in a reduction of setting time by up to 24%. Moreover, the final setting times obtained through the indentation method closely approximate the inflection points of the acceleration curves acquired by calorimetry, with time deviations of less than 12% regardless of particle size.

PM1, PM2.5 and PM10 size fraction distribution under steady-state conditions in a walk-in type 222Rn calibration chamber facility.

Attachment of 222Rn progenies, upon their formation, to the atmospheric aerosols and inhalation of these radioactive aerosols causes inhalation dose to the human being. Aerosols have the characteristics of small particle size, long-time suspension and long-distance transmission and easy access to the deep respiratory tract. Aerosols are responsible for viral infection risk such as the recent worldwide pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, or COVID-19). Understanding the formation and behaviour of aerosols in a confined environment in various human habitations is essential to combat such detrimental exposures. Experiments have been performed to study the distribution of aerosol size fractions in the walk-in type 222Rn calibration chamber. The real-time applied particle technology monitors (APT-Maxima stationary monitors) were used for the simultaneous measurements of PM1, PM2.5, and PM10 size fractions. The variation of the mass densities (μgm-3) of different size fractions at different positions inside the chamber was monitored by placing APTs. The PM1, PM2.5, and PM10 sizes fractions were distributed homogeneously within the chamber volume and the concentration ratios of these fractions were 1:1.5:1.6 for concentration values of < 1500μgm-3, and 1:7:9 for the concentration values of > 1500μgm-3.

Preparation and properties of metakaolin-fumed-silica geopolymer modified with sodium silicate and potassium silicate activators

Geopolymers, which are environmentally friendly materials with aluminosilicates as raw materials, are expected to replace cement in construction materials. Here, the effect of fumed silica (FS) on the properties of metakaolin (MK)-based geopolymer materials was investigated with MK, sodium silicate, and potassium silicate as the main raw materials; their microstructures were characterized, and their performance was tested. The geopolymer's compressive strength, particle size, and curing characteristics were measured with X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy for microstructural analysis. The total dissolved solids (TDS) method was employed to study the geopolymer and evaluate the effect of the resulting gel products on TDS. The results revealed that the strength of 4% FS could reach 56.3MPa after 7 days of incorporation, and the strength increased by 20% and 12% compared with the 0% and 2% groups, respectively. Meanwhile, studying the microstructure of kaolin revealed that the best mechanical and physical properties were obtained when kaolin was calcined at 700°C. In addition, the mixture of alkaline activators increased the reactivity of MK, and the mixed alkaline-excited geopolymer from sodium silicate and potassium silicate exhibited enhanced matrix strength properties compared to the single alkaline activators. Overall, the inclusion of the FS material resulted in the optimization of the mechanical properties, confirming the improvement in the mechanical properties.

Synthesis of magnesium oxide and zinc oxide powders in a glow discharge plasma at atmospheric pressure

Investigation of the processes involved in the synthesis of magnesium oxide and zinc oxide powders using the thermal effects of an atmospheric-pressure glow discharge plasma in an inert gas flow are described. The discharge operates in a repetitively pulsed mode with pulse repetition rate of several tens of kilohertz and pulse duration up to 12 μs, discharge current of 600 mA and voltage up to 300 V. These parameters lead to thermal erosion of magnesium or zinc inserts in a molybdenum crucible. The chemical and phase composition of the erosion products were determined using TEM/EDS and X-ray diffraction analysis, and the composition of the plasma was assessed by optical emission spectrometry. This experimental approach allows fabrication of powders of these metal oxides with characteristic particle size 10–50 nm, and the formation of coatings of these materials in a one-step process.

Enhancing particle size characterization performance through proficiency testing program: result and insights from inter-laboratory comparison

The proficiency testing (PT) for particle size characterization by inter-laboratory comparison was organized by the dimensional metrology department of the National Institute of Metrology Thailand (NIMT). This program aims to enhance and to expand the efficiency and capability of testing laboratories in the field of particle size characterization using various techniques, including atomic force microscope (AFM), transmission electron microscope (TEM), scanning electron microscope (SEM), and dynamic light scattering (DLS). The measurement range covers nanometer to micrometer scale. These instruments are importance for research and development especially to nanotechnology related industries. The PT program was conducted in 2022 where five artifacts were used: monodispersed gold nanoparticle (diameter 20 nm), monodispersed polystyrene particle (diameter 100 nm, 500 nm, and 1500 nm) and monodispersed silica oxide particle (diameter 100 nm). The monodispersed polystyrene particles, diameter 100 nm and 1500 nm are certified reference materials (CRMs). These two artefacts were used as the reference to evaluate accuracy of participant laboratories. The other 3 artefacts are reference material under development. Hence, the assigned values were calculated from consensus among all participants. To evaluate the performance of participant laboratories, En values and z-scores were calculated for each artefact and each measuring technique. The assessment of participant performance through performance scores allows the participant to determine how accurate and how appropriate the measurement results and measurement uncertainties evaluation are. From the results, unsatisfied results can be categorized into three scenarios. First, the measurement uncertainties were not appropriately evaluated. Secondly, measurands obtained from all measuring techniques are not the same. Lastly, the magnification used in microscopy techniques plays a crucial role to resolution and accuracy of size determination.

Design of a Water-Efficient Sand-Based Hydroponic System through Capillary Fluid Dynamics

As the world progresses into the 21st century, water scarcity necessitates innovative water conservation and sustainable approaches to agriculture. This paper presents a novel sand-based hydroponic system that leverages capillary action to enhance watering and water retention efficiency, offering a cost-effective and water-efficient solution for sustainable plant growth. To study the physical characteristics (particle size distribution, capillarity, pore radius, uniformity coefficient, water retention) of the growth medium, a comprehensive particle study of three samples was conducted. Subsequently, a practical trial was employed to validate the proposed approach, which demonstrated promising results for large-scale adoption and use. Furthermore, the study explores potential extensions of the system, including the addition of essential nutrients to the water and investigating alternative set-ups for enhanced versatility and efficiency. By combining theoretical scientific analysis and practical experimentation, this research contributes to the advancement of sustainable agricultural and gardening practices and offers a viable path to mitigate water scarcity and food insecurity challenges.

Evolution from basic to advanced structure of fulvic acid and humic acid prepared by food waste

Fulvic acid (FA) and humic acid (HA) are common polyacids in nature. However, the evolutionary process of their basic and advanced structures is still unclear. FA and HA were separated into five molecular weight components to investigate the process of evolution from small to large molecules. The primary structure analysis showed that FA were rich in CN, COOH and OH content, while HA were rich in (CH2)n, NH2 and CC. Moreover, with the molecular weight increasing, the structures could complement each other to maintain the hydrophilic or hydrophobic balance. The 2D-COS spectroscopy demonstrated that during the growth of FA, COOH, NH2 and OH firstly respond. On the other hand, during the growth of HA, NH2 and (CH2)n firstly respond. In addition, advanced structure of FA was affected by intramolecular hydrogen bonds and π − π interaction. HA was affected by hydrophobic interactions due to the abundance of hydrophobic groups, primarily (CH2)n and benzene rings. 3D conformational fitting and particle size characterization confirmed that the interaction forces determine that FA and HA become tightly and loosely molecules respectively. This study is to further explore the geochemical formation and evolution process of FA and HA molecules.

Investigation on permeability of filter cake with different particle sizes: Experimental and simulation study

Cake permeability is a crucial macroscopic physical property in characterizing filtration behavior for coal slurry. However, there is still no appropriate model derived to establish the essential relationship between the cake permeability and complex particle property. In this study, the three-dimensional microstructures with different particle gradation and porosity were generated using particle discrete element software. The permeability of each constructed model was calculated utilizing Lattice Boltzmann Method (LBM). Simulation result shows that the Kozeny–Carman (KC) model is proper to predict the permeability of porous media with different gradations. When the gradation parameters are not considered, it shows that d30 can best represent the particle size characteristics of the particle systems. When the porosity and average particle size remain unchanged, the permeability increases with the increasing of the non-uniformity coefficient (Cu) and the curvature coefficient (Cc). Moreover, we proposed an analytical expression for the permeability estimation with different gradation characteristics, which contains the parameters that can be easily measured in engineering. Then a set of coal slurry samples with different particle size distributions were selected to conduct the filtration test, the permeability of each sample was measured to compare with the predicted results of the gradation permeability model. It is clear that the KC equation in this case can not calculate the cake permeability effectively. Although the gradation model is relatively appropriate to estimate the cake permeability, its accuracy still needs to be improved by considering the pore structure property to eliminate the effect of constant terms.

Study of the effect of the morphology of initial powders on the structural and dimensional characteristics of SiC-based porous ceramic materials

The realization of the necessary energy-efficient technological solutions for the production of highly porous SiC-ceramic materials requires appropriate research. The results of developing energy-efficient one-step methods for the synthesis of porous SiC-based ceramics and studying the characteristics of the obtained ceramics are presented. The effect of the morphology of initial powders on the synthesized product is considered. Ultrafine silicon carbide powders of two types, identical in characteristic particle size, but quite different in the surface morphology, were used as fillers in the synthesis of experimental samples of porous ceramics. The first one was obtained by the traditional furnace method (SiCf), the second one was synthesized by the technology of self-propagating high-temperature synthesis (SiCshs). It is shown that the particle morphology of initial powder components determines the structural parameters and characteristics of synthesized porous ceramics. The pore space parameters (average pore size, specific surface area, equivalent hydraulic diameter, permeability, etc.) can vary significantly. Porous ceramic materials synthesized on the basis of SiCf have an open porosity of 47%, high liquid permeability (up to 2 mDarcy), overwhelming dominance of α-SiC phase, and a narrow pore distribution with an average pore size of about 1 μm. High open porosity (more than 58 %), highly developed nanostructured pore space surface with an area of more than 12 m2/g, and wider pore size distribution (average pore size — 140 nm) are observed in porous ceramic materials based on SiCshs. The obtained results can be used to improve energy-efficient synthesis technologies and methods for predicting the properties of highly porous SiC-based ceramic materials. This will make it possible to create highly porous SiC ceramics within a priory predicted limits of effective applicability for the processes of ultrafiltration or catalysis.

Size characterization and quantification of E171 titanium dioxide particles in food sauces using spICP-MS

A sample preparation method associated to a single particle inductively coupled plasma mass spectrometry (spICP-MS) analysis was developed to ensure a quantitative characterization of TiO2 particles in food sauces. The method was optimized with a fat sauce matrix for which the pristine E171 additive was available. The highest extracted amount of TiO2 particles was obtained using an ultrasound-assisted dispersion in tetramethylammonium hydroxide (TMAH). TEM analysis confirmed these results, showing that these conditions effectively solubilised the fat matrix. The trueness of the method evaluated using a Ti-free mayonnaise spiked with the E171 additive or the NM-100 reference material (NM-100 RM) proved satisfactory with quantitative mass recoveries (>90%). A good agreement in terms of particle sizes was also obtained between those of the spiked mayonnaise and the TiO2 suspensions used for spiking. However, as also shown in the optimization study, the presence of fatty compounds tended to improve particle dispersion. The application of this procedure to E171 labelled food sauces purchased from the EU market showed concentrations of TiO2 particles in the (0.6 – 6) g/kg range with median diameters between 170 and 320 nm. The TiO2 nanoparticle fraction (size < 100 nm) was evaluated between 2% and 12%, depending on the sample. No titanium was detected in the food sauces not labelled E171. Conclusively, the developed method can provide an efficient and reliable analytical approach for TiO2 particles determination in fat food samples which complies with the EU current regulations.

Promising Larvicidal Effects of Nanoliposomes Containing Carvone and Mentha spicata and Tanacetum balsamita Essential Oils Against Anopheles stephensi.

The use of synthetic pesticides to control the spread of mosquito-borne diseases has causedenvironmental pollution and insecticide resistance in mosquitoes. Developments of new green insecticides havethus received more attention to overcome these problems. Nanoliposomes containing carvone and essential oils were first prepared. The nanoliposomephysicochemical characteristics (particle size, morphology, and successful loading) were then evaluated byDynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), and the Attenuated Total Reflection-Fourier Transform InfraRed (ATR-FTIR) analyses. Larvicidal effects of carvone, Mentha spicata, and Tanacetumbalsamita essential oils were investigated against the main malaria vector, Anopheles stephensi, in non-formulatedand nanoformulated states. The larvicidal effects of nanoformulated states were significantly more potent (7.2 folds, 3.5 folds, and 8folds) than non-formulated states. Nanoliposomes containing M. spicata and T. balsamita essential oils with particlesizes of 175 ± 8 and 184 ± 5 nm showed the best efficacies (LC50 values = 9.74 and 9.36 μg/mL). The prepared samples could be used as new green potent larvicides against An stephensi mosquito infurther field trials. It is also recommended to investigate their efficacies against other mosquitoes.

The impacts of CO2 mineralization reaction on the physicochemical characteristics of fly ash: A study under different reaction conditions of the water-to-solid ratio and the pressure of CO2

Utilizing fly ash (FA) directly to mineralize CO2 and injecting carbon sequestration products into goafs of coal mines is a novel and promising technology. The impact mechanisms of CO2 direct mineralization reactions on the characteristics of key groups, physical phases, surface micromorphology, particle size and pore structure of FA are discussed systematically in detail. The focus is imposed on the impacts of different reaction conditions (water-to-solid ratios and pressures of CO2). Based on the FT-IR, XRD and ESEM-EDS analysis, CO2 is transformed into carbonates of five vibrational models after mineralization and largely sequestered as calcite by portlandite, which forms a passivated layer on the FA surface. The particle size of carbonated FA particles gets smaller and less uniform, and the variation laws of the particle size at full scale are analyzed by particle size intervals. The variation process of the pore can be divided into the dissolution of FA for pore expansion, the low degree of CO2 mineralization reaction for further expanding the pore and the high reaction degree for pore shrinkage. This paper provides theoretical bases for improving the direct CO2 sequestration capacity and research directions for the subsequent application properties of carbon sequestration products.

3D image scanning of gravel soil using in-situ X-ray computed tomography

A typical ground investigation for characterizing geotechnical properties of soil requires sampling soils to test in a laboratory. Laboratory X-ray computed tomography (CT) has been used to non-destructively observe soils and characterize their properties using image processing, numerical analysis, or three-dimensional (3D) printing techniques based on scanned images; however, if it becomes possible to scan the soils in the ground, it may enable the characterization without sampling them. In this study, an in-situ X-ray CT scanning system comprising a drilling machine with an integrated CT scanner was developed. A model test was conducted on gravel soil to verify if the equipment can drill and scan the soil underground. Moreover, image processing was performed on acquired 3D CT images to verify the image quality; the particle morphology (particle size and shape characteristics) was compared with the results obtained for projected particles captured in a two-dimensional (2D) manner by a digital camera. The equipment successfully drilled to a target depth of 800 mm, and the soil was scanned at depths of 700, 750, and 800 mm. Image processing results showed a reasonable agreement between the 3D and 2D particle morphology images, and confirmed the feasibility of the in-situ X-ray CT scanning system.

Targeted delivery of essential oils of Salvia officinalis L to AGS cancer cells using PLA-spermine-PEG-FA

The MTT test was used in this study to evaluate anticancer potential of Salvia officinalis L's essential oil on AGS cells. The results showed that the Salvia officinalis L's essential oil has high potential anticancer activity against AGS cells. To improve the solubility of the essential oil and its targeted administration to AGS cells, poly lactic acid-spermine-poly ethylene glycol-folic acid (PLA-Spermine-PEG-FA) (FPSP) was utilized. For this purpose, Salvia officinalis L's essential oil and silver nanoparticles were encapsulated into the PLA-Spermine-PEG-FA (FPSP) using the solvent diffusion technique. Then, using transmission electron microscope (TEM) and dynamic light scattering (DLS), respectively, morphology, zeta potential, as well as average particle size characteristics of the nanoparticles were evaluated. The FPSP/essential oil nanoparticles (FPSP/EO) were spherical in shape and had an average particle size of 200–300 nm. The mean particle dimensions for both PSP/silver/EO and FPSP/silver/EO nanoparticles assemblies are measured at 236.52 ± 22.64 nm and 248.95 ± 28.17 nm, respectively. The results showed that the zeta potential values for PSP/silver/EO and FPSP/silver/EO were −18.3 ± 0.7 mV and −20.6 ± 1.3 mV, respectively. The results of this test showed that FPSP/Silver/EO significantly reduced the percentage of AGS cell viability better than EO and PSP/Silver/EO. The best treatment in this experiment was FPSP/Silver/EO at a concentration of 50 μL/mL and time 72 h. The minimum value of IC50 in FPSP/Silver/EO was observed as 21.11 μL/mL in 72 h.

Effect of the rotor blade geometry on particle size and energy demand for knife-milled beech chips: Experimental identification and mathematical modelling

Rotor blade geometry (linear and screw) was experimentally identified for particle size characteristics and specific energy demand for knife-milled beech chips (7.8 wt % moisture content). The operational conditions of peripheral speed (6.8–20.4 m s−1) and screen sieve openings (0.75–6 mm) were considered for the knife milling of beech chips. The Rossin-Rammler-Sperling-Bennet model precisely described particle size distribution of comminuted beech chips with its parameters depending on screen sieve, rotor speed and blade geometry in a linear relationship. This relationship allowed the development and calibration of a unique empirical linear model. The model predicted particle size under the conditions considered for each blade geometry with accuracy. Energy demand values between 6.97 and 101.6 kW h t−1 were identified for D50 particle sizes between 0.29 and 2.60 mm. Energy demand was independent of the rotor blade geometry, and it was mainly affected by particle size characteristics, even though speed was also impactful. The linear model obtained allowed the prediction of energy requirements using speed and final particle size with an R2 value of 0.97.

Numerical simulation of dual-layer granular bed filtration based on particle collision rebound effect

This article established a dual-layer granular bed filtration model based on the dust collision rebound effect and investigated the influence of dust properties and filtration air velocity on the collision rebound effect and grade efficiencies of the filter layers. The results indicated that the characteristics of dust particle size, density, and effective Young's modulus had a significant impact on the critical adhesion velocity and collision rebound effect. Large dust particle size, density, and small effective Young's modulus resulted in a larger collision rebound effect. The collision rebound effect led to a decrease in grade efficiencies of each filter layer and the dual-layer granular bed with an increase in filtration velocity. To reveal the impact of the collision rebound effect on the movement of dust in the filter material layer, the trajectory and velocity changes of dust in the granule layer were simulated and calculated. The results show that the collision rebound effect caused the dust to repeatedly collide and rebound within the granular bed, penetrating deeper into the granular bed and increasing dust escape.

Potential of ultraviolet laser pulse-induced current for characterizing the grain size of table sugar

In this work, we proposed a laser-induced current (LIC) method to investigate the grain-size dependence of the plasma of table sugar induced by a nanosecond (ns) pulsed ultraviolet laser in the size range of <180 μm–>550 μm and achieve the lower power consumption in measurement. Under multiple laser irradiations and an external electric field (Vb) of 200 V, the LIC variation's (ΔIp) standard deviation and variance were 0.53 nA and 0.05 nA, respectively, indicating the relatively small systematic error during the testing process. The Vb causes a decrease in the possibility of electron–ion complexation and accelerates the separation, resulting in an increase in ΔIp with Vb. With increasing grain size (diameter D) of table sugar, ΔI demonstrate a valley-like behaviour and 250–380 μm is the critical range Dc where ΔI is very weak and considerably depends on the Vb with the slope of 0.031 nA/V. At D > 550 μm and Vb = 5 V, ΔI intensities monotonically rise by 30 % when D surpasses Dc. In this instance, the energy was the main contributor to the LIC signal during plasma generation and expansion. While D is less than Dc, ΔIp increases by 27 % at D ≤ 180 μm and Vb = 5 V. The yield stress is the main reason for the formation of plasma with high temperature and density in this situation because the sugar behaves like an elastic solid. The reason for such a LIC variation trend was discussed, which can be explained by considering the morphological, thermal and mechanical properties competing with each other. The present result suggests that the LIC method enables non-contact characterisation of sugar particle size at low-power consumption.

PH-dependent release properties of curcumin encapsulated alginate nanoparticles in skin and artificial sweat

Topical skin application of curcumin is challenging due to the low solubility and poor stability, including fast photodegradation, of this bioactive compound. Therefore, curcumin encapsulated alginate (CU-Al) nanoparticles were prepared by the ionic gelation method followed by freeze drying to determine the efficacy of alginate in facilitating curcumin release. Evaluation of the release of curcumin from the encapsulate in the presence of artificial sweat (pH 4.7) and skin (pH 5.5), about which the literature is meagre, was carried out after particle size characterization. CU-Al nanoparticles were in the nano-range (186.8 nm), assimilated a negative zeta-potential value (-15.4 ± 8.13 mV), and displayed a high encapsulation efficiency (94.55 ± 0.53%). The release of encapsulated curcumin at pH 5.5 (max. 64%) and at pH 4.7 (max. 27%) were significantly different. In pH 5.5 and pH 4.7, the release profiles of encapsulated curcumin fitted best with the Weibull (followed an anomalous transport mechanism) and Gompertz (followed a super case II transport mechanism) models respectively, displaying sigmoidal release patterns. Diffusion and polymer relaxation/swelling based release at pH 5.5 and rapid polymer relaxation/erosion based release at pH 4.7 have governed the encapsulated curcumin release. The results indicated that CU-Al nanoparticles may be utilized to facilitate controlled and prolonged release of curcumin in both skin and artificial sweat, thereby functioning as a promising novel delivery vehicle for curcumin. However, skin deposition or penetration may be required for yielding a satisfactory topical administration of curcumin during sweating.

Preparation and Performance Optimization of Micrometer Scale Ba1.2Ca0.7‐xSiO4:0.1Eu2+, xMn2+ for Application in Mini LED

AbstractAs the next generation of display technology, Mini Light‐Emitting Diodes (LEDs) have attracted much attention, among which the phosphor used as the backlight should meet the characteristics of small particle size and high brightness. A series of Ba1.2Ca0.7‐xSiO4:0.1Eu2+, xMn2+ are synthesized by the coprecipitation‐solid state method. Hence, the prepared phosphor has a submicron structure with an average particle size of 1.3 ± 0.9 µm. It can be excited by 365–410 nm, with an emission peak of 616 nm and a half‐peak width of 65 nm. At 150 °C, it exhibits a 94% emission intensity and good thermal stability. From 15% to 29%, the external quantum efficiency (EQE) increases. Therefore, the phosphors are suitable for Mini LED displays with near‐ultraviolet light as the excitation source. This method provides a new idea for the development of novel small particle sizes and narrow‐band emission phosphors.

Influence mechanism of dispersion and agglomeration characteristics of micron/nano carbon dust on its combustion kinetics and explosion process

Due to the widespread use of lithium-ion batteries, evaluations of the flammability and explosive characteristics of carbon dust materials as anodes require attention. Carbon dust often reaches the micron/nano scale, and dust particle state and explosion risk generated in different industrial scenarios are different, which is in urgent need of research. Nanoscale dust has relatively static coagulation properties and shows characteristics of dispersion and reagglomeration under a certain airflow. The particle size characteristics affect its thermodynamic characteristics and various consequence parameters of dust explosion. The oxidation and combustion characteristics are mainly affected by dust particle size distribution characteristics. The apparent activation energy is mainly affected by the proportion of small and medium-sized particles and pre-exponential index factor is mainly affected by the dust overall average particle size and specific surface area. The explosion consequence parameters are affected by the thermodynamic parameters, by the disturbance state, particle distribution degree of dust cloud and other factors, which affect the heat radiation and heat transfer process to some extent resulting in different explosion consequence parameters. Due to the agglomeration characteristics of nano-level dust, the minimum ignition energy and minimum ignition temperature of nano-level dust are generally smaller than that of micron level dust.