4 edition of Particle size distributions of aerosols generated in the hydriding of uranium found in the catalog.
Particle size distributions of aerosols generated in the hydriding of uranium
by National Library of Canada = Bibliothèque nationale du Canada in Ottawa
Written in English
|Series||Canadian theses = Thèses canadiennes|
|The Physical Object|
|Pagination||1 microfiche : negative.|
Preetha S Pillai, a Moorthy, Aerosol mass-size distributions at a tropical coastal environment: response to mesoscale and synoptic processes, Atmospheric Environment, /S(01), 35, 24, (), (). Animal data support that uranium absorption is a function of particle size and solubility, but when aerosols of purified uranium compounds were tested, greater absorption was observed. Animal data on deposition and absorption in the lung indicate large species differences (Spoor and Hursh, ; Voegtlin and Hodge, ).
Simulation of particle size distribution with a global aerosol model: Contribution of nucleation to aerosol and CCN number concentrations Fangqun Yu and Gan Luo Atmospheric Sciences Research Center, State University of New York, Fuller Road, Albany, New York , USA Abstract. An advanced particle microphysics model with a number of. During measurement of particle size, dimension like. a) Martin diameter: Length of the line that bisects the particle (irregular) image. b) Ferrets diameter also called as an end to end measurement. Are used to note the size of particles in microscopy. This method is used for particle size analysis in suspensions, aerosols and emulsions.
x of a size distribution p(x) is the square root of the variance (15), ˙ x = p ˙2 x (17) ˙ x has units of [m]. For standard aerosol and cloud size distributions, ˙ x is an ugly expression. Therefore many authors prefer to work with alternate deﬁnitions of standard deviation. Unfortu-nately, nomenclature for these alternate deﬁnitions is. The powder that is produced is of interest because its properties will affect the quality of the pellets that are produced from it. Full powderization of uranium metal pieces is desired, and the size distribution of particles is of particular interest. Previous work by Bloch and by Condon found particle .
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Aerosol Size Range Particle size is often determined by the process that generated the particle. Combustion particles usually start out in the Pm size range, but combine with each other (agglomerate) to form larger particles. Powder is broken down into smaller particles and released into the air; it is difficult to break down such.
The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing depleted uranium from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluated particle size distributions.
Aerosol particle size distribution is an important parameter that influences. The aerosol particle size distributions of uranium and its daughter products were studied and determined in the area of the Rožná mine, which is the last active uranium Cited by: 2.
Pelletizing workshop - aerosol size distribution and elemental composition. The INCAFeature software was used to determine particle size distribution and elemental composition of aerosols at the pelletizing workshop (Sampling 4) by automatically scanning Cited by: 1.
12 Early studies of depleted uranium aerosol exposure assumed that uranium combustion product particles would quickly settle out of the air 72 and thus could not affect populations more than a few.
High deposition also occurs for particles of about nm (6 [tin) diameter. The minimum deposition is about 2% at nm. The figure pertains to the case of `light exercise with mouth breathing'. This paper addresses one of the recommendations of the NRC report, namely to develop better information on the particle size of uranium mine aerosols.
The size distribution of radioactive aerosols containing radon progeny was measured by RPPSS (Radon Progeny Particle Size Spectrometer) with the measuring size. Showing the change in particle size for uranium and uranium hydride (UH 3) powder after successive hydriding-dehydriding sessions at (a) °C and (b) °C.
The arrows signify the sequence of the reactions with A → B → C indicating the Hydriding → Dehydriding → Hydriding step. Figure 5: Illustration of the D[4,3] and D[3,2] on a particle size distribution where a significant proportion of fines are present.
Percentiles For volume weighted particle size distributions, such as those measured by laser diffraction, it is often convenient to report parameters based upon the maximum.
Measurements of the Size Distribution of Aerosols Produced by Ultrasonic Humidification C. Rodes, T. Smith, R. Crouse, and G. Ramachandran Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, NC Aerosol number and mass distributions produced by an.
particle size distributions to some extent deviating from the expected lognormal distribution, possibly indicating two 'families' of particles. The vast majority of the radioactive aerosols consist of uranium and oxygen, but at the bed furnace, % of the uranium aerosols contained fluorine.
Other uranium. Aerosols generated by accidents are being investigated to develop the source terms for these releases. The lower boundry accidental release event would be a free fall spill of powders or liquids in static air.
Experiments measured the mass airborne and particle size distribution of these aerosols as a function of source size and spill height. the particle size distribution are the mass me&an aerodynamic diameter (mmad) and the geometric standard deviation (u~).
An mmad is a statistical diameter above or below which half the total mass of the distribution occurs. Ugis an index of dispersity, ranging from U~= 1 when all particles are the same size to u~= 5 or more when there is a very.
Hence, annual limit on intake (ALI) value has to be calculated for the actual aerosol size distribution. Vishwa Prasad et al. measured aerosol size distributions in a uranium processing and fabrication facility and reported that the ALI value for the obtained aerosol size distribution is – times that of standard ICRP value.
Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between and microm and a large size mode. We retrieved the complete aerosol particle size distributions by merging size distributions measured using a scanning electron mobility spectrometer (Brechtel SEMS or TSI DMPS), an optical particle sizer (TSI OPS), and an aerodynamic particle sizer (TSI APS).
These measurements cover the range of particle sizes from μm to 20 μm. Aerosol size distribution. Figure 3 presents an example of the results obtained for the distribution of uranium aerosol's aerodynamic diameter, as measured in one of the sampling experiments near the process site of conversion of UO 3 into UF 4 powder.
The distribution had an activity median aerodynamic diameter (AMAD) of µm and a. Particle weathering rates are related to particle characteristics suchas specific surface area, size distribution, elemental composition, U oxidationstates and crystallographic structure. Learn why particle size is important, how to interpret particle size distribution calculations, result interpretation, setting specifications and more.
HORIBA's full line of particle characterization instruments are explained in detail as well as how to select the right particle size analyzer for your application. (b) Particle size distribution for the aerosols Figure 5 shows the relation between the penetra-tion fraction (N/N0 or A/A0) and the number of screens.
The geometric mean (rg) and standard deviation (σg) of the size distributions were obtained by a least-squares fitting from equations (1) and (2).
The solid lines represent the results of a. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time.
They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro.Request PDF | SEM/EDX characterization of uranium aerosols at a nuclear fuel fabrication plant | Detailed aerosol knowledge is essential in numerous applications, including risk assessment in.Depending on the size and distribution on the hydride particles, self-ignition can occur after an indeterminate length of exposure to air.
Such exposure poses risk of self-ignition of fuel debris in radioactive waste storage vaults. Uranium metal exposed to steam produces a mixture of uranium hydride and uranium dioxide.