bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparisons of Drift Reducing/Deposition Aid Tank Mixes for Fixed Wing Aerial Applications
Authors: Wolf RE , Gardisser DR , Loughin TM
Published: August 2005

A field study was conducted to determine the influence of adding spray drift control/deposition aid products to tank mix solutions for fixed wign aerial applications. Downwind horizontal drift, vertical drift, and droplet spectra characteristics in a canopy top were collected on water sensitive paper (WSP) for measurement and analysis. Spread factors for each spray mix sample were determined and were used as part of the analysis procedure with the canopy measurements. DropletScan™ was used to analyze the WSP. Percent area coverage for the horizontal and vertical drift profiles was used as a means to separate differences in treatments. DropletScan™ with adjusted spread factor coefficients was used to calculate Dv.1, Dv.5, and Dv.9 at the canopy top for each treatment. Differences in products at all horizontal and vertical collector positions were measured. When compared to water, results show that some of the products did not provide any benefits for drift reduction and, in fact, may have increased the drift potential. A few of the products exhibited the potential to reduce the amount of drift. Droplet sizes for Dv.1, Dv.5, and Dv.9 increased with the addition of the drift control/deposition aid products into the tank mix. The increases were variable across products and aircraft.
Dearomatized Fluids Used in Phenoxy Herbicides for Right-of-Way Sprays
Authors: Krevalis MA
Published: August 2005

Middle distillates, such as kerosene or diesel, are often used as carriers and adjuvants in phenoxy herbicides for turf, right-of-way sprays, and other applications. In recent years, however, the use of middle distillates in these applications has come under pressure due to toxicity concerns. As an alternative to these middle distillates, it has been proposed that dearomatized fluids could be used in these applications, potentially giving better performance. The lower volatility and lower phytotoxicity of the dearomatized fluid may promote enhanced uptake of the herbicide, resulting in improved performance. To test this proposal, a study was conducted comparing the use of dearomatized hydrocarbon fluids (such as Exxsol® D110 fluid) as both solvent and adjuvant to the use of kerosene/diesel as the solvent/adjuvant combination in right-of-way sprays. The herbicide product 2,4-D Ester was applied to three vegetation types at two rates, the vegetation types including kochia, marestail, and horsetail. Results from the study showed that the 2,4-D Ester gave good control of marestail and equisetum, but only poor control of kochia. In all cases, the dearomatized fluid performed as well as kerosene/diesel, demonstrating that dearomatized fluids can be used as a safe replacement for middle distillates in these applications.
New Technique for Measuring Extended Viscosity Ranges - Gel Times, Pot Life, or Cure Monitoring - with Programmable Rotational Viscometers or Rheometers
Authors: Moonay DJ
Published: August 2005

A new algorithm written in commercially available software controls programmable viscometers and rheometers so that multiple decades of apparent viscosity data may be acquired. This work is new and important because previous methods involved either: (1) very simple instrumentation providing (a) single-point viscosity data or (b) equipment providing “gel times” but no viscosity data, or (2) complicated instrumentation costing at least $20 000. Isothermal cure of a common epoxy system was successfully monitored in this work. Apparent viscosities measured during one room-temperature cure experiment ranged from approximately 1000 mPa·s to 50 000 000 mPa·s. Good repeatability of data was found for different batches prepared with similar stoichiometry. Viscosities measured at approximately 167 min of cure time, during multiple tests, differed by less than 1 %. Various test geometries were used, including disposable cylindrical spindles and sample chambers, to allow easy cleanup, with samples 10 mL or less in size. Samples were also successfully tested at 50 and 60°C. Aspects of the algorithm and its implementation are discussed. It is hoped that this new method will help personnel testing adhesives.
Elemental Analysis of Lubricating Grease by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
Authors: Fox BS
Published: August 2005

Lubricating grease is a mixture with complex properties that poses far more difficult analytical challenges than do its individual components. At many petroleum testing laboratories, Inductively Coupled Plasma Atomic Emission Spectroscopy, or ICP-AES, is used for the analysis of additive elements and wear metals in oil. However, it may also be used to measure the concentration of both additive metals and contaminants in lubricating grease. However, unlike some of the other matrices that are routinely analyzed, grease cannot be simply diluted for direct sample introduction into the instrument without some form of acid digestion. This paper will discuss how ICP-AES is used as a grease analysis tool. Several sample preparation schemes will be covered, including classical sulfated ash on a hot plate, microwave assisted dry ash, and microwave assisted acid digestion. Comparison data from different digestion techniques will illustrate potential problems that may be encountered by the analyst in each of these methods. The advantages of closed-vessel microwave digestion for the analysis of elements that are often volatilized under normal digestion conditions will be discussed.
The Use of Microwave Digestion and ICP to Determine Elements in Petroleum Samples
Authors: Hwang JD , Horton M , Leong D
Published: August 2005

ICP-AES analyses are prone to erros caused by changes in the power level, nebulization rate, plasma temperature, and sample matrix. This is especially true for ICP-AES and ICP-MS organic applications in the petroleum industry where extremely complicated sample matrices are common. As a result, accurate analyses of petroleum lubricants, lubricant additives, fuels, crude oils, residues, and related materials often require bracketing with matrix matched standards, the use of internal standards, and a flexible ICP-AES/ICP-MS system. Many new innovative analytical instruments were developed to better improve elemental analysis in the last few decades. However, sample preparation remains the formidable challenge because it is always labor-intensive, cumbersome, and does not permit fast operation. It is encouraging to see the application of microwave radiation field as the energy source for sample digestion to pursue more reliable, but simpler, safer, more rapid, and less expensive methods, particularly in the petroleum industry.
Low-Level Sulfur in Fuel Determination Using Monochromatic WD XRF—ASTM D 7039-04
Authors: Chen ZW , Wei F , Radley I , Beumer B
Published: August 2005

A monochromatic wavelength dispersive X-ray fluorescence (MWDXRF) technique has been successfully developed for measuring low-level sulfur in fuel. In this technique, two doubly curved crystal (DCC) optics were used to provide monochromatic excitation and fixed channel wavelength dispersive analysis. Using highly efficient DCC optics, compact bench top MWDXRF analyzers for sulfur analysis have been successfully produced. A new ASTM standard test method for low-level sulfur determination in diesel and gasoline, D7039-04, has been developed based on this technique. Data for ultra-low-sulfur fuel were collected and analyzed using this new method. In this paper, the results of repeatability, reproducibility, and bias are presented and discussed. The repeatability for 10-ppm sulfur fuel was shown to be around 1 ppm. The pooled limit of quantification (PLOQ) for ultra-low-sulfur diesel was found to be less than 1.5 ppm in this study. The reproducibility of 15-ppm sulfur diesel fuel was determined to be better than 3 ppm (95 % confident level). The limit of detection for a single analyzer was found to be 0.36 ppm. The effect of matrix composition was investigated. The correction due to matrix for low-level sulfur diesel and gasoline is generally not significant.
Pyro-Electrochemical On-Line Ultra Low Sulfur Analyzer
Authors: Rhodes JR
Published: August 2005

Current and upcoming regulations worldwide require maximum concentrations of sulfur in fuels to be in the range 10–50 mg/kg. This paper describes a new on-line analyzer for ultra low sulfur, the first to employ “Pyro-electrochemical” technology, which is significantly simpler than other pyrolysis methods such as Pyro-microcoulometry and Pyro-UV fluorescence.

The technology is based on ASTM D 6920. The instrument is described with special reference to the modifications needed to adapt the technique to on-line analysis. Experimental results are given for long term stability, sensitivity, precision, speed and linearity of response, temperature stability, and sensitivity to nitrogen.
Analysis of the Volatiles Generated During the Selby-Noack Test by 31P NMR Spectroscopy
Authors: Bosch RJ , Fee DC , Selby TW
Published: August 2005

A series of engine oil samples collected during a study of their Phosphorus Emission Index values were analyzed by 31P Nuclear Magnetic Resonance Spectroscopy. (The PEI analyses themselves were presented in an associated paper [1]). NMR spectra were generated to obtain and explain the mode of formation and identity of the phosphorus-containing species in the volatiles generated during the Selby-Noack volatility test and to compare these species to those found in both the fresh oil and the residual oil remaining after the volatility test.
Improvements in the Determination of Fluorine in Fuel and Lubricants by Oxidative Combustion and Ion-Selective Electrode Detection
Authors: Nash LJ
Published: August 2005

Oxidative combustion combined with ion-selective electrode detection is one of several techniques available for the analysis of fluorine in fuels and lubricants to the petroleum and petrochemical industry. This technique was first developed in the mid-1990s to provide an alternative to the widely used Wickbold method, which is very time consuming and extremely hazardous. The early designs were marginally successful due to the lack of sensitivity and stability, the use of large volumes of solvents, inconsistent delivery of fluids, plugging of catch and hold valves, numerous sources of contamination, and long analysis times. The design has been refined to enhance the sensitivity, stability, and accuracy of the fluoride determination. Enhancements include improved ion-specific electrodes with increased sensitivity, the use of circulating baths to stabilize temperature fluctuations, improved sample introduction and flow systems, and redesigned electronic circuitry.
Aging & Environmental Exposure Properties of a Fire Protection Material
Authors: Licht RR
Published: August 2005

Materials designed for passive fire protection, such as putties, caulks, sealants, and devices, have been in commercial use for more than 25 years. These products are used to seal openings in the walls and ceilings of fire-rated spaces to restrict the passage of toxic fumes, smoke, and flames in the event of a fire. Passive fire protection, which is specified in building codes across the U.S., has been shown to be effective in helping to contain fires and reduce property damage, injuries, and loss of life.

This paper will discuss age and compatibility testing of one product used in fire protection of penetration seals and joints. It will also advocate the development of a new standard in ASTM E6.21 subcommittee for environmental exposure and a simple method for aging of penetration fire stop and joint protection materials.
Stress Analysis of Asymmetric Co-Cured Stepped-Lap Joints
Authors: Graham SM , Crane RM
Published: August 2005

Manufacturing of large adhesively-bonded structural joints in the marine composites industry requires careful design and manufacturing to ensure durability of the joint. When the adherends to be joined are both fiber-reinforced laminates, an alternative to adhesive bonding is to co-cure the joint. This process eliminates the adhesive layer and the two interfaces between the adhesive and the adherends. The continuous matrix surrounding the fibers on either side of the joint influences the load transfer and the corresponding stresses developed in the joint. In this study, finite element analysis was used to investigate the stresses developed in a co-cured stepped-lap joint made from adherends with unequal stiffness. Two different approaches were used to model asymmetric joints with uniform step lengths: a homogeneous approach that modeled each adherend as transversely isotropic, and a constituent-level approach that modeled the resin and idealized fibers individually. It was found that the co-cured stepped lap joint behaves very much like a series of adhesively bonded lap joints. The shear stress distribution for step length to ply thickness ratios greater than about 10 exhibits a parabolic shape with peaks at the ends and lower values in the center, which is very similar to the stress distribution in adhesively bonded stepped lap joints. It was observed that the peak and minimum stresses approach a steady value with increasing step length, implying that there may be a limiting strength for an asymmetric co-cured stepped lap joint.
Comparative Evaluations of Surface Characteristics of cp Titanium, Ti-6AI-4V and Ti-15Mo-2.8Nb-0.2Si (Timetal® 21SRx)
Authors: Petersen DW , Lemons JE , Lucas LC
Published: August 2005

Commercially pure titanium (cpTi), Ti-6A1-4V (Ti64), and Ti-15Mo-2.8Nb-0.2Si (21SRx), with three unique atomic, alpha, alpha-beta, and beta grain structures, respectively, were subjected to three different surface treatments: cleaning, nitric acid passivation, and heat treatment. Experiments were conducted to determine the effects of the type of material and surface modifications on the substrate microstructure, surface oxide composition and thickness, and resultant corrosion behavior.

Metallography showed the cpTi groups were an equiaxed single alpha phase material, the Ti64 groups a dual-phase alpha-beta material, and the 21SRx groups an equiaxed beta material. The different surface treatments did not alter the substrate microstructures of any groups.

Spectroscopic (AES) results showed typical titanium and titanium alloy spectra with dominant Ti and O peaks for all sample groups, indicative of titanium dioxide. In addition, small Al and Mo peaks were detected throughout the surface oxides of the Ti64 and 21SRx specimens, respectively. AES depth profiling showed no significant difference in the oxide thickness between all the Cleaned and Passivated groups regardless of metal or alloy group. However, all the Heat Treated groups had significantly thicker oxides.

In general, corrosion results showed Passivated and Heat Treated groups to have similar corrosion properties and significantly improved corrosion resistances compared to the Cleaned groups. All impedance spectra fit into the Randles equivalent circuit model, and all sample groups exhibited near ideal capacitive behavior (φ ≅ 90°) expected for titanium and its alloys.
Characteristics of Beryllium Oxide and Beryllium Metal Powders for Use as Reference Materials
Authors: Stefaniak AB , Hoover MD , Day GA , Ekechukwu AA , Whitney GE , Brink CA , Scripsick RC
Published: August 2005

Laboratory evaluations of commercially available powders of beryllium oxide (BeO) and beryllium metal, with special emphasis on type UOX-125 BeO and type I-400 beryllium metal, are ongoing to develop reference materials for evaluating analytical chemistry digestion methods and facilitating occupational health studies. Measured properties of the powders include morphology, size, density, specific surface area (SSA); crystalline and elemental composition, surface chemistry, and in vitro dissolution in hydrochloric acid (HCl) (pH 1), phagolysosomal simulant fluid (PSF) (pH 4.5), and serum ultrafiltrate (pH 7.3). The powders were also used to evaluate the digestion and recovery efficiencies for commonly used U.S. Environmental Protection Agency (EPA), National Institute for Occupational Safety and Health (NIOSH), and Occupational Safety and Health Administration (OSHA) standard analytical methods. UOX-125 BeO powder has high-purity and aggregate cluster morphology with SSA independent of aerodynamic particle cluster size, which results in dissolution kinetics that are independent of cluster size. I-400 beryllium metal powder has high-purity and compact particle morphology with SSA that increases as particle size decreases, which causes size-dependent dissolution kinetics (i.e., smaller particles dissolve more quickly than larger particles). The PSF and HCl chemical dissolution rate constants (g·cm−2·day−1) for the BeO powder were a factor of 10 lower than for the metal powder. Concomitantly, the EPA and NIOSH analytical methods, which used aggressive digestion procedures (e.g., microwave-assisted sample digestion or perchloric acid), gave more complete recovery of beryllium from BeO compared to the OSHA analytical method. Our characterization data suggest that these BeO and metal powders hold promise for use as analytical reference materials. We recommend continued laboratory collaborations to evaluate and apply these BeO and beryllium metal powders as analytical reference materials.
Deficits in Trace Fear Memory and Long-Term Potentiation in a Mouse Model for Fragile X Syndrome
Authors: Zhao Ming-Gao , Toyoda Hiroki , Ko Shanelle W. , Ding Hoi-Ki , Wu Long-Jun , Zhuo Min
Published: August 2005

Trace fear memory requires the activity of the anterior cingulate cortex (ACC) and is sensitive to attention-distracting stimuli. Fragile X syndrome is the most common form of mental retardation with many patients exhibiting attention deficits. Previous studies in fragile X mental retardation 1 (FMR1) knock-out (KO) mice, a mouse model for fragile X, focused mainly on hippocampal-dependent plasticity and spatial memory. We demonstrate thatFMR1knock-out mice show a defect in trace fear memory without changes in locomotion, anxiety, and pain sensitivity. Whole-cell path-clamp recordings in the ACC show that long-term potentiation (LTP) was completely abolished. A similar decrease in LTP was found in the lateral amygdala, another structure implicated in fear memory. No significant changes were found in basal synaptic transmission. This suggests that synaptic plasticity in the ACC and amygdala ofFMR1KO mice plays an important role in the expression of behavioral phenotypes similar to the symptoms of fragile X syndrome.
Olig2 Directs Astrocyte and Oligodendrocyte Formation in Postnatal Subventricular Zone Cells
Authors: Marshall Christine A. G. , Novitch Bennett G. , Goldman James E.
Published: August 2005

The subventricular zone (SVZ) in the neonatal mammalian forebrain simultaneously generates olfactory interneurons, astrocytes, and oligodendrocytes. The molecular cues that enable SVZ progenitors to generate three distinct cell lineages without a temporal switching mechanism are not known. Here, we demonstrate that the basic helix-loop-helix transcription factor Olig2 plays a central role in this process. Olig2 is specifically expressed in gliogenic progenitors in the postnatal SVZ and by all glial lineages derived from this structure. By expressing normal and dominant-interfering forms of Olig2in vivo, we show that Olig2 repressor function is both sufficient and necessary to prevent neuronal differentiation and to direct SVZ progenitors toward astrocytic and oligodendrocytic fates. Although Olig2 activity has been associated previously with motor neuron and oligodendrocyte development, our findings establish a previously unappreciated role for Olig2 in the development of astrocytes. Furthermore, these results indicate that Olig2 serves a critical role in pan-glial versus neuronal fate decisions in SVZ progenitors, making it the first intrinsic fate determinant shown to operate in the early postnatal SVZ.
Prefrontal Control of the Amygdala
Authors: Likhtik Ekaterina , Pelletier Joe Guillaume , Paz Rony , Paré Denis
Published: August 2005

Accumulating evidence indicates that phobic and posttraumatic anxiety disorders likely result from a failure to extinguish fear memories. Extinction normally depends on a new learning that competes with the original fear memory and is driven by medial prefrontal cortex (mPFC) projections to the amygdala. Although mPFC stimulation was reported to inhibit the central medial (CEm) amygdala neurons that mediate fear responses via their brainstem and hypothalamic projections, it is unclear how this inhibition is generated. Because the mPFC has very sparse projections to CEm output neurons, the mPFC-evoked inhibition of the CEm is likely indirect. Thus, this study tested whether it resulted from a feedforward inhibition of basolateral amygdala (BLA) neurons that normally relay sensory inputs to the CEm. However, our results indicate that mPFC inputs excite rather than inhibit BLA neurons, implying that the inhibition of CEm cells is mediated by an active gating mechanism downstream of the BLA.
Habitat Use by Juvenile Salmonids in the Smith River Estuary, California
Authors: Quiñones Rebecca M. , Mulligan Timothy J.
Published: August 2005

Estuaries are highly productive areas that serve as important nursery habitat for many species of fish. Estuaries provide juvenile salmonids Oncorhynchus spp. with foraging habitats, refuge from predators, and areas in which smoltification and orientation for return migrations can occur. Our primary goal was to describe how juvenile salmonids use the Smith River estuary in northern California, a system that is largely devoid of instream cover and the slough habitat it once contained. The presence of juvenile salmonids was quantified through direct observation (snorkel surveys) and calculations of relative densities in the midchannel and stream margin habitats of the estuary. We completed a total of 755 dives between May 1999 and November 2000. We found that significant differences existed between the relative densities of juvenile Chinook salmon O. tshawytscha and trout (coastal cutthroat trout O. clarkii clarkii and steelhead O. mykiss) observed in habitats with and without cover along stream margins. Stepwise logistic analysis was used to correlate the presence or absence of Chinook salmon and trout to stream reach, habitat type, flow (m3/s), salinity (‰), temperature (°C), and depth (m). In general, juvenile salmonids appeared to preferentially use habitats with overhanging riparian vegetation. However, Chinook salmon presence was most correlated with areas of low salinity (<5‰), while trout presence was most influenced by habitat type. Trout were present most often in stream margin habitats, regardless of other physical factors. Our study demonstrates that riparian vegetation may be an essential component of juvenile salmonid rearing habitat in estuaries with little instream cover.
Temporal Variability in Physical Speciation of Metals during a Winter Rain‐on‐Snow Event
Authors: Morrison Matthew A. , Benoit Gaboury
Published: August 2005

Particulate matter in urban rivers transports a significant fraction of pollutants, changes rapidly during storm events, and is difficult to characterize. In this study, the physical speciation of trace metals and organic C in an urban river and upstream headwaters site in Torrington, CT, were measured during a winter rain‐on‐snow event. In addition, a selective fractionation scheme, using membrane and tangential‐flow ultrafiltration methods to separate suspended particulate matter into sand, silt, clay, and colloid fractions, was evaluated based on the appropriateness of the chosen size categories. During peak runoff at the urban river site, total‐recoverable concentrations of the metals Cu and Pb increased 6‐ and 13‐fold to 16.9 and 9.5 μg L−1, respectively, compared with baseflow concentrations. Concentrations of Cu and Pb reached only 0.9 and 0.86 μg L−1 at the headwaters site. For the measured storm event, the majority of metals were transported by the urban river in association with coarse silt (20–80 μm particle diam.) during peak runoff. During peak runoff at the urban site, organic C associated with the large colloid fraction (0.1–1.0 μm) increased from 5% (at baseflow) to 54% of the total C in transport, whereas dissolved organic C and that associated with smaller colloids decreased from 91.5% (at baseflow) to 41% of the total. Other elements that were monitored as part of the study were Na, K, Ca, Mg, Fe, Mn, Al, Cd, Cl−, NO3−, and SO2−4 The chosen fractionation scheme was useful to characterize pollutant transport during this event, but further testing should be undertaken to determine the most appropriate size range categories, and to ensure that the sizes measured are comparable to those used in other studies.
Long‐Term Effects of Sustained Beef Feedlot Manure Application on Soil Nutrients, Corn Silage Yield, and Nutrient Uptake
Authors: Ferguson Richard B. , Nienaber John A. , Eigenberg Roger A. , Woodbury Brian L.
Published: August 2005

A field study was initiated in 1992 to investigate the long‐term impacts of beef feedlot manure application (composted and uncomposted) on nutrient accumulation and movement in soil, corn silage yield, and nutrient uptake. Two application strategies were compared: providing the annual crop nitrogen (N) requirement (N‐based rate) or crop phosphorus (P) removal (P‐based rate), as well as a comparison to inorganic fertilizer. Additionally, effects of a winter cover crop were evaluated. Irrigated corn (Zea mays L.) was produced annually from 1993 through 2002. Average silage yield and crop nutrient removal were highest with N‐based manure treatments, intermediate with P‐based manure treatments, and least with inorganic N fertilizer. Use of a winter cover crop resulted in silage yield reductions in four of ten years, most likely due to soil moisture depletion in the spring by the cover crop. However, the cover crop did significantly reduce NO3–N accumulation in the shallow vadose zone, particularly in latter years of the study. The composted manure N‐based treatment resulted in significantly greater soil profile NO3–N concentration and higher soil P concentration near the soil surface. The accounting procedure used to calculate N‐based treatment application rates resulted in acceptable soil profile NO3–N concentrations over the short term. While repeated annual manure application to supply the total crop N requirement may be acceptable for this soil for several years, sustained application over many years carries the risk of unacceptable soil P concentrations.
Amendment Effects on Soil Test Phosphorus
Authors: Brauer D. , Aiken G. E. , Pote D. H. , Livingston S. J. , Norton L. D. , Way T. R. , Edwards J. H.
Published: August 2005

Applications of animal manures have increased soil test P values in many parts of the USA and thus increased the risk that soil P will be transferred to surface water and decrease water quality. To continue farming these areas, landowners need tools to reduce the risk of P losses. A field experiment was conducted near Kurten, TX, on a Zulch fine sandy loam (thermic Udertic Paleustalfs) with Bray‐1 P values exceeding 3000 mg P kg−1 soil (dry wt.) in the Ap horizon to evaluate the effectiveness of soil amendments for reducing soil test P values. Soils were amended annually from 1999 to 2001 with 1.5 and 5.0 Mg gypsum ha−1, 1.4 Mg alum ha−1, or 24.4 Mg ha−1 of waste paper product high in Al alone or in combination with 1.5 Mg gypsum ha−1 and/or 1.4 Mg alum ha−1 These treatments supplied a maximum of 225 and 1163 kg ha−1 yr−1 of Al and Ca, respectively. Soil Bray‐1 P and dissolved reactive P levels were monitored from 1999 to 2004. None of the soil amendment treatments affected Bray‐1 P values. Only annual additions of 5.0 Mg gypsum ha−1 from 1999 to 2001 significantly reduced soil dissolved reactive P. Dissolved reactive P levels reached minimal levels after two applications of 5.0 Mg gypsum ha−1 but increased in 2003 and 2004. These results indicate that soil dissolved reactive P levels can be reduced if sufficient amounts of gypsum were added to supply Ca in amounts similar to the soil test P values.
Effects of Commercial Diazinon and Imidacloprid on Microbial Urease Activity in Soil and Sod
Authors: Ingram C. W. , Coyne M. S. , Williams D. W.
Published: August 2005

Diazinon [O,O‐diethyl O‐2‐isopropyl‐6‐methyl(pyrimidine‐4‐yl) phosphorothioate] and imidacloprid [1‐(1‐[6‐chloro‐3‐pyridinyl]methyl)‐N‐nitro‐2‐imidazolidinimine] are applied to lawns for insect control simultaneously with nitrogenous fertilizers such as urea, but their potential effect on urease activity and nitrogen availability in turfgrass management has not been evaluated. Urease activity in enzyme assays, washed cell assays, and soil slurries was examined as a function of insecticide concentration. Intact cores from field sites were used to assess the effect of insecticide application on urease activity in creeping bentgrass (Agrostis palustris Huds.) and bluegrass (Poa pratensis L.) sod. Bacterial urease from Bacillus pasteurii and plant urease from jack bean [Canavalia ensiformis (L.) DC.] were unaffected by the insecticides. Both insecticides inhibited the growth of Proteus vulgaris, a urease‐producing bacterium, but only diazinon significantly reduced urease activity in washed cells; neither insecticide inhibited urease activity in sonicated cells. Neither diazinon nor imidacloprid inhibited urease activity in Woolper soil (fine, mixed, mesic Typic Argiudoll) slurries, but diazinon slightly inhibited urease activity in Maury soil (fine, mixed, semiactive, mesic Typic Paleudalf) slurries. Imidacloprid had no effect on urease activity in creeping bentgrass or bluegrass sod at up to 10 times the commercial application rate. Diazinon briefly, but significantly, reduced urease activity in bluegrass sod. Co‐application of imidacloprid and urea appears to be benign with respect to urease activity in soil and sod. Diazinon, in contrast, appears to have a significant, short‐term, inhibitory effect on the microbial urease‐producing community, but that effect depends on soil type.
Predicting Inter‐Taxa Differences in Plant Uptake of Cesium‐134/137
Authors: Willey Neil J. , Tang Shirong , Watt Nicholas R.
Published: August 2005

For134/137Cs, and many other soil contaminants, research into transfer to plants has focused on particular crops and phytoremediation candidates, producing uptake data for a small proportion of all plant taxa. Despite the significance of differences in uptake between plant taxa, the capacity of soil‐to‐plant transfer models to predict them is currently confined to those taxa for which data exist, there being no method to predict uptake by other taxa. We used residual maximum likelihood (REML) analysis on data from experiments (including 89 plant taxa from China plus 32 phytoremediation candidates) together with data from the literature, to construct a database of relative134/137Cs concentrations in 273 plant taxa. The REML134/137Cs concentrations in plants are not normally distributed but significantly clustered. Analysis of variance (ANOVA), coded with a recent ordinal phylogeny for flowering plants, showed that plant taxa do not behave independently for134/137Cs concentration because 42 and 15% of inter‐taxa differences are associated with phylogeny above the species and ordinal level, respectively. In general, Eudicots, and especially the Caryophyllales, Asterales, and Brassicales, have high134/137Cs concentrations, while the Fabales and Magnoliids, in particular Poales, have low134/137Cs concentrations. Plants of the stress‐tolerant ruderal (S‐R) growth strategysensuGrime have, in general, high concentrations of Cs, while those of the competitive (C) and generalist (C‐S‐R) strategies have low concentrations, although these effects are less pronounced than those of phylogeny. Plant phylogeny and growth strategy might thus be used to predict a significant portion of inter‐taxa differences in plant uptake of134/137Cs.
Runoff Phosphorus Losses from Surface‐Applied Biosolids
Authors: Elliott H. A. , Brandt R. C. , O'Connor G. A.
Published: August 2005

Runoff losses of dissolved and particulate phosphorus (P) may occur when rainfall interacts with manures and biosolids spread on the soil surface. This study compared P levels in runoff losses from soils amended with several P sources, including 10 different biosolids and dairy manure (untreated and treated with Fe or Al salts). Simulated rainfall (71 mm h−1) was applied until 30 min of runoff was collected from soil boxes (100 × 20 × 5 cm) to which the P sources were surfaced applied. Materials were applied to achieve a common plant available nitrogen (PAN) rate of 134 kg PAN ha−1, resulting in total P loading rates from 122 (dairy manure) to 555 (Syracuse N‐Viro biosolids) kg P ha−1 Two biosolids produced via biological phosphorus removal (BPR) wastewater treatment resulted in the highest total dissolved phosphorus (13–21.5 mg TDP L−1) and total phosphorus (18–27.5 mg TP L−1) concentrations in runoff, followed by untreated dairy manure that had statistically (p = 0.05) higher TDP (8.5 mg L−1) and TP (10.9 mg L−1) than seven of the eight other biosolids. The TDP and TP in runoff from six biosolids did not differ significantly from unamended control (0.03 mg TDP L−1; 0.95 mg TP L−1). Highest runoff TDP was associated with P sources low in Al and Fe. Amending dairy manure with Al and Fe salts at 1:1 metal‐to‐P molar ratio reduced runoff TP to control levels. Runoff TDP and TP were not positively correlated to TP application rate unless modified by a weighting factor reflecting the relative solubility of the P source. This suggests site assessment indices should account for the differential solubility of the applied P source to accurately predict the risk of P loss from the wide variety of biosolids materials routinely land applied.
Simulation of Phytoremediation of a TNT‐Contaminated Soil Using the CTSPAC Model
Authors: Ouyang Y. , Shinde D. , Ma L. Q.
Published: August 2005

Knowledge of water movement in the plant‐xylem system and contaminant bioavailability in the soil environment is crucial to evaluate the success of phytoremediation practices. This study investigated the removal of 2,4,6‐trinitrotoluene (TNT) from a contaminated sandy soil by a single poplar (Populus fastigiata) tree through the examinations of temporal variations of xylem water potential, root water uptake, and soil TNT bioavailability. A mathematical model, CTSPAC (Coupled Transport of water, heat, and solutes in the Soil–Plant–Atmosphere Continuum), was modified for the purpose of this study. The model was calibrated using laboratory measurements before its application. Our simulations show that the xylem water potential was high in the roots and low in the leaves with a potential head difference of 3.55 cm H2O, which created a driving force for water flow and chemical transport upward from the roots through the stem to the leaves. The daily average root water uptake rate was 25 cm3 h−1 when an equilibrium condition was reached after 24 h. Our simulations further reveal that no TNT was found in the stem and leaves and only about 1% of total TNT mass was observed in the roots due to the rapid biodegradation and transformation of TNT into its daughter products. About 13% of the soil TNT was removed by the poplar tree, resulting mainly from root uptake since TNT is a recalcitrant compound. In general, the soil TNT bioavailability decreased with time due to the depletion of soil solution TNT by the poplar tree. A constant bioavailability (i.e., 3.1 × 10−6) was obtained in 14 d in which the soil TNT concentration was about 10 mg L−1 Our study suggests that CTSPAC is a useful model to simulate phytoremediation of TNT‐contaminated sites.
Reduction of Copper(II) by Iron(II)
Authors: Matocha C. J. , Karathanasis A. D. , Rakshit S. , Wagner K. M.
Published: August 2005

Laboratory and field investigations have clearly demonstrated the important role of reduced iron (Fe(II)) in reductive transformations of first‐row transition metal species. However, interactions of Fe(II) and copper (Cu) are not clearly understood. This study examined the reduction of Cu(II) by Fe(II) in stirred‐batch experiments at pH 5.2 and 5.5 as influenced by chloride (Cl−) concentration (0.002–0.1 M), initial metal concentration (0.1–9.1 mM), and reaction time (1–60 min) under anoxic conditions. Reduction of Cu(II) to Cu(I) by dissolved Fe(II) was rapid under all experimental conditions and the stability of the products explains the driving force for the redox reaction. Under conditions of low [Cl−] and high initial metal concentration, >40% of total Cu and Fe were removed from solution after 1 min, which accompanied formation of a brownish‐red precipitate. X‐ray diffraction (XRD) patterns of the precipitates revealed the presence of cuprite (Cu2O), a Cu(I) mineral, based on d‐spacings located at 0.248, 0.215, 0.151, and 0.129 nm. Fourier transform infrared (FTIR) spectroscopy corroborated XRD data for the presence of Cu2O, with features located at 518, 625, and 698 cm−1 Increasing [Cl−] stabilized the dissolved Cu(I) product against Cu2O precipitation and resulted in more Fe precipitated from solution (relative to Cu) that appears to be present as poorly crystalline lepidocrocite (γ‐FeOOH). This process may be important in anoxic soil environments, where dissolved Fe(II) levels can accumulate.
Broiler Litter as a Micronutrient Source for Cotton
Authors: Tewolde H. , Sistani K. R. , Rowe D. E.
Published: August 2005

Analytically, poultry litter contains nearly all essential micronutrients but the extent of phytoavailability of these nutrients and whether cotton (Gossypium hirsutum L.) and other crop plants can receive adequate amounts of these nutrients from litter is not fully known. The objective of this research was to determine whether cotton receives sufficient amounts of Fe, Cu, Mn, and Zn from litter and estimate the efficiency of cotton in extracting these metal nutrients from litter in the absence of any other source of the micronutrients. The greenhouse research used plastic pots filled with approximately 11 kg of a 2:1 (v/v) sand to vermiculite growing mix. Cotton (cv. Stoneville 474) was grown in the pots fertilized with broiler litter at rates of 30, 60, 90, or 120 g pot−1 in a factorial combination with four supplemental nutrient solution (NS) treatments. The nutrient solutions consisted of full Hoagland's nutrient solution (NS‐full); a solution of the macronutrients N, P, K, Ca, and Mg (NS‐macro); a solution of the micronutrients Fe, Zn, Mn, Cu, B, and Mo (NS‐micro); and water (NS‐none). Based on tissue nutrient analysis, a one‐time broiler litter application supplied adequate amounts of Fe, Cu, and Mn to bring the concentration of these nutrients in upper leaves within published sufficiency ranges. Zinc, with <17 mg kg−1 concentration in the upper leaves, was the only micronutrient below the established sufficiency range regardless of the rate of applied litter. Cotton extracted Fe and Mn more efficiently than Cu or Zn, removing as much as 8.8% of Fe and 7.2% of Mn supplied by 30 g litter pot−1 In contrast, the extraction efficiency was 1.7% for Cu and 1.9% for Zn. Roots accumulated 58% of the total absorbed Fe and 64% of Cu, and leaves accumulated 32% of the Fe and only 13% of the Cu supplied by litter. In contrast, only 16% of the total absorbed Mn and 23% of Zn accumulated in roots while leaves accumulated 64% of the total Mn and 37% of Zn. These results demonstrate that broiler litter is a valuable source of the metal nutrients supplying Fe, Cu, and Mn in full and Zn in part, but a very large fraction of the litter‐supplied metal nutrients remained in the growing mix.
Process engineering research in China: A multiscale, market‐driven approach
Authors: Ng Ka M. , Li Jinghai , Kwauk Mooson
Published: August 2005

The rapidly evolving Chinese process engineering community and its research are described. A multiscale, market‐driven approach is proposed for its future development. In addition to the science and technology, process engineering is broadened to consider the product, sustainability, business and, most importantly, people issues involved. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Synthesis and characterization of quaternary ammonium ionomers
Authors: Pazhanisamy P. , Ariff Mohamed , Anwaruddin Q.
Published: August 2005

The cationic monomers, MPDMAC16and MPDMAC18, were obtained by quaternization of methacrylamidopropyl–N,N′‐dimethylamine withn‐alkyl iodides (1‐iodohexadecane and 1‐iodooctadecane) in ethyl acetate. Hydrophobic ionomers of MPDMAC16and MPDMAC18with N‐substituted acrylamides were prepared at 60 ± 0.1°C in DMF using AIBN initiator. The cationic monomers and ionomers were characterized by1H‐ and13C‐NMR spectroscopy. The copolymer composition was evaluated from elemental analysis data using carbon/nitrogen (C/N) ratio. The molecular weight distributions of ionomers were obtained from GPC analysis. Both the dilute solution and concentrated solution properties of ionomers were studied by viscometry at 30°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1100–1105, 2005
Effects of preparation method on microstructure and properties of UV‐curable nanocomposite coatings containing silica
Authors: Li Fusheng , Zhou Shuxue , Wu Limin
Published: August 2005

UV‐curable nanocomposites were prepared by the blending method or the in situ method with nanosilica obtained from a sol–gel process. The microstructure and properties of the nanocomposite coatings were investigated using 29Si‐NMR cross‐polarization/magic‐angle spinning, transmission electron microscopy (TEM), Fourier transform IR (FTIR), differential scanning calorimetry (DSC), and UV–visible (UV–vis) spectra, respectively. The NMR and TEM showed that during the blending method, tetraethyl orthosilicate (TEOS) completely hydrolyzed to form nanosilica particles, which were evenly dispersed in the polymer matrix. However, for the in situ method, TEOS partially hydrolyzed to form some kind of microstructure and morphology of inorganic phases intertwisted with organic molecules. FTIR analysis indicated that the nanocomposites prepared from the in situ method had much higher curing rates than those from the blending method. DSC and UV–vis measurements showed that the blending method caused higher glass‐transition temperatures and UV absorbance than the in situ method. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1119–1124, 2005
Electrical properties and morphology of polypropylene/epoxy/glass fiber composites filled with carbon black
Authors: Li Ying , Wang Shifeng , Zhang Yong , Zhang Yinxi
Published: August 2005

The volume resistivity and percolation thresholds of carbon black (CB) filled polypropylene (PP), PP/epoxy, and PP/epoxy/glass fiber (GF) composites were measured. The morphology of these conductive polymer composites was studied with scanning electron microscopy (SEM). The effects of the GF and epoxy contents on the volume resistivity were also investigated. The PP/epoxy/GF/CB composite exhibited a reduced percolation threshold, in comparison with that of the PP/CB and PP/epoxy/CB composites. At a given CB content, the PP/epoxy/GF/CB composite had a lower volume resistivity than the PP/CB and PP/epoxy/CB composites. SEM micrographs showed that CB aggregates formed chainlike structures and dispersed homogeneously within the PP matrix. The addition of the epoxy resin to PP resulted in the preferential location of CB in epoxy, whereas in the PP/epoxy/GF multiphase blends, because of the good affinity of CB to epoxy and of epoxy to GF, CB particles were located in the epoxy phase coated on GF. The decreased percolation threshold and volume resistivity indicated that conductive paths existed in the PP/epoxy/GF/CB composite. The conductive paths were probably formed through the interconnection of GF. Appropriate amounts of GF and epoxy should be used to decrease the volume resistivity and provide sufficient epoxy coating. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1142–1149, 2005
New polymeric materials for paper and textile conservation. I. Synthesis and characterization of acrylic copolymers
Authors: Princi Elisabetta , Vicini Silvia , Pedemonte Enrico , Arrighi Valeria , McEwen Iain
Published: August 2005

In the preservation of cultural heritage items, the use of polymeric materials for the consolidation and protection of artifacts with historical and artistic value is widely accepted. This area is vast and includes studies of various objects made of different materials such as wood, stone, textiles, and paper. The aim of this article is to establish the most suitable copolymer for cellulose‐based‐material restoration according to its properties, as evaluated by several techniques such as 1H‐NMR spectroscopy, size exclusion chromatography, differential scanning calorimetry, and dynamic mechanical analysis. In addition to the mechanical property evaluation, an investigation of fungal deterioration has been carried out. Because, in the literature, no complete study concerning the characterization of ethyl acrylate/methyl methacrylate and butyl acrylate/methyl methacrylate copolymers is available, a detailed and full investigation of these polymers is required before the best copolymer is selected for grafting polymerization onto cellulose. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1157–1164, 2005
Synthesis and characterization of polyacrylamide grafted copolymers of Kundoor mucilage
Authors: Mishra Anuradha , Bajpai Malvika
Published: August 2005

In the present research, grafting of acrylamide monomer onto a water‐soluble food grade polysaccharide, Kundoor mucilage, initiated by ceric ion in aqueous medium has been studied under N2 atmosphere. Ceric ion initiated solution polymerization was found to be satisfactory for the formation of copolymer. The effect of monomer concentration, initiator concentration, reaction time, and temperature, in terms of grafting efficiency (%GE) and percent of grafting (%PG), have been investigated. The graft copolymers were characterized by FTIR, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X‐ray diffraction (XRD). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1186–1191, 2005
Synthesis of C60‐bonded polystyrene initiated with C60Cln/Ni(naph)2/P(Ph)3
Authors: Hua Jing , Yang Haiqiang , Guo Zhixin , Xu Ling , Chen Dianbao
Published: August 2005

A linear‐shaped polystyrene with C60 core was prepared with a novel initiator system, C60Cln (n average value is 20)/Ni(naph)2/P(Ph)3, and Tp was 130 °C. The results of gel‐permeation chromatography detected by UV detector and fluorescence spectrum of C60‐PSt demonstrated that C60 was chemically bonded to polystyrene. The linear increasing of molecular weights (Mn,GPC) with conversion indicated that this novel initiator system had some characters of living polymerization. A bathochromic shift was found in the UV–vis spectra curves with increasing concentration of C60‐PSt in THF solution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1215–1218, 2005