Round Particles Research Articles

Processing and Characterization of Spent Nickel-Metal Hydride Type AA Batteries to Recover Valuable Materials (Cobalt, Nickel and Rare Earth Elements).

The experimental research was focused on the investigation of valuable material from spent Ni-MH type AA batteries, namely the metal grid anodes and the black mass material (anode and cathode powder). The materials of interest were analyzed by X-ray fluorescence spectroscopy (XRF), ICP-OES (inductively coupled plasma optical emission spectrometry), optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). The analyzed grids have a high Fe content, but some of them correspond to the Invar alloy with approx. 40% Ni. In the black mass material, round particles and large aggregations were observed by SEM analysis, showing a high degree of degradation. The XRD analysis reveals the presence of only three compounds or phases that crystallize in the hexagonal system: La0.52Ce0.33Pr0.04Nd0.11Co0.6Ni4.4, Ni(OH)2, and La5Ni19. The obtained results provide useful and interesting information that can be used for further research in the recycling and economic assessment of metals from spent Ni-MH batteries.

Occurrence, abundance, and formation of atmospheric tarballs from a wide range of wildfires in the western US

Abstract. Biomass burning emits large numbers of organic aerosol particles, a subset of which are called tarballs (TBs). TBs possess a spherical morphology and unique physical, chemical, and optical properties. They are recognized as brown-carbon aerosol particles, influencing the climate through the absorption of solar radiation. Aerosol particles were collected from wildfire and agricultural-fire smoke sampled by NASA's DC-8 aircraft during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign in the western US from July to September 2019. This study developed an image analysis method using deep learning to distinguish TBs from other round particles that deformed on the substrate, based on the particles' morphological characteristics in transmission electron microscopy images. This study detected 4567 TBs, with most occurring < 10 h downwind of the emissions, and measured their compositions, abundance, sizes, and mixing states. The number fraction, mass fraction, and concentration of TBs in wildfire smoke corresponded to 10 ± 1 %, 10 ± 2 %, and 10.1 ± 4.6 µg m−3, respectively. As the smoke aged for up to 5 h after emission, the TB number fractions roughly increased from 5 % to 15 %, indicating that TBs are processed primary particles. We also observed TBs associated with pyrocumulonimbus (pyroCb) activity and various TB mixing states. This study reveals the abundance, as well as the physical and chemical properties, of a wide range of TBs from various biomass-burning events and enhances our knowledge of TB emissions, contributing to the evaluation of the climate impact of TBs.

Modification of Co3O4 by Al2O3: Influence on the reducibility

In this study, we used a coprecipitation method followed by calcination at 500 °C to synthesize undoped and Al3+-doped Co3O4 nanoparticles with different aluminum fractions (x = Al/(Co + Al) = 1/60, 1/30, 1/15, 1/75, 1/6 and 1/5). An addition of Al3+ ions led to a decrease in the average crystallite size from 29 to 11 nm, and growth of the specific surface area from 28 to 91 m2/g. TEM images indicated round and platelet shapes of the nanoparticles. According to HAADF-STEM combined with EDS elemental mapping, the platelet shape particles are Al3+-enriched, while the round shape particles are Al3+-depleted. The origin of Al3+ distribution over the oxide volume is conditioned by the state of the hydroxide precursor. It was shown by XRD that the coprecipitation yielded homogeneous hydroxides only for Al fractions x = 0 and x = 1/5. For the intermediate compositions, the precursors represent a mixture of Co6(CO3)2(OH)8*H2O and Co0.8Al0.2(OH)2(CO3)0.1*nH2O. On the TPR-H2 profiles, reduction peaks for three (Co,Al)3O4 oxides differing in the Al3+ concentration (y) can be found. Two of these oxides with y = 0 and y = 0.2 are formed from different hydroxides, and third one with y ∼0.05 is the result of their mutual interaction. In situ XRD allowed us to interpret the TPR peaks correctly and showed that the reduction of all the oxides occurs in two steps. In the first step, Co3+ → Co2+, and (Co1-yAly)3O4 oxides transform to (Co,Al)O. In the second step, Co2+ → Co0, and (Co,Al)O is reduced into metallic cobalt. In undoped Co3O4, Co3+ → Co2+ and Co2+ → Co0 reduction steps occur at T1 = 280 and T2 = 325 °C, respectively. For Al-depleted (Co1-yAly)3O4 (y ∼ 0.05 in the interior of particles), both reduction steps shift toward higher temperatures T1 = 305 and T2 = 405 °C, respectively. The reduction of Al-enriched (Co0.8Al0.2)3O4 is more difficult; first and second reduction steps occur at T1 = 345 and T2 = 610−690 °C. Therefore, Al3+ ions have a little effect on the first step and very significantly influence the second one. Additionally, it was shown by TEM that after the reduction at 700 °C metallic cobalt particles were surrounded by the Al-enriched oxide shell. Apparently, that is why the addition of even a small amount of Al3+ ions prevents a quick sintering of metallic cobalt observed for pure Co3O4.

3D characteristic indicator analysis and comprehensive evaluation of manufactured sand particles used in high-performance concrete

Two-dimensional particle morphology indices face challenges in accurately depicting the characteristics of three-dimensional (3D) manufactured sand (MS), which does not effectively guide the selection of MS for high-performance concrete (HPC). This study aimed to obtain a quantified comprehensive evaluation of actual MS particle groups with specific gradations by thoroughly analysing 3D geometric characteristics. Two representative MS samples were selected for exploration, and river sand (RS) was used as the control. A random selection of sand particles was screened on six sieve levels ranging from 0.15 mm to 4.75 mm. Using X-ray computed tomography and associated image processing technologies, 3D models of these particles were generated, and MATLAB was used to extract their 3D morphology information. Subsequently, the change rules and validity of current 3D particle morphology indicators were examined, focusing on shape, angularity, and texture. Moreover, a comprehensive morphology index, Cm, was proposed by considering the effects of gradation and particle shape classification. The results showed that shape indices more accurately reflected particle characteristics, notably, a higher proportion of spheroid particles, a lower aspect ratio, and greater sphericity correlated with improved particle shape; contrary to traditional beliefs, the angularity index suggested that greater roundness did not necessarily equate to more rounded particles owing to the influence of the proportion of spheroid and cubic particles; meanwhile, texture indices showed minimal difference in the mean values of the 3D fractal dimension for the three types of sand. The proposed index Cm effectively differentiated the particle morphology states of the three sands, with higher Cm values indicating superior particle morphology. The smaller the difference between the Cm values of MS and RS, the better substitute of MS for RS.

Carbon Nanotubes an Excellent Targeted Drug Delivery System

Carbon nanotubes, or CNTs, are carbon allotropes with a nanostructure that can have a length-to-breadth proportion more prominent than 1,000,000. These round and hollow carbon particles have exceptional properties that make them possibly helpful in an assortment of nanotechnology applications. CNTs might be joined with a scope of natural components, including proteins, drugs, and nucleic acids, to give bio-functionalities. CNTs come in two assortments: multi-walled (MWNTs) and single-walled (SWNTs). Among its captivating properties are its high viewpoint proportion, strength, lightweight weight, high warm conductivity, and electrical attributes that reach from metallic to semiconducting. Carbon nanotubes might be made by various cycles, including warm blend, substance fume statement, laser removal, circular segment release dissipation, plasma-based union, and synthetic fume affidavit increased by plasma. Carbon nanotubes (CNTs) track down use in drug conveyance, blood malignant growth, bosom disease, cerebrum malignant growth, liver malignant growth, cervical malignant growth, quality treatment, resistant therapy, biomedical imaging, biosensors, and tissue designing. The noncovalent functionalization of specific MNTs with folic corrosive (FA) worked on the vehicle of medication to malignant growth cells in the lymph hubs. By utilizing a remotely introduced magnet to guide the medication lattice to the provincial designated lymph hubs, the MNTs can ceaselessly deliver chemotherapeutic medications for a few days while remaining in the depleting designated lymph hubs. Growth cells communicating folate receptors (FRs) in the lymph hubs can be explicitly obliterated since FRs are overexpressed in different human malignancies.

Synthesis, evaluation, and biocompatibility study of magnetite nano particles in normal cells and cancer cells for health care application

Magnetic nanoparticles have been synthesized in a very simple and economical way by the co-precipitation method, where the effect of molar concentrations of ferric chloride anhydrous (FeCl3) and iron (II) sulphate heptahydrate (FeSO4.7 H20) on magnetite synthesis has been investigated. Also, a detailed study was conducted to study the effect of magnetite and hematite on both normal and cancerous cell lines. After this, the magnetic nanoparticles obtained were analyzed by x-ray Diffraction (XRD), scanning electron microscope (SEM) - energy dispersive x-ray (EDX), Fourier transform infrared spectroscopy (FTIR), zeta potential, vibrating sample magnetometer (VSM), atomic force microscopy (AFM), MTT test, and cell apoptotic assay. The XRD peaks for magnetite were easily discernible in the final formulation. SEM images showed round particles in nano ranges, and FTIR peaks showed the presence of magnetite. Zeta potential showed surface charges. VSM showed the magnetic property of magnetite, and AFM confirmed SEM images. It can be concluded that magnetic nanoparticles were synthesized by the co-precipitation method using an optimized molar concentration of reagents. Also, the necessity of coating uncoated magnetic nanoparticles can be seen from the MTT assay. Cell apoptotic assays have shown that synthesized magnetite nanoparticles have shown potential apoptotic activity on cancer cell lines.

Laboratory study into engineering characteristics of siliciclastic sedimentary sand

Diverse applications and tremendous usefulness of siliciclastic sedimentary sands make investigation into their mechanics of behaviour very essential globally. This study examines the convergence or otherwise of the specimens in compression; physical, fabric, chemical and mineralogical characteristics and their relationships with compression behaviour; shape characteristics, possible particle breakage and their overall effect on the behaviour of siliciclastic sedimentary sands obtained from two locations. The findings are as follows; (a) Siliciclastic sedimentary sands are poorly graded and coarse in nature. (b) The fabrics are characterized by aggregation of sub rounded particles and smaller particles tend to combine with fines to form coatings around bigger particles. (c) Chemical compositions are predominantly silica and alumina and heamatite are significant. (d) Quartz dominates the mineralogy and the other minerals are muscovite, albite, orthoclase and chlorite. (e) The samples have convergent behaviour and the compressibility is not significantly different but lower than the related materials. (f) The original particle is sub round in shape and the particles become sub angular after the test with no relationship between particle shape and compression behaviour. (g) The particle breakage is linked to coarser nature of the specimens and the overall effect of particle breakage on the compression behaviour of siliciclastic sedimentary sand is small.

Leucine as a Moisture-Protective Excipient in Spray-Dried Protein/Trehalose Formulation

The incorporation of leucine (Leu), a hydrophobic amino acid, into pharmaceutically relevant particles via spray-drying can improve the physicochemical and particulate properties, stability, and ultimately bioavailability of the final product. More specifically, Leu has been proposed to form a shell on the surface of spray-dried (SD) particles. The aim of this study was to explore the potential of Leu in the SD protein/trehalose (Tre) formulation to control the water uptake and moisture-induced recrystallization of amorphous Tre, using lysozyme (LZM) as a model protein. LZM/Tre (1:1, w/w) was dissolved in water with varied amounts of Leu (0 - 40%, w/w) and processed by spray-drying. The solid form, residual moisture content (RMC), hygroscopicity, and morphology of SD LZM/Tre/Leu powders were evaluated, before and after storage under 22°C/55% RH conditions for 90 and 180 days. The X-ray powder diffraction results showed that Leu was in crystalline form when the amount of Leu in the formulation was at least 20% (w/w). Thermo-gravimetric analysis and scanning electron microscopy results showed that 0%, 5%, and 10% (w/w) Leu formulations led to comparable RMC and raisin-like round particles. In contrast, higher Leu contents resulted in a lower RMC and increased surface corrugation of the SD particles. Dynamic vapor sorption analysis showed that partial recrystallization of amorphous Tre to crystalline Tre·dihydrate occurred in the 0% Leu formulation. However, adding as little as 5% (w/w) Leu inhibited this recrystallization during the water sorption/desorption cycle. In addition, after storage, the formulations with higher Leu contents showed reduced water uptake. Instead of observing recrystallization of amorphous Tre in 0%, 5%, and 10% (w/w) Leu formulations, recrystallization of amorphous Leu was noted in the 5% and 10% (w/w) Leu formulations after storage. In summary, our study demonstrated that the addition of Leu has the potential to reduce water uptake and inhibit moisture-induced recrystallization of amorphous Tre in the SD protein/Tre powder system.

Characterization of silver nanoparticles (AgNPs) synthesized using polyphenolic compounds from Phyllanthus emblica L. and their impact on cytotoxicity in human cell lines

The Phyllanthus emblica L. highly medicinal value used for jaundice, anticancer, antioxidant, antiviral, antimicrobial etc., activities so for that current research explored the application of nanotechnology in developing anticancer strategies through the synthesis of silver nanoparticles (AgNPs) using natural extracts from leaves. Various characterization techniques were employed to assess the anticancer properties against the human MCF-7 Breast Cancer Cell Line. This study in UV‒visible spectroscopy AgNPs detected at 436 nm, FT-IR analysis indicated the presence of specific functional groups with high peak intensity at 3105 cm−1. In SEM measurements revealed synthesized AgNPs at 25.4 nm, TEM exposed perfectly round particles with a lattice spacing of 0.295 nm, and XRD analysis revealed reflections at (111), (200), (220), and (310) with corresponding 2θ values of 39.1°, 46.1°, 68.7°, and 79.2°, respectively, along with the observation of (311). EDX analysis confirmed the composite nature of quartz with AgNPs at a 50:50 ratio. Atomic force microscopy (AFM) images of AgNPs 30 nm in size. Furthermore, breast cancer one of the major disease, targeted application of our study focused anticancer activity against MCF-7 breast cancer cell line, observed that plant extract exhibits 92% cancer cell death at 500 µg/ml, showed potential anticancer activity against breast cancer cells. In flowcytometry cancer cells phase distribution was observed at AgNPs (100 to 200 µg/ml). Prolonged exposure to the extract led to cell death and arrested the apoptotic cell death cycle after 24 hours. Research has also evaluated the potential of nanoparticles to inhibit cancer progression, revealing promising prospects for enhancing anticancer therapies. During the treatment against cancer cells observed cell deaths, concluded that green, nanotechnology potential tool for modern world.

The Effect of High-Temperature Deformation on the Mechanical Properties and Corrosion Resistance of the 2024 Aluminum Alloy Joint after Friction Stir Welding.

The 2024 aluminum alloy is one of the high-quality lightweight materials. Friction stir welding (FSW) has shown advantages in reducing welding defects and improving welding quality in 2024 aluminum alloys. Currently, the research regarding FSW joint corrosion performance is mainly about the joint without plastic deformation. However, FSW joints often need to be formed into complex shapes by plastic deformation. The influence of plastic deformation on the corrosion performance of FSW joints is the focus of scientific research. To address this problem, the effect of high-temperature deformation on the mechanical properties and corrosion behavior of 2024 aluminum alloy joints was researched. The exfoliation corrosion test, scanning electron microscopy, energy-dispersive spectroscopy, and transmission electron microscopy were employed to analyze the corrosion mechanism and microstructure. The results show that high-temperature deformation of the weld nugget zone greatly affects the mechanical properties and corrosion behavior of the FSW joint. Compared with the 0% deformation specimen, the hardness and tensile strength of the 20% deformation FSW joint increased by 32% and 21%, respectively. The FSW joint with 20% deformation shows the best mechanical properties and corrosion resistance. The number of precipitated S' phases of the FSW joint increases when the deformation increases to 20%, and the shape of the S' phase is a regular round particle shape. The dislocation density of the FSW joint increases continuously during deformation, which provides a favorable nucleation location for the S' phase.

Development of posaconazole nanocrystalline solid dispersion: preparation, characterization and in vivo evaluation

Objective Posaconazole (PCZ) is an antifungal drug, which acts by inhibiting the lanosterol-14α-demethylase enzyme. It is a biopharmaceutical classification system class II drug with its bioavailability being limited by poor aqueous solubility. The aim of this study was to improve the oral bioavailability of PCZ by preparing nanocrystalline solid dispersion (NCS). Methods PCZ-NCS was prepared by a combination of precipitation and high-pressure homogenization followed by freeze-drying. Several different surfactants and polymers were screened to produce NCS with smaller particle size and higher stability. Results The optimized NCS formulation containing 0.2% Eudragit S100 and 0.2% SLS was found to provide the average particle size of 73.31 ± 4.7 nm with a polydispersity index of 0.23 ± 0.03. Scanning electron microscopy revealed the preparation of homogeneous and rounded particles. Differential scanning calorimetry and X-ray diffraction confirmed crystalline nature of NCS. Nanonization increased the saturation solubility of PCZ by about 18-fold in comparison with the neat drug. Intrinsic dissolution study showed 93% dissolution of PCZ within the first 10 min. In vivo pharmacokinetic study in Wistar rats showed that Cmax and AUCtotal of PCZ-NCS increased by 2.58- and 2.64-fold compared to the marketed formulation. Conclusion PCZ-NCS formulation presents a viable approach for enhancing the oral bioavailability of PCZ.

A preliminary study on calcifying nanoparticles in dental plaque: Isolation, characterization, and potential mineralization mechanism.

Calcifying nanoparticles (CNPs), referred to as nanobacteria (NB), are recognized to be associated with ectopic calcification. This study aims to isolate and culture CNPs from the dental plaque of patients with periodontal disease and investigate their possible role in unravelling the aetiology of periodontal disease. Supragingival and subgingival plaques were sampled from 30 periodontitis patients for CNPs isolation and culture. Alkaline phosphatase (ALP) content changes were tracked over time. Positive samples underwent thorough morphological identification via hematoxylin and eosin (HE) staining, Alizarin red S (ARS), and transmission electron microscopy (TEM). The chemical composition of CNPs analysis involved calcium (Ca) and phosphorus (P) content determination, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The subgingival plaque dental group exhibited a higher CNPs isolation rate at 36.67% (11/30) compared to the supragingival dental plaque group at 66.67% (20/30). ALP activity varied among the positive, negative and control groups. Morphological observation characterized the CNPs as round, oval, and ellipsoid particles with Ca deposits. Chemical analysis revealed the Ca/P ratio was 0.6753. Hydroxyl, methyl, carbonate, phosphate, hydrogen phosphate, and dihydrogen phosphate were detected by FTIR; the main chemical components detected by XRD were hydroxyapatite and tricalcium phosphate. CNPs were found in periodontitis-related dental plaque and exhibited the potential to develop calcified structures resembling dental calculus. However, the potential involvement of ALP in CNPs formation requires deeper exploration, as does the precise nature of its role and the interrelation with periodontitis demand a further comprehensive investigation.

Kinetic evaluation of the uranyl peroxide synthetic route on morphology

Abstract An important challenge in utilizing particle morphology in nuclear forensic or fuel fabrication applications is understanding why differences in morphologies are observed following varying processing conditions. This is often due to competition and interplay between thermodynamic and kinetic influences. To that end, some of the kinetic influences in the uranyl peroxide precipitation reaction were evaluated and compared to thermodynamic influences studied previously. Metastudtite (UO2O2·2H2O) was synthesized from solutions of uranyl nitrate or chloride, and the reaction time was varied from 100 s to 230 min enabling an evaluation of kinetic and thermodynamic influences. The metastudtite was then calcined to U3O8, and all materials were analyzed by powder X-ray diffraction (p-XRD) and scanning electron microscopy (SEM). Analysis by p-XRD confirmed the sample purity of metastudtite and U3O8. SEM images were analyzed using the Morphological Analysis for Materials (MAMA) software to measure the size and shape of the nanoparticles for a statistical comparison between materials. Metastudtite produced at shorter reaction times exhibited a kinetically controlled shape by forming smaller and rounder particles than metastudtite produced at longer reaction times. Metastudtite produced at the longer reaction times exhibited differences between the uranyl nitrate and uranyl chloride routes with the nitrate exhibiting a more angular and faceted morphology than the chloride. Overall, the control of the supersaturation ratio (S) played a significant role in determining the morphology of the metastudtite. Morphological differences between the U3O8 confirmed the role of nanoparticle agglomeration in forming larger sintered particles. The results help demonstrate the importance of understanding particle formation mechanisms in the long-term development of morphology in nuclear forensics or in developing advanced fuels with specific characteristics.

Preparation and In Vitro Characterization of Lactococcus lactis-Loaded Alginate Particles as a Promising Delivery Tool for Periodontal Probiotic Therapy.

Probiotic microorganisms are used in a variety of food supplements and medical formulations to promote human health. In periodontal therapy, probiotics are mainly used in the form of gels, tablets or rinses that often tend to leak from the periodontal pocket, resulting in a strongly reduced therapeutic effect. In this pilot in vitro study, we present biodegradable alginate-based particles as an alternative, highly efficient system for a periodontal delivery of probiotic bacteria to the inflammation site. For this purpose, Lactococcus (L.) lactis was encapsulated using a standardized pump-controlled extrusion-dripping method. Time-dependent bacterial release in artificial saliva was investigated over 9 days. The effect of freeze drying was explored to ensure long-term storage of L. lactis-loaded particles. Additionally, the particles were bound to dentin surface using approved bioadhesives and subjected to shear stress in a hydrodynamic flow chamber that mimics the oral cavity in vitro. Thus, round particles within the range of 0.80-1.75 mm in radius could be produced, whereby the diameter of the dripping tip had the most significant impact on the size. Although both small and large particles demonstrated a similar release trend of L. lactis, the release rate was significantly higher in the former. Following lyophilization, particles could restore their original shape within 4 h in artificial saliva; thereby, the bacterial viability was not affected. The attachment strength to dentin intensified by an adhesive could resist forces between 10 and 25 N/m2. Full degradation of the particles was observed after 20 days in artificial saliva. Therefore, alginate particles display a valuable probiotic carrier for periodontal applications that have several crucial advantages over existing preparations: a highly stable form, prolonged continuous release of therapeutic bacteria, precise manufacturing according to required dimensions at the application site, strong attachment to the tooth with low risk of dislocation, high biocompatibility and biodegradability.

Effect of nano-ZnO on the microstructure and application properties of styrene-butadiene-styrene modified asphalt

In order to further improve the road performance of SBS (styrene-butadiene-styrene) modified asphalt, nano-ZnO (zinc oxide nanoparticles)/SBS/asphalt composites with different nano-ZnO contents were prepared by solution casting method. Temperature scanning and frequency scanning were used to study the rheological properties of the modified bitumen, and the effect of nano-ZnO on the thermal stability of modified asphalt was analyzed by DSC (differential scanning calorimeter). By analyzing the microstructure, it was found that with the addition of nano-ZnO, the SBS gradually transformed from round particles to three-dimensional mesh structure, and the special effect of nanoparticles improved the dispersion of SBS in asphalt, and the formation of the three-dimensional mesh structure was the key to improve the performance of the asphalt application. All the results show that the modified asphalt has the best performance when the doping of nano-ZnO is 2 wt%. Meanwhile, the prepared solution can be electrostatically spun to obtain oriented asphalt fibers with a diameter of 20 µm, which may have applications in areas such as waterproof fabrics or asphalt-based carbon fibers.

Recovery of residual polyamide (PA12) from polymer powder bed fusion additive manufacturing process through a binder jetting process

PurposeThis study aims to propose the reuse of PA12 (powder) in another AM process, binder jettiinng, which is less sensitive to the chemical and mechanical degradation of the powder after multiple cycles in the laser system.Design/methodology/approachThe experimental process for evaluating the reuse of SLS powders in a subsequent binder jetting process consists of four phases: powder characterization, bonding analysis, mixture testing and mixture characteristics. Analyses were carried out using techniques such as Fourier Transform Infrared Spectroscopy, scanning electron microscopy, thermogravimetric analysis and stress–strain tests for tension and compression. The surface roughness, color, hardness and density of the new mixture were also determined to find physical characteristics. A Taguchi design L8 was used to search for a mixture with the best mechanical strength.FindingsThe results indicated that the integration of waste powder PA12 with calcium sulfate hemihydrate (CSH) generates appropriate particle distribution with rounded particles of PA12 that improve powder flowability. The micropores observed with less than 60 µm, facilitated binder and infiltrant penetration on 3D parts. The 60/40 (CSH-PA12) mixture with epoxy resin postprocessing was found to be the best-bonded mixture in mechanical testing, rugosity and hardness results. The new CSH-PA12 mixture resulted lighter and stronger than the CSH powder commonly used in binder jetting technology.Originality/valueThis study adds value to the polymer powder bed fusion process by using its waste in a circular process. The novel reuse of PA12 waste in an established process was achieved in an accessible and economical manner.

Continuously compressing crushing towards a dry processing method, a testing for graphite ore

In this study the comminution methods of graphite bearing ore were compared by using five different crushing methods, namely a jaw crusher, a roll crusher, uniaxial compression tests, and a new type of continuously compressing crushers. These new continuously compressing crushers were available in laboratory and pilot scales. The particles in the + 1700 µm size class produced by continuously compressing crushing were coarser and rougher in texture compared to the rounded particles produced traditionally by a jaw crusher. In the size class −100 µm, most of the graphite flakes were observed independently in the products of each of these crushing methods. The liberation of ultra-coarse-grained graphite flakes in size class + 300 µm was most observed after pilot-scale continuously compressing crusher. The shape and enrichment of the graphite flakes were very similar after both laboratory and pilot scale continuously compressing crushers. In contrast, the graphite flakes produced by jaw crusher appeared as broken particles in the form of accumulation of several layered and non-independent graphite flake structures. The results of this study demonstrate that the new innovative continuously compressing crushing method enables the enrichment of coarser and cleaner graphite, which has a much higher value and wider industrial applications compared to amorphous and fine-grained graphite.

Antioxidant and Physical Characteristics of Anthocyanin Extract from Purple Yam (Dioscorea alata L.) Nanoencapsulation: Effect of Maltodextrin and Whey Protein Isolate Ratios

Anthocyanins are bioactive compounds with antioxidant, anti-inflammatory, and anti-diabetic activities. This bioactive compound is susceptible to changes in temperature and pH conditions. Its use in food products is also limited. Therefore, protection efforts that can bring anthocyanins into the food system through encapsulation are needed. Encapsulation is a technique for protecting bioactive compounds by coating the mixtures using biomaterials. The spray drying encapsulation process does not require difficult preparation and has good protection capabilities. The goal of this study was to investigate the encapsulating properties of the ratio of whey protein isolate to maltodextrin. This study used maltodextrin : whey protein isolate ratios (MD: WPI) 1:3, 1:1, and 3:1 (w/w). Anthocyanin extract was added 30% (w/w). The mixtures were powdered by drying them with a spray drier. The results showed that MD: WPI = 1:3 can retain more bioactive components than other treatments. The characteristics of nanoencapsulants in antioxidant activity, total phenol content, and anthocyanin were 65.16 + 2.87 %RSA, 776.25 + 45.23 mg GAE/100 g, 60.83 + 1.56 mg/100 g, respectively. The nanoencapsulations had irregular round morphology, particle size and zeta-potential were 301.3 nm and -31.9 mV, respectively. Therefore, anthocyanin encapsulation from purple yam extract was successfully produced with lower-cost material for food and pharmaceutical use.

Shear failure analysis of slip zone soil with different coarse particle shapes: Visualized shear test and PIV technology

Coarse particle shape in slip zone soil influences the mesoscopic structure of the soil, which in turn affects soil shear strength and failure behavior. In order to investigate the effect of particle shape on the shear characteristics of coarse–fine-grained mixed slip zone soil, three types of coarse particles (spheroidal, rounded, and angular) were selected for mixing and matching, and a total of 10 sets of medium-scale shear tests were designed for this paper. To quantify the shear deformation and failure process of slip zone soils, particle image velocimetry (PIV) technology and the hanging hammer method were used to obtain mesoscopic data of the soil (displacement vector data of soil particles and elevation data of the shear failure surface), which were used to calculate shear band thickness, shear dilatation, and roughness coefficient of the shear failure surface. The results indicate that coarse particle shape can considerably affect the macroscopic mechanical properties (internal friction angle and shear strength) and mesoscopic deformation characteristics (shear band thickness, shear dilatation, and shear surface morphology) of soils. Angular coarse particles have higher interlocking strength than spheroidal and rounded coarse particles, allowing angular coarse-grained slip zone soils to develop large shear band thickness and rough shear failure surfaces. In addition, mesoscopic damage analysis suggests that the damage rate of slip zone soils decreases with increasing coarse particle shape complexity. These findings enhance comprehension of the failure characteristics of soil-rock mixture slopes and serve as a good reference for the stability analysis of similar slopes.

Understanding the Influence of the Buoyancy Sign on Buoyancy-Driven Particle Clouds

A numerical model was developed to investigate the behavior of round buoyancy-driven particle clouds in a quiescent ambient. The model was validated by comparing model simulations with prior experimental and numerical results and then applied the model to examine the difference between releases of positively and negatively buoyant particles. The particle cloud model used the entrainment assumption while approximating the flow field induced by the cloud as a Hill’s spherical vortex. The motion of individual particles was resolved using a particle tracking equation that considered the forces acting on them and the induced velocity field. The simulation results showed that clouds with the same initial buoyancy magnitude and particle Reynolds number behaved differently depending on whether the particles were more dense or less dense than the ambient fluid. This was found even for very low initial buoyancy releases, suggesting that the sign of the buoyancy is always important and that, therefore, the Boussinesq assumption is never fully appropriate for such flows.