scholarly journals Supersymmetric particle mass measurement with the boost-corrected contransverse mass

2010 ◽  
Vol 2010 (3) ◽  
Author(s):  
Giacomo Polesello ◽  
Daniel R. Tovey
Keyword(s):  
Mass Measurement ◽  
Particle Mass ◽  
Supersymmetric Particle

scholarly journals Supersymmetric particle mass measurement with invariant mass correlations

2009 ◽  
Vol 2009 (04) ◽  
pp. 084-084 ◽  
Author(s):  
Davide Costanzo ◽  
Daniel R Tovey
Keyword(s):  
Invariant Mass ◽  
Mass Measurement ◽  
Particle Mass ◽  
Supersymmetric Particle

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.

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 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.

Continuous particle mass measurement by recording the pressure drop in nuclepore filters

1998 ◽  
Vol 29 ◽  
pp. S1183-S1184
Author(s):  
Constantinos Sioutas ◽  
Petros Koutrakis ◽  
Pen-Yau Wang ◽  
Peter Babich ◽  
Jack M. Wolfon
Keyword(s):  
Pressure Drop ◽  
Mass Measurement ◽  
Particle Mass ◽  
Continuous Particle

scholarly journals Landscape of supersymmetric particle mass hierarchies in deflected mirage mediation

2012 ◽  
Vol 127 (1) ◽  
Author(s):  
B. Altunkaynak ◽  
B. D. Nelson ◽  
L. L. Everett ◽  
Y. Rao ◽  
I. -W. Kim
Keyword(s):  
Particle Mass ◽  
Supersymmetric Particle ◽  
Deflected Mirage Mediation
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