bluuebunny/crossref_metadata_2025 huggingface dataset:
Implications of Molecular Speciation and Topology of Environmental Metals: Uptake Mechanisms and Toxicity of Organotins
Authors: Brinckman FE , Olson GJ , Blair WR , Parks EJ
Published: February 2009

This paper compares predictions of environmental fate and effect parameters derived from quantitative structure-activity relationships (QSAR) using estimates of molecular total surface area (TSA) with experimental data. Organotins are used as an example. In addition, a simple linear free-energy relationship with TSA is demonstrated to be applicable to organotin aqueous solubility, chromatographic retentivity, octanol-water partition coefficients and bacterial uptake, and aquatic toxicity. New measurement methodology providing nondestructive optical imaging in vivo of tin employing a fluorescent, tin-specific ligand (3-hydroxyflavone) is used to evaluate a likely mechanism of uptake for triorganotins on cells. Finally, the laboratory results are extended to a preliminary appraisal of environmental persistence of tributyltin, which involves both uptake and degradation processes.
Determination of the Nature of Neutron Irradiation-Induced Dislocation Loops in Magnesium Using Electron Irradiation in the Transmission Electron Microscope
Authors: Wolfenden A
Published: February 2009

Magnesium single crystals were irradiated to 2.1 × 1021 neutrons (n)/cm2 (E > 0.1 MeV) near 450 K, one set of specimens being under a compressive stress of 80 MPa applied in the c-direction. A transmission electron microscopy (TEM) investigation of the crystals irradiated under load showed that the neutron damage consisted of dislocation loops. Under in situ electron irradiation in the TEM at 200 kV, some of these loops were observed to shrink. It was deduced that the shrinking loops were of the vacancy type, which is consistent with theoretical predictions [1] of the influence of an external compressive stress on dislocation loop formation during irradiation.
Neutron Irradiation-Induced Defect Structures in Zirconium
Authors: Jostsons A , Kelly PM , Blake RG , Farrell K
Published: February 2009

A transmission electron microscope (TEM) was used to study the neutron irradiation-induced defect structures in zirconium from various sources irradiated to fluences up to 1.3 × 1025 neutrons (n)/m-2 > 0.1 MeV and temperatures in the range 478 to 823 K. Below 673 K the predominant form of damage consists of ⅓ 〈1120〉 dislocation loops. At higher irradiation temperatures, depending on specimen purity, the defects may include faulted ⅙ 〈2023〉 loops and voids in addition to the perfect ⅓〈1120〉 loops. The temperature regime of the stability of the various defects was defined. Quantitative measurements showing the effect of irradiation temperature and specimen purity are presented and discussed.
Dependence of Cavity Nucleation Density Upon Gas Implantation Rate and Its Importance in Dual-Beam Irradiation Conditions
Authors: Hayns MR , Wood MH , Bullough R
Published: February 2009

We have previously shown, using the rate theory of void swelling, that it should be possible to reproduce the evolution of the high-temperature gas-assisted void swelling peak observed in neutron-irradiated 316 austenitic steel using the planned dual-beam irradiation facilities. However, the rate-theory formulation does not include a cavity nucleation model; hence cavity densities obtained from experiments with preinjection of gas before heavy ion irradiation are traditionally input to the model. Furthermore, swelling is known to be sensitive to cavity densities and no values are presently available from dual-beam experiments.

Therefore, in the present study we calculate cavity densities using a homogeneous nucleation model previously developed for fission gas bubbles in nuclear fuels, and compare the calculated void swelling using these cavity densities with the swelling results previously obtained using the preinjected experimental values.
Development of Physically Based Void Swelling Equations for Engineering and Design Use
Authors: Hayns MR , Bullough R
Published: February 2009

The physical understanding of void swelling in cold-worked 316 austenitic steel obtained from the rate-theory model has been distilled into a semi-empirical equation designed specifically for engineering use. Several physically complicated variables have been reduced to fitting parameters which reflect only their original meanings. The essential role of the void density and stress are highlighted. The equation has been incorporated into the fuel element modeling code FRUMP, and calculations of actual pin performance are used to assess the usefulness of the model.
Radiation-Induced Segregation in Nickel-Silicon Alloys
Authors: Rehn LE , Okamoto PR , Potter DI , Wiedersich H
Published: February 2009

Radiation-induced segregation was studied in a nickel 1 atomic percent silicon (Ni-1Si) alloy after irradiation at ∼525°C with 3-MeV58Ni+ ions. Postirradiation profiles of alloy composition as a function of depth from the irradiated surface were obtained by standard Auger techniques and ion-sputtering at room temperature. Rapid segregation of silicon toward the irradiated surface was observed. The solubility limit of silicon in nickel was reached at the surface after a dose of only 0.05 displacements per atom (dpa). Segregation continued to increase up to the highest dose (6.5 dpa) investigated. Precipitation of Ni3Si occurred at the external surface and internally on dislocation loops. The experimental results are compared with calculations using the Johnson-Lam segregation model and a set of parameters that was used previously to fit the temperature dependence of radiation-induced segregation in Ni-1Si.
An Example of Precipitate Stability in Reactor-Irradiated Nimonic PE16
Authors: Gelles DS
Published: February 2009

Iron-based precipitation-strengthened superalloys are being considered for use as structural materials in fast breeder reactors (FBR's). Appropriate application of these materials requires an understanding of the microstructural stability of precipitation-strengthening phases in the radiation damage environment. Recent theories modeling precipitate stability in-reactor balance two competing effects: (1) radiation-enhanced coarsening and (2) cascade-induced recoil or disordering dissolution. A direct consequence of these theories is the development of a stable precipitate particle size. Thus, it is predicted that microstructures developed at high neutron fluences will be insensitive to the microstructure prior to irradiation. Alloy properties such as swelling and creep should be unaffected by variations in the starting precipitate microstructure.

A test of these concepts is presented. Nimonic PE16, a γ' [Ni3(Al,Ti)] precipitate-strengthened alloy under consideration for fast reactor structural applications, has been reactor irradiated in three heat-treatment conditions: solution treated, aged, and overaged. After irradiation at 600°C to 5.4 × 1022 neutrons/cm2 (E > 0.1 MeV), or about 27 displacements per atom (dpa), specimens were characterized for ³' precipitate stability by transmission electron microscopy. The precipitate microstructures after irradiation were found to be very sensitive to heat treatment prior to irradiation. The precipitates present prior to irradiation remained stable. However, additional precipitation occurred in-reactor for each of the specimen conditions examined. The in-reactor ³ ' precipitation process decorated such microstructural features as voids, dislocations, and carbide precipitates. Therefore, it is apparent that a maximum stable precipitate particle size does not exist in this alloy under these irradiation conditions. It should be noted that 5.4 × 1022 n/cm2 represents only 25 percent of the targeted goal fluence for potential advanced FBR cladding and duct applications; however, these results can be considered to provide a realistic estimate of microstructural alterations to be expected at goal fluences.

It is apparent that the generally accepted models for precipitate stability during reactor irradiation do not successfully predict the experimental observations. Cascade-induced dissolution does not reduce the maximum stable precipitate particle size. Interpretations of early experimental results which indicated an invariant mean particle size after irradiation appear to be in error, because further precipitation in-reactor was not adequately considered. A more acceptable model for precipitate stability in-reactor must take cognizance of the fact that precipitate volume fractions change as a function of temperature, that solute segregation occurs at many microstructural features, probably in a dose-dependent manner, and that cascade dissolution of precipitates is not a dominant mechanism.
Evaluation of Commercial Production A533-B Steel Plates and Weld Deposits with Extra-Low Copper Content for Radiation Resistance
Authors: Hawthorne JR , Koziol JJ , Byrne ST
Published: February 2009

A cooperative research program by the U.S. Nuclear Regulatory Commission (NRC), Combustion Engineering, Inc., (CE), and the Naval Research Laboratory (NRL) has explored trends in radiation effects for commercially produced ASTM A533-B steel plates, weld deposits, and weld heat-affected zones, depicting three levels of control over impurity copper content. The primary objective was to establish the trend of improved 288°C (550°F) radiation resistance with progressive reductions in allowable copper content. An overall objective was to develop information assisting the formulation of special specifications for steels for nuclear service and the delineation of associated embrittlement trends for reactor vessel design and operation. This report describes investigations on Series 3 materials, which represent optimum steelmaking practice, and a limitation on copper content of 0.06 percent copper maximum.

Radiation resistance was assessed from Charpy-V (Cv) notch ductility changes with fluences of ∼5 to 7 × 1019 neutrons (n)/cm2 > 1 MeV. All Series 3 materials exhibited high resistance to radiation in terms of both transition temperature elevation and upper-shelf degradation. Typically, the postirradiation C v 41 J (30 ft-lb) transition temperature elevation was less than 56°C (100°F). An independent effect of nickel content on radiation resistance was not observed for weld metal containing a high nickel content (≈ 1 percent nickel) and an extra-low copper content (0.05 percent copper).

Comparisons of Series 3 and Series 2 data trends revealed that the specification of an extra-low copper content (0.06 percent copper maximum) as opposed to a low copper content (0.10 percent copper maximum) does not provide a substantial increase in radiation resistance for A533-B materials for the fluence range investigated. Accordingly, the study has confirmed that new ASTM and American Welding Society (AWS) supplemental specifications on copper content for nuclear service are sufficiently restrictive to optimize 288°C (550°F) radiation resistance of A533 plates and weld deposits for most projected vessel fluence conditions.
Irradiation Behavior of Nickel-Chromium-Molybdenum Type Weld Metal
Authors: Klausnitzer EN , Gerscha A , Leitz C
Published: February 2009

The irradiation and recovery behavior of a nickel-chromium-molybdenum type weld metal with 0.27 weight percent copper was examined mainly with tension, impact, drop-weight, and fracture-mechanics specimens up to a thickness of 100 mm. After irradiation at about 6 × 1019 neutrons (n)/cm2 (E > 1 MeV) at 310°C, the impact tests show larger temperature shift than for the drop-weight and fracture-mechanics tests. Recovery annealing was done at 350 (only hardness measurements), 400, 450, 500, and 550°C. Reasonable recovery effects were observed after annealing for 60 h at 450°C. For complete recovery, annealing between 500 and 550°C is necessary. Direct transfer of the test results to light water reactors is not possible, as the irradiation temperature of the specimens was 30 K higher than the operating temperature of reactor pressure vessels.
Exploratory Investigations of Cyclic Irradiation and Annealing Effects on Notch Ductility of A533-B Weld Deposits
Authors: Hawthorne JR , Watson HE , Loss FJ
Published: February 2009

Postirradiation heat treatment (annealing) is being investigated as a possible method for the periodic relief of radiation embrittlement to reactor vessel steels. This report describes a study of the Charpy-V (CV) notch ductility of two representative A533-B weld deposits under two full annealing and reirradiation cycles. The welds were specially chosen for their high sensitivity to radiation effects and for their difference in as-fabricated CV upper-shelf energy levels. Notch ductility properties were determined at each phase in the irradiation-annealing sequence. Heat-treatment temperatures were selected to represent two heat-treatment options open for vessel annealing.

The results demonstrate that a 399°C (750°F), 168-h heat treatment is highly effective for reducing radiation embrittlement accrual in service; in contrast, a 343°C (650°F), 168-h heat treatment is shown to be of little benefit for the fluence conditions investigated. A greater rate of radiation embrittlement was observed for the heat-treated material (both conditions) compared with nonheat-treated material. The investigations also revealed a significant difference between upper-shelf energy and transition temperature response to heat treatment.
Radiation Damage Effects in 16-MeV Proton and 14-MeV Neutron Irradiated Nickel and Niobium
Authors: Jones RH , Styris DL , Bradley ER
Published: February 2009

The high-energy (>10 keV) recoil spectra induced in metals by 16-MeV protons have been predicted to be similar to that induced by 14-MeV neutrons. The damage induced in nickel and niobium by 16-MeV protons and 14-MeV neutrons has been evaluated by transmission electron microscopy and flow stress measurements.

Nickel and niobium wires (0.18 mm diameter) and foils have been irradiated with 16-MeV protons from the Tandem Van de Graaff at the Nuclear Physics Laboratory of the University of Washington and 14-MeV neutrons from the Rotating Target Neutron Source I at Lawrence Livermore Laboratory. These irradiations were performed on specimens that were prepared and tested in a similar manner.

The damage induced in nickel and niobium at 20°C by 16-MeV protons and 14-MeV neutrons was found to exhibit many similarities with respect to the size and density of defect clusters. The yield strength increases were found to be slightly higher in the proton-irradiated materials as a function of particle fluence.
Radiation Damage Function Analysis
Authors: Gold R , Lippincott EP , McElroy WN , Simons RL
Published: February 2009

Considerable efforts have been expended to measure radiation damage effects on materials. These radiation damage studies can generally be justified by their impact upon nuclear reactor design and operation. However, radiation damage experiments can be difficult to interpret. A large number of parameters, including temperature, material variables, neutron spectrum, and fluence, are entailed in the evaluation of radiation damage data. The general case is further complicated as each of these variables may change with time.

The concept of a damage function was introduced some time ago to relate radiation damage to the neutron spectrum. This concept now forms the basis of conventional damage function analysis. The damage function in this conventional description is related to the “cross section” for damage at each neutron energy. However, this conventional formulation is unduly restrictive.

In order to construct a rigorous description of damage function analysis, a generalized damage function is postulated which includes not only neutron energy dependence, but also time dependence. Other important material variables as well as fluence are also considered to be explicit variables of the generalized damage function.

A number of important implications of this generalized integral representation are discussed. In order to provide guidance and insight in this investigation, radiation dosimetry analysis is used as a fundamental analog. It is shown that the generalized damage function is unique. Additional characteristics of generalized damage functions are determined by considering constraints imposed by physical requirements and conditions, such as nonnegativity, continuity, and boundedness.

For actual application it is necessary to reduce generalized radiation damage function analysis to simple models. Various assumptions that can be invoked to provide these simplified models are discussed, including separation-of-variables and restriction to steady-state irradiation conditions. In particular, it is shown that conventional damage function analysis follows directly from generalized damage function analysis upon the introduction of these simplified models.

Although some success may be possible for these simplified models, the complexity of this integral representation of generalized radiation damage function analysis cannot be overemphasized. Alternative formulations of radiation damage function analysis should be investigated with the hope that such efforts will supply not only further insight, but descriptions of considerably less complexity.
Solid-State Track Recorder Materials for Use in Light-Water-Reactor Pressure Vessel Surveillance Exposures
Authors: Gold R , Roberts JH , Ruddy FH
Published: February 2009

Solid-state track recorders (SSTR) have been used extensively in reactor neutron dosimetry. Further applications of SSTR in the U.S. breeder reactor, light water reactor, and magnetic fusion energy reactor programs have been planned. Extension of high-accuracy SSTR techniques to high-fluence irradiations requires careful attention to many experimental details. One very important aspect of this work is the selection of materials that comprise the SSTR.

A variety of solid state track recorder materials has been examined for light-water-reactor pressure vessel surveillance applications. Emphasis has been placed on SSTR characteristics which are most relevant to high-fluence irradiations. The SSTR materials investigated include eleven different types of muscovite mica from worldwide geographical locations and different commercial suppliers, synthetic and natural quartz crystals, and quartz glass. Activatable impurities are appreciable only in the case of mica SSTR, and relative isotopic impurity concentrations are reported. Fissionable impurity concentrations in mica and quartz are also reported. The properties of mica and quartz SSTR subjected to high-fluence (3 × 1021 neutrons (n)/cm2), high-temperature [427°C (800°F)] irradiations have been investigated. Recommendations regarding suitable types of mica and quartz are made.
Microstructure and Tensile Properties of Heavily Irradiated 1100-0 Aluminum
Authors: Farrell K , Richt AE
Published: February 2009

Microstructural changes and the resulting tensile properties of commercial-purity (1100 grade) aluminum were measured after neutron irradiations up to 1.4 × 1027 neutrons (n)/m2 (E > 0.1 MeV) and 2.3 × 1027 n/m2 (E > 0.025 eV) at ∼ 328 K (0.35 Tm), corresponding to displacement levels of 200 displacements per atom and the generation of 5.5 weight percent silicon. The material displayed up to about 8 percent swelling. Microstructural features included dislocation tangles, a precipitate of elemental silicon, and heterogeneously distributed voids coated with silicon. Alongside grain boundaries were sheets of large voids. These microstructural features are shown to be responsible for increasing the 0.2 percent flow stress and the ultimate tensile strength at 323 K by factors of 5 and 3 to values of 220 and 250 MPa, respectively, and by factors of 6.5 and 3.5 to about 190 MPa at 423 K (0.45 Tm). Elongation was reduced at 323 K from 32 percent to a plateau at 12 percent in the fluence range 4 × 1025 n/m2 to 7 × 1026 n/m2 (>0.1 MeV), followed by a sharp fall to 4 percent at the highest fluences, the latter concomitant with a change to intergranular-type fracture. In the 423 K tests the elongation declined from 56 to 4 percent at the highest fluences where intergranular-type fracture prevailed. Most of this loss in ductility is accountable in terms of dispersion hardening through changes in strain-hardening parameters. It is suggested that the apparent intergranular fractures are caused by tearing of sheets of voids adjacent to grain boundaries.
Fracture Toughness of Irradiated AISI 304 and 316L Stainless Steels
Authors: Dufresne J , Henry B , Larsson H
Published: February 2009

The fracture toughness of AISI 304 and 316L stainless steels and their welds irradiated to 7 × 1025 neutrons (n)/m2 (50 percent of this was at E > 0.1 MeV) was investigated on 10- and 20-mm-thick three-point bend specimens. Measurements of critical values of the J-integral, Jc, and the crack-opening displacement, δc, defined at the onset of stable crack growth, were performed at 20 and 400°C. The electric potential method was adapted to hot-cell operation for the detection of the initiation point. Drastic reductions of fracture toughness occur when combining welding, irradiation, and high temperature. As an example, the value δc = 0.51 mm of base-material nonirradiated specimens tested at 20°C drops to 0.011 mm for welded irradiated specimens tested at 400°C. The consequences on liquid metal fast breeder reactor (LMFBR) structural design are illustrated in the case of the French LMFBR Super Phénix.
Fracture Toughness of Irradiated Nimonic PE16 at High Temperatures
Authors: Nicholson RD , Jones RB
Published: February 2009

Fracture toughness results are presented for the nickel-base austenitic alloy Nimonic PE16 following hot tension tests on irradiated compact-tension specimens 6.5 mm thick and data analysis using linear elastic and post-yield techniques.

Postirradiation fracture toughness values decreasing from ∼70 to 10 MNm-3/2 were found between 550 and 800°C for specimens with yield strengths of 380 to 517 MNm-2 after irradiation at ∼500 and 700°C to 4.5 to 10.2 × 1020 (thermal) neutrons (n)/cm-2 and 17- to 24-ppm helium. Below 550°C the specimens failed with gross plastic deformation.

The deterioration in fracture toughness was attributed to helium bubble growth and coalescence on stressed grain boundaries. This conclusion was supported by the detection of small closely spaced helium bubbles in grain boundaries of an irradiated PE16 tension specimen fractured at 700°C and by estimates of the growth stress, growth kinetics, and fracture strain for the observed bubble morphology.

The fracture toughness values have been used to calculate critical defect sizes in representative defect geometries comprising a notch in a round bar or a semi-elliptical defect in a plate. For low-toughness material, small critical defect sizes of ∼0.5 mm were found at stress levels between 0.2 and 0.6 of the ultimate tensile strength. These results emphasize the close attention required to proper design, manufacture, and inspection in order to avoid such small defects together with possible limitations to the operation of components in the low-toughness region.
Effects of Irradiation Creep on Ex-Reactor Mechanical Properties
Authors: Duncan DR
Published: February 2009

Irradiation creep of reactor core components is usually considered nondamaging. This concept has had no experimental verification, reducing confidence in its application to reactor design. The work reported herein was intended to test the damaging nature of irradiation creep. Material used was 20 percent cold-worked AISI 316 stainless steel tubing of 5.84-mm outside diameter and 5.08-mm inside diameter. The tubing specimens had been irradiated with stress and with zero stress to provide varying amounts of irradiation creep. A transient burst test was used to assess creep effects. This test imposes a constant stress and an increasing constant rate temperature ramp on a tubular specimen until rupture occurs. Results demonstrated that the specimens with irradiation creep failed at temperatures similar to those without irradiation creep, indicating comparable cladding strengths. Strain results were less clear, but no major reductions were seen. Thus, irradiation creep to the magnitudes investigated was nondamaging.
A Comparison of Fuel Pin Deformations with Pressurized Tube Creep Tests
Authors: Taylor JP , Gilbert ER , Lovell AJ
Published: February 2009

Fuel pins are a key component in the fast breeder reactor (FBR), and the economical performance of the reactor depends upon the behavior and life of fuel pin assemblies. One of the limiting phenomena in fuel pin and assembly performance is deformation. A thermomechanical performance code “SIFAIL” is being used at the Hanford Engineering Development Laboratory (HEDL) to predict fuel cladding deformation. SIFAIL utilizes empirical descriptions of cladding strain as a function of temperature, stress, and neutron fluence to predict fuel pin profiles. The equations are derived primarily from in-reactor tests on tubes pressurized with an inert gas and irradiated under conditions of constant temperature and stress. These equations were modified in SIFAIL to account for the variations in temperature and stress with time which occur in fuel pins. It is the purpose of these investigations to develop analytical methods which can be used to design fuel pins with optimum long-life performance.

Equations were developed to describe the in-reactor creep behavior for two different classes of AISI 316 stainless steel tubing, a developmental class for the fast test reactor (FTR) and the FTR first-core tubing. The behavior of these two tubing classes was sufficiently different that two distinctly separate equations were required to describe their in-reactor creep behaviors.

The results of the analyses showed several features. First of all, the SIFAIL performance code predicted the experimental fuel cladding strains to within a mean value of +0.03 percent using fission gas pressure as the only loading mechanism. This indicates that mechanical interaction between the fuel pellets and the stainless steel cladding in addition to other loading mechanisms generated less that 0.1 percent mean strain. Secondly, there appeared to be little correlation between creep and swelling. The variability in swelling among fuel pins was not reflected in the variability of in-reactor creep. Thirdly, the use of an in-reactor creep model which relied on a steady-state swelling rate to predict the creep rate (swelling-enhanced creep model) underpredicted the fuel pin cladding strains by approximately 50 percent. Finally, the deformations in fuel pin cladding reflected similar differences between the developmental class and the first-core class as found in the pressurized tube creep results for these two classes of tubing.
Reduction of Irradiation-Induced Creep by Point-Defect Trapping
Authors: Mansur LK , Wolfer WG
Published: February 2009

The theory of point-defect trapping has been applied to predict the effect of solutes on the steady-state dislocation climb creep rate. A range of parameters of experimental relevance is considered. Vacancy loops generated in the cascades produced by heavy particles are included in the formalism. It is shown that the effect of vacancy loops on the creep rate is mathematically equivalent to a simultaneous reduction in the vacancy trapping rate at solutes as well as in the free point-defect generation rate and recombination coefficient. These parameters are reduced by the ratio of the sink strength without vacancy loops to the total sink strength. It is found that solute trapping and vacancy loops may reduce the unperturbed creep rates by up to an order of magnitude for the parametric range considered.
Irradiation Creep Due to Stress-Induced Preferred Absorption of Point Defects in Zirconium Single Crystals
Authors: Woo CH
Published: February 2009

A study of irradiation creep due to stress-induced preferred absorption of point defects in zirconium single crystals is presented. By using a previously obtained formula for the dislocation climb velocity we derive general expressions for the creep rate due to dislocation climb and the subsequent glide allowed by the climb, taking into account the anisotropy of the dislocation structure. These formulas are then applied to the case of a single crystal of zirconium. We find that the creep rate is very sensitive to the stress direction relative to the c-axis. If θ is the angle between the stress direction and the c-axis, then the creep rate is proportional to sin4θ. We_find also that if the deformation dislocations are not evenly distributed in the three <1120> directions, the creep rate may increase or decrease when the density of the deformation dislocation increases.
Low Cycle Fatigue
Authors: Solomon HD , Halford GR , Kaisand LR , Leis BN
Published: February 2009

Description

The symposium on Low Cycle Fatigue: Directions for the Future was held in Bolton Landing (on Lake George), New York, 30 September to 4 October 1985. It was sponsored by ASTM Committee E09 on Fatigue, with support from the Hudson-Mohawk Chapter of AIME and the Eastern New York Chapter of ASM. The symposium was organized by Harvey D. Solomon (chairman), Brian Leis, Gary Halford, and Leonard Kaisand.
Ground-Water Contamination: Field Methods
Authors: Collins AG , Johnson AI
Published: February 2009

Description

Reviews and evaluates field methods used to study ground-water contamination. 30 peer-reviewed papers examine:

• ground-water sampling and sampling in unsaturated soils

• well-drilling (construction and monitoring)

• geophysical exploration

• quality assurance

• soil permeability

• and nonpoint source investigations.

Some case histories are included: for hydrologic engineer, hydrogeologists, soil scientists, and geotechnical engineers.
Computerization and Data Management in the Metals Analysis Laboratory
Authors: Worthington MA , Bottone NL
Published: February 2009

Description

The purpose of this book is to guide chemists in both selecting the appropriate hardware and software, and using it to interface laboratory instruments, log in samples, process and file data, disseminate information, monitor quality assurance parameters, and general management reports.
Mechanics of Fatigue Crack Closure
Authors: Newman JC , Elber W
Published: February 2009

Description

Covers fatigue crack closure from materials characterization to practical application in industry. Peer reviewed papers provide information and experiences on new crack-closure measurement techniques, advanced crack-closure analysis methods, and practical applications of the crack-closure concept to predict crack-propagation lives of aerospace and automotive components under complex load histories.
Functional Testing of Aquatic Biota for Estimating Hazards of Chemicals
Authors: Cairns J , Pratt JR
Published: February 2009

Description

Fifteen peer-reviewed papers emphasize the use of biological function couple with biological structure information to predict the effects of anthropogenic stress on aquatic communities and ecosystems.
Waste Testing and Quality Assurance
Authors: Friedman D
Published: February 2009

Description

12 papers focus on testing methodology and quality assurance practices that are being developed for or applied to the Resource Conservation and Recovery Act and the Comprehensive Environmental Response, Compensation, and Liability Act. The papers discuss leach ability estimation, data quality assurance, and analytical method development and evaluation.
Men are Missing from African Family Planning
Authors: Frost Ashley E. , Dodoo F. Nii-Amoo
Published: February 2009

Roughly 50 years ago it became clear that women across the developing world were bearing more children than they wanted.

Poor access to modern contraception meant women couldn't properly plan their families or prevent unwanted pregnancies. Demographers and policy makers foresaw a potentially catastrophic global population explosion, and significant financial investments in family planning programs in Africa, Asia, and Latin America followed.
The Synthetic Situation: Interactionism for a Global World
Authors: Cetina Karin Knorr
Published: February 2009

Presented as the Distinguished Lecture at the annual meeting of the Society for the Study of Symbolic Interaction in Boston, Massachusetts, on August 1, 2008, this article rethinks central assumptions of the interaction order as conceptualized by Goffman and others with respect to global domains of activity.1 It proposes two new concepts, that of the synthetic situation and that of time transactions. Synthetic situations are situations that include electronically transmitted on‐screen projections that add informational depth and new response requirements to the “ecological huddle” (Goffman 1964:135) of the natural situation. Global situations invariably include such components; we also find that temporal forms of integration may substitute for joint territoriality of copresence in the natural situation. Based on research on global currency trading and other empirical examples, I identify four types of synthetic situations and describe the synthetic situation's informational character, its ontological fluidity, and the phenomenon that synthetic situations may become role‐others for participants. I outline the response system of synthetic situations, sketching out the concepts of response presence and its implications in this context as well as the importance of embodiment. I also discuss time transactions and the idea of fatefulness as a symbolic charge linked to the synthetic components of the situation.
The Impact of Environmental Heterogeneity on Genetic Architecture in a Wild Population of Soay Sheep
Authors: Robinson Matthew R , Wilson Alastair J , Pilkington Jill G , Clutton-Brock Tim H , Pemberton Josephine M , Kruuk Loeske E B
Published: February 2009

This work demonstrates that environmental conditions experienced by individuals can shape their development and affect the stability of genetic associations. The implication of this observation is that the environmental response may influence the evolution of traits in the wild. Here, we examined how the genetic architecture of a suite of sexually dimorphic traits changed as a function of environmental conditions in an unmanaged population of Soay sheep (Ovis aries) on the island of Hirta, St. Kilda, northwest Scotland. We examined the stability of phenotypic, genetic, and environmental (residual) covariance in males during the first year of life between horn length, body weight, and parasite load in environments of different quality. We then examined the same covariance structures across environments within and between the adult sexes. We found significant genotype-by-environment interactions for lamb male body weight and parasite load, leading to a change in the genetic correlation among environments. Horn length was genetically correlated with body weight in males but not females and the genetic correlation among traits within and between the sexes was dependent upon the environmental conditions experienced during adulthood. Genetic correlations were smaller in more favorable environmental conditions, suggesting that in good environments, loci are expressed that have sex-specific effects. The reduction in genetic correlation between the sexes may allow independent evolutionary trajectories for each sex. This study demonstrates that the genetic architecture of traits is not stable under temporally varying environments and highlights the fact that evolutionary processes may depend largely upon ecological conditions.
Duplication, Selection and Gene Conversion in aDrosophila mojavensisFemale Reproductive Protein Family
Authors: Kelleher Erin S , Markow Therese A
Published: February 2009

Protein components of the Drosophila male ejaculate, several of which evolve rapidly, are critical modulators of reproductive success. Recent studies of female reproductive tract proteins indicate they also are extremely divergent between species, suggesting that reproductive molecules may coevolve between the sexes. Our current understanding of intersexual coevolution, however, is severely limited by the paucity of genetic and evolutionary studies on the female molecules involved. Physiological evidence of ejaculate–female coadaptation, paired with a promiscuous mating system, makes Drosophila mojavensis an exciting model system in which to study the evolution of reproductive proteins. Here we explore the evolutionary dynamics of a five-paralog gene family of female reproductive proteases within populations of D. mojavensis and throughout the repleta species group. We show that the proteins have experienced ongoing gene duplication and adaptive evolution and further exhibit dynamic patterns of pseudogenation, copy number variation, gene conversion, and selection within geographically isolated populations of D. mojavensis. The integration of these patterns in a single gene family has never before been documented in a reproductive protein.
Impact of Postnatal Corticosteroid Use on Neurodevelopment at 18 to 22 Months' Adjusted Age: Effects of Dose, Timing, and Risk of Bronchopulmonary Dysplasia in Extremely Low Birth Weight Infants
Authors: Wilson-Costello Deanne , Walsh Michele C. , Langer John C. , Guillet Ronnie , Laptook Abbot R. , Stoll Barbara J. , Shankaran Seetha , Finer Neil N. , Van Meurs Krisa P. , Engle William A. , Das Abhik ,   for the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network
Published: February 2009

OBJECTIVE. Postnatal steroid use decreases lung inflammation but increases impairment. We hypothesized that increased dose is associated with increased neurodevelopmental impairment, lower postmenstrual age at exposure increases impairment, and risk of bronchopulmonary dysplasia modifies the effect of postnatal corticosteroid.

METHODS. Steroid dose and timing of exposure beyond 7 days was assessed among 2358 extremely low birth weight infants nested in a prospective trial, with 1667 (84%) survivors examined at 18 to 22 months' postmenstrual age. Logistic regression tested the relationship between impairment (Bayley Mental Developmental Index/Psychomotor Developmental Index of <70, disabling cerebral palsy, or sensory impairment), total dose (tertiles: <0.9, 0.9–1.9, and ≥1.9 mg/kg), and postmenstrual age at first dose. Separate logistic regression tested effect modification according to bronchopulmonary dysplasia severity (Romagnoli risk > 0.5 as high risk, n = 2336 (99%) for days of life 4–7).

RESULTS. Three hundred sixty-six (16%) neonates were steroid-treated (94% dexamethasone). Treated neonates were smaller and less mature; 72% of those treated were at high risk for bronchopulmonary dysplasia. Exposure was associated with neurodevelopmental impairment/death. Impairment increased with higher dose; 71% dead or impaired at highest dose tertile. Each 1 mg/kg dose was associated with a 2.0-point reduction on the Mental Developmental Index and a 40% risk increase for disabling cerebral palsy. Older age did not mitigate the harm. Treatment after 33 weeks' postmenstrual age was associated with greatest harm despite not receiving the highest dose. The relationship between steroid exposure and impairment was modified by the bronchopulmonary dysplasia risk, with those at highest risk experiencing less harm.

CONCLUSIONS. Higher steroid dose was associated with increased neurodevelopmental impairment. There is no “safe” window for steroid use in extremely low birth weight infants. Neonates with low bronchopulmonary dysplasia risk should not be exposed. A randomized trial of steroid use in infants at highest risk is warranted.
Efficient Channels of Energy Transfer in High Light Yield LuI3:Ce Scintillator
Authors: Knizhnik Andrey , Vasil'ev Andrey N. , Iskandarova Inna M. , Scherbinin Andrey V. , Markov Igor , Bagatur'yants Alexander A. , Potapkin Boris , Srivastava Alok , Vartuli James , Duclos Steven
Published: February 2009

The extremely high scintillation efficiency of lutetium iodide doped by cerium is explained as a result of several factors controlling the energy transfer from the host matrix to activator, two of which are investigated in the present paper. The first one is the increase of the efficiency of energy transfer from self-trapped excitons to cerium ions in the row LuCl3-LuBr3-LuI3. The STE structure and the efficiency of STE to cerium energy transfer are verified by cluster ab initio calculations. We propose and theoretically validate the possibility of a new channel of energy transfer to excitons and directly to cerium, namely the Auger process when Lu 4f hole relaxes to the valence band hole with simultaneous creation of additional exciton or excitation of cerium. This process should be efficient in LuI3, and inefficient in LuCl3. In order to justify this channel we perform calculations of density of states using a periodic plane-wave density functional approach. The performed estimations theoretically justify the high LuI3:Ce3+ scintillator yield.
Bistable Electrical Switching and Rewritable Memory Effect in a Thin Film Acrylate Copolymer Containing Carbazole-Oxadiazole Donor–Acceptor Pendant Groups
Authors: Teo Eric , Ling Qidan , Lim Siew Lay , Neoh Koon Gee , Kang En-Tang , Chan Daniel Siu Hung , Zhu Chunxiang
Published: February 2009

The molecular conformation-dependent write-once read-many-times (WORM) memory based on an acrylate polymer containing pendant carbazole (donor) groups is transformed into a flash (rewritable) memory when acrylate units containing pendant oxadiazole (acceptor) groups are incorporated to form a copolymer. The as-fabricated device based on the acrylate copolymer containing carbazole-oxadiazole donor-acceptor pendant groups is in its low conductivity state and can be written to a high conductivity state at a threshold voltage of -1.8 V. The high conductivity state can be switched (erased) to the low conductivity state with a positive bias of 3.6 V. The device exhibits a high ON/OFF current ratio of 103 at a read voltage of -1 V. This rewritable polymer memory can be programmed and erased repeatedly with good accuracy. The copolymer is potentially useful for application in flash memory devices.
Laser Direct Drawing of Silver Microwiring on a Double-Decker-Shaped Polysilsesquioxane Film using Silver Nanoparticle Ink
Authors: Aminuzzaman Mohammod , Watanabe Akira , Miyashita Tokuji
Published: February 2009

Recent years have witnessed an explosion of interest in the application of polymers as the substrates for various electronic and display devices. The advantages of polymers are their mechanical flexibility, light weight, enhanced durability, roll-to-roll fabrication and low cost compared with rigid materials (such as silicon and glass). Hybrid polymers have drawn great attention because they offer the opportunity to prepare high-performance multifunctional advanced materials through the combination of properties of organic and inorganic segments. Recently, a new approach to construction of nanohybrid materials based on polyhedral oligomeric silsesquioxne (POSS) as an inorganic moiety has attracted a lot of interest. Double-decker-shaped silsesquioxane (DDSQ) is a new family of silsesquioxane consisting of nanometer-sized Si-O-Si cage structure functionalized with a wide variety of organic groups. DDSQ-based hybrid polymer (Double-decker-shaped polysilsesquioxane, DDPSQ) possesses many fascinating properties such as high thermal stability, good mechanical properties, low dielectric constant, excellent transparency, excellent flexibility and so on. Due to these fascinating properties, DDPSQ can be used as a potential candidate substrate for various flexible electronic devices. For such applications drawing of conductive metal (Au, Cu, Ag) patterns on a DDPSQ substrate is required. Herein, we have described fabrication of Ag microwiring with submicron resolution on a DDPSQ film by laser direct writing. The line width of the Ag-wiring fabricated by this laser direct-write maskless technique can be controlled flexibly by changing the objective lens magnification and the focusing point. With an objective lens magnification 100x, Ag microwiring with a line width of about 5 μm has been achieved. The Ag-wiring shows an excellent adhesion to DDPSQ surface as evaluated by Schotch tape test. The resistivity of the Ag-wiring is determined to be 4.3 × 10-6 Ω cm ,which is comparable that of bulk Ag (1.6 × 10-6 Ω cm).
Diamond: A New Research Programme to Support UK Decommissioning, Immobilisation and Management of Nuclear Wastes for Disposal
Authors: Hyatt Neil Christian , Biggs Simon R , Livens Francis R. , Young James C.
Published: February 2009

The background and planned research activities are outlined for a new UK research consortium focused on Decommissioning, Immobilisation And Management Of Nuclear-wastes for Disposal (DIAMOND). This consortium is the first integrated trans-disciplinary and multi-institution academic research network in the UK, focused on nuclear waste management.
Glass Development for Vitrification of Wet Intermediate Level Waste (WILW) from Decommissionning of the Hinkley Point ‘A’ Site
Authors: Bingham Paul A , Hyatt Neil C , Hand Russell J , Wilding Christopher R
Published: February 2009

The Immobilisation Science Laboratory, University of Sheffield, is working with Magnox South Ltd to develop a range of glass formulations that are suitable for vitrification of the Wet Intermediate Level Waste (WILW) envelope arising from decommissioning of the Hinkley Point ‘A’ (HPA) power station. Four waste mixtures or permutations are under consideration for volume reduction and immobilisation by vitrification. The inorganic fractions of several of the wastes are suitable for vitrification as they largely consist of SiO2, MgO, Fe2O3, Na2O, Al2O3 and CaO. However, difficulties may arise from the high organic and sulphurous contents of certain waste streams, particularly spent ion exchange (IEX) resins. IEX resin wastes may be the key factor in limiting waste loading, and possible thermal pretreatments of IEX resin to decrease C and S contents prior to vitrification have been investigated. Our results suggest that lowtemperature (90 °C) pretreatment is more favourable than hightemperature (250, 450, 1000 °C) pretreatment. A thorough desktop study has provided initial candidate glass compositions which have been downselected on the basis of glass forming ability, melting temperature, viscosity, liquidus temperature, chemical durability and potential sulphate capacity. Early results for two of the candidate glass formulations indicate that formation of an amorphous product with at least 35 wt % (dry waste) loading is achievable for HPA IEX resin wastes.