bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiport Sock Samplers: A Low‐Cost Technology for Effective Multilevel Ground Water Sampling
Authors: Jones Ian , Lerner David N. , Baines Owen P.
Published: February 2007

The importance of obtaining depth‐specific ground water samples is now well recognized among practitioners and scientists alike. Many methods and technologies are available for level discrete or depth‐specific ground water sampling in consolidated aquifers. All methods have their associated advantages and drawbacks, however. One common disadvantage is that they are expensive. A large number of point discrete ground water samples were required for a UK research project aimed at quantifying natural attenuation processes in ground water contaminated by a former coal carbonization plant. Based on experience from a previous project to develop novel level accurate sampling methodologies for use in existing boreholes, the Ground Water Protection and Restoration Research Unit (GWPRRU) produced and tested a low‐cost design multiport sock sampler for ground water monitoring. The sock sampler design allowed the recovery of multiple depth‐specific ground water samples from depths of 150 feel (45 m) from individual boreholes in the sandstone aquifer at the field site. Because of their use of inexpensive materials, simple design, installation and use that does not require gravel packs, packers, or grouting, sock samplers were found to be the most cost effective, convenient, and reliable method of obtaining multiple depth‐specific ground water samples at the project field site.
Other Types of Contamination
Authors: Nyer Evan K. , Carman Eric P. , Flynn Raymond M.
Published: February 2007

“Hazardous levels of methane in the subsurface occur at numerous locations across the United States.”
Removal of Perchloroethylene from a Layered Soil System by Steam Flushing
Authors: She Hugh Y. , Sleep Brent E.
Published: February 2007

Steam flushing experiments were concluded in a two‐dimensional chamber containing two layers of F75 silica sand separated by a layer of finer F10 silica sand. Perchloroelhylene (PCE), which had spilled into the chamber under water‐saturated conditions, formed a pool on the F110 sand layer. Steam was injected above the F110 sand layer. Temperatures, moisture content, and PCE concentrations in the chamber were monitored. Samples, taken from the various locations in the sand chamber, indicated that complete removal of PCE from the steam zone was achieved, with an 84% overall recovery. Some downward displacement of PCE‐contaminated water through the F110 sand layer was observed and a small amount of gravity override occurred. Channeling of steam was minimal. The experiment indicates that steam flushing may be used successfully for removal of PCE from relatively homogeneous soils. Issues of gravity override and downward mobilization of contaminants must be considered in applying steam flushing at the field scale.
Elements in Cottonwood Trees as an Indicator of Ground Water Contaminated by Landfill Leachate
Authors: Erdman James A. , Christenson Scott
Published: February 2007

Ground water at the Norman Landfill Research Site is contaminated by a leachate plume emanating from a closed, unlined landfill formerly operated by the city of Norman, Oklahoma, Ground water contaminated by the leachate plume is known to be elevated in the concentration of many, organic and inorganic constituents. Specific conductance, alkalinity, chloride, dissolved organic carbon, boron, sodium, strontium, and deuterium in ground water are considered to be indicators of the leachate plume at this site.

Leaf samples of broad‐leafed cottonwood, Populus deltoides, were collected from 57 sites around the closed landfill. Cottonwood, a phreatophyte or “well plant,” functions as a & surrogate well and serves as a ground water quality sampler. The leaf samples were combusted to ash and analyzed by instrumental neutron activation for 35 elements and by prompt‐gamma instrumental neutron activation, for boron. A monitoring well was located within a few meters of a sampled cottonwood tree at 15 of the 57 sites, and ground water samples were collected from these monitoring wells simultaneously with a leaf sample. The chemical analyses of the ground water and leaf samples from these 15 sites indicated that boron, bromine, sodium, and strontium concentrations in leaves were significantly correlated with leachate indicator constituents in ground water. A point‐plot map of selected percentiles indicated high concentrations of boron, bromine, and sodium in leaf ash from sites downgradient of the most recent landfill and from older landfills nearby.

Data from leaf analysis greatly extended the known areal extent of the leachate plume previously determined from a network of monitoring wells and geophysical surveys. This phytosgeochemical study provided a cost‐effective method for assessing the extent of a leachate plume from an old landfill. Such a method may be useful as a preliminary sampling tool to guide the design of hydrogeochemical and geophysical studies.
Creation of a Subsurface Permeable Treatment Zone for Aqueous Chromate Contamination Using In Situ Redox Manipulation
Authors: Fruchter J.S. , Cole C.R. , Williams M.D. , Vermeul V.R. , Amonette J.E. , Szecsody J.E. , Istok J.D. , Humphrey M.D.
Published: February 2007

An in situ redox manipulation (ISRM) method for creating a permeable treatment zone in the subsurface has been developed at the laboratory bench and intermediate scales and deployed at the field scale for reduction/immobilization of chrornate contamination. At other sites, the same redox technology is currently being tested for dechlorination of TCE. The reduced zone is created by injected reagents that reduce iron naturally present in the aquifer sediments from Fe(III) to surface‐bound and structural Fe(II) species. Standard ground water wells are used, allowing treatment of contaminants too deep below the ground surface for conventional treneh‐and‐fill technologies.

A proof‐of‐principle field experiment was conducted in September 1995 at a chromate (hexavalent chromium) contaminated ground water site on the Hartford Site in Washington. The test created a 15 m (˜50 feet) diameter cylindrical treatment zone. The three phases of the test consisted of (1) injection of 77, 000 L (20, 500 gallons) of buffered sodium dithionite solution in 17.1 hours, (2) reaction for 18.5 hours, and (3) withdrawal of 375, 000 L (99, 600 gallons) in 83 hours. The withdrawal phase recovered 87% to 90% of the reaction products. Analysis of post‐experimental sediment cores indicated that 60% to 100% of the available reactive iron in the treated zone was reduced. The longevity of the reduced zone is estimated between seven and 12 years based on the post‐experiment core samples. Three and half years after the field test, the treatment zone remains anoxic, and hexavalent chromium levels have been reduced from 0.060 mg/L to below detection limits (0.008 mg/L). Additionally, no significant permeability changes have been detected during any phase of the experiment.
Spatial and Temporal Variability in Seepage Between a Contaminated Aquifer and Tributaries to the Ohio River
Authors: Fryar Alan E. , Wallin Eric J. , Brown David L.
Published: February 2007

Although ground water discharge‐can limit plume migration and transfer contaminants to streams, interactions among ground water, rivers, and tributaries in contaminated watersheds have received relatively little attention. We used multiple methods to delineate seepage along Little Bayou and Bayou Creeks, tributaries to the Ohio River in McCracken County, Kentucky, from July 1996 through July 1998. The Paducah Gaseous Diffusion Plant (PGDP) lies between the creeks. Trichloroethene (TCE) and technetium‐99 plumes within the underlying Regional Gravel Aquifer (RGA) extend several kilometers from PGDP toward the river. Both creeks tend to gain flow where they are incised into the RGA or contiguous strata in the Ohio flood plain. Bayou Creek also gains flow upstream of PGDP; other reaches of both creeks tend to lose flow. Local storms, river floods, and seasonal dry periods caused temporary changes in seepage rates and reversals in hydraulic gradients. Gaining conditions were indicated by seeps, springs, and boils, by upward hydraulic gradients from bank wells and bed piezometers to the stream, and by mixing models using chloride and oxygen‐18. Mixing models and downward hydraulic gradients from the stream to wells indicated losing conditions. Annual ranges of stream, bed, and bank temperatures tended to be narrower, bed and bank temperatures in summer and early autumn tended to be cooler, and maximum values of specific discharge measured by seepage meters were greater along gaining than along losing reaches. Estimates of specific discharge from stream gauging and one‐dimensional flow‐modeling did not conclusively identify losing and gaining reaches, but absolute values of those estimates fell within the range of seepage‐meter measurements. Contaminants discharging to Little Bayou Creek were diluted downstream by uncontaminated ground water. Volatilization, biodegradation, or sorption probably removed TCE from stream water. These results indicate that discharge to tributaries can limit seepage of contaminants to rivers.
Site‐Specific Design for Dual Phase Recovery and Stabilization of Pooled DNAPL
Authors: Gerhard Jason I. , Kueper Bernard H. , Hecox Gary R. , Schwarz Eric J.
Published: February 2007

Volume reduction and lowering of capillary pressure within a large DNAPL pool are utilized as objectives in the design of a large‐scale dual phase recovery system at a chemical manufacturing facility in the United States. By reducing DNAPL pool height through mass removal, capillary pressure is lowered, resulting in a reduced potential for future vertical and horizontal mobilization of the chlorinated solvent DNAPL pool. The DNAPL pool extends over an approximately 200 m by 275 m area in low permeability fill deposits overlying a clay aquitard. A three‐dimensional multiphase flow model was employed to arrive at a final design incorporating nine horizontal drains (total length 664 m) and a pulsed pumping system. The numerical model was calibrated to the results of a 42‐day field pilot‐test involving the removal of approximately 25,000 L of DNAPL from a single, 55 m long horizontal drain. Numerical simulation revealed that gravity drainage, as opposed to hydraulic gradients in the water phase, is the dominant recovery mechanism at this site. This stems from the relatively high density and the viscosity of the DNAPL, and the relatively low permeability of the formation deposits. The use of pulsed pumping is shown to reduce the volume of contaminated ground water recovered from the 9‐drain system, without significant reduction of the total volume of DNAPL recovered.
Limitations of ROI Testing for Venting Design: Description of an Alternative Approach Based on Attainment of a Critical Pore‐Gas Velocity in Contaminated Media
Authors: DiGiulio Dominic C. , Varadhan Ravi
Published: February 2007

We utilize data from a Superfund site where radius of influence (ROI) testing was conducted in support of a venting design to describe limitations of ROI evaluation in more detail than has been done previously, and to propose an alternative method of design based on specification and attainment of a critical pore‐gas velocity in contaminated subsurface media. Since accurate gas permeability estimation is critical to pore‐gas velocity computation, we assess the usefulness of ROI testing data on estimation of radial permeability, vertical permeability, and leakance. We apply information from published studies on rate‐limited vapor transport to provide the basis for selection of a critical design pore‐gas velocity for soils at this site. Using single‐well gas flow simulations, we evaluate whether this critical pore‐gas velocity was achieved at measured ROIs. We then conduct a series of multi‐well gas flow simulations to assess how variation in anisotropy and leakance affect three‐dimensional vacuum and pore‐gas velocity profiles and determination of an ROI. Finally, when attempting to achieve a critical design pore‐gas velocity we evaluate whether it is more efficient to install additional wells or pump existing wells at a higher flow rate.
A Graphical Approach for Determining Dilution‐Attenuation Factors: Basic Theory and Approach for Submerged Sources
Authors: Abrano ic David , Johnson Paul C. , Charbeneau Randall. J. , Hemstreet Timothy J.
Published: February 2007

The dilution attenuation factor (DAF) is a quantity used to relate the concentration of leachate leaving a source zone (e.g., landfill, impoundment, or contaminated soils) to its impact on down‐gradient ground water quality. The DAF is of importance because it plays a key role in U.S. Environmental Protection Agency (EPA)'s methodologies for developing soil cleanup goals and for managing hazardous wastes. In this work, a simplistic graphically‐based approach for determining site‐specific and generic DAFs was developed. In this case the DAF is based on time‐and vertically‐averaged concentrations along the plume centerline, and the mathematical framework employs well‐known analytical and semianalytical solutions for dissolved contaminant transport. Finite sources with a range of decay characteristics are allowed for. One unique feature of this work is that the graphical approach allows for varying levels of sitespecificity, and thus can be used when one has a little, or a lot, of site‐specific information. The graphs visually indicate the sensitivity to various parameters, which is valuable information not easily gleaned from most numerical software simulators. This approach is, however, not applicable to very complex hydrogeologic settings (e.g., fractured geology), or to ground water flows that cannot be reasonably approximated as one‐dimensional.
Implications of Subsurface Heterogeneity at a Potential Monitored Natural Attenuation Site
Authors: Hurt Kelly L. , Beck Frank P. , Wilson John T.
Published: February 2007

Direct‐push sampling was conducted at a site previously characterized with conventional monitoring wells. Hydrogeological and chemical heterogeneities not represented in the original site conceptual model were detected by direct‐push sampling. These heterogeneities were important in terms of their impact on the assessment of monitored natural attenuation at the site. This research suggests that additional sampling efforts could be attempted at some sites to test the accuracy of site conceptual models. The leading edge of a contaminant plume must be examined closely, because conceptual errors in this area could easily allow impacts to receptors to remain undetected.
Successful Use of an Innovative Horizontal/Vertical Well Couplet in Fractured Bedrock to Intercept a Mobile Gasoline Plume
Authors: Carlisle Dana , Cook David A. , Miller James A.
Published: February 2007

The horizontal directional drilling (HDD) technology was successfully used in a fracture‐controlled sandstone matrix to intercept a gasoline plume and create a 150‐foot‐long hydrodynamic barrier preventing seepage of gasoline and contaminated ground water into a salmon‐bearing stream within a public park. A 36‐foot‐deep vertical recovery well (VW) intercepts the central low point of the 420‐foot‐long HDD borehole to pump recovered fluids. Contaminant seepage into the creek ceased within hours of starting up the HDD/VW interceptor system in August 1999. Approximately 325 gallons of gasoline and 2 million gallons of contaminated ground water have been recovered to date.
Ethanol‐Stimulated Bioremediation of Nitrate‐Contaminated Ground Water
Authors: Tartakovsky B. , Millette D. , Del Isle S. , Guiot S.R.
Published: February 2007

Extensive characterization of a nitrate‐contaminated site at a Canadian airport revealed that natural attenuation of the plume was limited due to aerobic conditions. However, nitrate removal rates as high as 1.4 mg‐N/(L/day) were observed in batch tests carried out under denitrifying conditions with an added carbon source. On the basis of these results, a field denitrification pilot test using a setup of vertical withdrawal and injection wells was carried out. Ethanol was used as a carbon source to stimulate the growth and activity of indigenous denitrifying bacterial populations. Denitrification rates of up to 1.2 mg‐N/(L/day) were achieved during the test. The test confirmed the feasibility of the technology, which uses the indigenous bacterial populations for denitrification and transforms the aquifer into a subsurface bioreactor.
Abandoned Underground Storage Tank Location Using Fluxgate Magnetic Surveying: A Case Study
Authors: Van Biersel Thomas P. , Bristoll Bill C. , Taylor Robert W. , Rose James
Published: February 2007

In 1993, during the removal of a diesel and a gasoline underground storage tank at the municipal garage of the Village of Kohler, Sheboygan County, Wisconsin, soil testing revealed environmental contamination at the site. A site investigation revealed the possibility of a second on‐site source of petroleum contamination. Limited historical data and the present usage of structures within the suspected source area precluded the use of most invasive sampling methods and most geophysical techniques. A fluxgate magnetometer survey, followed by confirmatory excavation, was conducted at the site. The fluxgate magnetometer survey identified nine possible magnetic anomalies within the 18 × 25 m area. The subsequent excavation near the anomalies revealed the presence of five paired and two individual 2000 L underground storage tanks. The fluxgate magnetometer survey, although affected by the proximity of buildings, was able to detect the buried tanks within 3 m of the brick structures, using a 1.5 × 1.5 m sampling array.
Importance of Nonequilibrium Sorption Conditions: Contaminated Soil
Authors: Opdyke Daniel R. , Loehr Raymond C.
Published: February 2007

When modeling the fate and transport of chemicals in ground water, a common assumption is that sorption equilibrium is achieved rapidly. This local equilibrium assumption is valid when the rate of chemical sorption to soil particles is more rapid than the rate of aqueous chemical change by other processes. However, for some chemicals (e.g., weathered hydrocarbons) this assumption is not necessarily correct. As a result, an increasing body of knowledge related to the extent and rate of release (ROR) of hydrocarbons from soil has been generated.

When evaluating site remediation options, it is important to know when nonequilibrium sorption conditions may have a significant impact on such decisions. In this study, a tiered procedure was developed to consistently evaluate the importance of ROR information at a site. The procedure consists of three tiers, each requiring more information and computational effort than the previous one. The first tier employs three power‐law relationships between site parameters and the importance of ROR kinetics to quickly and easily estimate the importance of ROR information at a site. The second tier involves running and evaluating the deterministic component of a ground water fate and transport model. The third tier involves running and evaluating the probabilistic component of the ground water model. Given the sequential nature of the procedure, it is not necessary to perform Tier II (or Tier III) unless the Tier I (or Tier II) evaluation indicates that ROR kinetics may be important at the specific site under consideration. An example of applying the Tier I analysis to a specific site is provided. The results illustrate the influence of the chemical removal processes (e.g., advection and biodegradation) on the predicted importance of ROR kinetics. For the site considered, ROR kinetics had an important impact on model predictions when the biodegradation rate was high.
Evaluation of the Johnson and Ettinger Model for Prediction of Indoor Air Quality
Authors: Hers Ian , Zapf‐Gilje Reidar , Johnson Paul C. , Li Loretta
Published: February 2007

Screening level models are now commonly used to estimate vapor intrusion for subsurface volatile organic compounds (VQCs). Significant uncertainty is associated with processes and models and, to date, there has been only limited field‐based evaluation of models for this pathway. To address these limitations, a comprehensive evaluation of the Johnson and Ettinger (J&E) model is provided through sensitivity analysis, comparisons of model‐predicted to measured vapor intrusion for 11 petroleum hydrocarbon and chlorinated solvent sites, and review of radon and flux chamber studies. Significant intrusion was measured at five of 12 sites with measured vapor attenuation ratios (αm's) (indoor air/source vapor) ranging from ∼1 × 10−6 to 1 × 10−4. Higher attenuation ratios were measured for studies using radon, inert tracers, and flux chambers; however, these ratios are conservative owing to boundary conditions and tracer properties that are different than those at most VOC‐contaminated sites. Reasonable predictions were obtained using the J&E model with comparisons indicating that model‐predicted vapor attenuation ratios (αp's) were on the same order, or less than the αm's. For several sites, the αm were approximately two orders of magnitude less than the αp's indicating that the J&E model is conservative in these cases. The model comparisons highlight the importance in using appropriate input parameters for the J&E model. The regulatory implications associated with use of the J&E model to derive screening criteria are also discussed.
Geochemical Changes in Ground Water Due to Landfill Gas Effects
Authors: Kerfoot Henry B. , Baker John A. , Burt David M.
Published: February 2007

Concentrations of dissolved inorganic constituents commonly monitored in ground waters at landfills were evaluated during and after a period of landfill gas effects on the ground water. Landfill gas can potentially act as an acid or as a reducing agent (Lewis base) due to its carbon dioxide and methane content, respectively. Ground water data from a single landfill gas‐affected well were used to evaluate the correlation of the total volatile organic compound (VOC) concentration (as a general measure of landfill gas effects) with bicarbonate alkalinity, ammonia, calcium, iron, magnesium, manganese, sodium, chloride, and sulfate concentrations. Bicarbonate alkalinity, calcium, and magnesium concentrations were correlated with total VOC concentrations. The correlation with calcium and magnesium concentrations is attributed to increased dissolution of carbonate minerals by carbonic acid from the landfill gas carbon dioxide. Total manganese concentrations also increased with increasing VOC content. This is attributed to reduction of manganese (IV) in aquifer minerals by methane in the landfill gas. No detectable iron was observed during the landfill gas effects or after successful corrective action, suggesting that the redox potential of the ground water was not sufficiently low to reduce iron (III) minerals. There was no correlation observed between total VOC concentrations and chloride, sodium, or sulfate concentrations, and there were insufficient ammonia detections to evaluate. The observed effects of landfill gas are expected to depend on the particular mineralogy and ground water quality of a site. These results and basic chemical principles, however, suggest that landfill gas effects on ground water could cause an increase in bicarbonate alkalinity, calcium, and magnesium concentrations, without increases in sodium or chloride concentrations at many sites. Because municipal solid waste landfill leachate is typically characterized by concentrations of chloride and sodium that are significantly elevated relative to background ground water concentrations, landfill gas effects on ground water could potentially be differentiated from leachate effects by a lack of increases in sodium or chloride concentrations accompanying VOC detections.
Modeling a Ground Water Circulation Well Alternative
Authors: Elmore Andrew Curtis , DeAngelis Luca
Published: February 2007

Ground water circulation wells (GCWs) provide an appealing alternative to typical pump‐and‐treat ground water remediation systems because of the inherent resource‐conservative nature of the GCW systems. GCW performance prediction is challenging because the consideration of extraction and recharge in a single well is unusual for most practitioners, the technology is relatively new, and a meaningful body of literature has not been published. A three‐part evaluation process using state‐of‐the‐practice numerical ground water flow and mass transport models was developed for application during GCW pilot studies at the former Nebraska Ordnance Plant site. A small‐scale ground water flow model was developed during the pilot study planning process to predict the system performance and to locate performance‐measuring monitoring wells. Key predictions included the capture zone predicted to develop upgradient of the GCW, the downgradierit GCW recharge zone, and the circulation zone centered on the GCW. The flow model was subsequently verified using ground water elevation data and contaminant concentration data collected during pilot study operation. Aquifer parameters were reestimated as a result of the verification process. Those parameter values were used as input to a larger scale model, which was used to develop a remedial alternative consisting of multiple GCW systems.
Vertical Delineation of Contamination in Fractured Bedrock Aquifer
Authors: Muscalo David
Published: February 2007

The New Jersey Department of Environmental Protection's Technical Regulations require the horizontal and vertical delineation of contamination. Monitor wells screened at increasingly deeper intervals are used to delineate vertical contamination. In New Jersey, the open interval in a bedrock well cannot exceed 7.6 m. Since contamination has been found at depths as great as 91.4 m in a production well in the study area, it would be prohibitively expensive to install monitor wells with 7.6 m open holes at ever‐increasing depths until no contamination was found. Isolation of discrete zones in boreholes using pneumatic packers was implemented at a site in north central New Jersey. Ground water samples were collected from selected 6.1 m sections of boreholes drilled into fractured bedrock at three locations on the property and one offsite location. The ground water samples were analyzed in a field laboratory. The analytical results were used to determine the vertical extent of gasoline‐related compounds dissolved in the ground water on the property and offsite. These compounds include benzene, ethylbenzene, methyl tertiary butyl ether, toluene, and xylenes. The four boreholes were converted into bedrock monitor wells. The intake interval for each of the wells was selected through evaluation of the vertical distribution of contaminants as determined from analytical results obtained from a field laboratory located onsite. Three wells are used for the recovery of contaminated ground water. The recovered water will be treated at the onsite air‐stripping unit. The fourth well is used to chemically and hydraulically monitor the progress of the ground water recovery program.
A FIELD‐BASED METHOD FOR ESTIMATING AGE IN FREE‐RANGING STELLER SEA LIONS (EUMETOPIAS JUBATUS) LESS THAN TWENTY‐FOUR MONTHS OF AGE
Authors: King James C. , Gelatt Thomas S. , Pitcher Kenneth W. , Pendleton Grey W.
Published: February 2007

Abstract

Studies of health, survival, and development of juvenile Alaskan Steller sea lions (Eumetopias jubatus, SSL) require accurate estimates of age for wild‐captured animals. However, the value and accuracy of several potential predictors of age have not been assessed with data from known‐age free‐ranging animals. During 2001–2005, forty‐six individual SSL originally branded or tagged at ≤6 mo of age were recaptured by the Alaska Department of Fish and Game (ADF&G). Using a series of general linear models, we evaluated the ability of morphometrics measurements: permanent canine tooth length (CTL), diastema (DIAS), whisker length (WHIS), and dorsal standard length (DSL) to predict the age of forty‐six known‐age juveniles (n= 46 ≤23 mo of age). Permanent CTL was the strongest individual predictor (r2= 0.80); followed by DSL, DIAS, and WHIS (r2= 0.70, 0.56, and 0.45, respectively). The inclusion of a single sample from a 44‐mo‐old sea lion suggested quadratic relationships between age and all predictors for older animals. Only models including CTL predicted age to within 6 mo of known age. The equation Age = (−3.0112 +[0.6726 * CTL]+[0.4965 * DIAS]) allows for accurate age estimates of SSL ≤23 mo for both sexes.
Sensory and Physiochemical Characteristics of Frankfurters Formulated with Potassium Lactate and Sodium Diacetate before and after Irradiation
Authors: Knight T.D. , Miller R. , Maxim J. , Keeton J.T.
Published: February 2007

ABSTRACT:  Quality attributes were evaluated for irradiated (0, 1.8, or 2.6 kGy) frankfurters formulated with 0% or 3% potassium lactate/sodium diacetate solution and stored aerobically or vacuum packaged at 4 °C for 4 or 8 wk, respectively. Quality analyses included descriptive sensory panel, pH, L*a*b* color values, and TBARS determination. Aroma and flavor quality were retained for aerobically stored frankfurters with lactate/diacetate throughout shelf‐life. Meaty/brothy complex aroma and flavor, smoke aroma and aftertaste, spice aroma and flavor, astringency, sourness, bitterness, springiness, cohesiveness, and juiciness attributes were lower for aerobically stored frankfurters formulated without lactate/diacetate compared to those with lactate/diacetate toward the end of storage. Sensory color and other quality attributes were minimally influenced by either treatment. Addition of lactate/diacetate and irradiation were also effective shelf‐life extenders for vacuum‐packaged frankfurters. There were fewer influences on sensory characteristics for vacuum‐packaged frankfurters compared to those that were aerobically packaged. However, small yet significant differences were detected by sensory panelists for some aroma and flavor attributes, which remained consistent between treatments throughout storage. Sensory and instrumental color scores varied slightly, but were fairly consistent throughout vacuum‐packaged storage. Overall, lactate/diacetate retarded deterioration of frankfurters throughout aerobic storage and helped maintain quality with or without irradiation for vacuum‐packaged frankfurters.
Characterization of Hydrophobic Flavor Release Profile in Oil‐in‐Water Emulsions
Authors: Giroux H.J. , Perreault V. , Britten M.
Published: February 2007

ABSTRACT:  An instrumental approach to better understand the release and persistence of flavor in oil‐in‐water emulsions has been developed. Emulsions were prepared with various whey protein (0.1% to 3.16%), sunflower oil (1% to 8%), and ethyl hexanoate (0% to 0.04%) concentrations. Flavor release profile in real time was measured at 37 °C using a specially designed glass cell connected directly to a gas chromatograph equipped with a flame ionization detector. The intensity of flavor released from the emulsion stirred at a shear rate of 100  s−1 was monitored as a function of time and data were fitted to a 1st‐order kinetic equation. Maximum intensity and decay rate constant were both determined from the model and the persistence index (inversely associated to decay rate constant) was calculated. For constant aroma concentration in the emulsion, maximum intensity significantly decreased as whey protein and oil concentrations increased. For increasing aroma concentration, maximum intensity was directly proportional to the ethyl hexanoate concentration when the oil content was kept constant but leveled off when oil content was increased. Persistence of flavor significantly increased with increasing protein and oil concentrations while aroma concentrations had no effect when oil content was constant. The results showed that oil concentration had a greater influence on flavor release characteristics than protein concentration. Aroma concentration in the oil phase, rather than in the emulsion, determines the kinetics of hydrophobic flavor release. The method provides a useful tool for the rapid and reproducible measurement of flavor release profile.
The role of synaptotagmin I C2A calcium‐binding domain in synaptic vesicle clustering during synapse formation
Authors: Gardzinski Peter , Lee David W. K. , Fei Guang‐He , Hui Kwokyin , Huang Guan J. , Sun Hong‐Shuo , Feng Zhong‐Ping
Published: February 2007

Synaptic vesicles aggregate at the presynaptic terminal during synapse formation via mechanisms that are poorly understood. Here we have investigated the role of the putative calcium sensor synaptotagmin I in vesicle aggregation during the formation of soma–soma synapses between identified partner cells using a simple in vitro synapse model in the mollusc Lymnaea stagnalis. Immunocytochemistry, optical imaging and electrophysiological recording techniques were used to monitor synapse formation and vesicle localization. Within 6 h, contact between appropriate synaptic partner cells up‐regulated global synaptotagmin I expression, and induced a localized aggregation of synaptotagmin I at the contact site. Cell contacts between non‐synaptic partner cells did not affect synaptotagmin I expression. Application of an human immunodeficiency virus type‐1 transactivator (HIV‐1 TAT)‐tagged peptide corresponding to loop 3 of the synaptotagmin I C2A domain prevented synaptic vesicle aggregation and synapse formation. By contrast, a TAT‐tagged peptide containing the calcium‐binding motif of the C2B domain did not affect synaptic vesicle aggregation or synapse formation. Calcium imaging with Fura‐2 demonstrated that TAT–C2 peptides did not alter either basal or evoked intracellular calcium levels. These results demonstrate that contact with an appropriate target cell is necessary to initiate synaptic vesicle aggregation during nascent synapse formation and that the initial aggregation of synaptic vesicles is dependent on loop 3 of the C2A domain of synaptotagmin I.
A conductive pathway generated from fragments of the human red cell anion exchanger AE1
Authors: Parker Mark D. , Young Mark T. , Daly Christopher M. , Meech Robert W. , Boron Walter F. , Tanner Michael J. A.
Published: February 2007

Human red cell anion exchanger AE1 (band 3) is an electroneutral Cl–HCO3− exchanger with 12–14 transmembrane spans (TMs). Previous work using Xenopus oocytes has shown that two co‐expressed fragments of AE1 lacking TMs 6 and 7 are capable of forming a stilbene disulphonate‐sensitive 36Cl‐influx pathway, reminiscent of intact AE1. In the present study, we create a single construct, AE1Δ(6: 7), representing the intact protein lacking TMs 6 and 7. We expressed this construct in Xenopus oocytes and evaluated it employing a combination of two‐electrode voltage clamp and pH‐sensitive microelectrodes. We found that, whereas AE1Δ(6: 7) has some electroneutral Cl–base exchange activity, the protein also forms a novel anion‐conductive pathway that is blocked by DIDS. The mutation Lys539Ala at the covalent DIDS‐reaction site of AE1 reduced the DIDS sensitivity, demonstrating that (1) the conductive pathway is intrinsic to AE1Δ(6: 7) and (2) the conductive pathway has some commonality with the electroneutral anion‐exchange pathway. The conductance has an anion‐permeability sequence: NO3−≈ I− > NO2− > Br− > Cl− > SO42−≈ HCO3−≈ gluconate−≈ aspartate−≈ cyclamate−. It may also have a limited permeability to Na+ and the zwitterion taurine. Although this conductive pathway is not a usual feature of intact mammalian AE1, it shares many properties with the anion‐conductive pathways intrinsic to two other Cl–HCO3− exchangers, trout AE1 and mammalian SLC26A7.
Lifetime Distribution Estimation of Boot Seals in Automotive Applications by Bayesian Method
Authors: Guerin Fabrice , Hambli Ridha
Published: February 2007

The constantly increasing market requirements of high quality vehicles ask for the automotive manufacturers to perform lifetime testing to verify the reliability levels of new products. A common problem is that only a small number of examples of a component of system can be tested. In the automotive applications, mechanical components subjected to cyclic loading have to be designed against fatigue. Boot seals are used to protect velocity joint and steering mechanisms in automobiles. These flexible components must accommodate the motions associated with angulation of the steering mechanism. Some regions of the boot seal are always in contact with an internal metal shaft, while other areas come into contact with the metal shaft during angulation. In addition, the boot seal may also come into contact with itself, both internally and externally. The contacting regions affect the performance and longevity of the boot seal. In this paper, the Bayesian estimation of lognormal distribution parameters (usually used to define the fatigue lifetime of rubber components) is studied to improve the accuracy of estimation in incorporating the available knowledge on the product. In particular, the finite element results and expert belief are considered as prior knowledge. For life time prediction by finite element method, a model based on Brown–Miller law was developed for the boot seal rubber-like material.
Kinematics of a New High-Precision Three-Degree-of-Freedom Parallel Manipulator
Authors: Tahmasebi Farhad
Published: February 2007

Closed-form direct and inverse kinematics of a new three-degree-of-freedom (DOF) parallel manipulator with inextensible limbs and base-mounted actuators are presented. The manipulator has higher resolution and precision than the existing three-DOF mechanisms with extensible limbs. Since all of the manipulator actuators are base mounted, higher payload capacity, smaller actuator sizes, and lower power dissipation can be obtained. The manipulator is suitable for alignment applications where only tip, tilt, and piston motions are significant. The direct kinematics of the manipulator is reduced to solving an eighth-degree polynomial in the square of the tangent of the half-angle between one of the limbs and the base plane. Hence, there are at most 16 assembly configurations for the manipulator. In addition, it is shown that the 16 solutions are eight pairs of reflected configurations with respect to the base plane. Numerical examples for the direct and inverse kinematics of the manipulator are also presented.
Development of a Virtual Environment for Interactive Interrogation of Computational Mixing Data
Authors: Duncan Thomas J. , Vance Judy M.
Published: February 2007

Virtual reality (VR) has the potential to enable visualization of complex physical phenomena in their natural spatial scales and significantly improve the product development process. Virtual environments provide a tool for users to interact with three-dimensional models using intuitive methods in their natural spatial scales. This paper presents the implementation details of a virtual environment combining surround-screen virtual reality technology and particle tracing of massless particles to explore the benefits these tools bring to engineers seeking to understand the complex fluid behavior present in mixing processes. The implementation of interaction methods, including volume data selection using a convex hull approach, cutting plane generation, and the integration of a tablet PC as a user interface, will be presented. Design and technical details involved with the interaction methods will be discussed along with the resulting interactive virtual environment.
INVARIANTS AND SOLUTIONS OF GURZADYAN–XUE DARK ENERGY COSMOLOGICAL MODELS
Authors: KHACHATRYAN H. G.
Published: February 2007

We have derived the invariants of cosmological models with Gurzadyan–Xue (GX) dark energy, along with the solutions for any time-dependent light speed and gravitational constant. The correspondence of the invariants with the separatrices found earlier for the GX-models is shown, and hence the basis of then detected hidden symmetry is now revealed. Solutions are derived both for radiation and matter models, as well as with both components. It is interesting that, the solutions for the scale factor do not depend on the gravitational constant but only on the "time evolution" of the speed of light. GX-invariants act as efficient tools describing the models and the phases of the cosmological expansion.
QCD PHYSICS WITH ZEUS AND H1 AT HERA
Authors: BUSSEY PETER J.
Published: February 2007

A review is presented of recent results in QCD from the H1 and ZEUS experiments at HERA, emphasizing the use of higher order calculations to describe the data.
PROTON DECAY IN TERAVOLT UNIFICATION
Authors: FRAMPTON P. H.
Published: February 2007

Model building based on Abelian quiver gauge theories gives models which resemble trinification, originally proposed with yottavolt unification. However, unification occurs in the teravolt range so proton decay must be completely excluded in the scalar sector. It is straightforward to accomplish this by a discrete symmetry which is a generalized baryon number B. Unlike in trinification, this is possible because quarks and leptons acquire masses from relevant operators which appear in four-dimensional conformal symmetry breaking.
APPLYING THE METHOD OF SMALL–SHUFFLE SURROGATE DATA: TESTING FOR DYNAMICS IN FLUCTUATING DATA WITH TRENDS
Authors: NAKAMURA TOMOMICHI , SMALL MICHAEL
Published: February 2007

Recently, a new surrogate method, the Small–Shuffle (SS) surrogate method, has been proposed to investigate whether there is some kind of dynamics in irregular fluctuations, even if they are modulated by long term trends or periodicities. This situation is theoretically incompatible with the assumption underlying previously proposed surrogate methods. We apply the SS surrogate method to a variety of simulated data with known dynamics and actual time series with unknown dynamics.
ABOUT THE DERIVATION OF THE SCA ALGORITHM
Authors: ALLEFELD CARSTEN
Published: February 2007

An approach to multivariate phase synchronization analysis in the form of a Synchronization Cluster Analysis (SCA) was introduced in [Allefeld & Kurths, 2004]. A statistical model of a synchronization cluster was described, and an abbreviated instruction on how to apply this model to empirical data was given, while an implementation of the corresponding algorithm was (and is) available from the authors. In this letter, the complete details on how the data analysis algorithm is to be derived from the model are filled in.
NEUROMOTOR COORDINATION OF MULTISEGMENTAL MUSCLE DURING A CHANGE IN MOVEMENT DIRECTION
Authors: Brown J. M. M. , Wickham J.
Published: February 2007

The aim of this investigation was to determine how the CNS controlled seven segments of the human deltoid muscle during a change in the direction of shoulder joint motion. Specifically, we wished to determine how the prime mover, synergist and antagonist muscle segments of this muscle were manipulated to assume new functional roles as the direction of shoulder motion was rapidly changed from shoulder abduction to shoulder adduction. Seven bipolar surface electrodes (7 mm inter-electrode distance) were placed over the seven segments (D1–D7) of the right deltoid, in seven young (19–24yrs) male subjects, to detect changes in muscle segment activation as the subjects transitioned from a rapid shoulder-abduction to a rapid-adduction force impulse (MT = 1000 ms). For each subject, fifteen trials were recorded at an inter-trial interval of 30 seconds. Comparisons of muscle segment timing and intensity of activation were made across 6 equal time intervals between just before the peak of the abduction force impulse and the subsequent peak of the adduction force impulse. The results of this study have shown that segments of the deltoid were activated during both the shoulder abduction and shoulder adduction motor task. In addition, the pattern of muscle segment activation (timing and intensity), during the transition from shoulder abduction to shoulder adduction, was dependent upon the muscle's moment arm and line of pull in relation to the axis of shoulder joint rotation. Three distinct patterns of neuromotor activation were noted within the segments of the deltoid muscle. During abduction the agonist prime mover and synergist segments (D1–D5) were totally deactivated (< 10% MVC) as they became antagonist segments during adduction. The antagonist segment (D7), during abduction, was deactivated and then reactivated as it became a synergist segment during adduction. Finally segment D6 was shown to have a nearly continuous period of activation. The study has shown that during a transition to a new movement direction, a muscle segment's line of pull and future function in the next phase of the movement appears to determine its period and intensity of activation.
Combined effects of rosiglitazone and conjugated linoleic acid on adiposity, insulin sensitivity, and hepatic steatosis in high-fat-fed mice
Authors: Liu Li-Fen , Purushotham Aparna , Wendel Angela A. , Belury Martha A.
Published: February 2007

Dysfunctional cross talk between adipose tissue and liver tissue results in metabolic and inflammatory disorders. As an insulin sensitizer, rosiglitazone (Rosi) improves insulin resistance yet causes increased adipose mass and weight gain in mice and humans. Conjugated linoleic acid (CLA) reduces adipose mass and body weight gain but induces hepatic steatosis in mice. We examined the combined effects of Rosi and CLA on adiposity, insulin sensitivity, and hepatic steatosis in high-fat-fed male C57Bl/6 mice. CLA alone suppressed weight gain and adipose mass but caused hepatic steatosis. Addition of Rosi attenuated CLA-induced insulin resistance and dysregulation of adipocytokines. In adipose, CLA significantly suppressed lipoprotein lipase and fatty acid translocase (FAT/CD36) mRNA, suggesting inhibition of fatty acid uptake into adipose; addition of Rosi completely rescued this effect. In addition, CLA alone increased markers of macrophage infiltration, F4/80, and CD68 mRNA levels, without inducing TNF-α in epididymal adipose tissue. The ratio of Bax to Bcl2, a marker of apoptosis, was significantly increased in adipose of the CLA-alone group and was partially prevented by treatment of Rosi. Immunohistochemistry of F4/80 demonstrates a proinflammatory response induced by CLA in epididymal adipose. In the liver, CLA alone induced microsteatotic liver but surprisingly increased the rate of very-low-density lipoprotein-triglyceride production without inducing inflammatory mediator-TNF-α and markers of macrophage infiltration. These changes were accompanied by significantly increased mRNA levels of stearoyl-CoA desaturase, FAT/CD36, and fatty acid synthase. The combined administration of CLA and Rosi reduced hepatic liver triglyceride content as well as lipogenic gene expression compared with CLA alone. In summary, dietary CLA prevented weight gain in Rosi-treated mice without attenuating the beneficial effects of Rosi on insulin sensitivity. Rosi ameliorated CLA-induced lipodystrophic disorders that occurred in parallel with rescued expression of adipocytokine and adipocytes-abundant genes.