The abbreviated impactor measurement concept is a potential improvement to the labor-intensive full-resolution cascade impactor methodology for inhaler aerosol aerodynamic particle size distribution (APSD) measurement by virtue of being simpler and therefore quicker to execute. At the same ...

The purpose of this study was to resolve an anomalously high measure of extra-fine particle fraction (EPF) determined by the abbreviated cascade impactor possibly relevant for human respiratory tract (AIM-HRT) in the experiment described in Part 1 of this two-part series, in which the relative precision of ...

The purpose of this study was to resolve an anomalously high measure of extra-fine particle fraction (EPF) determined by the abbreviated cascade impactor possibly relevant for human respiratory tract (AIM-HRT) in the experiment described in Part 1 of this two-part series, in which the relative precision of ...

The purpose of this study was to compare relative precision of two different abbreviated impactor measurement (AIM) systems and a traditional multi-stage cascade impactor (CI). The experimental design was chosen to provide separate estimates of variability for each impactor type. ...

The purpose of this study was to compare relative precision of two different abbreviated impactor measurement (AIM) systems and a traditional multi-stage cascade impactor (CI). The experimental design was chosen to provide separate estimates of variability for each impactor type. ...

... collected.). Abbreviations Weights and measures should follow the International System of Units (SI), and such abbreviations should be used in ... ...

The counterflow virtual impactor (CVI) was used to measure condensed water content (liquid water and/or ice) on the DC-8 during NAMMA. ...

Aug 13, 2001 ... Medium: Teflon Inlet type: Impactor--direct Laboratory ...... Field sampling or measurement principle: Impactor Medium: Teflon Inlet type: ...

A procedure is described for fitting multimodal log-normal size distributions to cascade impactor data. he method was tested by applying it to published cascade impactor measurements for ammonium and nitrate that were previously analyzed by procedures that do not assume a functio...

Many analyses of impact events attempt to solve an inverse problem: Given the result, what was the impactor? One common example is the use of careful measurements of impact melt with the hope of deducing the impactor size and velocity.

... be written in italics. Abbreviations Use the decimal metric system for all measurements. Abbreviate units of measure when ... ...

This paper compares the collection characteristics of a new rotating impactor for ultra fine aerosols (FLB) with the industry standard (Hock). The volume and droplet size distribution collected by the rotating impactors were measured via spectroscopy and microscopy. The rotary impactors were co-lo...

... Abstract : The USSR translation describes systematic aerosol measurements taken in the surface layer by means of an impactor, Sholtz counter ...

The report provides useful tools for obtaining particle size distributions and graded penetration data from cascade impactor measurements. The programs calculate impactor aerodynamic cut points, total mass collected by the impactor, cumulative mass fraction less than for each sta...

Over the lifecycle of an orally inhaled product (OIP), multi-stage cascade impactor (CI) measurements are used for different purposes and to address different questions. Full-resolution CIs can provide important information during product development and are widely used but are time- and resource-intensive, highly variable, and suboptimal for OIP quality ...

... The particle loss mechanisms are discussed and improvements are suggested to reduce the loss. ... measurement of spherical particles and shape ...

... are concentrated by a virtual impactor at ... channel zero which represents non- fluorescent particles. Particle numbers in channel 1 represent noise ...

Particle size measurements by a prototype in-stack optical particle size monitor are compared to concurrent particle size measurements by an in-stack cascade impactor at three coal-fired fly ash sources. The results indicate that the optical monitor and impactor size measurements...

The report discusses three sets of experiments which demonstrate that a cascade impactor sampling a charged aerosol may yield a particle size distribution measurement that deviates from the time distribution. The distributions indicated more large particles and fewer small partic...

We discuss implications for secondary cratering and evolution of the external impactor population from lunar impact crater size-frequency distributions. We also present an assessment of human variation in crater identification and measurement.

The report provides a tutorial on the use of cascade impactors to measure the particle-size distribution of particulate matter at stationary industrial sources, and is Attachment No. 1 to the Project Final Report. The Project Final Report describes the ev...

To achieve automatic operation, the Quartz Crystal Microbalance (QCM) technique was applied to the measurement of collected mass. The sensisivity of QCM is good for large particles but rather poor for submicrometer particles. Inertial impactors are widely...

The MRI in-stack virtual impactor is a unique instrument that can provide real-time continuous measurements of stack aerosol particle-size distributions and can simultaneously provide size-segregated samples for morphological or chemical analysis.

This article compares the collection characteristics of a new rotating impactor Florida Latham Bonds (FLB) sampler for ultrafine aerosols with a mimic of the industry standard (Hock-type). The volume and droplet-size distribution collected by the rotating...

Multiple jet impactors are routinely used to measure airborne microbial concentrations in a variety of work and residential environments. nalyses of data collected with these units, however, should account for the possibility of multiple impactions at single sites. ata are usuall...

Andersen Mark-II and California Measurements PC-2 quartz-crystal (QCM) cascade impactors have been calibrated with monodisperse aerosol particles. Both the Andersen and QCM impactors were determined to be reliable instruments: the advantage of the QCM imp...

Virtual impactors are currently being used in a number of instruments to separate an aerosol into different size ranges. The virtual impactor is a variation of the standard impactor in which the impaction surface is replaced by an orifice into which particles can pass and be collected or counted. We have made an experimental study of ...

Studies on the jet-to-slide distance which affects the sharpness of classification, and on wall-to-slide distance which affects the loss of particles on the wall were emphasized particularly. An improved cascade impactor containing round jets and slides was designed and calibrated. Problems encountered in the calibratpon process were studied and solved. Studies of ...

Fabrication of compositionally graded structures for use as light-gas gun impactors has been demonstrated using a tape casting technique. Mixtures of metal powders in the Mg-Cu system were cast into a series of 19 tapes with uniform compositions ranging from 100% Mg to 100% Cu. The individual compositions were fabricated into monolithic pellets for characterization of ...

The paper discusses the development and testing of a cyclone precollector for cascade impactors and a dual-cyclone system. These devices will be used to measure the concentration of inhalable particles in process streams....

Cascade impaction is a standard test method for characterizing the quality of inhalable drug products. The sizes of the nozzles on each stage of the impactor are the critical dimensions for the performance of the impactor. Compendial reference methods call for periodic measurement of the size of the nozzles on each stage, a procedure ...

...of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Program General Provisions § 72.3 Measurements, abbreviations, and acronyms. Measurements,...

CAMEX-4 CVI CLOUD CONDENSED WATER CONTENT V1 ... The counterflow virtual impactor (CVI) was used to measure condensed water content (liquid water or ice in ...

... of dilution samplers with advanced measurement techniques for composition ... the cascade impactor and aerosol time-of-flight mass spectrometer ...

The authors present results of a large number of terrestrial measurements in the USSR of the concentrations and spectral distributions of natural aerosols at various times of the year, obtained with the aid of an impactor.

The counterflow virtual impactor (CVI) was used to measure condensed water content (liquid water or ice in particles about 8 microns in diameter and up) and ...

The counterflow virtual impactor (CVI) was used to measure condensed water content (liquid water or ice in particles about 8 microns in diameter and up) and ...

... back to the atmosphere nearly the same particle ... virtual impactor (CVI) which was also a part ... is a discriminating sampler which allows only particles ...

If a dust current is blown out of a nozzle and collides with a flat plate, particles larger than a certain dimension will collide with and be captured by the flat plate, and particles smaller than that will entrain an air current and go astray without colliding with the flat plate. It is therefore possible to measure particle size distribution with the use of a set of ...

The size distribution of dust particles suspended in the atmosphere near the ground which carry the naturally occurring radioactive substances was studied by the cascade impactor and autoradiography, i.e., the cascade impactor was used for classifying the dust particles into 4 groups by their particle sizes, and the autoradiography was used for ...

An interactive computer resource for analyzing, evaluating, and archiving particle size distributions as determined by cascade impactors for environmental measurement is described. The Particle Data Reduction (PADRE) computer program assists users in obtaining high quality size-mass distribution data for archival in the Fine Particle Emissions Information ...

Abstract Regional strain-based brain injury intensity during controlled cortical impact (CCI) was studied using a three-dimensional numerical rat brain model. A full factorial design of CCI computer experiments was performed using two typical impactor shapes (flat or hemispherical) at a fixed impact velocity of 4?m/s with various impact depths (1, 1.5, 1.6, 2, 2.5, 2.7, and ...

Measurements have been made on a dichotomous virtual impactor developed by the Environmental Research Corporation. The object was to study the feasibility of employing the virtual impaction scheme in air samplers to collect size fractionated particle samples for subsequent x-ray fluorescence analysis. The size separation characteristics and ...

Particle size measurements by a prototype in-stack optical particle size monitor are compared to concurrent particle size measurements by an in-stack cascade impactor at three coal-fired fly ash sources. The results indicate that the optical monitor and i...

Consists of multiple items that measure a single domain such as fatigue. Standard error of measurement (SEM) Describes an expected obse rved score fluctuation due to error in the measurement tool.

Aircraft sampling results and direct measurements of atmospheric aerosol concentrations and particle size distributions are presented and discussed. An impactor, which allows particle number measurement for particles above 0.5 micrometer and particle size...

...definitions, abbreviations and methods of analysis set forth in 40 CFR part 401 shall apply to this subpart. (b) The abbreviation �mpc� shall mean 1000 pieces of floor tile. (c) The term �pieces� shall mean floor tile measured in the standard size of...

For measurements of ore dust in uranium concentrating mills, a Sierra Model 235 slotted cascade impactor was calibrated at a flow rate of .21 m exp 3 /min, using solid monodisperse particles and an impaction surface of Whatman No. 41 filter paper soaked i...

The validity of the stratospheric aerosol measurements made by the satellite sensors SAM II and SAGE was tested by comparing their results with each other and with results obtained by other techniques (lider, dustsonde, filter, and impactor). The latter t...

The proceedings consist of 17 papers on improved instruments and techniques for sampling and measuring particulate emissions and aerosols; e.g., cascade impactors, cyclone collectors, and diffusion-battery/nuclei-counter combinations. Transmissometers and instruments for measurin...

The USSR translation describes systematic aerosol measurements taken in the surface layer by means of an impactor, Sholtz counter and filters FPP-18. The preliminary processing of results showed that there are mainly two types of distributions of aerosol ...

Students work in small groups to read a recipe involving fractions, halve the recipe's values, and make a batch of fudge. The importance of selection of appropriate measuring tools is taught. Abbreviations for capacity measuring tools are reviewed.

Apr 21, 2011 ... Data Set Name, Femur Measurements, Research Animal Holding Facility ... Spreadsheet Abbreviation Key: femur measurements of Delayed Flight ...

A simultaneous PVDF/VISAR measurement technique was used for isentropic-loading experiments with a polymethyl methacrylate (PMMA) specimen. The experiments used a graded density impactor accelerated onto a tantalum driver backed with PMMA and then lithium fluoride windows for each experiment. Simultaneous measurements made at each ...

Aluminum is a standard material for shock wave experiments. The increased velocity of our two-stage light-gas gun has been used to extend the range of previous aluminum measurements in order to reduce the gap between laboratory data and the data obtained with the nuclear driven shock impedance match methods. The experiments reported include direct collision Hugoniot ...

Cascade impactor analysis is the standard technique for in vitro characterization of aerosol clouds generated by medical aerosol generators. One important reason for using this inertial separation principle is that drug fractions are classified into aerodynamic size ranges that are relevant to the deposition in the respiratory tract. Measurement of these ...

Pharmaceutical aerosol size distribution analysis based on multi-stage inertial impaction is well accepted, though laborious. The TSI 3306 Impactor Inlet/3321 time-of-flight (TOF) Aerodynamic Particle Size Analyzer (APS) has been evaluated for its ease of use and potential for time savings during product development. However, instrument inlet modifications may be necessary for ...

Inertial impaction is generally regarded as the 'gold standard' for the in vitro assessment of aerodynamic deposition of inhaled formulations. Despite the availability of several impactors, few studies have compared measurements of aerodynamic deposition using multiple impactors and none employed a combination formulation. The ...