bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Paint Filter Test Method to Determine Free Liquid in Waste Samples
Authors: Rinaldo-Lee MB 
Published: December 2008

This paper presents the results from a round-robin testing program to evaluate the paint filter test method developed by the U.S. Environmental Protection Agency (EPA) to determine whether a waste contains “free” liquid. Regulations prohibiting disposal of waste containing “free” liquids in landfills were the impetus for developing the test method. Six laboratories performed the paint filter test on four waste samples to determine (1) whether the waste contained “free” liquid and (2) the percent “free” liquid released by the waste. The four waste samples were from two wastes; one waste was mixed with three different amounts of water to provide three waste samples.
The results show a large variance between the laboratories. The large variance is attributed mainly to sample preparation. The participating laboratories noted two other major problems with the test: (1) separation of the mesh from the cardboard filter holder during testing and (2) differences in filter design, which could influence test results.
Automated Pulsed Testing Using a Scatter-Probe Damage Monitor
Authors: Franck JB , Seitel SC , Hodgkin VA , Faith WN , Porteus JO 
Published: December 2008

This paper describes automated pulsed testing of infrared mirrors based on scatter-probe detection of laser damage. Advantages of our approach are (1) ability to monitor minute changes in surface condition without an observer, (2) rapid sampling of a large matrix of test fluences and test positions on the mirror, (3) automatic selection of test fluences, (4) automatic control of laser intensity drift, and (5) compatibility with a vacuum test environment.
Automated determination of damage frequencies and relative damage onsets will be described for single-layer-coated and uncoated metal and semiconductor mirrors. Tests were performed at 2.7 and 10.6 μm with 1/e2 focal spot diameters of 150 and 240 μm, respectively, using a nominal 100-ns pulse length in all cases. Results obtained with the scatter probe will be compared with those obtained from Nomarski postdamage analysis.
High-Precision Damage-Resistant Multiple-Pass Ultraviolet Reflectometer
Authors: Jolin LJ , Foltyn SR 
Published: December 2008

A multiple-pass cell was reported by John White in 1942 [1]. Since then, it has been adapted for use as a high-precision reflectometer. The multiple-pass reflectometer has been studied and reported by Arnon and Baumeister [2].
Here, a reflectometer which is similar is described. It utilizes a uv laser operating at λ = 351 nm as the source and the White-cell mirrors are high-reflection dielectric coatings designed for that wavelength. Because of the low-loss reflectors used in the cell, a high number of traversals, reflections, can be achieved; R ≥ 239. The use of dielectric mirrors also improves the damage resistance of the apparatus which is important when a uv laser beam is used.
The results of reflectance measurements performed on several ultraviolet high reflectors are also reported. These include conventional dielectric coatings as well as a hybrid coating consisting of Al2O3, HfO2, and SiO2 layers.
Surface Damage Mechanisms in Nontransparent Media
Authors: Fauchet PM , Siegman AE 
Published: December 2008

We review our experimental and theoretical work on surface transformations produced on amorphous and crystalline semiconductors and metals by single or multiple ultrashort laser pulses. In addition to melting and vaporization, two phenomena have attracted our attention: the formation of surface ripples and transformations due to repetitive subthreshold illumination.
A detailed theoretical model that explains successfully the formation and the major properties of the surface ripples has been developed and we illustrate the agreement by many examples. However, we also present experimental results which suggest that to describe the interaction between the incident beam and the surface diffracted waves, a perturbative approach is not always sufficient. A phenomenological explanation is presented for these nonstandard ripples.
Repetitive subthreshold illumination can produce the same surface transformations as single pulse illumination above threshold. We present universal growth curves and determine a safe level for multiple shot exposure in various materials. Our results are compared to several models, including accumulation of plastic deformation, creation of microcrystallites, and the early stages of ripple formation.
Picosecond-Pulse Damage Studies of Diffraction Gratings
Authors: Gill DH , Newnam BE 
Published: December 2008

Diffraction gratings are frequently used in dye-laser cavities as wavelength-tuning elements. These gratings often limit the maximum laser output energy because of their low damage thresholds. We have measured the damage characteristics of both ruled and holographically produced gratings, under a variety of conditions. Using the single-shot-persite mode, the samples were irradiated by 30-ps, 1.064-μm pulses having a spot size of 0.5-mm radius.
It was found that holographic gratings have damage thresholds from 1.5 to 5.0 times higher than similar ruled gratings. Thresholds for S-polarized light (E parallel to grooves) were higher by factors of 1.5 to 6. For the same type grating, gold coatings yielded higher thresholds than aluminum, although this is wavelength dependent. For holographic gratings, replicas have slightly higher thresholds than masters. Dependence upon groove spacing was weak.
Data are presented to show a variety of comparisons between different types of gratings, including two different manufacturers and usage at higher orders of incidence.
Assessment of Optical Coatings Prepared by Molecular Beam Techniques
Authors: Lewis KL , Savage JA , Cullis AG , Chew NG , Charlwood L , Craig DW 
Published: December 2008

Thin films of ZnSe and other materials have been produced by molecular beam techniques in an ultra-high vacuum facility dedicated to the examination of fundamental aspects of thin film technology as applied to optical coatings. The ZnSe films have negligible values of absorptance at 10.6 μm and have laser damage thresholds in the range 35–38J/cm2, a significantly higher energy density than hitherto reported for ZnSe films. Examination of the films in cross section by high resolution transmission electron microscopy has revealed a polycrystalline columnar morphology, with the crystallite size dependent on deposition temperature. A complete absence of intergranular voids is noted which renders the film impervious to the ingress of water and other impurities when exposed to the atmosphere. This feature, together with the inherently high purity of the film is believed to be the factor responsible for the enhancement in laser damage threshold.The electron micrographs do however reveal sub-grain structure in the form of stacking faults and twin planes which are potential sinks for residual impurities in the material. Further improvements in damage threshold may be possible by elimination of this sub-grain structure.
Effect of Anisotropic Stress on Thin Flim Damage Thresholds
Authors: Heiney AJ , Eastman J , Gabel CW 
Published: December 2008

Damage thresholds for silica/titania multilayer reflectors are measured using single, 30 ps, Nd:YAG laser pulses to study the effect of anisotropic stress on thin film performance. Damage testing sites near the edges of coatings were used to spatially correlate damage with reproducible anisotropic stress profiles taken parallel to the edge.
Anisotropic stress in a coating is stress which has a directional dependence in the plane of the film. A microscope based modulated ellipsometer is used to measure anisotropic stress via induced birefringence. The damage testing system centers around a vertical illumination microscope. The damage pulse is directed by a 45° high reflector in the microscope tube section through a low power objective. The sample surface is viewed through the same objective used to focus the laser to 8 μm FWHM in the center of the viewing field. The goal is to spatially relate this data with microscopic stress measurements.
In most cases, negative anisotropic stress areas are found to have lower damage thresholds while positive anisotropic stress correlates well with high damage threshold. Damage thresholds for uniform striplike areas of film are found to change dramatically compared to adjacent strips. In one case average damage threshold changed from 1.3 to 6.9 J/cm2 within 100 μm. The width of measured threshold bands in this work ranged from 0.5 to 2.5 J/cm2.
Survey of Laser Damage Thresholds for High Reflector Films at 1.315 Microns
Authors: Deaton TF 
Published: December 2008

We present the results of a survey of laser-induced damage measurements for high-reflector films at 1.315 microns. A pulsed atomic iodine laser with a maximum output energy of 5 Joules in a pulsewidth of approximately 8 microseconds was used, with a spot diameter at the sample of about 2.8 mm. All the thresholds reported are for single shot per site illumination. The pulse energy, temporal profile, and spatial profile information were monitored for each shot.The samples tested are part of an extensive survey of currently available coatings from several vendors and represent a wide variety of materials and designs. Each coating was prepared on both silicon and molydbenum substrates. Damage thresholds were defined by the presence of surface pitting visible under Nomarski microscopy. Threshold fluence levels ranged from 10 J/cm2 to 150 J/cm2 with uncertainties of typically ± 15%.
Effect of Load Transfer on Fatigue of Mechanically Fastened Metallic Joints
Authors: Lee EU 
Published: December 2008

Mechanically fastened joints are highly susceptible to fatigue cracking especially when varying loads are applied. The fatigue cracking is influenced by load transfer through fasteners.
Tests were conducted using zero, low, medium, and high load transfer specimens of 7475-T7351 aluminum. The fatigue crack initiation and growth and the final fracture behaviors were investigated. The fatigue crack initiation life, Ni, and the total fatigue life, Nf, are reduced by increasing stress range, Δσ, and load transfer level, L. The relationship is defined by the equations of the form logN=C−BΔσ−DLH where C, B, D, and H are constants. The fatigue crack growth rate, da/dN, is related to the stress intensity factor range, ΔK, by the equation da∕dN=(2.36×10−7)·(ΔK)2.89mm×cycle The crack initiation portion of the total fatigue life, Ni/Nf, is greater with lower stress range, Δσ, and longer total fatigue life, , is greater with lower stress range, Δσ, and longer total fatigue life, Nf, and it is reduced by load transfer.
A Demonstration of Aluminum Transport Deposition
Authors: LK Beard , JJ Conville , JC Wilson 
Published: December 2008

The Ford procedure, “Engine Test for Coolants in Aluminum Systems,” was used to demonstrate aluminum transport deposition in a Ford Escort engine with a silicate-containing coolant. Evidence of aluminum transport was gathered from physical and chemical analysis of coolant samples, corrosion specimen weight losses, and inspection of cooling system components. The loss of hot surface aluminum protection corresponded with the depletion of silicate from solution during the test. Corrosion of heat-rejecting aluminum surfaces led to the presence of aluminum in solution, and the resultant deposition of aluminum phosphate in the radiator. Inspection of the coolant passages of the aluminum cylinder head at the completion of the test showed evidence of extensive corrosion.
In a second dynamometer test, it was shown that aluminum transport deposition can be prevented by the use of a coolant with adequate silicate stability. In this case, the silicate concentration remained high enough to insure hot surface aluminum protection throughout the test. Evaluation of the radiator at the completion of the test showed essentially no loss of heat rejection capacity. Inspection of the cylinder head showed no signs of corrosion.
Propylene Glycol, A New Base Fluid for Automotive Coolants
Authors: FE Mark , W Jetten 
Published: December 2008

Propylene glycol is, because of its favorable toxicological properties, used as a base material for automotive engine coolant formulations in a number of European countries. In the present paper propylene glycol and ethylene glycol are compared with respect to relevant engine coolant properties like heat transfer characteristics, freezing protection, cavitation and erosion-corrosion, rubber compatibility, and toxicological properties. These properties are largely determined by the chemical and physical properties of the coolant base material rather than by the additive package which controls mainly corrosion inhibition.
Propylene glycol offers distinct advantages over ethylene glycol as a coolant base fluid as regards its toxicological and environmental properties and its cavitation resistance. With respect to the other properties both types of glycols behave very similarly.
Solder Bloom Corrosion Analysis Based on Field Survey Data, Potential Causes, and Resolution
Authors: Park KH 
Published: December 2008

A method to analyze field survey data on the solder bloom corrosion in copper/brass radiators is presented. In an effort to distinguish various manufacturers' radiator products according to their solder bloom corrosion performance, a corrosion index number is introduced (Park's Solder Bloom Corrosion Index). Using this technique, the solder bloom corrosion susceptibility of various manufacturers' radiators can be forceranked as a function of miles-in-service and months-in-service.
Potential causes for the solder bloom corrosion in the copper/brass radiators are analyzed from the standpoint of coolant type used, solder type used, different soldering processes, various internal rinse systems, and so forth. Based on the data analysis, a number of recommendations are presented for the potential resolution of solder bloom corrosion.
Stereological Characterization of Porous Microstructures
Authors: DeHoff RT 
Published: December 2008

The evolution of microstructure during powder consolidation consists of the disintegration of a connected network of porosity into separate parts, which ultimately disappear, and the integration of a grain boundary network from initially separated fragments into a connected network, which coarsens. The path by which these two processes develop depends upon the initial powder and its stack, the processing sequence, and the competition of various transport processes that produce microstructural changes. The properties of the material depend upon its final structure, which is the end point of the evolutionary path.
Stereology provides the means for characterizing the geometric properties of microstructures along the paths of evolution of the pore and grain boundary networks.
This paper reviews both the levels of description of the microstructural state and the principles involved in describing the evolution of the microstructural state during processing. These principles are illustrated with applications to evolving porous structures.
Sampling Effort Required to Find Rare Species of Freshwater Mussels
Authors: Kovalak WP , Dennis SD , Bates JM 
Published: December 2008

Several approaches for determining the sampling effort required to find rare species of freshwater mussels were examined. Methods based on the relationship between number of species and number of individuals collected may provide a basis for estimating sampling effort, but more research is required to verify their applicability. Collections of dead shells (from lake shores or river banks) cannot be used because dead shells do not accumulate in proportion to the occurrence of five specimens in adjacent waters. Methods based on quantitative sampling are most promising. However, several methodological problems must be overcome to make quantitative sampling cost-effective.
A tentative protocol for searching for rare species is presented. A preliminary survey using qualitative methods is used to determine the distribution of mussels in a habitat. These data are used to stratify the habitat for quantitative sampling, preferably using quadrats. The number of samples taken depends on the scope of the study. Sample number may be set by some predetermined target density that must be detected or by funding.
Characterizing the Influence of Natural Variables During Environmental Impact Analysis
Authors: Brown RT , Dycus DL 
Published: December 2008

Biological field sampling can be expensive, time consuming, and the results highly variable. A major goal of ecological data collection should be to obtain maximum information from each series of biological samples. Major factors regulating sampled populations must be identified if impacts are to be discriminated from effects of natural environmental variations.
There are often meteorological, hydrological, and water quality (physical-chemical) data available from nearby locations which can be used to describe the aquatic conditions between sample dates. This paper describes a methodology for using environmental data to better understand changes in biological populations by characterizing variations in natural factors.
Environmental factors which influence sampled organisms are examined to determine naturally occurring spatial gradients throughout the study region and temporal changes during the period of study. These environmental data are used to examine observed differences in sampled populations relative to natural environmental fluctuations. The methodology is demonstrated with environmental data used in the interpretation of phytoplankton samples. Recommendations are made for improving ecological data collection programs to allow analyses of impacts relative to natural environmental variations.
Compressibility and Settlement of Compacted Fills
Authors: Nwabuokei SO , Lovell CW 
Published: December 2008

Settlement predictions are necessary for compacted fills under a variety of circumstances (e.g., when fills are high, where major structural loads are to be supported, and when the fill materials are clays or weak rocks). As a result of an extensive testing program on both laboratory- and field-compacted materials, a systematic approach to this prediction has been developed. The recommended procedure involves one-dimensional compression testing in three parts.
The initial vertical strains experienced by the compacted fill are those due to self-weight. The magnitudes of these are highly dependent upon the values of prestress established by the compaction process; however, they occur as rapidly as the fill can be built. The major vertical strains will probably occur as the fill becomes wetter and “softens” in service. The timing of this settlement is uncertain, because it depends upon climatic variables at the site. Materials in the upper portion of the fill will often swell under the low confinement, and the net movement is an appropriate summing of these events with the compressions that occur deeper in the fill. Assuming that the fill becomes essentially saturated in service, further settlements can be produced by loading of the saturated material. The latter response is conventional in nature.
By testing a series of specimens, with a range of confinements which match those which will be imposed by the prototype fill, representative vertical strains are defined. Integration of these strains over the fill height produces the prediction of movement for the upper surface of the fill. The total testing and prediction technique is illustrated in the paper by example.
Influence of a Critical Gradient on the Consolidation of Clays
Authors: Dubin B , Moulin G 
Published: December 2008

Several studies in the laboratory have shown the existence of a permeability law which is different from Darcy's law and which defines the flow of the pore water in certain natural clays.
Consolidation tests in the laboratory, including the measurement of permeability at different stages of loading, that were carried out on Saint Herblain clay at the E.N.S.M. Soil Mechanics Laboratory prove the existence of major critical gradients (12 &lt; i0 &lt; 20). According to this observation, a consolidation model worked out with a non-Darcian permeability law has been produced by means of a finite-difference computer program.
On the one hand, this model is compared with Terzaghi's consolidation model and, on the other hand, the law that has been established is tested next to the laboratory tests.
Conventional Consolidation Tests on Two Soils
Authors: Chakrabarti S , Horvath RG 
Published: December 2008

The consolidation behavior of laboratory prepared “young” specimens of two clay soils, kaolin and Dundas soil, was examined using conventional consolidation tests. The specimens were prepared under either isotropic or K0 stress conditions. A fixed-ring type consolidometer was used for the tests. A 24-h loading time increment with a load increment ratio of 1.0 was used.
Test results indicate that the consolidation behavior of both soils was influenced by the past loading history and the test loading conditions. The soils were able to remember the past maximum stress.
Based on the test results, normalized e-σ‵v relationships are suggested for the two soils.
Centrifugal Evaluation of a Time-Dependent Numerical Model for Soft Clay Deformations
Authors: Mitchell JK , Liang RYK 
Published: December 2008

A series of centrifuge tests on embankment-type soil structures founded on soft clay is being conducted to evaluate a time-dependent constitutive model that incorporates the combined effects of creep and hydrodynamic consolidation. Because final coding of this new constitutive model has not yet been completed, a two-dimensional consolidation program (CON2D, developed by Chang and Duncan) is being used for preliminary analysis of test results. This paper describes the building, testing, and monitoring of the centrifuge models. The results of the centrifuge tests are interpreted and shown to compare well with predictions made using the CON2D computer program.
Centrifuge testing is a valuable method for investigating the accuracy and usefulness of new soil behavior models, particularly in the absence of or as a supplement to detailed field records. The testing limitations imposed by centrifugal environment—the radical acceleration field and “curved” stress distribution—are examined. Stress histories and stress paths experienced by the centrifuged model are shown accountable in the numerical analyses. Data generated in this testing program can provide a reference for evaluating other constitutive relations or numerical models, thus assisting further development of predictive analytical techniques.