Simulation on a novel micron-array inertial impactor for submicron and ultrafine particle separation

2016 ◽  
Vol 30 (22) ◽  
pp. 1650273
Author(s):  
Rui-Tao Liu ◽  
Lu-Qi Tao ◽  
Yi Yang ◽  
Tian-Ling Ren
Keyword(s):  
Ultrafine Particles ◽  
Collection Efficiency ◽  
Ultrafine Particle ◽  
Particle Separation ◽  
Direct Writing ◽  
Research Directions ◽  
Separation Device ◽  
Novel Structure ◽  
Mems Technology ◽  
First Time

The particulate matter (PM), which was put forward in 1997 by US, had taken more and more attention due to the influence on human health. Although the mass concentration, number concentration and chemical composition of PM were still major research directions, how to collect these PMs more efficiently becomes critical. Inertial impactor is an effective separation device, however, due to different motion states of PM[Formula: see text] and PM[Formula: see text] in the flow field, the inertial impactor which can separate PM[Formula: see text] from other PMs has not been fabricated. In this work, the motion states for both submicron and ultrafine particles were studied by using classical theory of channel aerodynamic, and a novel micron-array inertial impactor was designed and simulated for the first time. Besides, the influence of some characteristic parameters (W, T, S, Dc, etc.) on particle collection efficiency were researched and discussed through simulation results. This novel structure can be easily fabricated by MEMS technology or laser direct writing and also can be widely used in particle separation or flexible sensor fields.

scholarly journals Impact on Ultrafine Particles Concentration and Turbulent Fluxes of SARS-CoV-2 Lockdown in a Suburban Area in Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 407
Author(s):  
Antonio Donateo ◽  
Adelaide Dinoi ◽  
Gianluca Pappaccogli
Keyword(s):  
Ultrafine Particles ◽  
Particle Number ◽  
Ultrafine Particle ◽  
Turbulent Fluxes ◽  
Number Concentration ◽  
Suburban Area ◽  
Observation Site ◽  
Meteorological Forcing ◽  
Restrictive Measures ◽  
Measurement Area

In order to slow the spread of SARS-CoV-2, governments have implemented several restrictive measures (lockdown, stay-in-place, and quarantine policies). These provisions have drastically changed the routines of residents, altering environmental conditions in the affected areas. In this context, our work analyzes the effects of the reduced emissions during the COVID-19 period on the ultrafine particles number concentration and their turbulent fluxes in a suburban area. COVID-19 restrictions did not significantly reduce anthropogenic related PM10 and PM2.5 levels, with an equal decrement of about 14%. The ultrafine particle number concentration during the lockdown period decreased by 64% in our measurement area, essentially due to the lower traffic activity. The effect of the restriction measures and the reduction of vehicles traffic was predominant in reducing concentration rather than meteorological forcing. During the lockdown in 2020, a decrease of 61% in ultrafine particle positive fluxes can be observed. At the same time, negative fluxes decreased by 59% and our observation site behaved, essentially, as a sink of ultrafine particles. Due to this behavior, we can conclude that the principal particle sources during the lockdown were far away from the measurement site.

scholarly journals Modeling metallurgical responses of coal Tri-Flo separators by a novel BNN: a “Conscious-Lab” development

2021 ◽  
Author(s):  
Mehdi Alidokht ◽  
Samaneh Yazdani ◽  
Esmaeil Hadavandi ◽  
Saeed Chehreh Chelgani
Keyword(s):  
Laboratory Experiments ◽  
Scaling Up ◽  
Dense Medium ◽  
Support Vector ◽  
Coal Processing ◽  
Separation Device ◽  
Modeling Methods ◽  
Machine Learning Methods ◽  
Coal Washery ◽  
First Time

AbstractTri-flo cyclone, as a dense-medium separation device, is one of the most typical environmentally friendly industrial techniques in the coal washery plants. Surprisingly, no detailed investigation has been conducted to explore the effectiveness of tri-flo cyclone operating parameters on their representative metallurgical responses (yield and recovery). To fill this gap, this work for the first time in the coal processing sector is going to introduce a type of advanced intelligent method (boosted-neural network “BNN”) which is able to linearly and nonlinearly assess multivariable correlations among all variables, rank them based on their effectiveness and model their produced responses. These assessments and modeling were considered a new concept called “Conscious Laboratory (CL)”. CL can markedly decrease the number of laboratory experiments, reduce cost, save time, remove scaling up risks, expand maintaining processes, and significantly improve our knowledge about the modeled system. In this study, a robust monitoring database from the Tabas coal plant was prepared to cover various conditions for building a CL for coal tri-flo separators. Well-known machine learning methods, random forest, and support vector regression were developed to validate BNN outcomes. The comparisons indicated the accuracy and strength of BNN over the examined traditional modeling methods. In a sentence, generating a novel BNN within the CL concept can apply in various energy and coal processing areas, fill gaps in our knowledge about possible interactions, and open a new window for plants' fully automotive process.

scholarly journals Ultrafine Particle and Fiber Production in Micro-Gravity

1986 ◽  
Vol 87 ◽  
Author(s):  
George W. Webb
Keyword(s):  
Experimental Test ◽  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Inert Gas ◽  
Reduced Gravity ◽  
Fiber Production ◽  
Evaporation And Condensation ◽  
Gravity Driven ◽  
Micro Gravity

AbstractWe have investigated the technique of evaporation and condensation of material in an inert gas (ECIIG) for the purpose of preparing ultrafine particles (of order 10 nm in diameter) with a narrow distribution of sizes. Gravity driven convection increases the rate of coalescence of the particles leading to larger sizes and a broader distribution. Here we report on analysis and experiments to investigate coalescence of particles. The possibility of reducing coalescence in micro-gravity is discussed. An experimental test in reduced gravity to be performed in a KC135 aircraft is described briefly.

scholarly journals Simultaneous coastal measurements of ozone deposition fluxes and iodine-mediated particle emission fluxes with subsequent CCN formation

2009 ◽  
Vol 9 (5) ◽  
pp. 20567-20597 ◽  
Author(s):  
J. D. Whitehead ◽  
G. McFiggans ◽  
M. W. Gallagher ◽  
M. J. Flynn
Keyword(s):  
Ultrafine Particles ◽  
Littoral Zone ◽  
Ultrafine Particle ◽  
High Tide ◽  
Particle Growth ◽  
Particle Emission ◽  
Deposition Fluxes ◽  
Ozone Deposition ◽  
Significant Difference ◽  
Emission Fluxes

Abstract. Here we present the first observations of simultaneous ozone deposition fluxes and ultrafine particle emission fluxes over an extensive infra-littoral zone. Fluxes were measured by the eddy covariance technique at the Station Biologique de Roscoff, on the coast of Brittany, north-west France. This site overlooks a very wide (3 km) littoral zone controlled by very deep tides (9.6 m) exposing extensive macroalgae beds available for significant iodine mediated photochemical production of ultrafine particles. The aspect at the Station Biologique de Roscoff provides an extensive and relatively flat, uniform fetch within which micrometeorological techniques may be utilized to study links between ozone deposition to macroalgae (and sea water) and ultrafine particle production. Ozone deposition to seawater at high tide was significantly slower (vd[O3]=0.302±0.095 mm s−1) than low tidal deposition. A statistically significant difference in the deposition velocities to macroalgae at low tide was observed between night time (vd[O3]=1.00±0.10 mm s−1) and daytime (vd[O3]=2.05±0.16s−1) when ultrafine particle formation results in apparent particle emission. Very high emission fluxes of ultrafine particles were observed during daytime periods at low tides ranging from 50 000 particles cm−2 s−1 to greater than 200 000 particles cm−2 s−1 during some of the lowest tides. These emission fluxes exhibited a significant relationship with particle number concentrations comparable with previous observations at another location. Apparent particle growth rates were estimated to be in the range 17–150 nm h−1 for particles in the size range 3–10 nm. Under certain conditions, particle growth may be inferred to continue to greater than 120 nm over tens of hours; sizes at which they may readily behave as cloud condensation nuclei (CCN) under reasonable supersaturations that may be expected to pertain at the top of the marine boundary layer. These results link direct depositional loss and photochemical destruction of ozone to the formation of particles and hence CCN from macroalgal emissions at a coastal location.

scholarly journals Laboratory and field evaluation of the Aerosol Dynamics Inc. concentrator (ADIc) for aerosol mass spectrometry

2019 ◽  
Author(s):  
Sanna Saarikoski ◽  
Leah R. Williams ◽  
Steven R. Spielman ◽  
Gregory S. Lewis ◽  
Arantzazu Eiguren-Fernandez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Concentration Factor ◽  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Chemical Characterization ◽  
Field Evaluation ◽  
Aerosol Dynamics ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Road Paving

Abstract. An air-to-air ultrafine particle concentrator (Aerosol Dynamics Inc. concentrator; ADIc) has been designed to enhance on-line chemical characterization of ambient aerosols by aerosol mass spectrometry. The ADIc employs a three-stage, moderated water-based condensation growth tube coupled to an aerodynamic focusing nozzle to concentrate ultrafine particles into a portion of the flow. The system can be configured to sample between 1.0–1.7 L min−1 with an output concentrated flow between 0.08–0.12 L min−1, resulting in a theoretical concentration factor (sample flow/output flow) ranging from 8 to 21. Laboratory tests with monodisperse particles show that the ADIc is effective for particles as small as 10 nm. Laboratory experiments conducted with the Aerosol Mass Spectrometer (AMS) showed no shift in the particle size after the ADIc, as measured by the AMS particle time-of-flight. The ADIc-AMS system was operated unattended over a one-month period near Boston, Massachusetts. Comparison to a parallel AMS without the concentrator showed concentration factors of 9.7 ± 0.15 and 9.1 ± 0.1 for sulfate and nitrate, respectively, when operated with a theoretical concentration factor of 10.5 ± 0.3. Concentration factor of organics was lower, possibly due to the presence of large particles from nearby road-paving operations, and a difference in aerodynamic lens cutoff between the two AMS instruments. Another field deployment was carried out in Helsinki, Finland. Two ~ 10-day measurement periods showed good correlation for the concentrations of organics, sulfate, nitrate and ammonium measured with an Aerosol Chemical Speciation Monitor (ACSM) after the ADIc, and a parallel AMS without the concentrator. Additional experiments with an AMS alternating between the ADIc and a bypass line demonstrated that the concentrator did not change the size distribution or the chemistry of the ambient aerosol particles.

scholarly journals An embryonic zebrafish model to screen disruption of gut-vascular-barriers upon exposure to ambient ultrafine particles

2020 ◽  
Author(s):  
Kyung In Baek ◽  
Yi Qian ◽  
Chih-Chiang Chang ◽  
Ryan O’Donnell ◽  
Ehsan Soleimanian ◽  
...  
Keyword(s):  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Intestinal Barrier ◽  
Epidemiological Studies ◽  
Ambient Particulate Matter ◽  
Zebrafish Model ◽  
Redox Active ◽  
Capillary Plexus ◽  
Polycyclic Aromatic ◽  
Notch Activation

AbstractEpidemiological studies have linked exposure to ambient particulate matter (PM) with gastrointestinal (GI) diseases. Ambient ultrafine particle (UFP) are the redox-active sub-fraction of PM2.5, harboring elemental and polycyclic aromatic hydrocarbons from urban environmental sources including diesel and gasoline exhausts. The gut vascular barrier (GVB) regulates paracellular trafficking and systemic disseminations of ingested microbes and toxins. Here, we posit that acute UFP ingestion disrupts the integrity of the intestinal barrier by modulating intestinal Notch activation. Using zebrafish embryos, we performed micro-gavage with the FITC-conjugated dextran (FD10, 10 kDa) to assess the disruption of GVB integrity upon UFP exposure. Following micro-gavage, FD10 retained in the embryonic GI system, migrated through the cloaca. Conversely, co-gavaging UFP increased transmigration of FD10 across the intestinal barrier, and FD10 fluorescence occurred in the venous capillary plexus. Ingestion of UFP further impaired the mid-intestine morphology. We performed micro-angiogram of FD10 to corroborate acute UFP-mediated disruption of GVB. Transient genetic and pharmacologic manipulations of global Notch activity suggested Notch regulation of the GVB. Overall, our integration of a genetically tractable embryonic zebrafish and micro-gavage technique provided epigenetic insights underlying ambient UFP ingestion disrupts the GVB.Graphic Abstract

scholarly journals Summertime observations of elevated levels of ultrafine particles in the high Arctic marine boundary layer

2017 ◽  
Vol 17 (8) ◽  
pp. 5515-5535 ◽  
Author(s):  
Julia Burkart ◽  
Megan D. Willis ◽  
Heiko Bozem ◽  
Jennie L. Thomas ◽  
Kathy Law ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Ultrafine Particles ◽  
Marine Boundary Layer ◽  
Ultrafine Particle ◽  
High Arctic ◽  
Particle Formation ◽  
Open Ocean ◽  
Biologically Active ◽  
The Arctic ◽  
Depositional Processes

Abstract. Motivated by increasing levels of open ocean in the Arctic summer and the lack of prior altitude-resolved studies, extensive aerosol measurements were made during 11 flights of the NETCARE July 2014 airborne campaign from Resolute Bay, Nunavut. Flights included vertical profiles (60 to 3000 m above ground level) over open ocean, fast ice, and boundary layer clouds and fogs. A general conclusion, from observations of particle numbers between 5 and 20 nm in diameter (N5 − 20), is that ultrafine particle formation occurs readily in the Canadian high Arctic marine boundary layer, especially just above ocean and clouds, reaching values of a few thousand particles cm−3. By contrast, ultrafine particle concentrations are much lower in the free troposphere. Elevated levels of larger particles (for example, from 20 to 40 nm in size, N20 − 40) are sometimes associated with high N5 − 20, especially over low clouds, suggestive of aerosol growth. The number densities of particles greater than 40 nm in diameter (N >  40) are relatively depleted at the lowest altitudes, indicative of depositional processes that will lower the condensation sink and promote new particle formation. The number of cloud condensation nuclei (CCN; measured at 0.6 % supersaturation) are positively correlated with the numbers of small particles (down to roughly 30 nm), indicating that some fraction of these newly formed particles are capable of being involved in cloud activation. Given that the summertime marine Arctic is a biologically active region, it is important to better establish the links between emissions from the ocean and the formation and growth of ultrafine particles within this rapidly changing environment.

Experiment, Theory, and Simulation of a Flow-Electrical-Split Flow Thin Particle Separation Device

2021 ◽  
pp. 462634
Author(s):  
Kevin Petersen ◽  
Farhad Shiri ◽  
Tonguc Onur Tasci ◽  
Himanshu Sant ◽  
Joshua Hood ◽  
...  
Keyword(s):  
Particle Separation ◽  
Separation Device ◽  
Split Flow

scholarly journals Sources and Eco-toxicological Effects of Ultrafine Particle Matters

2019 ◽  
Vol 136 ◽  
pp. 06008
Author(s):  
SHAN Huimei ◽  
LUO Linbo ◽  
WANG Shaopei ◽  
LIAO Danxue ◽  
ZHAO Chaoran ◽  
...  
Keyword(s):  
Pollution Control ◽  
Air Pollutants ◽  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Ambient Air ◽  
Toxicological Effects ◽  
Atmospheric Particulates ◽  
Environmental Air ◽  
Main Components ◽  
Environmental Air Pollution

Environmental air pollution has become an important threat to human health. As one of the major air pollutants, atmospheric particulates have received attention widely. In which, ultrafine particulate matters (UPM) with diameter below 0.1μm have become the main components of ambient air particulates, posing a serious threat to the health of the organism. Therefore, this paper investigated and summarized the research on ultrafine particles at home and abroad, systematically analysed the sources of UPM in ambient air, investigated its toxicological effects of ultrafine particles on the respiratory system, cardiovascular system, and central nervous system of organisms. This study will provide a theoretical reference for environmental air protection and pollution control in China.

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