Spark-Source Mass Spectroscopy

1967 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Edward B. Owens
Keyword(s):  
Quantitative Data ◽  
Energy Spectra ◽  
Optimum Conditions ◽  
Relative Volatility ◽  
Analytical Error ◽  
Diffusion Rates ◽  
Plate Calibration ◽  
Photographic Emulsions ◽  
And Diffusion ◽  
Spark Source Mass Spectroscopy

This paper is a review presenting a description of the instrument and method, a brief summary of the early work, and a more detailed look at the development since 1960. Studies on the properties of photographic emulsions as ion detectors and the optimum conditions for their use are reported. Various methods are reported for quantitative data treatment, which include plate calibration, photometry, and corrections. Investigations of the spark source are reviewed, covering the causes and effects of the varying energy spectra and some corrections for the relative volatility and diffusion rates. The contribution of the sample itself to the analytical error is discussed, and the results obtained with rigorous standardization are presented.

Absorption and Diffusion Rates of Hydrogen in "TiMn2"

1981 ◽  
Vol 72 (4) ◽  
pp. 238-243
Author(s):  
Minoru Arita ◽  
Nobuhiro Takashima ◽  
Yukio Ichinose ◽  
Mayumi Someno
Keyword(s):  
Diffusion Rates ◽  
And Diffusion

scholarly journals Tensile Behavior and Diffusion of Moisture through Flax Fibers by Desorption Method

2019 ◽  
Vol 11 (13) ◽  
pp. 3558 ◽  
Author(s):  
Swarda S. Radkar ◽  
Ali Amiri ◽  
Chad A. Ulven
Keyword(s):  
Diffusion Coefficients ◽  
Natural Fibers ◽  
Woven Fabrics ◽  
Tensile Behavior ◽  
Flax Fiber ◽  
Additional Absorption ◽  
Flax Fibers ◽  
Diffusion Rates ◽  
Desorption Method ◽  
And Diffusion

There has been a substantial increase in the usage of natural fibers and biodegradable polymers in composite materials due to the recent focus on sustainability of materials. Flax fibers have exhibited higher mechanical properties compared to most other natural fibers available. However, one of the major challenges faced in the use of flax fiber is its hydrophilicity. In this study, the tensile behavior of flax fiber tows removed from commercially available woven fabrics were investigated at different moisture levels. The breaking tenacity of fiber tows was shown to increase with an increase in moisture content of up to 25%. After this point, additional absorption of moisture resulted in a decrease of fiber tenacity. In addition, the diffusion process through flax fiber mat with different areal densities was investigated and the diffusion coefficients were determined using the desorption curves. Diffusion rates were not found to significantly change with varying areal densities of 200 to 400 gsm, but were significantly different when exposed to temperatures of 55 °C versus 80 °C.

scholarly journals Relative humidity-dependent viscosity of secondary organic material from toluene photo-oxidation and possible implications for organic particulate matter over megacities

2016 ◽  
Author(s):  
M. Song ◽  
P. F. Liu ◽  
S. J. Hanna ◽  
R. A. Zaveri ◽  
K. Potter ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Diffusion Coefficients ◽  
Organic Material ◽  
Organic Molecules ◽  
Mixing Times ◽  
Organic Particulate Matter ◽  
Photo Oxidation ◽  
Diffusion Rates ◽  
And Diffusion

Abstract. To improve predictions of air quality, visibility, and climate change, knowledge of the viscosities and diffusion rates within organic particulate matter consisting of secondary organic material (SOM) is required.Most qualitative and quantitative measurements of viscosity and diffusion rates within organic particulate matter have focused on SOM particles generated from biogenic VOCs such as α-pinene and isoprene. In this study, we quantify the relative humidity (RH)-dependent viscosities at 295 ± 1 K of SOM produced by photo-oxidation of toluene, an anthropogenic VOC. The viscosities of toluene-derived SOM were 2 × 10−1 to ∼6 × 106 Pa·s from 30 to 90 % RH, and greater than ~2 × 108 Pa·s (similar to or greater than the viscosity of tar pitch) for RH ≤ 17 %. These viscosities correspond to Stokes-Einstein-equivalent diffusion coefficients for large organic molecules of ~2 × 10−15 cm2·s−1 for 30 % RH, and lower than ~3 × 10−17 cm2·s−1 for RH ≤ 17 %. Based on these estimated diffusion coefficients, the mixing time of large organic molecules within 200 nm toluene-derived SOM particles is 0.1–5 hr for 30 % RH, and higher than ~100 hr for RH ≤ 17 %. These results were used, as a first-order approximation, to estimate if organic particulate matter will be in well-mixed over the world's top 15 most populous megacities. If the organic particulate matter in the megacities is similar to the toluene-derived SOM in this study, in Kolkata, Istanbul, Dhaka, Tokyo, Shanghai, and Mumbai, mixing times in organic particulate matter during extended periods of the year will be very short, and well-mixed particles can be assumed. On the other hand, the mixing times of large organic molecules in organic particulate matter in Delhi, Beijing, Mexico City, Cairo, and Karachi may be long and the particles may not be well-mixed in the afternoon (3:00–5:00 local time) during certain times of the year.

ChemInform Abstract: ABSORPTION AND DIFFUSION RATES OF HYDROGEN IN TITANIUM-MANGANESE (TIMN2)

1981 ◽  
Vol 12 (30) ◽  
Author(s):  
M. ARITA ◽  
N. TAKASHIMA ◽  
Y. ICHINOSE ◽  
M. SOMENO
Keyword(s):  
Diffusion Rates ◽  
And Diffusion

Radar Backscatter from Underdense Meteors and Diffusion Rates

2008 ◽  
Vol 102 (1-4) ◽  
pp. 403-409 ◽  
Author(s):  
Werner Singer ◽  
Ralph Latteck ◽  
Luis Federico Millan ◽  
Nick J. Mitchell ◽  
Jens Fiedler
Keyword(s):  
Radar Backscatter ◽  
Diffusion Rates ◽  
And Diffusion

A STUDY OF THE Be9(He3, n)C11 REACTION

1963 ◽  
Vol 41 (7) ◽  
pp. 1036-1046 ◽  
Author(s):  
L. van der Zwan ◽  
A. T. Stewart ◽  
J. Y. Park ◽  
E. Merzbacher
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Particle Energy ◽  
Energy Spectra ◽  
Angular Distributions ◽  
Proton Recoil ◽  
The Cross ◽  
Photographic Emulsions

The energy spectra and angular distributions of the emergent neutrons from the Be9(He3, n)C11 reaction have been obtained for an incident He3-particle energy of 2 Mev with the technique of observing proton recoil in photographic emulsions. The cross sections were normalized to Be9(He3, p)B11 data observed simultaneously at 90° to the beam. The lack of similarity in the (He3, n) and (He3, p) mirror reactions to some residual states suggests a direct interaction mechanism rather than compound nucleus. An attempt to analyze some of the data in terms of double particle stripping has been made.

scholarly journals Nuclear disintegrations produced by cosmic rays

1949 ◽  
Vol 196 (1046) ◽  
pp. 325-343 ◽  
Keyword(s):  
Cosmic Radiation ◽  
High Energy ◽  
Energy Spectra ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Wide Range ◽  
High Energy Tail ◽  
Energy And Angular Distributions ◽  
Photographic Emulsions ◽  
Α Particles

Measurements have been made on the energy and angular distributions of the charged particles from disintegration ‘stars’ produced in the silver and bromine nuclei of photographic emulsions exposed to cosmic radiation. The observations extended over a wide range of excitation energies (100 to 700 MeV). The energy spectra and angular distributions of the protons can be explained in all cases by simple evaporation theory. This energy distribution shows also a high-energy tail consisting of direct knock-on protons and slow mesons. At high excitation energies the α-particles exhibit collimation effects which are probably due to localized ‘boiling’ or a form of fission.

New Insights into the Generation Mechanism of Quasicrystal by the Surface Reaction Between Ultrafine Particles and Deposited Clusters

2003 ◽  
Vol 10 (02n03) ◽  
pp. 461-466 ◽  
Author(s):  
O. Kido ◽  
C. Kaito ◽  
Y. Saito
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Ultrafine Particles ◽  
Surface Reaction ◽  
Generation Mechanism ◽  
Uniform Thickness ◽  
Microscope Images ◽  
Diffusion Rates ◽  
Al Thin Film ◽  
And Diffusion

On heating Mn-deposited Al particles (Mn–Al specimen) at 300°C, diffraction spots due to a Al86Mn14 quasicrystal appeared, in addition to those due to Al6Mn alloy. On heating a specimen of the Al-deposited Mn particles (Al–Mn specimen), Al50Mn50 alloy was formed. Neither the quasicrystal nor Al6Mn phases appeared. The electron microscope images of the Mn–Al specimen showed the existence of void clusters in the Al particles. This indicates that the alloys and the quasicrystals were produced by the diffusion of Al atoms to the Mn clusters. In the case of the Al–Mn specimen, the surface of Mn particles was covered with an Al thin film of uniform thickness. The surface Al layer changed to Al50Mn50 alloy. These results indicate that the diffusion direction of atoms and diffusion rates are different between Mn–Al and Al–Mn systems.

scholarly journals Compound Ejector Thrust Augmenter Development

1973 ◽  
Author(s):  
L. W. Throndson
Keyword(s):  
Wind Tunnel ◽  
Short Length ◽  
Primary Flow ◽  
Engine Thrust ◽  
Internal Aerodynamics ◽  
Diffusion Rates ◽  
Aircraft Application ◽  
Directing Attention ◽  
And Diffusion ◽  
Coanda Flow

The basic simplicity of ejectors provides an advantageous form of engine thrust augmentation for V/STOL aircraft. Application requires careful internal aerodynamics development to provide high augmentation ratios in compact, short length, ejector installations. Development of the compound ejector through rig and wind tunnel tests is described wherein Coanda flow and improved central primary flow injection are combined. Several methods of reducing ejector volume are employed through increased mixing and diffusion rates while directing attention to loss sources such as inlet blockage.

Root Growth and Diffusion Rates as Functions of Oxygen Concentration

1961 ◽  
Vol 25 (6) ◽  
pp. 463-467 ◽  
Author(s):  
L. H. Stolzy ◽  
J. Letey ◽  
T. E. Szuszkiewicz ◽  
O. R. Lunt
Keyword(s):  
Root Growth ◽  
Oxygen Concentration ◽  
Diffusion Rates ◽  
And Diffusion
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