Sand Samples Research Articles

Geotechnical Properties of Sand-Asphalt for Use in Road Base Layer Instead of Conventional Materials

The study of the geotechnical properties of sand-asphalt for use in road base layer instead of conventional materials, for low to moderate traffic volume, is based on standardized laboratory tests. Sand samples were taken from Kayar, Darou Alpha and Keur Morry (Thies region, Senegal). Identification tests (particle size distribution and sand equivalent) made it possible to select Kayar and Darou Alpha sands which have respective sand equivalent (ES) values of 92 % and 62 %. These values are higher than the minimum required (40 %), for sand-asphalt, with different 35/50 bitumen dosages. The results of the Hubbard-Field test carried out showed that Darou Alpha sands are suitable, with an optimum dosage of 7 % bitumen : the stability at 18 °C, at dry conditions, is 2 732 kg and is greater than the minimum required value of 2 300 kg; the immersion/compression ratio is 85 % and is greater than the minimum required limit of 75 %; water absorption reaches 5.4 % and remains below the maximum required limit of 7 %; the volumetric swelling is 2.6 % and is below the maximum required limit of 5 %. The compactness is 84 % and is acceptable because it exceeds the minimum required limit of 80 %. The sizing carried out with the Alizé©3 software gives deformation values lower than the permissible values. The pavement structure that is placed on a PF3 type platform is therefore correctly sized to support a traffic of 150 heavy vehicles per day for a service life of 15 years. This roadway structure, which is devoid of a foundation layer, includes a 23 cm thick sand-asphalt base layer on which rests a 5 cm thick asphalt concrete. Keywords: sand-asphalt, Hubbard-Field test, Kayar, Darou Alpha, Keur Morry.

Fabrication and Characterization of Colorant-Doped Glass Produced with Local Sand of Nong Phok Site

It is well-known that silica sand is a special type of quartz sand that is suitable for glass fabrication due to its high silica content and low content of iron oxide. In this work, chemical analysis has been carried out on a sand sample from the Nong Phok site, Roi Et province, northeastern Thailand. The geological resources show that this site possesses a surface-to-near surface sand deposit. The grain of fine white sand consists of clear crystals. The grain shape is mainly angular-to-round. Chemical analysis shows that the sand contains more than 99 wt% silica and small amounts of Al, Ca, Ti, and Zr which is in agreement with international standards for glass production. The sand has been used as raw material for the fabrication of soda-lime, lead crystal, and lead-free high refractive index glasses. The colorless and various colored glass products have been satisfactorily used in domestic art and glass manufacturers which promotes local employment and economics.

The effect of multi-walled carbon nanotubes on mechanical properties and water adsorption of lightweight foamed concrete

The paper investigates the impact of carbon nanotube-based modifiers on the performance characteristics of lightweight foamed concrete (LFC). The method involves saturating quartz sand with a solution containing a catalyst for carbon nanotube (CNT) growth, followed by the subsequent chemical vapor deposition (CVD) synthesis of CNTs. Evaluation of nanomodified sand samples was conducted using SEM and TEM, thermogravimetry, Raman spectroscopy, and XRD. Compression and flexural strength tests of (LFC) specimens indicated that the optimal proportion of nanomodified sand introduced is 1% by weight with a particle size of 0.16 mm. This resulted in a notable 35% increase in compressive strength and an approximately 32% improved in flexural strength. Furthermore, the modified sample with CNT-based sand exhibited a 27% reduction in water absorption. The paper also presents a potential mechanism to explain the impact of carbon nanotube-based modified sand on the evolving structure of (LFC).

Evaluation of Geology and Hydrochemistry of Nawfia-Agulu Axis of Anambra State, Southeastern Nigeria

The investigation of the geological, hydrochemical, and engineering characteristics of the Nawfia – Agulu area was carried out. The study aimed at mapping the geology through field data collection, outcrop logging, and laboratory analysis. Consequently, eleven soil and ten water samples were collected and analyzed through particle size distribution test; Atterberg limits tests and hydrochemical analysis to provide insights into the lithology, sediment characteristics, and water quality. The results indicated the dominance of the Ameki/Nanka Formation and Imo Formation as the underlying geology of the study area. The grain sizes of the sand samples ranged from medium to coarse grained, moderately to poorly sorted, and strongly positive to positively-skewed. The depositional environment was nearshore/beach, influenced by nearshore waves and turbulent currents. Engineering properties highlighted the prevalence of uniformly to well-graded soil and moderately to highly plastic behavior, as indicated by the mean plasticity index (PI) value of 26%. These findings suggest potential challenges for infrastructural development in some parts of the area. The water quality indicated slightly acidic water. The physical parameters and the major ions were within the permissible limits of World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ). However, elevated concentrations of heavy metals, including lead, chromium, mercury, iron, and cadmium, in water sources exceeded the respective permissible limits for drinking water indicating contamination/pollution. The dominant water type was Ca2+ – Mg2+– SO42- – Cl– and the dominant hydrochemical process was simple dissolution or mixing and ion-exchange.

Microplastic Particles in Sandy Beaches of Thessaloniki Gulf, Greece

Microplastic pollution is a major issue for aquatic ecosystems. In this study, an assessment of microplastic pollution in beach sediments of Thessaloniki Gulf is presented. Sand sampling was performed in October 2021, in three different coastal areas along the seashore of Thessaloniki Gulf, in NW Aegean Sea. In total, nine sand samples were collected and examined. The morphology of the detected microplastics was recorded: they were fragments and microfibers. Their abundance ranged from 0-32 items/m3. Higher concentrations of microplastics were observed in Karabournaki Beach, located in the city of Thessaloniki. It is the second largest city in Greece, inhabited by about 1,5 million people. Regarding the color, black, red, blue, green, and transparent microplastic fragments were found. Black and blue particles were the most common. Chemical detection and identification were performed with FT-IR spectroscopy. Four polymers were detected: polyethylene (PE), terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP), and polytetrafluoroethylene (PTFE). Polyethylene terephthalate was the dominant identified polymer (50%). The need for plastic pollution management in coastal areas, as well as the need to communicate the issue of plastic marine pollution and enhance public awareness, are discussed.

Assessment and estimation of the effective dose due to external exposure from natural radioactivity of sands used in civil construction in the state of Rio de Janeiro,Brazil

The presence of naturally occurring radioactivity in sand and other building materials results in indoor and outdoor exposure to the public. Sand is one of the main components in civil construction alongside cement, crushed stone and bricks. Thus, this research was carried out in twenty sand samples with the objective of investigating the hazard indices of natural radiation, due to the presence of 238U, 226Ra, 232Th and 40K in sand samples collected in some locations in the state of Rio de Janeiro (Brazil), analyzing by gamma spectrometry and using an HPGe detector. The technique used for gamma analysis was gamma spectrometry, and the software used to analyze peaks and obtain counts was LabSOCS. In this context, the average activity concentration values of 226Ra (66.7 ± 1.2) and 40K (647 ± 31) Bq kg−1 are higher than the world mean activity concentration of 50, 50 and 500 Bq kg−1 for these three radionuclides. However, the value of 232Th (40.6 ± 0.7) Bq kg−1 and Raeq (175 ± 5) Bq kg−1 are less than the world average of 50 Bq kg−1 and 370 Bq kg−1, respectively. The estimation of the average values for Annual Effective Dose (0.51 ± 0.01) and Dutch Radiation Performance Index (0.52 ± 0.01) was carried out, with values below the maximum recommended limit for the public. Only one sample had a higher value and the other samples are within the levels required for environmental control. However, the mean values found in this present study, when compared to those of other authors mentioned here, showed higher values. Therefore, most samples have safe values to be used by people in building their homes.

Estimation of Radiation Dose in Building Materials Used In Federal University Gusau Using Gamma-Ray Spectroscopy Analysis

This study estimated the radiation dose in building materials (sand, cement, and granite) in Federal University Gusau, Zamfara State, Nigeria, through gamma-ray spectrometry system using a Sodium Iodide Thallium activated "NaITl" detector in a low background configuration. The range of the average activity concentration of 226Ra was found to be 56.65±0.75Bqkg-1 to 159.45±2.68Bqkg-1, which was higher than that of the world mean value for soil 35Bqkg-1,for 232Th the range was 46.65±0.45Bqkg-1 to 79.32±1.68Bqkg-1, all the samples, were found to be higher than that of the world mean for soil 30Bqkg-1. While the activity concentrations of 232Th levels of blocks, granite, and sand samples are all above the world range, except the cement which was within the worldwide range 194.84±1.31Bqkg-1 to 656.84±0.76Bqkg-1. The average activity concentration of 40K for cement, sand, and blocks was within the worldwide range, with granite samples slightly higher than the world mean value for soil 400Bqkg-1. The results have been compared with the world mean values of 35, 30, and 400Bqkg-1 specified by the UNSCEAR (2016). Concerning radiological risk to human health, the absorbed gamma dose rate (D) was estimated to be above the world average range of 55nGyh-1; the outdoor annual effective dose equivalent (AEDE) were, estimated to be below the permissible limit of 0.07mSvy-1. The values of Raeq, Hex, and Hin for all the samples in the present work are lower than the accepted safety limit value of 370Bqkg-1 and below the limit of unity, respectively. 

Analysis of Mineral Content and Magnetic Properties of Iron Sand of Bah Bolon Simalungun River, North Sumetera

Analysis and characterization of the natural iron sand of the Bah Bolon River in Simalungun Regency has been carried out. Separation of iron sand is carried out using a 500 Gauss permanent magnet 10 times. After that, the iron sand is washed using Aquades 5 times so that the iron sand is clean of impurities and dried using an oven at a temperature of 85o C for 24 hours. Iron sand samples with a size of 250 mesh (74µm) were then characterized using SEM-EDS and VSM. Measurements using SEM-EDS show that the Sungai Bah Bolon iron sand contains 66.9% Fe, 24.3% O, and 8.8% other elements. Meanwhile, the hysteresis curve from the results of measurements with a Vibrating Sample Magnometer (VSM) shows that the Bah Bolon River iron sand has magnetic saturation (Ms), magnetic remanance (Mr), and coercivity (Hc) properties of 57.70 emu/g respectively 7.09 emu/g, and 129.93 Oe.

The investigation of the frost resistance of the aggregate-sand mixes

Problem. Recently there is a steady trend to the increase of the intensity of traffic and of the loads from the wheels of the rolling stock on the whole structure of the road pavement, therefore during the building of the road pavement layers the most important thing is a rational choice of the materials for the base layers and for the top layers which will provide the performance of the entire structure during the designed service life under the working conditions which are getting worse all the time. Nowadays the most widespread material for the road base layers is aggregate mix strengthened by cement. One of the ways of the base layers materials improving is the increase of their frost resistance. One of the ways to solve this problem can be the different additive and fibers usage as a reinforcing component of the aggregate mix. But until today the influence of the internal factors such as size of mineral grains, granulometric composition and binder content on the indexes of frost resistance is still not investigated.
 Goal. The aim of the research is the investigation of the maximum grain size and content and also mineral binder concentration influence on the indexes of frost resistance of the aggregate mixes strengthened by cement. Methodology. To achieve this goal in the laboratory of the Department of Highway Building and Maintenance named after O. Birulia the samples of sand, fine-grained, medium-grained and coarse-grained aggregate mixes with cement content from 2 to 10 % were prepared. Results. For the frost resistance indexes determination of the aggregate mixes of different compositions strengthened by cement according to the maximum grain size the cement concentration influence on the grade strength indexes was found. The research results have shown that: with the increase of cement content the compressive strength indexes in the fine, medium and coarse-grained mixes are increasing; the increase of the maximum grain size of the same cement concentration shows that compressive strength and tensile strength indexes are increasing. The repeated freezing and thawing is one of the main aggressive factors of the external environment influence which reduces strength and durability of the materials, therefore the influence of this factor on the compressive strength and tensile strength was evaluated. In Ukraine according to the current standard the frost resistance of the aggregate mixes is evaluated only in terms of compressive strength index of samples which were subjected to certain number of freeze-thaw cycles. It is determined that the aggregate mixes with the same cement content with larger mineral grains in its composition have higher indexes of the frost resistance coefficient. Also it was found that the influence of the freeze-thaw cycles is more informatively shown at the samples testing according to the split tensile test. Conclusions: 1. The increase of the binder content in the composition of strengthened aggregate mixes leads to the decrease of the freeze-thaw cycles influence on the compressive strength and splitting strength for all studied compositions of aggregate mixes. 2. The aggregate mixes strengthened by the same cement amount with the larger size of mineral grains in its composition have higher values of frost resistance coefficients in comparison with strengthened aggregate mixes with smaller maximum size of mineral grains in its composition. 3. The influence of the freeze-thaw cycles is showed more informatively by the split tensile scheme.

Experimental study on the influences of cutter geometry and material on scraper wear during shield TBM tunnelling in abrasive sandy ground

When shield TBM tunnelling in abrasive sandy ground, the rational design of cutter parameters is critical to reduce tool wear and improve tunnelling efficiency. However, the influence mechanism of cutter parameters on scraper wear remains unclear due to the lack of a reliable test method. Geometry and material optimisation are often based on subjective experience, which is unfavourable for improving scraper geological adaptability. In the present study, the newly developed WHU-SAT soil abrasion test was used to evaluate the variation in scraper wear with cutter geometry, material and hardness. The influence mechanism of cutter parameters on scraper wear has been revealed according to the scratch characteristics of the scraper surface. Cutter geometry and material parameters have been optimised to reduce scraper wear. The results indicate that the variation in scraper wear with cutter geometry is related to the cutting resistance, frictional resistance and stress distribution. An appropriate increase in the front angle (or back angle) reduces the cutting resistance (or frictional resistance), while an excessive increase in the front angle (or back angle) reduces the edge angle and causes stress concentration. The optimal front angle, back angle and edge angle for quartz sand samples are α = 25°, β = 10° and γ = 55°, respectively. The wear resistance of the modelled scrapers made of different metal materials is related to the chemical elements and microstructure. The wear resistances of the modelled scrapers made of 45#, 06Cr19Ni10, 42CrMo4 and 40CrNiMoA are 0.569, 0.661, 0.691 and 0.728 times those made of WC-Co, respectively. When the alloy hardness is less than 47 HRC (or greater than 58 HRC), scraper wear decreases slowly with increasing alloy hardness as the scratch depth of the particle asperity on the metal surface stabilizes at a high (or low) level. However, when the alloy hardness is between 47 HRC and 58 HRC, scraper wear decreases rapidly with increasing alloy hardness as the scratch depth transitions from high to low levels. The sensitive hardness interval and recommended hardness interval for quartz sand are [47, 58] and [58, 62], respectively. The present study provides a reference for optimising scraper parameters and improving cutterhead adaptability in abrasive sandy ground tunnelling.

Natural Radioactivity Levels of the Beach Sands of Cleopatra Beach and Damlatas Beach (Türkiye) and Their Impact on Human Health.

HPGe γ spectrometry method was used to measure the natural radioactivity levels (40K, 232Th, and 226Ra) of the beach sand samples from Cleopatra Beach and Damlatas Beach in Antalya (Türkiye). The mean 40K, 232Th, and 226Ra radioactivity levels of the studied samples were calculated as 276.88 ± 17.24, 25.04 ± 2.88, and 17.06 ± 1.68 Bq/kg, respectively. Being below the radiation limits, these values indicate no risk in terms of public health. Moreover, the radiological risk parameters, such as excess lifetime cancer risk, radium equivalent activity (Raeq), absorbed γ dose rate (D), annual effective dose equivalent (Eaed), γ index (Iγ), internal radiation hazard index (Hin), and external radiation hazard index (Hex), were calculated. The values of all of these parameters were found to be below the internationally accepted radiation limit values. In addition, distribution maps showing the radiological situation of the region were generated although they did not pose a hazard to public health. No results were found in the analysis processes related to artificial radioactivity.

Tourism impact on coastal erosion: a case of Alanya

Sandy coasts are constantly exposed to rapid coastal change. Projected climate change caused by Changes in sea level rise, wave circumstances, and storm occurrences will increase erosion rates, exposing these areas to increasingly hazardous conditions. For coastal management purposes, it is important to monitor and measure these changes. Erosion of sandy and pebbly beaches and their ecosystems. The loss of sand and gravel is not only due to the rise in sea level and the force of waves resulting from storms, which will intensify due to climate change. There is a new important factor of human intervention and impact on the beaches that must be mentioned and verified as to how the effect is in the long term with the increase in tourism in the coastal areas, especially in areas of a tourist nature. The amount of sediment that each individual transports from the coastal beaches in the Alanya region.
 In the experiment, we Collected samples of sand and gravel from different locations on the coast to be surveyed. Classifying the collected samples by means of sieve analysis. Executing the project by going to the sites of sand samples that were analyzed in different periods by collecting samples (collecting sand attached to the bodies of people of different sizes in basins Testing). The thesis also answers Identify the eroded beach by relating the average number of locals and foreigners who come to the project area for a year and use the coast with the data collected during the project.

Experimental determination of friction at the interface of a sand-based, seismically isolated foundation

AbstractThis paper describes the results of an experimental investigation on the coefficient of friction at the interface of a PVC–sand–PVC layer that is utilised as part of a low-cost geotechnical seismic isolation devised to be used in low-income countries. The PVC–sand–PVC configuration consists of two smooth PVC surfaces enclosing a single layer of sand grains, with surface densities between 0.5 kg/m2 and 3 kg/m2, which aim to facilitate relative sliding at friction resistance between 0.15 and 0.30 depending on the design acceleration, by acting like “non-perfectly rounded ball bearings”. The latter isolation method has been extensively studied both numerically and experimentally by means of large-scale testing at the shaking table of the EQUALS Earthquake Laboratory of the University of Bristol. However, in the light of the construction of the first building worldwide to be designed and constructed in Nepal with the particular low-cost PVC–sand–PVC sliding interface, it was deemed necessary to reliably assess the mean and dispersion of the coefficient of friction as a function of vertical pressure, sand density and degree of saturation. The results of the tests performed using an improved direct shear apparatus are presented herein using sand samples and PVC sheets that were locally resourced in Nepal to be used in construction. The results indicate that the variation of friction is reasonably low and in any case within the desirable range, irrespectively of the parameters examined, thus establishing confidence to the forthcoming design of the novel isolated building.

Performance evaluation of a sand energy storage unit using response surface methodology

The utilization of affordable and cost-effective storage materials is a crucial factor in the development of such systems. In this study, the influence of coil pitch, inlet fluid temperature and hot fluid velocity on sand based thermal energy storage (TES) unit is investigated, using experimental results and theoretical models. The experimental segment of this study focuses on measuring the thermophysical properties of two sand samples obtained from different locations within the United Arab Emirates. A conjugated heat transfer model is developed to predict TES using the experimentally measured sand properties. A regression model utilizing response surface methodology (RSM) approach is developed to represent the energy stored per kilogram of sand as a function of the input factors. Furthermore, an optimization algorithm is employed to determine the optimal values of input factors that maximize the energy storage density. The results reveal that the three factors (fluid inlet temperature, velocity, and number of coil turns) significantly affect the stored thermal energy. The RSM analysis illustrates that maintaining high levels of both inlet temperature and fluid velocity maximizes the energy stored. Similarly, keeping inlet temperature and coil turns at the high level maximizes the energy stored. The optimized sand energy storage unit mass reaches 6.348 kJ/kg after an 8-h charging period, with an associated pressure drop of 71.4 Pa for the currently designed unit.

Mechanical Analysis of Sand Ripples Deposits in the Lower Basin of Wadi Tilal "Geomorphological study"

The current study is set to determine the volumes of sand ripple deposits in the lower basin of Wadi Tilal in micro depositional environments by mechanical analysis. To do so, the present study analyzed samples of sediment in the laboratory using an electric sieve and the dry sieving method. The results were then calculated in the Phi unit to be processed using the Fraction V.3 program combined with the Folk & Ward equations in order to find out an estimation of the volume coefficients, and categories of statistical coefficients for the volumes of sediment sand. The study’s main findings was that the medium-sized sand category (1-2ø) constitutes about 44.75% of the weight of the ripple sand samples, and that the average sand size is about (1.698ø) and it falls within the medium-sized sand category. Moreover, the average value of the sorting coefficient was (0.873ø), which falls within the medium sorting category. In addition, most of the distribution curves fell within the high positive skewness category with an average of (0.336ø), and the value of the flattening coefficient was (1.265ø). The shape of the distribution curve falls within the category of flattened and sharpen end.

The role of abrasion and resident fines in dust production from aeolian sands as measured by the Portable in situ Wind Erosion Laboratory (PI-SWERL)

Aeolian deposits are important sources of atmospheric dust, particularly from extensive dune fields, interdune areas and vast sand sheet deposits across the globe. This study quantified the total suspended particle flux (TSP), particulate matter <10 μm (PM10) and PM2.5 emissions with the Portable in situ Wind Erosion Laboratory (PI-SWERL) for eighteen different types of sand to determine the role of aeolian abrasion in dust production. Aeolian abrasion results in grain coating removal, chipping, and spalling of sand grains during saltation transport, producing dust-sized particles. The studied sands were poorly- to well-sorted, round to angular, coarse to fine sand composed of quartz-rich to gypsum-rich particles. Some sand samples contained up to 14 % silt and clay, referred to as resident fines. Experiments on sand with diverse characteristics elucidated dust production processes. Samples composed of 100 % sand produced dust by aeolian abrasion with fluxes of 0.2–2.5 mg m−2 s−1 indicating aeolian abrasion as a potentially important process contributing to dust storms and desert loess deposits. Sand containing resident fines produced up to 42 mg m−2 s−1, an order of magnitude more dust than clean sand samples, with >60 % of the dust produced by the release of silt and clay and up to 40 % from aeolian abrasion. These high fluxes rival dust storms emanating from playas like Owens Lake in California. Climate change and anthropogenic disturbance of stabilized aeolian sand deposits in arid lands will likely result in increased dust emissions in the future which should be parameterized in climate models.

Acetaminophen-traces bioremediation with novel phenotypically and genotypically characterized 2 Streptomyces strains using chemo-informatics, in vivo, and in vitro experiments for cytotoxicity and biological activity

We isolated two novel bacterial strains, active against the environmental pollutant acetaminophen/Paracetamol®. Streptomyces chrestomyceticus (symbol RS2) and Flavofuscus (symbol M33) collected from El-Natrun Valley, Egypt—water, sediment, and sand samples, taxonomically characterized using a transmission electron microscope (TEM). Genotypic identification, based on 16S rRNA gene sequence analysis followed by BLAST alignment, were deposited on the NCBI as 2 novel strains https://www.ncbi.nlm.nih.gov/nuccore/OM665324 and https://www.ncbi.nlm.nih.gov/nuccore/OM665325. The phylogenetic tree was constructed. Acetaminophen secondary or intermediate product’s chemical structure was identified by GC/LC MS. Some selected acetaminophen secondary-product extracts and derived compounds were examined against a panel of test micro-organisms and fortunately showed a good anti-microbial effect. In silico chemo-informatics Swiss ADMET evaluation was used in the selected bio-degradation extracts for absorption (gastric), distribution (to CNS), metabolism (hepatic), excretion (renal), and finally not toxic, being non-mutagenic/teratogenic or genotoxic, virtually. Moreover, in vitro cytotoxic activity of these selected bio-degradation secondary products was examined against HepG2 and MCF7 cancer cell lines, where M33 and RS2 extract effects on acetaminophen/paracetamol bio-degradation products were safe, with higher IC50 on HepG2 and MCF7 than the acetaminophen/paracetamol IC50 of 108.5 μg/ml. Moreover, an in vivo oral acute single-dose toxicity experiment was conducted, to confirm these in vitro and in silico lower toxicity (better safety) than acetaminophen/paracetamol.

Seasonal Variation in Fungi in Beach Sand in Summertime: Stintino (Italy)

Background: The goal of this study was to monitor the microbial biodiversity in beach sand that is heavily visited by tourists during the summer, and to determinate whether the high presence of bathers (around 5000 per day) can modify sand microbial composition. Methods: Between 2016 and 2020, 150 sand samples were collected from nine different points at La Pelosa beach in Sardinia, Italy. Non-culturing methods were used; DNA extraction and meta-barcode sequencing were performed. All samples were analyzed with sequencing methods for 16S and ITS sequences. Results: Fungal genera differ on the three beaches and in the winter/summer zones. The ITS sequence showed the most common presence of Candida during summer and Paradendryphiella in the winter. The greatest diversity was found in the dune during winter, while in other parts of the beach, there are differences between bacteria and fungi, particularly in the wash zone during the winter, with high diversity for 16S sequences but low diversity for ITS sequences. Conclusions: It appears reasonable that the sands, even on non-urban beaches, should be included in health monitoring programs in addition to the waters, and that access to them should be regulated by limiting the number of bathers with the aim of reducing the presence of pathogenic fungal species.

The Effects of Silica Sand Particle Size on Drying Using a Vertical Fluid Bed Dryer

The experimental and theoretical relationships of silica sand particle size and drying was compared to predict the minimum fluidization rate in drying at 9.57% moisture. The drying temperature (90°C, 120°C, and 150°C) and particle size (274 ± 0.5 μm, 563 ± 0.5 μm, and 910 ± 0.5 μm) parameters were studied as factors influencing the drying process in the experiment. Upon comparing all the test results, it was found that moisture loss accelerated as drying temperature of the silica sand samples increased. On the other hand, the minimum fluidization rate was found to have varied directly with particle size, in addition to being inversely proportional to temperature. Moreover, it was observed that pressure increased with increasing particle diameter and reduced with decreasing temperature.

Study on the impact of moulding parameters on the flow property of green sand mould

ABSTRACT The efficiency of green sand mould determines the process performance of sand casting. It is important to have a high flowability level of the green sand to ensure a well-distributed green sand mould around the model cavities. The study's novelty lies in using the factorial design of experiments to correlate green sand flowability with moulding parameters and employing practical approaches. This method reveals how moulding parameter variations affect sand flowability and green sand behaviour under different conditions. The research examined different factors involving sand grain size, water content, bentonite binder material content, and mixing time. Two experimental methods were used to evaluate the variation of sand moulding parameters on the flowability of the green sand. The first method used a Levelink apparatus to extrude the green sand mixture through four holes. The second method based on the relative hardness of the graded sand samples is related to the Orlov test. The results obtained showed a good relationship between these two tests for determining the flowability of the green sand. Enhancing flowability was carried out by increasing the grain size of the sand used, and reducing the water ratio, bentonite percentage, and mixing time.