scholarly journals Quantifying the Relation Between Electrical Conductivity and Salt Concentration for Dilution Gauging Via Dry Salt Injection

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Mark Richardson ◽  
Gabe Sentlinger ◽  
R.D. (Dan) Moore ◽  
André Zimmermann
Keyword(s):  
Electrical Conductivity ◽  
Salt Concentration ◽  
Stream Water ◽  
Ionic Composition ◽  
Calibration Procedure ◽  
Calibration Factor ◽  
Measured Temperature ◽  
Discharge Measurement ◽  
Background Temperature ◽  
Analytical Correction

Salt dilution is a popular approach used for discharge measurement. This research focused on the procedure for determining the calibration factor (CFT) that is used to convert measured temperature corrected electrical conductivity to salt concentration for injection using dry salt. It is important to document the uncertainty in CFT because it contributes directly to uncertainty in the calculated discharge. Based on laboratory trials, it was found that the calibration should be performed as close to in situ stream temperature as possible to minimize errors. The discharge measurement and calibration procedure should be performed with the same probe to minimize uncertainty. Distilled water can be used instead of stream water for a calibration solution if an analytical correction is applied to account for differences in ionic composition of the water. The calibration factor can be determined with an uncertainty of less than ± 1% under “best-case” conditions, and the uncertainty may be as high as ± 4% under less favourable conditions. If calibration is not performed, CFT can be estimated from the relation between CFT and background temperature-corrected electrical conductivity (ECBG) with an uncertainty of about ± 2%, or estimated as a set value of 0.486 mg·cm·μS-1·L-1 with an uncertainty of about ± 2.8% for a properly calibrated probe. More testing should focus on streams with ECBG > 500 μS·cm-1, which were not well represented in this study.

Shallow Magnetic Induction Measurements for Delineating Near-Surface Hot Groundwater Sources in Alaskan Geothermal Areas

1983 ◽  
Vol 105 (2) ◽  
pp. 156-161 ◽  
Author(s):  
T. E. Osterkamp ◽  
K. Kawasaki ◽  
J. P. Gosink
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Induction ◽  
Hot Springs ◽  
Measured Temperature ◽  
Conductivity Data ◽  
Induction Method ◽  
Near Surface ◽  
Saline Groundwater ◽  
Geophysical Surveys ◽  
Conductivity Anomalies

Variations in the electrical conductivity of a soil and water system with temperature and salt concentration suggest that a soil containing hot and/or saline groundwater may be expected to have a higher conductivity compared to a cooler and/or less saline system. Temperature and conductivity surveys were carried out at Pilgrim Springs, on the Seward Peninsula, and at Chena Hot Springs, near Fairbanks, to test the use of a magnetic induction method (which measures electrical conductivity) for delineating near-surface hot groundwater sources in geothermal areas surrounded by permafrost. Comparison of the temperature data and conductivity data from these surveys demonstrates that the conductivity anomalies, as measured by the magnetic induction method, can be used to define the precise location of hot groundwater sources in these geothermal areas with the higher temperatures correlating with higher values of conductivity. Magnetic induction measurements of conductivity can also be used to define the lateral extent of the thawed geothermal areas (used for calculating the stored energy) in permafrost terrain. The utility of these magnetic induction measurements of conductivity for reconnaissance geophysical surveys of geothermal areas is that a much greater density of data can be obtained in a shorter time in comparison with shallow temperature measurements. In addition, it is simpler, cheaper and easier (physically) to obtain the data. While conductivity anomalies can result from other than hot and/or saline groundwater, these conductivity data, when coupled with a few measured temperature profiles and groundwater samples, should result in reliable reconnaissance level geophysical surveys in Alaskan geothermal areas.

Electrical Conductivity of Agricultural Drainage Water in Iowa

2017 ◽  
Vol 33 (3) ◽  
pp. 369-378 ◽  
Author(s):  
Brett A Zimmerman ◽  
Amy L Kaleita
Keyword(s):  
Electrical Conductivity ◽  
Environmental Conditions ◽  
Major Ions ◽  
Ionic Composition ◽  
Field Investigation ◽  
Drainage Water ◽  
Specific Electrical Conductivity ◽  
Agricultural Drainage ◽  
Bulk Electrical Conductivity ◽  
Drainage Waters

Abstract. Assessing the effectiveness of management strategies to reduce agricultural nutrient efflux is hampered by the lack of affordable, continuous monitoring systems. Generalized water quality monitoring is possible using electrical conductivity. However environmental conditions can influence the ionic ratios, resulting in misinterpretations of established electrical conductivity and ionic composition relationships. Here we characterize specific electrical conductivity (k25) of agricultural drainage waters to define these environmental conditions and dissolved constituents that contribute to k25. A field investigation revealed that the magnitude of measured k25 varied from 370 to 760 µS cm-1. Statistical analysis indicated that variability in k25 was not correlated with drainage water pH, temperature, nor flow rate. While k25 was not significantly different among drainage waters from growing and post-growing season, significant results were observed for different cropping systems. Soybean plots in rotation with corn had significantly lower conductivities than those of corn plots in rotation with soybeans, continuous corn plots, and prairie plots. In addition to evaluating k25 variability, regression analysis was used to estimate the concentration of major ions in solution from measured k25. Regression results indicated that HCO3-, Ca2+, NO3-, Mg2+, Cl-, Na2+, SO42- were the major drainage constituents contributing to the bulk electrical conductivity. Calculated ionic molal conductivities of these analytes suggests that HCO3-, Ca2+, NO3-, and Mg2+ account for approximately 97% of the bulk electrical conductivity. Keywords: Electrical conductivity, Salinity, Subsurface drainage, Total dissolved solids.

scholarly journals Karst hydrogeology of Lamprechtsofen (Leoganger Steinberge, Salzburg)

2019 ◽  
Vol 112 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Katharina Gröbner ◽  
Wolfgang Gadermayr ◽  
Giorgio Höfer-Öllinger ◽  
Harald Huemer ◽  
Christoph Spötl
Keyword(s):  
Electrical Conductivity ◽  
Water Temperature ◽  
Water Level ◽  
Stream Water ◽  
Tracer Tests ◽  
Karst Water ◽  
Stream Flows ◽  
Surface Precipitation ◽  
Mineralized Water ◽  
Show Cave

AbstractThe Leoganger Steinberge are a heavily karstified massif largely composed of Dachstein dolomite and limestone hosting the deepest through-trip cave in the world, Lamprechtsofen, whose frontal parts are developed as a show cave. Many parts of this 60 km-long and 1724 m-deep system are hydrologically active. 1.5 km behind the lower cave entrance Grüntopf stream and Kneippklamm stream merge to form the main cave stream. Another underground stream, Stainerhallen stream, flows through the eponymous hall of the show cave. Since 2007 water temperature, electrical conductivity and water level have been monitored in the Grüntopf and Kneippklamm stream. Water temperature and water level in the Stainerhallen and main cave stream have been measured since 2016.The long-term dataset (2013–2017) shows that the water temperature of the cave streams (Grüntopf stream: 3.7–5.2°C; Kneippklamm stream: 5.1–5.9°C) is largely invariant, but the electrical conductivity varies strongly (Grüntopf stream: 107–210 µS/cm; Kneippklamm stream: 131–248 µS/cm) in response to snowmelt and precipitation events. The event water of the Kneippklamm stream is characterized by a low electrical conductivity and is then followed by slightly warmer and higher mineralized water derived from the phreatic zone. This dual flow pattern also explains the asymmetrical changes of the water level during snowmelt: the fast event water flows directly through vadose pathways to the measurement site, whereas the hydraulic (phreatic) response is delayed. The Grüntopf stream reacts to precipitation and snowmelt events by changes in the karst-water table, which can be explained by a piston flow-model. The Kneippklamm stream reveals evidence of a lifter system.The altitude of the catchments was calculated using δ18O values of water samples from the underground streams and from surface precipitation. The Grüntopf stream shows the highest mean catchment (2280 m a.s.l.), which is in agreement with its daily fluctuations of the water level until August caused by long-lasting snowmelt. The Stainerhallen stream has the lowest catchment (average 1400 m a.s.l.). The catchments of the other two streams are at intermediate elevations (1770–1920 m a.s.l.). The integration of the catchment analyses and observations from tracer tests conducted in the 1970s showed that the latter reflected only one aspect of the karst water regime in this massif. During times of high recharge the water level rises, new flow paths are activated and the karst watershed shifts.

Linking hydrological response to forest dynamics in Mediterranean areas: a new experimental catchment in the Apennine Mountains, Tuscany, Italy

2020 ◽  
Author(s):  
Daniele Penna ◽  
Marco Borga ◽  
Elena Bresci ◽  
Giulio Castelli ◽  
Pietro Castellucci ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Forest Dynamics ◽  
Stream Water ◽  
Water Levels ◽  
Mean Annual Precipitation ◽  
Hydrological Response ◽  
Canopy Interception ◽  
Near Surface ◽  
Mediterranean Areas

<p>The bi-directional ecohydrological interactions between forest dynamics and catchment hydrological response in Mediterranean forest ecosystems remain poorly conceptualized. Understanding the effect of tree water uptake and transpiration patterns on how catchments store and release water and, vice versa, on how catchment water availability affects tree physiological response is of paramount importance for forest and water resource management. This is crucial in the light of the predicted prolonged drought periods that will exacerbate the dry summer spells that characterize Mediterranean areas. In order to address these pressing issues, a new experimental mountain forested catchment for interdisciplinary ecohydrological research has been recently implemented in the Tuscan Apennines (Italy).</p><p> </p><p>The catchment size is 2 km<sup>2</sup> and elevation ranges from 650 to 1280 m a.s.l.. Forest covers more than 95% of the area, and the main tree species are beech and oak trees, with a much smaller proportion of conifers. Mean annual precipitation is around 1180 mm. Instrument installation is currently in progress and supported by two research projects (run in parallel in Italy and Luxembourg). By spring 2020, the catchment is expected to host the following equipment: one weather station plus one additional rain gauge, including a rainfall collector for isotope analysis; four stream gauges at different spatial scales (from a 2-ha headwater subcatchment to the catchment outlet) including continuous electrical conductivity measurements; three groundwater wells (ranging from 2 to 5 m depth) equipped with water level and electrical conductivity loggers; a network of soil moisture sensors at different depths; stemflow collectors; rain totalizers for manual throughfall measurements; a network of innovative multi-parametric sensors mounted on individual beech trees for continuous measurement (logging to cloud) of physiological and micro-meteorological parameters (sap flow, stem radial growth, canopy light transmission, stem wood temperature and humidity, 3D position over time, and air temperature and relative humidity).</p><p> </p><p>Preliminary data collected in 2019 show a marked seasonality of stream runoff, with low runoff coefficients in summer (<0.1), consistent with the high drainage of forested soils and large evapotranspiration fluxes. Stream electrical conductivity values increase from upstream to downstream sections, showing a consistent spatial variability among seasons and suggesting an increasingly relevance of subsurface flow for sustaining baseflow. Marked diel fluctuations in stream water levels during sunny summer days suggest a dominant control of tree transpiration on streamflow. Near-surface soil moisture spatial patterns at the hillslope scale show strong temporal stability. Future experimental activities will assess water pools used by beech trees along a hillslope. Planned tools and research include water stable isotopes, seasonal variations in canopy interception, stemflow, and throughfall as well as the spatio-temporal variability of soil moisture patterns at the plot, hillslope, and catchment scale.</p>

Electrical Conductivity of Cabbage and Daikon Radish as Affected by Electrical Voltage, Frequency, Salt Concentration and Temperature

2015 ◽  
Vol 40 (1) ◽  
pp. e12315
Author(s):  
Ann-Julie Duguay ◽  
Hosahalli S. Ramaswamy ◽  
Mohammad Reza Zareifard ◽  
Songming Zhu ◽  
Stefan Grabowski ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Salt Concentration ◽  
Electrical Voltage ◽  
Voltage Frequency

scholarly journals The effect of heating factors on the properties of heat-induced surimi gel under ohmic heating

2021 ◽  
Vol 13 (2) ◽  
pp. 32-42
Author(s):  
Van Nguyen
Keyword(s):  
Electrical Conductivity ◽  
Heating Rate ◽  
Salt Concentration ◽  
Ohmic Heating ◽  
Heating Time ◽  
Holding Time ◽  
Water Bath ◽  
Heating Rates ◽  
Fast Heating ◽  
Water Bath Heating

Ohmic heating (OH) is a method that heat is generated within the food due to its electrical resistance, resulting in a relatively linear heating rate and uniform temperature distribution. Because surimi-based paste contains water and salts, the conductivity is sufficiently good for the ohmic effect. Gelation induced by OH greatly depends on heating conditions such as heating speed, heating time, or electrical conductivity. However, the detailed information obtained is quite limited. Therefore, in order to clarify how ohmic heating affects the physical properties of surimi gel under OH, gels from croaker surimi (SA grade) were obtained using different heating conditions (heating speed, heating time, or salt concentration - electrical conductivity). Furthermore, the gels heated by ohmic heating were compared with the gel obtained by conventional water-bath heating. The results showed that, at the same heating rates, higher salt concentration generated better surimi gels for croaker surimi. Gels cooked ohmically at a slow heating rate performed significantly better than those cooked at a fast heating rate or heated conventionally in a water bath. There was little discernible difference in protein pattern between gels heated by OH and conventional water bath heating at fast heating rates with two different salt concentrations. The results also indicated that holding time at target temperature showed no effect on the gel. These results suggested that the properties of heat-induced surimi gels by OH are affected by not only heating speed but also holding time at maximum temperature and salt content.

Experimental Measurement of Thermophysical Properties of Alumina- MWCNTs/Salt–Water Hybrid Nanofluids

2020 ◽  
Vol 16 (5) ◽  
pp. 734-747 ◽  
Author(s):  
Amir Hossein Sharifi ◽  
Iman Zahmatkesh ◽  
Fatemeh F. Bamoharram ◽  
Amir Hossein Shokouhi Tabrizi ◽  
Safieh Fazel Razavi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Salt Concentration ◽  
Thermophysical Properties ◽  
Base Fluid ◽  
Volume Fraction ◽  
Ph Value ◽  
Nanoparticle Volume Fraction ◽  
Optimal Conditions ◽  
Hybrid Nanofluids

Background: Hybrid nanofluids are considered as an extension of conventional nanofluids which are prepared through suspending two or more nanoparticles in the base fluids. Previous studies on hybrid nanofluids have measured their thermal conductivity overlooking other thermophysical properties such as viscosity and electrical conductivity. Objective: An experimental investigation is undertaken to measure thermal conductivity, viscosity, and electrical conductivity of a hybrid nanofluid prepared through dispersing alumina nanoparticles and multiwall carbon nanotubes in saltwater. These properties are the main important factors that must be assessed before performance analysis for industrial applications. Methods: The experimental data were collected for different values of the nanoparticle volume fraction, temperature, salt concentration, and pH value. Attention was paid to explore the consequences of these parameters on the nanofluid’s properties and to find optimal conditions to achieve the highest value of the thermal conductivity and the lowest values of the electrical conductivity and the viscosity. Results: The results demonstrate that although the impacts of the pH value and the nanoparticle volume fraction on the nanofluid’s thermophysical properties are not monotonic, optimal conditions for each of the properties are reachable. It is found that the inclusion of the salt in the base fluid may not change the thermal conductivity noticeably. However, a considerable reduction in the viscosity and substantial elevation in the electrical conductivity occur with an increase in the salt concentration. Conclusion: With the addition of salt to a base fluid, the thermophysical properties of a nanofluid can be controlled.

How do concentration-discharge relations vary among rainfall-runoff events? An analysis for the Ressi experimental catchment (Italian pre-Alps)

2021 ◽  
Author(s):  
Giulia Zuecco ◽  
Chiara Marchina ◽  
Ylenia Gelmini ◽  
Anam Amin ◽  
Ilja van Meerveld ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Stable Isotopes ◽  
Temporal Dynamics ◽  
Major Ions ◽  
Stream Water ◽  
High Temporal Resolution ◽  
Runoff Coefficient ◽  
Rainfall Runoff ◽  
Antecedent Soil Moisture ◽  
Runoff Events

<p>Understanding discharge and solute responses is pivotal for water resources management and pollution mitigation measures. The few studies that have analysed concentration-discharge relations using high temporal resolution tracer data collected during rainfall-runoff events have shown that these relations may vary for different events and depend on season, event characteristics or antecedent wetness conditions. </p><p>In this study, we used hydrometric and tracer data (stable isotopes, major ions and electrical conductivity (EC)) to i) compare the concentration-discharge relations for different tracers, ii) characterize the hysteretic relations between discharge and tracer concentrations at the event timescale, and iii) determine whether the changes in hysteresis can be explained by event characteristics.</p><p>Data collection was carried out in the Ressi catchment, a 2-ha forested watershed in the Italian pre-Alps. The catchment is characterized by high seasonality in runoff response, due to the seasonality in rainfall (high in fall) and evapotranspiration (high in summer). Discharge and rainfall have been measured continuously since August 2012. Stream water, precipitation, shallow groundwater and soil water samples were collected for tracer analyses during 20 rainfall-runoff events between September 2015 and August 2018. All samples were analyzed for EC, isotopic composition (<sup>2</sup>H and <sup>18</sup>O) and major ion concentrations. To investigate the possible controls on concentration-discharge relations, we determined the main characteristics (e.g., total event rainfall, rainfall intensities, antecedent soil moisture and depth to water table, runoff coefficient) for each selected rainfall-runoff event.</p><p>The EC, calcium, magnesium, sodium and sulfate concentrations in stream water decreased during rainfall events, due to the dilution by rain water. The concentration-discharge relations for these tracers with a dilution behavior were stronger and more significant than for the tracers that were mobilized during the event. Interestingly, nitrate, potassium and chloride, concentrations sometimes increased at the onset of events, likely due to a rapid flushing of solutes from the dry parts of the stream channel and the riparian area, and then decreased during the event. These temporal dynamics in solute concentrations resulted in different hysteretic relations with discharge. Clockwise loops (i.e., discharge peaked later than the tracer concentrations) were common for the isotopes, chloride and potassium, whereas anti-clockwise hysteresis loops were more typical for EC, magnesium, calcium, sulfate, sodium and nitrate. A preliminary correlation analysis suggests that event characteristics alone cannot explain the changes in hysteresis, except for the hysteresis area for the relations between discharge and calcium concentration that depends on the magnitude of the rainfall event (i.e., the larger the rainfall amount and the runoff coefficient, the smaller the hysteresis loop). </p><p>These results highlight the importance of the first flush and indicate that runoff processes and solute sources can change when the catchment becomes wetter and connectivity of the hillslopes to the stream increases.</p><p> </p><p>Keywords: concentration-discharge relation; major ions; electrical conductivity; stable isotopes; hysteresis; forested catchment.</p>

scholarly journals Effect of Premelting on Conductivity of DNA-Lipid Films

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
A. Yu. Kasumov ◽  
S. Nakamae ◽  
M. Cazayous ◽  
T. Kawasaki ◽  
Y. Okahata
Keyword(s):  
Molecular Structure ◽  
Electrical Conductivity ◽  
Raman Spectroscopy ◽  
Measured Temperature ◽  
Dna Denaturation ◽  
Temperature Dependent ◽  
Cast Film ◽  
Lipid Films

We have measured temperature-dependent (between 20 and80∘C) electrical conductivity and molecular structure (Raman spectroscopy) of DNA-lipid cast film. Our findings show that the conductivity is strongly influenced by premelting effects in the molecular structure starting near physiological temperatures (∼40∘C), prior to the global DNA denaturation.

scholarly journals Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment

2017 ◽  
Vol 21 (1) ◽  
pp. 23-41 ◽  
Author(s):  
Daniele Penna ◽  
Michael Engel ◽  
Giacomo Bertoldi ◽  
Francesco Comiti
Keyword(s):  
Electrical Conductivity ◽  
Stream Water ◽  
Shallow Groundwater ◽  
Early Summer ◽  
Main Stream ◽  
Environmental Tracers ◽  
Spatial And Temporal Patterns ◽  
Glacier Melt ◽  
Streamflow Response ◽  
Stable Isotopes Of Water

Abstract. Multiple water sources and the physiographic heterogeneity of glacierized catchments hamper a complete conceptualization of runoff response to meltwater dynamics. In this study, we used environmental tracers (stable isotopes of water and electrical conductivity) to obtain new insight into the hydrology of glacierized catchments, using the Saldur River catchment, Italian Alps, as a pilot site. We analysed the controls on the spatial and temporal patterns of the tracer signature in the main stream, its selected tributaries, shallow groundwater, snowmelt and glacier melt over a 3-year period. We found that stream water electrical conductivity and isotopic composition showed consistent patterns in snowmelt-dominated periods, whereas the streamflow contribution of glacier melt altered the correlations between the two tracers. By applying two- and three-component mixing models, we quantified the seasonally variable proportion of groundwater, snowmelt and glacier melt at different locations along the stream. We provided four model scenarios based on different tracer signatures of the end-members; the highest contributions of snowmelt to streamflow occurred in late spring–early summer and ranged between 70 and 79 %, according to different scenarios, whereas the largest inputs by glacier melt were observed in mid-summer, and ranged between 57 and 69 %. In addition to the identification of the main sources of uncertainty, we demonstrated how a careful sampling design is critical in order to avoid underestimation of the meltwater component in streamflow. The results of this study supported the development of a conceptual model of streamflow response to meltwater dynamics in the Saldur catchment, which is likely valid for other glacierized catchments worldwide.

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