Performance assessment of a portable nephelometer for outdoor particle mass measurement

2018 ◽  
Vol 20 (2) ◽  
pp. 370-383 ◽  
Author(s):  
Zhanyong Wang ◽  
Dongsheng Wang ◽  
Zhong-Ren Peng ◽  
Ming Cai ◽  
Qingyan Fu ◽  
...  
Keyword(s):  
Performance Assessment ◽  
Mass Measurement ◽  
Particle Mass ◽  
Mass Measurements

The availability of a portable nephelometer for outdoor PM1.0(≤1.0 μm), PM2.5(≤2.5 μm) and PM10(≤10 μm) mass measurements is assessed in Shanghai, China.

scholarly journals Kinematic focus point method for particle mass measurements in missing energy events

2019 ◽  
Vol 2019 (10) ◽  
Author(s):  
Doojin Kim ◽  
Konstantin T. Matchev ◽  
Prasanth Shyamsundar
Keyword(s):  
Point Method ◽  
Particle Mass ◽  
Missing Energy ◽  
Mass Measurements ◽  
Focus Point

scholarly journals Nuclear mass measurements with radioactive ion beams

2019 ◽  
Vol 28 (04) ◽  
pp. 1930005 ◽  
Author(s):  
Michael A. Famiano
Keyword(s):  
Mass Measurement ◽  
Measurement Techniques ◽  
Nuclear Mass ◽  
Mass Measurements ◽  
Future Directions ◽  
Advantages And Disadvantages ◽  
Nuclear Masses ◽  
Under Construction ◽  
Very High ◽  
Practical Constraints

Nuclear masses are the most fundamental of all nuclear properties, yet they can provide a wealth of knowledge, including information on astrophysical sites, constraints on existing theory, and fundamental symmetries. In nearly all applications, it is necessary to measure nuclear masses with very high precision. As mass measurements push to more short-lived and more massive nuclei, the practical constraints on mass measurement techniques become more exacting. Various techniques used to measure nuclear masses, including their advantages and disadvantages are described. Descriptions of some of the world facilities at which the nuclear mass measurements are performed are given, and brief summaries of planned facilities are presented. Future directions are mentioned, and conclusions are presented which provide a possible outlook and emphasis on upcoming plans for nuclear mass measurements at existing facilities, those under construction, and those being planned.

scholarly journals Detecting kinematic boundary surfaces in phase space: particle mass measurements in SUSY-like events

2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Dipsikha Debnath ◽  
James S. Gainer ◽  
Can Kilic ◽  
Doojin Kim ◽  
Konstantin T. Matchev ◽  
...  
Keyword(s):  
Phase Space ◽  
Particle Mass ◽  
Mass Measurements ◽  
Boundary Surfaces

Online Nanoparticle Mass Measurement by Combined Aerosol Particle Mass Analyzer and Differential Mobility Analyzer: Comparison of Theory and Measurements

2009 ◽  
Vol 43 (11) ◽  
pp. 1075-1083 ◽  
Author(s):  
Cary Presser ◽  
Xiaofei Ma ◽  
Suvajyoti Guha ◽  
George W. Mulholland ◽  
Michael R. Zachariah
Keyword(s):  
Aerosol Particle ◽  
Mass Measurement ◽  
Particle Mass ◽  
Mass Analyzer ◽  
Differential Mobility Analyzer ◽  
Differential Mobility

scholarly journals Characterization of a catalyst-based conversion technique to measure total particulate nitrogen and organic carbon and comparison to a particle mass measurement instrument

2018 ◽  
Vol 11 (5) ◽  
pp. 2749-2768 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Agnieszka Kupc ◽  
Bartłomiej Witkowski ◽  
Ranajit K. Talukdar ◽  
Yong Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Gas Phase ◽  
Mass Measurement ◽  
Single Component ◽  
Particle Mass ◽  
Negative Ion ◽  
Ionization Source ◽  
Particulate Nitrogen ◽  
Esi Ms

Abstract. The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen-containing particles impact atmospheric chemistry, air quality, and ecological N deposition. Instruments that measure total reactive nitrogen (Nr = all nitrogen compounds except for N2 and N2O) focus on gas-phase nitrogen and very few studies directly discuss the instrument capacity to measure the mass of Nr-containing particles. Here, we investigate the mass quantification of particle-bound nitrogen using a custom Nr system that involves total conversion to nitric oxide (NO) across platinum and molybdenum catalysts followed by NO−O3 chemiluminescence detection. We evaluate the particle conversion of the Nr instrument by comparing to mass-derived concentrations of size-selected and counted ammonium sulfate ((NH4)2SO4), ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), sodium nitrate (NaNO3), and ammonium oxalate ((NH4)2C2O4) particles determined using instruments that measure particle number and size. These measurements demonstrate Nr-particle conversion across the Nr catalysts that is independent of particle size with 98 ± 10 % efficiency for 100–600 nm particle diameters. We also show efficient conversion of particle-phase organic carbon species to CO2 across the instrument's platinum catalyst followed by a nondispersive infrared (NDIR) CO2 detector. However, the application of this method to the atmosphere presents a challenge due to the small signal above background at high ambient levels of common gas-phase carbon compounds (e.g., CO2). We show the Nr system is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation using single-component, laboratory-generated, Nr-containing particles below 2.5 µm in size. In addition we show agreement with mass measurements of an independently calibrated online particle-into-liquid sampler directly coupled to the electrospray ionization source of a quadrupole mass spectrometer (PILS–ESI/MS) sampling in the negative-ion mode. We obtain excellent correlations (R2 = 0.99) of particle mass measured as Nr with PILS–ESI/MS measurements converted to the corresponding particle anion mass (e.g., nitrate, sulfate, and chloride). The Nr and PILS–ESI/MS are shown to agree to within ∼ 6 % for particle mass loadings of up to 120 µg m−3. Consideration of all the sources of error in the PILS–ESI/MS technique yields an overall uncertainty of ±20 % for these single-component particle streams. These results demonstrate the Nr system is a reliable direct particle mass measurement technique that differs from other particle instrument calibration techniques that rely on knowledge of particle size, shape, density, and refractive index.

Time Resolved Characterization of Diesel Particulate Emissions. 1. Instruments for Particle Mass Measurements

2001 ◽  
Vol 35 (4) ◽  
pp. 781-787 ◽  
Author(s):  
H. Moosmüller ◽  
W. P. Arnott ◽  
C. F. Rogers ◽  
J. L. Bowen ◽  
J. A. Gillies ◽  
...  
Keyword(s):  
Particle Mass ◽  
Particulate Emissions ◽  
Mass Measurements ◽  
Time Resolved ◽  
Diesel Particulate

scholarly journals Characterization of a catalyst-based total nitrogen and carbon conversion technique to calibrate particle mass measurement instrumentation

2018 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Agnieszka Kupc ◽  
Bartlomiej Witkowski ◽  
Ranajit K. Talukdar ◽  
Yong Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Atmospheric Chemistry ◽  
Platinum Catalyst ◽  
Mass Measurement ◽  
Ammonium Oxalate ◽  
Single Component ◽  
Particle Mass ◽  
Negative Ion ◽  
Ionization Source ◽  
Esi Ms

Abstract. The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen (N)-containing particles impact atmospheric chemistry, air quality, and ecological N-deposition. Instruments that measure total reactive nitrogen (Nr = all nitrogen compounds except for N2 and N2O) focus on gas-phase nitrogen and very few studies directly discuss the instrument capacity to measure the mass of Nr–containing particles. Here, we investigate the mass quantification of particle-bound nitrogen using a custom Nr system that involves total conversion to nitric oxide (NO) across platinum and molybdenum catalysts followed by NO-O3 chemiluminescence detection. We evaluate the particle conversion of the Nr instrument by comparing to mass derived concentrations of size-selected and counted ammonium sulfate ((NH4)2SO4), ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), sodium nitrate (NaNO3), and ammonium oxalate ((NH4)2C2O4) particles determined using instruments that measure particle number and size. These measurements demonstrate Nr-particle conversion across the Nr catalysts that is independent of particle size with 98 ± 10 % efficiency for 100–600 nm particle diameters. We also show conversion of particle-phase organic carbon species to CO2 across the instrument’s platinum catalyst followed by a non-dispersive infrared (NDIR) CO2 detector. We show the Nr system is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation using single component, laboratory generated, Nr-containing particles below 2.5 µm in size. In addition we show agreement with mass measurements of an independently calibrated on-line particle-into-liquid sampler directly coupled to the electrospray ionization source of a quadrupole mass spectrometer (PILS-ESI/MS) sampling in the negative ion mode. We obtain excellent correlations (R2 = 0.99) of particle mass measured as Nr with PILS-ESI/MS measurements converted to the corresponding particle anion mass (e.g. nitrate, sulfate, and chloride). The Nr and PILS-ESI/MS are shown to agree to within ~ 6 % for particle mass loadings up to 120 µg m−3. Consideration of all the sources of error in the PILS-ESI/MS technique yields an overall uncertainty of ±20 % for these single component particle streams. These results demonstrate the Nr system is a reliable direct particle mass measurement technique that differs from other particle instrument calibration techniques that rely on knowledge of particle size, shape, density, and refractive index.

scholarly journals Comparative sensitivities and specificities of the mass measurements of CK-MB2, CK-MB, and myoglobin for diagnosing acute myocardial infarction

1996 ◽  
Vol 42 (9) ◽  
pp. 1454-1459 ◽  
Author(s):  
J P Laurino ◽  
E W Bender ◽  
N Kessimian ◽  
J Chang ◽  
T Pelletier ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Clinical Utility ◽  
Mass Measurement ◽  
Mass Measurements ◽  
Time Points ◽  
Upper Limit ◽  
Creatine Kinase Mb ◽  
Sensitivity Specificity ◽  
Q Wave

Abstract We evaluated the clinical utility of the mass measurement of the tissue isoform of creatine kinase MB isoenzyme (CK-MB2) in the diagnosis of an acute myocardial infarction (AMI) by determining its sensitivity, specificity, and predictive value relative to those of CK-MB mass and myoglobin. Samples were obtained at 0, 4, 8, and 16 h postpresentation from 100 patients (41% with AMI). The order of sensitivity for the sample proportions taken at 0-2 h from the onset of symptoms was myoglobin > CK-MB2 > CK-MB. At all other time points, the sensitivity of CK-MB2 either equaled or surpassed that of both CK-MB and myoglobin, although the 95% confidence intervals for the population proportions each of these markers overlapped. Of the 41 AMI patients, 31 (76%) exhibited concurrent abnormal increases of CK-MB and %CK-MB2; the other 10 (24%; 8 non-Q wave, 2 Q wave) exhibited abnormal values for %CK-MB2 before their CK-MB exceeded the upper limit of normal. The specificity of myoglobin was statistically lower than that for either CK-MB2 or CK-MB at all time points.

High precision particle mass measurements using the KEDR detector at the VEPP-4M collider

2014 ◽  
Vol 184 (1) ◽  
pp. 75-88
Author(s):  
Evgeny B. Levichev ◽  
Aleksandr N. Skrinskii ◽  
Yuri A. Tikhonov ◽  
Korneliy Yu. Todyshev
Keyword(s):  
High Precision ◽  
Particle Mass ◽  
Mass Measurements
Sign in / Sign up

Export Citation Format

Share Document