bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Methods for the Quantitative Recovery of Bacteria Sorbed onto Marine Sediments
Authors: Scheraga M , Meskill M , Litchfield CD
Published: March 2009

Adsorption and desorption studies using both motile and nonmotile bacterial strains were performed with sedimentary sludge, clay, and sand in order to determine the most reproducible means for the recovery of viable bacteria from particles. The organisms used were Flavobacterium oceanosedimentum, Aeromonas proteolytica, and Escherichia coli, EPA 104. Viable cell numbers were determined using surface spread plate counts, direct counts via epifluorescence microscopy, and adenosine triphosphate analysis (ATP). Adsorption of the organisms onto sedimentary materials obtained from the New York Bight followed the Langmuir adsorption isotherm regardless of the length of time the cultures were in contact with the sediment. This implies that the initial events in the attachment of both nonmotile and motile bacteria to these types of sediment are primarily due to physical chemical forces. Desorption studies employed acidic, neutral, and basic surface-active agents; acid and basic pH treatments; osmotic shock; and peptone-water treatments. Physical manipulation of the sediment via shaking or agitation in the presence of 0.00001 percent cetyl trimethylammonium bromide appears to be the most effective and least toxic procedure for the recovery of viable microorganisms.
Techniques for Investigating the Role of Anaerobic Bacteria in Estuarine Sediments
Authors: Parkes RJ , Bryder MJ , Madden RH , Poole NJ
Published: March 2009

Techniques for investigating the anoxic sediments of shallow estuaries are described that are based on a simple coring technique that allows analysis without removal of the sediment from its core tube and minimizes oxygenation. Methods for the enumeration of anaerobic bacteria and for determining Eh, pH, pS2-, and the activity of sulfate-reducing bacteria are described in detail. The results from an investigation of a polluted estuary, using these methods, are presented in order to demonstrate the applicability of the proposed methods to investigations of anoxic sediments.
Three Experimental Regimes in the Study of Sediment Microbial Ecology
Authors: Christian RR , Wiebe WJ
Published: March 2009

To develop a predictive knowledge of the microbial ecology of sediments, an experimental approach must be taken. Examples of three experimental regimes in intertidal marine sediments are given. These regimes include in vitro mud slurry, in vitro intact core, and in situ experiments. Results varied qualitatively with the regime used. While in vitro regimes may be acceptable for testing certain hypotheses, they always represent models of the real system. Therefore, we advise the use of in situ experimentation whenever feasible.
Estimation of Microbial Activities in Lake Sediments by Measurement of Sediment Gas Evolution
Authors: Ward TE , Frea JI
Published: March 2009

The employment of an inverted sheet-metal cone permitted measurement of in situ evolution of methane and carbon dioxide from various Lake Erie sediments. The methane evolution rates varied from 0 to 71.5 mg/m2/h, while the carbon dioxide evolution rate reached a maximum of 6.1 mg/m2/h. The corresponding in vitro methane evolution or production rates demonstrated similar trends in some cases, but in other cases, obvious variations were observed. The in vitro variations in methanogenesis were attributed to the physical disruption of the sediment, which may have resulted in oxidation of the sample. The corresponding dissolved methane concentrations in the water column correlated well with the in situ methane evolution rates. In sediment regions where distinct lateral gradients of methanogenesis were observed, a corresponding gradient was observed in the overlying water column. Sediment regions consisting of clay, sand, or clay-sand mixtures showed no gaseous evolution. Minimal methane concentrations were observed in the water column above these sediments. The more active gaseous evolution occurred at near-shore regions, where external loadings contributed to the organic loading of the sediments.

The use of this inverted cone proved to be critical in assaying in situ methanogenesis. The in vitro methanogenic rates were susceptible to oxidation and resulted in variable estimations of net sediment methanogenesis. The association of this sediment methane and carbon dioxide evolution with sediment denitrification rates (nitrogen evolution) could provide valuable data for carbon and nitrogen budgets in freshwater systems.
Influence of Interstitial and Some Substitutional Alloying Elements
Authors: Plumtree A , Gullberg R
Published: March 2009

The toughness of several vacuum-melted Fe-25Cr and Fe-18Cr-2Mo ferritic stainless steels containing between 40 and 1000 ppm combined carbon and nitrogen has been investigated in the water-quenched condition. The toughness of these alloys has been assessed using notched-bar impact tests. For a given interstitial content, the ductile-to-brittle transition temperature and the impact shelf energy were not influenced by the presence of 2 percent molybdenum or the change in chromium content from 18 to 25 percent. In order to achieve a low transition temperature and high shelf energy, the combined carbon and nitrogen (C + N) content should be maintained below 150 ppm, in which case the interstitial amount has no effect. Exceeding this threshold level results in a marked increase in transition temperature and decrease in shelf energy. At higher interstitial levels [∼600 ppm (C + N)] further increases are not as significant. Addition of nickel resulted in a decrease in transition temperature, but this was accompanied by a decrease in shelf energy when compared with plain chromium steels with the same interstitial content. The addition of titanium, however, caused an improvement in both transition temperature and impact shelf energy.

It is shown that increasing the interstitial content of these ferritic stainless steels is associated with an increase in the amount of second phase present, particularly at the grain boundaries. Such particles enhance cleavage fracture by reducing the surface energy. The tendency toward a more brittle condition with increased interstitial content and larger grain size is explained in terms of the Cottrell theory for brittle fracture.
Application of High-Purity Ferritic Stainless Steel Plates to Welded Structures
Authors: Nakazawa T , Suzuki S , Sunami T , Sogō Y
Published: March 2009

This investigation deals with the practical application of high-purity 18Cr-2Mo-Nb ferritic stainless steel plates 6, 12, and 25 mm thick to welded structures.

In the V-notch Charpy test, the ductile-to-brittle transition temperature is about -30°C. The fracture toughness, Kc, determined by the deep-notch test is 350 kgf/mm2 · √mm for 12-mm-thick plate at -100°C. In the ESSO test, which has a temperature gradient, the Kc -value obtained is more than 400 kgf/mm2 · √mm at 0°C.

The toughness of the gas tungsten-arc welded joints using 316 L (C < 0.02 percent) wire deteriorated to some extent, compared with that of the base metal. In the deepnotch test (notch position: fusion boundary, heat-affected zone), however, the Kc-value is more than 200 kgy/mm2 · √mm at 0°C.

It is generally recognized that the safety of a weldable structural steel can be secured if its weld zone has resistance to brittle fracture initiation and the base metal has brittle fracture arresting properties. It can be concluded, therefore, that in thicknesses up to 12 mm this material can be used for welded structures at service temperature above 0°C because of its excellent fracture toughness.

Since the toughness of 18Cr-2Mo-Nb deteriorates with aging above 300°C or in cold-working in excess of 10 percent, and even further deteriorates in strain-aging, these effects must be taken into account in its fabrication.
Weld Heat-Affected Zone Properties in AISI 409 Ferritic Stainless Steel
Authors: Thomas CR , Apps RL
Published: March 2009

Although welding of thin-gage ferritic stainless steels is well documented, little information is available on the response of thicker (4.5 to 12.0 mm) sections to welding. With increasing interest in the use of heavier gages, it has become necessary to rectify this gap in knowledge. The work reported herein was undertaken to examine the metallurgical response of titanium-stabilized 11.5Cr steels to welding in terms of heat-affected zone (HAZ) structure, mechanical properties, and corrosion behavior.

Welds were made in four heats of steel to determine the thermal cycles occuring in the weld HAZ and to examine structures and give a general indication of joint properties. In order to examine the characteristics of different regions in the HAZ, a thermal simulation technique was used to produce specimens for examination and testing which had undergone a thermal cycle appropriate to a specific part of the HAZ. Parent steel, weldments, and simulated specimens were examined by optical microscopy, hardness testing, notch impact testing, and corrosion testing.

Four distinct regions of the HAZ were distinguished, as the HAZ was traversed from the unaffected parent steel to the fusion boundary. The amount of martensite formed reached a maximum where the HAZ peak temperature was in the duplex α + γ range. Impact transition temperature increased as the grain size increased, and martensite appeared to have little effect. In direct HAZ tests the transition temperature increased by 30 to 70 deg C irrespective of arc energy. Corrosion resistance deteriorated as the martensite content increased. Variations in nickel, manganese, and titanium within the steels used gave only minor variations in HAZ structure and properties, and it is concluded that compositional variations within the AISI 409 specification are unlikely to give significant improvements in the weldability of these steels.
Weldability of the New Generation of Ferritic Stainless Steels—Update
Authors: Krysiak KF
Published: March 2009

The 26Cr-1Mo alloys stabilized with titanium and the 29Cr-4Mo alloys have many potential applications in the chemical process industries. There is particular concern about the effect of interstitial content and the titanium addition on weldability, weld fracture toughness, and ductility.

This paper discusses the weldability of the new titanium-stabilized 26Cr-1Mo and 29Cr-4Mo (26-1 and 29-4) alloys in various commercially available thicknesses [3.276 to 3.81 mm] (0.129 to 0.150 in.), using matching and dissimilar filler metals, and compares the ductility and impact toughness of these materials with those of E-BRITE 26-1 (a high-purity ferritic stainless steel). Both the gas tungsten-arc and shielded metal-arc welding processes were used.

Welds were evaluated on the basis of tensile, bend, Charpy V-notch impact properties, and weld metal interstitial content (carbon, nitrogen, and oxygen).

Sound welds were made in titanium-stabilized 26Cr-1Mo and 29Cr-4Mo alloys. It was concluded that welding procedures that optimize gas shielding must be used. Routine gas tungsten-arc welding procedures are not adequate. Because of the high ductile-to-brittle transition temperature and low notch toughness observed in the gas tungsten-arc welds, this procedure is not recommended for fabrication of chemical process equipment from the stabilized ferritic stainless steels in the thicknesses studied. It was found that the welds made with high-purity filler metal were superior to those made with the titanium-stabilized filler metal.

The fracture behavior and notch toughness of the shielded metal-arc welds made with Hastelloy C-276, Hastelloy G, and Haynes 25 were satisfactory, and these procedures can be used for fabrication of chemical process equipment.
Toughness and Fabrication Response of Fecralloy Strip
Authors: Rosenberger GJ , Wright RN
Published: March 2009

Alloys of iron-chromium-aluminum-yttrium possess extraordinary oxidation and cyclic oxidation resistance and are attractive for automobile emission control hardware applications. They are, though, less tough than most ferritic stainless steels and care must be exercised in their general handling. Extensive practical use of light-gage strip is possible, however. This paper presents fundamental fracture mechanism observations on an Fe-15.9Cr-4.9Al-0.3Y alloy strip together with a detailed discussion of the fabrication of such Fecralloy strip en route to the manufacture of automobile emission control hardware. The implications for steel strip production practice are discussed and an assessment of light-gage strip fabrication latitude is presented.
Effect of Nitrogen on the Sensitization, Corrosion, and Mechanical Properties of 18Cr-8ni Stainless Steels
Authors: Eckenrod JJ , Kovach CW
Published: March 2009

Modern stainless steel melting and refining techniques now make it possible to consider nitrogen as an economic and controllable alloying addition to 18Cr-8Ni austenitic stainless steels. Studies show that nitrogen additions of up to about 0.16 percent to 18Cr-8Ni steels can result in some improved properties. Nitrogen is a strong strengthening element to 18Cr-8Ni steels and will increase yield strength by about 5.5 to 6.2 MPa (800 to 900 lb/in.2) for each 0.01 percent nitrogen. Isothermal time-temperature sensitization (TTS) diagrams developed for 18Cr-8Ni steels containing about 0.05 percent carbon and up to 0.25 percent nitrogen indicate that nitrogen at least up to 0.16 percent retards intergranular carbide precipitation. Corrosion tests on isothermally sensitized or welded specimens show reduced corrosion rates with nitrogen additions consistent with the TTS data. For low-carbon 18Cr-8Ni steels, nitrogen additions up to 0.15 percent have no apparent effect on the normally excellent sensitization resistance of these steels, at least as measured by corrosion tests on isothermally heated or welded specimens. Nitrogen additions were also found to improve pitting and crevice corrosion resistance as evaluated in anodic polarization or chloride pitting/crevice corrosion tests. Stress corrosion evaluations were conducted on solution-annealed material using constrained U-bend specimens in both severe and milder environments. The results indicated that nitrogen content up to 0.16 percent did not significantly affect stress corrosion cracking susceptibility, but 0.25 percent nitrogen appeared detrimental in some environments.
Influence of Small Amounts of Niobium on Mechanical and Corrosion Properties of Type 304 Stainless Steel
Authors: Sikka VK , Moorhead AJ , Brinkman CR
Published: March 2009

Creep and creep-rupture properties of several experimental heats of Type 304 stainless steel containing 20, 50, 100, 200, 500, 700, and 1000 ppm (by weight) of niobium were investigated in the temperature range of 482 to 649°C. Resistance to intergranular corrosion of these heats was also studied. Results of tests on the experimental heats were compared with the creep properties of 20 commercial heats of Type 304 stainless steel and data from the literature on several heats of Type 347 (4000 to 3000 ppm niobium) stainless steel.

Results on experimental heats were used to check that heat-to-heat variations in creep properties of 20 commercial heats of Type 304 stainless steel are caused by variations in carbon, nitrogen, grain size, and for the most part by residual niobium (10 to 200 ppm). The time to rupture increased and minimum creep rate decreased with increasing niobium content until a saturation level was attained at about 500 to 1000 ppm.

Type 304 stainless steel containing 500-ppm niobium offers superior creep and creep-rupture properties with improved creep ductility and a factor of approximately 5 better intergranular corrosion resistance [in boiling copper sulfate (CuSO4) solution] than Type 304 stainless steel (20-ppm niobium). In their welding work on the same heats, Moorhead et al have observed that Type 304 containing 500 to 1000 ppm niobium exhibits a weldability similar to that of Type 304 stainless steel.
Development of Austenitic Stainless Steels with Controlled Residual Nitrogen Content; Application to Nuclear Energy
Authors: Rabbe P , Heritier J
Published: March 2009

We have developed AISI 304 and 316 grade steels which exhibit, in addition to their good mechanical properties, intergranular corrosion resistance of the 304L and 316L grades. This development of what we shall call “optimized” steels has been made possible essentially by a detailed knowledge of the respective influences of carbon and nitrogen on the mechanical properties and intergranular corrosion resistance. The method by which such optimized steels are specified, as well as the comparison of their mechanical properties with the ASME Code data, is described. It is obvious that such grades are particularly useful for nuclear applications.
Improved Characterization of Sulfur Asphalt Materials for Structural Analysis
Authors: Cheetham A , Haas R , Kennepohl G , Bean D
Published: March 2009

A new testing apparatus for performing the indirect tension test has been developed. This apparatus has the capability of measuring both horizontal and vertical deformation during the test. Several sulfur-asphalt mixes of varying binder contents as well as two plastics of known properties were tested with the apparatus. Sets of curves were constructed to show the effects of variations of sulfur content on the resilient modulus, Poisson's ratio, and temperature susceptibility of the mixes.
Foamix Asphalt Advances
Authors: Ruckel PJ , Kole LL , Abel F , Zator RE , Button JW , Epps JA
Published: March 2009

Research studies and road applications utilizing the Foamix process during the past four years were reviewed by a five-member panel. During that period, usage of foamed asphalt has expanded from two to 16 countries worldwide. A small stream of water injected into hot asphalt cement results in a large-volume stream of foamed asphalt for easy mixing with cold wet aggregates. Conventional equipment is used for mixing and laydown. A wide range of aggregates, including, in particular, local marginal-quality materials, can be used.

Outside Australia and New Zealand, trial sections were constructed during 1977 in South Africa and Colorado, later in Botswana, France, and Germany, and most recently in Michigan. A full-depth, 9-km (5.6 mile) road was completed in North Dakota during the fall of 1979. Most use is for base sections ultimately given surface protection. One trial was an in situ application to recycled material. Foamixes have performed as unsealed liners for sewage lagoons and as stockpiled patch material.

Reviews of research studies in Colorado, California, and Texas provide a broad range of data from a variety of aggregates and test procedures. A counteragent has been developed to negate the effect of antifoam additives present in some asphalts.
Carbon Black Reinforcement of Asphalts in Paving Mixtures
Authors: Vallerga BA , Gridley PF
Published: March 2009

Dispersion of submicrometre-size carbon black particles in asphalt at dosages of 11 to 16 percent by weight of asphalt has been found to improve the asphalt properties of durability, wear resistance, and temperature-viscosity susceptibility. This concept of reinforcing asphalts with a carbon black filler has been made practical by pelletizing the carbon black with a high-durability maltenes binder compatible with asphalts. The pellets are packaged in 11.34-kg (25 lb) polyethylene bags which are introduced, bag and all, into hot-mix cycle of asphalt concrete batch-type plants. In continuous-type plants, the pellets are added either through the asphalt feedline in correct proportion to the hot asphalt or through the hot aggregate feed in correct proportion to the hot aggregate.

Since the carbon black becomes part of and bulks the asphalt, adjustments are made in batch weights to keep the volume relationship of binder to rock constant. Other design considerations are discussed.

Effects of the carbon black addition on the properties of asphalts and asphalt concrete, as measured in both laboratory and field experiments, are shown. The present status of a continuing program of field testing and evaluation is described.
Electron Spectroscopy in Catalyst Research
Authors: Brinen JS
Published: March 2009

Catalysis is an area of research which stands to benefit greatly from the development of surface analysis techniques. X-ray photoelectron spectroscopy (XPS), or electron spectroscopy for chemical analysis (ESCA), is one of these techniques and is already providing valuable information even though its limitations have not yet fully been established. This paper describes several applications of XPS to research in catalysis.

Two catalyst systems are discussed in terms of the type of information which can be derived by using XPS. The first one is the hydrodesulfurization (HDS) catalyst, which consists of oxides of cobalt and molybdenum on an alumina support. It will be shown how XPS studies can be used to elucidate the surface chemistry of activated HDS catalysts. The study demonstrates that both binding energy and intensity are required to describe the working catalyst fully. The HDS system is also used to demonstrate the use of XPS for quantitative surface analysis of catalysts.

The second catalyst system, rhodium on carbon, is first discussed in terms of catalyst deactivation. Changes in the intensity ratio of rhodium to carbon are used to monitor changes in the catalyst surface produced by hydrogen (H2) reduction at elevated temperatures and are related to catalyst performance. The results reinforce the importance of intensity ratios as a measure of catalyst dispersion. It is also shown, using rhodium on carbon catalysts with carbon supports, that observed intensity ratios are affected by properties of the support and therefore can result in significant errors in quantitative measurements.

Other aspects of the application of XPS to catalyst studies discussed are catalyst poisoning (auto exhaust catalyst) and the distribution of active components on catalyst surfaces (supported silver catalysts).
Ion Scattering Spectroscopy
Authors: Taglauer E , Heiland W
Published: March 2009

The backscattering of low-energy ions-typically He+ and Ne+, with primary energies between 200 and 2000 eV—has been applied to a variety of problems of the surface analysis of metals, semiconductors, and, also, insulators. The specific sensitivity of this method makes it particularly useful for composition and structure analysis of the topmost atomic layer. In this review the potential of the method will be demonstrated for three types of investigations in which low-energy ion scattering has been successfully applied.

In adsorption studies, ion scattering is used in addition to low-energy electron diffraction. The systems studied so far have contained, for example, oxygen, sulfur, and carbon monoxide as adsorbates and nickel, silver, and tungsten crystals as substrates. Ion scattering is used to obtain information about the position of the adsorbates and, in the case of molecules, about their orientation also.

Desorption of adsorbates by ion bombardment is widely used for target preparation in surface physics and also plays a decisive role in large vacuum vessels such as storage rings or fusion devices. Low-energy ion scattering is a very useful tool for systematic investigations of ion-induced desorption. The features of some of these studies will be shown, and data for desorption cross sections (including hydrogen) will be given.

In composite systems such as oxides and alloys, the properties of the topmost layer are of particular interest. Its composition depends strongly on the type of preparation, for example, sputtering or annealing (surface segregation). Low-energy ion scattering has been applied to analyze the composition of the outermost layer of a number of binary systems after different treatments. It is also particularly useful as a complement to other methods with different probing depths.

These examples will show the advantages and limitations of the technique and will lead to a short discussion of the present understanding of the underlying physics.
Application of a Vacuum Transfer Device for Exchange of Surface Standards
Authors: Hobson JP , Kornelsen EV
Published: March 2009

This paper first gives a brief technical summary of the properties of an ultrahigh-vacuum transfer device capable of transferring specimens between two ultrahigh-vacuum (uhv) systems anywhere on earth, maintaining the specimen at uhv at all times. The major objective of this paper is to explore the application of this transfer device for the exchange of surface standards. This includes the scientific objectives to be achieved and the practical problems involved. The authors conclude that transfers between most existing surface analysis instruments should be possible without overwhelming difficulties.
Digital Data Acquisition and Processing in an Auger Electron Spectrometer
Authors: Strausser YE
Published: March 2009

The historical development of data systems for Auger electron spectroscopy (AES) is reviewed with the purpose of putting the role of potential modulation differentiation in perspective. Typical current AES systems employ completely analog controls, signal trains, and data output devices. They use potential modulation differentiation with a lock-in amplifier measuring the first harmonic signal component as an approximation to the derivative of the secondary electron energy distribution. This approach to the generation of Auger spectra makes a considerable sacrifice in the signal-to-noise ratio and the quantitative accuracy in an attempt to improve signal “contrast” in the data. This sacrifice is not necessary when the E∙N(E) output, which is available from the cylindrical mirror analyzer (CMA), is used.

An AES system is described which uses a mini-computer, a microprocessor, a disk drive, and a graphics terminal to provide digital control functions, a digital signal train, digital data storage and processing, and reconversion to analog only in the final data display devices. This permits the acquisition of the E∙N(E) signal as measured by the CMA with no arbitrarily imposed modulation or system time-constant effects. This approach provides a high dynamic range in the data storage so that all data may be immediately stored in unprocessed form, which precludes the type of information loss that commonly results from incorrect sensitivity settings in analog systems. After the data are stored, a copy of the data may be digitally processed to provide the smoothing or averaging effect of a time constant, to differentiate the data, to integrate over specific peaks, etc. By converting the signal to digital form immediately after it leaves the CMA, the sensitivity to the pickup of stray noise is drastically reduced. The benefits of the digital approach are illustrated through examples from actual applications and through comparison with data from typical analog systems.
Control of Moisture Migration in Light Frame Walls
Authors: Wetterman TA
Published: March 2009

There is a serious need for better control of moisture in wall constructions. A number of currently used moisture control systems were evaluated under controlled laboratory conditions. Results indicated that systems of moisture barriers which were continuous by design or method of installation, or systems which allowed free passage to the exterior, were twice as effective in reducing moisture build-up within the walls as the other commonly used systems.
An Evaluation of Methods of Treating Rising Damp
Authors: Heiman JL
Published: March 2009

Rising damp problems frequently are encountered in old masonry buildings where either there is no damp-proof course (DPC) or the DPC has broken down. Moisture in contact with the base of porous masonry walls moves upward by capillary action unless there is an effective barrier to prevent this movement. The moisture invariably contains soluble salts that are deposited near or at wall surfaces where evaporation takes place. Salt crystallization and the associated expansion can cause deterioration of the masonry and surface finishes. The dampness problem sometimes can be overcome by the insertion of a new DPC or by impregnation of the masonry with chemical solutions that form moisture barriers. Electro-osmosis, cementitious grouts, damp-proof mortars, and Knapen tubes also have been used to treat rising damp, but often do not provide an effective solution to dampness problems. Where damp walls are contaminated with salts, the treatment of rising damp alone may not prevent continued deterioration unless measures are taken to reduce the level of salt contamination.
Effects of Thermal Insulation Penetrating Electrical Boxes
Authors: Clifton JR , Beausoliel RW , Meese WJ
Published: March 2009

When residential walls are retrofitted with “foamed-in” urea-formaldehyde or“blown-in” cellulose thermal insulations, the insulation may enter electrical outlet and switch boxes. The effects of these thermal insulations on electrical components such as outlet and switch boxes were studied.

Electrical outlet and switch boxes were filled with thermal insulation, and exposed to 44, 75, or 96 percent relative humidities for periods of 1 to 12 months. The amounts and rates of corrosion which took place were determined by measuring weight loss, corrosion current, and by visual inspection. Effects of the insulations on the performances of the electrical components also were investigated.

Results of this study indicate that shock hazards may exist if metal wall plates are used with ungrounded systems when they are in contact with moist thermal insulation. Therefore, it is recommended that thermal insulations should be removed from outlet and switch boxes.
Remarks to the Tenth Annual Boulder Optical Materials for High Power Lasers Symposium
Authors: Winsor H
Published: March 2009

Let me add DARPA's and my voices to Martin Stickley's welcome to the tenth annual gathering of the Boulder Optical Materials for High Power Lasers Conference. On my meeting papers this has appeared variously as “Boulder Damage Symposium” and “Laser Seminar.” You'd think by the tenth time around we would have found a name for this meeting.
Symposium Welcome
Authors: Glass AJ
Published: March 2009

It is my annual hope that each year's Symposium will be the last. Not because I dislike the subject, or because I find Boulder inhospitable, but because I'd like to think that we can solve the problems of laser damage, and move on to new challenges.
A Comparison of Bulk and Surface Absorptions in NaCl and KCl between 9.2 and 10.8 µm
Authors: Vora H , Ohmer MC , Stoebe TG
Published: March 2009

Tunable CO2 laser calorimetry has been used to study the wavelength dependence of optical absorption at 16 different wavelengths between 9.2 and 10.85 µm in NaCl and KCl. Samples prepared on a small scale using the reactive atmosphere process (RAP) growth, as well as samples cut from large diameter ingots prepared commercially for high-power CO2 laser windows, have been investigated. A differentiation between the bulk and surface absorption has been made in several cases using long bar samples. The measured bulk absorption in the best RAP-grown NaCl crystal is intrinsic over the entire wavelength range from 9.2 to 10.85 µm, showing bulk absorption values near 9×10-4 cm-1 at 10.6 µm and 1.4×10-4 cm-1 at 9.2 µm. The best KCl shows bulk absorption values near 9×10-5 cm-1 at 10.6 µm and 4×10-5 cm-1 at 9.2 µm; these values are above the expected intrinsic limit due to residual absorption caused by the presence of at least two bulk impurities, possibly ClO3- and ClO2-.
Bulk Optical Properties of Fine Grained Forged Calcium Fluoride
Authors: Anderson RH , Skogman RA , Ready JF , Bennett JM
Published: March 2009

Single crystals of CaF2 having ⟨111⟩. ⟨100⟩. ⟨112⟩. and ⟨113⟩ orientations have been routinely isostatically foreed in a helium atmosphere at 750°C. The crvstals were deformed 60 percent to ensure a uniform grain size of less than 15µm. A fine cloudiness of “veiling” occurs when the forging is done below the recrvstallization temperature of about 800°C for CaF2. Nomarski micrographs show that voids are distributed within the bulk of the forgings. Polariscope photographs show internal stress. Total integrated forward scattering measurements have been made on the sample immersed in a cell containing index matching fluid to eliminate scattering from the sample surfaces. These measurements show variations cannot be definitely correlated with the positions of veils in the CaF2.
Liquids for High Repetition Rate Glass Laser Systems
Authors: Rinefierd JM , Jacobs SD , Brown DC , Abate JA , Lewis O , Appelbaum H
Published: March 2009

We present physical properties data for a number of liquids currently being used for cooling and/or index matching of components in high peak power, low repetition rate Nd: glass laser systems. Liquids examined include saturated water solutions of ZnCl2 and ZnBr2, TCP, benzene, DMSO, glycerol, ethylene glycol, FC-104, Dow-Corning 710, and Cargille 5040 and 5610. Thermal properties (conductivity, diffusivity), mechanical properties (viscosity, density), chemical properties (pH, materials compatibility), and optical properties (refractive index, Abbé value, nonlinear index, dn/dT, optical transparency) are tabulated and compared to projected liquid properties requirements for high repetition rate systems.
Multithreshold Evaluation of 100-nsec Pulsed Laser Damage to Coating Materials at 2.7- and 3.8-µm Wavelengths
Authors: Porteus JO , Donovan TM , Jernigan JL , Faith WN
Published: March 2009

In this time and wavelength regime optical coatings typically fail from thermal damage. Unlike catastrophic damage resulting from dielectric breakdown, one finds disparity among the thresholds for one or more of the following damage characteristics: delamination, cracking, flow, erosion, perforation, ion emission, and light emission. Comparison of the different thresholds provides useful information on how damage proceeds, and how the absorbed energy is distributed in the coating layer. Comparison of multithreshold damage data at the two different wavelengths permits evaluation of the importance of impurities which absorb preferentially at one of the wavelengths, such as water. Comparing thresholds at the two wavelengths after N/1 conditioning provides detection of preferentially absorbing impurities which are laser-desorbed. Complementary information may be obtained from laser calorimetry. The following materials, prepared as single-layer, antireflection coatings, were evaluated: NaF, SiOx, Al2O3, ZnS, As2S3, and Si. Samples of the first three were prepared in ultrahigh vacuum, in addition to the usual standard vacuum preparation. Thresholds are expressed in terms of the theoretical energy per unit area in the coating layer in order to permit a practical intercomparison of materials for multilayer coating design.
Improved PbF2 Coatings for the Infrared
Authors: Baumeister P , Arnold GP , Edwards DF
Published: March 2009

A technique is described for reproducibly depositing single layer PbF2 antireflection coatings for CdSe that have a damage threshold of about 50 MW/cm2 for 2.87 μm laser radiation. This is an 8-fold increase in damage resistance over coatings made by other methods. These same coatings applied to Ge have a damage threshold of about 22 MW/cm2. The coated Ge value is less probably due to the index mismatch between the PbF2 and the Ge.
Simple Expressions for Calculating the Effect of Volume or Interface Absorption in Thin Films on the Performance of High Reflectance or Antireflectance Multilayer Coatings
Authors: Bennett HE , Burge DK
Published: March 2009

Approximate closed-form expressions are developed for predicting the effect of volume and interface absorption in thin films on the performance of quarterwave multilayer coatings. For highly reflecting coatings on dielectric substrates the volume absorption expressions are equivalent to those obtained by Sparks using a perturbation approach. The results are extended to metal substrates by introducing the concept of a generalized substrate index. An approximate expression for scattering losses for high reflectance coatings is included. Multiple quarter-wave antireflectance coatings are also analyzed using admittance theory. A technique for experimentally separating and determining interface and volume absorption in single-layer films has recently been reported. The expressions developed in this paper make it possible to predict the performance of high reflectance and antireflectance multilayer stacks from these single-film measurements without recourse to a computer.
Electric Fields Near Coated Surfaces: Application to Damage Protection
Authors: Rosenstock HB
Published: March 2009

Damage to transparent materials from intense light pulses usually begins at the exit surface. This is usually explained by “constructive” interference between incident and reflected waves: The total electric field may exceed the threshold for damage only upon reflection from the exit surface. However, in case of a surface coated with a thin film, interference may either increase or decrease the total electric field. Details depend on the optical constants, thickness, and wavelengths. A film designed to provide protection against excessive electric fields at one wavelength may not do so at other wavelengths. Also, attempts to minimize the field in the material proper may entail novel problems in the film, in which the damage mechanism may be an absorptive one.
The Relative Role of Impact and Multiphoton Ionization Mechanisms in Laser Induced Damage of Transparent Dielectrics
Authors: Gorshkov BG , Epifanov AS , Manenkov AA
Published: March 2009

The results of a theoretical analysis of the electron avalanche process at high frequencies of the electromagnetic field are presented. The dependence of the avalanche rate on radiation intensity and of the critical field on frequency are obtained for nanosecond and picosecond pulse durations. The relative role of electron avalanche and multiphoton ionization in laser damage of transparent dielectrics is discussed and it is shown that it is strongly influenced by the pulse widths.
Theory of Laser Damage in Dielectric Solids
Authors: Brawer S , Smith WL
Published: March 2009

In this theory a new approach to the interaction of conduction band (CB) electrons with damaging radiation is considered. We assume band gaps greater than 4 ev and radiation frequencies greater than 1 ev. Two processes are required for damage. First, the incident radiation rapidly excites a few “primer” electrons from trap levels to the bottom of the CB. Next these primer electrons can either cause enough energy to be absorbed to cause damage without avalanche, or they can trigger an electron avalanche and subsequent damage. In either case a mechanism for the excited-state absorption process is required.
Nondestructive Rapid Identification of Metals and Alloys by Spot Test
Authors: Committee E07
Published: March 2009

Description

Ten chapters cover the field including low alloy steels, tool steels, nickelchrom alloys, aluminum, copper, magnesium and their alloys.
Elastic-Plastic Fracture
Authors: Landes JD , Begley JA , Clarke GA
Published: March 2009

Description

The first major collection of papers devoted solely to the topic of elastic-plastic fracture. The papers present multiple approaches to this topic.
Service Fatigue Loads Monitoring, Simulation, and Analysis
Authors: Abelkis PR , Potter JM
Published: March 2009

Description

The symposium on Service Fatigue Loads Monitoring, Simulation, and Analysis was presented in Atlanta, Ga., 14-15 Nov. 1977. The symposium was sponsored by the American Society for Testing and Materials, through its Committee E09 on Fatigue, in cooperation with American Society of Mechanical Engineers, Society of Automotive Engineers, and American Society of Civil Engineers. The symposium was organized by a committee consisting of: P. R. Abelkis, Douglas Aircraft Company, McDonnell Douglas Corp., and J. M. Potter, Air Force Flight Dynamics Laboratory, cochairmen; H. Jaeckel, Ford Motor Company, SAE representative; W. Milestone, University of Wisconsin, ASME representative; B. Hillbery, Purdue University, ASCE representative; and J. Ekvall, Lockheed-California Company; H. Fuchs, Stanford University; D. Bryan, Boeing Company, Wichita.
MiCon 78: Optimization of Processing, Properties, and Service Performance Through Microstructural Control
Authors: Abrams H , Maniar GN , Nail DA , Solomon HD
Published: March 2009

Description

The symposium on MiCon 78: Optimization of Processing, Properties, and Service Performance Through Microstructural Control was held in Houston, Texas, 3-5 April 1978. Sponsored by Committee E-4 on Metallography of the American Society for Testing and Materials, the symposium was also cosponsored by The Metallurgical Society of the American Institute of Mining, Metallurgical, and Petroleum Engineers, the International Metallographic Society, and the Houston Chapter of the American Society for Metals. Dr. Halle Abrams, Bethlehem Steel Corporation, G. N. Maniar, Carpenter Technology Corporation, D. A. Nail, Cameron Iron Works, and Dr. H. D. Solomon, General Electric Company are editors of this publication.
Vertebrate Pest Control and Management Materials
Authors: Beck JR
Published: March 2009

Description

The second symposium on Test Methods for Vertebrate Pest Control and Management Materials was held 10 March 1978 in Monterey, Calif. Committee E35 on Pesticides of the American Society for Testing and Materials sponsored the event. J. R. Beck, Biological Environmental Consultant Services, presided as chairman of the symposium and served as editor of this publication.
Part-Through Crack Fatigue Life Prediction
Authors: Chang JB
Published: March 2009

Description

A collection of theoretical and experimental investigations that will substantially assist fracture mechanics technology in application, especially part-through surface crack fatigue life predictions.
Avian and Mammalian Wildlife Toxicology
Authors: Kenaga EE
Published: March 2009

Description

Most of the papers in this publication were presented at a symposium held in New Orleans, Louisiana, 17 October 1978. The symposium was sponsored by the American Society for Testing and Materials' Committee E35 on Pesticides in cooperation with Subcommittee E35.21 on Safety to Man and Environment. E. E. Kenaga, The Dow Chemical Company, presided as symposium chairman and editor of this publication.
Nondestructive Evaluation and Flaw Criticality for Composite Materials
Authors: Pipes RB , Scott WR , Kulkarni SV , Stinchcomb WW
Published: March 2009

Description

These papers attempt to characterize the many types of flaws frequently encountered in composite materials and to show how these flaws influence the response of material. This publication presents the state-of-the-art of nondestructive inspection methodologies, assesses deficiencies; evaluates the analytical methods for the description of critical flaw geometries and growth phenomena; and develops a basic understanding of failure phenomena and established methods of fractography.
Acoustic Emission Monitoring of Pressurized Systems
Authors: Hartman WF , McElroy JW
Published: March 2009

Description

A publication that addresses the acoustic emission technique as a viable complimentary nondestructive testing method. The papers presented draw a correlation between the generation of acoustic emission and defect growth; develop methods to evaluate and rank the severity of the flaw growth; and include the evaluation that acoustic emission method may be lower in cost than other inspection methods.
Full-Scale Load Testing of Structures
Authors: Schriever WR
Published: March 2009

Description

A comprehensive guide for load tests on full-scale buildings. This guide complements existing standards for load tests of materials and structural elements. This volume is divided into 2 sections: Objectives, Scope and Techniques of Full-Scale Structural Load Tests; and Application and Interpretation of Results of Load Tests.
Aquatic Toxicology
Authors: Eaton JG , Parrish PR , Hendricks AC
Published: March 2009

Description

This volume represents essentially all the basic and applied aspects of aquatic toxicology. Addresses such subjects as: biological monitoring; toxicology methods development; bioconcentration; water quality management; effluent testing; physiology and behavior; and single toxicant effects.
Effect of Load Spectrum Variables on Fatigue Crack Initiation and Propagation
Authors: Bryan DF , Potter JM
Published: March 2009

Description

Documents the significance of load spectra variation on structural life as measured by crack initiation and crack growth and presents an excellent service spectrum fatigue technology. Experts cover a wide variety of subjects from various engineering fields, such as load spectra representative of aircraft structures, gas turbines, and windmill structures along with analytical and experimental fatigue and fracture results and the effects of spectrum editing, time dependent changes in material characteristics, compression loads and gust alleviation.
Analysis of Waters Associated with Alternative Fuel Production
Authors: Jackson LP , Wright CC
Published: March 2009

Description

Acquaints you with the nature of the waters and attendant analytical problems arising from the production of fossil fuels from natural resources and new technologies.
Sampling and Analysis of Toxic Organics in the Atmosphere
Authors: Verner SS
Published: March 2009

Description

A new work full of innovative technical approaches and evaluative methods concerning toxic organics.
Health Effects of Synthetic Silica Particulates
Authors: Dunnom DD
Published: March 2009

Description

Focused on health problems caused by synthetic silica dust, STP732 brings you up to date on the complete picture of our present understanding of the physiological effects of silica particulates. Topics range from Characterization of Silicon Dioxide Surfaces by Successive Determinations of the Solution Rate to Immunological Aspects of Silica.
Formability of Metallic Materials—2000 A.D.
Authors: Newby JR , Niemeier BA
Published: March 2009

Description

This publication provides the current state of the art in this important field. 18 chapters contain the latest technological information on the use and selection of materials, comparison between steel and aluminum, and extends the concepts and needs of forming metallic materials to the beginning of a new century.
Aquatic Toxicology and Hazard Assessment
Authors: Pearson JG , Foster RB , Bishop WE
Published: March 2009

Description

STP 766 presents a discussion of the science's lack of quantitative growth and innovation based on the experience of those dealing in the practical application of aquatic toxicology as decision tools in aquatic toxicology as decision tools in aquatic safety assessment. However the papers contained combat this challenge and express new and innovative techniques for screening chemicals, for measuring population and community effects of stress, and field validation of lab-derived data.
Atmospheric Corrosion of Metals
Authors: Dean SW , Rhea EC
Published: March 2009

Description

The compilation of papers provides a good cross section of the state of the art in atmospheric corrosion. Some of the topics addressed include the behavior of engineering materials, weathering steels, metals with metallic coatings, monitoring atmospheric exposure sites, and laboratory tests and their correlation with atmospheric corrosion.
Rolling Contact Fatigue Testing of Bearing Steels
Authors: Hoo JJC
Published: March 2009

Description

This volume is a collection of papers devoted entirely to the problems of rolling contact fatigue testing of bearing steels. It is a good reference for all engineers and metallurgists working with rolling bearings and bearing steels. The results obtained by past researchers and a review of the most up-to-date state of the art are contained.
Short Fiber Reinforced Composite Materials
Authors: Sanders BA
Published: March 2009

Description

This publication is one of the few compendiums of information available on short fiber composites for high-volume process applications. The papers in this volume cover a wide range of topics including new material developments, test method development, mechanical and viscoelastic engineering properties, fracture behavior, and environmental effects.