Sand Size Research Articles

Evaluation of Changes in Particle Size and Production of Sand and Cake Produced in Wet Aggregate Production Process

Evaluation of Changes in Particle Size and Production of Sand and Cake Produced in Wet Aggregate Production Process

Filling performance of self-protecting underwater mortar via aggregate interstices in the water environment

Although numerous studies have explored the performance of mortar with aggregates, research into the principles governing the filling of mortar in aggregate interstices in water environments, as well as strategies for effective filling, remains limited. This study investigates the effects of several factors on the filling of aggregate interstices by mortar, including the pouring environment, aggregate size, flowability, and maximum particle size of sand. Additionally, it examines the relationship between concrete porosity and strength at both the macroscopic and microscopic levels across different environments, namely air and water. The findings indicate that a reduction in the aperture ratio (Dr) increases the likelihood of granular blocking, thereby reducing the efficiency of mortar filling. Moreover, compared to the air environment, in the water environment, the reduction in pressure differential slightly decreases the mortar filling capability, which in turn leads to a higher porosity in the concrete, manifesting as lower compressive strength of the concrete. Furthermore, a formula has been derived to accurately forecast the outcomes of mortar filling within aggregate interstices.

The use of Iron Sand as Filtration Media for Slaughterhouse Wastewater Treatment

An increase in slaughtering animals will have an impact on increasing the liquid waste produced. The resulting RPH liquid waste can damage the environment if it is not treated, so it is necessary to conduct research to reduce pollutant levels so that it is suitable for disposal into the environment. The technique used in processing RPH wastewater is iron sand filtration method. Iron sand filtration is a filtering process using renewable media, namely iron sand. Iron sand is known to contain the mineral magnetite (Fe3O4) which has the ability to absorb colloidal solids, so it has the potential to be used to remove pollutant content of RPH liquid waste. This research objective to determine the effect of variations in the thickness of the filtration media (cm) and grain size (mesh) on pollutant parameters. The thickness variations used were 20, 25, and 30 cm, with grain sizes of iron sand 40, 60 and 100 mesh. The experimental results showed that the iron sand filtration method was able to reduce Chemical Oxygen Demand (COD) and Total Suspended Solid (TSS) levels, increase the Dissolve Oxygen Meter (DO) value, and change the pH value. The highest reduction in COD was in the thickness variation of 30 cm with 100 mesh. the percentage of decrease in the value of Chemical Oxygen Demand (COD) was 95.05%, the highest decrease in Total Suspended Solid (TSS) value was in the media thickness variation of 30 cm with 100 mesh, the percentage of TSS value reduction was 97.11%, the pH value increased in the thickness variation media 30 cm with a mesh number of 100 from 5.8 to 7.4, and the value of Dissolve Oxygen Meter (DO) increased with variations in thickness of 30 cm with 100 mesh, increased from 1.2 to 15.2. Based on the parameter test results, it was concluded that iron sand filtration is effective in reducing pollutant levels below the quality standard, so that it is expected to be applied directly on a larger scale.

Variations in Composition and Size of Red Sand in Pinang City, North Sumatra to Improve Concrete Quality

This study further explores the problems in the concrete material studied in terms of variations in the structure of the constituent materials and the grain size of red sand on the compressive strength test of quality concrete material with code K-350. The primary raw material uses red sand with compositions ranging from 0%, 2%, 4%, and 6% with sizes ranging from 120, 100, and 80 mesh. After all the ingredients are mixed, printing is carried out according to the predetermined sample size; after the sample is deposited for one day and one night, the sample is opened from the mold mall. To see the quality of the sample, testing was carried out by testing the concrete structure through the SEM test, and the sample elements were looked at by testing XRD, compressive strength, and water absorption. The results obtained were a successive decrease in water absorption in red sand samples with a composition of 4%. In addition, the maximum compressive strength value was obtained at the proportion of 120 mesh material, and 6 percent of the material composition obtained a compressive strength value of 35.27 MPa. When viewed from the size of the concrete structure using the scanning Electron Microscope test, it was found that the size of the red sand mixture concrete structure has a much smaller pore structure when compared to other mixtures. and in the X-Ray Diffraction test, it was found to contain elements in the form of SiO2, CaO3, Ca (OH)2 with the highest intensity of silicon.

Pore Water Conversion Characteristics during Methane Hydrate Formation: Insights from Low-Field Nuclear Magnetic Resonance (NMR) Measurements

Understanding the conversion characteristics of pore water is crucial for investigating the mechanism of hydrate accumulation; however, research in this area remains limited. This study conducted methane hydrate formation experiments in unconsolidated sands using an in-house low-field nuclear magnetic resonance (NMR) system. It focused on pore water conversion characteristics and influencing factors such as initial water saturation and sand particle sizes. Results show that methane hydrate formation enhances the homogeneity of the effective pore structure within sand samples. The conversion rate of pore water is significantly influenced by differences in heat and mass transfer capacity, decreasing as initial water saturation and sand size increase. Pore water cannot be fully converted into hydrates in unconsolidated sands. The final conversion ratio of pore water in water-poor sand samples nears 97%, while in water-rich sand samples, it is only 65.80%. Sand particle size variation has a negligible impact on the final conversion ratio of pore water, with ratios exceeding 94% across different particle sizes, differing by less than 3%.

Upscaling active rheology control to cement mortar with the intervention of an inline magnetic field

Upscaling the printing ink from cement paste to mortar level is the path people must take to apply active rheology control to smart and advanced digital fabrication, which will decrease the content of binder and reduce carbon footprint. This study investigates the rheological response of cement mortars with carbonyl iron particles (CIPs) by using penetration tests and vane tests. A customized magnetorheological test setup, making use of a pipe/nozzle-like inline magnetic intervention, was developed to modify the rheological properties of responsive mortars within a few seconds. The alignment of magneto-responsive particles and the hindrance of sand on magneto-responsive particles in the mortars were visualized and determined by scanning electron microscopy (SEM). With an inline magnetic field, the yield stress determined by the slow penetration test and the torque measured by the vane test increased by a significant factor. The magneto-responsive effect and the response speed rate of the mortar can be adjusted on demand and in time. The effect of cement-to-sand (c/s) ratios and sand gradations on the magnetorheological response of cement mortars was studied. With the increase of sand content (decrease of c/s ratio), the percent increase of yield stress and torque decreased and the magneto-response speed reduced, which indicates a reduction in response efficiency. The magneto-responsive particles could more easily move in the mortar when the particle size of sand increased. Experimental proofs of concept to apply active rheology control to a 3D printing nozzle or pumping line were conducted.

Magnesium Addition and Treatment of Reinforcement Particles in Al6061 – Sea Sand Composite on Coefficients Friction and Wear Rate

Aluminium matrix composite is a composite material that can be used as reinforcement to increase the tribological properties of composite. The process of manufacturing the Al6061-Sea sand composite used the stir casting method with stirring time of 10 minutes and speed of 600 rpm. Stir casting specimens were manufactured with height dimension of 20 mm and diameter of 10 mm. After that, the specimen was friction tested using the pin on disc method. The highest coefficient of friction was the specimen without electroless coating with the addition of 2 wt% Mg of 0.634. The more mass fraction of sea sand, the higher the porosity, and the lower the density. An electroless coating process can be carried out on reinforcing particles. This study aims to determine the effect of addition of Mg and treatment of reinforcing particles on the Al6061-Sea sand composite on the coefficient of friction and wear rate. The coefficient of friction, the specimen density increased, the porosity and the wear rate, decreased. This occurred because the reinforcement particle size of sea sand bonded strongly to aluminium matrix. The highest coefficient of friction was the electroless coating with the addition of 2 wt% Mg of sea sand, which was 0.646.

Physico-chemical alteration of pyroxene in coastal environments: Empirical constraints from New Zealand and the Azores

Developing approaches to determine the modes of transport and weathering of mafic detrital minerals in natural sedimentary environments is critical to our understanding of sediment production, dispersal and provenance, as well as carbon capture under natural and enhanced weathering regimes. We integrated the characterisation of morphological and surface textures with the surface composition of recent detrital clinopyroxene grains concentrated in a sandy coastal area from the western North Island of New Zealand and a rocky shore area of Santa Maria Island in the Azores Archipelago. Using the compactness shape descriptor, 341 grains were subdivided into elongated, elongated angular, euhedral, angular and subangular groups, with each group further characterised using morphological and microtextural indicators of abrasion, breakage and dissolution/chemical weathering. In both studied environments, the clinopyroxenes are dominated by elongated to angular shapes with flat cleavage surfaces and conchoidal fractures. This is consistent with dominant subaqueous transport by rivers and longshore currents for New Zealand, and dominant wave action with limited sediment supply by rivers along the rocky shore of Santa Maria. More abundant subabraded and abraded shapes with bulbous and elongated depression microtextures are observed in New Zealand, which indicates additional effects by aeolian transport that are not seen in Santa Maria. Consistent with semi-quantitative EDS spot analyses that document fresh clinopyroxenes surfaces, chemical weathering textures are very rare to absent. In Santa Maria, sampling of recent beach sand was complemented by ∼125 kyr-old palaeobeach clinopyroxenes, but these yielded similar textural results without evidence for chemical weathering. However, the surface of these older clinopyroxenes includes small adhering smectite (typically <50 μm in width and a few μm in thickness) interpreted to reflect incipient cementation with buffering of acidic fluids by more reactive lithic fragments in the deposits. The lack of chemical weathering but pervasive evidence for mechanical breakage of clinopyroxenes indicate that, at the sand size, these minerals break faster than they dissolve due to frequent subaqueous and/or aeolian reworking in the studied high-energy environments and temperate climatic conditions.

Prediction of Bedform Dimensions on Alluvial Bed in Unidirectional Flow

In this study, the bedform dimensions of an alluvial bed in a unidirectional flow were experimentally investigated. A series of flume experiments was conducted; 700 sets of flume and field data were used in developing formulae for predicting the bedform dimensions on alluvial beds in unidirectional flow. Bedform dimensions include the length and height of bedforms generated by the lower and upper flow regimes; the resistance coefficient for the flow in different flow regimes is introduced into the proposed formulae. The momentum boundary-layer thickness was introduced as an independent variable instead of the flow depth. Based on a large amount of flume and field data, the coefficients of each parameter were determined; four typical formulae were used to compare the accuracy of the proposed formulae. The experimental results show that the momentum boundary-layer thickness, hydraulic radius, and resistance coefficient for the flow in different regimes correlate well with the bedform dimensions. The calculation results show that the dimensionless particle size should not be ignored in the calculation of bedform dimensions. The bedform dimensions have an obvious trend of rapid increase with an increase in the ratio of flow depth to sand size (H/d). The bedform dimensions obtained using the van Rijn method and the Engelund and Hansen method did not represent the variation trend of the bedform length in the upper flow regime with an increase in H/d when H/d was greater than 103. The calculations using the proposed formulae are more accurate and reasonable than those in previous studies predicting the bedform height and length on an alluvial bed in a unidirectional flow.

Performance of Rapid Sand Filter Dual Media for Microplastic Removal in the Water: The Effect of Microplastic Size and Effective Size of Filter Media

Microplastics (MPs) significantly damage the environment and human health, leading to a growing global concern. MPs have been detected not only in the natural environment but also in the drinking water treatment process. One of the configurations of the drinking water treatment unit is filtration. Only a few research studies have been published on microplastic removal in the water system. This study was conducted to determine the performance of a rapid sand filter (RSF) in removing microplastics in water with a variation in the effective size (ES) of silica sand and microplastic size. In this study, microplastics are artificially made with size variations of &lt; 400 μm and &gt;400 μm. The filtering uses two variations in the adequate size (ES) of silica sand, namely 0.4 mm and 0.7 mm. At the same time, anthracite is only a control variable with ES = 0.69 with a flow speed of 4 m / h and an observation time of 30, 60, 90, and 120 minutes. The results show that the filter media ES 0.4 has the highest efficiency values of 91.30% for the microplastic size MPs &lt;400 µm and 95.80 % for the larger microplastic &gt;400 µm. In addition, the average percentage removal of ES 0.7 mm was 77.24 % for the size of MPs &lt;400 µm and 95.77% for the size of Mps &gt;400 µm. Gaining insight into the mechanisms involved in removing microplastics from drinking water is essential for developing more effective techniques for eliminating them.

Effect of Particle Size and Molarity of Hardening Solution on the Mechanical Properties of New Geopolymeric Mortars Manufactured from Mine Tailings

In this work, the effect of the maximum particle size and the molar concentration of the alkaline hardening solution on the mechanical response in uniaxial compression of geopolymeric mortars manufactured from the geopolymerization of Peruvian mine tailings dust was evaluated. The mechanical results found showed that the average mechanical resistance increased as the molar concentration of the hardening solution increased from 10 to 15M, on the other hand, it was possible to verify that as the particle size of sand and mine tailings is greater, the mechanical resistance values increased. The mechanical data found are in good agreement with the porosity results, that is, as the porosity values increased, the mechanical resistance gradually decreased. The stiffness values reported in the studied geopolymeric mortars showed a slight increase when the values of molar concentration and maximum particle size increased. All the mortars studied presented a similar microstructure, with fine sand particles dispersed within a continuous phase of geopolymer (geopolymerized mining tailings).

Wave‐Driven Vertical Sorting of Density‐Varying Particles

AbstractIt has been recognized that the vertical sorting of polydispersed sand grains via the “Brazil Nut effect” can lead to inverse grading (upward coarsening) in the surface layer of a sand bed. However, the addition of nonnative particles not inherently observed on the beach, characterized by different densities and sizes, may complicate the vertical sorting processes and the fate of the nonnative particles. For example, olivine particles, which may be released on natural sandy beaches to facilitate carbon dioxide capture via weathering from wave action, have a density about 25% larger than the typical native sands. An Eulerian‐Lagrangian model, which couples Computational Fluid Dynamics for the fluid phase and Discrete Element Method for the particle phase was utilized to investigate how the so‐called “Reverse Brazil Nut effect” due to the larger density of nonnative (olivine) particles may be counteracted by the so‐called “Brazil Nut effect” for a range of nonnative particle sizes. Numerical simulations showed that the higher‐density nonnative particles tended to sink into the sand bed consistent with the “Reverse Brazil Nut effect”; however, the vertical sorting structure of native sand, driven by the “Brazil Nut effect,” also was a controlling factor determining the fate of nonnative particles. To maintain the presence of the nonnative (olivine) particles in the active layer of sediment transport, the higher‐density nonnative particle size must be larger than the mean native sand size found at the bottom of the active layer.

Atterberg limits of baseball infield soils containing over-size particles, Part II: effects of sand angularity and uniformity

Context Atterberg limit tests may be useful for evaluating baseball infield soils because these tests directly link soil behaviour to water content. Prior research has demonstrated that the liquid and plastic limits (LL and PL) of sand-clay mixtures are affected by sand properties. However, these studies have used sand exclusively &lt;425 μm and little attention has been devoted to sand angularity or sand-size uniformity. Aims This research tested the effects of sand angularity and sand-size uniformity on the Atterberg limits of infield mixes containing 0–80% sand with much of the sand 425–2000 μm. Methods Experiment 1 compared the effect of mixing angular or round sand of equivalent size with a kaolinitic clay. Experiment 2 compared the effect of mixing one of two sands having a similar average particle size but varying uniformity with an illitic clay. Key results For mixes having equivalent sand content and sand size, the shape of the sand particles did not affect LL (P = 0.47) or PL (P = 0.80). Mixtures with non-uniform sand yielded higher LL than those with uniform sand (mean difference ~0.6% water content g g−1). The mixtures with non-uniform sand also remained plastic at higher sand content (~72.5%) than mixtures with uniform sand (~67.5%). Calculated threshold sand contents for the two sets of mixtures agreed closely with the experiments. Conclusions Sand angularity was shown to be unimportant in this context. When average particle size was held constant, sand uniformity affected the LL water content and the sand content corresponding to a transition between plastic and non-plastic behaviour. Implications This research suggests that baseball field managers need not consider the angularity of sand in an infield mix but should be aware of the uniformity of the sand used to produce the mix as this may influence the mixture’s plasticity.

Microwave Drying Method before Sieving to Obtain Accuracy of Sand Size Parameters

The purpose of this study is to determine the differences between the size parameter findings, comparing the results of a muffle during a 12-h sand-drying process with those of a microwave, because the effectiveness of sand drying with a microwave has not previously been studied. To achieve the best outcomes and assess any inaccuracies, a technique was established. Several power levels and durations were used in the tests. Furthermore, as the median particle size (D50) affects the porosity of sand, samples from three beaches in the south of Spain with varying sand sizes were used in this study. When drying for at least 5 min, the error findings for D50 are less than 3.5%, which is perfectly acceptable for beach nourishment purposes. Regarding power, 462 watts was the optimal power; a lower power, approximately 300 watts, did not completely dry the material, even after nearly 15 min. Furthermore, errors in the sorting (σ) parameter were negligible. It is essential to implement the following recommendations in microwave drying methods: the use of a light and wide container for the sand, interruptions during drying, and a minimum duration of 5 min.

Assessment of sand dunes in Missan Governorate, South-eastern Iraq: Implications for Extraction High Purity Silica

Sand dunes are widely spread in Missan Governorate, South-eastern Iraq in many areas including; Manziliyah, Khazina, Zubadiate, and Chailat. X-ray diffraction (XRD) results of sand samples of sizes 0.063-2 mm, 0.125-0.250mm, and 0.250-0.500mm, revealed that quartz is the main mineral phase, followed by calcite, feldspar and trace of gypsum. Chemically SiO2 is the main oxide in sand of an average 61.36 % while the rest oxides; CaO (14.08%), Al2O3 (6. 76%), Fe2O3 (3.05%), K2O+Na2O (2.30 %) are considered as impurities that could affect the properties of sand. XRD tests indicated the formation of crystalline phase of synthetic silica. XRF showed an increases in SiO2 to 85.37%, while all other oxides (impurities) were reduced to their minimum rate, particularly CaO (1.06 %). Field emission scanning electron microscope (FESEM) and Brunauer-Emmett-Teller (BET) tests indicated the existence of well compiled spherical particles of synthetic silica within the size of 8.55 nm and surface area of 66.51 m2\\g. The medium sand size (0.250-0.500mm) is the appropriate size to produce high purity crystalline silica as it contains the greatest percentage of silica and the low percent of impurities compared to other sizes of sand.

Characterization and classification of three major soils at the college of agriculture, Jalingo, Taraba State, Nigeria

Adequate information on land resources have been identified as a pre-requisite for sustainable land management. The present study was carried out to characterize and classify the soils of College of Agriculture, Jalingo, Taraba State, and to suggest soil management recommendations for optimum crop yield. Digital elevation model (DEM) of the study location was obtained and the slope map of the area generated using ArcGIS (ESRI, US) software. This was used to identify the major soils (MU1, MU2 and MU3). Two soil profile pits were sited in each of MU1 and MU2, and one pit was sited in MU3. The soils were described and sampled for laboratory analyses. The results revealed the dominance of transitional horizons namely; AB, BC and CB which also showed raised proportions of clay. The soils were shallow to bedrock and dominated by brown, dark yellowish brown and gray colours (moist) in the surface soils and reddish to yellowish brown in the subsurface horizons. Sand size fraction dominated the particle size distribution and resulted in sandy loam and sandy clay loam textural classes. All the soils had bulk density &lt; 1.50 g cm−3. Soil pH was slightly acid to neutral and values in water were higher than those in CaCl2 in all horizons. Organic carbon, total N, available P and exchangeable bases were low in most of the soils, while base saturation was high. Two of the soils (MU1 and MU2) were classified as Alfisols while MU3 was classified as an Entisol according to the USDA system. According to the World Reference Base for Soil Resources system of classification, MU1 and MU2 were classified as Lixisols and MU3 as a Gleysol. The incorporation of organic manure, cropping across slopes, and practicing afforestation are recommended for soil nutrient management.

Aerosolized Particulate Matter and Blunting of Ciliary Dynamic Responses: Implications for Veterans and Active Duty Military in Southwest Asia.

Respiratory diseases such as chronic rhinosinusitis and asthma are observed at increased rates in active duty and veteran military members, and they are especially prevalent in individuals who have been deployed in Southwest Asia during Operation Iraqi Freedom and Operation Enduring Freedom. Particulate matter, specifically the fine-grain desert sand found in the Middle East, may be a key source of this pathology because of deleterious effects on mucociliary clearance. With IRB approval, human sinonasal tissue was grown at an air-liquid interface and cultures were exposed to different types and sizes of particulate matter, including sand from Afghanistan and Kuwait. Ciliary dynamic responses to mechanical stimulation and ATP application were assessed following particulate exposure. Particle size of the commercial sand was substantially larger than that of the sand of Afghan or Kuwaiti origin. Following exposure to particulate matter, normal dynamic ciliary responses to mechanical stimulation and ATP application were significantly decreased (P < .01), with corresponding decreases in ATP-induced calcium flux (P < .05). These changes were partially reversible with apical washing after a 16-h period of exposure. After 36 h of exposure to Middle Eastern sand, ciliary responses to purinergic stimulation were completely abolished. There is a neutralization of the dynamic ciliary response following chronic particulate matter exposure, similar to ciliary pathologies observed in patients with chronic rhinosinusitis. Aerosolized particulate matter endured by military personnel in the Southwest Asia may cause dysfunctional mucociliary clearance; these data help to explain the increased prevalence of respiratory pathology in individuals who are or have been deployed in this region.

Research on the Critical Value of Sand Permeability Particle Size and Its Permeability Law after Mixing

The permeability of sand is an important factor in determining the movement and occurrence of liquids and gases in sand. The current work studied the influence of soil particle size and gradation on permeability by testing the permeability of different sand samples that consist of defined sand particles in certain ratios. The results of a total of 640 sets of experiments were analyzed and compared with the corresponding theoretical calculations. We found that the sand can be divided into four groups based on particle size: high-permeability particles, medium-permeability particles, low-permeability particles and non-permeable particles; and the critical particle size of sand for permeability is 0.050 mm. Permeation will be lost when non-permeable particles account for &gt;75% of the total in the mixture of high-permeability particles and non-permeable particles. Permeation will be very easily lost when medium- or low-permeability particles are mixed with non-permeable particles. The current findings are of importance for assessing the permeability of sand based on particle size.

The efficiency of hybrid intelligent models to evaluate the effect of the size of sand and clay metakaolin content on various compressive strength ranges of cement mortar

The efficiency of hybrid intelligent models to evaluate the effect of the size of sand and clay metakaolin content on various compressive strength ranges of cement mortar

Prediction of Beach Sand Particle Size Based on Artificial Intelligence Technology Using Low-Altitude Drone Images

Coastal erosion is caused by various factors, such as harbor development along coastal areas and climate change. Erosion has been accelerated recently due to sea level rises, increased occurrence of swells, and higher-power storm waves. Proper understanding of the complex coastal erosion process is vital to prepare measures when they are needed. Monitoring systems have been widely established around a high portion of the Korean coastline, supported by several levels of governments, but valid analysis of the collected data and the following preparation of measures have not been highly effective yet. In this paper, we use a drone to obtain bed material images, and an analysis system to predict the representative grain size of beach sands from the images based on artificial intelligence (AI) analysis. The predicted grain sizes are verified via field samplings. Field bed material samples for the particle size analysis are collected during two seasons, while a drone takes photo images and the exact positions are simultaneously measured at Jangsa beach, Republic of Korea. The learning and testing results of the AI technology are considered satisfactory. Finally, they are used to diagnose the overall stability of Jangsa beach. A beach diagnostic grade is proposed here, which reflects the topography of a beach and the distribution of sediments on the beach. The developed beach diagnostic grade could be used as an indicator of any beach stability on the east coast of the Republic of Korea. When the diagnostic grade changes rapidly at a beach, it is required to undergo thorough investigation to understand the reason and foresee the future of the beach conditions, if we want the beach to function as well as before.