Aerosol

The Increasing pace of Industrialization throughout the world has brought with It a serious, and ever Increasing threat from air pollution. It Is true that this threat Is being taken seriously, and that many responsible research workers, government advisers and others are working towards Its reduction. But air pollution seems to have something of the nature of a hydra-headed monster: tackle one problem and another immediately grows to take its place. Actions taken sometimes have results that are far from what was envisioned, sometimes even seeming to make the problem worse.

In "The Forgotten Pollution", Roos shows clearly and In an often entertaining way, how many of the "unexpected" side effects of pollution by waste gases and particles can be explained by paying attention to the electrical activity of the atmosphere and the earth.
Using an Instrument, which he has developed the Electrostatic Charged Aerosol Monitor (ECAM), together with other instruments and reference to the literature, much of it dating back to the early days of science, when electrostatics was appreciated as a science more than It Is today, Roos has succeeded In explaining many hitherto "puzzling" phenomena in a clear, simple and intellectually satisfying way.

The countries around the world are dealing with air quality issues for decades due to their mode of production and energy usages. The outbreak of COVID-19 as a pandemic and consequent global economic shutdown, for the first time, provided a base for the real-time experiment of the effect of reduced emissions across the globe in abetting the air pollution issue. The present study dealt with the changes in Aerosol Optical Depth (AOD), a marker of air pollution, because of global economic shutdown due to the coronavirus pandemic. The study considered the countries in south and southeast Asia (SSEA), Europe and the USA for their extended period of lockdown due to coronavirus pandemic. Daily Aerosol Optical Depth (AOD) from Moderate-resolution imaging spectroradiometer (MODIS) and tropospheric column density of NO 2 and SO 2 from Ozone monitoring instrument (OMI) sensors, including meteorological data such as wind speed (WS) and relative humidity (RH) were analyzed during the pre-lockdown (2017-2019) and lockdown periods (2020). The average AOD, NO 2 and SO 2 during the lockdown period were statistically compared with their pre-lockdown average using Wilcoxon-signed-pairedrank test. The accuracy of the MODIS-derived AOD, including the changing pattern of AOD due to lockdown was estimated using AERONET data. The weekly anomaly of AOD, NO 2 and SO 2 was used for analyzing the space-time variation of aerosol load as restrictions were imposed by the concerned countries at the different points of time. Additionally, a random forest-based regression (RF) model was used to examine the effects of meteorological and emission parameters on the spatial variation of AOD. A significant reduction of AOD (− 20%) was obtained for majority of the areas in SSEA, Europe and USA during the lockdown period. Yet, the clusters of increased AOD (30-60%) was obtained in the southeast part of SSEA, the western part of Europe and US regions. NO 2 reductions were measured up to 20-40%, while SO 2 emission increased up to 30% for a majority of areas in these regions. A notable space-time variation was observed in weekly anomaly. We found the evidence of the formation of new particles for causing high AOD under high RH and low WS, aided by the downward vertical wind flow. The RF model showed a distinguishable relative importance of emission and meteorological factors among these regions to account for the spatial variability of AOD. Our findings suggest that the continued lockdown might provide a temporary solution to air pollution; however, to combat persistent air quality issues, it needs switching over to the cleaner mode of production and energy. The findings of this study, thus, advocated for alternative energy policy at the global scale.

The motion of heavy microspheres after their detachment from at surfaces is considered. The microspheres initially are in static contact equilibrium, embedded fully in the viscous sublayer and subjected to a slowly accelerating fully developed turbulent ow. The equations of motion of the microspheres are presented, including surface roughness e ects. The equations are solved numerically for detachment with and without consideration of a burst-sweep event initiating detachment. The microsphere velocity along the surface after detachment is measured using a strobed laser-light sheet and compared to the numerical solutions. Results indicate that the microspheres undergo pure rolling along the surface before possible entrainment and that the sweep plays a role in the detachment process. A model for predicting the microsphere velocity along the surface after detachment is presented. ?

Antibiotic-resistant bacterial infections have renewed interest in finding substitute methods of treatment. The purpose of the present in vitro study was to investigate the possibility of respiratory delivery of a Burkholderia cepacia complex (BCC) bacteriophage by nebulized aerosol administration. Bacteriophages in isotonic saline were aerosolized with Pari LC star and eFlow nebulizers, at titers with mean value (standard deviation) of 2.15 ϫ 10 8 (1.63 ϫ 10 8 ) plaque-forming unit (PFU)/mL in 2.5-mL nebulizer fills. The breathing pattern of an adult was simulated using a pulmonary waveform generator. During breath simulation, the size distributions of the nebulized aerosol were measured using phase doppler anemometry (PDA). Efficiency of nebulizer delivery was subsequently determined by collection of aerosol on low resistance filters and measurement of bacteriophage titers. These filter titers were used as input data to a mathematical lung deposition model to predict regional deposition of bacteriophages in the lung and initial bacteriophage titers in the liquid surface layer of each conducting airway generation. The results suggest that BCC bacteriophages can be nebulized successfully within a reasonable delivery time and predicted titers in the lung indicate that this method may hold potential for treatment of bacterial lung infections common among cystic fibrosis patients.

The dispersion of heavier-than-air aerosol clouds is of great relevance to the analysis and assessment of hazards in the chemical and petrochemical industries. There are many simple mathematical models for heavy gas dispersion but, in most cases, two-phase dynamics are either ignored or treated in a very simple way, without any convincing scientific justification. In fact almost all of those models which do treat two-phase phenomena rely on the "homogeneous equilibrium" assumption, whether they be for jet dispersion, for gravity dominated dispersion, or for any other aspect of a two-phase release. Here we test the homogeneous equilibrium model against a more sophisticated aerosol approach, in the context of two-phase ammonia clouds released in dry and moist air. It is shown that the simpler model does indeed provide a good description for some envisaged release situations, and guidance is given on where the homogeneous equilibrium model is not likely to be adequate. The homogeneous equilibrium model seems to be adequate for evaluating the dispersion of heavier-than-air clouds containing droplets smaller than 100 ~m.

Comparative analysis of salmeterol xinafoate (SX) powders was carried out to define the aerodynamic properties and mechanism of particle dispersion relevant to the use of these materials in dry powder inhalation drug delivery. Particle sizing methodology was evaluated using laser diffraction, time-of-flight and Andersen cascade impactor measurements combined with electron microscopy and surface area determination. Particle interactions, assessed on the basis of powder bulk density and inverse gas chromatography surface energy measurements, were compared with the aerodynamic forces generated by a dry-powder dispersion device. The supercritically produced material showed by a factor of seven reduced tensile strength of the aggregates and indicated a two-fold increase of fine particle fraction deposited in a cascade impactor when blended with lactose. This effect was explained by the reduced particle aggregation at low differential air pressures and flow rates. A relatively small value of aerodynamic stress required to disperse supercritically produced particles in comparison to micronized material comes from: (a) lower bulk density (loose aggregate structure), (b) larger volume mean diameter, (c) larger aerodynamic shape factor and (d) smaller specific free energy of S-SX particles, in this order of priority. It is shown that aggregation between primary drug particles is important for SX/lactose formulations because such aggregates survive the pre-separation impactor stage.

The ability to atomize a liquid sample into femtoliter droplets and deposit them precisely on a surface is a key problem in microfluidics and chemical analysis. Here we show that control of stable oscillations in an unforced electrospray is a high accuracy drop-on-demand method of depositing femtoliter droplets. Examples are presented of a liquid jet, formed for 35 s, in a discontinuous spray mode controlled using electrostatic fields of short duration; no liquid pump was employed. Each transient jet ejects femtoliter volumes of material, which was deposited on a nearby surface. The volumes ejected by pulsating sprays on a range of nozzle sizes are predicted from electrospray scaling laws. Using the modified nanoelectrospray method, we have printed 1.4 m wide features onto a surface in a drop-on-demand fashion with a placement accuracy of a few micrometers. We anticipate that our technique could produce biological microarrays and precisely deliver ultra-small samples for lab-on-a-chip analysis. ᭧

Aerosols consist of two phases: the solid or liquid particles and the gas in which they are suspended. Most of this book deals with the properties and behavior of the aerosol particles, but the suspending gas interacts directly with the particles and has a great effect on their behavior. Particle motion is resisted by the gas, and the nature of this resistance changes with particle size, especially as particle size approaches the spacing between the gas molecules. Aerosol particles share energy with gas molecules and exhibit Brownian motion. Temperature gradients in a gas create a force on an aerosol particle called the thermophoretic force. Because of the varied interactions between a particle and the surrounding gas, we review the properties of gases-particularly, the kinetic theory of gases-before dealing with the properties of aerosols. 2.1 KINETIC THEORY OF GASES To understand the interactions between particles and the suspending gas, it is necessary to consider certain aspects of the kinetic theory of gases. These interactions are described well by the classical kinetic theory of gases, and it is not necessary to consider the more advanced kinctic thcory and quantum mcchanics to get a physical picture of the interactions that is adequate for the study of aerosol properties. According to kinetic theory, the temperature, pressure, mean free path, and viscosity of a gas are manifestations of the motion of the gas molecules. As will be shown, temperature is a measure of the kinetic energy of the molecules, pressure comes from the force of molecular impacts on the container walls, viscosity represents the transfer of momentum by molecular motion, and diffusion is the transfer of molecular mass. The basic assumptions of the kinetic theory are that (I) gases contain a large number of molecules, (2) the molecules are small compared with the distances between them, and (3) the molecules are rigid spheres traveling in straight lines between clastic collisions. Molecules lead a simple, but happy, life in which collisions with other entities arc their only means of expression. Kinetic theory uses this "bil-liard ball" model of gas molecules to describe properties such as temperature, pressure , viscosity, mean free path, diffusion, and thennal conductivity in tenns of the properties of the billiard balls-that is, the number per unit volume 11, mass 171, diameter d m , and velocity c.

The microscopic particles that float in the air are of many kinds: resuspended soil particles, smoke from power generation, photochemically formed particles, salt particles formed from ocean spray  and atmospheric clouds of water droplets or ice particles. However nowadays we have to add the particles coming from large scale forest fires, fires in chemical plants, continuous heavy fog situations, nitrate deposition, and last but not least the COP19 Corona virus outbreak. The combination of these airborne particles and the gas in which they are suspended are called AEROSOLS. Listening to the tsunami of contradictory advises in the case of the virus makes clear that the know how on aerosols is poor or non existent. Therefore the standard book on AEROSOL TECHNOLOGY of Mr. Hinds is proposed here as Teaching Document. It contains highly useful information for all those who never had thought that these virus particles also goes  upwards, that they are able to change their shape in milliseconds from an invisible particle to a fog sized drop. So if you want to understand better how a virus gets into the air, how it is transported there, how it can be killed, but also how it is able to pass masks and filters, how it can be controlled by electrostatics before it is able to reach you through contact or by air. Therefore the governmental instructions: Wash your hands and keep a safety distance with others.

A new model has been developed to predict the clogging behaviour of high-efficiency particulate air filters. The model takes into account the heterogeneous deposit of particles inside the filter medium. The filter is considered to be a series of elementary slices which are assumed to be homogeneously loaded by aerosol. Particles are assumed to form dendrites which can be considered as newly formed fibres. For each time increment and for each slice, particle collection efficiency of initial and new fibres is calculated according to the Payet model in order to give an overall prediction of the mass of aerosol deposited and the pressure drop. Model results are compared with experimental results.

Aerosols consist of two phases: the solid or liquid particles and the gas in which they are suspended. Most of this book deals with the properties and behavior of the aerosol particles, but the suspending gas interacts directly with the particles and has a great effect on their behavior. Particle motion is resisted by the gas, and the nature of this resistance changes with particle size, especially as particle size approaches the spacing between the gas molecules. Aerosol particles share energy with gas molecules and exhibit Brownian motion. Temperature gradients in a gas create a force on an aerosol particle called the thermophoretic force. Because of the varied interactions between a particle and the surrounding gas, we review the properties of gases-particularly, the kinetic theory of gases-before dealing with the properties of aerosols. 2.1 KINETIC THEORY OF GASES To understand the interactions between particles and the suspending gas, it is necessary to consider certain aspects of the kinetic theory of gases. These interactions are described well by the classical kinetic theory of gases, and it is not necessary to consider the more advanced kinctic thcory and quantum mcchanics to get a physical picture of the interactions that is adequate for the study of aerosol properties. According to kinetic theory, the temperature, pressure, mean free path, and viscosity of a gas are manifestations of the motion of the gas molecules. As will be shown, temperature is a measure of the kinetic energy of the molecules, pressure comes from the force of molecular impacts on the container walls, viscosity represents the transfer of momentum by molecular motion, and diffusion is the transfer of molecular mass. The basic assumptions of the kinetic theory are that (I) gases contain a large number of molecules, (2) the molecules are small compared with the distances between them, and (3) the molecules are rigid spheres traveling in straight lines between clastic collisions. Molecules lead a simple, but happy, life in which collisions with other entities arc their only means of expression. Kinetic theory uses this "bil-liard ball" model of gas molecules to describe properties such as temperature, pressure , viscosity, mean free path, diffusion, and thennal conductivity in tenns of the properties of the billiard balls-that is, the number per unit volume 11, mass 171, diameter d m , and velocity c.

Noninvasive ventilation [NIV] is used extensively in acute and chronic settings, at home, and in hospitals. It plays a pivotal role in managing respiratory failure during the COVID-19 pandemic with robust use in hospitals to avert the need for intubation as well as re-intubation. However, its use is associated with aerosol generation, which poses an immediate threat to all who work around it, like healthcare workers. Besides, domiciliary use is also associated with the same risk to the household and caregivers. Therefore, we need to plan the therapy and forge guidelines and recommendations to keep NIV safe during infections. Here we have reviewed the available literature and applied our experience to formulate guidelines and recommendations. However, updates and appraisals are evolving rapidly, and we need to keep our eyes open to tailor our approach.

This study aims to investigate quantitatively the direct correlation between the mechanical strength of powder agglomerates and their dispersion into aerosols by a dry powder inhaler. Agglomerates of mannitol as a model drug-only formulation were prepared by a rolling method followed by exposure to various relative humidity (RH: 55%, 82%, 86% and 90%). The agglomerate strength was obtained from the compression of single agglomerates at a selected speed rate using an Instron testing machine. The dispersion performance (FPF Loaded ) was determined at flow rates of 60 and 100 l min À 1 using an Aeroliser s coupled to a multistage liquid impinger. Results showed an inverse linear relationship between the agglomerate strength and the dispersion performance. An increase in strength from 3 to 183 kPa resulted in a significant drop (P o 0.05) of 18% in the FPF Loaded . Agglomerates containing 'solid bridges' exhibited higher strength (three to eight times) and lower FPF (5-15%, corresponding to 86% and 90% RH) compared to those containing 'liquid bridges'. These results have provided direct information on the agglomerate strength and its quantitative relationship with powder aerosol performance.

Using a hood for aerosol delivery to infants was found to be effective and user-friendly compared to the commonly used face mask. The currently available hood design has an even greater potential in terms of efficiency, and a numerical simulation can serve as a tool for its optimization. The present study describes the development and utilization of a numerical simulation for studying the transport and fate of the aerosol particles and the carrier gas within a three-dimensional realistic representation of the hood and the infant's head. The study further incorporates realistic breathing patterns, with a longer expiration phase than an inspiration phase. Both nose and mouth breathing are simulated. While the base case assumes that the funnel that delivers the aerosol within the hood is perpendicular to the infant's face, more realistic scenarios include a funnel that is slanted with respect to the infant face, the infant's head taking a general position with respect to the funnel, and the funnel and the head being both tilted. A good agreement is found between computation and experimental results. As expected, the most efficient drug delivery, 18%, is achieved when the funnel is normal to the infant's face. The quantitative evaluation of different scenarios presented in this work increases the knowledge of physicians, nurses, and parents regarding the efficacy of the treatment, in terms of the actual amount of drug inhaled under various modes of function of the device.

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a component of a program designed to add total inward leakage (TIL) requirements for all respirators to Title 42 Code of Federal Regulations Part 84. Specifically, NIOSH undertook a validation study to evaluate the reproducibility of the TIL test procedure between two laboratories. A PortaCount® was used to measure the TIL of five N95 model filtering facepiece respirators (FFRs) on test subjects in two different laboratories. Concurrently, filter efficiency for four of the five N95 FFR models was measured using laboratory aerosol as well as polydisperse NaCl aerosol employed for NIOSH particulate respirator certification. Results showed that two N95 models passed the TIL tests at a rate of ~80-85% and ~86-94% in the two laboratories, respectively. However, the TIL passing rate for the other three N95 models was 0-5.7% in both laboratories combined. Good agreement (≥83%) of the TIL data between the two laboratories was obtained. The three models that had relatively lower filter efficiency for laboratory aerosol as well as for NaCl aerosol showed relatively low TIL passing rates in both laboratories. Of the four models tested for penetration, one model with relatively higher efficiency showed a higher passing rate for TIL tests in both laboratories indicating that filter efficiency might influence TIL. Further studies are needed to better understand the implications of the data in the workplace.

The inlet sampling characteristics of several commercial bioaerosol samplers operating in indoor and outdoor environments have been analyzed by use of available and newly developed equations for sampling efficiency. With a focus on the physical aspects of sampling efficiency, the aspiration and transmission efficiencies have been calculated for the bioaerosol particle size range 1-30 #m, which represents single bacteria, bacteria aggregates, bacteria carrying particles, fungal spores, yeast, and pollen. Under certain sampling conditions, the bioaerosol concentration was found to be significantly over-or underestimated. At wind velocities between 0 and 500 cm s-1, calculations show that the AGI-30 would sample 1-10/zm particles with an inlet sampling efficiency of 20-100%. The entrance efficiency of the 6-stage Andersen viable sampler is 90-150% when sampling isoaxially with respect to horizontal aerosol flows, and 8-100% when oriented vertically at a right angle to the horizontal aerosol flow. For the Burkard portable air sampler, an even wider range of deviation may occur. The bioaerosol samplers used for large particles such as pollen are even less accurate: e.g. 10 times the ambient concentration of Lycopodium spores has been calculated to be aspirated by the Lanzoni sampler when operated at 0.5 I min-1 facing the wind at wind velocity of about 500 cm s-1.

The morphological and dynamic properties of fractal-like particles produced from the combustion of wood are studied in this work. Particles with electrical mobility diameters of 200, 275, 350 and 450 nm were deposited on filters and imaged using a high-resolution scanning electron microscope (SEM). The soot particles consisted of aggregated primary spheres with mean radius a p = 25.5 ± 3.5 nm and standard deviation g = 1.27 ± 0.09. The fractal dimension of the aggregates, D f , was derived from three techniques: (1) D f = 1.84 ± 0.05 from the projected surfaces in the SEM images;

The California Air Resources Board (CARB) and the Joint Research Center of the European Commission (JRC) have collaborated on emissions testing of a light duty diesel vehicle, which is Euro 4 compliant and comes equipped with a diesel particulate filter (DPF). The California testing included an investigation of the regeneration of the DPF over cruise conditions and NEDC test cycles. DPF regeneration is caused by the buildup of soot in the filter, and for the present test vehicle the regeneration process is assisted by a fuel borne catalyst. Regulated exhaust emissions increased substantially during the regeneration events; however, PM emissions levels were below California LEVII emissions standards. There was a very large increase of volatile particles between 5 and 10 nm, and these volatile particles were generated during all of the observed regeneration events. It appears that the particle number instruments that use the PMP methodology do not capture the PM mass increase during DPF regeneration; however, for one regeneration event there was an apparent large increase in solid particles below the PMP size limit. The PM mass increase associated with regeneration appears to be due to semi-volatile particles collected on filters. During the testing, the regeneration events exhibited considerable variations in the time for regeneration as well as the amount of PM emissions. From this investigation, several questions have been posed concerning the emission of very small ( o 20 nm) volatile and solid particles during DPF regeneration that need further investigation.

In April 2010 a workshop on the ''Role of Pharmacokinetics in Establishing Bioequivalence for Orally Inhaled Drug Products'' was sponsored by the Product Quality Research Institute (PQRI) in coordination with Respiratory Drug Delivery (RDD) 2010. The objective of the workshop was to evaluate the current state of knowledge and identify gaps in information relating to the potential use of pharmacokinetics (PK) as the key indicator of in vivo bioequivalence (BE) of locally acting orally inhaled products (OIPs). In addition, the strengths and limitations of the PK approach to detect differences in product performance compared with in vitro and pharmacodynamic (PD)/clinical/therapeutic equivalence (TE) studies were discussed. The workshop discussed the relationship between PK and lung deposition, in vitro assessment, and PD studies and examined potential PK study designs that could serve as pivotal BE studies. It has been recognized that the sensitivity to detect differences in product performance generally decreases as one moves from in vitro testing to PD measurements. The greatest challenge in the use of PD measurements with some OIPs (particularly inhaled corticosteroids) is the demonstration of a dose-response relationship (for local effects), without which the bioassay, and hence a PD study, may not have sufficient sensitivity to detect differences in product performance. European authorities allow demonstration of in vivo BE of OIPs based solely on pharmacokinetic studies. This workshop demonstrated broader interest among discipline experts and regulators to explore approaches for the use of PK data as

Com vista a estudar a deposição sobre a ilha Terceira -Açores, no período de 1 de Março a 16 de Março de 2009, de poeiras oriundas do Saara, recorreu-se a imagens da sonda TOMS-Nimbus (Total Ozone Mapping Spectrometer), que avalia as propriedades ópticas das poeiras em suspensão na atmosfera, e a partir dessas imagens diárias, construi-se uma animação com as mesmas, de modo a verificar a intensidade e duração do evento.

15 Reducing exposure to atmospheric nanoparticles in urban areas is important for 16 protecting public health. Developing new or improving the capabilities of existing 17 dispersion models will help to design effective mitigation strategies for nanoparticle 18 rich environments. The aims of this review are to summarise current practices of 19 nanoparticle dispersion modelling at five local scales (i.e. vehicle wake, street 20 canyons, neighbourhood, city and road tunnels), together with highlighting associated 21 challenges, research gaps and priorities. The review begins with a synthesis of 22

Bronchodilators are frequently used in ICU patients, and are the most common medications administered by inhalation during mechanical ventilation. The amount of bronchodilator that deposits at its site of action depends on the amount of drug, inhaled mass, deposited mass, and particle size distribution. Mechanical ventilation challenges both inhaled mass and lung deposition by specific features, such as a ventilatory circuit, an endotracheal tube, and ventilator settings. Comprehensive in vitro studies have shown that an endotracheal tube is not as significant a barrier for the drug to travel as anticipated. Key variables of drug deposition are attachments of the inhalation device in the inspiratory line 10 to 30 cm to the endotracheal tube, use of chamber with metered-dose inhaler, dry air, high tidal volume, low respiratory frequency, and low inspiratory flow, which can increase the drug deposition. In vivo studies showed that a reduction by roughly 15% of the respiratory resistance was achieved with inhaled bronchodilators during invasive mechanical ventilation. The role of ventilatory settings is not as clear in vivo, and primary factors for optimal delivery and physiologic effects were medication dose and device location. Nebulizers and pressurized metered-dose inhalers can equally achieve physiologic end points. The effects of bronchodilators should be carefully evaluated, which can easily be done with the interrupter technique. With the noninvasive ventilation, the data regarding drug delivery and physiologic effects are still limited. With the bilevel ventilators the inhalation device should be located between the leak port and face mask. Further studies should investigate the effects of inhaled bronchodilators on patient outcome and methods to optimize delivery of inhaled bronchodilators during noninvasive ventilation.

This March 2009 Workshop Summary Report was sponsored by Product Quality Research Institute (PQRI) based on a proposal by the Inhalation and Nasal Technology Focus Group (INTFG) of the American Association of Pharmaceutical Scientists (AAPS). Participants from the pharmaceutical industry, academia and regulatory bodies from the United States, Europe, India, and Brazil attended the workshop with the objective of presenting, reviewing, and discussing recommendations for demonstrating bioequivalence (BE) that may be considered in the development of orally inhaled drug products and regulatory guidances for new drug applications (NDAs), abbreviated NDAs (ANDAs), and postapproval changes. The workshop addressed areas related to in vitro approaches to demonstrating BE, biomarker strategies, imaging techniques, in vivo approaches to establishing local delivery equivalence and device design similarity. The workshop presented material that provided a baseline for the current understanding of orally inhaled drug products (OIPs) and identified gaps in knowledge and consensus that, if answered, might allow the design of a robust, streamlined method for the BE assessment of locally acting inhalation drugs. These included the following: (1) cascade impactor (CI) studies are not a good predictor of the pulmonary dose; more detailed studies on in vitro=in vivo correlations (e.g., suitability of CI studies for assessing differences in the regional deposition) are needed; (2) there is a lack of consensus on the appropriate statistical methods for assessing in vitro results; (3) fully validated and standardized imaging methods, while capable of providing information on pulmonary dose and regional deposition, might not be applicable to the BE of inhaled products mainly due to the problems of having access to radiolabeled innovator product; (4) if alternatives to current methods for establishing local delivery BE of OIPs cannot be established, biomarkers (pharmacodynamic or clinical endpoints) with a sufficiently steep dose-response need to be identified and validated for all relevant drug classes; and (5) the utility of pharmacokinetic studies for evaluating ''local pulmonary delivery'' equivalence deserves more attention. A summary of action items for seminars and working groups to address these topics in the future is also presented. 25

Background: Exhaled breath condensate (EBC) allows non-invasive monitoring of inflammation in the lung. Activation of inflammatory cells results in an increased production of reactive oxygen species, leading to the formation of hydrogen peroxide (H 2 O 2 ). In addition cigarette smoking causes an influx of inflammatory cells and higher levels of H 2 O 2 have been found in EBC of smokers. However there are still unresolved issues reflected by large variations in exhaled H 2 O 2 and uncertainties about the origin of H 2 O 2 release in the lung.

Extreme ultraviolet lithography (EUVL) is considered as the next generation lithography for 32-nm-node or smaller in semiconductor manufacturing. One of the challenges is to protect the EUVL masks against particle contamination, due to the unavailability of conventional pellicles. In this study, the EUVL mask protection schemes of Asbach et al. (2006. Technical note: Concepts for protection of EUVL masks from particle contamination. Journal of Nanoparticle Research, 8,[705][706][707][708], who proposed to mount the mask upside-down, have a cover plate with particle trap and apply phoretic forces, were evaluated against top-down aerosol at atmospheric pressure. Experimental evaluation was performed using 150 mm wafers as witness plates, and PSL particles ranging from 125 to 700 nm. For the numerical assessment of the protection schemes against particles between 10 and 3000 nm, a statistical method using a Lagrangian particle tracking simulation tool was employed to calculate the deposition velocity. It was shown that the critical surface could effectively be protected against top-down aerosol. ᭧

Zinc sul"de particles 20}40 nm in diameter were prepared by electrically driven spray pyrolysis. Solutions of ethyl alcohol with zinc nitrate (Zn(NO ) ) and thiourea (SC(NH ) ) at concentrations from 0.0025 to 0.2 mol l\ and electrical conductivities between 10\ and 10\ S m\ were electrosprayed from steady cone-jets at #ow rates from 0.05 to 0.16 ml h\, with positive and negative polarity. The initially highly charged drops formed were neutralized by bipolar ions from a radioactive source to increase the overall transmission e$ciency through a reactor furnace. This process was made particularly e!ective by the innovation of placing the ion source directly within the electrospray chamber. The diameters of the "nal ZnS particles were measured on-line by a di!erential mobility analyzer and a condensation nucleus counter. In spite of ambiguities in the #ow rate of liquid through the cone}jet (associated to solvent evaporation from the meniscus), these diameters agree approximately with values expected from available scaling laws. Transmission electron micrographs also con"rmed these results. Electrospray pyrolysis is hence able to generate non-agglomerated and spherical ZnS nanoparticles with geometrical standard deviation of about 1.3. 1999 Elsevier Science Ltd. All rights reserved 124 I. W. Lenggoro et al.

The air-jet and ball-mill are frequently used in fine micronization of active pharmaceutical ingredients to the order of 1-5 microm, which is important for increasing dissolution rates, and also for pulmonary delivery. In this study, we investigated the ability of air-jet and ball-mill to achieve adequate micronization on the lab scale using a model soft material, Pluronic F-68. Material mechanical properties were characterized using the nanometer 600. Pluronic F-68 was ball-milled in a micro-mill at different material weights and durations in liquid nitrogen vapor. In comparison, a lab scale air-jet mill was used at various milling parameters according to a full factorial design, where the response factors were particle yield and particle size distribution, which was analyzed using laser diffraction and scanning electron microscopy. The yield achieved with the micro-ball mill was 100% but was ~80% for the air-jet mill, which reduced the size of Pluronic F-68 from 70 microm to sizes ranging between 23-39 microm median diameters. Ball milling produced particles less than 10 microm after 15 min. Although air-jet milling proved capable of particle size reduction of the relatively soft material Pluronic F-68, limitations to the lower size range achievable were observed. The feed rate of the material into the air jet mill was a significant factor and slower feed rates lead to smaller sizes by allowing more time for particle collisions and subsequent particle breakage to occur. Micro-ball milling under cold condition was more successful at achieving a lower range particle size reduction of soft materials.

This article may be openly shared  because it is the work created by US government employee, and is considered to be in public domain according to an agreement between Elsevier and the US government. The US government is the copyright owner. The abstract follows: …. A prototype analyzer for the direct LIBS analysis of nebulized liquid samples was developed and tested, particularly for the analysis of petroleum, organic solvents and aqueous solutions. The LIBS analyzer requires about 750 μl of liquid sample, 1 l of N 2 gas, and 10 s of the analysis time to record 100 spectra. The limits of detection in oil and solvent are as low as 0.01-0.04 ppm for Li, Mg, and Cu. They increase for the difficult elements, such as Pb and Hg (7-10 ppm), Cl (250 ppm), and S (~0.7%). The relative standard deviation of measuring 100 ppm vanadium in oil and solvent was 1.5%. The LIBS detection limits and repeatability are better than required by the standard method ASTM D5185 for the analysis of lubricating oils in ICP-OES. Several petroleum samples were analyzed by LIBS and the quantitative results for V, Ni, and Fe compared to the ICP-OES data. Light crude oils can be nebulized and analyzed directly. Medium crude oils may require minimal dilution at least 1:1, otherwise errors of determination may become large. Presumably, utilization of the internal standard and chemometrics can be useful to correct for the matrix effects. In addition to the trace element analysis, the LIBS prototype demonstrated ability to measure the hydrogen-to-carbon ratio in organic liquid samples. Several unidentified features were observed in the carbon spectrum. Their possible origin is discussed. ☆ This article is published in a special honor issue dedicated to Richard E. Russo to commemorate his 70th. birthday, for his achievements in the fields of laser-material interaction, plasma modeling and evolution, surface analysis with lasers, and for his vision of what is needed and critical in future theoretical, instrumental and methodological development.

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transport of the smoke particles frorn Amazonia was simulated for the period from
August 20 to 29,1995. During tÌris period the air mass iocated below 2 km movecl
to ihe south and carried the smoke particles until 30"S.

Aerosol output, aerosol output rate, and aerosol size distribution are influenced by the compressed air flow rate through the nebulizer cup. Testing a nebulizer-compressor with a drug for inhalation in cystic fibrosis (CF) patients is mandatory prior to starting therapy. Tobramycin solution for inhalation (TSI), TOBI ® , is licensed in Europe with a recommendation for a "suitable" compressor connected to the PARI LC Plus ® nebulizer. To select a compressor, five devices were tested in a previous in vitro study and this resulted in a subsequent in vivo study. Two compressors [CR60 ® and PortaNeb ® (PN)] were compared in an open, randomized, crossover single dose pilot study in 10 CF patients to assess the most suitable device for inhalation of a tobramycin solution (TSI), TOBI ® , with the PARI LC Plus ® nebulizer. Lung function (FEV 1 and FVC), pharmacokinetics [PK; safety (C max , C trough )], lung deposition (indirect method AUC 0-6 ), nebulization time, and patients' experiences (questionnaire) were determined and compared. It was found that values of C max and AUC 0-6 were higher with the CR60 ® than with the PortaNeb ® : 0.70 versus 0.54 mg/L, p ‫؍‬ 0.005, and 2.54 versus 2.01 h.mg/L, p ‫؍‬ 0.017, respectively. T max after use of the CR60 ® appeared earlier (0.64 vs. 0.85 h, p ‫؍‬ 0.005). Transient airway narrowing was measured in three patients (2 ؋ PN;1 ؋ CR60) versus subjective chest tightness in seven patients (CR60 ® Ͼ PN). A shorter nebulization time for CR60 ® of 13.2 min compared to PN 16.1 min (p ‫؍‬ 0.022) was observed, which was the main reason why patients preferred the CR60 ® (n ‫؍‬ 7). No toxic serum levels were reached after inhalation of TSI. The CR60 ® compressor may seem advantageous based on a higher lung deposition and a shorter nebulization time, but a study in a large CF population to provide information on a possible higher risk of toxicity of TSI is called for.

The term aerosol, or particulate matter (PM), defines a colloidal mixture where liquid and solid particles are suspended in the air. Aerosols are an integral part of the atmosphere and they therefore interact with solar radiation by affecting climate (primary and secondary effect) and atmospheric visibility. Aerosols also impact human health as they are associated with cardiopulmonary and airways diseases.
This dissertation project focuses on critical aspects of optical particle counters (OPCs), which are based on light scattering to return the particle number concentration and size distribution of airborne aerosol on a real-time basis. The goals of this work are:

1) to characterise and improve the performances of a novel OPC (CompactOPC N1, Alphasense; hereafter COPC) against a standard commercial OPC (Grimm 1.108; hereafter GRM);

2) to build up a test bench for calibrating an OPC used in clean room and sanitary environments (Laser Particle Sensor 3715-00, Kanomax; hereafter LPS). Pollution S.r.l., the Italian producer and distributor of the LPS is keen on this goal, since calibrations of this OPC are not performed in Italy.

Experimental tests were carried out with indoor aerosol and monodisperse spheres of polystyrene latex (PSL) of different sizes, by sampling with all OPCs and, in parallel, onto a filter to count particles at a scanning electron microscope (SEM), in order to obtain an absolute reference value for particle number concentration.
Results indicated a good agreement between the concentrations returned by the GRM and the ones obtained at the SEM. Also, in this work the COPC's performances could be improved by modifying its standard version. Furthermore, the calibration of the LPS could be carried out by using the test bench developed in this work.
The experimental work relating to this dissertation project was carried out in the
Laboratory for Aerosol and Cloud Physics of the Institute for Atmospheric and Climate Science (ISAC) at the Italian National Research Council (CNR) in Bologna.

by Abdelmaged Hafez Ibrahim Essawey This work presents a combined experimental and theoretical investigation of the conditions under which a fluid flow causes a microparticle to detach from a flat surface. The general approach was to conduct well-controlled experiments, to observe individual microparticle motion and to focus on the basic detachment mechanisms. Microparticles of different sizes, materials and shapes (mostly microspheres) were deposited as monolayers onto the substrates under controlled conditions. The microparticles attached to the substrate in a condition of static equilibrium due to contact adhesion and resided completely within the viscous sublayer. The flow was accelerated during a transient period up to a fixed, constant velocity. Smooth glass plates were used as substrates and scanned with an atomic force microscope to determine their roughness-height distributions. The study was confined to microparticles in the diameter range of approximately 10 µm to 100 µm. They were distributed on the surface as a monolayer in sparse/dense conditions, dry/humid and subjected to laminar or fully developed turbulent flows.

El objetivo de esta investigación fue identificar los
orígenes de las masas de aire en cuatro ciudades
colombianas (Bogotá, Cartagena de Indias,
Pasto y Leticia) que tienen el potencial de afectar
la calidad del aire urbano al transportar material
particulado a largas distancias desde diferentes
puntos geográficos. Metodológicamente se utilizó
información proporcionada por el modelo HYSPLIT
versión 4, con el cual se midieron retro-trayectorias
para un periodo de análisis de un año
(desde el 01 de enero a 31 de diciembre de 2012).
El cálculo de retrotrayectorias es de gran utilidad
para determinar la zona de partida de las masas
de aire que llegan en un momento determinado,
a un lugar concreto y a una altura definida. De
esta forma se obtuvieron retro-trayectorias diarias
registradas a las 12:00 UTC (tiempo universal
coordinado), con cálculos a intervalos de seis
horas, representando el transporte realizado por
la masa de aire los cinco días anteriores (120 h).
Las alturas isentrópicas consideradas fueron de
750, 1500 y 2500 m medidas desde el nivel del
suelo. Según los resultados obtenidos, el origen
de masas de aire más frecuente en Cartagena
de Indias durante 2012 fue Caribe (45%), seguido
por Continental (36%). En Bogotá fue Continental
(77%), seguido por Atlántico Este (19%). En Pasto
fue Pacífico (72%), seguido por Continental (23%).
Y en Leticia fue Continental (99%) seguido por el
origen Atlántico Este (1%).