Sieve Particles Research Articles

Element behavior during autoclave oxidation of polymetallic sulfide flotation concentrate containing tungsten and molybdenum

In this paper, we investigate the behavior of associated elements (tungsten, molybdenum, and bismuth) contained in a sulfide gold-bearing concentrate during its autoclave oxidation. The process is studied using a sulfide flotation concentrate, crushed to a particle sieve mesh size of minus 0.045 mm and containing 22.1 g/t of gold, 133.2 g/t of silver, 2.7% of tungsten, 13% of molybdenum, and 0.7% of bismuth. The process was carried out in a 2 dm3 autoclave at a temperature of 220ºC and an oxygen partial pressure of 0.7 MPa. The concentrations of sulfuric acid and iron ions in the solution were determined by titrimetric analysis. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentrations of bismuth, tungsten, molybdenum, copper, silver, and arsenic in the solution, as well as the content of bismuth, tungsten, molybdenum, copper, arsenic, lead, and iron and sulfur forms in the cake. The cake was also examined using diffraction analysis. Experiments on cyanidation of oxidized cake were carried out in the pH range of 10.0–10.5 and a NaCN concentration of 1 g/dm3 with a PuroliteS992 ion exchange resin for 24 h. Autoclave oxidation experiments showed the sulfide oxidation degree to be higher than 99%. Extraction of molybdenum into solution in the form of [MoO2(SO4)n]-(2n-2) and MoO 2+ amounted to 95%. The decrease in the solid mass led to an increase in the concentration of bismuth and tungsten in the cake, with their contents reaching 1.66% and 12.7%, respectively. The main phases in the cake were established to be scheelite, anhydrite, plumboyarosite, and bedantite. The extraction of precious metals at the subsequent cyanidation stage amounted to 97.5% of gold and 91.6% of silver. Therefore, autoclave cyanide processing of sulfide gold-containing concentrates leads to a molybdenum extraction in the autoclave oxidation solution at the level of 95%. During cyanidation, more than 90% of gold and silver are extracted. Due to the significant amount of tungsten (17%), bismuth (0.9%), lead (5.3%), and molybdenum (3.3%), the obtained cake cannot be considered a waste product.

Study on the Adsorption of Trace Water in N-Methyl-pyrrolidone Solvents by A-Type Molecular Sieves.

N-Methyl-pyrrolidone (NMP) is an important coating solvent for the production of lithium batteries, and its water content will greatly affect the coating quality and energy density of lithium batteries, which needs to be reduced to 200 ppm. The current vacuum distillation technology suffers from high operating costs and high energy consumption, whereas the pervaporation technology only achieves solvent dehydration up to 99.5%. Therefore, it is of great significance to carry out the study of trace water removal from NMP solvents. In this paper, the A-type molecular sieve adsorption method was used to remove trace water from the NMP solvent, and the effects of molecular sieve type, particle size, adsorption temperature, feeding amount, and contact time on the dehydration performance of NMP system were first investigated. Adsorbed at 25 °C for 240 min at a feeding amount of 120 g/L, 3A molecular sieves were able to reduce the water content of the NMP solvent from 5000 to 140 ppm. Second, Langmuir and Freundlich equations were used to fit the static isothermal adsorption data, and the results showed a better correlation of the Langmuir equation. Then, the adsorption kinetics and diffusion mechanism were analyzed by the kinetic model and the Crank single-pore diffusion model. The R2 of the pseudo-first-order kinetic model was 0.9993, which was more suitable for describing the process of adsorption of water from the NMP solvent by 3A molecular sieves, and the effective diffusion coefficient De = 2.986 × 10-8 cm2/s was calculated for the Crank single-pore adsorption model, which proved water molecules on the 3A molecular sieve. The diffusion of water molecules on the inner surface of the pores is the controlling step of the adsorption process. Finally, the fixed-bed dynamic penetration curves were investigated to obtain the experimental data of fixed-bed adsorption, and the experimental data were fitted using the Thomas and Yoon-Nelson models, which showed that both models could describe the adsorption behavior of trace water in NMP solvents on 3A molecular sieves. This study provides a new idea for the removal of trace water in NMP systems, and a series of model fitting parameters provide basic data for industrial scale-up.

Particle shape and clogging in fluid-driven flow: A coupled CFD-DEM study

Clogging is a critical issue in the flow of particulate matter. This study uses the computational fluid dynamics coupled with discrete element method (CFD-DEM) to investigate how particle shape affects clogging behavior. Settling tests were conducted to confirm the dynamic behavior of irregular particles, modeled using the bonded-sphere method, in flow. The particle shape features were classified into form, roundness, and surface texture. The results demonstrate that sieving mechanisms, particle locking, and friction effects resulting from particle shape significantly impact microscopic clogging behavior. Irregular particles also increase the filter cake’s porosity, resulting in a higher flow rate at the orifice and an elevated probability of macroscopic clogging. This study enhances our understanding of the effect of particle shape on clogging with both microscopic and macroscopic evidence.

Particle Behavior and Aperture Optimization of Variable Vibration-Amplitude Screening Based on Discrete Element Method Simulation.

Recently, some novel screens were proposed based on the improved understanding of screening processes from particle-scale studies, one of which is the novel variable amplitude equal thickness vibration screen (VAETVS). This paper presents an investigation of using different aperture sizes to further optimize the VAETVS by the discrete element method (DEM). The screen was divided into three panels, and the aperture size of each panel was varied in the simulation. The particles' dynamics and spatial distribution were investigated to better understand the effects of varied amplitudes and aperture sizes on the screening efficiency. The results showed that the VAETVS can be effectively optimized by varied amplitude as well as varied aperture size for different screen panels. The amplitude variance is more effective for hard sieve particles and hindrance particles. It is also found that from the feed end to the discharge end, the difference in the distribution of particle mass between the coarse particles and the fine particles increases. Generally, such a difference can be increased with increasing aperture sizes. However, the effects of the apertures of the different panels were not the same. The simulated data were further analyzed by the Box-Behnken response surface method, which gave a mathematical model to predict the screening efficiency η with the varied apertures. From the model, the optimal aperture sizes are 7.5, 7.58, and 6.81 mm, yielding the maximum screening efficiency of 86.35%, and the optimal opening areas for the three panels are 35, 40, and 40%, respectively, yielding the maximum screening efficiency of 87.82%.

The potential of in-house pectinolytic enzymes for industrial application

Pectinases are one of the essential groups of enzymes in the field of biotechnology and have applications in various industries including food, textile, paper industries, and waste management. Pectinases, like other industrial enzymes, are usually expensive. This research aimed at producing in-house pectinase from waste fruits, by an inductive mechanism. The study specifically optimized the production of in-house pectinases from mango and pawpaw peels used as substrates and also demonstrated the hydrolytic potential of the substrate-based in-house pectinase enzymes through viscosity analysis. The mango and pawpaw peels obtained from Blue Skies Co. Ltd. were oven-dried and milled to sieve particle sizes depending on the mode of the fermentation process. Measured amounts of the substrates were put into 50 ml Falcon tubes and subjected to both solid-state and submerged fermentation processes. The substrates were inoculated with one milliliter of Aspergillus niger isolate suspension and incubated at 30 °C for 2, 4, 6, 8, and 10 days under both fermentation processes. The crude enzyme extracts (in-house pectinolytic enzymes) obtained from the mango and pawpaw peels of both fermentation processes were used as enzyme sources for the hydrolysis of 1% w/v pectin solution prepared in phosphate buffer, pH 6.8 at 40 °C in viscosity analysis. The viscosities of the various treatments were recorded at different time intervals of 10, 20, and 30 min. Based on the viscosity analysis, it was observed that pectinolytic enzymes from pawpaw peels showed higher pectinolytic potential relative to the mango counterpart for both fermentation processes. However, there were consistent optima at day 4 for the mango peels and day 6 for the pawpaw peels using the submerged fermentation process. Also, there was a linear correlation between the pectinolytic activity and incubation period. The results obtained from this study show a higher potential to produce pectinases from agro-wastes such as mango and pawpaw peels for industrial purposes using an appropriate fermentation process.

Crystallization-controlled fusion mechanism of the amorphous fly ash from the Shell coal gasifier by particle sieving

The mineral in coal is transformed to the fly ash of different particle sizes during the entrained flow coal gasification, causing the ash deposition problem on the radiant syngas cooler. In this study, the fusion behavior of fly ash collected from a Shell coal gasifier was analyzed by particle sieving. Results indicated that the fusibility of amorphous fly ash was influenced by the anorthite crystallization at high temperature. The fusion process of fly ash particle was divided into the sintering stage, plateau stage, and melting stage, which were caused by the flow of the amorphous fly ash, anorthite crystallization, and anorthite melting, respectively. The high theoretical anorthite content and the low fly ash viscosity improved the anorthite crystallization reaction in the fly ash particles <45 μm, resulting in a wide plateau stage, narrow melting stage, and high ash fusion temperatures (AFTs). Therefore, the fusion behavior of fly ash particles <45 μm followed “melting-dissolution” mechanism. In contrast, the fusion of fly ash particles >45 μm belonged to the “softening-melting” mechanism for the weak anorthite crystallization behavior. The fly ash particles <45 μm may cause the serious ash deposition problems for its low viscosity.

Contour–Context Joint Blind Image Inpainting Network for Molecular Sieve Particle Size Measurement of SEM Images

Scanning electron microscope (SEM) images generated in the experiment of high-throughput molecular sieves catalysts contain particle size information of various molecular sieves. However, a certain proportion of molecular sieves in SEM images are occluded due to their characteristics of cluster distribution, which cause difficulties to measure the particle size of these occluded molecular sieves. In this paper, we leverage the image inpainting technique to reconstruct missing regions, and then calculate the particle size. Aiming at the problem that the generated regions of recent image inpainting methods exist blurriness in contour and context, we propose a contour-context joint blind image inpainting network, which is specifically a two-stage model with full utilization of edge information to reconstruct the contour and context of these occluded molecular sieve images. In the first stage, the edge of occluded region is reconstructed. In the second stage, the reconstructed edge is introduced through down sampling and skip connection to generate images with complete contour. Meanwhile, a novel encoder loss is proposed to motivate the encoder to extract more reasonable features. Compared with the existing methods, our model achieved more integral results visually and higher quantitative metrics. Thus, our approach can accurately predict the particle size from reconstructed molecular sieve images.

Phononic-Crystal-Based Particle Sieving in Continuous Flow: Numerical Simulations.

Sieving specific particles from mixed samples is of great value in fields such as biochemistry and additive manufacturing. In this study, a particle sieving method for microfluidics was proposed based on a phononic crystal plate (PCP), the mechanism of which originates from the competition between the trapping effect of the resonant PCP-induced acoustic radiation force (ARF), disturbance effect of acoustic streaming (AS), and flushing effect of the continuous inlet flow on particles suspended in microfluidic channels. Specifically, particles with different sizes could be separated under inlet flow conditions owing to ARF and AS drag forces as functions of the particle diameter, incident acoustic pressure, and driving frequency. Furthermore, a comprehensive numerical analysis was performed to investigate the impacts of ARF, AS, and inlet flow conditions on the particle motion and sieving efficiency, and to explore proper operating parameters, including the acoustic pressure and inlet flow velocity. It was found that, for each inlet flow velocity, there was an optimal acoustic pressure allowing us to achieve the maximum sieving efficiency, but the sieving efficiency at a low flow velocity was not as good as that at a high flow velocity. Although a PCP with a high resonant frequency could weaken the AS, thereby suiting the sieving of small particles (<5 μm), a low channel height corresponding to a high frequency limits the throughput. Therefore, it is necessary to design a PCP with a suitable resonant frequency based on the size of the particles to be sieved. This investigation can provide guidance for the design of massive acoustic sorting mi-crofluidic devices based on phononic crystals or acoustic metamaterials under continuous flow.

Influence of Rice Husk Ash Fines on Geotechnical Properties of Lime Stabilized Lateritic Soil

Different fines of rice husk ash (RHA) are typically used as a binder for soil stabilization. This study aims to assess the performance of RHA fines as a binder with lime in the improvement of plasticity and compaction characteristics of stabilized soil. Consistency limits, particle sieve analysis, and compaction tests were conducted on the natural lateritic soil, while consistency limits and compaction tests were conducted on the stabilized lateritic soil. The tests conformed to BS 1377 (1990). The chemical compositions of the RHA were assessed. Lateritic soil samples were mixed with lime in the proportions of 2, 4, 6, 8, and 10% by weight of dry soil. Plasticity Index (PI) was used as the determinant of optimum performance of lime-stabilized lateritic soil and this was obtained at 8% of lime addition. Thereafter, binder ratios (Lime: RHA) of 0:8, 2:6, 4:4, 6:2, and 8:0 were employed in the blending of the lateritic soil. The Plasticity Index (PI) of the stabilized soil were generally lowered to 7.82%, 21.36%, 18.97%, 19.71%, 15.03% when stabilized with BR2:675μm, BR4:475μm, BR6:275μm, BR2:6300μm and BR6:2300μm respectively. All binder ratios containing both lime and RHA size of 75 μm reduced the PI. Also, the effect of all binder ratios containing both lime and all RHA sizes showed increment in the Maximum Dry Density (MDD). Similarly, soil stabilized with BR2:6150μm, BR4:475μm, BR4:4150μm, BR4:4300μm, BR6:2150μm and BR6:2300μm offered a lowered OMC. 75μm RHA and BR4:475μm had the potential to improve Lime-RHA stabilized lateritic soil mixture especially for road application.

Self-driven lithium extraction by directional liquid transport nonwoven

•Self-driven lithium extraction was enabled by a composite asymmetric nonwoven (CAN) •CAN saves energy costs by avoiding extra pressure in lithium extraction •CAN’s design simplicity enables good chemical stability and long service life Lithium extraction from seawater/brine has attracted increasing attention because of its abundant reserves. However, most extraction technologies require extra energy consumption to enrich lithium in the solution. Here, we develop a self-driven lithium extraction method by a composite asymmetric nonwoven (CAN) with directional liquid transport functionality. CAN consists of one hydrophobic fibrous layer containing Li-ion sieve particles and one hydrophilic fibrous layer. As a result, a solution containing various types of ions can spontaneously transport through CAN from the hydrophobic to the hydrophilic layer, absorbing Li ions in the hydrophobic layer. CAN exhibits high Li+ selective adsorption capacity, good chemical stability, easy recyclability, and long service life. Importantly, extremely low energy of ∼1.631 J is consumed on extracting 1 mg lithium ion by our method using CAN. This work opens a great promise of saving huge energy costs on lithium extraction from seawater or salt lakes. Lithium extraction from seawater/brine has attracted increasing attention because of its abundant reserves. However, most extraction technologies require extra energy consumption to enrich lithium in the solution. Here, we develop a self-driven lithium extraction method by a composite asymmetric nonwoven (CAN) with directional liquid transport functionality. CAN consists of one hydrophobic fibrous layer containing Li-ion sieve particles and one hydrophilic fibrous layer. As a result, a solution containing various types of ions can spontaneously transport through CAN from the hydrophobic to the hydrophilic layer, absorbing Li ions in the hydrophobic layer. CAN exhibits high Li+ selective adsorption capacity, good chemical stability, easy recyclability, and long service life. Importantly, extremely low energy of ∼1.631 J is consumed on extracting 1 mg lithium ion by our method using CAN. This work opens a great promise of saving huge energy costs on lithium extraction from seawater or salt lakes.

High flexural strength lightweight fly ash geopolymer mortar containing waste fiber cement

This study aims to investigate the use of waste fiber cement (WFC) in making high flexural strength lightweight fly ash geopolymer mortar. The WFC was crushed and passed a No. 4 sieve (particle size of 0.12–4.75 mm) for use as a fine aggregate with a low bulk density of 1124 kg/m3. It was used to replace river sand at 0–40% by volume for making geopolymer mortar with alkaline solution to fly ash ratio of 0.7 and sodium hydroxide to sodium silicate ratio of 1.0. Their properties were tested and compared with those of Portland cement mortars. The results indicated that the workability, density, and strength of mortars decreased with an increase in WFC contents. The geopolymer mortars with 30% WFC had a density of 1789 kg/m3, compressive strength of 17.7 MPa, and high flexural strength of 3.4 MPa. With higher WFC content of 40%, the density and compressive strength were reduced to 1750 kg/m3 and 13.3 MPa, respectively, with the flexural strength of 2.8 MPa. The incorporation of 30–40% WFC resulted in the lightweight mortar with a very high flexural strength of around 20% of compressive strength. Furthermore, the use of WFC as recycled aggregate in the geopolymer-based system exhibited better thermal insulation, sound absorption, and acid resistance than in the Portland cement-based system. The developed geopolymer mortars containing WFC in this study were appropriate for use as lightweight mortars with thermal and sound insulating properties.

Spray-drying assisted layer-structured H2TiO3 ion sieve synthesis and lithium adsorption performance

A spray-drying assisted solid-state method to prepare spherical layer-structured H 2 TiO 3 ion sieve (LSTIS) particles is reported herein. The effects of synthesis parameters (calcination temperature, calcination time, and the lithium-titanium molar ratio) on adsorption–desorption performance (the delithiation ratio, titanium dissolution loss, and the adsorption capacity) were investigated. The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g −1 (average of 25.85 mg·g −1 over 5 cycles) and ultra-low titanium dissolution loss of less than 0.12% (average of 0.086% over 5 cycles). The LSTIS showed excellent selectivity toward Li + in Na + , K + , Mg 2+ , and Ca 2+ coexisting saline solutions where its adsorption capacity reached 27.45 mg·g −1 and the separation factors of Li + over the coexisting cations exceeded 100. The data suggests that the LSTIS is promising to competitively enrich Li + from saline solutions.

Long-Life Aqueous Zn-I2 Battery Enabled by a Low-Cost Multifunctional Zeolite Membrane Separator.

Aqueous zinc iodide (Zn-I2) batteries are promising large-scale energy-storage devices. However, the uncontrollable diffuse away/shuttle of soluble I3- leads to energy loss (low Coulombic efficiency, CE), and poor reversibility (self-discharge). Herein, we employ an ordered framework window within a zeolite molecular sieve to restrain I3- crossover and prepare zeolite molecular sieve particles into compact, large-scale, and flexible membranes at the engineering level. The as-prepared membrane can confine I3- within the catholyte region and restrain its irreversible escape, which is proved via space-resolution and electrochemical in situ time-resolution Raman technologies. As a result, overcharge/self-discharge and Zn corrosion are effectively controlled by zeolite separator. After replacing the typically used glass fiber separator to a zeolite membrane, the CE of Zn-I2 battery improves from 78.9 to 98.6% at 0.2 A/g. Besides, after aging at the fully charged state for 5.0 h, self-discharge is restrained and CE is enhanced from 44.0 to 85.65%. Moreover, the Zn-I2 cell maintains 91.0% capacity over 30,000 cycles at 4.0 A/g.

Effects of Evaporative Cooling Air Conditioning on Classroom Pollutants and Thermal Environment.

Indoor particles and carbon dioxide concentration are major indices to evaluate indoor air quality. Based on the two-dimensional filler sieving model of the direct evaporative cooling segment, the porous media model was used for the simulation of the water filler section, the filtering efficiency of particle was simulated by adjusting the water drenching density and airflow velocity in different operating conditions. The three-dimensional classroom model used to change the exhaust outlet position and control the use of air conditioners simulated the indoor thermal environment and the changes in pollutant concentration. The Euler method and Lagrangian method were used to analyze the indoor flow field and particle sieving in the direct evaporation section, respectively. Conclusions show that in the application of evaporative cooling and stratum ventilation air conditioning system in classroom, the position of the exhaust port affects the concentration of carbon dioxide in the student’s breathing area. The water filler section can effectively reduce the concentration of particle and carbon dioxide supplied indoors. The filtration efficiency of particle in outdoor air passing through the direct evaporative cooling section based on diffusion, inertial collision, and interception is affected by the combined effect of particle size, onward wind speed, and water spray density. The filtration efficiency of particle increases as the density of the spray water increases. With the increase of head-on wind speed, the filtration efficiency of coarse particulate matter is higher than that of fine particulate matter. The research results help policy makers decide whether to install evaporative cooling air conditioning in schools and determine which exhaust outlet positions are most effective in improving indoor air quality.

Nanoporous membrane fabrication by nanoimprint lithography for nanoparticle sieving.

An isoporous membrane with strictly controlled pore size, shape and distribution could provide an efficient, precise and mild sieving of particles in nanotechnology and biomedical applications. However there is a lack of highly porous polymeric membranes combining isoporosity and high permeance in the range below 500 nm. Track-etched membranes are practically the only commercial option. Membranes prepared by phase inversion typically have a broad pore size distribution. Most nanofabrication methods have limited the preparation of membranes with pores in the micrometer range. In this work, we present a nanotechnology-based fabrication methodology to manufacture a stable and flexible nanoporous polymeric membrane with 300 nm isopores using UV nanoimprint lithography. The highly porous membrane has a pore density of 4 × 109 pores per cm2 and stable permeance of 108 000 L m−2 h−1 bar−1. Uniform ZIF-8 nanoparticles were synthesized and the isoporous membrane successfully demonstrated as high as 100% rejection and size-based sieving performance of nanoparticles.

Effect of particle size and weight percentage variation on the mechanical properties of periwinkle shell reinforced polymer (epoxy resin) matrix composite

Polymers are very interesting and useful materials that have many applications in various areas of engineering. Composites formed with these materials are known to exhibit outstanding mechanical, electrical, and thermal properties. In this work, a polymer, epoxy resin, was reinforced with a biodegradable material, periwinkle shell (PWS) particles, using the hand lay-up method. The PWS was pulverized using a ball mill and three sieve sizes of the PWS (75, 150, and 300 µm) were sieved out. Various samples of the composite were produced by reinforcing the epoxy resin matrix with 10, 20, 30, 40, and 50 wt% of each of the PWS particle sieve sizes. The samples so formed were subjected to the following mechanical tests: hardness, tensile, compressive, and impact tests. It was found out that the samples of composites showed higher values of the parameters tested for than ordinary epoxy resin showed. In the samples of composites, it was found that the samples with a higher weight percentage of the PWS reinforcement recorded higher values of those mechanical properties tested for. The higher the weight percentage of the PWS in the composite, the greater the value of the mechanical property tested for.

Development of jackfruit (&lt;i&gt;Artocarpus heterophyllus&lt;/i&gt;) bulb and seed flour-based pasta

Jackfruit (<em>Artocarpus heterophyllus</em>) is one of the major edible foodstuffs rich in carbohydrates and fiber. This study investigated the reduction of postharvest losses of jackfruits by value addition. Jack fruit seeds (JFS) flour and Jackfruit bulbs (JFB) flour were used as raw material. JFB and JFS were subjected to mechanical drying, grinding and sieving (particle size &lt;200μm) to yield the JFS flour and JFB flour. The composite flour consists of different ratio of JFS, JFB, and cassava flour (CF), corn flour and semolina. The proximate composition, physical properties and cooking characteristics of developed pasta were determined. Sensory attributes of the pasta were evaluated using Hedonic scale (7-points) with 36 semi-trained panelists. The best composite flour formulation was JFS: JFB: semolina: CF: corn flour, at the ratio of 40:40:10:5:5. Crude protein (13.26±0.18%), crude fiber (4.91±0.61%) and ash (3.35±0.04%) were higher in the best selected composite flour than the other treatments. Carbohydrate content (71.28%) was the lowest in T3 formulation. However, there was no significant difference (p&gt;0.05) in moisture content among the treatments, whereas, hardness and water activity differed significantly (p&lt;0.05) among the treatments. The best selected formulation exhibited higher water absorption (1.20±0.02 g/g) and cooking time (8.6±0.2 min) than the other treatments while cooking loss (13.3±0.4%) was lower than the other treatments except the control. Lightness value of pasta was decreased with increasing the amount of JFS and JFB flour. In conclusion, value added jackfruit flour pasta has a higher potential for commercialization as a convenient food for the consumers with busy lifestyles.

Influence of voxel size for µCT imaging of particles on measurement accuracy

Size and shape of particles have a decisive influence on macroscopic properties of building materials. Capturing µCT images (micro-computed tomography) of these particles enables the determination of three-dimensional size and shape parameters. Here, the influence of the structural resolution on the measurement accuracy is studied. µCT images of single particles are taken with varying structural resolution. The experimental results indicate that scanning particles, resolving the particle sieve size with 12 to 25 voxels, yields an acceptable level of measurement accuracy.

A feasibility study on calcareous soil stabilization using polymers in Barka region.

In the Gulf region most of the soils require soil stabilization to increase soil bearing capacity for construction of safe and sustainable buildings. The soils are stabilized either by physical stabilization, chemical stabilization or by mechanical stabilization. The aim of this project is to stabilize calcareous soil in the Barka region with synthetic polymers. The soil samples from the Barka region collected by using standard soil sampling methods. The synthetic polymer was mixed with the calcareous soil in 1%, 3% and 5%. The soil samples were tested for sieve analysis, Atterberg Limit, Particle Density, Proctor test and California Bearing Ratio test before and after addition of synthetic polymer. It was observed that there is a positive impact on the geotechnical properties of soil with the addition of Polymer. The optimum moisture content of the soil reduced and the maximum dry density of the soil increased. The optimum results were found at 5% addition of polymer where the optimum moisture content was found out to be 12.6% and the maximum dry density was found out to be 1.997 Mg/m3. The Atterberg limit test to show that the plasticity index of the soil reduced with the addition of polymer and the optimum results were found out at 5% addition of polymer. Finally, the CBR test results determine that the soil bearing capacity increases with the addition of Polymer. After the addition of 5% Polymer, the CBR value was found out to be 27.465% compared to 14.19% for the fresh calcareous soil. The results are encouraging.&#x0D; Keywords: Atterberg Limit, Calcareous soil, CBR, polymer, stabilization.

Fine Sieving of Atmospheric Particles in a Collected Air Sample Using Oil Electrophoresis

To solve the challenge of extracting nano- to micrometer-sized atmospheric particles from a mixed sample, we developed an electrostatic sieve system, the Fine Sieving of Collected Atmospheric Particles using Oil Electrophoresis (iSCAPE), based on the application of an electrostatic field to a non-conductive mineral oil. Using atmospheric samples, which were collected from different cities, in addition to soil and road dust samples, we tested this system under different conditions and found that the “iSCAPE’d” particles moved rapidly at varying velocities and in two opposite directions. The diverse origins of the sample—ambient air, soil, or road dust—exhibited specific charged properties, and clearly affected the electrical mobility, as demonstrated by the graphs, of the particles following the “iSCAPEing,” which lasted from seconds to minutes. We also observed an increased abundance of particles in specific mobility ranges. Furthermore, according to our adenosine triphosphate (ATP) monitoring results, the iSCAPE is capable of separating bacterial particles by size and electrical mobility. The experimental data suggests that the iSCAPE relies heavily on the electrostatic field strength, mineral oil viscosity, and run time. In theory, this method can extract any targets from a complex sample, thus creating many research opportunities in environmental, biomedical, and life sciences.