bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Application Rate on Droplet Size Spectra and Deposit Characteristics of Dimilin® Spray Mixtures in an Aerial Spray Trial
Authors: Sundaram A , Retnakaran A , Raske AG , West RJ 
Published: December 2008

The wettable powder formulation of diflubenzuron, Dimilin® WP-25, was aerially sprayed as an aqueous suspension over four 15 ha plots in conifer forests in Newfoundland using different volume and emission rates of application. A Piper Pawnee aircraft equipped with six Micronair® AU5000 atomizers delivered the spray mixtures. Plot P9-35/4.7 was treated with 35 g active ingredient (AI) in 4.7 L/ha, plots P10-70/4.7 and P16-70/4.7 with 70 g AI in 4.7 L/ha, and plot P11-30/2.0 with 30 g AI in 2.0 L/ha. The first three plots were each sprayed at an emission rate of 48.13 L/min, the fourth plot at 20.48 L/min. Spray droplets were sampled with Kromekote® cards to determine the size spectra of the spray cloud reaching the ground level. The use of a tracer dye, Erio Acid Red, facilitated droplet measurements on the sampling cards. Glass plates were used to collect deposits of the tracer dye for colorimetric determination of the percent recovery of the spray volume emitted.
The higher emission rate of 48.13 L/min used in plots P9-35/4.7, P10-70/4.7, and P16-70/4.7 resulted in large droplets, higher droplets/cm2, and greater recovery of the applied spray volume at ground level. The lower emission rate of 20.48 L/min used in plot P11-30/20 to accommodate the lower application rate resulted in smaller droplets, lower droplets/cm2, and a smaller percent recovery of the spray volume on glass plates. The smaller droplets have a tendency to linger longer near the forest tree canopy, increasing the chance of impaction on the conifer needles. The lower application rate might provide a better target coverage at canopy level, with minimum ground contamination, and warrants further field testing. The relationship between rate of application and deposit characteristics of Dimilin WP-25 is discussed.
Production of Granular Products by Roll Compaction
Authors: Johnson CE 
Published: December 2008

Particle size enlargement of powders has become a very important process variable. A number of physical properties of powders can be altered to meet specific needs by changing particle size and bulk density.
Roll compaction is a method of agglomeration which offers some unique advantages: 1. High volume production of granules from 0.2 to 6 mm in size. 2. Controls bulk density and flow properties within the limits of the material. 3. Low consumption of energy. 4. Minimum labor requirements.
This paper discusses evaluation of powders and the elements of compacting machine designs.
Reaction Mechanisms and Rate Limitations in Dry Etching of Silicon Dioxide with Anhydrous Hydrogen Fluoride
Authors: Clements LD , Busse JE , Mehta J 
Published: December 2008

A novel dry etching process for silicon dioxide has been developed. This process, carried out at ambient temperature and pressure, uses anhydrous hydrogen fluoride, water vapor in a nitrogen carrier, and a unique processing sequence to achieve etch rates of about 200A/second, with 5 percent or better uniformity.
The overall reaction is a complicated sequence of surface hydration and surface fluorination by adsorption, reaction, and product desorption. This paper presents two proposed reaction mechanisms and describes how experimental data from a laminar flow reactor were used to evaluate the mechanisms.
Process - Induced Influence on the Minority — Carrier Lifetime in Power Devices
Authors: Khanna VK , Thakur DK , Jasuja KL , Khokle WS 
Published: December 2008

Carrier lifetime has been studied as a function of process conditions for power semiconductor devices. The lifetime measurements have been done to see the influence of minority-carrier lifetime on device characteristics under different process conditions such as KOH etching, DI water rinse, deep diffusions, thermal oxidation, phosphorous diffusion and gold diffusion. Open Circuit Voltage Decay (OCVD) and Surface Photovoltage (SPV) techniques have been used to measure minority-carrier lifetime.
It has been observed that the starting-wafer lifetime tends to change strongly during the course of fabrication processes and shows a dependence on the injection level. The typical curves show two-fold effects : (i) The effect of traps and (ii) The carrier density. The injection-level dependence of lifetime is attributed to heavy-doping effects in silicon, and in the absence of traps, is described by an empirical relationship.
Optimum Polysilicon Deposition on Wafer Backs for Gettering Purposes
Authors: Borionetti G , Domenici M , Ferrero G 
Published: December 2008

Polysilicon deposition process parameters have been addressed for the preparation of poly layers having characteristics that increase extrinsic gettering behaviour, irrespective of oxygen enhanced precipitation, thus making them particularly suitable for relatively high device processing temperatures.
Morphological parameters that correlate with extrinsic gettering efficiency have been found to be grain sizes and their preferred orientation, so care was given to produce and consistently reproduce such characteristics by a suitable choice of the deposition process parameters.
Long-Term Corrosion and Deuterium Uptake in CANDU-PHW Pressure Tubes
Authors: Urbanic VF , Cox B , Field GJ 
Published: December 2008

Recent examinations of cold-worked Zircaloy-2 and cold-worked Zr-2.5Nb pressure tubes from CANDU-PHW reactors have extended the corrosion and deuteriding data for these materials up to 5600 effective full power days (efpd), the longest published exposure for these materials in reactor. The examinations have demonstrated that short-term tests to investigate irradiation and water chemistry effects must be supplemented by extended exposures in order to better understand the long-term corrosion and deuteriding behavior of zirconium alloy components with thick oxide films.
In-reactor corrosion and deuteriding of Zircaloy-2 was found to accelerate with time once the oxides exceeded a critical thickness of 15 to 20 µm. Radiolysis within these thick porous oxides, leading to a highly localized water chemistry near the metal-oxide interface, independent of the bulk water chemistry, is suggested as the probable explanation for the acceleration in kinetics. In conformance with this hypothesis, Zircaloy-2 pressure tubes developed large maxima in oxide thickness and deuterium concentration towards the outlet end where the combined effect of neutron flux and temperature was most severe.
Corrosion of Zr-2.5Nb tubes with a similar operating history was about one third that for Zircaloy-2, with no evidence of accelerating kinetics under normal operating conditions. Deuterium uptake was remarkably low, being 2 to 4% of that measured for Zircaloy-2. After 3500 efpd irradiation, the average deuteriding rate in Zr-2.5Nb tubes was only 1.5 mg/kg per year.
The observations are discussed in terms of the current understanding of corrosion and deuteriding processes.
Development of a Sensitive and Reproducible Steam Test for Zircaloy Nodular Corrosion
Authors: Cheng B , Levin HA , Adamson RB , Marlowe MO , Monroe VL 
Published: December 2008

The sensitivity and reproducibility of high-temperature, high-pressure steam tests for Zircaloy nodular corrosion were studied as a function of test parameters, such as temperature, pressure, test duration, and flow rate, using a recirculating autoclave loop. Other variables, such as heat-up rate and oxygen and hydrogen gas contents, were also studied.
The effects of the test variables and gaseous species on test reproducibility are minimized by the addition of a prefilming step at 410°C for 4 to 8 h before exposing the test samples to a higher nodule-forming temperature. The prefilming treatment reduces the degree of nodular corrosion, but the reduced nodule sensitivity can be regained by controlling the second-step test temperature. A test involving a prefilming step at 410°C/1500 psig (102 bars) for 8 h and a nodule sensitivity step at 510°C/1500 psig (102 bars) for 16 h has been found to be capable of reproducibly discriminating Zircaloy cladding source materials into a broad spectrum of nodular corrosion susceptibility. Good reproducibility of the 410/510°C two-step test was demonstrated over 40 test runs using control samples. The two-step test was calibrated to in-reactor corrosion performance using pretested samples and irradiated plenum samples removed from fuel rods.
Mechanistic Studies of Zircaloy Nodular Corrosion
Authors: Cheng B , Adamson RB 
Published: December 2008

The effects of alloy chemistry and thermal processing on corrosion performance of Zircaloy are shown to provide significant insights into the mechanisms governing nodular corrosion formation. Nucleation and growth behavior of nodular oxide in ex-reactor and in-reactor tests were studied phenomenologically, with the results suggesting that the behavior is similar in both environments. The sites of nodular oxide nucleation were found not to be at large precipitates or grain boundaries; rather, the sites were identified, though not unambiguously, to be free of precipitates.
Zircaloy-2 and Zircaloy-4 show significant differences in response to heat treatment in the high alpha phase region; only Zircaloy-2 shows improvement in nodular corrosion resistance. Both alloys, however, become highly resistant to nodular corrosion after receiving heat treatment in the alpha-beta or beta phase fields at temperatures above 830°C. Both the high alpha annealing improvement of Zircaloy-2 and alpha-beta or beta annealing improvement of Zircaloy-2 and -4 are attributed to a redistribution of solute elements into the Zircaloy matrix.
A nodular corrosion mechanism based on local solute depletion and its effects on the stoichiometric structure of the initial black oxide is proposed.
Influence of the Initial Material Condition on the Deformation Behavior of Zircaloy Cladding Tubes in the High-α-Phase Region
Authors: Ortlieb E , Cheliotis G , Weidinger HG 
Published: December 2008

The influence of the initial material condition on the deformation behavior of Zircaloy cladding tubes at 600 and 800°C is systematically investigated by closed end creep rupture tests and transient burst tests in air. At 800°C the strain rate of the cladding tube diameter can be described by the Norton creep equation ˙ε = Aσn exp(− Q/RT) with a constant structure parameter A, stress exponent n, and activity energy Q. The structure parameter A depends on the normalized initial stress σ0/G(T) (σ0 = initial stress; G(T) = temperature-dependent shear modulus) and the initial material condition of the cladding characterized by the yield stress at 400°C and the degree of cold work during the final rocking step.
At 600°C nonstationary creep behavior is reported for the as-cold-worked and partly recrystallized material condition. The Norton creep equation can be maintained with the same constants n and Q if a time-dependent structure parameter is assumed. As a result, the structure parameter A(t) can be written as a function of (1) the “extended normalized annealing time” K(ϕ, t, T), which describes the influence of cold work ϕ, annealing time t, and temperature T on the degree of recrystallization, and (2) the creep deformation represented by the normalized true tangential stress σ(t)/G(T) of the cladding tube sample: 1A(t)−AminAmax−A(t)=a[σ(t)G(T)K(ϕ,t,T)]b where Amin, Amax = empirical minimum and maximum values of A, respectively, and a, b = empirical constants, depending on the degree of cold work.
The analytical treatment is extended to temperature transient processes by using in Eq 1 an effective temperature instead of the actual temperature. The empirical equation (1) together with the Norton creep equation enable the description of the strain rate history of a Zircaloy cladding tube in the temperature range between 600 and 800°C and the dependency on the initial material condition.
Cyclic Behavior of Zircaloy-4 at Elevated Temperatures
Authors: Armas AF , Alvarez-Armas I 
Published: December 2008

The object of the present work is to study the load and strain cyclic behavior of Zircaloy-4 in the temperature range 573 to 873 K. Load cyclic tests are performed at 673 and 873 K for different values of R = σmin/σmax, keeping σmax and the load rate constant at each temperature. At 873 K the lifetime and the cyclic creep rate show a time-dependent behavior, with the mean strain being activated by the mean stress. For zero values of the mean stress (R = −1) no appreciable net strain accumulation occurs and failure by fatigue precedes failure by cyclic creep. At 673 K the mean strain is activated by the mean stress only in the range 1 &gt; R &gt; 0. In the 0 &gt; R &gt; −1 range the cyclic creep becomes faster on decreasing the mean stress up to some R value between −0.9 and −1. This effect is consistent with a dislocation model where the substructure formed in tension is unstable when the loading direction is reversed.
Strain-controlled cyclic tests with a total strain rate of 0.01 and a strain rate of 2 × 10−3s −1 are also carried out in the range 573 to 873 K. The peak tensile stress response during strain cycling shows a cyclic hardening behavior in the range 623 to 823 K. In the region 673 to 743 K this effect is more prominent and the hysteresis loops are nearly independent of temperature and strain rate. This phenomenon and the well-defined cell structure observed by transmission electron microscopy are attributed to strain aging. Below and above this temperature region (at 573 and 873 K) the total stress range remains approximately the same after a few cycles up to near fracture. The dislocation structures observed at both temperatures are consistent with the lack of cyclic hardening or softening.
Interdependence of Chemical and Instrumental Methods of Analysis
Authors: Kallmann S 
Published: December 2008

Chemical methods of analysis are inherently more precise than purely instrumental methods. With the exception of trace metal determinations chemical methods are also more accurate than instrumental methods and have a wider range of application, since final measurements are absolute and do not depend on the availability of standards. The main disadvantage of the classical chemical approach is the length of time required to carry out the analysis.
It will be shown in this paper that chemical methods of analysis can be greatly simplified, and their application range enhanced by incorporating into the procedure various instrumental features. The instrument allows the analytical chemist to (1) examine filtrates for solubility products, (2) avoid reprecipitations by determining specific contaminants by instrumental means, and (3) act as final measuring device, after removing matrix elements by selective or specific separations such as ion exchange, solvent extraction, and precipitations. While the interdependence of chemical and instrumental methods is demonstrated in this paper to be particularly striking in the case of precious metal analysis, an area the author has been concentrating on during the last 15 years, examples of the applicability of the “interdependence” theme to base metal analysis are also provided.
Increase in the Optical Damage Threshold of Cellulose Acetate
Authors: Acharekar MA 
Published: December 2008

Passive Q-switches manufactured with cellulose acetate are generally used in portable/handheld Nd:YAG laser rangefinders. The advantages of this type of Q-switch device are small size, economy and simplicity of operation. However, the limitation of this type of passive Q-switch is its low damage threshold.
For Nd:YAG laser, Bis (4-Dimethyaminodithiobenzil) Nickel dye is generally doped in 0.125 to 0.250 mm thick sheets of cellulose acetate material. Bis-Nickel dye in a cellulose acetate host, when inserted in a Nd:YAG laser resonator and exposed to 1.06 micron radiation, saturates and bleaches giving a giant Q-switch pulse.[1] Commercially available[2] cellulose acetate sheets of this passive Q-switch suffer permanent optical damage when operated at 20 mJ output energy in a 20 ns pulse width at 10 Hz repetition rate. To improve the damage threshold of the passive Q-switch, a process for improving transmission and optical properties (voids, inclusions, etc.) of the host cellulose acetate was developed. The details of the process will be discussed and the damage measurement data collected will be presented.
“A Comprehensive Analytical Theory for Unifying Pulsed and Continuous Wave Laser Damage on Metal Mirrors, Encompassing the Relationship of Small Spot to Large Spot Size Damage on Metal Mirrors.”
Authors: Palmer JR 
Published: December 2008

A theoretical model has been developed which provides for evaluating both pulse and continuous wave laser damage on metal mirrors. The model technique employs the three-dimensional Palmer-Bannett model as a base. Using the fullwidth, half-band temporal profile for the pulse time constant and the thermal diffusivity of copper as a baseline, the time constant is corrected for other materials by the ratio of thermal diffusivities.
Basically, the theoretical concept rests on the premise that neither the Drude theory nor the Jakob-Kelvin theory are completely correct for short-pulsed (i.e., less than a microsecond) time constants. The heat sink below the first few angstroms acts as a dampening coefficient. The metal does not appear to be able to respond to the very short time constants and, as a consequence, the temperature versus reflectivity does not hold in straight-forward fashion. As the time constants extend into the microsecond regime, and longer, the relationships of temperature versus reflectivity become more representative.
Melt and Slip thresholds for copper, silver and gold have been presented previously [1]. The data have been generated for wavelengths of 1.06 μm, 2.7 μm, 3.8 μm, and 10.6 μm. Varying spot-sizes and different pulse widths were used. The theoretical model has been applied against this datum with excellent results ranging from 99.8% to 82% agreement.
Based on the relationship suggested by the three-dimensional Palmer-Bennett model and the unifying theory suggested, spot size dependence may be determined for given metal diamond turned mirror substrates.
The basis for damage, selected for the theory, is the point where slip phenomena occurs in the metal surface. This selection is more than arbitrary. Slip phenomena becomes the first indication that there is a permanent disruption to the optical surface. Further, slip and melt would seem to be the most thermally dependent manifestations of disruption.
A Proposed Cooperative Program on Statistical Ecology and Environmental Statistics for Increased Resource Productivity and Environmental Protection and the Panel Discussion at the ASTM Symposium on Statistics in the Environmental Sciences
Authors: Patil GP 
Published: December 2008

The ASTM Symposium on Statistics in Environmental Sciences appeared to be an appropriate forum for an effective dialogue for agencies, industries, and academia to do something together that should be timely, fruitful, and synergistic. A panel discussion on a much needed cooperative program on statistical ecology and environmental statistics for increased resource productivity and environmental protection was organized for the morning of the second day of the symposium program. The present article is especially prepared to report on the session with multifaceted discussion for the benefit of the wider readership.
The proposed cooperative program considers formulation of prototype and experimental programs, such as, cooperative centers for statistical ecology and environmental statistics to conduct collaborative research on contemporary quantitative studies and issues in statistical ecology and environmental statistics involving scientific and public policy research. The proposed cooperative program also needs to formulate mechanisms for effective communication and continuing dialogue, such as, a quarterly scientific newsletter, timely symposia and workshops, satellite courses, and conferences with emphasis on contemporary quantitative studies and issues in statistical ecology and environmental statistics.
Overview of the National Discharge Monitoring Report (DMR) Quality Assurance (QA) Program
Authors: Polvi GR , To YS , Lim EC 
Published: December 2008

As mandated by the Clean Water Act, wastewater treatment facilities are regulated under the National Pollutant Discharge Elimination System (NPDES). Direct discharges have unique NPDES permit with discharge limits and a self-monitoring requirement. The effectiveness of the NPDES Program hinges on the quality of the self-monitoring data.
The DMR QA Program evaluates the date quality from the NPDES permittees. Since 1978, the Program has helped to assure the data quality of DMRs. Under this Program, all major permittees are annually sent performance samples, to be analyzed and reported the same way as required in the permits. The results of these permittee tests are compared with an established range of acceptance for each test parameter by EPA to identify potential problems with analytical or reporting procedures. EPA/State then follow-up through correspondence or on-site visits with permittees to resolve the problems.
As an overview, the history, authority, procedures, use of data, and implementation issues are reviewed.
Quality Assurance for Human Exposure Studies
Authors: Hackworth LT , Jordan RC , Smith DH , Howard JN 
Published: December 2008

Data derived from exposure of human subjects to air pollutants are a basis for setting air quality standards. It is therefore imperative that those data be valid and defensible.
Since 1979, Northrop Services, Inc.-Environmental Sciences, under contract to the U.S. Environmental Protection Agency, has been responsible for the development and implementation of a comprehensive program of quality assurance for human exposure studies. Exposure studies are conducted in controlled environment laboratories located in Chapel Hill, North Carolina.
The planning and design of the quality assurance (QA) program are discussed. Details of the conduct and scheduling of systems and performance auditing, as well as hardware and software needs, are provided. A historical review of auditing results is presented, and unique problems are described for pollutant generation, delivery, and control systems as well as environmental control and physiological data acquisition.
Reference Samples for Water-Related Programs in the U.S. Environmental Protection Agency
Authors: Winter JA 
Published: December 2008

The Environmental Monitoring and Support Laboratory at Cincinnati provides quality assurance (QA) support for U.S. Environmental Protection Agency (EPA) water-related programs in response to the Clean Water Act (P.L. 92-500), the Safe Drinking Water Act (P.L. 93-523), the Marine Protection, Research, and Sanctuaries Act (P.L. 92-532), the Resources Conservation and Recovery Act (P.L. 94-580), the Comprehensive Environmental Response and Liability Act (P.L. 96-510), and the Toxic Substance Control Act (P.L. 94-469), and their amendments.
Two important segments of this support are the Quality Control Sample Program, which furnishes samples of known concentrations for use as independent checks on intralaboratory QA activities, and the EPA's Repository for Toxic and Hazardous Materials, which provides calibration standards and spiking solutions for trace organic analyses of interest to the Agency. Each series contains one or more analytes, with true or reference values. The samples and standards are prepared as stable concentrated solutions in all-glass ampuls for dilution to volume, and analyses by EPA, its contractors and grantees, and other federal, state, and local agencies.