bluuebunny/crossref_metadata_2025_split huggingface dataset:
VANILLA FLAVOR EVALUATION BY SENSORY AND ELECTRONIC NOSE TECHNIQUES
Authors: HARIOM  , SHYAMALA B.N. , PRAKASH M. , BHAT K.K. 
Published: March 2006

ABSTRACT Aroma analyses using electronic nose (E‐nose) and sensory techniques with a trained panel were conducted for vanilla extracts from four samples of vanilla pods, namely, T1 (Bourbon method), T2 (Improved T1), M1 (Mexican method) and M2 (Improved M1). The E‐nose pattern matching complemented sensory threshold results, odor profiling and flavor profile results. T2 and M2 differed from the rest of the samples by showing discrimination in flavor quality between four extracts and a blank (BL). Threshold values of the extracts were in the range of 3.7 to 4.1 and 3.6 to 4.0 mg/L when prepared in water and milk mediums, respectively. The descriptive sensory profiling of the flavor of vanilla extract in different media using quantitative descriptive analysis (QDA) has indicated that milk was an optimum carrier or medium for the clear perception of characteristic vanilla attributes. T2 and M2 extracts had higher intensities of impact‐making attributes, namely, vanilla, floral and sweet notes. The intensity ratings were 8.0, 8.8 and 12.1, 11.0 for the vanilla and sweet notes of M2 and T2 extracts, respectively, when flavor profiling of vanilla extracts were prepared in milk as the medium. The odor profiling of vanilla extracts also showed similar results.
Variability of Isotope and Major Ion Chemistry in the Allequash Basin, Wisconsin
Authors: Walker John F. , Hunt Randall J. , Bullen Thomas D. , Krabbenhoft David P. , Kendall Carol 
Published: March 2006

AbstractAs part of ongoing research conducted at one of the U.S. Geological Survey's Water, Energy, and Biogeochem‐ical Budgets sites, work was undertaken to describe the spatial and temporal variability of stream and ground water isotopic composition and cation chemistry in the Trout Lake watershed, to relate the variability to the watershed flow system, and to identify the linkages of geochemical evolution and source of water in the watershed. The results are based on periodic sampling of sites at two scales along Allequash Creek, a small headwater stream in northern Wisconsin. Based on this sampling, there are distinct water isotopic and geochemical differences observed at a smaller hillslope scale and the larger Allequash Creek scale. The variability was larger than expected for this simple watershed, and is likely to be seen in more complex basins. Based on evidence from multiple isotopes and stream chemistry, the flow system arises from three main source waters (terrestrial‐, lake‐, or wetland‐derived recharge) that can be identified along any flowpath using water isotopes together with geochemical characteristics such as iron concentrations. The ground water chemistry demonstrates considerable spatial variability that depends mainly on the flow‐path length and water mobility through the aquifer. Calcium concentrations increase with increasing flowpath length, whereas strontium isotope ratios increase with increasing extent of stagnation in either the unsaturated or saturated zones as waters move from source to sink. The flowpath distribution we identify provides important constraints on the calibration of ground water flow models such as that undertaken by Pint et al. (this issue).
Flowpath Delineation and Ground Water Age, Allequash Basin, Wisconsin
Authors: Pint Christine D. , Hunt Randall J. , Anderson Mary P. 
Published: March 2006

AbstractAn analysis of ground water flowpaths to a lake and creek in northern Wisconsin shows the flow system in a geologically simple basin dominated by lakes can be surprisingly complex. Differences in source area, i.e., lakes or terrestrial, combined with the presence of intervening lakes, which may or may not capture underflowing ground water as water moves downgradient from recharge areas, contribute to a complex mix of flowpaths. The result is water of different chemistry and vastly different ages may discharge in close proximity. Flowpaths, travel times, and capture zones in the Allequash Basin in northern Wisconsin were delineated using particle tracking based on a calibrated steady‐state ground water flow model. The flowpath analysis supports the conclusions of Walker et al. (2003) who made inferences about flowpath characteristics from isotope and major ion chemistry. Simulated particle tracking agreed with Walker et al.'s measurements of water source (lake or terrestrial recharge) in the stream subsurface and also supported their assertion that ground water with a high calcium concentration in the lower basin of Allequash Lake is derived from long flowpaths. Numerical simulations show that ground water discharging in this area originates more than 5 km away in a source area located upgradient of Big Muskellunge Lake, which is upgradient of Allequash Lake. These results graphically illustrate that in settings with multiple sources of water with different age characteristics and converging flowlines (like the Allequash Basin) it may be difficult to obtain accurate estimates of ground water age by chemical analyses of ground water.
Ground Water Storage Effect on Streamflow for a Southeastern Coastal Plain Watershed
Authors: Bosch David D. , Lowrance R. Richard , Sheridan Joseph M. , Williams Randall G. 
Published: March 2006

AbstractGround water is known to substantially affect streamflow in regions where the two are interconnected. Likewise, streamflow can rapidly recharge surficial aquifers. Because of this interaction, accurate predictions of streamflow require accurate data on the relationships between streamflow and shallow aquifer conditions. Ground water levels in the surficial aquifer and streamflow were examined for a six‐year period for two small watersheds in south‐central Georgia within the Coastal Plain Physiographic region of the United States. Precipitation for the six‐year period was below average. The shallow water table was elevated during average precipitation conditions, but receded as precipitation decreased. During the three‐year period from 2000 through 2002, the riparian buffer was fully saturated approximately 40% of the time. Lower available aquifer storage was observed for late winter and early spring due to higher rainfall and lower evapotranspiration (ET). During recharge periods, which generally coincided with the period from December to March, the ground water gradient from the upland to the stream was approximately equal to the 3% land surface slope. During other times of the year, the gradient fluctuated dramatically as a response to individual precipitation events, streamflow, and focused recharge. Based on ground water discharging to the stream for 40% of the year, ground water discharge accounted for approximately 4% of the annual precipitation for the period from 2000 through 2002. Aquifer saturation, the fraction of the available aquifer storage filled by ground water, was found to have a substantial effect upon streamflow. During periods when the aquifer was fully saturated, observed storm‐generated streamflow peak rates were greater and of shorter duration. Comparison of similar magnitude events occurring in 1998 indicated that peak discharge was up to three times greater under saturated aquifer conditions than under nonsaturated conditions. Watersheds with substantial pond acreage appear to extend storm‐flow over longer durations. These data indicate the impact of aquifer and pond storage on peak and total discharge in coastal plain watersheds.
The Geochemical Evolution of Riparian Ground Water in a Forested Piedmont Catchment
Authors: Burns Douglas A. , Plummer L. Niel , McDonnell Jeffrey J. , Busenberg Eurybiades , Casile Gerolamo C. , Kendall Carol , Hooper Richard P. , Freer James E. , Peters Norman E. , Beven Keith , Schlosser Peter 
Published: March 2006

AbstractThe principal weathering reactions and their rates in riparian ground water were determined at the Panola Mountain Research Watershed (PMRW) near Atlanta, Georgia. Concentrations of major solutes were measured in ground water samples from 19 shallow wells completed in the riparian (saprolite) aquifer and in one borehole completed in granite, and the apparent age of each sample was calculated from chloroflourocarbons and tritium/helium‐3 data. Concentrations of SiO2, Na+, and Ca2+ generally increased downvalley and were highest in the borehole near the watershed outlet. Strong positive correlations were found between the concentrations of these solutes and the apparent age of ground water that was modern (zero to one year) in the headwaters, six to seven years midway down the valley, and 26 to 27 years in the borehole, located ∼500 m downstream from the headwaters. Mass‐balance modeling of chemical evolution showed that the downstream changes in ground water chemistry could be largely explained by weathering of plagioclase to kaolinite, with possible contributions from weathering of K‐feldspar, biotite, hornblende, and calcite. The in situ rates of weathering reactions were estimated by combining the ground water age dates with geochemical mass‐balance modeling results. The weathering rate was highest for plagioclase (∼6.4 μmol/L/year), but could not be easily compared with most other published results for feldspar weathering at PMRW and elsewhere because the mineral‐surface area to which ground water was exposed during geochemical evolution could not be estimated. However, a preliminary estimate of the mineral‐surface area that would have contacted the ground water to provide the observed solute concentrations suggests that the plagioclase weathering rate calculated in this study is similar to the rate calculated in a previous study at PMRW, and three to four orders of magnitude slower than those published in previous laboratory studies of feldspar weathering. An accurate model of the geochemical evolution of riparian ground water is necessary to accurately model the geochemical evolution of stream water at PMRW.
Mixing of Hillslope, River, and Alluvial Ground Waters in Lowland Floodplains
Authors: Claxton Amanda J. , Bates Paul D. , Cloke Hannah L. 
Published: March 2006

AbstractIn this paper, we develop and apply a two‐dimensional flow and transport model to simulate the mixing of variously sourced water within a fluvial floodplain during one in‐bank and one out‐of‐bank flood event. The model is applied to two 120 m long transects through the floodplain of the River Severn, Shropshire, United Kingdom, which run to the river from the hillslope bordering the floodplain. For this site, hourly piezometric, river stage, and rainfall data are used to parameterize and validate the flow component of the model. Simulation of the movement of hypothetical conservative tracers driven by these hydrodynamic conditions is then undertaken to confirm and refine an evolving conceptual model of floodplain hydrology. This is based on the bank storage concept, and extended to include the impact of hillslope contributions to the floodplain/riparian zone and the impact of out‐of‐bank inundation on subsurface flow processes. The paper demonstrates that the role of the unsaturated zone has been underestimated in our previous investigations at this site and, in addition, that there is a potentially high residence time for solutes which remain in the unsaturated zone at the end of the flood event. In general, flood events in lowland plain systems are shown to be times of great hydrological and chemical activity. Lastly, the results confirm the complexity of interactions between surface and ground water flows in lowland plain settings and highlight the need for correct treatment of both dynamic boundary conditions and unsaturated zone processes.
The Significance of Ground Water to the Accumulation of Iron and Manganese in the Sediments of Two Hydrologically Distinct Lakes in North‐Central Minnesota: A Geological Perspective
Authors: Dean Walter E. , Neff Brian P. , Rosenberry Donald O. , Winter Thomas C. , Parkhurst Renee 
Published: March 2006

AbstractWilliams and Shingobee lakes are at opposite ends of the local ground water flow system in the Shingobee River Headwaters Area (SRHA) in north‐central Minnesota. Williams Lake, situated near the highest point in the flow system, has no surface inlet or outlet, and ground water and precipitation are the only sources of water. Shingobee Lake, situated at the lowest point in the flow system, has the Shingobee River as an inlet and outlet. Ground water directly contributes an estimated one‐fourth of the water input to Shingobee Lake. The Shingobee River also receives large amounts of ground water discharge along its reach to Shingobee Lake providing a large, indirect source of ground water to the lake. Differences in nutrient concentrations reflect the residence times and nutrient supplies of these two lakes. The average phosphorus content of Shingobee Lake is about twice that of Williams Lake. Consequently, phy‐toplankton productivity in Shingobee Lake is much higher than in Williams Lake, leading to an oxygen‐deficient (<1 ppm dissolved oxygen) hypolimnion within a month after overturn in both the spring and fall. Because of the extreme reducing conditions in the hypolimnion of Shingobee Lake, high concentrations of dissolved iron and manganese are present there during summer stratification. In some years, the manganese concentration in the hypolimnion of Shingobee Lake remains high throughout the year. Precipitation of iron and manganese minerals, presumed to be X‐ray amorphous oxyhydroxides, at periods of fall and spring overturn result in concentrations of iron and manganese in surface sediments of Shingobee Lake that are seven times and 27 times higher, respectively, than can be explained by contributions of iron and manganese from detrital aluminosilicates. These findings indicate that the source and amounts of this excess iron and manganese found in the sediments are correlated to the amount of iron‐ and manganese‐rich ground water discharging to Shingobee Lake. Because iron and manganese oxyhydroxides are efficient adsorbers of phosphorus, concentrations of phosphorus are also high in the sediments of Shingobee Lake. Without this sequestration of phosphorus, the productivity of Shingobee Lake would probably be much higher.
Shallow Water Table Fluctuations in Relation to Soil Penetration Resistance
Authors: Shanley James B. , Hjerdt K. Niclas , McDonnell Jeffrey J. , Kendall Carol 
Published: March 2006

AbstractHydrologic modeling of catchments is frequently hampered by lack of information on subsurface stratigraphy and zones of preferred flow. We evaluated the usefulness of soil penetration resistance, easily measured by a dynamic cone penetrometer, together with measurements of ground water level fluctuations, as a cost‐effective means to infer subsurface flow patterns. At our field site at Sleepers River, Vermont, penetration resistance was lowest in the surfi‐cial 10 to 30 cm, then typically increased to a local maximum at 60 to 80 cm, which we interpreted as the soil/till interface. Below this depth usually lies a zone of decreased resistance in the till, giving way to either a gradual or abrupt increase in resistance toward the bedrock surface at 1 to 4.5 m depth. Penetration resistance had a weak but significant negative correlation with saturated hydraulic conductivity determined by bail tests (r2= 0.25, p < 0.05). At many wells, monthly ground water levels tended to cluster at or just above the resistant zone near the soil/till interface. Chemical and isotopic dynamics in nested wells finished above and below the resistant zone suggest that the zone may temporarily isolate the deeper ground water reservoir from meltwater inputs, which were clearly identified by low δ18O values. In ground water discharge zones, δ18O values tended to converge throughout the profile. In contrast, dissolved organic carbon (DOC) maintained a gradient of increasing concentration toward land surface, even in otherwise well‐mixed waters, reflecting its rapid release from organic horizons. Understanding the effect of soil penetration resistance on ground water behavior may be useful in future catchment modeling efforts.
Estimating Ground Water Yield in Small Research Basins
Authors: Verry Elon S. 
Published: March 2006

AbstractAn analysis of ground water recharge in 32 small research watersheds shows the average flow of ground water out of the watershed (deep seepage) is 45% of streamflow and ranges from 8 to 350 mm/year when apportioned over the watershed area. It is time to meld ground water and small watershed science. The use of well networks and the evaluation of ground water well hydrographs or the use of ground water models to estimate deep seepage from small research basins is highly recommended. Future investigators are now armed with better tools necessary to estimate all the water and nutrients and have no need to quietly assume deep seepage is zero.
Ecological Consequences of Ground Water Discharge to Delaware Bay, United States
Authors: Miller Douglas C. , Ullman William J. 
Published: March 2006

AbstractSubmarine ground water discharge to the ocean has the potential to create estuarine conditions near the point of discharge, thereby dramatically altering local benthic habitats and ecology. Aerial thermal infrared imaging along the southwestern margin of Delaware Bay indicated abundant discharge at Cape Henlopen, Delaware, adjacent to the Atlantic Ocean. On the sandflat there, we have documented low salinity in sedimentary pore waters within 20 m of the beachface that are associated with dense assemblages (in thousands per square meter) of a deep, burrow‐dwelling polychaete worm, Marenzelleria viridis, otherwise regarded as a species characteristic of fresher, oligohaline conditions. Where present, M. viridis is a numerical and biomass dominant in a benthic community strikingly different from that in nearby nonseep locations. At Cape Henlopen, the ecological role of the ground water discharge appears to be a multifaceted one. Seeps are localized regions of significantly reduced salinity, stabilized temperature, increased nutrient flux, high microalgal abundance, and enhanced sediment stability. M. viridis feeds on sediment diatoms and may provide an important trophic linkage between microalgal growth fueled by nutrients associated with the discharging ground water and worm‐feeding predators such as bottom fish or shorebirds common on the Cape Henlopen sandflat. Calculations based on our sampling suggest that nutrients supplied by the ground water substantially exceed what is needed to support benthic biomass and productivity estimated for this site.
Tidal Effects on Ground Water Discharge Through a Sandy Marine Beach
Authors: Urish Daniel W. , McKenna Thomas E. 
Published: March 2006

AbstractTidal fluctuations along the salt water boundary of a sandy beach affect the magnitude, location, timing, and salinity of both subaerial and submarine ground water discharge. Detailed studies of shoreline discharge from an unconfined aquifer at two sites in an embayment on the Cape Cod, Massachusetts, coastline provide insight into the highly dynamic spatial and temporal nature of discharge along sandy beaches affected by the tide. The constantly moving tidal boundary over a sloping beach results in a shoreline‐perpendicular discharge zone of 10 to 20 m, with ∼35% to 55% of the discharge being submarine discharge. The distribution of fresh ground water through a beach face varies greatly, depending primarily on the tidal cycle and range, the heterogeneous characteristics of the beach sediments, and the beach geometry. The estimated relative volume of discharge varies temporally with tidal fluctuations, with the greatest discharge occurring during early to mid ebbing tide and location of greatest estimated discharge moving seaward during ebbing tide. This is determined using net hydraulic head calculations in monitoring wells set in a shoreline‐perpendicular transect in the beach. The salinity of discharge varies temporally from near fresh water values of 1 part per thousand (ppt) to near coastal salt water values of 30 ppt, being saltiest at the start of discharge as the tide ebbs and freshest during a low tide period of ∼2 h. Of the discharge volume, ∼65% to 85% is estimated to be from salt water that infiltrates during high tide episodes. This study highlights the complexity of the dynamic coastal ground water discharge phenomenon and provides insight into the hydraulic mechanisms involved. While there is a general pattern to sandy beach discharge, comparison of results from beaches studied at Cape Cod indicates that the temporal and spatial details of the discharge is very site‐specific.
Submarine Ground Water Discharge and Salt Penetration Across the Sea Floor
Authors: Bokuniewicz Henry , Pollock Meagen , Blum John , Wilson Robert 
Published: March 2006

AbstractFresh ground water entering an estuary can be mixed with salt water in the upper few decimeters of the sediment. As a result, net measured discharge rates at the sediment‐water interface can be equal to the volume discharge of fresh ground water, although the salinity of the escaping water is high. Benthic chambers, vented to a collection bag, were used to measure specific volume discharge rates over ∼5 cm/day near the shoreline of a wide, shallow lagoon—Great South Bay, New York—situated at the surface of a coastal plain aquifer. These rates decreased to 1.5 cm/day at a distance of 100 m from shore. Although the flow rate is expected to be inversely correlated to the tidal water level elevation, and has been shown to be so modulated at other sites, no consistent variation in discharge with tidal phase was found; the tidal range (25 cm) may have been too small to have a measurable effect. Water collected at a particular location freshened over time from 30 to 23 ppt in 12 hours. Piezometers recorded vertical hydraulic gradients (at ambient salinity) between 0.08 and 0.02 in the upper meter of the sediment and the vertical hydraulic conductivity was measured by a falling head test to be between 1 and 20 m/day. The discharge rates calculated by Darcy's law decreased offshore from dozens of cm/day within 10 m of shore to 1.8 cm/day at a distance of 100 m, consistent with measured seepage rates. Conductivity measurements imply that pore water salinity decreases from ambient bay values at the sea floor to near fresh water values at a depth of 0.6 m into the sediment. The vertical downward dispersion coefficient for salt was estimated to be 0.02 m2/day. This could be due to the superposition of water wave‐induced dispersion in the sediment with gravitational convection (salt fingering).
Tidal Load and Salt Water Influences on Submarine Ground Water Discharge
Authors: Paulsen Ronald J. , O'Rourke Daniel , Smith Christopher F. , Wong Teng‐Fong 
Published: March 2006

AbstractField measurements were conducted to characterize the influences of salt water and tidal loading on submarine ground water discharge (SGD) into West Neck Bay on Shelter Island, New York. SGD was continuously recorded at three sites using an ultrasonic ground water seepage meter, and the spatial extents of the terrestrially derived SGD and the salt water/fresh water mixing zone were inferred from electrical conductivity profiling. While SGD increases with increasing hydraulic gradient in the far field of the coastal aquifer, shorter temporal variations of SGD were inversely correlated with tidal stage. SGD and hydraulic heads in the onshore unconfined aquifer near the coast responded asymmetrically to tidal loading, with discharge and head increasing faster than decreasing. A time lag of ∼1 h was observed between the tidal load and responses in onshore head and SGD. This lag represents a manifestation of the travel time required for tidal influences to propagate landward before the hydraulic gradient adjusts and influences seepage. The spatial extent of the fresh water component of SGD determined by electrical conductivity profiles, seepage velocity, and the time lag between tide and SGD amplitudes are in reasonable agreement with analytic estimates.