bluuebunny/crossref_metadata_2025 huggingface dataset:
The Importance of Ohmic Potential Drop in Crevice Corrosion
Authors: Shaw BA
Published: March 2009

The IR drop along the length of a crevice plays an important role in crevice corrosion. Two examples of how crevice corrosion can be induced by IR drop are presented and discussed. The first example involves crevice corrosion of a passive film forming metal whose polarization characteristics do not need to be altered to establish crevice corrosion. The second example involves the crevice corrosion of a passive film forming metal whose anodic polarization characteristics do need to be altered to establish crevice corrosion and the alteration results from chemistry changes within the crevice. Polarization behavior in environments representing those found inside and outside the crevice will be used to illustrate the role of IR drop in crevice corrosion.
Predicting Stratigraphy at Landfill Sites Using Electromagnetics
Authors: Lawrence TA , Boutwell GP
Published: March 2009

Stratigraphic mapping has been done at several landfill sites using a statistical method of electromagnetic (EM) data interpretation which correlates the stratum depth with EM data at boreholes. The mathematical relationship developed by multivariate regression analysis is then used to predict stratigraphy at EM survey points. This method of Multivariate Regression-Prediction (MVRP) has been used successfully at a number of landfill sites for subsurface sand channel delineation, paleokarstic feature locations, and stratigraphic mapping between boreholes. MVRP results are in terms of depth or thickness, and do not require further data reduction.
Geotechnical Considerations When Planning Construction on a Landfill
Authors: Gifford GP , Landva AO , Hoffman VC
Published: March 2009

The closing of landfills has become commonplace. In many instances these closed facilities are desirable building sites because of close proximity to urban areas. Much of the subsurface investigation for foundation design parameters in landfills is more difficult and more expensive than for conventional sites underlain by soil or rock. A subsurface investigation of one particular landfill site is presented and discussed. The results obtained guide the decision making process for both further investigation and foundation type selection. The purpose of the paper is to inform the practicing engineer of one approach to the evaluation of geotechnical considerations of a landfill site.
Improvement of Mine Spoils in Southern Illinois
Authors: Koutsoftas DC , Kiefer ML
Published: March 2009

Field tests were conducted to evaluate the feasibility of preloading and dynamic consolidation to improve the compressibility characteristics of a mine waste spoil approximately 30 m deep. The mine spoils consisted of coarse granular materials ranging in size from sand to boulders for the lower 11 m and a heterogeneous mixture of materials ranging from clays to boulder size rock fragments for the upper 19 m.

A test fill approximately 7.6 m high was constructed in 10 days, and settlements were measured at various depths over a period of 200 days. Settlements as large as 45 cm were measured and most of the settlement occurred as soon as the test fill was completed.

Dynamic consolidation was performed in two test areas using different pounding grid configurations. The test areas were approximately 0.2 and 0.4 hectares, respectively. Dynamic consolidation was performed with a 16 ton pounder falling approximately 20 m. Geophysical tests as well as pressure meter tests indicate significant improvement of the spoils over depths of 9 m to 12 m.
Laboratory Testing of Lime Fixed Flyash and FGD Sludge
Authors: SOLIMAN NN
Published: March 2009

The operation of coal-fired power plants results in generating a considerable amount of flyash and flue gas desulfurization sludge. The properties of such material have not been widely reported and little is known about the field performance of this material when placed in landfills. This paper presents the results of extensive laboratory testing programs on six different mixes with variable flyash to sludge ratio. Lime was added as a fixing agent. Also, field samples from two operating power plants were tested in similar fashion, and results are presented and compared to laboratory testing results. In addition, a test pad was constructed from material produced by one of the operating power plants, and samples taken from the pad were tested.

Fixation of the flyash and FGD sludge by combining them with lime produces a mixture with improved properties over the flyash and the sludge. Generally there is significant improvement in structural characteristics, especially strength, and reduction in permeability by more than an order of magnitude. Therefore, the fixed material, with good quality control, could be handled and compacted easily in landfill.

Observation indicates that strength increases with time and with increase in density. The increase in strength when the mix was prepared utilizing brackish water is an important aspect observed during the study. Permeability results measured on samples prepared in the laboratory were found to be much lower than those obtained from field samples. Also, permeability was found to decrease with increasing density.
Constitutive Behavior of Clay and Pozzolan-Stabilized Hydrocarbon Refining Waste
Authors: Martin JP , Biehl FJ , Browning JS , Van Keuren EL
Published: March 2009

A project to stabilize acidic hydrocarbon sludge lagoons for landfill deposition is described. The sludge will be microencapsulated in a clay matrix, neutralized and cemented with a lime and fly ash pozzolanic mixture. The mechanical improvement and contaminant immobilization provide dimensional stability and low leachate production rates. Two types of clay were used as the aggregate in the stabilization mixture: a spent processing attapulgite and an onsite silty clay. Results of leaching, strength, and compression tests are presented for mixtures using each clay, as is preliminary analysis of the porous monolith response to in-situ stresses.
Landfill Deformation Monitoring and Stability Analysis
Authors: Duplancic N
Published: March 2009

An analysis of long term deformation monitoring data of a hazardous waste landfill is presented. A large number of field and laboratory tests provided an extensive data base for evaluation of the strength of the landfill materials. Slope stability analyses of the landfill's most critical section for static and seismic loading have shown that the landfill is stable.
Landfill Site Reclaimed for Commercial Use as Container Storage Facility
Authors: Hinkle RD
Published: March 2009

An abandoned 38 acre sanitary landfill approximately 100 feet (31 m) deep was closed, covered, sealed, and converted to a marine container storage and repair facility. An impermeable cover material was developed using crushed miscellaneous base, silt and asphalt emulsion. A large number of field and laboratory permeability tests were performed to verify the material properties. The landfill surface is used to support heavy container movers and two permanent structures. The project shows that landfill property can be reclaimed and put into profitable high demand use while meeting all environmental regulations.
Safety Recommendations in the Design of Athletic and Sports Fields
Authors: Mittelstaedt AH
Published: March 2009

The planning and designing of playing fields have become focal points of debate. The difference between natural and artificial turf is a part of this debate. However, in addition to the question of the surface material, a host of additional recommendations must be considered as they relate to safety, as well as the performance, operations, and other influences.

This paper addresses safety concerns related to ball fields used for baseball, softball, and junior baseball, as well as football, soccer, lacrosse, field hockey, and related field activities. For ball fields, factors affecting the infield, outfield, and sidelines are addressed, and for football and related fields, factors affecting the sidelines, field, and end zones are addressed, along with factors affecting the general area surrounding the fields. Such factors must become standardized and unified for field activities.
Matching the Playing Field to the Player
Authors: Adrian M , Xu D
Published: March 2009

This paper is a philosophical treatise on matching the artificial playing surface to the player. Questions are raised and answered regarding the field characteristics to be mea-sured and tested. The concept of force-time curves as an approach to better understanding of the requirements of playing fields is presented. Representative patterns often basic locomotor activities are described with respect to the forces against the surface. These patterns include walking, running, veering, cutting, stopping, dodging, pivoting, jumping, landing, and lunging. The absorption, traction, abrasiveness, and elasticity characteristics of playing fields are key elements related to the locomotor patterns used by the players of these sports. The problem is a complex one, but biomechanics researchers, materials engineers, and design engineers working together can facilitate the improvement of sports playing fields.
Recommendations for the Operation and Safer Use of Playing Fields
Authors: Cosgrove FA
Published: March 2009

Responsibility for the safe design, construction, management, and maintenance of athletic facilities clearly rests today with the owner/operators of these facilities.

Current litigation related to athletic injuries has shifted responsibility for the players “assumption of risk” to the operators “duty to provide a standard of care.”

This paper addresses three important legal implications—i.e., “reasonable manner, duty to care, and the standard of reasonable care”-by providing a number of specific guidelines directed toward the safe design, management, and maintenance of softball/athletic facilities. It also identifies guidelines designed to inform the players of the types of risks they will be exposed to and the appropriate steps they can take to reduce the potential for injury while they are participating in the softball program.

This paper represents the view of an owner/operator of a major softball program.
Traction Characteristics of Outsoles for Use on Artificial Playing Surfaces
Authors: Valiant GA
Published: March 2009

This report summarizes a series of studies which address the compromise between high translational and low rotational traction in the development of cleated shoe outsoles. In translation, a soccer shoe outsole must possess a coefficient of friction greater than 0.8 when forces are exerted in an anterior direction in order for the frictional forces to counter the high shear forces developed by a rapidly stopping foot. This can be achieved by molding outsoles from compounds such as styrene-butadiene rubber or by adding cleats as short as 2.6 mm to the outsole. If peak moments resisting rotation of a soccer shoe outsole could be reduced to values less than 30 N.m, the incidences of skeletal injuries may be reduced. It was also found that the classical laws of Coulomb friction do not apply to conventional soccer shoe outsoles. Coefficients of friction decrease with increases in normal pressure. This relation can possibly be exploited in future designs to reduce the compromise between translational and rotational traction.
Problems Associated with Testing the Impact Absorption Properties of Artificial Playing Surfaces
Authors: Martin RB
Published: March 2009

The problem of the safety of synthetic playing surfaces, as well as natural playing fields, is multifaceted. An important factor is the force generated when an athlete strikes the surface. Since this force is directly related to the total deformation of the surface-athlete system during the impact, the compressibility of the surface is a key factor to be considered in surface design and in testing of both new and old surfaces. Using a mathematical model, these concepts are developed in this study. The results show that the accelerations produced during an impact are greater for smaller masses, and equations are derived which indicate the appropriate scaling of the drop height needed to make impacts with small test masses that are equivalent to those of human body weights. The author suggests that testing of playing surfaces should not be limited to measurement of force impulses at a fixed impact momentum, which may be significantly less than the extremes encountered during use, but should include values revealing the total compressibility of the surface.
Prescription Athletic Turf System
Authors: Daniel WH
Published: March 2009

A root zone for natural grass of sports fields (planted surfaces) based on suction applied to a water control system has been developed and patented. Controlled water management by surface and/or subirrigation, conservation, and suction removal is automatically regulated by soil moisture sensing. The availability of sports fields for scheduled events regardless of weather is enhanced and wear tolerance increased. The Prescription Athletic Turf system is patented by Purdue Research Foundation as USA 3908385, 13 SE 75 and Canada 985516, 16 MR 76.
Performance Standards for Artificial Turf Surfaces
Authors: Breland RD
Published: March 2009

A set of test methods and some minimum standards have evolved which synthetic turf surfaces should meet or exceed, including proof by performance testing in the field before these materials and systems are offered in the marketplace.

Various technical properties and ASTM testing methods are described for use in compiling a complete, consistent artificial turf surface system. The minimum or limiting values for performance levels required, as well as typical or recently measured values for individual samples of synthetic playing surfaces systems and components, are described in this paper. The typical values are just that, and of course are subject to normal variations both in production control and in testing, especially when different testing laboratories are involved.

Laboratory testing conditions are controlled at between 20 and 22°C (68 and 72°F) and between 60 and 65% relative humidity, unless otherwise noted. These are essentially the standard textile laboratory test conditions specified in the ASTM Practice for Conditioning Textiles for Testing (D 1776-85), which calls for 65 ± 2% relative humidity and a temperature of 21 ± 1°C (70 ± 2°F). Testing in laboratories under markedly different conditions and techniques may give different test results in some cases.

The objective of this paper is to provide an overview of the test methods adopted for characterizing and documenting the performance properties of artificial turf, turf systems, and system components.
Selecting a Synthetic Turf Surface
Authors: Milner EM
Published: March 2009

The author discusses factors to be considered when selecting a synthetic turf surface. These include factors related to the playing of the game, as well as factors related to the cost, durability, and value of the synthetic surface.
The Role of Risk Assessment in the Regulation of Pesticides
Authors: Rachman NJ
Published: March 2009

Quantitative risk assessment is an important tool for regulating potentially carcinogenic chemicals including some pesticides. Although requiring that pesticide residue tolerances not exceed a specific dietary risk level may appear to be an effective risk management approach, it ignores significant limitations of calculated risk numbers that arise from uncertainties inherent in the risk assessment process. Determining what level of risk is to be considered negligible is a matter of policy rather than science. Different federal agencies and programs consider various levels of risk acceptable, but there appears to be some consensus that risks below 10-6 are negligible.
Development and Properties of

Transport

-- a New Inert Granular Carrier
Authors: Moechnig BW , Wilhelm BL
Published: March 2009

A new inert granular carrier has been developed by Cargill, Inc. for use in the formulation of granular insecticide/herbicide/fungicide/fertilizer products. The carrier is made by agglomerating finely divided organic material using a suitable binder, followed by drying and screening to the desired final moisture content and particle size. Physical property measurements show a bulk density in the range of 0.48-0.56 g/cc, water absorption of 29.9–47.5% and resistance to attrition of greater than 95%. Moisture content and particle size distribution can be varied by adjustments to the process. Comments from potential users indicate that this new carrier maintains its integrity during formulation, yet our results show that it disintegrates readily when placed in water. As a result, products formulated with this carrier have the potential for reduced avian toxicity by disintegrating when wetted, thereby preventing birds from ingesting intact granules.
Influence of Two Polymeric Adjuvants on Physical Properties, Droplet Spreading and Drying Rates, and Foliar Uptake and Translocation of Glypkosate in Vision® Formulation
Authors: Sundaram A
Published: March 2009

The effect of Sta-Put® and Silwet® L-7607 on physical properties (viscosity, surface tension and volatility), droplet spreading and drying rates, and foliar uptake and translocation of glyphosate was studied using white birch seedlings and branch tips. Three end-use mixtures were prepared using Vision®, one in water alone and the other two with 0.05% of the adjuvants in water. Physical properties were measured to examine their roles on droplet spreading and drying rates. Foliar uptake was investigated to study the effect of droplet spreading and drying rates on foliar retention; and translocation was studied to examine the role of the two polymers on bioavailability of glyphosate.

The adjuvants did not contribute to marked differences in the viscosities or volatilities of the three end-use mixtures, although the surface tensions were altered to some extent. Silwet caused a marked increase in the droplet spread areas, along with a simultaneous decrease in the droplet drying time. Staput did not alter any of these parameters. No simple relationship could be found between surface tensions of the mixtures and droplet spreading or drying rates. Both adjuvants contributed to an increase in the foliar uptake of glyphosate, but Silwet caused a much greater increase than Sta-Put, thus suggesting a relationship between droplet spreading and foliar uptake. Nevertheless, there was no significant difference in the amount of glyphosate translocated between the three end-use mixtures, thus indicating no evidence of reduced bioavailability because of the presence of the two polymers at the concentration levels used in the study.
Direct Injection of Dry Flow Able Agricultural Pesticides
Authors: Hart WE , Gaultney LD
Published: March 2009

A prototype system was designed to inject dry flowable formulations directly into the hydraulic conduit of a liquid spraying system. Representative samples of dry flowable pesticides were obtained to evaluate parameters which affect liquid dispersion and metering characteristics of each material. Laboratory tests were conducted to quantify the dispersion times of the formulations at labeled rates. Preliminary tests indicated that the dispersion times for packaged formulations were lengthy, but reduced with increased amounts of agitation. Reduction of formulation particle sizes was investigated to determine effects on dispersion times. Tests were performed to evaluate the accuracy and repeatability of the metering unit with different pesticide formulations. A laboratory test apparatus was assembled to evaluate the overall performance of the system on an agricultural sprayer. Tests involved the collection of pump effluent to determine the compatibility of the unit with field sprayers equipped with hydraulic nozzles which can accommodate dispersible granular formulations.
Droplet Dynamics in Hydraulic Nozzle Spray Clouds
Authors: Young BW
Published: March 2009

The spraying of a pesticide through a traditional hydraulic nozzle produces a heterogeneously sized droplet cloud. Three of the factors determining the fate of the droplets subsequent to their formation are: (1) the mechanics of the atomization process itself, (2) the forward motion of the nozzle and droplet cloud, and (3) any ambient wind. The Particle Measuring Systems Inc. (PMS) Imaging Spectrometer has been used to characterize the droplet cloud; and this data is related to the behaviour observed during motion, when twin inwardly curling vortices are formed behind the nozzle. These vortices become susceptible to drifting away from the target. An attempt has been made to characterize the vulnerability of a particular nozzle to produce a driftable component by assessing a factor termed the Drift Potential. Data are presented for a range of nozzles.
Droplet Spectra for Some Agricultural Fan Nozzles, with Respect to Drift and Biological Efficiency
Authors: Adams AJ , Chappie AC , Hall FR
Published: March 2009

The differences in drop size characteristics along the long axis of “fine”, “medium” and “coarse” sprays produced by agricultural fan nozzles were determined using the Aerometries Phase Doppler Particle Analyzer (PDPA). Water, water + 0.06% adjuvant, water + 0.4% emulsifiable concentrate (EC) and water +0.2% dispersible granule (DG) were sprayed through each nozzle. There was little difference in volume median diameter (Dv.5), number median diameter (Dn.5) or percent (by number and volume of the spray contained in drops <100um or >300um diameter when water was compared with the DG. However, the EC had a significantly larger Dv.5 than the water sprayed through five out of the six nozzles tested. Therefore, sprays produced by specific nozzles cannot be reliably defined on the basis of data for water alone. The percentage of spray volume contained in drops <100um diameter (most likely to drift) was 4 times greater in fine compared to coarse sprays. However, the 6-fold difference in flowrate results in the higher throughput nozzles producing most “driftable” volume per unit time. In coarse sprays, 69 — 84% by volume, but only 13 – 29% by number, was contained in drops >300um diameter (may rebound upon impaction). When these drops were artificially removed from the analysis, the Dv.5 was in the range 190 – 231um, irrespective of nozzle or'formulation. Thus, while coarse sprays contain, characteristically, large drops (which may contribute to off-target contamination because they are not retained well by plant surfaces), they are not associated with a reduced drift potential compared to fine sprays, based on volume production of drops <100um diameter.
Local Stresses in Metal Matrix Composites Subjected to Thermal and Mechanical Loading
Authors: Highsmith AL , Shin D , Naik RA
Published: March 2009

One of the important damage mechanisms in metal matrix composites is fiber/matrix separation. The interfacial region between the fiber and matrix is typically brittle and relatively weak, and therefore failure in this region may precede failure of the fiber and matrix. An elasticity solution has been used to analyze matrix stresses near the fiber/matrix interface in continuous fiber reinforced metal matrix composites. This micromechanics model consists of a cylindrical fiber and cylindrical sheath of matrix embedded in an orthotropic media representing the composite. The micromechanics model is used to predict thermal and mechanical properties for a lamina. These properties are then used in a laminate analysis to determine ply level stresses caused by a thermomechanical loading of the laminate. Finally, for a given ply, the ply level stresses and thermal loading are used in the micromechanics model in order to predict local stresses near the fiber/matrix interface.

Predictions from the closed form micromechanics model, which assumes cylindrical symmetry, have been compared to predictions from a finite-element model in which the fibers are arranged in a square array. Near the interface, stresses predicted by both models are in reasonable agreement. The micromechanics model was also used to predict the onset of fiber/matrix separation. Model predictions for a variety of laminates were in reasonable agreement with experimental data.
Plasticity Analysis of Fibrous Composite Laminates Under Thermomechanical Loads
Authors: Bahei-El-Din YA
Published: March 2009

Elastic-plastic behavior of fibrous composite laminates is analyzed for coupled in-plane mechanical loads and uniform thermal changes. Constitutive equations of the individual fibrous layers are derived from a vanishing fiber diameter model that represents the essential axial constraint between the phases. This permits derivation of closed form equations for the overall yield condition, stress concentration factors, and instantaneous compliance. Thermoelastic properties of the phases and yield stress of the matrix phase are functions of temperature. The effect of the model assumptions on the predicted behavior of composite laminates is examined by comparing the calculated response under cyclic thermal changes to available theoretical results and experimental measurements.
Computational Simulation of High-Temperature Metal Matrix Composites Cyclic Behavior
Authors: Chamis CC , Murthy PLN , Hopkins DA
Published: March 2009

A procedure was developed and is described that can be used to computationally simulate the cyclic behavior of high-temperature metal matrix composites (HTMMC) and its degradation effects on the structural response. This procedure consists of HTMMC mechanics coupled with a multifactor-mteraction constituent material relationship and with an incremental iterative nonlinear analysis. The procedure is implemented in a computer code that can be used to computationally simulate the thermomechanical behavior of HTMMC starting from the fabrication process and proceeding through thermomechanical cycling, accounting for the interface/interphase region. Results show that combined thermal/mechanical cycling, the interphase, and in situ matrix properties have significant effects on the structural integrity of HTMMC.
Effects of Environmental and Microstructural Variables on the Plastic Deformation of Metal Matrix Composites Under Changing Temperature Conditions
Authors: Daehn GS
Published: March 2009

A first order elastic-plastic model for the deformation of aligned, whisker-rein-forced metal matrix composites is developed. This model explains the experimentally observed weakening of these composites under thermal cycling conditions. This elastic plastic model and a more sophisticated power-law creep based model are used to demonstrate how deformation under stress and thermal cycling conditions will be affected by various environmental and microstructural variables. It is shown that the axial deformation rate is expected to increase with increasing amplitude and frequency of temperature cycles, and deformation rate should decrease with increasing matrix strength and whisker length. However, even continuous fiber reinforcement will allow for easy deformation if the composite is subjected to shear loading.
Analysis of a Ceramic Matrix Composite Flexure Specimen
Authors: Dharani LR
Published: March 2009

Three-point and four-point flexure tests are the commonly used strength and fracture toughness tests for brittle materials because of the simplicity of the technique and the ease with which the specimens can be fabricated. However, the formation of matrix cracks, single or multiple, on the tensile side of a ceramic matrix composite beam specimen destroys the macroscopic uniformity of the beam, and the use of the flexure formula for bending stress calculations results in large errors. In this study, an analytical model is developed to give a more accurate prediction of the behavior of a unidirectional ceramic matrix composite beam exhibiting multiple matrix cracking. A combination of stress intensity factor and micromechanics approaches is employed in determining the failure modes, the true compressive and tensile stresses in the composite, and the shear stresses at the crack tip. The functional parameters are the applied load, the beam geometry, and the microstructural properties of the onstituents The model predicts significantly different stresses than those obtained using the flexure formula.
Comparison of High-Temperature Tension Testing Results of Ceramic Fibers
Authors: Rigdon MA , Hong WS
Published: March 2009

Data on the tensile strength and modulus properties at high temperatures of three commercial ceramic reinforcement fibers were collected from several sources and compared. Differences in specimen geometries, test conditions, atmospheres, and procedures were noted and their probable effects on data variations considered. Suggestions for improving the uniformity of testing procedures and the acceptability of high-temperature mechanical test data for fibers are proposed.
Comparison of Methods for Determining Fiber/Matrix Interface Frictional Stresses in Ceramic Matrix Composites
Authors: Cranmer DC , Deshmukh UV , Coyle TW
Published: March 2009

In this study, several experimental methods including indentation push-in, in dentation push-out, and single-fiber pull-out tests were employed to measure the strength of the fiber/matrix bond in two continuous fiber reinforced ceramic matrix composites. The composite systems examined were a silicon carbide (SiC) monofilament reinforced borosilicate glass matrix and a SiC fiber tow reinforced glass-ceramic matrix Single-fiber pull out test results gave debond strengths (τd) of 11.1 ±3.2 MPa and interface frictional stresses (τf) of 3.6 ± 0.7 MPa for the SiC/borosihcate system. In the push out test, τd for the SiC/borosihcate system appears to be about 10 MPa while ts between 1 and 55 MPa were obtained in the SiC/glass-ceramic composite. The push-in test gave values of τf, between 2 and 34 MPa for the SiC/glass-ceramic system. Variability in τ within a specimen is due to differences in bonding between the fibers and matrix at various locations. The discrepancies in τ both within a test and between test methods are explained in terms of fiber/matrix bonding and test geometry. The most versatile test method appears to be the indentation push-out test.
Temperature-Dependent Tensile and Shear Response of P100/6061 Graphite-Aluminum
Authors: Fujita T , Pindera M-J , Herakovich CT
Published: March 2009

This paper summarizes the results of an investigation conducted to characterize tensile and shear response of P100/6061 graphite-aluminum composite in the temperature range -101 to 260°C (-150 to 500°F). The off-axis tension test and losipescu shear test methods were employed to meet this objective. The experimental results indicate that both the fiber dominated and matrix dominated elastic properties exhibit relatively small changes in the considered temperature range. The effect of temperature on yielding and strength however is significant under longitudinal and shear loading. Residual stresses play a significant role in controlling the variation of the yield stress with temperature. The observed low transverse strength of the composite is explained by interfacial defects between adjacent precursor wires induced during fabrication.
The Bonding Strength at the Fiber/Matrix Interface of Metal Matrix Composites
Authors: Kim J , Lee S-K , Jun E-J
Published: March 2009

A simple indentation method is used for measuring the interfacial bonding strength of a single continuous fiber reinforced metal matrix composite (MMC) to obtain its optimal manufacturing process in a vacuum-assisted squeeze casting. The effects of several manufacturing parameters on the interfacial bonding strength are investigated, including their interrelationships. By applying the optimal manufacturing process for the single fiber reinforced MMC to the bundled fiber reinforced MMC manufacturing process, it is shown that the measurement of bonding strength at the interface by a simple indentation method can be used to obtain the optimal manufacturing process of metal matrix composite in a vacuum-assisted squeeze casting
European Progress on Calibration and Standardization for Particle Sizing
Authors: Scarlett B , Merkus HG , Meesters GMH
Published: March 2009

This paper concerns the standardization and calibration of particle size measuring techniques. The theme of the paper is that the two activities are absolutely commensurate. Written standards must include recommended calibration procedures. The paper surveys the current status of activities in Europe which concern the production of standards and of calibrating materials. The particular problem of calibrating instruments to measure droplet size is discussed as well as the availability of techniques to produce fractions of monosized droplets. The intention of the paper is to contribute some small influence to the thinking of the currently active International Standards Organization (ISO) committees.
Morphology Dependent Resonance Measurements of Berglund-Liu Generator Droplet Dispersion
Authors: Bayvel LP , Driver HST , Knight JC , Robertson GN
Published: March 2009

This research exploits the well-documented morphology dependent resonances (MDRs), observed from lasing spherical droplets in the supermicron range, for highly accurate measurements of the size of droplets produced by the Berglund-Liu vibrating orifice mono-disperse aerosol generator. The measurement is several orders of magnitude more accurate than established methods.

Single dye-doped ethanol droplets, in the size range a = 15 to 45 μm, of known refractive index, from a nominally monodisperse distribution, were illuminated with the green frequency doubled beam of a single-longitudinal-mode neodymium: yttrium aluminum garnet (Nd: YAG) laser, and scattered light was collected at 90° to the incident beam. The collected light was dispersed and detected on an optical multichannel analyzer. The recorded spectrum is the broadband fluorescence spectrum, modulated by the regularly spaced MDRs, which act as wavelength-selective high-Q, cavities. At high values of the input intensity, the cavity provides positive feedback and amplification, characteristic of laser radiation. The smooth temporal profile associated with a single-longitudinal-mode laser improves signal-to-noise ratios above those achieved in previous work using a multimode pulsed laser. A good signal-to-noise ratio is vital if accurate information about droplet size is to be gained.

The study of the wavelength locations of the observed MDRs can provide highly accurate measurements of the droplet size and size variations. The accuracy of these measurements is limited only by imperfect knowledge of the refractive index, by asphericity of the illuminated droplet, and by experimental resolution and noise levels. Advantages over established methods include the high-speed, nonintrusive nature of the measurement and greatly improved measurement accuracy.
A Multiple Drop-Size Drop Generator for Calibration of a Phase-Doppler Particle Analyzer
Authors: Dressler JL , Kraemer GO
Published: March 2009

A multiple drop-size droplet generator was developed for Lycoming to calibrate spray measurement instruments with respect to drop diameter. The droplet generator can simultaneously produce one, two, or three drop diameters in the range of 50 to 450 μm. Drop diameters have temporal variations less than 1%, and each drop-size species is monodisperse to within 1%. Measurements of the spray produced by the multiple-size drop generator made with a properly aligned phase-Doppler particle analyzer, whose gain setting was optimized to reduce spurious validations about the largest diameter, gave accurate diameter readings within one or two measurement size classes or cohorts (2 to 4%). Transmitter lens spherical aberrations gave errors typically less than 3%.

Stimulated breakup of liquid jets, commonly called Rayleigh breakup, creates the droplets. Liquid, flowing from a pressurized manifold through orifices in a laminated nickel and copper plate, forms the jets. Piezoelectric transducers perturb the jets' velocity, breaking the jets into drops at the frequency of the velocity perturbations. Subharmonic velocity perturbations cause controlled agglomeration of the drops increasing the final droplet diameter and spacing. A stroboscope makes the droplets appear stationary for photographs and optical size measurement. Electrically charging the droplets creates a dispersion of controllable magnitude of the spray and a few reverse flow particles. Dividing the flow rate by the drop production frequency accurately determines the drop volume. The inexpensive and easily changed orifice plates contain 21 orifices spaced on a 2.54-cm line. Orifice diameters can be any size greater than 10 μm. In multiple diameter plates, the larger diameters are integer multiples of the smallest diameter.
The Method of Moments in Particle Sizing
Authors: Mroczka J
Published: March 2009

A connection between algebraic relations of angle scattering and integral parameters of particle-size distribution has been shown on the basis of the discussed measurement methods in which scattering at a small angle is fundamental. As shown, these relations allow for the determination of quantities characterizing the particle-size distribution without solving the ill-posed problems. Ordinary and center moments of the particle-size distribution function, f(a), are these quantities. They have a simple physical interpretation (for example, the number of particles, the sum of their diameters, the sum of cross sections, and of their volumes, in a volume unit). The center moments determine, for example, the distribution of an average particle diameter, the dispersion of function f(a), and so forth. A mathematical model of the way of moment function f(a) measurement and its practical realization are shown.
Small-Droplet Spray Measurements with a Scattered-Light Scanner
Authors: Ingebo RD , Buchele DR
Published: March 2009

The flow through pneumatic two-fluid nozzles was investigated to determine the effect of nitrogen gas mass-velocity on the Sauter mean diameter of water sprays produced by the breakup of small diameter liquid-jets in high-velocity gas streams. Tests were conducted primarily in the aerodynamic-stripping regime of liquid-jet atomization. It was found that the loss of droplets as a result of vaporization had a marked effect on drop-size measurements. A scattered-light scanner was used to measure Sauter mean diameters, with diameters as small as 5 μm, which were inversely proportional to the nitrogen gas mass-velocity raised to the 1.33 power. The exponent 1.33 is the same as that predicted by atomization theory for liquid-jet breakup in high-velocity gas streams.
A Laser Small-Angle Scattering Instrument for the Determination of Size and Concentration Distributions in Sprays
Authors: Hayashi S
Published: March 2009

This paper describes the development of a laser small-angle scattering instrument for size and concentration measurements of sprays at the National Aerospace Laboratory. A multiannular detector array having an optimal configuration for detecting diffractively scattered light signatures has been developed for the instrument. The inner radius of any detector element is exactly equal to the outer radius of the element placed in the immediate inside. Particle size distributions are determined from the measured energy data by nonlinear and linear best-fitting reconstruction methods. Application of the instrument to the diagnostics of a hollow cone spray is presented. The profile of the liquid concentration as well as the size distribution in the spray has been successfully determined by analyzing the line-of-sight integrated scattered energy data.
Optical and Electronic Limitations of the Forward-Scattering Spectrometer Probe
Authors: Baumgardner D , Cooper WA , Dye JE
Published: March 2009

An extensive evaluation of the optical and electronic measurement capabilities of the Particle Measurement Systems, Inc., forward-scattering spectrometer probe (FSSP) has led to a better characterization of this probe's measurement limitations. Measurements of droplet distributions are distorted as a result of mis-sizing and undercounting by the FSSP. These measurement errors have been traced to limitations imposed by the response time of the electronics, intensity inhomogeneities of the laser beam, and optical coincidence.

The optical and electronic characteristics of the FSSP have been mathematically modeled, and algorithms have been derived for the application of corrections that improve the accuracy of the measurements from these probes. These correction procedures adjust the measured concentrations for the effects of coincidence and deadtime losses and adjust the size distribution for undersizing caused by response time rolloff and laser beam inhomogeneities. This presentation summarizes the operational limitations of this instrument.
An Image-Processing Technique for Determining Focus and Statistical Information about Nonspherical Particles in Sprays
Authors: Zhang Y , Talley DG
Published: March 2009

An image-processing technique is presented for analyzing nonspherical particles in backlighted images of sprays. Focus discrimination is designed to accommodate not only the nonspherical shapes but also nonideal lighting conditions such as poor contrast and non-uniform shading. Additionally, in most cases the method is capable of recognizing when light transmitted or reflected through transparent particles makes them falsely appear as if they had holes in them. The algorithm is a postprocessor which can operate on stored digital image data either independently or in conjunction with other processing methods. Example applications are included.
Characterization of Aerial Spray Nozzles with Laser Light-Scattering and Imaging Probes and Flash Photography
Authors: Picot JJC , van Vliet MW , Payne NJ , Kristmanson DD
Published: March 2009

Laser light-scattering and imaging probes plus a flash photography system were used to count and measure droplets from a multiple-jet, nozzle-in-boom system with the jets facing downstream in an airflow. Tests were done in a laminar flow wind tunnel. The method of incorporating data from these different measuring systems is explained. The droplet diameter range measured was from 0.5 to 3600 μm. Tests cover air speeds ranging from 11 to 54 m/s, fluid flows from 1.8 to 8.8 L/min per nozzle, for 10-to 30-jet arrays per nozzle with jet inside diameters (ID) from 0.76 to 1.8 mm.

A correlation obtained for the volume median diameters from 14 tests shows good agreement with experimental data, for the single fluid studied: log10[Dv0.5/d0]=3.71-0.303log10-0.746log10We where d0 is the jet ID, Re is defined for the flow through a single nozzle, and We is based on d0 and the relative velocity of liquid to gas at the nozzle.
Sensitivity Assessment of a Phase-Doppler Interferometer to User-Controlled Settings
Authors: McDonell VG , Samuelsen S
Published: March 2009

Commercially available phase-Doppler interferometers have become highly flexible. As a result, a wide range of user-controlled parameters are offered. The present study focuses upon the influence that such parameters can have upon measured quantities. Specifically, photomultiplier tube (PMT) voltage and frequency shift are examined in this context. Two flows are considered: (1) a turbulent free jet to assess velocity measurement and (2) a spray produced by an air blast atomizer to assess size and volume flux measurements. The results from the jet indicate that, in low turbulence flows, the fluctuating velocity is slightly influenced by the amount of frequency shift and strongly affected by excess PMT voltages. In the spray, it is observed that PMT voltage strongly affects volume flux measurements and number mean diameter, but has little effect on Sauter mean diameter. Finally, it is found that frequency shift slightly reduces the detectability of particles and thereby reduces the volume flux, but has little effect upon the measured size.
Effect of Vaporization and Turbulence on Spray Drop-Size and Velocity Distributions
Authors: Reitz RD
Published: March 2009

Local drop-size, velocity, and liquid flux profiles were measured within conical steady sprays using a phase/Doppler velocimeter. The coflowing gas mean velocity, gridinduced turbulence intensity and length scale, and its temperature and pressure were each varied using a wind tunnel facility (gas velocity from 3 to 22.2 m/s, turbulence intensity from 2.7 to 8.6%, length scale from 8.4 to 17.8 mm, gas temperature from 300 to 750K, gas pressure from 101 to 610 kPa, and a differential injection pressure of 689 kPa). The results show that the turbulence in the gas influences the drop-size and velocity distributions. Drop mean and fluctuating velocity components were found to be close to the gas mean and turbulence velocities in regions where the drop-size-velocity correlation coefficient was low. The drop-size-velocity correlation decreased with increasing gas density and gas velocity. Drop-size distributions broadened, and the total amount of liquid vaporized increased when the turbulence intensity and scale were increased. At a given gas temperature, the amount of vaporization increased when the gas density was increased and the overall drop size (a flux-weighted Sauter mean over the spray cross-section) also decreased. However, local drop sizes were larger in vaporizing sprays than in nonvaporizing sprays at the same gas density. This interesting result could be due to the fact that the gas viscosity increases with increasing gas temperature and this increases the drop-drag coefficient, leading to reduced radial penetration of the spray. An additional factor is that, although vaporization reduces the size of all drops, smaller drops vaporize faster and drop-size averages are weighted towards larger drops.
Experimental Investigation of a Fan Spray Using Laser Diffraction and Phase-Doppler Instruments
Authors: Dannehl M , Schöne F , Schulte G
Published: March 2009

In the experimental work reported here, laser Doppler anemometry was used for “point” measurements of bivariate distributions of velocity and drop size (LDVS), and diffraction sizemetry (DSM) was used for line-of-sight measurements of drop size in sprays of water. Laser light sheet photographs were used to determine the spray geometry. The measurement positions were chosen so that the mean axes of the horizontal spray planes containing the LDVS measurement points coincided with the axis of the DSM laser beam. In this case, experimental results of DSM and LDVS are comparable, if one takes into account the laws of the conversion of drop flux (LDVS results) into a drop concentration (DSM results). Mean diameters as well as cumulative distributions obtained by LDVS at different measurement locations are compared with corresponding DSM results. Advantages and disadvantages of both methods with respect to spray analysis are discussed.
Overview: Technology Assessment in Medicine and Surgery and the Voluntary Consensus Standards Writing Process
Authors: Hedley-Whyte J
Published: March 2009

International standards activity in anesthesia and intensive care commenced in Technical Committee 121 on Anaesthetic and Respiratory Equipment of the International Organization for Standardization (ISO) in 1966 and was initially dependent on prior work by national standards writing bodies, especially those in the United Kingdom (British Standards Institution, or BSI), United States (American National Standards Institute, or ANSI) and France (Association Française de Normalisation, or AFNOR). National work has continued, but the United States committee was transferred to the American Society for Testing and Materials (ASTM) in 1983 [1].