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A photographic technique is described which overcomes many of the problems encountered in measuring the droplet size distribution in sprays. Droplet photographs were analysed using a Mullard Particle Size Analyser as recommended in the text and it is shown that, for photographs in which the depth of field is less than the spray thickness, a high contrast emulsion leads to errors. In general it is better to avoid out-of-focus drops, but a method is suggested which permits the results to be corrected provided the extent of the spray is large compared to the depth of field.

The location and size of particles within a volume which is stationary or dynamic can be found by two techniques of coherent optics. In the first technique the volume is illuminated with coherent light and the resulting diffraction patterns are recorded in the far-field (Frauhofer region) of the particles. The particle information is found from the resultant density variations on the film. In the second technique the developed negative (a Fraunhofer hologram) is illuminated with coherent light and the particle field is reconstructed in three dimensions. This investigation is an analysis of these two techniques and their relative merits. Because magnification is important in the second technique the methods of magnifying the volume are discussed. It is found that reconstructing the volume from the hologram yields particle information which is easier to obtain than the information resulting from the diffraction patterns. The volume is also found to be easily and uniformly magnified by an imaging lens in the reconstruction process.

The Spectrometric Oil Analysis Program (SOAP) is a maintenance system used by the Air Force for continuous monitoring of engine oil samples. Total mass concentrations of various metals are measured to provide an indication of engine wear and to warn of impending malfunction; such data provide a basis for scheduling maintenance action in advanced of failure. Supplementary methods of analysis are sought with the objective of characterizing oil samples more completely so as to sharpen SOAP decision criteria and achieve improvements in reliability and cost effectiveness. One such technique is particle counting, which defines the size distribution of wear-metal particles and other debris if present. This report describes exploratory work which establishes a methodology for particle-size analysis of authentic engine oils and shows how the data can be applied for practical decision making. Indications are that the engine failure rate can be reduced to about 16% of its current level by supplementing each spectrometric analysis with a particle count. Instrumentation and technique are susceptible to automation which would permit the necessary particle size analysis is to be made routinely in a SOAP laboratory within three minutes per sample. An approach to the problems of realizing and exploiting this potential is outlined. (Author)

The Spectrometric Oil Analysis Program (SOAP) is a maintenance system used by the Air Force for continuous monitoring of engine oil samples. Total mass concentrations of various metals are measured to provide an indication of engine wear and to warn of impending malfunction; such data provide a basis for scheduling maintenance action in advanced of failure. Supplementary methods of analysis are sought with the objective of characterizing oil samples more completely so as to sharpen SOAP decision criteria and achieve improvements in reliability and cost effectiveness. One such technique is particle counting, which defines the size distribution of wear-metal particles and other debris if present. This report describes exploratory work which establishes a methodology for particle-size analysis of authentic engine oils and shows how the data can be applied for practical decision making. Indications are that the engine failure rate can be reduced to about 16% of its current level by supplementing each spectrometric analysis with a particle count. Instrumentation and technique are susceptible to automation which would permit the necessary particle size analysis is to be made routinely in a SOAP laboratory within three minutes per sample. An approach to the problems of realizing and exploiting this potential is outlined. (Author)

The UrQMD transport model is used to study a system-size and energy dependence of the pion production in high energy collisions. New data of the NA61/SHINE Collaboration on spectra of negatively charged pions in proton-proton interactions at SPS energies are considered. These results are compared with the corresponding data of the NA49 Collaboration in central Pb+Pb collisions at the same collision energies per nucleon. Mean pion multiplicity per participant nucleon, inverse slope parameter of the transverse momentum spectra, and width of rapidity distribution are investigated. A role of isospin effects is discussed. We find that the UrQMD model predicts a non-monotonous behavior of mean transverse mass with collision energy for positively charged pions at the mid-rapidity in inelastic proton-proton interactions. This will be checked soon experimentally by NA61/SHINE Collaboration.

This technical report presents the results of an analytical research study performed at the U.S. Army Research Laboratory (ARL), Aberdeen Proving Ground (APG), MD. The focus of the work centers on the instrument setup and operation for performing particle size determinations on a polydispersed, camouflage paint conforming to the U.S. Department of the Army Military Specification MIL-C-53039A, Coating, Aliphatic Polyurethane, Single Component, Chemical Agent Resistant. The analyses are graphically displayed and are provided with a brief explanation summarizing the results. A short description of merited future work is also mentioned.

Recent advances and developments in the particle-sizing technologies are briefly reviewed in accordance with three operating principles including particle size and shape descriptions. Significant trends of the particle size analysing equipment recently developed show that compact electronic circuitry and rapid data processing systems were mainly adopted in the instrument design. Some newly developed techniques characterizing the particulate system were also introduced.

This study aims to evaluate the effects of omega-3 fatty acid supplementation on LDL particle size distribution and small dense LDL (sdLDL) levels. Utilizing a network meta-analysis of clinical trials, we will synthesize data to determine how omega-3 preparations influence various lipoprotein subfractions, specifically focusing on sdLDL and large LDL particles. Additionally, we will conduct exploratory analyses on triglycerides (TG) and high-density lipoprotein (HDL) levels

This study aims to evaluate the effects of omega-3 fatty acid supplementation on LDL particle size distribution and small dense LDL (sdLDL) levels. Utilizing a network meta-analysis of clinical trials, we will synthesize data to determine how omega-3 preparations influence various lipoprotein subfractions, specifically focusing on sdLDL and large LDL particles. Additionally, we will conduct exploratory analyses on triglycerides (TG) and high-density lipoprotein (HDL) levels

This study aims to evaluate the effects of omega-3 fatty acid supplementation on LDL particle size distribution and small dense LDL (sdLDL) levels. Utilizing a network meta-analysis of clinical trials, we will synthesize data to determine how omega-3 preparations influence various lipoprotein subfractions, specifically focusing on sdLDL and large LDL particles. Additionally, we will conduct exploratory analyses on triglycerides (TG) and high-density lipoprotein (HDL) levels

Surface areas were measured and scanning electron microscopy (SEM) photographs were obtained from seven boron particle samples used in recent boron particle combustion experiments. Some significant differences were seen between the manufacturer claimed particle sizes and the distributions obtained from the SEM photographs. In those samples with large particle size distributions, calculated surface areas differed significantly from measured surface areas and it is clear that a single particle diameter parameter is inadequate to describe the corresponding surface area of the true particle size distribution. In general, the particle size distribution estimates taken from SEM yield lower surface areas than were measured. Further data on the purity of the samples are necessary to determine whether the phase or purity of the boron particle has an effect on the efficiency of boron particle combustion.

The results of a multi-year research effort addressing fundamental scientific issues relevant to the application of laser diagnostic methods as on- line sensors in next-generation propulsion systems are summarized. The overall objective of this research effort was to contribute to the scientific knowledge base necessary to characterize and then extend the capabilities of near-forward scattering (laser-diffraction) particle sizing techniques in terms of application as intelligent sensors capable of on-line, autonomous, and self- diagnosing operation in hostile propulsion system environments. The project scope encompassed three research areas: (1) steering or deflection of the probe laser beam due to refractive index (temperature or concentration) gradients, (2) inverse scattering algorithms, and (3) multiple scattering and measurements in optically thick media. The important technical contributions of this project included: development and demonstration of a concept which allows on-line configuration of optimal detector arrays using transmission-mode spatial light modulators and which can obviate the beam steering problem; derivation of the optimal scaling law for Fraunhofer diffraction particle sizing systems which integrated the optical detector array geometry and the inversion software; systematic formulation and synthesis of the family of integral transform solutions to the inverse Fraunhofer diffraction particle sizing problem and development of a new integral transform; development of a radiation transfer model for near-forward scattering by optically-thick particle media; and development of a general solution and technique for solving the inverse scattering problem for optically-thick dispersions of particles large compared to the wavelength.

The results of a multi-year research effort addressing fundamental scientific issues relevant to the application of laser diagnostic methods as on- line sensors in next-generation propulsion systems are summarized. The overall objective of this research effort was to contribute to the scientific knowledge base necessary to characterize and then extend the capabilities of near-forward scattering (laser-diffraction) particle sizing techniques in terms of application as intelligent sensors capable of on-line, autonomous, and self- diagnosing operation in hostile propulsion system environments. The project scope encompassed three research areas: (1) steering or deflection of the probe laser beam due to refractive index (temperature or concentration) gradients, (2) inverse scattering algorithms, and (3) multiple scattering and measurements in optically thick media. The important technical contributions of this project included: development and demonstration of a concept which allows on-line configuration of optimal detector arrays using transmission-mode spatial light modulators and which can obviate the beam steering problem; derivation of the optimal scaling law for Fraunhofer diffraction particle sizing systems which integrated the optical detector array geometry and the inversion software; systematic formulation and synthesis of the family of integral transform solutions to the inverse Fraunhofer diffraction particle sizing problem and development of a new integral transform; development of a radiation transfer model for near-forward scattering by optically-thick particle media; and development of a general solution and technique for solving the inverse scattering problem for optically-thick dispersions of particles large compared to the wavelength.

Particle size distribution measurements of a variety of materials over a range from 0.1 to 150 microns are presented. Computer data analysis provides plots of the cumulative weight-size distribution and the mass frequency distribution. The size range covered was accomplished by two sedimentation methods both yielding the Stokesian diameter. Centrifugal photosedimentation was used for fine particles and gravity sedimentation for coarse particles. The useful range of particle concentrations in dispersions for conducting repeatable measurements was determined for both methods of sedimentation. Results of supplementary investigations by microscope on the particle shape of the materials analyzed and other pertinent data are listed in an appendix.

Particle size distribution measurements of a variety of materials over a range from 0.1 to 150 microns are presented. Computer data analysis provides plots of the cumulative weight-size distribution and the mass frequency distribution. The size range covered was accomplished by two sedimentation methods both yielding the Stokesian diameter. Centrifugal photosedimentation was used for fine particles and gravity sedimentation for coarse particles. The useful range of particle concentrations in dispersions for conducting repeatable measurements was determined for both methods of sedimentation. Results of supplementary investigations by microscope on the particle shape of the materials analyzed and other pertinent data are listed in an appendix.

The size and distribution of particles in a drilling fluid can impact fluid performance. You may need big solids for bridging or wellbore strengthening. Small particles might result in poor [...]

The size and distribution of particles in a drilling fluid can impact fluid performance. You may need big solids for bridging or wellbore strengthening. Small particles might result in poor [...]

We have performed a direct numerical simulation of dilute turbulent particulate flow in a vertical plane channel, fully resolving the phase interfaces. The flow conditions are the same as those in the main case of "Uhlmann, M., Phys. Fluids, vol. 20, 2008, 053305", with the exception of the computational domain length which has been doubled in the present study. The statistics of flow and particle motion are not significantly altered by the elongation of the domain. The large-scale columnar-like structures which had previously been identified do persist and they are still only marginally decorrelated in the prolonged domain. Voronoi analysis of the spatial particle distribution shows that the state of the dispersed phase can be characterized as slightly more ordered than random tending towards a homogeneous spatial distribution. It is also found that the p.d.f.'s of Lagrangian particle accelerations for wall-normal and spanwise directions follow a lognormal distribution as observed in previous experiments of homogeneous flows. The streamwise component deviates from this law presenting significant skewness. Finally, a statistical analysis of the flow in the near field around the particles reveals that particle wakes present two regions, a near wake where the velocity deficit decays as 1/x and a far wake with a decay of approximately 1/(x*x).

Pipette analysis and X-ray diffraction techniques were employed to characterize the particle size distribution and clay mineral content of the feldspar, calvert, ball, and jordan soils. In general, the ball, calvert, and jordan soils were primarily clay size particles composed of kaolinite and illite whereas the feldspar soil was primarily silt-size particles composed of quartz and feldspar minerals.

The deficiencies impeding the integration of laser diffraction particle sizing techniques into intelligent sensors for next generation propulsion systems have been identified. The research addressed three areas: inverse scattering algorithms; multiple scattering; and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. Direct integral transform techniques for the inverse problem have been formulated on a common basis and comprehensively evaluated. An error in the original derivation of the the method of Petrov has been corrected and a new integral transform solution has been developed. Concerning multiple scattering, a new synthesis of successive order and discrete ordinates models has been developed for predictions of near forward radiative transfer in optically thick media and the results have been verified with experimental data and an independent Monte Carlo simulation. Finally, a new concept involving programmable spatial filtering at the transform plane which allows annular detectors of variable geometries to be configured on line by an intelligent instrument has been proposed and proof of principle experiments have begun. The concept will permit a detector to be automatically reconfigured around the deflected beam center and also will allow adaptive grid methods to be incorporated into the inversion algorithms.

The deficiencies impeding the integration of laser diffraction particle sizing techniques into intelligent sensors for next generation propulsion systems have been identified. The research addressed three areas: inverse scattering algorithms; multiple scattering; and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. Direct integral transform techniques for the inverse problem have been formulated on a common basis and comprehensively evaluated. An error in the original derivation of the the method of Petrov has been corrected and a new integral transform solution has been developed. Concerning multiple scattering, a new synthesis of successive order and discrete ordinates models has been developed for predictions of near forward radiative transfer in optically thick media and the results have been verified with experimental data and an independent Monte Carlo simulation. Finally, a new concept involving programmable spatial filtering at the transform plane which allows annular detectors of variable geometries to be configured on line by an intelligent instrument has been proposed and proof of principle experiments have begun. The concept will permit a detector to be automatically reconfigured around the deflected beam center and also will allow adaptive grid methods to be incorporated into the inversion algorithms.

The deficiencies impeding the integration of laser diffraction particle sizing techniques into intelligent sensors for next generation propulsion systems have been identified. The research addressed three areas: inverse scattering algorithms; multiple scattering; and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. Direct integral transform techniques for the inverse problem have been formulated on a common basis and comprehensively evaluated. An error in the original derivation of the the method of Petrov has been corrected and a new integral transform solution has been developed. Concerning multiple scattering, a new synthesis of successive order and discrete ordinates models has been developed for predictions of near forward radiative transfer in optically thick media and the results have been verified with experimental data and an independent Monte Carlo simulation. Finally, a new concept involving programmable spatial filtering at the transform plane which allows annular detectors of variable geometries to be configured on line by an intelligent instrument has been proposed and proof of principle experiments have begun. The concept will permit a detector to be automatically reconfigured around the deflected beam center and also will allow adaptive grid methods to be incorporated into the inversion algorithms.

Measurement of the particle size of powders is important for many manufacturing operations. In the field of propellants it is also important since the particle size distribution of the ingredients significnantly affects not only the burning rate but also the sensitivity of the propellant. A method used to measrsue the particle size distribution of ammonium perchlorate and ammonium sulphate, common propellant chemicals, using a low angle light scattering technique is described.

Measurement of the particle size of powders is important for many manufacturing operations. In the field of propellants it is also important since the particle size distribution of the ingredients significnantly affects not only the burning rate but also the sensitivity of the propellant. A method used to measrsue the particle size distribution of ammonium perchlorate and ammonium sulphate, common propellant chemicals, using a low angle light scattering technique is described.

The fundamental scientific issues impeding the integrataion of laser diffraction particle sizing techniques into intelligent sensors for next generation propulsion systems have been identified. This research contributes to the knowledge base necessary to significantly advance the laser diffraction concept. The research addresses three areas, inverse scattering algorithms, multiple scattering, and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. Progress has been made in the development of direct integral transform techniques for the inverse problem which potentially can operate at frequencies on the order of 10 kHz as needed for propulsion system sensors.Adequate inversion performance on bi modal distributions with signal to noise ratios as low as 10% has been demonstrated. The multiple scattering problem has been formulated as a matrix operation, and a corresponding scheme for the inversion of diffraction data under multiple scattering conditions has been proposed. A prototype computer generated hologram which generates a hollow cone of scattered light has been fabricated. Experiments are underway to demonstrate the usefulness of this development to the inverse multiple scattering problem. Finally, a concept to allow laser diffraction particle sizing sensors to function autonomously in environments where transient beam deflections are significant has been proposed and proof of principle experiments have begun.

This report summarizes the results of a research program conducted to determine the characteristics and potential capabilities of particle size analysis using laser interferometer techniques. Theoretical and experimental analyses are reported which indicate that a range of particle sizes from submicron to millimeters in diameter can be determined when the cross-sectional shape of the particle is known. It is shown that number density can be determined from the interferometric measurements in certain restricted applications. The limitations and potentialities of this method for determining particle size are discussed in detail.

An evaluation was made of the Microtrac (SPA) to determine whether it would meet Atlantic Research Corporation needs for rapid analysis of superfine materials. In this size range, the Microtrac (SPA) proved to be as reproduciable as the MSA particle size analyzer. In most cases, particle size results of the Microtrac (SPA) were the same or slightly smaller than those of the MSA. However, due to shape factor, some materials tested larger by Microtrac (SPA) than by MSA. Microtrac (SPA) anlaysis time is approximately six minutes for duplicate results once the sample is introduced for testing. This contrasts with MSA analysis times of 45 minutes to over 3 hours for superfine material. Good results were obtained for median particle sizes of seven micrometers down into the sub-micrometer region. Considering that MSA particle size equipment is no longer manufactured by Mine Safety Appliances Company, the Microtrac (SPA) provides a good alternative for testing in the superfine range and has the added advantages of very rapid analysis time; simple operation; automatic accumulatiuon, calculation and printing of data and less operator time.

An evaluation was made of the Microtrac (SPA) to determine whether it would meet Atlantic Research Corporation needs for rapid analysis of superfine materials. In this size range, the Microtrac (SPA) proved to be as reproduciable as the MSA particle size analyzer. In most cases, particle size results of the Microtrac (SPA) were the same or slightly smaller than those of the MSA. However, due to shape factor, some materials tested larger by Microtrac (SPA) than by MSA. Microtrac (SPA) anlaysis time is approximately six minutes for duplicate results once the sample is introduced for testing. This contrasts with MSA analysis times of 45 minutes to over 3 hours for superfine material. Good results were obtained for median particle sizes of seven micrometers down into the sub-micrometer region. Considering that MSA particle size equipment is no longer manufactured by Mine Safety Appliances Company, the Microtrac (SPA) provides a good alternative for testing in the superfine range and has the added advantages of very rapid analysis time; simple operation; automatic accumulatiuon, calculation and printing of data and less operator time.

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Water Resources Section Name: Hydrometry (WRD 1) Designator of Legally Binding Document: IS 6339 Title of Legally Binding Document: Methods of analysis of concentration, particle size distribution and specific gravity of sediment in streams and canals Number of Amendments: Equivalence: ISO 4365 Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda