Dry Particles Research Articles

The interplay between compression mechanisms and compaction pressure in relation to the loss of tabletability of dry granulated particles

The study investigated the sequential relationship between composition, fracture strength, degree of fragmentation, and loss of tabletability (LoT) of dry granulated particles to get a deeper insight into the underlying causes controlling the LoT. Surrogate granules, consistent in dimension and composed of a systematic variation of a brittle (lactose) and plastic powder (microcrystalline cellulose), were prepared by compaction. These granules were then compressed into tablets at low compression pressures, considered to correspond to the compression phase during which the main fragmentation occurs. The mechanically weak tablets were gently deaggregated into compressed granules, and the proportion of formed fragments was determined using dry powder laser diffractometry and by sieving as an indication of the degree of granule fragmentation.The compressed granules comprised three sub-populations of particles, i.e., non-fragmented granules, fragmented granules, and fine particles, with fragmentation ceasing already within the restricted pressure range applied. The degree of granule fragmentation was dependent on composition and showed an inverted relationship with granule fracture strength. For tablets formed at 100 MPa, the LoT was primarily controlled by the degree of fragmentation, while for tablets formed at 300 MPa, the LoT was affected by a combination of granule fragmentation and deformation. Thus, the relative impact of fragmentation and deformation on the LoT is dependent on the tableting pressure.

Thermal analysis and kinetic investigation of using a hybrid adsorption-hydration method to promote CO2 capture

In this work, a hybrid adsorption-hydration method was utilized to promote CO2 capture. The CO2 capture performance in the fixed bed of coal particles was assessed at various water saturations (0 %, 20 %, 40 %, 70 %, and 100 %), 277.15 K, and 3.2 MPa. It was found that gas consumption at 100 % water saturation increased by 45 % compared to that at 0 % water saturation (dry coal particles). Moreover, as the water saturation increased, CO2 capture became dominated by hydrate formation rather than gas adsorption. The thermal analysis for CO2 capture at 0 % and 100 % water saturation detected the exothermic peaks associated with CO2 adsorption and CO2 hydrate formation, as well as the endothermic peaks corresponding to CO2 desorption and CO2 hydrate dissociation. This confirms that CO2 capture in the fixed bed of water-saturated coal particles consists of CO2 adsorption followed by hydrate formation. The morphologies of CO2 hydrate formation in the fixed bed of 100 % water-saturated coal particles were observed, and the mechanism of CO2 capture using the hybrid adsorption-hydration method was illustrated based on the thermal analysis and kinetic investigations. It was also found that after the adsorption-hydration process, the average cumulative pore volume of the coal particles decreased by 14.47 % compared to the original coal particles, and the micropores and mesopores were predominantly affected. Therefore, utilizing the hybrid adsorption-hydration process in a fixed bed of coal particles provides a promising method to enhance CO2 capture.

Mastering Snow Analysis: Enhancing Sampling Techniques and Introducing ACF Extraction Method with Applications in Svalbard.

Semi-volatile organic contaminants (SVOCs) are known for their tendency to evaporate from source regions and undergo atmospheric transport to distant areas. Cold condensation intensifies dry deposition, particle deposition, and scavenging by snow and rain, allowing SVOCs to move from the atmosphere into terrestrial and aquatic ecosystems in alpine and polar regions. However, no standardized methods exist for the sampling, laboratory processing, and instrumental analysis of persistent organic pollutants (POPs) in snow. The lack of reference methods makes these steps highly variable and prone to errors. This study critically reviews the existing literature to highlight the key challenges in the sampling phase, aiming to develop a reliable, consistent, and easily reproducible technique. The goal is to simplify this crucial step of the analysis, allowing data to be shared more effectively through standardized methods, minimizing errors. Additionally, an innovative method for laboratory processing is introduced, which uses activated carbon fibers (ACFs) as adsorbents, streamlining the analysis process. The extraction method is applied to analyze polychlorobiphenyls (PCBs) and chlorinated pesticides (α-HCH, γ-HCH, p,p'-DDE, o,p'-DDT, HCB, and PeCB). The entire procedure, from sampling to instrumental analysis, is subsequently tested on snow samples collected on the Svalbard Islands. To validate the efficiency of the new extraction system, quality control measures based on the EPA methods 1668B and 1699 for aqueous methods are employed. This study presents a new, reliable method that covers both sampling and lab analysis, tailored for detecting POPs in snow.

Intercepting and impact resistance property of dry particle flow by PFC3D-based slit dam

Intercepting and impact resistance property of dry particle flow by PFC3D-based slit dam

A combined experimental-mathematical study on the kinetics of dry ice sublimation under different airflow velocities and blowing modes

The sublimation rate of dry ice, crucial for its cooling performance, is typically influenced by environmental temperature, pressure, and specific surface area. However, the effect of wind speed under forced air convection is not well understood, and current sublimation kinetic models inadequately capture this influence, leading to discrepancies between simulations and experiments. This study examines the sublimation kinetics of static dry ice particles under varying wind speeds and blowing modes. A mathematical model was developed to determine the sublimation kinetic parameters by integrating the Clausius-Clapeyron equation, mass transfer theory, and hybrid particle swarm optimization (HPSO) algorithm. These parameters were then used to create a cooling model for a small insulated box, and the results were validated against experimental data. The findings show that increasing wind speed enhances the sublimation rate of dry ice, with upward-blowing conditions resulting in higher rates than side-blowing conditions. The model’s predictions closely match experimental data, with a maximum mass change deviation of less than 3 % and a maximum temperature deviation of less than 4 °C, demonstrating high reliability.

Electro-responsive superabsorbent hydrogel based on carboxymethyl cellulose as a draw agent for forward osmosis desalination

To explore a simple and energy-efficient approach to regenerate draw agent is a key challenge for forward osmosis (FO) desalination. Electro-responsive hydrogels have attracted great attention due to their reversible swelling-shrinking behaviors under an electric stimulus. However, the developed electro-sensitive hydrogels based on 2-acrylamido-2-methyl-l-propanesulfonic acid (AMPS) so far exhibit low reusability due to their unstable electro-sensitive properties and poor degradability with potential environmental impact. This study explored the use of an electro-responsive superabsorbent hydrogel as a draw agent by grafting acrylic acid (AA) and acrylamide (AM) onto sodium carboxymethyl cellulose (CMC). The grafted hydrogel’s morphology and structure were investigated by FTIR and SEM. The swelling behaviors and deswelling properties in an electrode contact system were examined. The swelling kinetics of the hydrogel could be well described by the Schott's pseudo-second-order model with a theoretical swelling ratio of 452.5 g/g. The grafted hydrogel exhibited stable electro-sensitive characteristics with a decrease of 7.3 % in the equilibrium swelling ratio after undergoing three cycles of deswelling and swelling. During the FO test, the dry hydrogel particles produced a water flux of 1.55 L·m−2·h−1 within the first hour, surpassing the performance of other carboxylic acid-based hydrogels used as draw agents. Significantly, it exhibited encouraging water recovery capabilities in the five recycling FO processes, retaining around 84 % of its initial water recovery ratio after 40 min of exposure to a voltage of 15 V. This indicated that the grafted hydrogel could be considered as an effective and sustainable draw agent for FO desalination.

Robust magnetic vivianite recovery from digested sewage sludge: Evaluating resilience to sludge dry matter and particle size variations

Phosphorus recovery via vivianite extraction from digested sludge has recently gained considerable interest. The separation of vivianite was demonstrated earlier at the pilot scale, and operational parameters were optimized. In this study, we tested the robustness of this technology by changing the sludge characteristics, such as dry matter, and via that, sludge viscosity, and vivianite particle size. It was proven that the main factor influencing recovery was the concentration of vivianite in the feed. The technology can extract vivianite even when the sludge has higher dry matter (1.8% - 3.3%) and, therefore, higher viscosity. Smaller vivianite sizes (< 10 µm) can still be recovered but at a lower rate. This made magnetic separation applicable to a wide range of wastewater treatment plants.

Fabrication of a Hydrophilic Al2O3/AlN EP Coating with Self‐Cleaning and High‐Efficiency Anti‐Corrosion Properties

AbstractCurrently, with the gradual development of anticorrosive coatings, the pursuit of simple preparation methods and the improvement of anticorrosive coatings’ properties have become the major research trends. This study successfully prepared a hydrophilic super anticorrosive coating through a simple mixing method. The coating has a contact Angle of 67.8° and a rolling Angle greater than 20°. This coating can withstand 180 days of salt spray test with no bubble or rust formation when placed on a Q 235 substrate in a 3.5 wt % NaCl solution, demonstrating the excellent corrosion resistance of the AO0.4AN0.6EP coating. Furthermore, after being immersed in a 3.5 wt % NaCl solution for 3 days, the AO0.4AN0.6EP coating exhibited the largest impedance diameter (2.07×108 Ω⋅cm2), almost three times larger than other coatings, and possessed the highest Bode modulus value, one order of magnitude higher than other coatings. After immersion in a 3.5 wt % NaCl solution for 7 days, the AO0.4AN0.6EP coating had the largest Ecorr and the smallest icorr, indicating its superior corrosion resistance. In addition to corrosion resistance, the AO0.4AN0.6EP coating showed no signs of cracking, discoloration, or decomposition after being exposed to ultraviolet aging lights for 30 days, demonstrating its excellent UV resistance. Moreover, neither dry soil particles nor muddy water could adhere to the coating surface, proving its good self‐cleaning ability. Therefore, this coating holds promising applications in the field of super corrosion‐resistant coatings.

Bioaerosol sampling and bioanalysis: Applicability of the next generation impactor for quantifying Legionella pneumophila in droplet aerosols by flow cytometry

Bioaerosol generation, sampling, and cultivation-independent quantification of pathogenic bacteria play a crucial role in studying dose-response effects of Legionella pneumophila. Here, the Next Generation Impactor (NGI), initially created for pharmaceutical inhaling studies, was assessed for its potential to sample airborne bioaerosols and to separate size-dependent wet droplets by incrementally increasing the airflow speed. This stainless-steel sampler was shown in this study to be suitable for sampling prior to cultivation-independent analysis of pathogen-containing bioaerosols using washable cups. The applicability was studied by quantifying the total and intact cell count of L. pneumophila by flow cytometry after being dispersed into a droplet aerosol. Our results demonstrate a high total sampling efficiency of 95.5% ± 11.8% despite a lower biological sampling efficiency of 59.7% ± 16.5% for dry aerosols. However, by elevating the relative humidity (RH) to 100% in a liquid aerosolization unit, the biological sampling efficiency increased to over 90% for L. pneumophila. More than 50% of the cells were found in stage 1 using the liquid aerosolization unit. In comparison, 80% of the cells were sampled in stages 4–6 at 30% RH. Specifically, while at 100% RH, the droplet size mattered, at 30% RH, the size distribution of dry particles, in this case L. pneumophila, was relevant due to evaporation processes, which explains the size differences. These findings indicate the potential of the NGI for further exploration and application in studying other aerosol-borne pathogens, especially concerning the size distribution of wet droplets, viability, or effect-based bioanalysis.

Selection of insulation coatings for industrial-grade FeSiBC amorphous soft magnetic composites based on dry particle coating method

Selection of insulation coatings for industrial-grade FeSiBC amorphous soft magnetic composites based on dry particle coating method

Evaluating the role of amino acids and isothermal dry particle coating in modulating buccal permeation of large molecule drug vancomycin

The formulation and delivery of macromolecules through the oral route pose considerable challenges due to factors such as large molecular weight, pH sensitivity, and limited formulation approaches. This challenge is compounded if the drug is poorly permeable, necessitating innovative drug delivery strategies. Vancomycin, a widely prescribed glycopeptide antibiotic, has an oral bioavailability of less than 10%, leading to predominantly intravenous administration and potential patient discomfort. This study explores the potential of the buccal route as a non-invasive, highly vascularised alternative route of administration, offering a rapid onset of action while bypassing the first-pass metabolism. In this study, vancomycin was coated with L-glutamic acid using an isothermal dry particle coater to modulate permeation through the buccal cell line, TR146. Results confirm significant impact of both amino acid concentration and dry particle coating on the rate and extent of drug permeability. With the introduction of L-glutamic acid and utilisation of the isothermal dry particle coater, vancomycin’s permeation profile increased six-fold compared to the control due to the formation of drug ion-pair complex. Imaging studies showed the presence of layered micronized glutamic acid particles on the surface of dry coated vancomycin particles which confirms the role of dry coating and amino acid concentration in modulating drug permeation. Microbiology experiments in Staphylococcus aureus, minimum inhibitory concentration and biofilm disruption studies, provided confirmatory evidence of antimicrobial activity of dry coated glutamic acid-vancomycin ion pair particulate structure. This study demonstrates, for the first-time, buccal delivery of dry coated large molecule drug, vancomycin, through controlled deposition of amino acid using innovative particle coating strategy.

Modeling the evaporation and drying of two-component slurry droplets

In this paper, we present a mathematical model and numerical simulation for the evaporation and drying of a liquid droplet containing suspended solids, relevant to processes such as spray drying and spray pyrolysis in the food and pharmaceutical industries. The model comprises three stages: first is the evaporation of the liquid droplet consisting of solid particles, followed by the second stage starting with the formation of a porous crust around a wet-core region and, finally, the third stage with sensible heating of the dry particle. Using a finite difference method with a moving grid, we account for the moving interface between the crust and wet core. Our model incorporates spatial temperature variations and is validated against experimental data on colloidal silica droplet drying, showing good agreement. We examine model assumptions and analyze the impact of drying conditions on drying rate and final particle morphology. Along with the temperature and velocity of the drying gas, we also find that the shape of suspended solid particles inside the droplet and assuming continuum flow of vapor through the crust influence drying quality. Finally, we develop a regime map to predict whether the final particle will be solid or hollow based on operating conditions.

Carboxymethyl cellulose-based preformed particle gels for water management in oil and gas reservoirs

Carboxymethyl cellulose (CMC) based materials have been proposed as preformed particle gels (PPGs) for reducing excessive water production in oil and gas reservoirs. Multi-sized dry particles ranging between 100 and 1180 μm have been synthesized using microwave-assisted grafting copolymerization of CMC and acrylamide (AM)/n,n''-methylene-bisacrylamide (MBA). FTIR and SEM confirmed CMC crosslinked polyacrylamide's chemical structure and morphology (CMC/CPAM). Thermo-gravimetric analysis has demonstrated the thermal stability of dry PPGs up to 309 °C. CMC/CPAM showed slightly high absorbency in brine 2 (TDS = 67.3 g/L) compared to brine 1 (TDS = 33.65 g/L), 1% NaCl, and deionized water, with swelling ratios (SR) between 7.1 and 12.9 g/g at room temperature regulated by MBA weight ratio. The effect of particle size, pH, temperature, and aging on SR and mechanical strength was investigated and discussed based on the CMC/CPAM structures. The swollen PPGs showed excellent resistance to temperatures up to 100 °C with a storage modulus of 9 kPa. The particle size was estimated based on salinity, pH, and temperature and controlled between 118 μm and 3 mm at high temperature (100 °C) and high salinity (TDS = 67.3 g/L) conditions to match the need for carbonate reservoirs. Core flooding experiments demonstrated the effective plugging efficiency of the PPG in open fracture models.

Method for generating dry aerosol particles from a solution: the case of fluconazole

Method for generating dry aerosol particles from a solution: the case of fluconazole

Numerical Simulation and Experimental Study of Gas–Solid Two-Phase Spraying of Dry Powder Fire-Extinguishing System Based on Fire-Extinguishing Inspection Robot

In order to solve the problem where the traditional intelligent inspection robot only has a single inspection function, we studied the use of a dry powder (including an ultra-fine dry powder) as a fire-extinguishing medium for the first time. In fire-extinguishing robots, the spray pressure is difficult to control, and there are several other issues. For integrated inspection, an intelligent, nitrogen-driven fire-extinguishing robot using a dry powder in a pressure-controlled spray was developed. On this basis, in order to investigate nitrogen-driven dry powder particle spraying as a gas–solid two-phase mechanism, as well as the flow characteristics and the influence of relevant parameters on the spraying effect, a nitrogen-driven dry powder particle spraying system was established as part of a gas–solid two-phase computational fluid dynamics model. The flow field of the spraying system and the particle motion characteristics were analyzed to explore the micro-mechanisms of the influence of different driving pressures, pipe diameters, and nozzle configurations on the spraying of the dry powder. In order to investigate the macroscopic effect of dry powder spraying where the gas–solid two-phase micro-mechanisms could not be revealed, an experimental platform was set up, and the experiments verified the accuracy of the numerical simulation results. We also investigated the dry powder spraying effect under different driving pressures, pipe diameters, nozzle configurations, and loading ratios. Finally, an orthogonal test was designed based on the results of the single-factor experiments to find the best combination of parameters required to achieve the optimal spraying effect. The research results can provide a theoretical and technical reference for the design and development of nitrogen-driven dry powder spraying systems.

Dry powder inhaler design and particle technology in enhancing Pulmonary drug deposition: challenges and future strategies.

The efficient delivery of drugs from dry powder inhaler (DPI) formulations is associated with the complex interaction between the device design, drug formulations, and patient's inspiratory forces. Several challenges such as limited emitted dose of drugs from the formulation, low and variable deposition of drugs into the deep lungs, are to be resolved for obtaining the efficiency in drug delivery from DPI formulations. The objective of this study is to review the current challenges of inhaled drug delivery technology and find a way to enhance the efficiency of drug delivery from DPIs. Using appropriate keywords and phrases as search terms, evidence was collected from the published articles following SciFinder, Web of Science, PubMed and Google Scholar databases. Successful lung drug delivery from DPIs is very challenging due to the complex anatomy of the lungs and requires an integrated strategy for particle technology, formulation design, device design, and patient inhalation force. New DPIs are still being developed with limited performance and future device design employs computer simulation and engineering technology to overcome the ongoing challenges. Many issues of drug formulation challenges and particle technology are concerning factors associated with drug dispersion from the DPIs into deep lungs. This review article addressed the appropriate design of DPI devices and drug formulations aligned with the patient's inhalation maneuver for efficient delivery of drugs from DPI formulations.

Lung surfactant inhibition and cytotoxicity at the air-liquid interface of dry particle aerosols

Industrial processes generate chemicals that have the potential to be aerosolized and inhaled by workers, thereby posing health risks. Traditional toxicology methods employing animal models cannot keep up with the pace of emerging hazards. Nascent in vitro practices face challenges regarding translatability to the real world. To address this critical gap, this study demonstrated a workflow utilizing aerosol characterization in a more realistic exposure scenario: dry powder aerosolization onto the air-liquid interface of lung cells. This study delves into biophysical aspects of lung function by examining lung surfactant inhibition. A set of particulates, including aluminum, aluminum oxide, carbon nanotubes, diesel particulate matter, and colloidal silica, was selected for investigation. Particles were in the respirable regime, with mean aerodynamic diameters ranging from 111 to 162 nm by number and 369–2884 nm by mass. Carbon nanotubes and colloidal silica were identified as surfactant inhibitors. Aerosol doses reduced cell viability, up to 38%, with the most pronounced effects observed in response to exposure to aluminum and diesel particulate matter. Dry particle exposure at the air-liquid interface shows promise even at low doses, compared with nebulization or inoculation to submerged cultures. Our findings underscore the potential of this innovative approach for assessing the hazards of aerosolized particulates and emerging contaminants, offering a more accurate representation of real-world exposure scenarios.

An Overview on Pulmonary Insulin

Pulmonary insulin as an alternative to intravascular, intramuscular, and subcutaneous insulin administration, non-invasive insulin administration was created and implemented. It enters the lungs' alveoli through an as-yet-unidentified paracellular process, traverses the alveolar wall, and then circulates throughout the bloodstream. Inhaled insulin was divided into two categories based on its mechanism of action: 1. Rapid acting pulmonary insulin, which quickly disintegrates in the alveoli and circulates throughout the bloodstream as fine powder particles; and 2. slow acting pulmonary insulin. Recently, two technologies were developed: pulmosol powder technology, which employs a rapid drying procedure to make insulin particles of the right size and chemical stability, and AIR technology, which is a porous dry particle aerosol technology. Dry powders, liquid aerosols in cartridge-shaped inhalers, passive inhalers, Microprocessor-controlled inhalers, and liquid nebulizers were the various ways that inhaled insulin was delivered. Many studies have been conducted to examine various intrapulmonary delivery methods, and in January 2006, the US Food and Drug Administration authorized exubera, a dry powder passive inhaler, as the first pulmonary inhaled insulin. The pharmacokinetics of inhaled insulin, dosage guidelines, administration tools, benefits and drawbacks, and candidates for inhaled insulin administration are all discussed in this article.

Influence of the Flowing Speed of Transformer Oil Contaminated by Dry Cellulosic Particles on Its Breakdown Characteristics

Influence of the Flowing Speed of Transformer Oil Contaminated by Dry Cellulosic Particles on Its Breakdown Characteristics

Additive Water Uptake of the Mixtures of Urban Atmospheric HULIS and Ammonium Sulfate

AbstractThe hygroscopicity of atmospheric aerosols affect the global climate and human health. However, the hygroscopic behavior of mixtures of inorganic salts and organics in atmospheric aerosols have not been well characterized for ambient complex organic mixtures. Here, the hygroscopic growth of humic‐like substances (HULIS), which represent the complexity of organic aerosol compounds, from urban aerosols and their mixtures with ammonium sulfate were investigated with measurements from a hygroscopicity tandem differential mobility analyzer and model analyses. The Zdanovskii–Stokes–Robinson (ZSR) relationship, which assumes that the water uptake of each component is additive, was examined for the mixtures. The dependence of the hygroscopicity parameters (κ) of the mixtures on the volume fraction of HULIS is generally represented by the ZSR relationship with the deviations of κ on average of 16% (4%–27% in different mixing ratios), and 0.03 (0.02–0.04) on absolute basis. An assumption of asphericity for the dry particles reduced the deviations (14%). Approximations for the surface tension depression by surfactants and surface‐bulk partitioning were predicted to account for the deviations to a small extent. Furthermore, a thermodynamic model for simplified compound systems showed that the non‐ideality of the solutions potentially explained the deviations from the ZSR relationship. The results of this study support the use of the ZSR relationship for organic‒inorganic mixtures as a practical approximation in atmospheric models, provide a guide for the uncertainty associated with this approximation, and suggest directions for future studies.