Granulometric Distribution Research Articles

Particle Size as an Indicator of Wheat Flour Quality: A Review

Wheat flour is one of the most important food raw materials, with its quality determined by various indicators. One such indicator is particle size and granulometric distribution. In recent years, numerous studies have focused on the effect of flour and bran particle size on the properties of cereal products such as bread, pasta, noodles, and cookies. The aim of this review was to analyze the extent to which this parameter influences the properties of these cereal products. Additionally, the relationships between flour particle size and its chemical composition were presented. Key factors affecting the granulometric composition of flour, related to wheat grain properties and the grinding process, were also discussed. The study specifically focuses on research conducted in the last five years.

Granulometric and Geochemical Distribution of Arsenic in a Mining Environmental Liability in a Semi-arid Area.

This study focuses on the "El Lavadero" tailings deposit, a mining environmental liability (MEL) located near the town of San Felipe de Jesús, Sonora, in northwest Mexico. The objective was to determine the total arsenic (As) content, its granulometric and geochemical distribution, as well as its mobilization capacity and bioavailability. The results from oxidized and unoxidized tailings showed low potential of hydrogen (pH) values (2.4-5.7) and high concentrations of total arsenic (8235-36,004mgkg-1), predominantly in the finer granulometric fractions (< 0.05mm). Arsenic also prevails in the finest fraction of agricultural soil (> 2mm). These fine particles could present adverse environmental effects due to their potential to be transported by leaching and water suspension. In contrast, arsenic in the effluent sediments is primarily found in the coarser fraction (> 2mm). A significant proportion of arsenic in the tailings (5-40%) was found in the non-residual geochemical fractions (I + II + III) (1106-7675mgkg-1), indicating potential for mobilization and bioavailability. Depending on environmental conditions (redox potential and pH), arsenic can redissolve and exhibit high mobility in abiotic media, which may ultimately impact the environment and human health. Therefore, it is crucial to rehabilitate the "El Lavadero" MEL to prevent further environmental damage. This study provides useful information to understand some phenomena in other global mining environmental liabilities, such as mobilization and bioavailability of arsenic and its possible impact on the surrounding environment and biota, contributing to the worldwide research of ecosystems polluted by mining activity, especially in arid and semi-arid climates.

An application of the DEM-FFT method to predict the thermal conductivity of high burnup fragmented fuel

Understanding Fuel Fragmentation, Relocation and Dispersal (FFRD) phenomena is a major item to predict the behavior of fuel rods in the event of a Pressurized Water Reactor loss-of-coolant hypothetical scenario. In order to introduce an effective medium for fragmented fuel that could be used in fuel performance codes, the heat transfer properties of UO2 granular beds in He-Kr-Xe mixes was studied numerically. The Discrete Element Method was first used to compute the spatial arrangement of powder only submitted to gravity with a representative granulometric distribution. These generated geometries were then transformed into a 3D grid (voxelized) to perform numerical homogenization and compute their effective properties using a Fast Fourier Transform solver for heat transfer. Different hypotheses were made in the voxelation process about how the treatment of gas-solid and solid-solid interfaces, which in turn provided different estimates of the effective properties. Due to limits on the discretization and extended particle size distributions, a two-scale scheme was introduced and numerically tested against direct computations. For several beds, computed thermal conductivities were compared to analytical models for granular materials. Some heat transfer properties of fragmented fuel at several burnups were then computed, taking into account approximations for Knudsen and radiation size effects.

Structural and morphological features of magnetron nanofilms of TaN with different thicknesses

Purpose of research. Study of morphological and phase changes in the structure of tantalum nitride nanofilms formed by magnetron reactive sputtering on a silicon substrate.Methods. Magnetron sputtering on a silicon substrate was performed using the MVU TM-Magna T setup with the sputtering time parameter changing from 300 to 900 sec, and also with constant power parameters of 500 W and working gas pressure of Ar 0,5 Pa. The morphological and phase changes in the structure of tantalum nitride nanofilms were studied using atomic force microscopy and X-ray phase analysis. The fractal dimension was determined using the cube counting method. X-ray diffractometric analysis in the in situ measurement mode with discrete heating (in 100 °C increments) in air up to 1000 °C using the PAAR HTK-16 high-temperature attachment.Results. Using atomic force microscopy methods, it was found that the granulometric distribution of nanoclusters in the studied TaN nanofilms was Gaussian and an increase in the lateral size of particles was observed with an increase in the deposition time. The nanofilm with a deposition time of 300 s had minimal roughness. The statistical fractal dimension was calculated, the value of which corresponded to their three-dimensionality. According to the X-ray phase analysis data, the sizes of the coherence region, texturing, microdeformations and interplanar deformation distortions were determined, and a mixed Stranski-Krastanov mechanism of nanofilm formation was established.Conclusion. The surface roughness of nitride nanofilms formed at a constant power (500 W) depends significantly on the magnetron sputtering time and N2 concentration. In all studied nanofilm structures, the dominant growth mechanism was the mixed Stranski–Krastanov mechanism.

Gas atomization of AA2017 aluminum alloy: Effect of process parameters in the physical properties of powders for additive manufacturing

Close-coupled gas atomization (CCGA) uses pressurized gas jets to atomize molten metals, producing powders suitable for additive manufacturing (AM). Optimization of processing parameters is crucial to achieve powders with good fluidity and high apparent density for laser powder bed fusion (L-PBF) and increase production yield. This study evaluated the influence of melt feed nozzle diameter, superheating temperature, and atomization pressure on AA2017 aluminum alloy powders' physical properties. Parameters variation poorly affected the median particle diameter (d50), while significantly altering the particle size distribution curves width (IDR = d90-d10). Suitable powders for AM/L-PBF were produced using a specific set of parameters (d0= 1.5 mm; ΔT= 150 °C; PG= 20 Bar), presenting appropriate fluidity and apparent density due to an optimal granulometric distribution and morphological characteristics. Mathematical analysis showed a good correlation between experimental and calculated mean particle size, suggesting an equation to predict percentile d90 based on previous correlations.

Исследование гранулометрического состава измельченного продукта, полученого при измельчении доломита в центробежной мельнице вертикального типа

Introduction. Modern medium (10–200 microns) and fine (0.1–10.0 microns) powders have a high cost, which limits the scale of their production and use. This assumes the implementation the latest achievements in the field of creating new equipment that is not inferior in its technical characteristics to the best foreign models into industry. The use centrifugal mills of vertical type for grinding various raw materials has shown their high efficiency in obtaining materials in the range – 0.2–0.01 mm. Studies of these mills operation under various operating conditions made it possible to create a large data set on the dependence of the crushed material granulo-metric composition on the design features of the mills and technological parameters of the grinding process. The results of a previously study of the granulo-metric composition a finely dispersed crushed product integral distribution according to particle size classes less than 80 microns were presented. They were obtained in a Brookhaven BI-XDC X-ray analytical centrifuge by measuring particle sizes in natural sedimentation mode, when the centrifuge disk was stationary during the experiment. The studies of the particle size differential distribution of a finely dispersed crushed product according to particle size classes less than 80 microns, which have not been carried out to date are of particular interest. Purpose of the study. The differential distribution study of the finely dispersed granulo-metric product composition obtained by grinding lump dolomite in a centrifugal mills of vertical type under different operating modes. Materials and methods. To solve this problem, samples of crushed material were taken from grinding dolomite from the Bosninsky deposit (RNO-Alania) in a centrifugal mill of the vertical type MV-0.3 with a 300 mm rotor diameter with following technological modes of the grinding process: mill rotor speed n = 310; 360 min–1, height of the material column above the rotating rotor H = 180; 270 mm, test time – 6 hours. Selected samples with a size class of –0.08 mm were analyzed in an X-ray analytical centrifuge Brookhaven BI-XDC, designed to determine the particle size distribution in the range from 0.01 to 100 microns. The measurements were performed on a suspension prepared from a mixture of 0.5 g of the selected sample with a 20% solution of sucrose and distilled water. Samples with a size class of 0.08 mm were weighed on laboratory scales LV SP.005.048 RE. The resulting suspension was dispersed in an ultrasonic bath for 3–5 minutes. After dispersion, the suspension was poured into the analyzer disk. While stirring, the lower absorption baseline line of a homogeneous particle suspension was measured. The obtained data from the analysis of the fine fractions size of were processed by the centrifuge computer software and graphs of the differential distribution of particles were constructed for various technological modes of grinding dolomite in a centrifugal mill. During the processing of the experiments, minor bursts in the concentration of the crushed product were not taken into account. The results and discussion. For the first time, a differential analysis of the granulo-metric composition of finely dispersed material with a particle size of –0.08 mm, obtained by grinding lump dolomite in a centrifugal mill of the vertical type under different mill operating modes, was carried out. Under all investigated operating modes of the centrifugal mill, the main part of the fine fraction in the mill outlet was in the range from 1.197 to 4.643 μm, and in steady-state operation it varied from 1.310 to 4.601 μm. The range of fine particle sizes has maximum values when the height of the column of crushed material above the rotating mill rotor and the rotation speed of the mill rotor decrease, and minimum values are observed when the height of the column of crushed material above the rotating mill rotor increases and the rotation speed of the mill rotor increases. Resume. 1. The article presents the results of the granulo-metric composition differential distribution study of a finely dispersed product obtained by grinding lump dolomite in a centrifugal mill of the vertical type. 2. The conducted studies have shown that, despite the positive results in obtaining fine particles with a size of 0.001 microns (nanoparticles) by mechanical means, the industrial production of nano-materials when grinding lump mineral raw materials in a vertical centrifugal mill is not economically profitable due to the low specific productivity and high energy intensity of the grinding process. 3. The obtained research results can be useful in the design of centrifugal mills.

CARBON STOCK, RATES OF CARBON ACCUMULATION AND DISTRIBUTION OF PARTICLES IN A LAKE OF THE ANAVILHANAS ARCHIPELAGO, NEGRO RIVER - AMAZON DURING THE LAST 1900 YEARS

Recent studies show that, despite great variability, the lake systems of the Amazon Basin have presented significant results in the accumulation and storage of organic carbon (TOC). However, the demonstration in the region is still limited and lacks more data to better estimate this non-carbon component of the region. The objective of this article was to estimate the carbon stock, the carbon accumulation rates and characterize the granulometric distribution of an Amazonian lake located in the Anavilhanas Archipelago, in the Lower Negro River region. Data were carried out using the 14C method and analyses of density, granulometry and TOC rate sof samples of a sediment core 1 meter deep. The results have shown that, during the period of 1900 cal years BP, Lake Boto presented two isolated peaks of sand particle sedimentation possibly related to major hydrodynamic events. Generally, well-defined characteristics of a lacustrine environment with sedimentation of fine silt and clay particles predominate. The sedimentation rate was 0.03 cm.year-¹ between approximately 1900 to 850 cal years BP and 0.07 cm.year-¹ in the last 850 cal years BP. It is estimated that Lake Boto has a stock of approximately 231,000 tons of TOC accumulated during the entire period. The stock of TOC is not significant as it is estimated for the soils of the Amazon. The results are an important indication of the role of the Anavilhanas Archipelago as a TOC sink.

Sustainable Mining: Reuse of Clay from Abandoned Areas in the South of Brazil for Ceramic Production Based on a Simplex Design.

The environmental impact of clay mining can be minimized using extractive mineral circularity practices. Combining the available knowledge of the characteristics of different clays with statistical tools was a decisive step for the improved use of mining resources. Through blends, all the mined materials can be incorporated to produce quality ceramic products. This study identified two types of clay from abandoned mining areas in the southern state of Santa Catarina, Brazil. These raw materials were valued together with plastic clay, which is widely used in the region, to develop 10 different formulations using a mixture design method. The clays were characterized using average granulometric distribution, mineralogical composition, and chemical, thermal and plasticity analyses. The specimens were shaped by extrusion, dried in an oven, fired in a muffle furnace and characterized based on their shrinkage, water absorption and compressive strength values. Two clays with varying characteristics-one with low workability and the other with a high silica content-exhibited difficulties (generating defects) in the extrusion shaping process, which compromised the final quality of the ceramic paste. Results showed that incorporating up to 45% by mass of the low-workability clay resulted in an increase in water absorption. The more siliceous clay improved dimensional control; however, its use at high contents (~80%) decreased the mechanical resistance. Nevertheless, when used in controlled amounts, these clays can be beneficial to the production of blocks and bricks because they have the potential to improve some properties of the finished ceramic products.

Ballast with siderurgic aggregates: variation analysis of the shape parameters of particles submitted to triaxial tests through 3D scanner

Across countries, associations and institutions publish technical standards for railway ballast, however it is observed that those norms have differences when compared to each other. Each one of them has its particularity, varying according to the stone materials available in their countries, axle load and climate. In that sense, it is still a challenge to establish specific guidelines for the properties of the ballast layer. Recently, several techniques for acquisition, image analysis and particle scanning have been developed, either in 2D or in 3D. Those techniques vary from the use of pachymeter to the use of sophisticated scanners. This research seeks to evaluate, through laboratory tests, the evolution of the particle shape parameters through 3D scanning and the level of degradation of the steel slag when subjected to stresses close to those experienced in freight transport railways. Based on the performed tests and the obtained results, the authors recommend for a railway pavement subjected to a load of 32.5 t/axle and composed of steel aggregates used as ballast, a granulometric distribution with uniformity coefficient 1.5 ≤ Cu ≤ 1.6 (AREMA n. 4) and particles with: 0.625 ≤ Elongation ≤ 0.999, 0.567 ≤ Flatness ≤ 0.995, 0.475 ≤ Aspect ≤ 0.969 and 0.825 ≤ Ellipsoidness ≤ 0.957. These specifications enable a good performance of the ballast layer. In addition, the results found contribute to the understanding of siderurgic aggregate behavior under cyclic loading conditions.

Microabrasive wear behavior of different stellites obtained by laser cladding and casting processes

Cobalt superalloys are used in several applications, mainly involving corrosive environments and high temperatures, in which wear and corrosion resistance are key factors in their performance. These alloys can be produced by a variety of manufacturing processes. Among these, the technology of laser cladding coatings has emerged as a promising and economically viable alternative to produce coatings from cobalt-based alloys. One of the applications of these alloys is in the production of components to obtain second-generation ethanol. In this application, about 8% of the processed material is composed of micrometric abrasive particles, mainly silica, among others, which cause wear of components. In order to better understand the tribological behavior of these alloys in microabrasion, three coatings of commercial cobalt-based superalloys, Stellite 1, 6 and 12, were produced by laser cladding. Additionally, two cast alloys, Stellite 250 and an experimental Stellite alloy, were also evaluated. Microabrasion tests using a statistical design of experiments were performed with SiO2, Al2O3 and SiC abrasives in a suspension of distilled water. Statistical analysis revealed that the wear coefficients of these alloys are influenced by both the abrasives and the alloy. The as-cast Stellite 250 alloy showed the highest wear coefficients, while the coated Stellite 1 and the as-cast experimental Stellite showed the lowest wear coefficients. The predominant wear micromechanism was scratching, except for Stellite 6 and 12 coated alloys in SiC tests, in which predominant mechanism were mixed and rolling, respectively. The presence of secondary micromechanism of rolling wear was also observed and associated with the granulometric distribution of the abrasives. The analysis of wear severity allowed the comprehension of the granulometric distribution influence of abrasive particles on wear.

Effect of Aggregates Packing with the Maximum Density Methodology in Pervious Concrete

The granulometric distribution of the aggregates used in pervious concrete can significantly impact its mechanical and hydraulic properties by modifying granular skeleton and pore distribution. The unit weight increases when single-sized aggregates are combined, which results in improved mechanical properties. In this study, the maximum density methodology was applied to enhance pervious concrete’s mechanical strength by using three narrow-sized basaltic aggregates and their combination. The experimental results showed that the mechanical performance of the samples created with packed aggregates improved compressive strength by up to 81.2% and the energy support impact was higher than 225 J (50% higher than the reference sample) after curing for 28 days. Although the densification of packing aggregates increased, the greatest reduction in porosity was 24.3%. The lowest infiltration rate was 0.43 cm/s, a satisfactory value according to the literature. These findings suggest that the aggregates packing methodology is effective in producing optimized and sustainable pervious concretes.

Addition of sodium alginate capsules containing Lysinibacillus sphaericus for self-healing of cracks in mortars

The biomineralization technique of crack remediation in construction mortar can be achieved through the incorporation of calcifying bacteria within the mortar matrix. However, the thermal and autogenous shrinkage associated with the hydration of cement can be detrimental to the survival of the bacterial spores. Encapsulation of the spores in a matrix such as superabsorbent hydrogels, specifically sodium alginate, can provide protection from such detrimental conditions while also serving as a water reservoir for the metabolic activity of the bacterial cells. This paper investigated the addition of sodium alginate capsules prepared through spherification in construction mortars, aiming to preserve and optimize rheological, physical and mechanical properties, and to release bacteria when cracks occur. Mortar formulations with capsules containing Lysinibacillus sphaericus were calculated in order to maintain the granulometric distribution of standard formulation, thus obtaining products with excellent rheological, physical and mechanical properties, and allowing the addition of up to 1% capsules. Multivariate analysis of variance was applied at each age, showing that formulations with capsules kept the same properties as the original formula. After cracking, it was possible to observe the action of the released bacteria, through the formation of crystalline structures at the cracks. The capsules were prepared through a simple and cheap process, and it was proved that not only they do not affect concrete properties, but also are effective in both protecting the bacteria during mixing and hardening and releasing it after cracking.

Magnetic Separation and Enrichment of Fe–Ti Oxides from Iron Titaniferous Beach Sands: Process Design Applied to Coastal Ecuador

Iron titaniferous sands, also called black sands, are a source of various magnetic minerals, such as iron and titanium (Fe–Ti) oxides, with countless scientific and industrial applications. Ecuador is deemed a geo-diverse country that contains deposits of black sands in the Andean and coastal regions; therefore, the industrialization of these magnetic sands might be of high interest. This study presents a preliminary industrial design for the magnetic separation process of Fe–Ti oxides from iron titaniferous Ecuadorian beach sands. Four stages are considered for the process, involving collecting, drying, screening, and magnetic separation. This proposal returns the large particles (&gt;150 μm) and the non-magnetic fraction to the original place, generating a minimum environmental impact with the support of natural marine and coastal processes. The process design criteria are based on engineering guidelines, sampling, and characterization of eleven black sand samples. Using conventional techniques, the water content, granulometric distribution, particle size, and semi-quantitative Fe–Ti oxide concentration were determined for the different sand samples. It is estimated that Fe–Ti oxide production may reach 5.835 metric tons per day (5.835 mtpd) with a magnetic content of 97.50%, starting from 100 mtpd of black sands. Based on an economic analysis (Class V), a net profit of USD 835,875.63 is expected during the first year of production. Thus, the magnetic separation and enrichment of Fe–Ti oxides from iron titaniferous coastal sands exploitation should allow the commercial valorization of these resources in an eco-friendly way, i.e., with economic benefits and minimization of environmental impact in the source area.

Comparative study of pre-Hispanic and colonial adobes in Mexico. Preliminary inferences on the effects of the granulometric distribution and used recycled materials in the state conservation of earth architecture

The characterization of the pre-Hispanic and colonial adobes used in the construction of buildings in Mexico was carried out to know the differences between their processes and manufactures. The eight samples obtained correspond to adobe blocks 0.45 m long x 0.35 m wide and 0.12 m thick, which were part of the interiors of houses, the structure of fences, and hacienda galleys. These samples were investigated using X-ray Diffraction, X-ray Fluorescence, and Scanning Electron Microscopy techniques to determine the morphometry of the material and its chemical and mineralogical composition. Likewise, some analyzes were performed to determine their mechanical properties (simple compressive strength), physical properties (granulometry, solid density, cohesion, plasticity index, porosity, and moisture content), and biological (organic matter content). The results obtained in terms of the granulometric distribution indicate that pre-Hispanic adobe has a higher content of sand than silt-clay and gravel, while the colonial adobes present a low or null content of gravel with a higher content of silt-clays. Regarding the organic matter content, the colonial adobe presents the highest percentages compared to those of the pre-Hispanic adobes. Taking into account the above the pre-Hispanic adobes have better resistance and durability than colonial adobes due to their granulometric distribution, low organic matter content, good cohesion, high plasticity index, and the use of materials found in their natural environment, while the colonial used recycled materials, coming from the economic activity to which the hacienda was dedicated, for example, agriculture, mining, livestock, this has given rise to different manufacturing techniques and construction styles that reflect the state of conservation of buildings throughout the pre-Hispanic and colonial times. The granulometric distribution that pre-Hispanic adobe provides favorable physical and mechanical qualities for any construction technique, so it is recommended to use this formula to manufacture resistant and durable adobe.

Sintering resistant CO2 sorbents prepared by eggshell derived xerogels

• Sustainable and stable CO 2 sorbents were prepared from eggshells. • Lime sorbents were prepared by combustion of carboxylic acid derived xerogels. • Release of gas & heat during xerogel combustion modifies sorbents’ morphology. • Sorbents’ unimodal granulometric distribution minimizes particles coalescence. • Eco-friendly lactic acid sorbent showed the slowest carrying capacity decay. A sol–gel like method was used to prepare CaO sorbents from eggshells, and carboxylic acids, with improved sintering resistance. Sorbent materials obtained by calcination (900 °C) of the calcium xerogels presented different morphologies depending on the acid used as the complexing agent (citric, lactic, oxalic, maleic, acetic, and propionic). Sorbents were tested for cyclic carbonation (700 °C, 15% CO 2 in N 2 )/decarbonation (800 °C, in N 2 ) in a thermobalance. Sorbents had distinct specific areas and porosities resulting from the release of gaseous molecules, and heat, from the thermal decomposition of xerogels. The particle size distribution of sorbents was also a function of the acid. The acid carbon chain and the combustion enthalpy have opposite effects on the morphology of sorbents. The lactic acid-derived sorbent was the most performant showing the lowest carrying capacity decay. After 50 cycles the loss of CO 2 capture capacity was 45% for the lactic acid-modified sorbent, while the unmodified sorbent showed a sorption capacity decay of 74%. Scanning electron microscopy showed, after cyclic carbonation/decarbonation, a sintered morphology for the sorbent derived from raw eggshells. This sorbent presented non-porous large aggregates, while the lactic acid-derived sorbent showed a clear network of voids within the crystals agglomerates and a coral-like morphology that is known to confer sorbent stability. This sorbent was the only sorbent with a particle size distribution closer to the unimodal, while the other samples were bimodal. The absence of smaller particles reduces the contact between sorbent grain boundaries at high temperatures, which minimizes the sintering process.

Enrichment of Metals in the Sediments of an Industrially Impacted Estuary: Geochemistry, Dispersion and Environmental Considerations

The city of Avilés is one of the most industrialized cities in the north of Spain and, accordingly, its estuary and coastal area have been subjected to great anthropic impacts in the last 100 years. This research attempts to establish a preliminary scenario of the geochemical and environmental status of both coastal and estuarine sediments in this area. For this study, a total of 96 sediment samples were collected, processed and analyzed to quantify the granulometric distribution of the sediments, as well as their concentrations of organic carbon and main metal(oids) that may cause an environmental risk. The results show that the estuarine sediments present important concentrations of Cd, Hg, Pb and Zn that allow them to be clearly differentiated from the coastal sediments; this information, along with the sedimentology, implies that the estuary acts as a sink of pollution and not as source to the coastal area. Inside the estuary, the high levels of contamination produce a significant potential ecological risk due to contaminant transfers to other environmental compartments and to the biota. Although direct discharges of industrial effluents have been gradually eliminated, the current state of the sediment requires the implementation of measures that are more consistent than natural regeneration in order to ensure low risk levels for the ecosystem.

Silica extraction from rice hull ash through the sol-gel process under ultrasound.

Rice is among the main foods produced in the world and is part of the daily diet of most families. The main waste from rice processing is rice husk (RH), which has been used as biomass for energy generation through combustion. In this process, rice husk ash (RHA) is generated as a residue, and its silica (SiO2) content varies from 85 to 98%. The present work describes the study of the extraction of silica from RHA by the ultrasound-assisted sol-gel method. An experimental design based on the response surface methodology (RSM) with the symmetrical, second-order rotational central composite design (RCCD) was applied to determine the best extraction conditions considering extraction time and molar ratio (n) as variables = nNaOH/nSilica). These optimal conditions were then applied to three ash samples, two obtained by the combustion process in a boiler furnace, with a mobile grate system (RHAC1 and RHAC2), and one obtained by the pyrolysis process (RHAP) carried out in a fixed bed reactor. Results showed that a molar ratio of 4.4, and an extraction time of 107min were the best extraction conditions, leading to a yield of 73.3% for RHAP, 43.9% for RHAC1, and 31.1% for RHAC2. It was found that the extraction yield and textural properties of the silica obtained depend on the characteristics of the ash used. The silica extracted from RHAC1 presented a surface area of 465 m2.g-1, mesopores of 4.69nm, purity greater than 95%, and an ultra-fine granulometric distribution, reaching nanoparticle dimensions, characteristics comparable to commercially available silicas.

Facies, Geochemistry, and Ceramic Properties of Corumbataí Formation, Upper Permian of Paraná Basin, and its Application in the Ceramic Industry, Brazil

AbstractThe supply of Corumbataí Formation rocks, which occur widely in the State of São Paulo, Brazil, and are used by Santa Gertrudes Ceramic Cluster, is dwindling and prospecting for new deposits is essential. The current study aimed to map and characterize new reserves of ceramic raw materials which would guarantee mineral and economic sustainability of the important concentration of ceramic-processing capability in that area, and thereby contribute to improving and diversifying the range of products manufactured and to promoting a greater presence in the international market. To achieve the proposed objectives, 16 profiles were sampled and the samples were submitted to granulometric analysis by laser diffraction, and the major elements by inductively coupled plasma-mass spectrometry, and the mineralogical compositions of clay samples were determined by X-ray diffraction and ceramic properties. Six lithofacies were identified and grouped into two facies associations: a lower shoreface association comprising massive siltstone (Sm) and laminated siltstone (Sl); lithofacies, and an upper shoreface association comprising heterolithic sandstone (Sh), lenticular sandstone (Sle), intercalated sandstone/siltstone (Si), and altered siltstone (Sa) lithofacies. The lithofacies of the lower shoreface association were more clayey, flux with a significant presence of illite and microcline, and a more uniform granulometry distribution, which made its classification possible, technologically, as stoneware and semi stoneware. The main application of this material is in the production of coatings through the wet milling process. The lithofacies of the upper shoreface association was sandier, had a refractory presence with kaolinite and montmorillonite, and had a less uniform granulometric distribution; technologically, it can be characterized as porous and semi-porous. The main application of this material is in the production of coatings by the dry milling process. The results obtained by facies analysis combined with the geochemical and ceramic properties of the Corumbataí Formation rocks revealed both vertical and lateral variations of the lithofacies, which influence their properties, behavior, and application as ceramic raw materials.

Quality of Oil Pressed from Hemp Seed Varieties: 'Earlina 8FC', 'Secuieni Jubileu' and 'Finola'.

In the last decade, the demand for edible niche oils has increased. Therefore, the aim of this study was to characterize the seeds hemp (Cannabis sativa L.) varieties: ‘Finola’ (FIN-314)’, ‘Earlina 8FC’, and ‘Secuieni Jubileu’, and cold and hot pressed oils were prepared from each seed. The seeds were examined for moisture content, granulometric distribution, bulk density, and fat content. Seeds were pressed without and with preconditioning (60 °C), and oil yield and pressing time were recorded. The oil was filtered through cellulose membranes. Oil–water content, oil color, fatty acid profile, and sterol content were studied. From the study conducted, there are significant differences in the parameters of oil recovery and its quality compared to ‘Finola’ seed oil, which is widely reported in the literature. ‘Finola’ oil yield was the lowest, with an average of 79% compared to ‘Earlina’ (82%) and ‘S. Jubileu’ (84%). All oil samples contained a comparable amount of sterols, with campesterol (0.32 mg/g), β-sitosterol (1.3 mg/g) and Δ5-avenasterol (0.15 mg/g) predominating. From the organoleptic evaluation, it was evident that both varieties hemp oils and marc (‘Earlina’ and ‘S. Jubileu’) were not bitter like the “Finola” oil and marc. More detailed studies in this direction have to be undertaken.

Environmental Magnetism, Geochemical and Textural Characteristics of the Sediments of Beypore Estuary, Northern Kerala, India : Implication on Environmental Processes

The inter-relationship between the environmental magnetic parameters, geochemical and granulometric distribution are addressed in this paper to assess the environmental conditions employing the surficial sediments of Beypore Estuary, Kerala. The magnetic results elucidate the dominance of magnetic grain size in the lower estuary, magnetic concentration in the middle, and magnetic mineral in the upper estuary, respectively. The magnetic parameters confirm the presence of ferrimagnetic minerals such as magnetite in the estuary. The geochemical elements affinity attribute towards the lower estuary. Further, intense weathering in the lower estuary and moderate to weak weathering in the middle and upper estuary are observed which is reflected in the micro-texture features of quartz grains. The Beypore sediments are moderately polluted based on the pollution indices. The finding elucidates the combination of natural and anthropogenic activities, controlling the environmental conditions in the estuary.