Collection Of Particles Research Articles

Unraveling the optical shape of snow

The reflection of sunlight off the snow is a major driver of the Earth’s climate. This reflection is governed by the shape and arrangement of ice crystals at the micrometer scale, called snow microstructure. However, snow optical models overlook the complexity of this microstructure by using simple shapes, and mainly spheres. The use of these various shapes leads to large uncertainties in climate modeling, which could reach 1.2 K in global air temperature. Here, we accurately simulate light propagation in three-dimensional images of natural snow at the micrometer scale, revealing the optical shape of snow. This optical shape is neither spherical nor close to the other idealized shapes commonly used in models. Instead, it more closely approximates a collection of convex particles without symmetry. Besides providing a more realistic representation of snow in the visible and near-infrared spectral region (400 to 1400 nm), this breakthrough can be directly used in climate models, reducing by 3 the uncertainties in global air temperature related to the optical shape of snow.

Activation of the Complement and Coagulation Systems in the Small Airways in Asthma

Background: Several studies have shown the importance of the complement and coagulation systems in the pathogenesis of asthma. Objectives: We explored whether we could detect differentially abundant complement and coagulation proteins in the samples obtained from the small airway lining fluid by collection of exhaled particles in patients with asthma and whether these proteins are associated with small airway dysfunction and asthma control. Method: Exhaled particles were obtained from 20 subjects with asthma and 10 healthy controls (HC) with the PExA method and analysed with the SOMAscan proteomics platform. Lung function was assessed by nitrogen multiple breath washout test and spirometry. Results: 53 proteins associated with the complement and coagulation systems were included in the analysis. Nine of those proteins were differentially abundant in subjects with asthma as compared to HC, and C3 was significantly higher in inadequately controlled asthma as compared to well-controlled asthma. Several proteins were associated with physiological tests assessing small airways. Conclusions: The study highlights the role of the local activation of the complement and coagulation systems in the small airway lining fluid in asthma and their association with both asthma control and small airway dysfunction. The findings highlight the potential of complement factors as biomarkers to identify different sub-groups among patients with asthma that could potentially benefit from a therapeutic approach targeting the complement system.

Numerical Study of Half Wavy and Half W-type Collecting Plates on the Characteristics of Electrostatic Precipitators

Many industries rely heavily on ESPs (electrostatic precipitators). They exist primarily as air filters to prevent hazardous particles from entering the environment. Duct-type ESPs are widely used, have a simple design, and rely on corona wires and collecting plates as their primary arrangement. Numerous studies have been conducted to demonstrate that changing the geometrical shape can aid in improving particle collection efficiency. Wavy plates, W-types, and other designs, for example, have shown to improve particle collection efficiency in a positive degree. The goal of this study is to see what happens when two different types of collecting plates are combined and used together. The proposal is to combine half wavy and half W-type collecting plates and examine them with corona wires with circular shapes. As a result, after completing the numerical study and comparing the results, it is clear that the levels of particle collection efficiency for the various particle sizes have increased with this proposed design. Furthermore, six cases are presented with this design, and the results describe the electrical properties and their magnitude distributions. In fact, in all of the cases presented, this type of combination increased particle collection efficiency.

Iridescent Water Droplets Beyond Mie Scattering

AbstractLooking at a cup of hot tea, an observer can see color patterns and granular textures both on the water surface and in the steam. Motivated by this example, we model the appearance of iridescent water droplets. Mie scattering describes the scattering of light waves by individual spherical particles and is the building block for both effects, but we show that other mechanisms must also be considered in order to faithfully reproduce the appearance. Iridescence on the water surface is caused by droplets levitating above the surface, and interference between light scattered by drops and reflected by the water surface, known as Quetelet scattering, is essential to producing the color. We propose a model, new to computer graphics, for rendering this phenomenon, which we validate against photographs. For iridescent steam, we show that variation in droplet size is essential to the characteristic color patterns. We build a droplet growth model and apply it as a post‐processing step to an existing computer graphics fluid simulation to compute collections of particles for rendering. We significantly accelerate the rendering of sparse particles with motion blur by intersecting rays with particle trajectories, blending contributions along viewing rays. Our model reproduces the distinctive color patterns correlated with the steam flow. For both effects, we instantiate individual droplets and render them explicitly, since the granularity of droplets is readily observed in reality, and demonstrate that Mie scattering alone cannot reproduce the visual appearance.

Design and evaluation of a thermal precipitation aerosol electrometer (TPAE)

Abstract. A new aerosol electrometer (AE), the thermal precipitation aerosol electrometer (TPAE), was designed for use with particles of sizes less than 300 nm, and its performance was experimentally evaluated. The TPAE combines the thermal precipitator with a microcurrent measurement circuit board (i.e., pre-amplifier) for measuring the current carried by collected particles. The thermal precipitator is in the disk-to-disk configuration. Heating paste and air cooling were adopted to establish the desired temperature gradient in the precipitation chamber. At a sample flow rate of 0.3 L min−1 and a temperature gradient of 264 K cm−1, the precipitation efficiency of 70 nm particles reaches ∼100 %. The measurement range of the designed aerosol electrometer is ±5×105 fA, and the accuracy is ±2 fA (2500 to 6.25×107 cm−3 using a flow rate of 0.3 L min−1 and assuming that only singly charged particles exist in the sample). During the evaluation process, the electrical performance of the TPAE was first tested using sodium chloride (NaCl) and soot particles previously classified by a differential mobility analyzer (DMA) and compared to the reference. The precipitation performance of the TPAE was then characterized as functions of the temperature gradient, sampling flow rate and particle size. It was shown that the particle collection efficiency of the built-in thermal precipitator is inversely proportional to the sampling flow rate and proportional to the temperature gradient. The effect of particle size on the particle collection efficiency was minor for NaCl particles of sizes between 23 and 200 nm. Unlike that which was observed for the NaCl particles, a slightly positive correlation between the collection efficiency and the mobility size for soot particles (in the size range of 30–160 nm) was observed. This observation might be due to the existence of soot agglomerates. Compared to existing electrometers, the TPAE does not require the use of high-efficiency filters and includes the additional feature of the “soft” collection of particles for offline particle characterization as well as aerosol current measurement.

Determination of the electron temperature in a supersonic jet of a gas-discharge source from current measurements by an insulated probe system

The aim of this work is to substantiate the possibility of using the classical procedure for determining the electron temperature for diagnosing a supersonic jet of a collisionless plasma of a diatomic gas using the current-voltage characteristic of an insulated probe system. The probe system consists of a cylindrical probe and a reference electrode composed of several cylinders, all placed transversely in the plasma flow. The ratio of the current-collecting surface area of the reference electrode to the area of the probe is arbitrary and can be significantly less than required by the theory of a single probe. Based on a previously constructed mathematical model of current collection, which includes the calculation of the equilibrium potential of the reference electrode as a function of the probe bias voltage, a procedure is developed for determining the electron temperature by measuring the probe currents in a jet of a gas-discharge source of a laboratory dissociated plasma. An approximation of the floating potential of the insulated probe system in a strongly nonequilibrium plasma of a gas-discharge source jet is found, which allows one to determine the boundaries of the transition region of the current-voltage characteristic using a priori information on the plasma parameters. A formula is obtained for extrapolating the ion probe current vs. bias potential relationship into the transition region of the current-voltage characteristic. Within the framework of the adopted mathematical model of charged plasma particle collection, a numerical analysis of the method error of the electron temperature determination procedure is performed. Quantitative characteristics of the effect of the insulated probe system geometry on the method error are obtained. A numerical simulation of the effect of the probe current measurement errors showed that, within the framework of the adopted model, the accuracy of determining the electron temperature using the insulated probe system is comparable with the accuracy of measurements with a single cylindrical probe. The results obtained may be used in the diagnostics of a laboratory plasma of a gas-discharge source.

Nanoparticle growth in thermally diffusive sublimation-condensation systems with low vapor pressure solids

Engineered, condensational growth of aerosol particles is a well-established technique incorporated into particle detection and sampling systems. It is typically accomplished through passage of particles through controlled temperature, supersaturated systems with moderate-to-high vapor pressure compounds, which are liquid at room temperature. However, there are instances where it is advantageous to intentionally grow particles with room temperature, low vapor pressure (<10−3 Pa) solid compounds, either as part of particle collection or ionization systems. Sublimation-condensation, though demonstrated previously, is much less examined, particularly for nanoparticle growth. In this study, we examine a thermally diffusive, laminar flow sublimation-condensation system, wherein solid organic powders (all ionization facilitating matrices) are sublimated at moderate temperature (70–130 °C) and subsequent cooling results in vapor supersaturation, promoting growth of particles. The extent of particle growth was characterized via tandem differential mobility analyzer (TDMA) measurements, with 30 nm–200 nm particles. The grown diameter distributions were monitored for three different low vapor pressure organic solids at variable sublimator temperature settings. We found optimized operating conditions enabled particle growth above diameters of 500 nm. Growth experiments with 7 nm protein (transferrin) particles using ferulic acid as the working solid additionally yielded grown particles in excess of 200 nm in diameter. However, we also found heterogeneous growth occurred simultaneously with homogeneous nucleation of the working solid, which could not be avoided if growth to diameters >500 nm was desired. Homogeneously nucleated particles were broadly distributed in size, and generally smaller than the test particles grown by condensation, but still with diameters in excess of 100 nm. While SEM images of grown particles revealed smooth surfaces not indicative of agglomeration with homogeneously nucleated particles, we cannot rule out the contribution to growth of homogeneously nucleated particle coagulation with sampled particles in the growth system. By comparing to numerical simulations, we use TDMA measurements to estimate effective vapor pressures for the tested sublimated solids, assuming growth occurred solely by vapor condensation. Simulations suggest that saturation ratios in excess of 102 are needed for nanoparticle growth.

Testing the Paradigm of Nuclear Many-Body Theory

Nuclear many-body theory is based on the tenet that nuclear systems can be accurately described as collections of point-like particles. This picture, while providing a remarkably accurate explanation of a wealth of measured properties of atomic nuclei, is bound to break down in the high-density regime, in which degrees of freedom other than protons and neutrons are expected to come into play. Valuable information on the validity of the description of dense nuclear matter in terms of nucleons, needed to firmly establish its limit of applicability, can be obtained from electron–nucleus scattering data at large momentum transfer and low energy transfer. The emergence of y-scaling in this kinematic region, unambiguously showing that the beam particles couple to high-momentum nucleons belonging to strongly correlated pairs, indicates that at densities as large as five times nuclear density—typical of the neutron star interior—nuclear matter largely behaves as a collection of nucleons.

Macroscale simulation of particle loading in electrostatically charged filters

Existing studies have shown that particle collection efficiency of a charged filter tends to decrease with particle loading to a certain extent, then increase with further loading. This contrasts with pressure drop which monotonically increases with particle loading. This trend in particle collection efficiency is due to a variety of factors including, but not limited to, neutralization and aerodynamic shielding of the fibers' electrostatic field. The current paper presents a semi-empirical macroscale simulation method to predict the instantaneous pressure drop and particle collection efficiency of an electrostatically charged filter during the early stages of particle loading. The simulations were performed by using ANSYS software enhanced with a series of in-house subroutines. The simulation results are compared with experimental data (for calibration and validation) obtained from testing a bipolarly-charged (55 μC m−2) polypropylene filter exposed to different levels of nanoparticle loadings. The filter media was loaded (both experimentally and computationally) with polydisperse NaCl nanoparticles (count median diameter of 75 nm) having charge values of ±1e. The loaded media were then tested (experimentally and computationally) with NaCl nanoparticles spanning 10 nm–500 nm in electrical mobility diameter (from TSI 3160 filter tester) having a Fuchs charge distribution. In addition, a high-porosity conditional factor was developed for the Kozeny-Carman permeability equation to expand its application to the case of nanoparticle deposits, where the dendrites’ porosity is very high, and aerodynamic slip is expected to occur.

Discrete-element method simulations of the seismic response of tunnels in deep granular deposit

The seismic response of tunnels constructed in a deposit of granular soil of depth greater than 20 m is examined in this paper. Three-dimensional discrete-element method (DEM) simulations were used to model the soil assembly and the tunnel lining. Soil particles were simulated as rigid spherical particles that are allowed to overlap at the contact points. The tunnel lining was modeled as a flexible system using a collection of particles that were glued together using cementitious bonds to mimic the physical properties of an actual tunnel. Free-field boundaries were utilized at the model’s lateral sides to prevent the propagating wave’s reflections back to the domain and enforce the free-field motion. The DEM computational framework was validated using published centrifuge test results. DEM simulation results reveal good agreement with the experimental centrifuge test results when subjected to the same input motion. Further simulations were carried out to investigate the seismic response of the system under different input motion characteristics. The dynamic earth pressure was monitored at certain points on the tunnel lining. It was found that the dynamic earth pressure and tunnel lining forces increased during seismic excitation and the final residual values were, in most cases, considerably larger than the initial static values. The results also showed that the maximum amplification factor, ground settlement and tunnel lining internal forces occurred close to the resonant frequency of the system.

Design, optimization, and evaluation of a wet electrostatic precipitator (ESP) for aerosol collection

In this study, we developed, optimized, and evaluated in lab and field experiments a wet electrostatic precipitator (ESP) for the collection of ambient PM2.5 (particulate matter with aerodynamic diameter <2.5 μm) into ultrapure water by applying an electrostatic charge to the particles. We operated the wet ESP at different flow rates and voltages to identify the optimal operating conditions. According to our experimental measurements, a flow rate of 125 lpm and an applied positive voltage of 11 kV resulted in a lower ozone generation of 133 ppb and a particle collection efficiency exceeding 80–90% in all size ranges. For the field tests, the wet ESP was compared with the versatile aerosol concentration enrichment system (VACES) connected to a BioSampler, a PTFE filter sampler, and an OC/EC analyzer (Sunset Laboratory Inc., USA) as a reference. The chemical analysis results indicated the wet ESP concentrations of metal and trace elements were in very good agreement with those measured by the VACES/BioSampler and PTFE filter sampler. Moreover, our results showed comparable total organic carbon (TOC) concentrations measured by the wet ESP, BioSampler, and OC/EC analyzer, while somewhat lower TOC concentrations were measured by the PTFE filter sampler, possibly due to the limitations of extracting water-insoluble organic carbon (WIOC) from a dry substrate in the latter sampler. The comparable TOC content in the wet ESP and BioSampler samples differs from previous findings that showed higher TOC content in BioSampler samples compared to those collected by dry ESP. The results of the Dithiothreitol (DTT) assay showed comparable DTT activity in the VACES/BioSampler and wet ESP PM samples while slightly lower in the PTFE filter samples. Overall, our results suggest that the wet ESP could be a promising alternative to other conventional sampling methods.

Extraterrestrial dust flux monitoring at Antarctic Vostok station: New collection of extraterrestrial spherules fallen from May to September 2017

AbstractDust particles obtained by filtering fresh snow collected from May to September 2017 in the vicinity of Vostok station in Antarctica were examined using a scanning electron microscope. The collection of dust particles contains 197 spherules ranging from 0.5 to 117 μm in diameter, the most abundant ones (n = 188) by far being iron oxide spherules. Analyses of meteorological and human activity data suggest an extraterrestrial origin of most of the spherical particles. The particle size distribution histogram showed a smooth increase in their number with decreasing size and a dramatic drop at sizes smaller than 3 μm. The number of spherical particles has an uneven distribution over time, with an intense peak in July 27–28, 2017 which correlates by dates with the peak of the Southern Delta Aquariids meteor shower. The size distribution of the particles collected during the same period indicates the presence of a mechanism that accelerates their fall to the Earth. We propose that they are effective centers of condensation of ice crystals in stratospheric clouds. Our data indicate that collection of micrometeorites with sizes of several microns from the fresh snow is possible, opening a new way for sampling micrometeorites, including separate meteor showers.

Rayleigh-Schrödinger Perturbation Theory and Nonadditive Thermodynamics.

Physical chemists reconcile the empirical theory of classical thermodynamics with the quantum nature of matter and energy when they recover thermodynamics from a statistical mechanical treatment of the individual particles' quantized eigenspectrum. The conclusion is that, when systems are very large collections of particles, interactions between adjacent systems are comparatively negligible, resulting in an additive thermodynamic framework where the energy of a composite system AB may be expressed as the sum of the individual energies of subsystems A and B. This powerful theory is consistent with quantum theory, and it accurately describes the macroscopic properties of sufficiently large systems subject to comparatively short-ranged interactions. Nevertheless, classical thermodynamics has its limitations. Its main drawback is the theory's failure to accurately describe systems not sufficiently large for the aforementioned interaction to be neglected. This shortcoming was addressed by the celebrated chemist Terrell L. Hill in the 1960s when he generalized classical thermodynamics by adding a phenomenological energy term to describe systems not captured by the additivity ansatz (i.e., AB ≠ A + B) of classical thermodynamics. Despite its elegance and success, Hill's generalization mostly remained a specialist tool rather than becoming part of the standard chemical thermodynamics corpus. A probable reason is that, in contrast to the classical large-system case, Hill's small-system framework does not reconcile with a thermostatistical treatment of quantum mechanical eigenenergies. In this work we show that, by introducing a temperature-dependent perturbation in the particles' energy spectrum, Hill's generalized framework is in fact recovered with a simple thermostatistical analysis accessible to physical chemists.

Comparison of active and passive methods for atmospheric particulate matter collection: From case study to a useful biomonitoring tool

In this study we conducted air pollution monitoring using three different methods: active monitoring with the use of high volume aerosol sampler and biomonitoring with the use of lichens and spider webs. All of these monitoring tools were exposed to air pollution in Legnica city, a region of Cu-smelting in the SW Poland, which is well known for exceeding the environmental guidelines. Quantitative analysis was carried out for the particles collected by the three selected methods and concentrations of seven selected elements (Zn, Pb, Cu, Cd, Ni, As, Fe) were obtained. Concentrations found in lichens and in spider webs were directly compared and indicated significant differences between them, with higher amounts noted for spider webs. Then, in order to recognize the main pollution sources the principal component analysis was conducted and obtained results were compared. It resulted that spider webs and aerosol sampler, despite different mechanisms of accumulation, show similar sources of pollution – in this case – copper smelter. Additionally, the HYSPLIT trajectories and the correlations between metals in the aerosol samples also confirmed that this is the most probable source of pollution. This study can be considered innovative as these three air pollution monitoring methods were compared, which has never been conducted before, and their comparison gave satisfying results.

Electrostatic Precipitator Design Optimization for the Removal of Aerosol and Airborne Viruses

In the midst of the COVID-19 pandemic, new requirements for clean air supply are introduced for heating, ventilation, and air conditioning (HVAC) systems. One way for HVAC systems to efficiently remove airborne viruses is by filtering them. Unlike disposable filters that require repeated purchases of consumables, the electrostatic precipitator (ESP) is an alternative option without the drawback of reduced dust collection efficiency in high-efficiency particulate air (HEPA) filters due to dust buildup. The majority of viruses have a diameter ranging from 0.1 μm to 5 μm. This study proposed a two-stage ESP, which charged airborne viruses and particles via positive electrode ionization wire and collected them on a collecting plate with high voltage. Numerical simulations were conducted and revealed a continuous decrease in collection efficiencies between 0.1 μm and 0.5 μm, followed by a consistent increase from 0.5 μm to 1 μm. For particles larger than 1 μm, collection efficiencies exceeding 90% were easily achieved with the equipment used in this study. Previous studies have demonstrated that the collection efficiency of suspended particles is influenced by both the ESP voltage and turbulent flow at this stage. To improve the collection efficiency of aerosols ranging from 0.1 μm to 1 μm, this study used a multi-objective genetic algorithm (MOGA) in combination with numerical simulations to obtain the optimal parameter combination of ionization voltage and flow speed. The particle collection performance of the ESP was examined under the Japan Electrical Manufacturers’ Association (JEMA) standards and showed consistent collection performance throughout the experiment. Moreover, after its design was optimized, the precipitator collected aerosols ranging from 0.1 μm to 3 μm, demonstrating an efficiency of over 95%. With such high collection efficiency, the proposed ESP can effectively filter airborne particles as efficiently as an N95 respirator, eliminating the need to wear a mask in a building and preventing the spread of droplet infectious diseases such as COVID-19 (0.08 μm–0.16 μm).

Physico-chemical characterization of indoor settled dust in Children's microenvironments in Ikeja and Ota, Nigeria

Indoor dust is a collection of particles identified as a major reservoir for several emerging indoor chemical pollutants. This study presents indoor dust particles' morphology and elemental composition in eight children's urban and semi-urban microenvironments (A-H) in Nigeria. Samples were collected using a Tesco vacuum cleaner and analyzed with scanning electron microscopy coupled with an energy-dispersive X-ray (SEM-EDX). The morphology results confirm the presence of alumino silicates, mineral particles and flakes, fly ash and soot, and soot aggregates deposited on alumino silicate particles in the sampled microenvironments. These particles may trigger serious health concerns that directly or indirectly affect the overall well-being of children. From the EDX analysis, the trend of elements (w/w %) in the dust particles across the sampled sites was silicon (386) > oxygen (174)> aluminium (114) > carbon (34.5) > iron (28.0) > calcium (16.7) > magnesium (14.2) > sodium (7.92) > potassium (7.58) > phosphorus (2.22) > lead (2.04) > manganese (1.17) > titanium (0.21). Lead (Pb), a toxic and carcinogenic heavy metal, was observed in locations A and B. This is a concern without a safe lead level because of the neurotoxicity effect on children. As a result, further research on the concentrations, bioavailability, and health risk assessment of heavy metals in these sampled locations is recommended. Furthermore, frequent vacuum cleaning, wet moping and adequate ventilation systems will significantly reduce the accumulation of indoor dust–bound metals.

Investigating the Performance of the Compact Particulate Matter Collector for Use in Domestic Water Systems

The concept of the new water treatment system was developed. The system is based on the previously invented technology – Compact Particulate Matter Collector (CPMC). A primary area was defined in which such technology is intended to be used: water treatment in compact flue-gas condensation systems for a low-power wood-fuelled biomass boiler. Such a system is intended for use in domestic conditions. Such a process involves contamination of technical water with a mixture of particulate matter, resulting in suspension. The CPMC aims to divide the suspension into the relevant fractions effectively. A prototype operating based on CPMC technology was built. An experimental plan was developed, and an experimental stand was constructed to determine the prototype’s efficiency. The experimental plan envisaged five different prototype operating modes and two research steps, depending on the degree of prototype modification. Based on the research results, it was concluded that the prototype could operate effectively in the laboratory environment: achievable efficiency is equal on average between 57.84 % and 88.09 % depending on the operating mode (see the diagram below). The result is assessed as positive. TRL 3 has been reached. The next phases of the study would be the integration of the prototype into the relevant compact flue-gas condensation system and the exploration of commercialisation capabilities, which will stimulate TRL increase.

115 Laboratory Performances of the CIP 10 Personal Aerosol Sampler for the Collection of Submicron Particles

Abstract The CIP 10 is a personal aerosol sampler designed to sample conventional dust or specific occupational inorganic or organic substances such as crystalline silica, isocyanates or mycotoxins. It is widespread used, especially in France. Within the CIP10, the rotating cup contains a porous polyurethane foam devoted to the collection of airborne particles and rotates inside its housing at a speed close to 6700 rpm to induce a 7 or 10 L/min sampling airflow, depending on the particle-size selector. Despite several published works regarding its physical performances, no experimental data exist regarding the sampling efficiency for submicron particles. This study aimed to measure the collection efficiency of the CIP 10 for different types of foam (60 or 75 ppi, functionalized or not) and for the three selectors (inhalable, thoracic, respirable). Polydisperse particles with aerodynamic diameters between 20 nm and 10 µm were produced using various generators and different materials (DEHS, glass beads) in a specific test rig. For a given diameter, the collection efficiency was calculated by comparing the number concentrations measured alternatively upstream and downstream of the rotating cup, using APS (TSI 3321) or SMPS (Grimm DMA Vienna Type, CPC 5.403) spectrometers. While collection efficiency was 100% for particles &amp;gt; 3 µm, it progressively decreased to around 50 % and even below 10 % for aerodynamic diameters of 800 mm and 150 nm, respectively. Collection efficiency was unaffected by the type of foam or sampler flow rate used. Bias maps and consequences on workers aerosol exposure assessment will be discussed.

Sorbitol-coated indomethacin and naproxen particles produced by supercritical CO2-assisted spray drying

Co-spraying active pharmaceutical ingredients (APIs) with excipients is a strategy to create excipient matrices containing API particles to address formulation challenges such as the reconstitution of powders into homogeneous suspensions. In this work, indomethacin and naproxen were co-sprayed with/without sorbitol using supercritical CO2-assisted spray drying (SASD), followed by particle collection in a filter paper, and resuspension in an aqueous excipient solution. SASD yielded particles in the range of 0.4–7.6 µm, naproxen crystalline Form 1 particles in an amorphous sorbitol matrix, and a partially crystalline indomethacin-sorbitol mixture. Most naproxen-sorbitol mixtures successfully constituted homogenous microparticle suspensions where sorbitol matrix dissolved upon contact with water releasing naproxen particles, while indomethacin-sorbitol mixtures were not reconstitutable and not studied further. The API-sorbitol interactions were studied in detail by thermal analysis and COSMO-RS modelling. Overall, the work presented herein provides a better understanding of co-spraying of APIs with excipients for the formulation of reconstitutable dried microparticles.

The effect of combining wavy and W-type collecting electrodes on the properties of electrostatic precipitators

Electrostatic precipitators (ESPs) are commonly used in industry to remove hazardous particles from flue gases using corona discharge. The optimization of collecting electrodes and corona wires arrangement has a significant influence on the particle collection. Many researchers are attempting to enhance current models in multiple forms. This study seeks to analyze the new design of collecting plates, which are a mix of wavy and W-type collecting electrodes, and how they affect electrostatic precipitators’ characteristics. The simulation results of electrical characteristics on the particle collecting efficiency, space charge density distribution, and electrical field distribution in the mixed type of collecting plates are presented. To validate this design, the mixed-type findings were evaluated with those obtained from flat plates (FPs). By using the proposed mixed design also improves collecting efficiency compared with FPs’ results.