Granulated Material Research Articles

Acoustic properties of Helmholtz resonator filled with granulated polymer waste material

This study investigates the acoustic absorption performance of cavity resonators filled with different types of polymer waste material instead of traditional porous material. The absorption spectrum was determined by impedance tube measurements. The data are compared with the ones obtained for the empty resonator and the resonator filled with polyester fiber board. Granulated polymer-filled cavities hold potential applications in construction, particularly as a sound absorber for building facades or noise barriers. This research contributes to the exploration of new sustainable practices within the construction industry. The presented research was performed in the framework of the EU H2020 - MSCA - DN project ActaReBuild.

СТЕНОВЫЕ МАТЕРИАЛЫ ПОЛУСУХОГО ПРЕССОВАНИЯ НА ОСНОВЕ ГРАНУЛИРОВАННЫХ ИЗВЕСТНЯКОВЫХ ОТХОДОВ КАМНЕДОБЫЧИ

this article is devoted to the study of the processes of granulation of raw materials mixtures from limestone waste of stone mining and Portland cement and the production of wall materials based on them by semi-dry pressing. The optimal humidity-time parameters of the manufacture of granules were determined, laboratory samples of wall materials from granular mixtures with different contents of Portland cement were made. It was found that the compressive strength of samples from granulated raw materials exceeds the strength of samples from non-granulated raw materials by 3-12%. Subject of research: semi-dry pressed wall materials based on granular limestone waste from stone mining Materials and methods: Nummilite limestone waste from the Skalistoe deposit (Crimea) and Portland cement PC 500 DO from the Novorossiysk Cement Plant were used for the study. The physical and mechanical properties of the prototypes were determined by standard methods. Results: Experiments have shown that the compressive strength of samples made from granules containing 5-15% Portland cement and 85-95% of stone mining waste exceeds the strength of samples from non-granulated raw materials by 3-12%. Conclusions: The use of granular limestone waste from stone mining as the main component for the production of wall materials by semi-dry pressing makes it possible to increase their strength characteristics. The addition of Portland cement in certain proportions (5-15%) improves the strength characteristics of materials. Further research can be aimed at optimizing the composition of materials, studying their durability and adapting the production process to industrial scales.

Impact of curing conditions on the mechanical properties and micro characteristics of alkali-activated material synthesized from industrial waste soda residue

Alkali-activated materials (AAM) are considered a type of green cementitious material because they are produced without the grinding and calcining required for cement production, significantly reducing carbon emissions. However, their production typically involves the use of commercial alkalis, which are often corrosive, irritating, and expensive. As an industrial waste from sodium carbonate production, soda residue (SR) has a large reserve and is challenging to dewater and utilize, making its disposal a widespread technical challenge. In this paper, considering the alkaline nature and high salt content of SR, a soda residue activated granulated blast-furnace slag cementitious material (SAG) was synthesized directly using undried and unground SR slurry as the alkali activator, with a mass ratio of SR to granulated blast-furnace slag (GBFS) of 30:70. The effects of ambient temperature (AT) curing, water curing, various heat curing temperatures (45°C, 60°C, 75°C, and 90°C), and different heat curing durations (6 h, 12 h, 18 h, and 24 h) on the properties of SAG were investigated. Specifically, the effect of curing conditions on the mechanical properties of SAG was analyzed through unconfined compressive strength (UCS) testing of mortar specimens. The impact of curing conditions on the phase composition and changes in SAG was characterized using XRD, TG, and FTIR, while the effect on the microstructure of SAG was characterized using SEM. The results showed that SAG achieved the highest UCS (3 d/56 d: 28.1 MPa/36.7 MPa) when subjected to heat curing at 75°C for 12 h. The UCS increased significantly by 3022 % and 321 %, respectively, compared to those under AT sealed curing. This was attributed to the fact that SAG under heat curing produced more C-(A)-S-H gels and hydrocalumite crystals, optimizing pore structure and resulting in a denser microstructure. However, exceeding the threshold temperature of 75°C led to an excessively rapid hydration reaction that adversely affected the further dissolution of GBFS and the uniform distribution of hydration products, thereby diminishing the positive effects of heat curing on UCS. In addition, excessively prolonging the heat curing time exacerbated the development of microcracks within the SAG, leading to a deterioration of UCS over age. In this paper, a novel AAM was synthesized using undried and unground industrial waste without the addition of commercial alkali, and the impact of curing conditions on their properties was studied. This broadens the range of applications for SAG, fills a gap in research on the impact of curing conditions on AAM without commercial alkali, and provides a theoretical basis for the low-carbon utilization of industrial waste.

Spark plasma sintering of cenosphere-derived Cs/Sr-aluminosilicates for 137Cs and 90Sr immobilization in mineral-like ceramics

In this study, a promising method of spark plasma sintering (SPS) was investigated for the fabrication of ceramic matrices designed for the reliable immobilization of highly radioactive radionuclides 137Cs and 90Sr. The ceramic matrices were derived from a mixed composition of two aluminosilicate mineral-like phases – pollucite (Cs,Na)AlSi2O6 and gehlenite Sr2Al2SiO7. The originality of the developed approach lies in the utilization of hydrothermal synthesis for obtaining granulated precursor material. Hollow aluminosilicate microspheres (cenospheres) from coal fly ash served as the initial raw material, which were treated with alkaline solutions containing Cs+ and Sr2+ ions as simulants for the corresponding radionuclides. This method facilitated the achievement of high efficiency in cation removal from solutions exceeding 98 %. For a comprehensive examination of the composition and morphology of cenosphere-derived precursor particles, and the influence of sintering temperature on phase and structure formation of ceramic matrices under non-equilibrium conditions of spark plasma heating, various analytical techniques were employed. These included thermogravimetry/differential thermal analysis (TG/DTA), powdered X-ray diffraction analysis (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), as well as the method of low-temperature nitrogen adsorption for determining the specific surface area. The obtained ceramic samples exhibited high values of specific density (2.688–2.915 g/cm³), compressive strength (666–808 MPa), and Vickers microhardness (1.8–2.5 GPa), attesting to their high quality and stability. The results of the hydrolytic stability assessment revealed that the leaching rates of Cs+ and Sr2+ ions from the ceramics are extremely low, within the range of 10−5–10−6 g/cm²·day. These values fully satisfy the requirements of GOST R 50926–96 and the international standard ISO 6961:1982 for solidified forms of high-level waste.

Investigation of the variation of mechanical and durability properties of elements manufactured with rubber substituted SCMs with element height

Controlling the homogeneous distribution of granulated rubber materials added to self-compacting concrete/mortars along the height is of great importance in terms of preserving and defining the holistic behavior of structural elements. In this study, the effect of EPDMGR (ethylene propylene diene monomer granulated rubber) ratio (0 %, 5 %, 10 %, 15 %, 20 % and 25 %), test age, L/D (slenderness ratio) and element test zone (bottom, middle and top) on the mechanical properties (flexural and compressive), durability properties (porosity and sorptivity) of the elements produced with SCM were evaluated. The results obtained were statistically evaluated by GLM-ANOVA. It was observed that flexural tensile strength was strengthened up to 5 % substitution rate due to the hydrophobic properties and elasticity properties of EPDMGR used, while porosity values increased with height in the upper regions compared to the lower regions due to the placement properties of SCM. Differences in compressive strength appeared in the upper and lower sections after 5 % EPDMGR substitution. This indicates that for the mixture properties used, the properties examined in terms of mechanical and durability test results may have different properties with limited variability in terms of L/D ratio depending on the EPDMGR ratio used and the region where the element was taken.

Advancements in Expanded Clay Manufacturing Using "Clay-Desert Sand-Oil Sludge" Sludge Composite Materials

This study explores the development of resource-saving expanded clay technology utilizing underutilized clay raw materials and oil extraction waste. Traditional expanded clay production is energy-intensive and often employs high-quality clay; however, our research identifies technological modes and parameters for producing expanded clay through plastic molding, incorporating substandard raw materials and oil sludge. This method eliminates the need for costly energy-releasing additives and reduces energy costs associated with drying and firing by 25-30%. The research aims to demonstrate the feasibility of this novel production technique in the Republic of Kazakhstan, considering the local availability of raw materials, energy resources, and regional demand for thermal insulation materials in industrial and civil construction. Our findings suggest that integrating 'Desert Sand-Oil Sludge' into the batch composition can effectively produce granulated porous thermal insulation material, aligning with the region's development strategy and offering significant economic and environmental benefits.
 Highlights:
 
 Resource Utilization: Uses oil waste and substandard clay to produce expanded clay, reducing reliance on high-quality materials.
 Energy Savings: Cuts energy costs for production by 25-30% through innovative processing.
 Regional Benefit: Aligns with Kazakhstan's strategy by utilizing local resources and supporting construction needs.
 
 Keywords: Expanded Clay, Oil Sludge, Desert Sand

FTIR spectroscopy analysis assessment of reclaimed asphalt at asphalt mixing plants to optimize the recycling

Reclaimed asphalt pavements (RA) usually are fully recyclable in new asphalt mixtures. The properties of the individually aged and possibly modified bitumen in the RA will affect the mix design of the new asphalt mixture. Furthermore, the RA may contain hazardous PAH-contamination resulting from coal tar, which was applied in German road pavements up to the 1980′s. For identifying substances that impair or influence reusability of the RA the Fourier transform infrared spectroscopy (FTIR) method was modified. Within a total measuring time of approx. 20 min, the binder contained in a sample of granulated road construction material can be recovered by means of a rapid extraction and measured by FTIR-ATR. By evaluating the measured absorption spectra, samples which have to be considered as PAH-contaminated (with PAH contents ≥ 25 mg/kg) could be distinguished from non-contaminated reclaimed asphalt. Furthermore, the presence of styrene-butadiene-styrene (SBS) modification as well as viscosity-changing organic additives could be identified.

Influence of fine aggregate types for the achievement of concrete quality

Fine aggregates in the form of sand are granulated materials, which generally measure between 0.0625 to 2 millimeters. Sand as a fine aggregate mixed with cement and water becomes a concrete mixture that has a role in the strength of construction. This study aims to determine how much influence the fine aggregates or sand of four different mining sites have on the compressive strength of concrete. The method used is an experiment, based on the results of laboratory tests of compressive strength tests at the age of concrete 7, 14 and 28 days for fc’25 or 25 MPa quality concrete with a mix of designs for fine aggregates from Leles sand, Kuyamut sand, Cikamiri sand, and Cilopang sand, Garut Regency West Java Province Indonesia. The aggregates tested include moisture content, sludge content, organic content, dry saturation, waand ter absorption affects the quality of concrete and improves quality strength with the same treatment for laboratory testing. The results of the analysis with 28 days of concrete compressive strength testing obtained the achievement of the highest concrete strength, namely with Cilopang sand 27 MPa, allowed by Kuyamut sand 26 Mpa, Leles sand 25 MPa and Cikamiri sand 23 MPa. Based on the results of concrete strength testing for up to 28 days, there are three sources of fine aggregates that can reach a minimum of fc’ 25, and there is one sand source that has a compressive strength value of concrete.

The mosquito effect: regulatory and effector T cells acquire cytoplasmic material from tumor cells through intercellular transfer.

The phenomenon of intercellular transfer of cellular material, including membranes, cytoplasm, and even organelles, has been observed for decades. The functional impact and molecular mechanisms of such transfer in the immune system remain largely elusive due to the absence of a robust in vivo model. Here, we introduce a new tumor mouse model, where tumor cells express the soluble ultra-bright fluorescent protein ZsGreen, which allows detection and measurement of intercellular transfer of cytoplasm from tumor cells to infiltrating immune cells. We found that in addition to various types of myeloid lineage cells, a large fraction of T regulatory cells and effector CD8 T cells acquire tumor material. Based on the distribution of tumor-derived ZsGreen, the majority of T cells integrate captured cytoplasm into their own, while most myeloid cells store tumor material in granules. Furthermore, scRNA-seq analysis revealed significant alterations in transcriptomes of T cells that acquired tumor cell cytoplasm, suggesting potential impact on T cell function. We identified that the participation of T cells in intercellular transfer requires cell-cell contact and is strictly dependent on the activation status of T lymphocytes. Finally, we propose to name the described phenomenon of intercellular transfer for tumor infiltrating T cells the "mosquito effect".

Evaluation of the effect of granule size of raw tableting materials on critical quality attributes of tablets during the continuous tablet manufacturing process using near-infrared spectroscopy

Objective The effects of granule size of raw materials on tablet hardness (TH) and weight (TW) in the continuous tablet manufacturing process (CTMP) were investigated using near-infrared spectroscopy (NIRS). Methods Granule materials of different sizes were prepared by extrusion granulation from a standard granule formula powder containing lactose/starch and 4.5% acetaminophen. Large-, small-, and medium-sized granules were sequentially filled in a hopper, and tablets were produced continuously using a single-shot tableting machine. After arranging approximately 500 tablets in order, the tablets were subjected to NIRS. A total of 450 NIRS datasets were divided into three groups of 150 each (calibration, validation 1, and validation 2 datasets). Results The best fitted calibration models for predicting TH and TW were obtained, with sufficient accuracy, based on NIRS using the partial least squares regression, and comprised both physical and chemical information. The regression and loading vectors of the calibration models suggested that the models used to predict TH and TW involve physical information based on geometrical factors of the tablet and chemical information related to binder-related intermolecular interactions. Conclusions The changes in the predicted value profiles of TH and TW using NIRS reflected the changes in the measured values depending on the raw granule size during CTMP.

Metaproteomics, metagenomics and 16S rRNA sequencing provide different perspectives on the aerobic granular sludge microbiome

The tremendous progress in sequencing technologies has made DNA sequencing routine for microbiome studies. Additionally, advances in mass spectrometric techniques have extended conventional proteomics into the field of microbial ecology. However, systematic studies that provide a better understanding of the complementary nature of these 'omics' approaches, particularly for complex environments such as wastewater treatment sludge, are urgently needed.Here, we describe a comparative metaomics study on aerobic granular sludge from three different wastewater treatment plants. For this, we employed metaproteomics, whole metagenome, and 16S rRNA amplicon sequencing to study the same granule material with uniform size. We furthermore compare the taxonomic profiles using the Genome Taxonomy Database (GTDB) to enhance the comparability between the different approaches. Though the major taxonomies were consistently identified in the different aerobic granular sludge samples, the taxonomic composition obtained by the different omics techniques varied significantly at the lower taxonomic levels, which impacts the interpretation of the nutrient removal processes. Nevertheless, as demonstrated by metaproteomics, the genera that were consistently identified in all techniques cover the majority of the protein biomass. The established metaomics data and the contig classification pipeline are publicly available, which provides a valuable resource for further studies on metabolic processes in aerobic granular sludge.

Granulated Materials Based on Calcium Silicate Hydrate, Poorly Crystallized Carbonated Hydroxyapatite, and Gelatin

Granulated Materials Based on Calcium Silicate Hydrate, Poorly Crystallized Carbonated Hydroxyapatite, and Gelatin

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System

Effect of TiO2 Additions on the Properties of Bioactive Granulated Materials of the TiO2–SiO2–P2O5/СаO(ZnO) System

Bovine autosomal recessive alpha‐mannosidosis in an Aberdeen Angus herd from Argentina

AbstractAn outbreak of α‐mannosidosis in a bovine herd from Buenos Aires province is reported. Postmortem examination, histology, lectin histochemistry and electron microscopy were performed on five calves born with nervous signs. Hair samples from dams and calves were genetically analysed. The α‐mannosidase gene including exon 7 was amplified and sequenced. At postmortem examination, no gross changes were evident. Histologically, cytoplasmic neuronal vacuolation in the brain and cerebellum of the five calves, staining moderately to intensively, with lectin histochemistry was evident. Ultrastructurally, vacuoles containing finely granulated material in the cytoplasm of neurons, myelin degeneration and axonal swelling were seen in the brain. Genetic analysis revealed a heterozygous carrier state for 961T→C transition in the exon 7 of α‐mannosidosis gene of four cows, and a recessive homozygous state for 961T→C transition in the same genes in the calves analysed. This highlights the importance of identifying and removing animals carrying the α‐mannosidosis mutated gene.

Modification mechanism of flue gas desulfurization gypsum on fly ash and ground granulated blast-furnace slag alkali-activated materials: Promoting green cementitious material

Alkali activation and the combination of fly ash (FA) and ground granulated blast-furnace slag (GGBS) has been used for cementitious material, which is seen as an effective method to dispose of industrial solid waste. The GGBS-FA AAMs have the characteristic of drying shrinkage and a large number of tiny pores distributed in the matrix, resulting in strength deterioration. The paper is aimed to optimize the strength property by incorporating another solid waste of flue gas desulfurization gypsum (DG), which could be regarded as a ternary alkali-activated materials (AAMs). The unconfined compression tests are carried out to study the effects of DG content on strength with different curing times, and the effects from the modulus of the alkali activator are also analyzed. Then X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) are performed to reveal the microscopic mechanism of the effects of DG on the mechanical property. Results show that the incorporation of DG can significantly improve the early strength due to the increase of calcium. The SO42- in DG continuously reacts with Ca2+ and active silicate to form ettringite during the curing period, which can fill micro-pores and tiny cracks to form a denser matrix structure. In addition, the presence of SO42- has the effect of secondary enhanced activation, further promoting the polymerization reaction and enhancing the strength, especially for the low alkaline reaction system. These all contribute to the strength improvement. It should be noted that the DG content must be controlled to prevent the volume-filling effect that leads the AAMs matrix to be loose and porous, and the generation of geopolymer gel would also be impeded in a high-calcium reaction system, further influencing the final strength. The results will promote the application of high-performance, cost-saving, and green low-carbon cementitious material based on the synergistic utilization of GGBS, FA and DG.

Obtaining and study of physical-chemical properties of porous materials based on kaolin

The object of research is kaolin from the Hlukhovetsky deposit (Ukraine). On its basis, granulated sorbent materials were obtained with the addition of various amounts of cellulose as a pore former. After forming the samples, they were dried and fired at a temperature of 800 °C. The obtained granules with a size of 8–9 mm were modified with zero-valent iron. The physicochemical, including sorption properties of granular composites were studied. Using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), the morphology of the obtained samples was investigated and the presence of zero-valent iron particles on the surface and in the pores of the sorbents was confirmed. Based on desorption experiments, it was determined by chemical analysis that the Fe0 content in modified samples with increased pore former content increases from 0.01 g/g of granules for a sample containing 1% cellulose to 0.016 g/g for a carrier with 3 % pore former. The specific surface area and pore volume of the samples were determined by the method of low-temperature adsorption-desorption of nitrogen. Thus, with an increase in the content of the pore former in the ceramic mass, the specific surface of both unmodified and modified samples slightly decreases. Thus, with a cellulose content of 1 %, it is 20 m2/g and 17 m2/g, respectively. When the pore former is increased to 3%, these values are 15 m2/g and 12 m2/g. After applying a layer of zero-valent iron on porous granules, the volume of pores decreases, which is due to the formation of agglomerates of iron particles during synthesis. The study of the sorption capacity of the obtained sorbents with respect to Cr(VI) from model solutions containing a mixture of metal cations (copper, cadmium, cobalt, zinc) showed that granular materials exhibit sorption capacity for metal anions, even in the presence of cations. The amount of chromium sorption naturally increases for modified samples with an increase in the cellulose content in them. However, for model solutions that do not additionally contain metal cations, the sorption value is somewhat higher. Thus, for a sample with a 3 % pore former content, the sorption value is 0.7 mg/g and 0.9 mg/g, respectively, at an initial chromium(VI) concentration of 10 mg/g. The obtained experimental data indicate that the obtained porous granular sorbents based on kaolin can be used in the further treatment of wastewater from electroplating enterprises, which contain a mixture of pollutants in both anionic and cationic forms.

Investigation of Plasma Parameters and Electrical Characteristics of a Barrier Discharge During Plasma Treatment of Granulated Materials

Investigation of Plasma Parameters and Electrical Characteristics of a Barrier Discharge During Plasma Treatment of Granulated Materials

Terahertz time-domain spectroscopy for the investigation of tablets prepared from roller compacted granules

Roller compaction before tableting is a common unit operation to increase the processability of powders. Terahertz time-domain spectroscopy (THz-TDS) has recently been introduced as a potential process analytical technology (PAT) for measuring tablet porosity based on the refractive index of the tablet. Tablet porosity is a governing parameter for tablet disintegration and dissolution. The first aim of this study was to investigate tablets prepared from roller-compacted materials with THz-TDS to explore its usefulness for particle size evaluation of granules in tablets. Secondly, the impact of roller compaction and granule size before tablet compression on the established THz-TDS based measurement of tablet porosity was investigated. Microcrystalline cellulose and α-lactose monohydrate were roller compacted separately at five specific compaction forces (2, 4, 8, 12, and 16 kN cm−1) and fractionated into three size fractions. Tablets were prepared from the fractionated and unfractionated granules at twelve tableting pressures and subjected to THz-TDS transmission measurements. It was possible to use the scattering behaviour of the tablets at terahertz frequencies to describe the granulated materials’ particle size changes during tableting. At the same time, prediction of porosity was impaired due to the deviation of the refractive index in strongly scattering samples. A correction method was introduced in which the porosity error was corrected based on the tablet’s scattering behaviour, resulting in an improved prediction of tablet porosity. In conclusion, THz-TDS is considered a promising technique for the process monitoring of tableting based on its sensitivity to porosity and particle size changes within the tablet non-destructively, with a possible application as part of an in-process control strategy of the tableting of granulated or non-granulated materials.

Experimental design and optimization of a novel solids feeder device in energy efficient pneumatic conveying systems

Pneumatic conveying of powders is an engineering process used for conveying dry granulate or powder material where energy consumption is a significant cost factor and contributes to greenhouse gas emissions. In this RD&I project, work was conducted to model pneumatic conveying and bulk characteristics of the particulate product being conveyed. Because pneumatic conveyance is highly empirical, general models are difficult to establish. Due to these limitations, evaluating energy efficiency is usually limited to a specific experimental range of conditions. This work is based on engineering optimization of a workflow with data from an industrial operation commanded by a Programmable Logic Controller (PLC) with a control algorithm, performing logical, sequential, and timed tasks for plant control. The PLC communicates with a Human–Machine Interface and a Supervision and Control System, which are the means of interaction through a graphical environment interface with the process operator. By applying mathematics to introduce a systematic method to select the gas (air) pressure and flow necessary to operate a pneumatic conveying system in dense phase mode, it has been shown, on an industrial scale of 10 t/h, the feasibility of controlling an efficient pneumatic conveying system manipulating only two input parameters. This allows operation at pre-determined conveying rates with lower operational expenditures. The same methodology can be explored for several other systems.

Strength Characteristics of Geopolymer Synthetic Sand Using Fly Ash

Sand is a naturally available resource that has numerous applications in civil engineering. Due to a rapid increase in construction activities and exploitation of natural resources, there has been a scarcity of natural river sand (NRS), causing environment related issues such as erosion of riverbanks and the lowering of the water table. Hence, there is a need to identify and process sustainable alternative granular materials such as geopolymer synthetic sand (GPSS). In this connection, an attempt has been made for the effective utilization of fly ash in the synthesis of granular materials through geopolymerization. Geopolymer synthetic sand was prepared using 12 M NaOH solution at 100°C for 1 h and the granules produced were used as an alternative for natural river sand. The granulated materials were characterized by their physical properties [specific gravity, water absorption, grain size distribution, specific surface area, and scanning electron microscope (SEM)], chemical properties [pH, electrical conductivity (EC), total dissolved solids (TDS), and cation exchange capacity (CEC)], engineering properties (cohesion, angle of shearing resistance, optimum moisture content and maximum dry density, and hydraulic conductivity), mineralogical properties [X-ray diffraction (XRD)], and thermal properties [thermogravimetric analysis (TGA) and differential thermal analysis (DTA)]. In addition, compressive strength tests were performed on GPSS and NRS mortar. It was noted that GPSS mortar attained similar strength as NRS mortar. Based on the experimental investigations and microanalysis, it can be concluded that GPSS granules have the potential for use as an alternative to natural river sand.