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aerosol particle

Tadeusz Halatek, Magdalena Stanislawska, Irena Kaminska, Malgorzata Cieslak, Radoslaw Swiercz, Wojciech Wasowicz
Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. The principal objective of this study was to determine the dynamics of toxic effects of inhalation exposure to morphologically rated welding dust from stainless steel welding and its soluble form in TSE System with a dynamic airflow. We assessed the pulmonary toxicity of welding dust in Wistar rats exposed to 60...
November 30, 2016: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Pulong Chen, Tijian Wang, Xiaobo Lu, Yiyong Yu, Matthew Kasoar, Min Xie, Bingliang Zhuang
In this study, samples of size-fractionated particulate matter were collected continuously using a 9-size interval cascade impactor at an urban site in Nanjing, before, during and after the Asian Youth Games (AYG), from July to September of 2013, and the Youth Olympic Games (YOG), from July to September of 2014. First, elemental concentrations, water-soluble ions including Cl(-), NO3(-), SO4(2-), NH4(+), K(+), Na(+) and Ca(2+), organic carbon (OC) and elemental carbon (EC) were analysed. Then, the source apportionment of the fine and coarse particulate matter was carried out using the chemical mass balance (CMB) model...
November 21, 2016: Science of the Total Environment
F-X Ouf, P Parent, C Laffon, I Marhaba, D Ferry, B Marcillaud, E Antonsson, S Benkoula, X-J Liu, C Nicolas, E Robert, M Patanen, F-A Barreda, O Sublemontier, A Coppalle, J Yon, F Miserque, T Mostefaoui, T Z Regier, J-B A Mitchell, C Miron
Many studies have been conducted on the environmental impacts of combustion generated aerosols. Due to their complex composition and morphology, their chemical reactivity is not well understood and new developments of analysis methods are needed. We report the first demonstration of in-flight X-ray based characterizations of freshly emitted soot particles, which is of paramount importance for understanding the role of one of the main anthropogenic particulate contributors to global climate change. Soot particles, produced by a burner for several air-to-fuel ratios, were injected through an aerodynamic lens, focusing them to a region where they interacted with synchrotron radiation...
November 24, 2016: Scientific Reports
Esther Borrás, Milagros Ródenas, Teresa Vera, Tatiana Gómez, Amalia Muñoz
The gas phase atmospheric degradation of pirimiphos-methyl (a widely used organophosphate insecticide and acaricide in many European regions) has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. Its photolysis has been studied under sunlight conditions and its reaction rate constant with OH radicals was measured by the relative rate method. The reaction with ozone was also investigated. The tropospheric degradation of pirimiphos-methyl is controlled mainly by the OH radical reaction...
November 21, 2016: Science of the Total Environment
Zheming Tong, Bo Yang, Philip K Hopke, K Max Zhang
Initiatives to displace petroleum and climate change mitigation have driven a recent increase in space heating with biomass combustion. However, there is ample evidence that biomass combustion emits significant quantities of health damaging pollutants. We investigated the near-source micro-environmental air quality impact of a biomass-fueled combined heat and power system equipped with an electrostatic precipitator (ESP) in Syracuse, NY. Two rooftop sampling stations with PM2.5 and CO2 analyzers were established in such that one could capture the plume while the other one served as the background for comparison depending on the wind direction...
November 18, 2016: Environmental Pollution
Michael Dawson, Valeria Soro, David Dymock, Robert Price, Helen Griffiths, Tom Dudding, Jonathan R Sandy, Anthony J Ireland
INTRODUCTION: The aims of this study were to describe bacterial load and diversity of the aerosol created during enamel cleanup after the removal of fixed orthodontic appliances and to assess the effect of a preprocedural mouth rinse. METHODS: The study involved the sampling of ambient air adjacent to the patient's mouth during adhesive removal using a slow-speed handpiece and a spiral fluted tungsten carbide bur without water irrigation. Sampling was carried out during enamel cleanup with or without a preprocedural mouth rinse of either sterile water or chlorhexidine...
November 2016: American Journal of Orthodontics and Dentofacial Orthopedics
Rami Fishler, Yan Ostrovski, Chao-Yi Lu, Josué Sznitman
The dispersion of inhaled microparticles in the pulmonary acinus of the lungs is often attributed to the complex interplay between convective mixing, due to irreversible flows, and intrinsic particle motion (i.e. gravity and diffusion). However, the role of each mechanism, the exact nature of such interplay between them and their relative importance still remain unclear. To gain insight into these dispersive mechanisms, we track liquid-suspended microparticles and extract their effective diffusivities inside an anatomically-inspired microfluidic acinar model...
November 13, 2016: Journal of Biomechanics
Wen Zhang, Zhaochu Hu, Detlef Günther, Yongsheng Liu, Wenli Ling, Keqing Zong, Haihong Chen, Shan Gao
In situ Pb isotope data of sulfide samples measured by LA-MC-ICP-MS provide valuable geochemical information for studies of the origin and evolution of ore deposits. However, the severe isobaric interference of (204)Hg on (204)Pb and the lack of matrix-matched sulfide reference materials limit the precision of Pb isotopic analyses for Hg-rich sulfides. In this study, we observe that Hg forms vapor and can be completely removed from sample aerosol particles produced by laser ablation using a gas exchange device...
December 15, 2016: Analytica Chimica Acta
Zhiyun Ji, Xiaohui Fan, Min Gan, Xuling Chen, Wei Lv, Qiang Li, Yang Zhou, Ye Tian, Tao Jiang
The formation of PM2.5 (aerosol particulate matters less than 2.5 µm in aerodynamic diameter) in association with SO2 emission during sintering process has been studied by dividing the whole sintering process into 6 typical sampling stages. A low-pressure cascade impactor was used to collect PM2.5 by automatically segregating particulates into 6 sizes. It was found that strong correlation was existed between the emission properties of PM2.5 and SO2. Wet mixture layer (over-wetted layer and raw mixture layer) had the function to simultaneously capture SO2 and PM2...
November 21, 2016: Journal of the Air & Waste Management Association
Pengfei Yu, Owen B Toon, Charles G Bardeen, Anthony Bucholtz, Karen H Rosenlof, Pablo E Saide, Arlindo Da Silva, Luke D Ziemba, Kenneth L Thornhill, Jose-Luis Jimenez, Pedro Campuzano-Jost, Joshua P Schwarz, Anne E Perring, Karl D Froyd, N L Wagner, Michael J Mills, Jeffrey S Reid
The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by a climate model coupled with a size-resolved aerosol model. Modeled aerosol mass, number, and particle size distribution are within variability of data obtained from multiple-airborne in situ measurements. Simulations suggest that Rim Fire smoke may block 4-6% of sunlight energy reaching the surface, with a dimming efficiency around 120-150 W m(-2) per unit aerosol optical depth in the midvisible at 13:00-15:00 local time...
June 27, 2016: Journal of Geophysical Research. Atmospheres: JGR
Min Deng, Gerald G Mace, Zhien Wang, Elizabeth Berry
The CloudSat 2C-ICE data product is derived from a synergetic ice cloud retrieval algorithm that takes as input a combination of CloudSat radar reflectivity (Ze ) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation lidar attenuated backscatter profiles. The algorithm uses a variational method for retrieving profiles of visible extinction coefficient, ice water content, and ice particle effective radius in ice or mixed-phase clouds. Because of the nature of the measurements and to maintain consistency in the algorithm numerics, we choose to parameterize (with appropriately large specification of uncertainty) Ze and lidar attenuated backscatter in the regions of a cirrus layer where only the lidar provides data and where only the radar provides data, respectively...
December 16, 2015: Journal of Geophysical Research. Atmospheres: JGR
Hoda Rabea, Ahmed M A Ali, Randa Salah Eldin, Maha M Abdelrahman, Amira S A Said, Mohamed E Abdelrahim
Substituting nebulisers by another in non-invasive ventilation circuit (NIV) involves many process variables which must be adjusted to ensure patient optimum therapy. However, there is a doubt when nebulisers use the same technology. Data mining technology based on artificial neural networks and genetic algorithms were used here to model in-vitro inhalation process and predict bioavailability from inhaled doses delivered by three different vibrating mesh nebulisers (VMNs) in NIV. Modelling of data indicated that in-vitro performance of VMNs was dependent mainly on fine particle fraction, mass median aerodynamic diameter (MMAD), total emitted dose (TED) and to lesser extent on nebuliser type...
November 17, 2016: European Journal of Pharmaceutical Sciences
Leigh R Crilley, Franco Lucarelli, William J Bloss, Roy M Harrison, David C Beddows, Giulia Calzolai, Silvia Nava, Gianluigi Valli, Vera Bernardoni, Roberta Vecchi
London, like many major cities, has a noted air pollution problem, and a better understanding of the sources of airborne particles in the different size fractions will facilitate the implementation and effectiveness of control strategies to reduce air pollution. Thus, the trace elemental composition of the fine and coarse fraction were analysed at hourly time resolution at urban background (North Kensington, NK) and roadside (Marylebone Road, MR) sites within central London. Unlike previous work, the current study focuses on measurements during the summer providing a snapshot of contributing sources, utilising the high time resolution to improve source identification...
November 17, 2016: Environmental Pollution
Maria Malamatari, Satyanarayana Somavarapu, Kyriakos Kachrimanis, Mark Bloxham, Kevin M G Taylor, Graham Buckton
Inhalable theophylline particles with various amounts of mannitol were prepared by combining wet milling in isopropanol followed by spray drying. The effect of mannitol as a co-milling agent on the micromeritic properties, solid state and aerosol performance of the engineered particles was investigated. Crystal morphology modelling and geometric lattice matching calculations were employed to gain insight into the intermolecular interactions that may influence the mechanical properties of theophylline and mannitol...
November 30, 2016: International Journal of Pharmaceutics
Jessica M Oakes, Shawn C Shadden, Céline Grandmont, Irene E Vignon-Clementel
Little is known about transport throughout the respiration cycle in the conducting airways. It is challenging to appropriately describe the time-dependent number of particles entering back into the model during exhalation. Modeling the entire lung is not feasible; therefore multi-domain methods must be employed. Here, we present a new framework that is designed to simulate particles throughout the respiration cycle, incorporating realistic airway geometry and respiration. This framework is applied for a healthy rat lung exposed to  ∼ 1μm diameter particles to facilitate parameterization and validation...
November 2, 2016: International Journal for Numerical Methods in Biomedical Engineering
Patrick Vrancken, Martin Wirth, Gerhard Ehret, Hervé Barny, Philippe Rondeau, Henk Veerman
A high-performance airborne UV Rayleigh lidar system was developed within the European project DELICAT. With its forward-pointing architecture, it aims at demonstrating a novel detection scheme for clear air turbulence (CAT) for an aeronautics safety application. Due to its occurrence in clear and clean air at high altitudes (aviation cruise flight level), this type of turbulence evades microwave radar techniques and in most cases coherent Doppler lidar techniques. The present lidar detection technique relies on air density fluctuation measurement and is thus independent of backscatter from hydrometeors and aerosol particles...
November 10, 2016: Applied Optics
Michael Welte, Rafik Barhoumi, Adrian Zbinden, Jonathan R Scheffe, Aldo Steinfeld
We report on the experimental demonstration of an aerosol solar reactor for the thermal reduction of ceria, as part of a thermochemical redox cycle for splitting H2O and CO2. The concept utilizes a cavity-receiver enclosing an array of alumina tubes, each containing a downward gravity-driven aerosol flow of ceria particles countercurrent to an inert sweep gas flow for intrinsic separation of reduced ceria and oxygen. A 2 kWth lab-scale prototype with a single tube was tested under radiative fluxes approaching 4000 suns, yielding reaction extents of up to 53% of the thermodynamic equilibrium at 1919 K within residence times below 1 s...
October 12, 2016: Industrial & Engineering Chemistry Research
Christer Janson, Thomas Lööf, Gunilla Telg, Georgios Stratelis, Folke Nilsson
Multi-dose dry powder inhalers (DPIs) are commonly used in asthma and chronic obstructive lung disease (COPD) treatment. A disadvantage is their sensitivity to humidity. In real life, DPIs are periodically exposed to humid conditions, which may affect aerosol characteristics and lung deposition. This study compared DPI aerosol performance after exposure to humidity. Budesonide (BUD) inhalers (Turbuhaler; Novolizer; Easyhaler) and budesonide/formoterol (BUD/FORM) inhalers (Turbuhaler; Spiromax; Easyhaler) were stored in 75% relative humidity (RH) at both ambient temperature and at -0 °C...
November 17, 2016: NPJ Primary Care Respiratory Medicine
Gehui Wang, Renyi Zhang, Mario E Gomez, Lingxiao Yang, Misti Levy Zamora, Min Hu, Yun Lin, Jianfei Peng, Song Guo, Jingjing Meng, Jianjun Li, Chunlei Cheng, Tafeng Hu, Yanqin Ren, Yuesi Wang, Jian Gao, Junji Cao, Zhisheng An, Weijian Zhou, Guohui Li, Jiayuan Wang, Pengfei Tian, Wilmarie Marrero-Ortiz, Jeremiah Secrest, Zhuofei Du, Jing Zheng, Dongjie Shang, Limin Zeng, Min Shao, Weigang Wang, Yao Huang, Yuan Wang, Yujiao Zhu, Yixin Li, Jiaxi Hu, Bowen Pan, Li Cai, Yuting Cheng, Yuemeng Ji, Fang Zhang, Daniel Rosenfeld, Peter S Liss, Robert A Duce, Charles E Kolb, Mario J Molina
Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions...
November 14, 2016: Proceedings of the National Academy of Sciences of the United States of America
Michael Y Yang, Hak-Kim Chan
BACKGROUND: The measurement of aerosol flow rates without obscuration of the flow is of particular concern with in vivo lung deposition studies, where precise knowledge of aerosol particle size distributions is a necessary requirement for the development of predictive correlations. This study examines the utility of an ultrasonic flow meter for such measurements and determines if a valved system can be attached to the flow meter for sampling exhaled aerosols. METHODS: The flow rate across a D-30 flow meter was compared with and without nebulization of 0...
November 16, 2016: Journal of Aerosol Medicine and Pulmonary Drug Delivery
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