The article presents a method of controlling the size of droplets generated by a system that sprays a high-viscosity liquid containing particles of a solid body, i.e., a catalyst. The work is a ...continuation of previous research concerning the spraying of liquids with a catalyst, which improves the efficiency of the process. As a result of the conducted CFD calculations, it was found that to bring the catalyst to the system, a droplet with a diameter of at least 30 µm should be generated. The tests were carried out on a laboratory scale on a model isopropanol-water system. A polymer containing Raney nickel particles was added to the suspension. The analysis of the obtained data confirmed the possibility of generating droplets with the desired diameters in order for the liquid carrying the catalyst to not evaporate before it is delivered to the combustion chamber. The designed and constructed test system allows the diameters of the generated droplets to be controlled by changing the settings of the spraying nozzle. Moreover, it enables the parameters of the process, and the spraying itself, to be controlled. In further work, tests on a real 0.5 MW facility are planned. Due to the use of a catalyst, a greater degree of fuel burnout can be obtained, and the dynamics of the combustion process can be improved. Additionally, the parameters of the emitted exhaust gases and ash composition can also be enhanced.
Lung surface is the first line of contact between inhaled carbon nanomaterials, CNMs, and the organism, so this is the place where pulmonary health effects begin. The paper analyzes the influence of ...several CNMs (single- and multi-walled nanotubes with various surface area: 90-1,280 m
/g and aspect ratio: 8-3,750) on the surface-active properties of the lung surfactant, LS, model (Survanta). Effects of CNM concentration (0.1-1 mg/ml) and surface oscillation rate were determined using the oscillating drop method at simulated breathing conditions (2-10 s per cycle, 37 °C). Based on the values of apparent elasticity and viscosity of the interfacial region, new parameters: S
and S
were proposed to evaluate potential effect of particles on the LS at various breathing rates. Some of tested CNMs (e.g., COOH- functionalized short nanotubes) significantly influenced the surfactant dynamics, while the other had weaker effects even at high particle concentration. Analysis of changes in S
and S
provides a new way to evaluate of a possible disturbance of the basic functions of LS. The results show that the expected pulmonary effects caused by inhaled CNMs at variable breathing rate depend not only on particle concentration (inhaled dose) but also on their size, structure and surface properties.
•Improvement of deagglomeration of lactose particles in converging nozzles is observed at higher nozzle constriction and increasing airflow rate.•Oscillating airflow helps to break-up particle ...aggregates at low pressure drop.•CFD results explain the mechanism of powder aggregates break-up.•Pressure drop determines the applicability of proposed concepts of drug aerosolization in dry powder inhalers.
Deagglomeration of lactose particles during fluidization by air and the subsequent flow through converging nozzles was evaluated experimentally for constant (Q=5–30dm3/min) and pulsating airflows (Q=10/20dm3/min, f=1.6/4.3Hz). Discussion of observed effects was supported by results of CFD simulations of airflow pattern in the tested systems and calculations of the strain rate distribution. It was demonstrated that the increase of flow acceleration due to nozzle constriction leads to powder disaggregation (particle median size reduction from 5.6 to 3.2μm in the best case) on the cost of higher energy dissipation. The median size of aerosol particles obtained in the analyzed systems was correlated with the logarithm of the pressure drop. It was demonstrated that observed effect of particles deagglomeration relies on the focusing of aerodynamic stresses in the region of aerosol ejection to a stagnant fluid. Airflow pulsations were shown to enhance the break-up of powder aggregates but only in the systems of a low pressure drop. This effect is explained by amplification of particle–fluid interactions by flow unsteadiness. The results of the study were discussed in the perspective of possible application of proposed concepts to improve the performance of passive and active dry powder inhalers (DPIs).
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•Difference in properties of similar nasal drugs influences spraying and deposition.•Inspiratory airflow spreads the deposited drug more distally into the nasal cavity.•The secondary ...transport of nasal drugs depends on their rheological properties.
The study is focused on the analysis of physicochemical properties of selected nasal sprays of mometasone furoate, and the influence of these properties on aerosol quality and penetration in the pediatric nose. After the determination of drugs surface tension and viscosity, spray geometry and size distribution of aerosol droplets, the topical delivery of each drug to different parts of the pediatric model of the nose with the flexible vestibule was evaluated by colorimetric visualization. All tested drugs are pseudo-plastic liquids, showing some differences in flow consistency constant k (range 714–1422) and flow behavior index n (range 0.16–0.31). At no-flow conditions, all sprays are deposited mainly in the anterior of the nasal cavity and the septum (2–3 cm from the nostril), as a result of inertial impaction of large droplets. The deposition range is slightly influenced by the geometry of the aerosol cloud, which, in turn, depends both on drug properties and the type of the spraying nozzle. Deposition experiments accompanied by the airflow show an enhancement of drug transport to deeper parts of the nasal cavity (up 4–6 cm from the vestibule), and this effect can be attributed to the secondary effects of spreading of the deposited liquid layer along the narrow air passages in the nose. Plume geometry, dose volume and rheological properties of the drug were shown to be important factors in the spray penetration pattern in the pediatric nose. The deepest delivery can be expected for drugs of low viscosity and short aerosol plumes.
Background and Aims
Eutypa dieback is an economically important disease of grapevines and a major threat to vineyard longevity throughout the world. Developing effective preventative strategies ...offers the best means of control. In this study, pruning wound protectants and various spray applications were evaluated for their ability to prevent infection by ascospores of Eutypa lata.
Methods and Results
Fungicides and natural alternative treatments were applied by hand to grapevine pruning wounds in winter prior to inoculation with E. lata. In a series of greenhouse and field experiments, tebuconazole, pyraclostrobin, fluazinam, garlic extract and lactoferrin significantly reduced infection. A range of tractor‐driven sprayers was used to apply tebuconazole to pruning wounds, and those which provided good coverage reduced infection by E. lata to a level similar to that when tebuconazole was applied with a paintbrush.
Conclusion
Eutypa dieback can be controlled with several fungicides and natural treatments. Tractor‐driven sprayers, which by design or modification can efficiently deliver maximum possible coverage at high output rates, can be used for application of pruning wound treatments.
Significance of the Study
Results of this study contributed to registration of fungicides for use as pruning wound treatments to control E. lata in Australia. Demonstrating the ability of tractor‐driven sprayers to apply treatments effectively has led to greater industry adoption of dormant treatments and may decrease the future impact of Eutypa dieback.
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•Efficient particle engineering provides DPI formulations with high performance.•DoE approach using spray-drying can contribute to design of DPI formulations.•Numerical simulations ...combined with medical image approaches will be useful.•Combination of experiment and simulation is necessary to individual medicine.
Compared with oral and parenteral formulations, inhaled formulations are attractive because of their great benefit and potential to enhance therapeutic effects of medications. Among the available inhaled formulations, powders used with dry-powder inhalers (DPIs) have become a preferred option because of their many advantages over other inhaled formulations. Additionally, a powder technological approach is required and available for sophisticated design of DPI formulations. To provide appropriate treatment using a DPI formulation, inhaled particles containing drugs should be delivered to the appropriate sites in the lungs of individual patients. It is indispensable that the design of DPI formulations specify particle properties suitable for a specific disease and the appropriate positions in the lungs to which the inhaled particles must be delivered. This article focuses on the current particle technological approach toward designing DPI formulations and numerical simulation analysis of behavior and deposition of inhaled particles in the lungs. As a future perspective from the viewpoint of pharmaceutical particle technology, a combination of experimental and simulation approaches is expected to improve the ability to obtain maximum lung delivery as well as target the site of deposition in the lungs of individual patients.
Inhalation of medicinal aerosols requires the specific properties of powders to assure their de-aggregation to particles within the respirable size. In this study we evaluate the influence of ...additives of pulmonary surfactant (PULMS) components in lactose solution used for preparation of powders by pneumatic atomization and the consecutive spray-drying (SD). It was demonstrated that PULMS in a low concentration (0.1%) changed the morphology of powder particles and improved their aerosolization properties in comparison to spray-dried lactose obtained in similar conditions. The mass median diameter of lactose/PULMS aerosol particles released from a commercial inhaler was reduced to 6.6
μm when compared to the value of 17.2
μm for lactose. At the same time the fraction of particles smaller than 5
μm was increased to 37% (from ca. 7% for lactose). These results were attributed to PULMS adsorption on droplets generated during SD process. Moreover, the particles appeared to be very effective in reducing the dynamic surface tension after dissolution in water what indicates that PULMS components are effectively incorporated into powder particles obtained by SD. This effect not only improves properties of inhalable powder but simultaneously allows to deliver PULMS to the lungs where it can act as an absorption enhancer of inhaled medicines.
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