bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selecting the Ideal Preservative for Aqueous Pesticide Formulations
Authors: Chasin DG 
Published: December 2008

With few exceptions, pesticides formulated as aqueous solutions and suspensions (flowables) require a preservative. Even most fungicide aqueous flowables require an effective bactericide. Preservatives are primarily incorporated to prevent (1) deterioration of sensitive formulation components (eg. rheological modifiers), and (2) formation of microbial slimes which can clog spray nozzles. The many requirements imposed on preservatives include (1) broad spectrum antimicrobial activity, (2) non-reactivity with other formulation components, (3) low phytotoxicity and mammalian toxicity, (4) activity over wide pH range, (5) high temperature stability, (6) ease of assay, (7) environmental safety, and (8) broad regulatory approvals. Considerable testing is required to determine the most cost-effective preservative level in each formulation.
Covered in this paper are (1) sources and control of contaminating organisms, (2) the importance of test organism adaptation and “challenge” testing in determining microbial susceptibility and optimal preservative level, and (3) comparison of several preservatives — including formaldehyde and 1,2-benzisothiazolin-3-one (active ingredient in PROXEL® GXL) — covered by EPA regulation 40 CFR 180.1001.
Using the Predictive Powers of Triangular Co-Ordinate Plots for Designing Agricultural Formulations
Authors: Botts MF 
Published: December 2008

An agricultural formulation candidate was developed with the aid of triangular co-ordinate plots. It was found that when a candidate formulation must satisfy many requirements, a plot is useful for managing the large number of variables involved.
A plot was produced which showed how emulsion stability varies with formula composition. Each point in the plot was shown to carry a large amount of information. The point describes the complete composition of the recipe it represents and by its coding it also describes the emulsion stability of the recipe.
From the coding of the first group of points produced for the plot, it was possible to predict what composition regions would most likely produce the best emulsion stability. Subsequent groups of points were added to more closely define the boundaries of the best emulsion stability region.
The preparation of triangular co-ordinate plots show promise for automation. Data for one example given were obtained by laboratory robotics. This capability makes the design of formulations with the aid of triangular co-ordinate plots quite attractive, because the numerous points required can be obtained with a laboratory robotic arm [1].
Plant and Mineral Oils as Insecticide Adjuvants: Effects on Residues and Toxicity
Authors: Plapp FW 
Published: December 2008

Effects were measured of combining plant and mineral oils with insecticides on residue properties of insecticides on cotton leaves. Surface residues of a relatively polar organophosphate, parathion, were increased in persistence. Little effect of oils on residue properties was found in tests with the more nonpolar synthetic pyrethroid, permethrin.
Effects of oils on insecticide toxicity were measured in tests where insects were exposed to residues on glass surfaces. All oils increased efficacy of organophosphate and pyrethroid insecticides.
Thus, oils are effective in modifying both insecticide residue life and toxicity. Polarity us test insecticides and nature of the oil are important variables in determining the effects produced.
Progress in the Knowledge of Nodular Corrosion
Authors: Garzarolli F , Stehle H , Steinberg E , Weidinger H 
Published: December 2008

Zircaloy in boiling water reactor (BWR) systems often exhibits, besides slight uniform corrosion, a nodular type of corrosion. Highest nodular corrosion was found with materials never β-quenched during their fabrication, whereas β-quenched materials generally showed an improved behavior. Results of nodule thickness measurements after increasing burnup were normalized by using a correlation w ∼ (BU)0.7 (w = average nodule oxide thickness, BU = burnup). The scatterband of the normalized data was different for different reactors. The statistical distribution was generally Gaussian with a tail at high values.
To find reasons for the material-inherent scatter of the in-pile corrosion behavior, archive samples were examined by electron microscopy and high-pressure steam tests. The latter led to a comparable ranking if the specimens were fully recrystallized before testing. The microstructural examinations indicate a correlation of the in-pile corrosion with the size distribution of the intermetallic precipitates and the spacing between the precipitates.
High-pressure steam tests have been used to identify the fabrication steps which influence nodular corrosion. According to these tests it is mainly the β-quenching treatment and all annealing or working steps in the upper α-phase range that have an influence.
Low nodular corrosion was achieved using quenching rates &gt;5 K/s if the subsequent annealing stays in the low α-range. In the cold-worked condition, nodular corrosion in general was less pronounced. However, with respect to the in-reactor performance, no marked difference was found between stress-relieved and fully recrystallized cladding tubes.
For actual practice it is concluded that an appropriate β-treatment is needed and that temperature treatments of the material after its last β-quenching should stay within a range in which the distribution of the alloying elements is not affected unduly. Several in-pile programs are under way in cooperation with utilities to confirm the progress achieved.
Recent Studies of Crack Initiation During Stress Corrosion Cracking of Zirconium Alloys
Authors: Cox B , Haddad R 
Published: December 2008

In order to study crack initiation, we had first to develop a technique for reproducibly obtaining large numbers of very small crack initiation regions. The previously used test methods of stressed split-rings or pressurized (or compressed) tubes gave low success rates. Specimens either showed through-wall cracks, or no cracks, with few incipient cracks being observed. This suggested that the propagation time was short compared with the incubation time. Attempts to overcome this by unloading specimens following the first acoustic emission signal still gave a low frequency of incipient cracks.
The possibility that an “active path” mechanism was the cause of the difficulties in obtaining incipient cracks reproducibly was investigated by a stress-pulse technique. The results were apparently consistent with an “active path” developing ahead of the crack tip, and cracking during the stress-pulse. Two iodine tracer techniques, one using radioactive 131I, the other using natural 127I (located by Rutherford backscattering), showed that iodine did not diffuse ahead of the crack tip. When specimens were not statically loaded, but merely given a stress-pulse, the results showed that the appearance of an “active path” mechanism resulted from the length of time taken for the chemistry inside the apparatus to reach a condition capable of initiating cracking. When the system was allowed to come to chemical and thermal equilibrium before the specimen was loaded, cracking started almost immediately (&lt;2 min). This virtual disappearance of the incubation time with adequate equilibration of the apparatus was equally true for experiments in I2 or Cs/Cd vapours. It was concluded that, if the chemistry of the system could be rapidly equilibrated, there would probably be effectively no incubation time and cracking would start immediately.
Many small incubation sites were produced in these tests. No second-phase particles were seen at these sites in the SEM, and no local contamination of the initiation site was seen by energy dispersive X-ray analysis (EDAX). The initiation sites were individual grains (or small groups of grains) which fractured transgranularly to give a fractography otherwise identical with transgranular fracture surface produced during crack propagation in the bulk of the specimen. It was concluded that localized residual stresses, when added to the applied load, cause a few correctly oriented grains at the surface to crack immediately upon loading, given that the “correct chemistry” was present.
The presence of organic-iodine compounds (in particular methyl iodide) as impurities in the vapor phase was found to act as a promoter of crack initiation, giving a large increase in the frequency of initiation sites and an increase in crack velocity. Methyl iodide also gave a characteristic fractography which was explained as a modification of the propagation mode of the crack front.
The U.K. Approach to Dust Explosibility Assessment and Its Relevance to Explosion Prevention and Protection
Authors: Abrahamsen AR 
Published: December 2008

Dust explosibility assessment in the United Kingdom is in a transitory period as traditional test methods based on the Hartmann apparatus become superceded by methods in line with European codes of practice.
The minimum explosible concentration is measured in the open Hartmann tube using a test method with severe drawbacks. Recent years have seen the use of a 15-L apparatus and the 20-L sphere as means of generating a dust cloud more representative of the industrial scale. The sensitivity to ignition of a dust cloud in relation to electrostatic hazards is represented by its minimum ignition energy. The corresponding test method is the subject of controversy in terms of the spark generating mechanism and various methods may be adopted to simulate a typical “industrial” spark.
Minimum ignition temperatures of dust clouds are measured in the Godbert-Greenwald furnace. However, this apparatus has the disadvantage of not having an independent ignition source to enable minimum explosible concentration or ignition energy measurements to be made at elevated temperatures. A 1.2-L furnace based on a U.S. Bureau of Mines design partly overcomes this problem.
The determination of explosion pressures and rates of pressure rise is essential for the optimum design of explosion protection systems. Methods for measuring these parameters have undergone radical change in recent years, and although the Hartmann bomb apparatus is still accepted in U.K. industry, its use nowadays is not recommended, the 1-m3 or 20-L sphere vessels being preferred.
The lack of a dedicated British Standard on dust explosibility testing is one of the reasons for the apparently confused attitude towards the subject which exists in many parts of industry. The use of a vessel, such as the 20-L sphere, to measure all dust explosibility parameters (except minimum ignition temperature) is strongly advocated to give data which can be reliably applied to full-scale situations, something which the small Hartmann tube cannot be expected to give.
Recent Dust Explosion Experiences in the U.S. Grain Industry
Authors: Kauffman CW 
Published: December 2008

After the explosions of December 1977 intense scrutiny was given to the occurrence of fires and explosions in grain handling and processing facilities in the United States.
The conditions leading to fires and explosions in these facilities—fuel, oxidizer, ignition, mixing, and confinement—had been identified immediately following World War I.
At the beginning of this decade the National Academy of Sciences investigated 14 explosion incidents, reported on the findings, and made recommendations concerning accident prevention. As the decade has progressed, however, these fires and explosions have continued with reports of investigations being available for some major incidents. The continuing critical factor in these explosions is the massive uncontrolled accumulations of fuel. In the effort to eliminate this industrial hazard, the U.S. Department of Labor has issued Draft Final Standards pertaining to safety hazards in grain-handling facilities. It is clear that it is technically feasible to eliminate fire and explosion hazards from the grain and agricultural products industry because these events do not occur as a result of unknown, unpreventable causes.
Quality Assurance in Metals Analysis Using the Inductively Coupled Plasma
Authors: Watters RL 
Published: December 2008

The inductively coupled plasma (ICP) technique is a useful approach for multielement analysis of a wide variety of materials. Published reports have described the successful application of the ICP technique for the analysis of trace, minor, and major elements in metal alloys. When assessing the quality of analytical results using the ICP or any other technique, one must consider the contribution of various parts of the measurement process to the total error. In addition to random error, a careful evaluation of all possible sources of systematic errors must be undertaken, so that the appropriate corrections can be applied to the analytical results. Emission spectroscopists are well aware of the problems caused by spectral interferences in ferrous matrices. The inherent linearity of the ICP technique offers a correction scheme for dealing with spectral interferences, but the method of measuring correction factors and accounting for their variability warrants close examination.
Most descriptions of ICP applications report relative freedom from matrix effects. Although the magnitude of systematic errors may be less than for other spectrometric techniques, such errors can cause analytical bias, which can appreciably affect the final results. For example, it has been shown that differences in acid concentration between pure element standards and the sample can cause systematic error. This type of problem can occur when complex alloys are dissolved for ICP analysis. Examples of these kinds of errors and approaches to correcting for them are presented.
Recent Damage Results on High Reflector Coatings at 355 nm
Authors: Carniglia CK , Hart TT , Rainer F , Staggs MC 
Published: December 2008

Several studies of damage induced by 0.6 ns, 355 nm laser pulses have been carried out on thin-film reflectors. The reflectors consisted of dielectric materials vacuumdeposited onto BK7 substrate by evaporation. Each part was damage tested on several sites using one laser shot per site.
Quarterwave stacks of various material combinations were used to make a series of reflectors. Four to six parts were tested for each of four materials combinations. The average damage thresholds obtained for these coatings were 3.5 J/sq. cm for scandia/magnesium fluoride, 3.0 J/sq. cm for zirconia/silica, 2.4 J/sq. cm for tantala/silica and 1 J/sq. cm for hafnia/silica. Interestingly, there was no improvement in those reflectors to which a halfwave silica overcoat was added. This is contrary to previous results at 1064 nm and 248 nm.
A series of zirconia/silica reflectors was made using coating temperatures ranging from 150°C to 300°C. The thresholds were slightly improved by coating at higher temperatures.
Coatings made of zirconia/silica with outer quarterwave layers of samarium fluoride and either silica or magnesium fluoride were also tested. Thresholds for these coatings ranged from 1.7 to 2.8 J/sq. cm and were slightly lower than the thresholds of the zirconia/silica stacks alone.
Scandia/magnesium fluoride coatings with non-quarterwave designs have been shown to be effective in raising the damage threshold of high reflectors at 248 nm. Such designs reduce the electric field intensity in the outer scandia layers. The damage thresholds of several non-quarterwave designs were compared. The highest threshold, 5.1 J/sq. cm, was achieved by reducing the electric field in the two outer scandia layers.
Photothermal Deflection Microscopy of HR and AR Coatings
Authors: Mundy WC , Ermshar JEL , Hanson PD , Hughes RS 
Published: December 2008

Last year at this syposium we reported on the initial results of photothermal deflection microscopy (PDM) studies of single layer dielectric thin films [1]. The high spatial resolution, low-level absorption capabilities of PDM were demonstrated in the form of two-dimensional absorption contour maps of such films.
In this paper we report on PDM measurements of a number of HR and AR coatings provided by Lawrence Livermore Laboratory and the Naval Weapons Center. The absorption data obtained from these measurements provide the first phase of absorption/damage correlation studies and as these absorption measurements were recently completed, no correlation data are yet available.
Resolution improvements, measurement methodology and a number of absorption contour maps are presented. Two interesting observations yet to be explained are described and some future experiments are suggested.
Stress Distributions in Damaged Composites
Authors: Batdorf SB , Ghaffarian R 
Published: December 2008

Any micromechanical theory for damage accumulation and ultimate failure in composites must depend on a knowledge of the detailed stress distribution in the damaged state. Lack of this knowledge has been a major roadblock to progress in this field. A shear lag approach to this problem has been proposed by Hedgepeth and Van Dyke for unidirectionally reinforced composites, but it is of limited utility because it contains an unknown parameter.
This paper discusses an experimental technique for finding stress distributions in damaged composites with the aid of an electric analogue. In this approach, a current is passed through a model employing conducting rods to represent fibers and a liquid electrolyte to represent the matrix. The potential distribution in the model is analogous to the longitudinal displacement distribution in the composite, and transverse currents are analogous to shear forces. The analogue is employed in the paper to evaluate the unknown parameter in the Hedgepeth and Van Dyke equation.
A Simple Apparatus for Measurement of the Hydration Ratio of Plasters and Plaster Rocks
Authors: Karmazsin E 
Published: December 2008

In the frame of calcium sulfate β-hemihydrate hydration kinetical studies, a simple experimental set up has been developed to determine the rate of hydration for different species of incompletely hydrated plaster specimens. This apparatus may also be used to determine with accuracy the amount of gypsum contained in plaster rocks, and acquire simultaneously quantitative analysis for six specimens. The apparatus is described, and the effect of vapor pressure is studied.
Experimental results on incompletely hydrated plaster specimens show that either the weight loss or the integration curves allow the determination of the hydration ratio of the specimen with high accuracy. It has been experimentally shown that the amount of heat involved in the hydration reaction is proportional all along the reaction to the conversion rate.
Monsanto Analytical Testing Program for NPDES Discharge Self-Monitoring
Authors: Hoogheem TJ , Woods LA 
Published: December 2008

The Monsanto Analytical Testing (MAT) program was devised and implemented in order to provide analytical standards to Monsanto manufacturing plants involved in the self-monitoring of plant discharges as required by National Pollutant Discharge Elimination System (NPDES) permit conditions. Standards are prepared and supplied at concentration levels normally observed at each individual plant. These levels were established by canvassing all Monsanto plants having NPDES permits and by determining which analyses and concentrations were most appropriate. Standards are prepared by Monsanto's Environmental Sciences Center (ESC) using Environmental Protection Agency (EPA) methods. Eleven standards are currently available, each in three concentrations. Standards are issued quarterly in a company internal round-robin program or on a per request basis or both.
Since initiation of the MAT program in 1981, the internal round-robin program has become an integral part of Monsanto's overall Good Laboratory Practices (GLP) program. Overall, results have shown that the company's plant analytical personnel can accurately analyze and report standard test samples. More importantly, such personnel have gained increased confidence in their ability to report accurate values for compounds regulated in their respective plant NPDES permits.
Resistance to Compaction of Asphalt Paving Mixtures and Its Relationship to Stiffness
Authors: Bissada AF 
Published: December 2008

This paper discusses a method of evaluating the compaction characteristics of asphalt concrete mixtures in terms of a coefficient of compactibility or resistance to compaction. Two types of asphalt concrete mixtures have been considered in this study: one is a conventional type with an asphalt cement 60/70 penetration, and the other is an extended sulfur asphalt concrete with 40/60 sulfur to asphalt (S/A) ratio by weight. The effect of mix variables, such as filler content and binder content, is included in the experimental program. Marshall specimens for each mix were subjected to different compaction levels varying between 10 and 100 blows on each face. Bulk density and voids content for each mix at each compaction level were determined. Each specimen was then tested for creep at 40°C under a controlled constant stress (0.1 N/mm2) for 30-min load duration.
Based on the experimental data and using linear regression analysis a relationship between compactibility and stiffness characteristics for each mix is established, which is important in controlling the permanent deformation distresses. The results of this study show that the specifications requirement for a certain percent of laboratory compaction would not be adequate for predicting permanent deformation of the asphalt pavement layer. An additional requirement, such as resistance to compaction, may correlate better with the actual performance of the tested mixture under appropriate conditions of environment and traffic.
Copper Standard Reference Materials (Benchmark Series)
Authors: Barnes IL , Gills TE , Reed WP 
Published: December 2008

The Standard Reference Materials Program has experienced increasing demands for new kinds and types of standard materials. In order that the largest number of users be served by these materials and the available resources be used to best advantage, careful planning is required. The planning process helps to ensure that, among other factors, the fewest number of different materials will be produced, a wide range of needs will be met, and production and certification can be accomplished at a level consistent with the intended uses. One output of this process has been the concept of “Benchmark Series” SRMs. These are usually a set of similar materials with varying amounts of a number of elements covering a wide range of concentrations.
Largely through the auspices of ASTM Committee E-2 on Emission Spectroscopy, more than 70 persons from NBS, ASTM, and from throughout the copper industry contributed to the planning of a series of Copper Benchmark Standard Reference Materials. As a result, 12 different materials issued as chips, rods, and cast solids and representing as many as 25 different SRMs have been prepared and certified for as many as 29 elements. The production and certification process and the certified values for this important series are described and the certified values are given.
Analysis and Growth of Cracks in Skins with Variable Thickness
Authors: Ratwani MM , Kan HP 
Published: December 2008

Analysis of cracks in skins with variable thickness (skins with lands) was developed. The problem was reduced to the solution of an integral equation by using the Fourier transform technique. The integral equation was solved numerically and stress intensity factors were obtained. The influence of variable skin thickness ratios on stress intensity factors was investigated.
An experimental program was carried out to obtain crack growth data in skins with variable thickness (skins with lands). The crack growth behavior in those skins was predicted using analytical stress intensity factors and a crack growth model. A good correlation between predicted and observed crack growth behavior under constant amplitude as well as spectrum loading was found.