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https://www.readbyqxmd.com/read/28441740/a-miniature-aerosol-sensor-for-detecting-polydisperse-airborne-ultrafine-particles
#1
Chao Zhang, Dingqu Wang, Rong Zhu, Wenming Yang, Peng Jiang
Counting and sizing of polydisperse airborne nanoparticles have attracted most attentions owing to increasing widespread presence of airborne engineered nanoparticles or ultrafine particles. Here we report a miniature aerosol sensor to detect particle size distribution of polydisperse ultrafine particles based on ion diffusion charging and electrical detection. The aerosol sensor comprises a couple of planar electrodes printed on two circuit boards assembled in parallel, where charging, precipitation and measurement sections are integrated into one chip, which can detect aerosol particle size in of 30-500 nm, number concentration in range of 5 × 10²-10⁷ /cm³...
April 22, 2017: Sensors
https://www.readbyqxmd.com/read/28441489/a-comparison-of-gasoline-direct-injection-gdi-and-port-fuel-injection-pfi-vehicle-emissions-emission-certification-standards-cold-start-secondary-organic-aerosol-formation-potential-and-potential-climate-impacts
#2
Georges Saliba, Rawad Saleh, Yunliang Zhao, Albert A Presto, Andrew T Lambe, Bruce Frodin, Satya Sardar, Hector Maldonado, Christine Maddox, Andrew A May, Greg T Drozd, Allen H Goldstein, Lynn M Russell, Fabian P Hagen, Allen L Robinson
Recent increases in the Corporate Average Fuel Economy standards have led to widespread adoption of vehicles equipped with gasoline direct injection (GDI) engines. Changes in engine technologies can alter emissions. To quantify these effects, we measured gas- and particle-phase emissions from eighty-two light duty gasoline vehicles recruited from the California in-use fleet tested on a chassis dynamometer using the cold-start unified cycle. The fleet included 15 GDI vehicles, including 8 GDIs certified to the most stringent emissions standard, super-ultra-low-emission vehicles (SULEV)...
April 25, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28441181/inhaled-treprostinil-drug-delivery-during-mechanical-ventilation-and-spontaneous-breathing-using-two-different-nebulizers
#3
Donna K Parker, Shuijie Shen, Jiang Zheng, D Dunbar Ivy, Dave N Crotwell, Justin C Hotz, Robert M DiBlasi
OBJECTIVES: To determine the feasibility of delivering inhaled treprostinil during mechanical ventilation and spontaneous unassisted ventilation using the Tyvaso Inhalation System and the vibrating mesh nebulizer. We sought to compare differences in fine particle fraction, and absolute inhaled treprostinil mass delivered to neonatal, pediatric, and adult models affixed with a face mask, conventional, and high-frequency ventilation between Tyvaso Inhalation System and with different nebulizer locations between Tyvaso Inhalation System and vibrating mesh nebulizer...
April 22, 2017: Pediatric Critical Care Medicine
https://www.readbyqxmd.com/read/28440646/aqueous-reaction-of-dicarbonyls-with-ammonia-as-a-potential-source-of-organic-nitrogen-in-airborne-nanoparticles
#4
Christopher M Stangl, Murray V Johnston
Nitrogen-containing organic species such as imines and imidazoles can be formed by aqueous reactions of carbonyl-containing compounds in the presence of ammonia. In the work described here, these reactions are studied in airborne aqueous nanodroplets containing ammonium sulfate and glyoxal, methylglyoxal, or glycolaldehyde using a combination of online and offline mass spectrometry. N/C ratios attributed to the organic fraction of the particles (N/Corg) produced from glyoxal and methylglyoxal were quantified across a wide relative humidity range...
April 25, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28437960/wind-ranging-and-velocimetry-with-low-peak-power-and-long-duration-modulated-laser
#5
Eiichi Yoshikawa, Tomoo Ushio
A novel approach to simultaneous wind ranging and velocimetry using low peak power, long-duration modulated laser pulse transmissions is proposed. Received signals backscattered by aerosol particles are processed by a multi-reference matched-filter (MRMF) which performs matched filter processing between the received signal and several reference signals in parallel and outputs a range-velocity profile of received power. Ranging and velocimetry are performed simultaneously by estimating received power, radial velocity, and velocity dispersion from a velocity profile at an arbitrary range in the range-velocity profile...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437919/polarization-based-enhancement-of-ocean-color-signal-for-estimating-suspended-particulate-matter-radiative-transfer-simulations-and-laboratory-measurements
#6
Jia Liu, Xianqiang He, Jiahang Liu, Yan Bai, Difeng Wang, Tieqiao Chen, Yihao Wang, Feng Zhu
Absorption and scattering by molecules, aerosols and hydrosols, and the reflection and transmission over the sea surface can modify the original polarization state of sunlight. However, water-leaving radiance polarization, containing embedded water constituent information, has largely been neglected. Here, the efficiency of the parallel polarization radiance (PPR) for enhancing ocean color signal of suspended particulate matter is examined via vector radiative transfer simulations and laboratory experiments...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437650/indoor-to-outdoor-relationship-of-aerosol-particles-inside-a-naturally-ventilated-apartment-a-comparison-between-single-parameter-analysis-and-indoor-aerosol-model-simulation
#7
Tareq Hussein
The indoor-to-outdoor relationship of aerosol particles is affected by several mechanisms including penetration, ventilation rate, dry deposition rate and sources. Understanding the effect of these factors is essential for a deeper knowledge of the indoor-to-outdoor relationship. In real-life conditions, it is difficult to analyze these factors in a naturally ventilated environment. In this study, a naturally ventilated and an occupied apartment was used to investigate the indoor-to-outdoor relationship of aerosol particles by applying two different techniques; single-parameter analysis and indoor aerosol model simulation...
April 21, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28435179/real-time-measurement-of-size-resolved-elemental-composition-ratio-for-flame-synthesized-composite-nanoparticle-aggregates-using-a-tandem-smps-icp-oes
#8
Nathan Reed, Jiaxi Fang, Sanmathi Chavalmane, Pratim Biswas
Composite nanoparticles find application in catalysis, drug delivery, and energy storage and require increasingly fine control of their physical properties and composition. While composite nanoparticles have been widely synthesized and characterized, little work has systematically correlated the initial concentration of precursors and the final composition of flame synthesized composite nanoparticles. This relationship is explored in a diffusion flame aerosol reactor by coupling a scanning mobility particle sizer (SMPS) with an inductively coupled plasma optical emission spectrometer (ICP-OES)...
2017: Aerosol Science and Technology: the Journal of the American Association for Aerosol Research
https://www.readbyqxmd.com/read/28432908/particulate-matter-pollution-from-aviation-related-activity-at-a-small-airport-of-the-aegean-sea-insular-region
#9
C Psanis, E Triantafyllou, M Giamarelou, M Manousakas, K Eleftheriadis, G Biskos
The unprecedented growth in aviation during the last years has resulted in a notable increase of local air pollution related to airports. The impacts of aviation on air quality can be extremely high particularly around airports serving remote insular regions with pristine atmospheric environments. Here we report measurements that show how the atmospheric aerosol is affected by the activity at a small airport in a remote region. More specifically, we provide measurements performed at the airport of Mytilene, Greece, a regional yet international airport that serves the entire island of Lesvos; the third largest island of the country...
April 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28429776/global-distribution-of-particle-phase-state-in-atmospheric-secondary-organic-aerosols
#10
Manabu Shiraiwa, Ying Li, Alexandra P Tsimpidi, Vlassis A Karydis, Thomas Berkemeier, Spyros N Pandis, Jos Lelieveld, Thomas Koop, Ulrich Pöschl
Secondary organic aerosols (SOA) are a large source of uncertainty in our current understanding of climate change and air pollution. The phase state of SOA is important for quantifying their effects on climate and air quality, but its global distribution is poorly characterized. We developed a method to estimate glass transition temperatures based on the molar mass and molecular O:C ratio of SOA components, and we used the global chemistry climate model EMAC with the organic aerosol module ORACLE to predict the phase state of atmospheric SOA...
April 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28426290/development-of-a-thoracic-personal-sampler-system-for-co-sampling-of-sulfuric-acid-mist-and-sulfur-dioxide-gas
#11
Chih-Hsiang Chien, Alexandros Theodore, Chufan Zhou, Chang-Yu Wu, Yu-Mei Hsu, Brian Birky
A novel personal sampler was designed to measure inorganic acid mists and gases for determining human exposure levels to these acids in workplaces. This sampler consists of (1) a parallel impactor for classifying aerosol by size following the ISO/CEN/ACGIH defined human thoracic fraction, (2) a cellulose filter to collect the residual acid mist but allowing penetration of sulfur dioxide gas, and (3) an accordion-shaped porous membrane denuder (aPMD) for adsorbing the penetrating sulfur dioxide gas. Acid-resistant PTFE was chosen as the housing material to minimize sampling interference...
April 20, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28422480/chemical-characterization-of-gas-and-particle-phase-products-from-the-ozonolysis-of-%C3%AE-pinene-in-the-presence-of-dimethylamine
#12
Geoffroy Duporté, Matthieu Riva, Jevgeni Parshintsev, Enna Heikkinen, Luis M F Barreira, Nanna Myllys, Liine Heikkinen, Kari Mikael Hartonen, Markku Kulmala, Mikael Ehn, Marja-Liisa Riekkola
Amines are recognized as key compounds in new particle formation (NPF) and secondary organic aerosol (SOA) formation. In addition, ozonolysis of α-pinene contributes substantially to the formation of biogenic SOAs in the atmosphere. In the present study, ozonolysis of α-pinene in presence of dimethylamine (DMA) was investigated in a flow tube reactor. Effects of amines on SOA formation and chemical composition were examined. Enhancement of NPF and SOA formation was observed in presence of DMA. Chemical characterization of gas- and particle-phase products by high-resolution mass spectrometric techniques revealed the formation of nitrogen containing compounds...
April 19, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28421352/a-new-role-of-fine-excipient-materials-in-carrier-based-dry-powder-inhalation-mixtures-effect-on-deagglomeration-of-drug-particles-during-mixing-revealed
#13
Ahmed O Shalash, Mustafa M A Elsayed
The potential of fine excipient materials to improve the performance of carrier-based dry powder inhalation mixtures is well acknowledged. The mechanisms underlying this potential are, however, open to question till date. Elaborate understanding of these mechanisms is a requisite for rational rather than empirical development of ternary dry powder inhalation mixtures. While effects of fine excipient materials on drug adhesion to and detachment from surfaces of carrier particle have been extensively investigated, effects on other processes, such as carrier-drug mixing, capsule/blister/device filling, or aerosolization in inhaler devices, have received little attention...
April 18, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28418936/deposition-and-spatial-variation-of-thoron-decay-products-in-a-thoron-experimental-house-using-the-direct-thoron-progeny-sensors
#14
R Mishra, M Joshi, O Meisenberg, S Gierl, R Prajith, S D Kanse, R Rout, B K Sapra, Y S Mayya, J Tschiersch
Experiments have been carried out using the deposition-based Direct Thoron Progeny Sensors (DTPS) in a thoron experimental house. The objective was to study the thoron decay product characteristics such as the deposition velocities, spatial variability and dependence on aerosol particle concentrations. Since the deposition velocity is an important characteristic in the calibration of the DTPS, it is very important to study its dependence on aerosol concentration in a controlled environment. At low aerosol concentration (1500 particles/cm(3)) the mean effective deposition velocity was measured to be 0...
April 18, 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/28415861/atmospheric-aerosols-clouds-chemistry-and-climate
#15
V Faye McNeill
Although too small to be seen with the human eye, atmospheric particulate matter has major impacts on the world around us, from our health to global climate. Understanding the sources, properties, and transformations of these particles in the atmosphere is among the major challenges in air quality and climate research today. Significant progress has been made over the past two decades in understanding atmospheric aerosol chemistry and its connections to climate. Advances in technology for characterizing aerosol chemical composition and physical properties have enabled rapid discovery in this area...
April 17, 2017: Annual Review of Chemical and Biomolecular Engineering
https://www.readbyqxmd.com/read/28414337/development-of-an-incoherent-broad-band-cavity-enhanced-aerosol-extinction-spectrometer-and-its-application-to-measurement-of-aerosol-optical-hygroscopicity
#16
Weixiong Zhao, Xuezhe Xu, Bo Fang, Qilei Zhang, Xiaodong Qian, Shuo Wang, Pan Liu, Weijun Zhang, Zhenzhu Wang, Dong Liu, Yinbo Huang, Dean S Venables, Weidong Chen
We report on the development of a blue light-emitting-diode-based incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for the measurement of the aerosol extinction coefficient at λ=461  nm. With an effective absorption path length of 2.8 km, an optimum detection limit of 0.05  Mm<sup>-1</sup> (5×10<sup>-10</sup>  cm<sup>-1</sup>) was achieved with an averaging time of 84 s. The baseline drift of the developed spectrometer was about ±0...
April 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/28410542/estimation-of-critical-supersaturation-solubility-ratio-for-predicting-diameters-of-dry-particles-prepared-by-air-jet-atomization-of-solutions
#17
Mahak Sapra, Suraj Ugrani, Y S Mayya, Chandra Venkataraman
Air-jet atomization of solution into droplets followed by controlled drying is increasingly being used for producing nanoparticles for drug delivery applications. Nanoparticle size is an important parameter that influences the stability, bioavailability and efficacy of the drug. In air-jet atomization technique, dry particle diameters are generally predicted by using solute diffusion models involving the key concept of critical supersaturation solubility ratio (Sc) that dictates the point of crust formation within the droplet...
April 6, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28407596/super-enhanced-particle-nucleation-in-styrene-emulsion-polymerization-in-the-presence-of-sodium-styrene-sulfonate
#18
Lorena Farias-Cepeda, Jorge Herrera-Ordonez, Angel R Hernandez-Martinez, Miriam Estevez, Lucero Rosales-Marines
The styrene (St) emulsion polymerization using Aerosol MA80 as surfactant and in the presence of sodium styrene sulfonate (NaSS) was studied. The effect of NaSS content was assessed using MA80 concentrations below and at the critical micellar concentration. It was found that at the higher NaSS and MA80 contents, the number of particles (N) reaches a maximum of the order of 10(17)particles/cm(3) water, a huge value that has never been reported. In this work an explanation for this super-enhanced particle nucleation phenomenon is proposed...
April 7, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28406371/inhalation-exposure-during-spray-application-and-subsequent-sanding-of-a-wood-sealant-containing-zinc-oxide-nanoparticles
#19
Michael R Cooper, Gavin H West, Leonard G Burrelli, Daniel Dresser, Kelsey N Griffin, Alan M Segrave, Jon Perrenoud, Bruce E Lippy
Nano-enabled construction products have entered into commerce. There are concerns about the safety of manufactured nanomaterials, and exposure assessments are needed for a more complete understanding of risk. This study assessed potential inhalation exposure to ZnO nanoparticles during spray application and power sanding of a commercially available wood sealant and evaluated the effectiveness of local exhaust ventilation in reducing exposure. A tradesperson performed the spraying and sanding inside an environmentally-controlled chamber...
April 13, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28406366/detection-of-pathogenic-bioaerosols-and-occupational-risk-in-a-philippine-landfill-site
#20
Hera Angela M Pagalilauan, Cielo Emar M Paraoan, Pierangeli G Vital
Payatas landfill site is one of the major dumpsites in the Philippines. In this study, the landfill was evaluated regarding the presence and concentration of pathogenic bacterial aerosols through culture and molecular techniques. Bioaerosols are biological airborne particles that may or may not cause diseases. Active sampling was done using MAS-100 Air Sampler from both indoor and outdoor locations. To test the accuracy of the culture method, those that were presumptively identified as Staphylococcus aureus and Klebsiella pneumoniae were subjected to molecular analysis using 16s rRNA sequencing, and as a result, they were identified as different species...
April 13, 2017: Archives of Environmental & Occupational Health
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