Size Distribution Analysis Research Articles

Exploring non-cytotoxic, antioxidant, and anti-inflammatory properties of selenium nanoparticles synthesized from Gymnema sylvestre and Cinnamon cassia extracts for herbal nanomedicine

The increasing need for pharmaceutical agents that possess attributes such as safety, cost-effectiveness, environmental sustainability, and absence of side effects has driven the advancement of nanomedicine research, which lies at the convergence of nanotechnology and medicine. Aims and objectivesThe study aimed to synthesize non-toxic selenium nanoparticles (SeNPs) using Gymnema sylvestre (G. sylvestre) and Cinnamon cassia (C. cassia) extracts. It also sought to develop and evaluate versatile nanomedicine formulations i.e. selenium nanoparticles of G. sylvestre and C. cassia (SeNPs), drug (lupeol) loaded SeNPs (DLSeNPs), drug-loaded and coated (PEG) SeNPs (DLCSeNPs) without side effects. MethodsThe SeNPs formulations were hydrothermally synthesized, loaded with lupeol to improve efficacy, coated with polyethylene glycol (PEG) for targeted delivery, and characterized using UV–Vis spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), zeta potential analysis, size distribution analysis, and X-ray diffraction (XRD). Hemolytic cytotoxicity, 2,2-Diphenyl-1-picrylhydzayl (DPPH), total Reducing power, and total antioxidant capacity (TAC) antioxidant assays, carrageenan-induced paw edema, and histological studies were used to estimate the acute anti-inflammatory activity of the synthesized SeNPs. ResultsThe final form of PEGylated and drug (lupeol)-loaded selenium nanoparticles (DLCSeNPs) exhibited an average particle size ranging from 100 to 500 nm as evidenced by SEM, and Zeta potential results. These nanoparticles demonstrated no cytotoxic effects and displayed remarkable antioxidant (IC50 values 19.29) and anti-inflammatory capabilities. These results were fed into Graph-pad Prism 5 software and analyzed by one-way ANOVA, followed by Tukey's post hoc test (p < 0.001). All nano-formulations exhibited significant overall antioxidant activity, with IC50 values ≤ 386 (p < 0.05) as analyzed by ANOVA. The study's results suggest that G. sylvestre outperformed C. cassia in terms of reducing 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical, potassium ferricyanide, and ammonium molybdate in respective antioxidant assays. As far as anti-inflammatory activities are concerned drug (lupeol)-loaded and PEG-coated G. sylvestre SeNPs exhibited the highest anti-inflammatory potential from all other nano-formulations including drug (lupeol)-loaded and PEG-coated C. cassia SeNPs, as exhibited to reduce the release of pro-inflammatory signals i.e. cytokines and NF-kB, making them innovative anti-inflammatory nanomedicine. ConclusionThe study synthesized lupeol-loaded and PEG-coated SeNPs, showcasing the potential for biocompatible, cost-effective anti-inflammatory nanomedicines. G. Sylvester's superior antioxidant and anti-inflammatory performance than Cinnamon cassia emphasizes medicinal plant versatility.

Experimental study on the dynamic strength characteristics of combined heavy metals contaminated soil with nZVI treatment

Nanoscale zero-valent iron (nZVI), a high-performance nanomaterial, can treat heavy metal contaminants and is extensively employed for in-situ treatment of groundwater and contaminated subsoil. However, there are few studies that indicate trends in the dynamic strength parameters of nZVI-treated soils to assess site safety. In this study, three heavy metal contaminants, Zn(II), Pb(II), and Ni(II), were selected to contaminate virgin soil. The heavy-metal-contaminated soil was treated with nZVI at two concentrations (a low dose and high dose of 0.5% and 2%, respectively) of the soil's dry mass. Analyses of particle size distribution revealed a consistent shift towards larger particles upon nZVI treatment, and the percentage of sand gradually increased. Heavy metal contamination decreased the liquid and plastic limits of the virgin soil, while those of the treated soil increased with nZVI content. The dynamic triaxial results showed significantly lower maximum dynamic shear modulus for MS, MS-LdN, and MS-HdN than for NS. The damping ratios of all samples showed an S-shaped trend. Thus, nZVI has the potential to create cemented structures and immobilize heavy metals. However, its effectiveness is significantly modulated by the initial water content of the soil. While the application of nZVI proves beneficial in immobilizing heavy metal contaminants, careful consideration is imperative under dynamic loading conditions.

Magnetic polyamide 11 powder for the powder bed fusion process by liquid-liquid phase separation and crystallization

Herein, we demonstrate the preparation of magnetic polyamide 11 feedstock powders for powder bed fusion (PBF) using liquid-liquid phase separation and crystallization. By adding magnetic nanomaterials during the precipitation process, the particulate additive is incorporated into the polymer matrix. This enables the production of filled systems at single particle level, which is advantageous in terms of the adjustable magnetic strength and homogeneity of the powder. Thermogravimetric analysis is used to determine the additive content and onset temperature of decomposition of composite powders, where additive-enhancement of PA11 powders with magnetic iron oxide nanoparticles showed a positive influence on the thermal stability of the feedstock. Successive analysis of particle size distribution, shape, colour, crystal structure, magnetic properties and thermal properties of the composite powders are carried out and their properties are discussed with respect to the PBF process. A decrease in particle size, width of the thermal process window and isothermal crystallization time can be attributed to the nucleating effect of the magnetic additive. The PBF processability of the composite feedstock is demonstrated by the production of magnetic tensile bar specimens from additive-enhanced PA11 powders with 1 wt.-% magnetic iron oxide.

Product development and characterization of the Ayurvedic herbo-mineral-metallic compound- Hridayarnava Rasa

BackgroundHerbo-mineral-metallic formulations are an inseparable part of the Ayurveda system of traditional medicine. Hridayarnava Rasa (HR) is a preparation containing metals like copper, sulphur, and mercury in processed forms and other herbs that do not produce toxic effects and adverse drug reactions when taken in appropriate dosage. Ayurveda practitioners use it in treating cardiac diseases like hypertension, cardiotoxicity and many more. The rasa-aushadhis possess characteristics such as rapid efficacy, little dosage required, and extensive therapeutic applicability. Hridayarnava Rasa [AFI Part-1, 20:55] has been employed for the treatment of various diseases from ancient times. A systematic study of these formulations manufacturing is required to maintain their quality, safety, and efficacy is a need of time to protect the immense faith of patients in Ayurveda. ObjectivesThe present study aimed to prepare HR as per standard operating procedures mentioned in the classical text and to characterize it physio-chemically using advanced analytical techniques. Materials and MethodsHR was prepared and physicochemical analyses and assay of elements by ICP-AES were carried out as per Ayurvedic Pharmacopoeia of India (API). Powder X-ray diffraction (XRD), Field emission gun scanning electron microscopy with energy dispersive spectroscopy (FEG SEM, EDAX), CHNS-O analysis, Fourier Transform Infrared Spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), Particle size distribution analysis (PSD) was carried out. ResultsThe XRD analysis of HR showed the presence of unreacted sulphur and sulfides of copper and mercury. FEG SEM revealed the particles in the form of aggregates as nanocrystallites in the range of 100–1000 nm. Elemental analysis showed the presence of copper, sulphur, and mercury in major, along with traces of iron, calcium, sodium, potassium, and magnesium. In FTIR analysis, 18 peaks were observed, which strongly suggests the presence of various organic groups. In the TGA, four peaks were seen, which can be attributed to sulphur volatilization and oxidative changes in mercury. In PSD analysis, 50% of the material was found below 16.40 μm. ConclusionTo establish a piece of fundamental knowledge and ensure uniformity of these rasa-aushadhis, it is imperative to conduct an analysis of their characteristics as per classical texts and modern analytical techniques. Additionally, it is crucial to investigate the significance of each procedural step included in the preparation process. The inferences drawn are helpful as an essential aid for quality assurance and standardization of this herbo-mineral-metallic formulation.

Tailoring Microemulsification Techniques for the Encapsulation of Diverse Cargo: A Systematic Analysis of Poly (Urea-Formaldehyde) Microcapsules.

Cargo encapsulation through emulsion-based methods has been pondered over the years. Although several microemulsification techniques have been employed for the microcapsule's synthesis, there are still no clear guidelines regarding the suitability of one technique over the others or the impacts on the morphological and physicochemical stability of the final particles. Therefore, in this systematic study, we investigated the influence of synthesis parameters on the fabrication of emulsion-based microcapsules concerning morphological and physicochemical properties. Using poly(urea-formaldehyde) (PUF) microcapsules as a model system, and after determining the optimal core/shell ratio, we tested three different microemulsification techniques (magnetic stirring, ultrasonication, and mechanical stirring) and two different cargo types (100% TEGDMA (Triethylene glycol dimethacrylate) and 80% TEGDMA + 20% DMAM (N,N-Dimethylacrylamide)). The resulting microcapsules were characterized via optical and scanning electron microscopies, followed by size distribution analysis. The encapsulation efficiency was obtained through the extraction method, and the percentage reaction yield was calculated. Physicochemical properties were assessed by incubating the microcapsules under different osmotic pressures for 1 day and 1, 2, or 4 weeks. The data were analyzed statistically with one-way ANOVA and Tukey's tests (α = 0.05). Overall, the mechanical stirring resulted in the most homogeneous and stable microcapsules, with an increased reaction yield from 100% to 50% in comparison with ultrasonication and magnetic methods, respectively. The average microcapsule diameter ranged from 5 to 450 µm, with the smallest ones in the ultrasonication and the largest ones in the magnetic stirring groups. The water affinities of the encapsulated cargo influenced the microcapsule formation and stability, with the incorporation of DMAM leading to more homogeneous and stable microcapsules. Environmental osmotic pressure led to cargo loss or the selective swelling of the shells. In summary, this systematic investigation provides insights and highlights commonly overlooked factors that can influence microcapsule fabrication and guide the choice based on a diligent analysis of therapeutic niche requirements.

Computational insights into gas atomization of FeCoNiCrMoBSi high-entropy alloy: From droplet formation to rapid solidification

The intricate processes governing the gas atomization of molten metal droplets and their subsequent solidification hold paramount significance in materials science. Computational fluid dynamics simulations have emerged as indispensable tools for unraveling the complexities inherent in metal melt atomization. This study employed the volume of fluid method and the shear-stress transport k-ω turbulence model to simulate the primary atomization process of a FeCoNiCrMoBSi high-entropy alloy. Subsequently, the discrete phase model and Taylor analogy breakup model, based on the gas Weber number and incorporating primary atomization outcomes as initial conditions, were utilized to simulate droplet formation during the secondary atomization process. Analysis of the particle size distribution at the outlet of the geometric model demonstrated excellent agreement with experimental data for gas-atomized FeCoNiCrMoBSi high-entropy alloy powder. Furthermore, comprehensive characterization analyses were conducted to probe the phase constitution and structure of FeCoNiCrMoBSi powder produced by gas atomization. The results revealed that, irrespective of particle size, the powder exhibited a face-centered cubic structure and distinctive eutectic microstructural characteristics. The numerical simulation provided insights into the solidification process of secondary droplets by integrating inverse pole figure data for gas-atomized powder across varying particle sizes. The estimated cooling rate of secondary droplets ranged from 1.22 × 104 K/s to 2.64 × 105 K/s. These findings significantly advance the understanding of the gas atomization mechanism of the FeCoNiCrMoBSi high-entropy alloy, paving the way for the development of more efficient manufacturing processes for advanced materials.

In-situ rock shattering and strain localization along a seismogenic fault in dolostones (Monte Marine fault, Italian Central Apennines)

In-situ shattered rocks are often associated with seismogenic fault zones, but their mechanism of formation is still matter of debate, partly because of the limited number of field studies. Here we describe the characteristics of in-situ shattered rocks distribution along the NW-SE-striking seismogenic Monte Marine Fault (MMF) in the Italian Central Apennines. In the studied area, the MMF cuts through Mesozoic carbonates, is exhumed from <3 km depth and consists of two >5 km-long major hard-linked segments with normal kinematics. The linkage between the two fault segments occurs along a ∼2 km-long step-over zone with E-W trending faults and oblique-slip kinematics. To the northwest, fault-related shear deformation is localized in a ∼5 m-thick cataclastic fault core and off-fault deformation is dominated by in-situ shattered rocks up to ∼40 m-thick. Instead, in the step-over zone to the southeast, the in-situ shattered rocks are up to ∼500 m thick, particularly where MMF crosscuts older low-angle thrust faults.We integrated detailed field structural surveys with microstructural and grain size distribution analyses of the fault rocks to assess the mechanism of (1) formation of in-situ shattered rocks and, (2) progressive localization of shear deformation along the MMF. The obtained results, after the viability of several formation mechanisms (mechanical models) have been reviewed, support the hypothesis that the formation of in-situ shattered rocks was associated with the propagation of (multiple) seismic ruptures (mainshocks and aftershock sequences) within a mechanically heterogeneous fault zone. Heterogeneity is due to the occurrence of preexisting damage related to previous earthquakes, but also inherited from the older low-angle thrust faults. Therefore, we suggest that the origin of these shattered rocks is more compatible with seismic related processes than only with quasi-static fault growth models. On the other hand, the cataclastic fault core derived from the progressive accommodation of shear deformation within the in-situ shattered rock volumes during several seismic cycles. We conclude that the large volumes of in-situ shattered rocks are the result of seismic-related dissipative processes in a geometrically and mechanically heterogeneous fault zone. In this scenario, large volumes of in-situ shattered rocks are compliant low velocity zones which can influence the propagation of earthquake ruptures.

Partial replacement of hydrogenated oil with beeswax oleogel in whipped cream: Effect on crystallization behavior and foam stability

Long-term consumption of hydrogenated palm kernel oil (HPKO) in whipped-frozen products has been linked to harmful health effects. The aim of this study was to investigate the use of beeswax oleogel as a partial replacement for HPKO in whipped cream. The effect of substitution rate on the lipid crystallization behavior, whipping characteristics, and foam stability of whipped creams was investigated. As the oleogel replaced 30–90% HPKO, the solid fat content decreased, and the growth pattern of the fat crystals shifted from two-dimensional disc-like to one-dimensional linear. Particle size distribution and microrheology analysis revealed that 30% or 60% oleogel substitution facilitated partial coalescence of fat, leading to in a higher elasticity index in emulsions. These results promoted overrun, firmness, and homogeneous bubbles in whipped creams. However, an oleogel substitution rate of 90% resulted in an excessively low overrun and collapse of foam structure. This study proposes an effective solution for constructing a frozen-aerated system that enhances fat partial coalescence and improves foam performance.

Research on the Grinding Process of Superhard Particles in the Fluidized Bed Opposed Jet Mill Based on the CFD-DEM Methodology

The process of superhard particle breakage in the grinding zone of the fluidized bed opposed jet mill is investigated using the CFD-DEM (computational fluid dynamics-discrete element method) coupling method with the Tavares UFRJ Breakage Model in the present study. The effects of structural and operational parameters, such as target plate structure, nozzle position, air inlet velocity, and feed rate, on the equipment stress distribution, airflow velocity, pressure field, particle velocity, and cumulative particle size distribution are thoroughly studied to determine the optimal structural and operational parameters. Experimental validation is conducted, including scanning electron microscope (SEM) observation of particle morphology and analysis of particle size distribution of ground product particles. The simulation results indicate that the wear rate of the structure without a target plate is lower than that of the structure with a target plate in the grinding central zone. Therefore, the structure without a target plate is chosen for further investigation. The cumulative particle size distribution after grinding is influenced by nozzle position, air inlet velocity, and feed rate. The particle D50 is positively correlated with nozzle spacing and feed rate, while it is negatively correlated with air inlet velocity. The optimal grinding effect is achieved when the distance between the nozzle and the center of the grinding zone ranges from 52.5 mm to 72.55 mm, the air inlet velocity is 950 m/s, and the feed rate is 10.5 g/s. Through experimental investigation, it has been observed that when the feed rate is 10 g/s, the particle size distribution becomes more uniform. Furthermore, consistent trends in the cumulative particle size distribution in the experiment and simulation results can be found, which validates the present numerical model. It was observed that particles at low feed rates retain certain angular edges, while particle roundness increases at high feed rates.

Design and Implementation of Large-Scale Hard Rock AMD Dewatering and REE Production

To develop a domestic Rare Earth Elements (REE) supply chain the Hydraulic Preconcentrate (HPC) produced at the Horseshoe bend treatment plant (HSB) was evaluated as a potential source for feedstock. After the clarifiers were flipped to the desired pH set points, a total of 24 Geobags were repeatedly filled and allowed to passively dewater. The Geobags evaluated were comprised of a mix of Woven, Non-woven, and Capillary Channel Fiber (CCF). The bags were constructed with either a composite of woven and nonwoven or only woven geotextile. Half of the bags of both types also included “fins” made of CCF to evaluate their impact on dewatering. Column Filtration Tests (CFTs) were performed onsite to provide laboratory value for hydraulic conductivity. Throughout their dewatering, the geobags were sampled to determine their rate of dewatering. Influent samples from HSB were also tested to produce a Specific Gravity (Gs), via pycnometer testing and Grain Size Distribution (GSD), via sieve and hydrometer analysis. The dewatering ability of the geobags was high regardless of bag material with a mean total solids percentage of approximately 40% across all samples after only one month of dewatering. The GSD performed on the HPC is gap graded with most particles having a diameter of approximately 0.5-0.05mm. Hydraulic conductivity values for the filter cakes during Column Filtration Testing ranged from 0.5 to 2.5 meters/day. This data will help to guide development of future large-scale HPC dewatering and the parametric design of an REE oxide production plant at the HSB site.

Study on the Interaction of Polymeric Chemical Additives with Phase Change Materials in Air Lime Renders.

The interaction of microencapsulated phase change materials (PCMs) with polymeric chemical additives in an air lime binding matrix was studied. These polymer-based additives included an adhesion booster (derived from starch) and a superplasticizer (polycarboxylate ether). Two different PCMs with melting points of 18 °C and 24 °C were assayed. The microcapsules were composed of melamine, with paraffin-based PCM cores. Measurements of zeta potential, particle size distribution, adsorption isotherms, and viscosity analyses were performed to comprehend the behavior of the polymer-based additives within the air lime matrix and their compatibility with PCMs. Zeta potential experiments pointed to the absence of a strong interaction between the lime particles and the microcapsules of PCMs. At the alkaline pH of the lime mortar, the negative charge resulting from the deprotonation of the melamine shell of the microcapsules was shielded by cations, yielding high positive zeta potential values and stable dispersions of lime with PCMs. The polycarboxylate ether demonstrated the ability to counteract the increase in mixing water demand caused by the PCM addition in the lime matrix. The dispersing action of the superplasticizer on the lime particles was seen to exert a collateral dispersion of the PCMs. Conversely, despite the positive values of zeta potential, the addition of the starch-based additive resulted in the formation of large PCM-lime clumps. Air lime renders incorporating 5, 10, and 20% PCMs by weight with various dosages of these chemical additives were experimented with until the optimal formulation for the specific application of the mortars as renderings was achieved. This fine-tuned formulation effectively tackled issues commonly associated with the addition of PCMs to mortars, such as poor adhesion, crack formation, and reduced fluidity.

Pollution and health risk assessment of co-existing microplastics and heavy metals in urban dust of Riyadh city, Saudi Arabia

Microplastics (MPs) and heavy metals have recently attracted much attention due to their widespread distribution in the environment. Co-occurrence of MPs and heavy metals in dust poses potential health risks for humans. The objectives of this study were to investigate pollution and health risk factors associated with co-occurring MPs and heavy metals in urban dust. Here, 20 dust samples (both indoor and outdoor environments) were collected from different places in Riyadh, Saudi Arabia using sweeping method. The MPs were separated from dust samples via density separation using ZnCl2 Microscopic techniques were used to investigate MPs while inductively coupled plasma optical emission spectrometry was used heavy metals analyses in the collected samples. The results of the study showed that all the collected dust samples were contaminated with MPs of different shapes, sizes, and colors. Fragment-shaped MPs were the most dominant, followed by granules, fibers, and lines, while the majority of the MP particles were red and black. Furthermore, the size distribution analyses demonstrated that particles above 1,000 µm were abundant. Also, the number of MPs was in the range of 20 particles g-1 to 1,052 particles g-1. Human exposure estimations showed that toddlers could inhale more MPs (0.86 MPs particles kg-1 day-1 and 312.93 particles kg-1 year-1) than children, teenagers, and adults. In addition, the concentrations of heavy metals varied from one site to another, however, the average concentrations were lower than their corresponding values in the guidelines (except for Zn). The integrated potential ecological risk in dust samples was characterized as a low-risk criterion. The enrichment factor for Zn in dust samples at all sites was more than 2, indicating a major contamination concern and anthropogenic sources responsible for the existence of Zn. The estimated hazard quotient indicates that children and adults are saved from the adverse effects of dust inhalation in the studied area. These findings could serve as a preliminary step for efficient pollution management and environmental quality maintenance in Riyadh.

Detection of Autumnal Concentration of Coscinodiscus granii in the Southern Baltic—A Method for In Situ Measurement of Marine Particles

Efficient means for measuring the abundance and species composition of phytoplankton in situ continue to pose a big challenge to scientists. Hitherto, analyses and interpretations have been based mainly on small numbers of data acquired from microscopic examinations of water samples. Hence, information on devices facilitating such measurements is highly desirable. This paper examines the opportunities offered by the LISST-100X instrument for measuring in situ the concentrations and spatially variable biovolumes of a species dominant in the southern Baltic during the autumnal bloom. Microscopic analysis of phytoplankton in water sampled from different locations in the southern Baltic confirmed earlier results, indicating that this bloom was due to the overriding prevalence of one microplankton diatom species—Coscinodiscus granii. Combining the microscopic measurements of C. granii cell sizes with the size distribution ranges employed by the LISST-100X yielded equivalent spherical diameters (EDSs) ranging from 47.4 to 188.0 µm, with maxima in the 78.4–92.6 and 92.6–109 ranges. Comparative analysis of the particle size distribution (PSD) spectra was used to separate the abundance of C. granii from the total suspended particulate matter (SPM). Spatial in situ measurements in 2012 and 2014 of C. granii concentrations in surface waters showed that both its abundance and its percentage contribution to the total SPM were highly variable. Over a distance of several km, these concentrations varied from values close to zero to 0.2 µL L−1 in 2012 and from 0.3 to 0.9 µL L−1 in 2014, whereas the percentage in the total SPM was found to vary locally from a few to c. 50%. The proposed method and results demonstrate the success of the LISST-100X instrument in detecting size and volume concentrations of phytoplankton in size classes ranging from 1.25 to 250 μm. However, the correct interpretation of LISST data requires that the dominant phytoplankton species concentration in the suspensions be large enough for the signal (peak) to be readily visible against the background PSD of other SPM.

Study of Advanced Techniques for Inquisition, Segregation and Removal of Microplastics from Water Streams: Current Insights and Future Directions

The present research covers different analytical methods utilized for the diagnosis and characterization of microplastics (MPs) in water and wastewater, such as particle size distribution analysis, and focuses on the sources and forms of MPs in receiving environments. First, we look at the most recent collection techniques, which include a variety of spectroscopic, chromatographic, and microscopic approaches used to identify and measure microplastics in water samples. We then investigate separation techniques designed to separate microplastics from diverse environmental matrices. This involves applying existing methods of separation based on density, such as centrifugation, flotation, and sedimentation, as well as more recent ones, like the use of microfluidic devices and materials for selective adsorption. Lastly, we look into removal methods aimed to reduce the buildup of microplastics in aquatic environments. These include enzymatic breakdown, coagulation/flocculation, and filtering, among other physical, chemical, and biological techniques.

Emplacement of shergottites in the Martian crust inferred from three‐dimensional petrofabric and crystal size distribution analyses

AbstractShergottites are mafic to ultramafic igneous rocks that represent the majority of known Martian meteorites. They are subdivided into gabbroic, poikilitic, basaltic, and olivine–phyric categories based on differences in mineralogy and textures. Their geologic contexts are unknown, so analyses of crystal sizes and preferred orientations have commonly been used to infer where shergottites solidified. Such environments range from subsurface cumulates to shallow intrusives to extrusive lava flows, which all have contrasting implications for interactions with crustal material, cooling histories, and potential in situ exposure at the surface. In this study, we present a novel three‐dimensional (3‐D) approach to better understand the solidification environments of these samples and improve our knowledge of shergottites' geologic contexts. Shape preferred orientations of most phases and crystal size distributions of late‐forming minerals were measured in 3‐D using X‐ray computed tomography (CT) on eight shergottites representing the gabbroic, poikilitic, basaltic, and olivine–phyric categories. Our analyses show that highly anisotropic, rod‐like pyroxene crystals are strongly foliated in the gabbroic samples but have a weaker foliation and a mild lineation in the basaltic sample, indicating a directional flow component in the latter. Star volume distribution analyses revealed that most phases (maskelynite, pyroxene, olivine, and oxides/sulfides) preserve a foliated texture with variable strengths, and that the phases within individual samples are strongly to moderately aligned with respect to one another. In combination with relative cooling rates during the final stages of crystallization determined from interstitial oxide/sulfide crystal size distribution analyses, these results indicate that the olivine–phyric samples were emplaced as shallow intrusives (e.g., dikes/sills) and that the gabbroic, poikilitic, and basaltic samples were emplaced in deeper subsurface environments.

Fragmentation energy calculation model of coal crushed by impact load

ABSTRACT Rock fragmentation is a common physical and mechanical phenomenon that exists in a variety of ranges from the mining and processing. Communication is an important operation in coal processing whereby the coal block coming from coalmines is crushed into fragmentations with reduced size, which accounts for 80% of the electricity consumption of mineral processing circuits. Fragmentation energy, which is related to the coal particle size distribution, is an essential parameter for improving the efficiency of shearer, road-header, and crusher. Coal particles are generally simplified into fine or near spherical shapes for analytical and numerical simulation purposes. This research aims to establish the fragmentation energy calculation model for coal fragmentations with coarse and wide size distribution based on the analysis of size distribution and energy-size relationships of coal particles. It has been demonstrated by the results that the fragmentation energy of impact load crushed coal can be determined based on Rittinger’s theory with fractal or RR model particle size distribution.

Assessing phosphorus recovery from anaerobic digestion effluent of tapioca starch processing in a pilot – scale fluidized – bed homogeneous crystallizer: Effects of operation modes

This present study aimed to investigate the effects of two crystallization operation modes, batchwise operation (BO) and continuous operation (CO), on P recovery efficiency and characteristics of precipitates in a pilot – scale fluidized – bed homogenous crystallizer, using real anaerobic digestion (AD) effluent derived from tapioca starch processing as influent. Characterization techniques, including SEM – EDX, powder XRD, profile – matching, FT – IR, and crystal size distribution (CSD) analysis, were employed to identify phase compositions. Additionally, the purity and %P content of the target product were quantified using principles of hierarchical equilibrium thermodynamics and elemental analysis. As a result, the highest P recovery efficiency was 72.5 % for BO and 83.2 % for CO at a pH of 9 and a mixing rate of 400 rpm. Phase identification results revealed that struvite formed with Ca – rich solids, such as hydroxyapatite (HAP), notably exhibited higher impurity levels originating from CO modes. Precipitates from BO modes predominantly held 65 – 75 % struvite, with %P content ranging from 7.4 to 13.1 % — surpassing that of single superphosphate fertilizer (SSP, 18 – 22 % as P2O5), resulting in a suitable process in this study. Moreover, results obtained from the cost – benefit analysis (CBA) highlighted that BO scenario had economic viability (NP +0.05 to +1.53) with an estimate production cost of 3.47 USD/kg Premoved. Hence, the findings not only indicated that real AD effluent is suitable for P recovery, yielding high – quality struvite products, but also contribute to understanding the nuanced impact of crystallization modes on recovery yields and characteristics. This insight is invaluable for optimizing the process, leading to environmental benefits through reduced P and nitrogen discharge.

Comprehensive investigation of recycled PVC powder.

This study constitutes a comprehensive investigation centred on comprehending the behaviour and characteristics of recycled polyvinyl chloride (PVC) powders. The overarching objective is to successfully conclude the initial research phase, during which PVC-coated fabric offcuts undergo a transformation into PVC powder while achieving complete separation from polyethylene terephthalate fibres. The study entails a qualitative description of the morphology of PVC powder particles, employing an optical microscope to distinguish the diverse shapes exhibited by these particles. The optical microscope observations of PVC powder reveal a distinct array of non-spherical particles characterized by flat, elongated shapes. These high-magnification images unveil the intricate morphological features of the particles, highlighting their irregular shapes. Subsequently, a quantitative analysis of PVC particle size distribution is performed, comparing results from optical microscopy with those obtained through mechanical sieving. The qualitative and quantitative findings obtained provide robust evidence supporting the correlation and confirm that most particles are smaller than 600 µm (93.6%) using an optical microscope and the sieving process (96.39%). The greatest fraction (83.44%) is in the size range between 200 and 600 µm. Assessing flowability, another significant aspect in the evaluation of powders, provides insights into its behaviour and interparticle interactions. The flowability results indicate a Compressibility Index of approximately 26.84%, which suggests poor flowability. This means that the powder is likely to encounter difficulties in flowing freely. This finding is in line with the Hausner ratio, which measures 1.37. This investigation of recycled PVC powder will offer insights into the potential applications and processing considerations of this powder. More concretely, the use of recycled PVC powder shows promise as a viable alternative to conventional PVC resin in plastisol formulations, offering the potential to maintain the properties of the final PVC product without adverse effects.

Numerical simulations of bubbly flows in a vertical periodic channel

In this study, numerical simulations of bubbly flows in an infinitely long vertical channel were performed. Generally, the upper and lower boundaries of such channels are simplified as periodic boundary conditions. Unlike horizontal channel flows, the presence of gravity in the streamwise direction complicates the establishment of periodic boundary conditions. Therefore, a specialized treatment is required to prevent fluid acceleration. Here, we developed a novel treatment for the imposition of periodic boundaries and proposed a new microbubble model to consider the surface tension effect of microbubbles. To detect each bubble in the flow field, we implemented a bubble identification algorithm, which facilitates a thorough statistical analysis of bubble number, size, and spatial distribution. Validation tests were conducted, and good agreement was achieved between our results and reference data. We also confirmed that the results obtained with periodic boundaries are consistent with those achieved without them. Finally, we simulated the evolution of rising bubble swarms in a quiescent liquid. The method presented here contributes to the numerical simulations of bubbly flows in industrial systems, including oil-gas transportation, bubble columns, and nuclear reactors.

Separation and Characterization of Nickel Hydroxide from Waste Solution Using Ca(OH)2 Precipitation in Chloride Media

Nickel hydroxide (Ni(OH)2) is a valuable compound derived from nickel, widely utilized across various fields because of its versatile properties. This study aimed to characterize as-prepared β-Ni(OH)2 via chemical precipitation using various analytical techniques. X-ray diffraction (XRD) analysis confirmed the formation of a β-Ni(OH)2 hexagonal crystalline structure, validating the successful precipitation. Fourier-transform infrared spectroscopy (FTIR) spectra exhibited main characteristic peaks of (υOH) and υ(NiO), corresponding to the formation of nickel hydroxide (Ni(OH)2). Subsequently, X-ray photoelectron spectroscopy (XPS) revealed a prominent peak for Ni2+ oxidation, confirming the successful precipitation of nickel hydroxide at pH 6.5, which identifies the existence of impurities, such as chlorine and calcium, from the waste matrix. Scanning electron microscopy (SEM) micrographs demonstrated stratified granules with a nearly pure brucite crystalline phase, typical of β-Ni(OH)2. Furthermore, the surface morphology revealed a coarse texture and uneven clustering, suggesting possible elevated oxide levels on the Ni surface. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of nickel (Ni) and oxygen (O), with Ca impurities attributed to the chemical precipitation process. Particle size distribution analysis estimated an average particle size of 2.0 µm. Additionally, the precipitation of nickel was investigated using inductively coupled plasma optical emission spectroscopy (ICP-OES). Ni was observed in decreasing order, 62.7 g/L, 0.8 g/L, and 0.501 g/L in the pregnant leach, precursor solution, and solid precipitate (cake), respectively. The separation of Ni(OH)2 through the precipitation process from the waste (acidic chloride media) enabled efficient recycling and re-use of nickel, which provides a cost-effective and environmentally friendly method for the highly efficient utilization of waste (acidic chloride media).