bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogenated Amorphous Silicon Films: Preparation, Characterization, Absorption, and Laser-Damage Resistance
Authors: Donovan TM , Ashley EJ , Franck JB , Porteus JO
Published: March 2009

Evaporated Si films in combination with oxide materials such as SiOx form promising multilayer mirror coatings for chemical laser applications. However, high infrared absorption and relatively low damage threshold of the Si films presently limit the effectiveness of these multilayer designs.

Lower absorption values and higher damage thresholds have been obtained with sputtered Si films; this improvement apparently results from better film morphology and lower contamination levels in the sputtered films. Other work has shown that hydrogenation of as-deposited Si films can effectively passivate large numbers of bonding-type defects, and this results in further marked reductions in the infrared absorption.

In this paper, we discuss the preparation and absorption optimization of hydrogenated Si films and the formation of SiO2, Si/SiO2, and SiH/SiO2 coatings by reactive sputtering. The morphology and composition of optimally prepared films will be described, and the results of absorption and chemical laser damage measurements are discussed.
The Use of Self-Focusing in the Prevention of Laser-Induced Damage
Authors: Soileau MJ , Williams WE , Van Stryland EW , Brown SF
Published: March 2009

Laser-induced breakdown in thin foils and gasses have been used to limit transmission at high laser powers in order to prevent damage to sensitive optical components in complex laser systems. In this paper we report results of using self-focusing in liquids to produce laser-induced breakdown and phase aberrations which in turn limit the transmitted power. Optical self-action in CS2 and other liquids was used to make a power limiting device with psec response time. This device has linear response near unity transmission for input power below PC, which is of the order of the critical power for self-focusing, and limits the transmitted power to a nearly constant value for input power greater than PC. The onset of nonlinear transmission was adjusted by mixing various liquids to adjust n2. Experimental results using linearly and circularly polarized, 40 psec (FWHM) pulses at 1.06 μm are presented.
Two-and Three-Photon Absorption in Semiconductors with Subsequent Absorption by Photogenerated Carriers
Authors: Van Stryland EW , Woodall MA , Williams WE , Soileau MJ
Published: March 2009

A careful examination of two-photon absorption in CdTe and three-photon absorption in CdS and ZnSe was made by studying the transmission of picosecond pulses at 1.06 μm and the photoacoustic signal generated in the sample by the absorption of light. We found that in order to separate the direct nonlinear absorption from the subsequent absorption by the photogenerated carriers, careful analysis of the data over a wide range of irradiance levels was necessary. The nonlinear absorption coefficients for these three materials were determined, as well as an overall excess carrier absorption cross section. In addition, for CdTe we used two different temporal pulsewidths to verify our analysis. The photoacoustic data had a 1 to 1 correspondence with the transmission data indicating that this more sensitive technique should be useful for measuring nonlinear absorption spectra in solids with a variety of less powerful lasers. In addition for samples such as BK7 glass, which showed no nonlinear transmission even when surface damage occurred, the photoacoustic signal showed abrupt large increases when damage occured. No nonlinear absorption was observed in two types of CVD ZnS prior to damage.
Material Resistance and Instability Beyond J-Controlled Crack Growth
Authors: Ernst HA
Published: March 2009

A modified version of the J-integral, JM, is introduced extending previous results of Rice, Drugan, and Sham. It is proven that JM always satisfies the Rice condition; that is, ˙JM must not depend on ˙a. The implications for instability are discussed in terms of the corresponding modified tearing moduli. Experimentally obtained data from compact specimens of a A508 Class 2A steel ranging from ½T to 10T were successfully correlated by using JM even well beyond the J-controlled crack growth regime. Also, the correlation of data from bending and tension specimens is shown to improve significantly when JM is used. Limitations for the use of the deformation theory J are set in terms of new parameters.
Cracks in Materials with Hyperbolic-Sine-Law Creep Behavior
Authors: Bassani JL
Published: March 2009

At high stress levels the creep strain rate for many materials varies as the exponential of stress while at low stress levels it varies as stress to some power. An analysis is presented for a stationary crack under antiplane shear or Mode III loading in a material that deforms both elastically and by hyperbolic-sine-law creep, ˙εc ∝ [sinh (σ/σ0)]n. The asymptotic crack-tip stress intensification is weaker and the strain-rate intensification is stronger than for a power-law creeping material. The elastic stress-intensity factor KIII (for low applied loads) and the path-independent integral C* are shown to be the relevant short-time (small-scale yielding) and long-time (extensive creep) loading parameters as in the power-law case.
Microstructural and Environmental Effects During Creep Crack Growth in a Superalloy
Authors: Floreen S
Published: March 2009

Two heats of a nickel-base superalloy were heat-treated to form three different grain boundary carbide microstructures, a blocky M23C6 carbide, a cellular M23C6 carbide, and a carbide-free structure. Creep crack growth rate tests were run at 650°C in four environments: high-purity helium, air, He-4CH4 and He-3SO2. Crack growth in all cases was intergranular and involved the nucleation and growth of micrometre-sized cavities on the grain boundaries. The air and He-3SO2 environments were very aggressive, increasing the crack growth rates over those in helium by more than 100-fold. The grain boundary microstructures significantly affected the growth rates, and microstructures that were best in some environments and were worse in others. The results suggest that a single, generalized cavity nucleation and growth mechanism may be responsible for crack growth in superalloys, but environment-microstructure interactions will have to be accounted for to provide a satisfactory description of the cracking behavior. The results also suggest that some of the general ideas about the role of carbides in superalloys may not be true under crack growth conditions, and that alloys optimized by tests in air may not be the most suitable for use in other environments.
Effects of Synthetic Silicas on Mouse Peritoneal Macrophages In Vitro
Authors: Davies R
Published: March 2009

The cytotoxicity of synthetic amorphous silica particulates on mouse peritoneal macrophages in vitro was examined in an attempt to assess their fibrogenic potential in vivo. Fumed silicas and micronised silica gels were found to be as cytotoxic as a standard crystalline silica (Dorentrup No. 12); a precipitated silica was less cytotoxic. These results suggest that synthetic amorphous silicas would be pathogenic in vivo (after inhalation or intraperitoneal administration). However, available animal studies on other similar silicas indicate that they are only pathogenic after prolonged exposure. It is suggested that more in vivo information regarding the fibrogenicity of amorphous silicas is required.
Chronic Effects of Inhaled Amorphous Silicas in Animals
Authors: Groth DH , Moorman WJ , Lynch DW , Stettler LE , Wagner WD , Hornung RW
Published: March 2009

Rats, guinea pigs, and monkeys were exposed by inhalation (5.5 to 6 h/day, 5 days/week) for up to 18 months at 15 mg/m3 concentrations of three types of synthetic amorphous silicas: fume, gel, and precipitated. Autopsies on rats were performed after 3, 6, and 12 months of exposure, and on guinea pigs and monkeys after 10 to 18 months of exposure. The most significant finding was the deposition of large quantities of amorphous silica in macrophages in the lungs and tracheal lymph nodes of exposed monkeys. Relatively few or no macrophages containing particles of amorphous silica were found in the lungs and lymph nodes of the guinea pigs and rats. It is also significant that fume silica induced early nodular fibrosis in the lungs of the monkeys. Correlating these histological findings, lung-function studies indicated statistically significant differences in lung volume and ventilatory mechanics measurements between those monkeys exposed to fume silica and the control group. In addition, monkeys exposed to precipitated silica demonstrated significantly lower lung volumes compared with controls, while monkeys exposed to silica gel had significant changes in ventilatory performance and mechanical properties.
Biological Action of Precipitation-Process Submicron Amorphous Silica (HI-SIL 233)
Authors: Schepers GWH
Published: March 2009

The siliceous material which is the subject of this study has been produced commercially in the United States for approximately 30 years. Since both production and use of the material may result in human inhalation exposure, it was necessary to explore the biological potentials of the silica by exposing experimental animals to aerosols of the material. Since crystalline silica is able to augment the severity of tuberculosis, an infection phase was included. Nine component experiments involving 496 animals were conducted over a period of three years. Average dust concentrations were 3.57 mg/ft3 of air. Rats, guinea pigs, and rabbits were exposed. The tuberculous infection studies were limited to the guinea pigs. An elimination phase was included for each animal species. Deaths among control animals and exposed animals were approximately the same and were due to intercurrent infections or other natural causes. Lung weights increased pari passu with dust exposure, but returned to normal ranges after exposure stopped. Silica retention in the lung tissue ran parallel to this, and silica was relatively rapidly eliminated on cessation of exposure, with commensurate reduction of the lung ash. A transient type of alveolar hyperinflation of mild to moderate severity occurred in rats more particularly, but this was more related to intercurrent infection than to the silica itself. Macrophages accumulated in alveoli, in the bronchioles, and in lymphoid tissue. This remained a mild reaction in rats, but was more evident in guinea pigs and rabbits. In guinea pigs there was more infiltration of lymphoid tissue by these macrophages and far less alveolar hyperinflation. In rabbits the macrophage accumulation tended to be perivascular whereas in guinea pigs this response was more peribronchial. Almost complete reversal of all these responses occurred. Some reticulum deposition was noted in interstitial tissues. This disappeared on cessation of exposure. Bronchial and tracheal epithelia remained intact. No epithelization or pleural changes were noted and no neoplasia occurred. The tuberculogenic response was limited to a slight increase in size of some lesions and slightly longer persistence of the active cellular proliferation phase of the tubercles before resolution and calcifications. No extrapulmonary spread of the tuberculosis occurred. On the basis of the foregoing and by comparison with twenty-four other varieties of silica previously studied in comparable fashion, the precipitated submicron amorphous silica is the least biologically active of the synthetic silicas. Thus on a percentile scale its biological action may be rated at about five percent of the capability of the most injurious siliceous materials.
Fracture Mechanics and Corrosion Fatigue
Authors: Wei RP , Shim G
Published: March 2009

The role of linear fracture mechanics is considered in relation to the importance of integrating chemistry, mechanics, and materials science in the development of a quantitative mechanistic understanding of corrosion fatigue. The value of and need for an integrated multidisciplinary approach are illustrated by results of studies of environmentally assisted fatigue crack growth in gaseous and aqueous environments. Corrosion fatigue of steels in aqueous environments is considered to provide new perspectives for this integrated approach. The need for treating cyclic load frequency as an important variable and for electrochemical measurements at short times (<10 s) is discussed.
Experimental Observations of Environmental Contributions to Fatigue Crack Growth
Authors: Bowles Quinton C , Schijve J
Published: March 2009

Aluminum 2024-T3 and 7075-T6 center-cracked panels were fatigued in a dry air environment of 10 ppm water vapor. Blocks of 100 cycles having 1, 3, or 5 cycles at 0.02 Hz and the remainder at 20 Hz were employed. Fractographic observations at crack lengths between a = 4 mm and a = 12 mm revealed striation formation corresponding to the slow cycles followed by a transient region containing approximately 15 additional striations formed at 20 Hz. These striation bands were then separated by a flat featureless region. For crack lengths less than a = 4 mm extensive striation formation was found, while for crack lengths greater than a = 12 mm only striations corresponding to slow cycles were found.

An analysis of the experimental results supports a mechanism of adsorption of water vapor, disassociation to produce free hydrogen, and subsequent surface migration of hydrogen to the crack tip. It is felt that diffusion of hydrogen into the plastic zone ahead of the crack tip does not adequately explain the environmental effect as represented by the presence of striations. A more plausible explanation appears to be the lowering of δcritical required for bond rupture of atoms at the crack-tip surface.
Corrosion-Fatigue Behavior of Ti-6Al-4V in a Sodium Chloride Aqueous Solution
Authors: Ebara R , Yamada Y , Goto A
Published: March 2009

To clarify the influence of NaCl aqueous solution on corrosion-fatigue crack initiation of mill-annealed Ti-6Al-4V, rotating-bending fatigue tests of notched specimens with stress concentration factors in the range of 1.5 to 3.5 were conducted in aerated and deaerated 3% NaCl aqueous solutions at 80°C. Ultrasonic fatigue tests up to 1010 cycles were also conducted in aerated 3% NaCl aqueous solution at room temperature.

Fatigue limits in air and corrosion-fatigue strength at 108 cycles decreased with increases in the stress concentration factor. The reduction in fatigue strength of the notched specimen (Kt = 3.5) by the environments at 5 × 107 cycles was at most 20%. No influence of dissolved oxygen content was observed. Corrosion pits were not observed at crack initiation sites.

In the propagation area, striation predominantly appeared regardless of environment. It was concluded that corrosion-fatigue crack initiation of the notched Ti-6Al-4V was predominantly influenced by the stress concentration factor and not by Cl− ions or dissolved oxygen content in the NaCl aqueous solution. It was also concluded that fatigue crack initiation of Ti-6Al-4V was not significantly influenced by the NaCl aqueous solution at room temperature even in long fatigue life (up to 1010 cycles).
Some Electrochemical and Microstructural Aspects of Corrosion Fatigue
Authors: Congleton J , Craig IH , Olieh RA , Parkins RN
Published: March 2009

The initiation of corrosion-fatigue cracks in pure aluminum single crystals, polycrystalline aluminum, and in a BS4360 50D steel has been investigated. Experiments were performed in 3.5% sodium chloride solution, and measurements of the rate of nucleation and early growth of cracks were obtained by quantitative metallography. Initiation occurred at persistent slip bands or grain boundaries in aluminum but at inclusions in the steel.

The role of microstructure in corrosion fatigue crack initiation is discussed. It is suggested that the growth rate of short cracks may be controlled by chemical dissolution. Results from straining electrode experiments on high yield strength steels are described that support this conclusion.
Implementing Corrosion-Fatigue Crack Growth Rate Data for Engineering Applications
Authors: Bamford WH
Published: March 2009

Fatigue has often been described as the most common cause of failure in engineering structures, and designers have incorporated fatigue considerations for many years. As the state of the art has advanced, the capability has been developed for allowing for the presence of a crack by predicting its growth and calculating the size which could lead to failure. The crack growth testing and analysis procedures are now well developed, and there is little question as to which data are appropriate for use in such an analysis in a dry environment, for any material.

Prediction of the behavior of fatigue cracks in other environments requires many more considerations, and in fact a multidisciplinary approach is called for, involving chemistry, mechanics, and metallurgy. This paper will discuss some of the possible ways in which information from each of these disciplines can be synthesized into an engineering approach to corrosion-fatigue crack growth predictions. Such an approach would require more than simple data collection from tests, because the relationship of the test environment to the actual environment must be established and proper allowance made for any differences. Moreover, since all the environmental and loading conditions that exist in the application are not always possible to address in testing, some consideration of the mechanisms operating in the material and environment of concern is essential to a good engineering approach.
Fatigue Design Stresses for Weathering Steel Structures
Authors: Albrecht P
Published: March 2009

Unpainted steel structures exposed to atmospheric environments lose initiation life due to rust pitting and propagation life due to corrosion fatigue. The former loss is determined from an analysis of 1195 fatigue tests of six types of details that were weathered up to four years; the latter from corrosion-fatigue crack growth rates. Proposed equations predict the total loss in life or stress range for Category A to Category E details, as defined in all fatigue specifications for civil engineering structures. The losses are largest for Category A and diminish with increasing severity of the detail. The findings are applied to simple-span bridges.
Eddy-Current Characterization of Materials and Structures
Authors: Birnbaum G , Free G
Published: March 2009

Description

Authoritatively covers all areas of eddy-current nondestructive evaluation, including developments in theoretical models for specific eddy-current problems, analysis of available instrumentation, and microwave, multi frequency, and pulsed eddy-current methods.
Fatigue of Fibrous Composite Materials
Authors: Lauraitis KN
Published: March 2009

Description

An ASTM book on the understanding of fatigue mechanisms that cover a wide range of topics from theory and experimental studies to prediction models, test methods, and review of classic procedures.
Ecological Assessments of Effluent Impacts on Communities of Indigenous Aquatic Organisms
Authors: Bates JM , Weber CI
Published: March 2009

Description

Authoritative information ranges from environmental impact analysis of aquatic ecosystems using rational threshold value methodologies to annual macroinvertebrate sampling--a low cost tool for ecological assessment of effluent impact.
Physical Testing of Plastics—Correlation with End-Use Performance
Authors: Evans RE
Published: March 2009

Description

Discusses the physical tests necessary to obtain data relevant to an intended application. The text demonstrates clearly how one analyzes end-use requirements and correctly chooses tests and conditions.
Aquatic Toxicology and Hazard Assessment
Authors: Branson DR , Dickson KL
Published: March 2009

Description

The book covers discussions of new concepts, methods and research results in aquatic toxicology and hazard assessment. This book is broken down into three sections: safety margins; environmental chemistry and fate modeling; and application of aquatic hazard assessment principles.
Ferroalloys and Other Additives to Liquid Iron and Steel
Authors: Lampman JR , Peters AT
Published: March 2009

Description

This publication provides a review of less well-known aspects of ferroalloys and other additives. A special feature in this publication broadly lists the alloys and other additives used in the ferrous and nonferrous industries; the second lists densities and thermal effects of addition of a number of common ferroalloys.
Fracture Mechanics
Authors: Roberts R
Published: March 2009

Description

Fracture mechanics has become one of the preeminent disciplines utilized in the evaluation of structural integrity during the past 20 years. This publication covers the following topics: fatigue of engineering materials with principle applications to metals, stress-intensity factors; elastic-plastic fracture mechanics, and fracture mechanics and structure integrities.
New Analytical Techniques for Trace Constituents of Metallic and Metal-Bearing Ores
Authors: Javier-Son A
Published: March 2009

Description

This publication contains methodology and instrumentation for determination of trace constituents of metals, alloys and ores. 10 papers cover modification of instruments, special preparation of samples, optimization of matrix effects, automation, new excitation sources, and computer-controlled background corrections.
Joining of Composite Materials
Authors: Kedward KT
Published: March 2009

Description

This publication provides the reader with design information and useful data on both mechanically fastened and adhesively bonded joints. Divided into two sections: Part 1 is devoted to adhesively bonded joints, Part 2 deals with mechanically fastened joints.
Vertebrate Pest Control and Management Materials
Authors: Schafer EW , Walker CR
Published: March 2009

Description

The book presents test methods on evaluation procedures for chemicals. Devices, and other techniques used to control aquatic and terrestrial vertebrates. The areas of major interest to the reader are methods of reducing potential hazards of pesticides, including insecticides, herbicides, and microbial agents; pesticide hazard to aquatic environments; research methodologies devised primarily for small and large mammals, and practically of developing valid test methods for field use in developing countries.
Laser Induced Damage In Optical Materials: 1980
Authors: Bennett HE , Glass AJ , Guenther AH , Newnam BE
Published: March 2009

Description

The Proceedings contain the papers presented at the Twelfth Symposium on Optical Materials for High Power Lasers held at the National Bureau of Standards in Boulder, Colorado, on September 30 - October 1, 1980. The Symposium was jointly sponsored by the National Bureau of Standards, the American Society for Testing and Materials, the Office of Naval Research, the Defense Advanced Research Projects Agency, the Department of Energy, and the Air Force Office of Scientific Research. The Symposium was attended by over 150 scientists from the United States, the United Kingdom, Japan, France, and West Germany. It was divided into sessions devoted to the following topics: Materials and Measurements, Mirrors and Surfaces, Thin Films, and finally Fundamental Mechanisms. The Symposium Co-Chairmen were Dr. Harold E. Bennett of the Naval Weapons Center, Dr. Alexander J. Glass of the Lawrence Livermore Laboratories, Dr. Arthur H. Guenther of the Air Force Weapons Laboratory, and Dr. Brian E. Newnam of the Los Alamos Scientific Laboratory. They also served as editors of this report.
Guide to the Selection and Use of Electroplated and Related Finishes
Authors: Lowenheim FA
Published: March 2009

Description

This guide aims to aid the designer, engineer, and others responsible for specifying finishes in the selection of appropriate electroplated and related coatings. Metallic coatings offer a wide range of properties that provide the designer with versatility well beyond that of single substances.
MiCon 82: Optimization of Processing, Properties, and Service Performance Through Microstructural Control
Authors: Abrams H , Clark E , Hood J , Seth B
Published: March 2009

Description

14 papers comprise this book's contents and are divided among three categories:

Materials for Energy Generation Systems

Materials for Energy Transport Systems

Materials for Solar Energy Systems
Laser Induced Damage in Optical Materials: 1981
Authors: Bennett HE , Guenther AH , Milam D , Newnam BE
Published: March 2009

Description

The Proceedings contain the papers presented at the Thirteenth Symposium on Optical Materials for High Power Lasers held at the National Bureau of Standards (NBS) in Boulder, Colorado, on November 17–18, 1981. The Symposium was jointly sponsored by the National Bureau of Standards, the American Society for Testing and Materials, the Office of Naval Research, the Defense Advanced Research Projects Agency, the Department of Energy, and the Air Force Office of Scientific Research. The Symposium was attended by approximately 200 scientists from the United States, the United Kingdom, Japan, France, West Germany, the Peoples Republic of China, Sweden, and the USSR. It was divided into sessions devoted to the following topics: Materials and Measurements, Mirrors and Surfaces, Thin Films, and finally Fundamental Mechanisms. The Symposium Co-Chairmen were Dr. Harold E. Bennett of the Naval Weapons Center, Dr. Arthur H. Guenther of the Air Force Weapons Laboratory, Dr. David Milam of the Lawrence Livermore National Laboratory, and Dr. Brian E. Newnam of the Los Alamos National Laboratory. They also served as editors of this report. Dr. Alexander J. Glass of KMS Fusion acts as Conference Treasurer with Aaron A. Sanders of the National Bureau of Standards as the Conference Coordinator.
Medical Devices: Measurements, Quality Assurance, and Standards
Authors: Caceres CA , Yolken HT , Jones RJ , Piehler HR
Published: March 2009

Description

This publication provides physicians, scientists, and members of industry and government with a comprehensive overview of the role and impact of medical standards and measurements on health care. The insights, discussions, and recommendations presented in this text are representative of many individuals' contributions. However, coordination of this endeavor is due to joint participation by three primary organizations: the National Bureau of Standards, the American Medical Association, and ASTM. One central theme of this book addresses the need to integrate the physician's views with business and standards development organizations.
Stationary Gas Turbine Alternative Fuels
Authors: DeCorso SM , Clark JS
Published: March 2009

Description

This publication serves to assess the state of the art of alternative liquid and gaseous fuels for stationary gas turbine as well as providing a technical database of properties of alternative fuels specifications activities.
Cell-Culture Test Methods
Authors: Brown SA
Published: March 2009

Description

13 papers present different techniques, application of techniques, and problems of cell culture test methods.
Fatigue Mechanisms: Advances in Quantitative Measurement of Physical Damage
Authors: Lankford J , Davidson DL , Morris WL , Wei RP
Published: March 2009

Description

There are two major categories that serve to divide the book’s contents of 19 papers: Early Stages of Damage and Fatigue Crack Growth. The goal of STP 811 is to explore continuing advances in technology, which now permit more detailed quantitative measurement of fatigue damage.
Evaluation and Accreditation of Inspection and Test Activities
Authors: Schock H
Published: March 2009

Description

The purpose of STP 814 is to provide an overview for industry and professionals on approaches to evaluation and accreditation of testing and inspection activities. The major subject areas are
Fire Resistive Coatings: The Need for Standards
Authors: Lieff M , Stumpf FM
Published: March 2009

Description

Provides technical information on sprayed fire-resistive materials. Topics include fibrous material coatings for steel building columns, surface preparation of steel, test results, and inspection procedures.
Electrochemical Behavior of the Ce4+ / Ce3+ Couple in the Novel Ce- V Redox Flow Cell
Authors: Liu Yang , Xia Xi
Published: March 2009

A novel Ce4+/Ce3+- V2+/V3+ redox flow cell has been investigated. It was composed of the Ce4+/Ce3+ couple, which replaced the V5+/V4+ couple of the all6vanadium redox flow cell, and the V2+/V3+ couple. The normal potential and the kinetic parameters for anodic oxidation of Ce3+ and cathodic reduction of Ce4+ were measured. The results showed that the surface of platinum electrode was fully covered with type I oxide that inhibited the reduction of Ce4+. The reversibility of the Ce4+/Ce3+ couple improved with the increase of H2SO4 concentration, but both higher energy efficiency and coulombic efficiency were observed in 0.5 mol/dm3 H2SO4 solution. Different electrochemically active substances were found to exist at various state of charge (SOC) and the reversibility of the Ce4+/Ce3+ couple at the carbon electrode was found to be superior to platinum electrode. Periodic charge6discharge measurements were conducted under constant current and constant load with the proposed Ce6V redox flow cell. The results indicated that the coulombic efficiency remained around 90% and the discharge voltage stabilized between 1.5 and 1.2 V. But as the cycle numbers increased, the discharge capacity declined a bit and a better result might be expected by improving the separator materials and increase the concentration of electro6active materials. By comparison with the existing Fe6Cr, Fe6Ti and all6vanadium redox flow cell, the Ce6V system has a higher open6circuit voltage (OCV). And results from this preliminary study suggest that the novel Ce6V redox flow cell is a promising energy storage system and is worthy of further studies.
Single Wall Carbon Nanotube – LiCoO2 Lithium Ion Batteries
Authors: Landi Brian J. , Ganter Matthew J. , Schauerman Christopher M. , DiLeo Roberta A. , Cress Cory D. , Raffaelle Ryne P.
Published: March 2009

The electrochemical cycling performance of high purity single wall carbon nanotube (SWCNT) paper electrodes has been measured for a series of electrolyte solvent compositions. The effects of varying the galvanostatic charge rate and cycling temperature on lithium ion capacity have been evaluated between 25-100 °C. The measured reversible lithium ion capacities for SWCNT anodes range from 600-1000 mAh/g for a 1M LiPF6 electrolyte, depending on solvent composition and cycling temperature. The solid-electrolyte-interface (SEI) formation and first cycle charge loss are also shown to vary dramatically with carbonate solvent selection and illustrate the importance of solvent alkyl chain length and polarity on SWCNT capacity. SWCNT anodes have also been incorporated into full battery designs using LiCoO2 cathode composites. An electrochemical pre-lithiation sequence, prior to battery assembly, has been developed to mitigate the first cycle charge loss of SWCNT anodes. The pre-lithiated SWCNT anodes show reversible cycling at varying charge rates and depths of discharge with the cathode system. The summary of data shows that the structural integrity of individual SWCNTs is preserved after cycling, and that free-standing SWCNT paper electrodes represent an attractive material for lithium ion batteries.
Hot-die Forging of a β-stabilized γ-TiAl Based Alloy
Authors: Wallgram Wilfried , Clemens Helmut , Kremmer Sascha , Otto Andreas , Güther Volker
Published: March 2009

Because of the small “deformation window” hot-working of γ-TiAl alloys is a complex and difficult task and, therefore, isothermal forming processes are favoured. In order to increase the deformation window a novel Nb and Mo containing γ-TiAl based alloy (TNM™ alloy) was developed. Due to a high volume fraction of β-phase at elevated temperatures the alloy can be hot-die forged under near conventional conditions, which means that conventional forging equipment with minor and inexpensive modifications can be used. With subsequent heattreatments balanced mechanical properties can be achieved. This paper summarizes our progress in establishing a “near conventional” forging route for the fabrication of γ-TiAl components. The results of lab scale compression tests and forging trials on an industrial scale are included. In addition, the mechanical properties of forged and heat-treated TNM™ material are presented.
House improvements and community participation in the control of Triatoma dimidiata re-infestation in Jutiapa, Guatemala
Authors: Monroy Carlota , Bustamante Dulce Maria , Pineda Sandy , Rodas Antonieta , Castro Xochitl , Ayala Virgilio , Quiñónes Javier , Moguel Bárbara
Published: March 2009

The deterioration or absence of plaster walls in houses and poor hygienic conditions are the most important risk factors for indoor Triatoma dimidiata infestation in Guatemala. A cross-disciplinary study was conducted addressing T. dimidiata infestation, household hygiene, and housing construction. The study focused on local materials and cultural aspects (including gender roles) that could lead to long-term improvements in wall construction. A new plaster mix for walls was developed on the basis of laboratory studies on construction materials recommended by local villagers. Four villages with persistent (post-spraying) T. dimidiata infestation were studied. In two villages, an ecosystem approach was implemented, and the homeowners conducted wall improvements and household sanitation with the support of the interdisciplinary team (the ecosystem intervention). In the other two villages, a vector control approach based on insecticide spraying was adopted (traditional intervention). Both interventions were associated with a reduction in T. dimidiata infestation, but only the ecosystem approach produced important housing improvements (sanitation and wall construction) capable of preventing T. dimidiata re-infestation in the long term.
Dry Edible Bean Class and Cultivar Response to Dimethenamid and Metolachlor
Authors: Poling Kyle W. , Renner Karen A. , Penner Donald
Published: March 2009

Dry edible bean class and cultivar response to dimethenamid and metolachlor was investigated in the greenhouse and field. Kidney and cranberry cultivars, as well as a small red cultivar, were not injured by dimethenamid applied PRE at 2,100 g ai/ha in the greenhouse, whereas pinto bean tolerance varied and navy and black bean cultivars were injured by this rate. Injury to navy bean was greater in the greenhouse when dimethenamid and metolachlor were placed in the zone above and including the seed, compared with placement in the seed, root, or root plus seed zone. In an application timing field study, dimethenamid at 1,300 g/ha applied at the crook or unifoliate growth stage caused injury to navy bean, delayed maturity, and reduced seed yield. Metolachlor at 1,400 g ai/ha delayed maturity when applied at the unifoliate growth stage but did not reduce seed yield. Dimethenamid or metolachlor PRE, at 1,300 or 2,800 g ai/ha, respectively, injured navy and black bean cultivars, but seed yield was not reduced in a cultivar tolerance field study. In a planting date study, dimethenamid PRE at 2,300 g/ha reduced leaf area and delayed maturity compared with the nontreated control when pooled over five planting dates and cultivars in each of 2 yr. Metolachlor PRE at 2,800 g/ha reduced leaf area in 1 yr and delayed maturity in both years when pooled over planting dates and cultivars. If weed control and herbicide costs are comparable, metolachlor at a standard use rate is a safer choice than dimethenamid for use in navy and black bean production.
Influence of Glyphosate-Resistant Horseweed (Conyza canadensis) Growth Stage on Response to Glyphosate Applications
Authors: VanGessel Mark J. , Scott Barbara A. , Johnson Quintin R. , White-Hansen Susan E.
Published: March 2009

Infestations of glyphosate-resistant (GR) horseweed have become widespread in the eastern United States. This biotype is problematic in no-tillage production that relies extensively on glyphosate for weed control. Because horseweed is treated at various stages of growth, a greenhouse study explored rate response of glyphosate-resistant and -susceptible horseweed at three growth stages. GR horseweed was more responsive to glyphosate at the seedling stage than at the large rosette or bolting stages. A field study evaluated GR horseweed response when treated with glyphosate at soybean planting time, POST in-crop (about 45 d after planting), or both at planting and POST in-crop. There was a cumulative effect of the at-planting followed by POST in-crop glyphosate applications. When evaluating single glyphosate applications, the at-planting application was more effective at suppressing GR horseweed than a POST in-crop application. Because glyphosate cannot control GR horseweed, this biotype should be controlled with an herbicide with an alternate mode of action and applied at the most effective timing.
Pendimethalin Applications in Stale Seedbed Rice Production
Authors: Bond Jason A. , Walker Timothy W. , Koger Clifford H.
Published: March 2009

Field studies were conducted from 2005 through 2007 to determine the response of three rice cultivars (‘Cocodrie’, ‘Wells’, and ‘Lemont’) to three application timings and two formulations of pendimethalin in a stale seedbed rice production system. Pendimethalin formulated as an emulsifiable concentrate and capsule suspension was applied to rice 0, 3, and 7 d after planting. No visual injury was detected for any cultivar. Seedling density, days to 50% heading, and rice yield were not affected by pendimethalin formulation or application timing. The practice of planting cultivars with excellent seedling vigor into nondisturbed soils with greater available moisture could provide an opportunity to use pendimethalin as a preemergence herbicide for rice production.
Detecting and Mapping Four Invasive Species along the Floodplain of North Platte River, Nebraska
Authors: Narumalani Sunil , Mishra Deepak R. , Wilson Robert , Reece Patrick , Kohler Ann
Published: March 2009

Geospatial technologies are increasingly important tools used to assess the spatial distributions and predict the spread of invasive species. The objective of our research was to quantify and map four dominant invasive plant species, including saltcedar, Russian olive, Canada thistle, and musk thistle, along the flood plain of the North Platte River corridor within a 1-mile (1.6-km) buffer. Using the Airborne Imaging Spectroradiometer for Applications (AISA) hyperspectral imager (from visible to near infrared), we evaluated an image processing technique known as spectral angle mapping for mapping the invasive species distribution. A minimum noise fraction algorithm was used to remove the inherent noise and redundancy within the dataset during the classification. The classification algorithm applied on the AISA image revealed five categories of invasive species distribution including (1) saltcedar; (2) Russian olive; and a mix of (3) Canada and musk thistle, (4) Canada/musk thistle and reed canary grass, or (5) Canada/musk thistle, saltcedar, and reed canary grass. Validation procedures confirmed an overall map accuracy of 74%. Saltcedar and Russian olive classes showed producer and user accuracies of greater than 90%, whereas the mixed categories revealed accuracy values of between 35 and 74%. The immediate benefit of this research has been to provide information on the spatial distribution of invasive species to land managers for implementation of management programs. In addition, these data can be used to establish a baseline of the species distributions for future monitoring and control efforts.
Effect of Land Rolling on Weed Emergence in Field Pea, Barley, and Fallow
Authors: Lenssen Andrew W.
Published: March 2009

In the northern Great Plains, fields are land rolled after the planting of annual pulse and forage crops to push rocks back into the soil to prevent damage to harvest equipment. Field trials were conducted in 2004 and 2005 to determine if land rolling influenced weed density or biomass associated with field pea, forage barley, and summer fallow. The experiment included two planting dates, conventional and delayed, for both barley and pea. Separate fallow plots were included with each planting date. Preplant tillage was conducted with a field cultivator for all treatments. Across years, crops, and planting dates, land rolling approximately doubled densities of tumble mustard, Russian thistle, kochia, and redroot pigweed shortly after crop emergence and at harvest compared with nonrolled. Land rolling increased density of early-emerging green foxtail but density at harvest was not affected. Wild oat densities were not influenced by rolling. Weed biomass at harvest was greater after land rolling than nonrolled. Land rolling after planting decreased subsequent pea yield by 330 kg/ha, but did not influence water use or water use efficiency. Land rolling is advantageous by hastening depletion of soil broadleaf weed seed banks in forage barley, but may increase problematic broadleaf weeds in pea.
Survey of Tillage Trends Following the Adoption of Glyphosate-Resistant Crops
Authors: Givens Wade A. , Shaw David R. , Kruger Greg R. , Johnson William G. , Weller Stephen C. , Young Bryan G. , Wilson Robert G. , Owen Micheal D. K. , Jordan David
Published: March 2009

A phone survey was administered to 1,195 growers in six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina). The survey measured producers' crop history, perception of glyphosate-resistant (GR) weeds, past and present weed pressure, tillage practices, and herbicide use as affected by the adoption of GR crops. This article describes the changes in tillage practice reported in the survey. The adoption of a GR cropping system resulted in a large increase in the percentage of growers using no-till and reduced-till systems. Tillage intensity declined more in continuous GR cotton and GR soybean (45 and 23%, respectively) than in rotations that included GR corn or non-GR crops. Tillage intensity declined more in the states of Mississippi and North Carolina than in the other states, with 33% of the growers in these states shifting to more conservative tillage practices after the adoption of a GR crop. This was primarily due to the lower amount of conservation tillage adoption in these states before GR crop availability. Adoption rates of no-till and reduced-till systems increased as farm size decreased. Overall, producers in a crop rotation that included a GR crop shifted from a relatively more tillage-intense system to reduced-till or no-till systems after implementing a GR crop into their production system.
Weed Management in Peanut with Herbicide Combinations Containing Imazapic and Other Pesticides
Authors: Jordan David L. , Lancaster Sarah H. , Lanier James E. , Lassiter Bridget R. , Johnson P. Dewayne
Published: March 2009

Research was conducted in North Carolina to compare weed control by various rates of imazapic POST alone or following diclosulam PRE. In a second experiment, weed control by imazapic applied POST alone or with acifluoren, diclosulam, or 2,4-DB was compared. In a final experiment, yellow nutsedge control by imazapic alone and with the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole was compared. Large crabgrass was controlled more effectively by imazapic POST than diclosulam PRE. Common lambsquarters, common ragweed, and eclipta were controlled more effectively by diclosulam PRE than imazapic POST. Nodding spurge was controlled similarly by both herbicides. Few differences in control were noted when comparing imazapic rates after diclosulam PRE. Applying either diclosulam PRE or imazapic POST alone or in combination increased peanut yield over nontreated peanut in five of six experiments. Few differences in pod yield were noted when comparing imazapic rates. Acifluorfen, diclosulam, and 2,4-DB did not affect entireleaf morningglory, large crabgrass, nodding spurge, pitted morningglory, and yellow nutsedge control by imazapic. Eclipta control by coapplication of imazapic and diclosulam exceeded control by imazapic alone. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole did not affect yellow nutsedge control by imazapic.
Herbicide Options for Rice Cutgrass (Leersia oryzoides) Control
Authors: Norsworthy Jason K. , Scott Robert C. , Smith Kenneth L. , Still Joshua , Meier Jason
Published: March 2009

Rice cutgrass is encroaching into rice fields from ditch banks and canals, especially into continuous rice fields where tillage is limited in the Mississippi Delta region of Arkansas. Experiments were conducted to evaluate the effectiveness of various herbicides applied alone on rice cutgrass and to determine if the effectiveness of bispyribac on rice cutgrass is influenced by number of applications, adjuvant type, and adjuvant rate. Glyphosate, glufosinate, and clethodim were the most effective herbicides when applied alone; however, none of these are labeled for over-the-top application in rice. Of those herbicides that can be applied over the top of rice, imazethapyr and bispyribac were the most effective, providing 52 to 62% rice cutgrass control, albeit imazethapyr can be used only in imidazolinone-resistant rice. The addition of an adjuvant to bispyribac improved rice cutgrass control, and sequential bispyribac applications were generally superior to a single application. Methylated seed oil/organosilicone/urea ammonium nitrate adjuvant increased rice cutgrass control with bispyribac, especially when bispyribac was applied as a single application. A single application of imazethapyr, bispyribac, halosulfuron, penoxsulam, clomazone, thiobencarb, cyhalofop, propanil, quinclorac, and fenoxaprop provided less-than-acceptable control, which partially explains the difficulty that growers are experiencing in controlling rice cutgrass, especially in continuous rice production.
Weed Response to Foliar Coapplications of Glyphosate and Zinc Sulfate
Authors: Scroggs Derek M. , Miller Donnie K. , Stewart Alexander M. , Leonard B. Rogers , Griffin James L. , Blouin David C.
Published: March 2009

Field trials were conducted during 2006 and 2007 and a container study was performed twice in 2007 at the Dean Lee Research and Extension Center in Alexandria, LA to evaluate the interaction of glyphosate and zinc coapplied to selected weeds. Across all experiments, no differences in either visible weed control or weed fresh weight were detected among glyphosate formulations. In the field studies, weed control was greatest when glyphosate was applied alone, in which case control of barnyardgrass, browntop millet, and Palmer amaranth ranged between 93 and 95%. When glyphosate was coapplied with formulations of zinc, control of the aforementioned weed species was reduced to 39, 39, and 45%, respectively. Visual estimates of weed control in the container studies showed glyphosate performance to be the highest (82 to 98%) in the absence of zinc for control of barnyardgrass, browntop millet, johnsongrass, ivyleaf morningglory, and redroot pigweed. Across all weed species, control was reduced 43 to 59% when zinc was coapplied with glyphosate. Similar results were noted in reduction of weed fresh weights. Results indicate that glyphosate-based weed control is reduced when coapplied with the zinc products at their current use rates. Producers should be aware of this antagonism and these coapplications should not be recommended.