Threshold Detection Values of Potential Fish Tainting Substances from Oil Sands Wastewaters

1988 ◽  
Vol 20 (8-9) ◽  
pp. 19-25 ◽  
Author(s):  
C. G. Jardine ◽  
Steve E. Hrudey
Keyword(s):  
Oil Sands ◽  
Detection Threshold ◽  
Threshold Values ◽  
Sensory Panel ◽  
Athabasca River ◽  
Threshold Detection ◽  
Fish Flesh ◽  
River Fishery ◽  
Taste Detection

Chemical compounds associated with oil sands extraction and upgrading operations have been implicated in the tainting of the Athabasca River fishery, a commercial and subsistence fishery for local natives. Selected contaminants found in oil sands wastewaters, and judged to be candidate tainting compounds, were spiked in walleye flesh and subjected to screening odour and taste detection by a trained sensory panel. Twelve compounds were screened and 8 were pursued for determination of detection thresholds based upon 3 separate sessions with a minimum of 9 panelists. Taint detection threshold values ranging from 0.09 mg/kg for benzothiophene to 12.2 mg/kg for 2,6-dimethylnaphthalene were established. These values will assist in determining the significance of analytically determined concentrations of these compounds in fish flesh.

Abstract 18991: Salt Taste Detection and Recognition Thresholds - Reliability of a Rapid Sensory Analysis Method

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jean-François Giguère ◽  
Maria-Cecilia Gallani ◽  
Michel Doré ◽  
Alexandra Proulx Bellhumeur
Keyword(s):  
Sensory Analysis ◽  
Salt Intake ◽  
Detection Threshold ◽  
Temporal Stability ◽  
Taste Sensitivity ◽  
Analysis Method ◽  
Minimum Concentration ◽  
Salt Taste ◽  
Taste Detection

Introduction: Excessive sodium intake is clearly and independently associated with hypertension and cardiovascular diseases. The salt taste sensitivity is closely related to hedonic aspects of nutrition, and this is an important individual factor contributing to the nutritional behavior of salt intake. Hypothesis: The purpose of this study was to evaluate the reliability of an adapted-sensory analysis method for rapid determination of salt taste Detection Threshold (DT - the minimum concentration necessary to detect the stimulus) and Recognition Threshold (RT - the minimum concentration necessary to recognize the salty stimulus). Methods: The temporal stability of a rapid sensory analysis based on the 3-alternative forced-choice (3-AFC) method (ASTM E679) was tested with 30 adult volunteers. DT and RT for salt were determined using a 15 series of ascending concentrations of salt (from 1 to 290 mM; 1,5-fold steps). Intraclass correlation coefficient (ICC) was used to test the agreement between the results of the test-retest (1-week interval). For the analysis, the threshold values were log-transformed. Results: The average time of the trial per participant was 16.7 minutes. Standard deviation on log-transformed DT and RT values quite were variable among subjects. Means for both DT and RT were lower in the retest: 2,99 mM (test) vs. 2,41 mM (retest) for DT; and 19,04 mM (test) vs. 13,76 mM (retest) for RT. However, the test-retest results for both thresholds were reasonably in agreement, as confirmed by the ICCs observed: 0.599 (CI95%; 0,157 - 0,809) and 0.783 (CI95%; 0,545 - 0,897) for DT and RT, respectively. Conclusions: The sensory analysis method used in this study exhibited evidence of temporal stability, thus of a reliable measure. This observation and the fact of being fast and simple to perform for both experimenter and participant, reinforce its suitability for the determination of salt taste thresholds in studies involving large numbers of subjects. Linking between taste sensitivity to salt consumption and some clinical characteristics such as obesity and visceral fat, may help to understand the mutual influence of these variables, and suggest appropriate interventions to reduce salt intake among individuals at higher cardiovascular risk.

Characterizing Response Variability and Method Uncertainty in Odour Perception Research

1999 ◽  
Vol 40 (6) ◽  
pp. 99-105
Author(s):  
Cynthia G. Jardine ◽  
Steve E. Hrudey
Keyword(s):  
Oil Sands ◽  
Detection Method ◽  
Response Variability ◽  
Fish Flesh ◽  
Odour Perception

Data previously collected to determine odour thresholds in fish flesh for individual contaminants identified as possible fish tainting substances from oil sands wastewaters were reanalyzed to determine both the variability in response for an 11 member panel and the range of uncertainty for the detection method. Results are presented for 8 compounds: naphthalene, 1-methylnaphthalene, 2,6-dimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1.4-dimethylbenzene, benzothiophene, dibenzothiophene and 2,5-dimethylphenol. These results demonstrate that substantial variability was present in responses from a group of only 11 panelists who were selected for their sensitivity and consistency, while method uncertainty was tolerably narrow.

Use of Gas Meters for Determination of Pay Strata in Oil Sands

1925 ◽  
Vol G-25 (01) ◽  
pp. 183-195 ◽  
Author(s):  
C.V. Millikan
Keyword(s):  
Oil Sands

scholarly journals Determination of a long-term optimal irrigation strategy for dry beans in Parana State, Brazil

1997 ◽  
Vol 54 (spe) ◽  
pp. 155-164 ◽  
Author(s):  
R.T. de Faria ◽  
M.V. Folegatti ◽  
J.A. Frizzone ◽  
A.M. Saad
Keyword(s):  
Management Strategy ◽  
Irrigation Management ◽  
Growth Conditions ◽  
Threshold Values ◽  
Dry Beans ◽  
Irrigation Strategy ◽  
Product Price ◽  
Net Return

The economical benefits of different irrigation strategies were assessed by long term simulation (20 years) for dry beans in Paraná, Brazil. The model BEANGRO was used to simulate crop yield and irrigation requirements assuming eight levels of irrigation threshold (20 to 90% of the remaining soil available water in steps of 10%), in addition to a level considering no irrigation. Net return was the objective function to select the optimum irrigation management strategy, assuming fixed and stochastic distributions of historical product price. The results showed that yield was significantly increased by irrigation despite a high variability for all the simulation strategies, due to variations on growth conditions over the years. Although the net return was highly variable, it was positive in 75% of the years for all strategies with threshold values higher than 30%. The strategy of irrigating the crop before the soil reaches 60% AW provided the maximum economical benefits. The high profit using this improved strategy justifies the practice of irrigation for beans in Paraná.

scholarly journals Streamflow input to Lake Athabasca, Canada

2013 ◽  
Vol 17 (5) ◽  
pp. 1681-1691 ◽  
Author(s):  
K. Rasouli ◽  
M. A. Hernández-Henríquez ◽  
S. J. Déry
Keyword(s):  
Oil Sands ◽  
Multiple Stressors ◽  
Sediment Cores ◽  
Lake Basin ◽  
Ramsar Convention ◽  
Athabasca River ◽  
Oil Reserves ◽  
Mk Test ◽  
Streamflow Variability ◽  
Shift Detection

Abstract. The Lake Athabasca drainage area in northern Canada encompasses ecologically rich and sensitive ecosystems, vast forests, glacier-clad mountains, and abundant oil reserves in the form of oil sands. The basin includes the Peace–Athabasca Delta, recognized internationally by UNESCO and the Ramsar Convention as a biologically rich inland delta and wetland that are now under increasing pressure from multiple stressors. In this study, streamflow variability and trends for rivers feeding Lake Athabasca are investigated over the last half century. Hydrological regimes and trends are established using a robust regime shift detection method and the Mann–Kendall (MK) test, respectively. Results show that the Athabasca River, which is the main contributor to the total lake inflow, experienced marked declines in recent decades impacting lake levels and its ecosystem. From 1960 to 2010 there was a significant reduction in lake inflow and a significant recession in the Lake Athabasca level. Our trend analysis corroborates a previous study using proxy data obtained from nearby sediment cores suggesting that the lake level may drop 2 to 3 m by 2100. The lake recession may threaten the flora and fauna of the Athabasca Lake basin and negatively impact the ecological cycle of an inland freshwater delta and wetland of global importance.

Determination of the Physical Properties of Oil Sands Components using Scanning Probe Microscopy

2015 ◽  
Vol 1754 ◽  
pp. 69-74
Author(s):  
Ravi Gaikwad ◽  
Tinu Abraham ◽  
Aharnish Hande ◽  
Fatemeh Bakhtiari ◽  
Siddhartha Das ◽  
...  
Keyword(s):  
Oil Sands ◽  
Structural Changes ◽  
Rational Approach ◽  
Kelvin Probe ◽  
Scanning Calorimetry ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTAtomic force microscopy is employed to study the structural changes in the morphology and physical characteristics of asphaltene aggregates as a function of temperature. The exotic fractal structure obtained by evaporation-driven asphaltene aggregates shows an interesting dynamics for a large range of temperatures from 25°C to 80°C. The changes in the topography, surface potential and adhesion are unnoticeable until 70°C. However, a significant change in the dynamics and material properties is displayed in the range of 70°C - 80°C, during which the aspahltene aggregates acquire ‘liquid-like’ mobility and fuse together. This behaviour is attributed to the transition from the pure amorphous phase to a crystalline liquid phase which occurs at approximately 70°C as shown by using Differential Scanning Calorimetry (DSC). Additionally, the charged nature of asphaltenes and bitumen is also explored using kelvin probe microscopy. Such observations can lead to the development of a rational approach to the fundamental understanding of asphaltene aggregation dynamics and may help in devising novel techniques for the handling and separation of asphaltene aggregates using dielectrophoretic methods.

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