Reducing particle loss in a critical orifice and an aerodynamic lens for focusing aerosol particles in a wide size range of 30 nm — 10 μm

2015 ◽  
Vol 29 (1) ◽  
pp. 317-323 ◽  
Author(s):  
Tae-Hyun Hwang ◽  
Seok-Hwan Kim ◽  
Soo Hyung Kim ◽  
Donggeun Lee
Keyword(s):  
Size Range ◽  
Aerosol Particles ◽  
Particle Loss ◽  
Wide Size Range

scholarly journals Laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF): performance, reference spectra and classification of atmospheric samples

2018 ◽  
Vol 11 (4) ◽  
pp. 2325-2343 ◽  
Author(s):  
Xiaoli Shen ◽  
Ramakrishna Ramisetty ◽  
Claudia Mohr ◽  
Wei Huang ◽  
Thomas Leisner ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Aerosol Particle ◽  
Mass Spectrometer ◽  
Size Range ◽  
Aerosol Particles ◽  
Time Of Flight ◽  
Polystyrene Latex ◽  
Dust Particles ◽  
Data Set ◽  
Flight Mass Spectrometer

Abstract. The laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem, and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from  ∼  (0.01 ± 0.01) to  ∼  (4.23 ± 2.36) % for polystyrene latex (PSL) in the size range of 200 to 2000 nm,  ∼  (0.44 ± 0.19) to  ∼  (6.57 ± 2.38) % for ammonium nitrate (NH4NO3), and  ∼  (0.14 ± 0.02) to  ∼  (1.46 ± 0.08) % for sodium chloride (NaCl) particles in the size range of 300 to 1000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO3, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core–organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary 1-day ambient data set was analysed by both classical fuzzy clustering and a reference-spectra-based classification method. Resulting identified particle types were generally well correlated. We show how a combination of both methods can greatly improve the interpretation of single-particle data in field measurements.

The Mechanism of active capture of animal food by the Sergestid Shrimp Acetes Sibogae Australis

1998 ◽  
Vol 78 (2) ◽  
pp. 497-508 ◽  
Author(s):  
Lachlan Mcleay ◽  
C.G. Alexander
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Prey Capture ◽  
Size Range ◽  
The Third ◽  
Feeding Modes ◽  
In Captivity ◽  
Combined Actions ◽  
Wide Size Range ◽  
Scanning Electron

Combining the use of scanning electron microscopy and microcinematography with functional and behavioural observations has clarified many aspects underlying the feeding processes of the small planktonic sergestid shrimp Acetes sibogae australis. In captivity Acetes sibogae australis is an opportunistic feeder that uses four principal feeding modes to capture a wide size range of prey: Artemia nauplii (<0.33 mm), copepods (<1mm) and moribund Acetes (up to 25 mm). Prey capture is effected by combined actions of the first three pairs of pereiopods and the third maxillipeds before transfer to the more dorsal second maxillipeds. The second maxillipeds are the principal appendages used in securing, manipulating, sorting and rejecting prey before insertion into the vicinity of the inner mouthparts.

scholarly journals Stable carbon and nitrogen isotope ratio in PM1 and size segregated aerosol particles over the Baltic Sea

2019 ◽  
Vol 59 (3) ◽  
Author(s):  
Inga Garbarienė ◽  
Vidmantas Remeikis ◽  
Agnë Mašalaitė ◽  
Andrius Garbaras ◽  
Tpmasz Petelski ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Size Range ◽  
Road Traffic ◽  
Aerosol Particles ◽  
Nitrogen Isotope ◽  
Total Carbon ◽  
Formation Mechanisms ◽  
The Baltic Sea ◽  
Air Masses ◽  
The Baltic

We analysed δ13C of total carbon (TC) and δ15N of total nitrogen (TN) in submicron (PM1) and size segregated aerosol particles (PM0.056–2.5) collected during a cruise in the Baltic Sea from 9 to 17 November 2012. PM1 were characterized by the highest δ13C (–26.4‰) and lowest δ15N (–0.2 and 0.8‰) values when air masses arrived from the southwest direction (Poland). The obtained δ13C values indicated that combined emissions of coal and diesel/gasoline combustion were the most likely sources of TC. The depleted δ15N values indicated that TN originated mainly from liquid fuel combustion (road traffic, shipping) during this period. The lowest δ13C and highest δ15N values were determined in PM1 samples during the western airflow when the air masses had no recent contact with land. The highest δ15N values were probably associated with chemical aging of nitrogenous species during long-range transport, the lowest δ13C values could be related to emissions from diesel/gasoline combustion, potentially from ship traffic. The δ13C analysis of size-segregated aerosol particles PM0.056–2.5 revealed that the lowest δ13C values were observed in the size range from 0.056 to 0.18 µm and gradual 13C enrichment occurred in the size range from 0.18 to 2.5 µm due to different sources or formation mechanisms of the aerosols.

scholarly journals The mathematical principles and design of the NAIS – a spectrometer for the measurement of cluster ion and nanometer aerosol size distributions

2013 ◽  
Vol 6 (4) ◽  
pp. 1061-1071 ◽  
Author(s):  
S. Mirme ◽  
A. Mirme
Keyword(s):  
Size Range ◽  
Aerosol Particles ◽  
Charged Particles ◽  
Cluster Ions ◽  
Size Distributions ◽  
Neutral Cluster ◽  
Design Data ◽  
Cluster Ion ◽  
Principles Of Design ◽  
Spectrum Deconvolution

Abstract. The paper describes the Neutral cluster and Air Ion Spectrometer (NAIS) – a multichannel aerosol instrument capable of measuring the distribution of ions (charged particles and cluster ions) of both polarities in the electric mobility range from 3.2 to 0.0013 cm2 V−1 s−1 and the distribution of aerosol particles in the size range from 2.0 to 40 nm. We introduce the principles of design, data processing and spectrum deconvolution of the instrument.

scholarly journals Experimental evidence of the rear capture of aerosol particles by raindrops

2017 ◽  
Vol 17 (6) ◽  
pp. 4159-4176 ◽  
Author(s):  
Pascal Lemaitre ◽  
Arnaud Querel ◽  
Marie Monier ◽  
Thibault Menard ◽  
Emmanuel Porcheron ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Size Range ◽  
Collection Efficiency ◽  
Aerosol Particles ◽  
Experimental Studies ◽  
Laboratory Measurements ◽  
Experimental Proof ◽  
Theoretical Approaches ◽  
Capture Mechanism ◽  
Mode Size

Abstract. This article presents new measurements of the efficiency with which aerosol particles of accumulation mode size are collected by a 1.25 mm sized raindrop. These laboratory measurements provide the link to reconcile the scavenging coefficients obtained from theoretical approaches with those from experimental studies. We provide here experimental proof of the rear capture mechanism in the flow around drops, which has a fundamental effect on submicroscopic particles. These experiments thus confirm the efficiencies theoretically simulated by Beard (1974). Finally, we propose a semi-analytical expression to take into account this essential mechanism to calculate the collection efficiency for drops within the rain size range.

The effect of oleic acid on the synthesis of Fe3−xO4 nanoparticles over a wide size range

2015 ◽  
Vol 17 (41) ◽  
pp. 27373-27379 ◽  
Author(s):  
Carlos Moya ◽  
Xavier Batlle ◽  
Amílcar Labarta
Keyword(s):  
Thermal Decomposition ◽  
Oleic Acid ◽  
Structural Properties ◽  
Acid Concentration ◽  
Size Range ◽  
Benzyl Ether ◽  
Oleic Acid Concentration ◽  
Wide Size Range

This work reports on the effect of the oleic acid concentration on the magnetic and structural properties of Fe3−xO4 nanoparticles synthesized by thermal decomposition of Fe(acac)3 in benzyl-ether.

Production, Characterization, and Deposition of Carbon Clusters

1990 ◽  
Vol 206 ◽  
Author(s):  
Y. K. Bae ◽  
D. C. Lorents ◽  
R. Malhotra ◽  
C. H. Becker ◽  
D. Tse ◽  
...  
Keyword(s):  
High Temperatures ◽  
Thermal Desorption ◽  
Size Range ◽  
Ion Source ◽  
Carbon Clusters ◽  
Heating Process ◽  
Cluster Ion Source ◽  
Semiconductor Clusters ◽  
Cluster Ion ◽  
Wide Size Range

ABSTRACTWe have developed a new cluster ion source that can generate intense beams of metal and semiconductor clusters of a very wide-size range. With the source, we have observed intense beams of carbon clusters with mean cluster sizes of up to 4000 atoms/clusters. However, we have found that for generating small fullerenes, such as C60 and C70, the recently discovered technique by Kraetschmer et al. is much more efficient. By improving the technique, we have generated gram quantities of C60 and C70 and systematically investigated their thermal desorption properties. During the heating process, we have discovered that at high temperatures the bulk fullerenes, fullerite, transformed to another form of carbon, which still evaporates at temperatures above 700 C, but does not dissolve in benzene.

Forming Load Calculation of Hot Precision Forging of Cylindrical Gears

2013 ◽  
Vol 456 ◽  
pp. 425-428
Author(s):  
Bin Zuo ◽  
Bao Yu Wang ◽  
Le Yi Yang
Keyword(s):  
Impact Factor ◽  
Size Range ◽  
Fe Simulation ◽  
Helical Gears ◽  
Forging Process ◽  
Cylindrical Gears ◽  
Forming Load ◽  
Precision Forging ◽  
Load Calculation ◽  
Wide Size Range

The Tooth Impact Factor was defined and introduced into the formula of forming load of closed-upsetting. Thus the formula for calculating the forming load of hot precision forging of cylindrical gears was put forward. The equation for the Tooth Impact Factor was fitted using the data from FE simulation of forging process in which gears with different modules were forged. Some forging tests for gears were conducted and the forming load was measured to ensure the validity of the formula. The tests also revealed that the formula is suitable for forming load calculation of hot precision forging of both spur and helical gears in a wide size range.

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