scholarly journals Mecanismes De Contamination Des Eaux Souterraines Dans Le Secteur Du Lac Mbeubeuss, Dakar, Senegal

2018 ◽  
Vol 14 (27) ◽  
pp. 254
Author(s):  
Essouli Olivier Florent ◽  
Gladima-Siby Sophie Aïssatou ◽  
Miyouna Timothée ◽  
Matini Laurent ◽  
Faye Serigne
Keyword(s):  
Electrical Conductivity ◽  
Chemical Elements ◽  
Anthropogenic Pollution ◽  
True Value ◽  
Dry Lake ◽  
Major Chemical ◽  
Eaux Souterraines ◽  
The Relationship ◽  
Geological Formations ◽  
Lake Site

The physicochemistry of groundwater in the immediate environment of the dump, and its surroundings, shows that the true value of the electrical conductivity of groundwater is close to 2000 μS / cm. The value of electrical conductivity that is greater than 2000 μS / cm demonstrates groundwater contamination through the Mbeubeuss Lake landfill, with chemical groundwater facies dominated by Sodium Chloride, Potassium Chloride, and Calcium Chloride. The study of the unsaturated zone of the aquifer and the relationship between the major chemical elements of groundwater, rainwater, and seawater made it possible to specify, on one hand, the sources of mineralization of the groundwater at the Mbeubeuss Lake site and its surroundings. Indeed, the situation close to the sea would suggest a considerable intake of salts by aerosols and sea spray. Based on contribution to this study, the influence of the old sediments of the dry Lake Mbeubeuss and the percolation of leachates resulting from the decomposition of garbage landfilled under the action of rainwater would be added. On the other hand, this study also made it possible to determine the main processes of controlling the mineralization of groundwater. This includes the marine inputs, the dissolution-precipitation of clay minerals present in the geological formations constituting the aquifer, the dilution- concentration, evaporation, and anthropogenic pollution.

scholarly journals Hydrochemical Approach to Groundwater in the Environment of the Public Discharge of Lake Mbeubeuss (Dakar, Senegal)

2022 ◽  
Vol 8 (1) ◽  
pp. 458-465
Author(s):  
Olivier Florent Essouli ◽  
Edmond NICAISE Malanda Nimy ◽  
Timothée Miyouna ◽  
Sophie Aïssatou Gladima-Siby ◽  
Laurent Matini ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Chemical Elements ◽  
Chloride Ion ◽  
Anthropogenic Pollution ◽  
Household Waste ◽  
Sea Spray ◽  
Lake Area ◽  
The Public ◽  
Ground Waters ◽  
True Value

To determine the origin and the processes of groundwater mineralization in the Mbeubeuss lake area, the major ion concentrations of the groundwater were compared to those of the rainwaters which constitute the input function of the aquifer of the Quaternary sands in the area of lake Mbeubeuss. The physico-chemistry of groundwater near the public discharge and its surroundings, has shown that the true value of the electrical conductivity of waters are around 2000 µS/cm. Values of electrical conductivity greater than 2000 µS/cm would represent the particular mineralization of ground waters by the public discharge of lake Mbeubeuss. The chemical facies of ground waters are dominated by the sodium and potassium chloride and calcium chloride facies. The study of the relationship between the major chemical elements and the chloride ion and the representation in the modified Chadha diagram of the chemical analyzes of ground waters from the campaigns of July 1998, July 2002 and March 2003, made it possible to highlight the different sources and processes controlling the mineralization of ground waters in the Mbeubeuss Lake area. Despite the proximity to the sea which suggests a considerable contribution of salts by aerosols and sea spray, the mineralization of ground waters in the area of lake Mbeubeuss is largely due to leachate from household waste and the influence of old sediments of the dry lake Mbeubeuss. The main processes controlling the mineralization of ground waters are marine contributions (aerosols and sea spray), dissolution-precipitation of minerals from the aquifer matrix, atmospheric CO2 diffusion, base exchanges, dilution-concentration and anthropogenic pollution.

The relationship between chemical elements in soil and whole blood, and fluorosis induced by coal-fired pollution

2013 ◽  
Vol 186 (4) ◽  
pp. 2081-2088 ◽  
Author(s):  
Hao Wang ◽  
Lihong Mu ◽  
Miao Jiang ◽  
Yingxiong Wang ◽  
Wei Yan ◽  
...  
Keyword(s):  
Whole Blood ◽  
Chemical Elements ◽  
The Relationship

scholarly journals Prediction of Reproductive Success in Multiparous First Service Dairy Cows by Parameters from In-Line Sensors

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 334
Author(s):  
Ramūnas Antanaitis ◽  
Vida Juozaitienė ◽  
Dovilė Malašauskienė ◽  
Mindaugas Televičius ◽  
Mingaudas Urbutis ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Blood Parameters ◽  
Negative Energy ◽  
Hydroxybutyric Acid ◽  
Pregnancy Status ◽  
Group A ◽  
Biochemical Indices ◽  
Relationship Of ◽  
The Relationship

The aim of the current study was to evaluate the relationship of different parameters from an automatic milking system (AMS) with the pregnancy status of multiparous cows at first service and to assess the accuracy of such a follow-up with regard to blood parameters. Before the insemination of cows, blood samples for measuring biochemical indices were taken from the coccygeal vessels and the concentrations of blood serum albumin (ALB), cortisol, non-esterified fatty acids (NEFA) and the activities of aspartate aminotransferase (AST) and gamma glutamyltransferase (GGT) were determined. From oestrus day to seven days after oestrus, the following parameters were registered: milk yield (MY), electric milk conductivity, lactate dehydrogenase (LDH) and β-hydroxybutyric acid (BHB). The pregnancy status was evaluated using ultrasound “Easy scan” 30–35 days after insemination. Cows were grouped by reproductive status: PG− (non-pregnant; n = 48) and PG+ (pregnant; n = 44). The BHB level in PG− cows was 1.2 times higher (p < 0.005). The electrical conductivity of milk was statistically significantly higher in all quarters of PG− cows (1.07 times) than of PG+ cows (p < 0.05). The arithmetic mean of blood GGT was 1.61 times higher in PG− cows and the NEFA value 1.23 times higher (p < 0.05) compared with the PG+ group. The liver function was affected, the average ALB of PG− cows was 1.19 times lower (p < 0.05) and the AST activity was 1.16 times lower (p < 0.05) compared with PG+ cows. The non-pregnant group had a negative energy balance demonstrated by high in-line milk BHB and high blood NEFA concentrations. We found a greater number of cows with cortisol >0.0.75 mg/dL in the non-pregnant group. A higher milk electrical conductivity in the non-pregnant cows pointed towards a greater risk of mastitis while higher GGT activities together with lower albumin concentrations indicated that the cows were more affected by oxidative stress.

The Fairbanks earthquakes of June 21, 1967; aftershock distribution, focal mechanisms, and crustal parameters

1969 ◽  
Vol 59 (1) ◽  
pp. 73-100
Author(s):  
Larry Gedney ◽  
Eduard Berg
Keyword(s):  
P Wave ◽  
Fault System ◽  
Crustal Layer ◽  
Near Surface ◽  
Fault Surface ◽  
True Value ◽  
Regional Tectonic ◽  
Tectonic System ◽  
Relationship Of ◽  
The Relationship

Abstract A series of moderately severe earthquakes occurred in the vicinity of Fairbanks, Alaska, on the morning of June 21, 1967. During the following months, many thousands of aftershocks were recorded in order to outline the aftershock zone and to resolve the focal mechanism and its relation to the regional tectonic system. No fault is visible at the surface in this area. Foci were found to occupy a relatively small volume in the shape of an ablate cylinder tilted about 30° from the vertical. The center of the zone lay about 12 kilometers southeast of Fairbanks. Focal depths ranged from near-surface to 25 kilometers, although most were in the range 9-16 km. In the course of the investigation, it was found that the Jeffreys and Bullen velocity of 5.56 km/sec for the P wave in the upper crustal layer is very near the true value for this arec, and that the use of 1.69 for the Vp/Vs ratio gives good results in most cases. The proposed faulting mechanism involves nearly equal components of right-lateral strike slip, and normal faulting with northeast side downthrown on a system of sub-parallel faults striking N40°W. The fault surface appears to be curved—dipping from near vertical close to the surface to less steep northeast dips at greater depths. The relationship of this fault system with the grosser aspects of regional tectonism is not clear.

scholarly journals Investigation of the relationship between landform classes and electrical conductivity (EC) of water and soil using a fuzzy model in a GIS environment

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 873-880
Author(s):  
Marzieh Mokarram ◽  
Dinesh Sathyamoorthy
Keyword(s):  
Electrical Conductivity ◽  
Fuzzy Model ◽  
Chemical Properties ◽  
Geographical Information ◽  
Fars Province ◽  
Fuzzy Method ◽  
The North ◽  
The Relationship ◽  
Very High ◽  
Soil And Water

Abstract. Soil genesis is highly dependent on landforms as they control the erosional processes and the soil physical and chemical properties. The relationship between landform classification and electrical conductivity (EC) of soil and water in the northern part of Meharloo watershed, Fars province, Iran, was investigated using a combination of a geographical information system (GIS) and a fuzzy model. The results of the fuzzy method for water EC showed 36.6 % of the land to be moderately land suitable for agriculture; high, 31.69 %; and very high, 31.65 %. In comparison, the results of the fuzzy method for soil EC showed 24.31 % of the land to be as not suitable for agriculture (low class); moderate, 11.78 %; high, 25.74 %; and very high, 38.16 %. In total, the land suitable for agriculture with low EC is located in the north and northeast of the study area. The relationship between landform and EC shows that EC of water is high for the valley classes, while the EC of soil is high in the upland drainage class. In addition, the lowest EC levels for soil and water are in the plains class.

Laboratory test of snow wetness influence on electrical conductivity measured with ground penetrating radar

2009 ◽  
Vol 40 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Nils Granlund ◽  
Angela Lundberg ◽  
James Feiccabrino ◽  
David Gustafsson
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Laboratory Test ◽  
Liquid Water ◽  
Ground Penetrating Radar ◽  
Wave Attenuation ◽  
Radar Measurements ◽  
Ground Penetrating ◽  
Radar Wave ◽  
The Relationship

Ground penetrating radar operated from helicopters or snowmobiles is used to determine snow water equivalent (SWE) for annual snowpacks from radar wave two-way travel time. However, presence of liquid water in a snowpack is known to decrease the radar wave velocity, which for a typical snowpack with 5% (by volume) liquid water can lead to an overestimation of SWE by about 20%. It would therefore be beneficial if radar measurements could also be used to determine snow wetness. Our approach is to use radar wave attenuation in the snowpack, which depends on electrical properties of snow (permittivity and conductivity) which in turn depend on snow wetness. The relationship between radar wave attenuation and these electrical properties can be derived theoretically, while the relationship between electrical permittivity and snow wetness follows a known empirical formula, which also includes snow density. Snow wetness can therefore be determined from radar wave attenuation if the relationship between electrical conductivity and snow wetness is also known. In a laboratory test, three sets of measurements were made on initially dry 1 m thick snowpacks. Snow wetness was controlled by stepwise addition of water between radar measurements, and a linear relationship between electrical conductivity and snow wetness was established.

scholarly journals POLARIMETRIC CALIBRATION OF L-BAND AIRBORNE SAR DATA

2020 ◽  
Vol V-1-2020 ◽  
pp. 369-374
Author(s):  
A. Maiti ◽  
S. Kumar ◽  
V. Tolpekin ◽  
S. Agarwal
Keyword(s):  
Accurate Estimation ◽  
Distortion Model ◽  
Propagation Of Uncertainty ◽  
Statistical Measures ◽  
Dry Lake ◽  
L Band ◽  
Airborne Sar ◽  
Optimal Kernel ◽  
Target Characteristics ◽  
The Relationship

Abstract. The PolSAR calibration ensures that the relationship between the SAR observations and the target characteristics on the ground are consistent and resembles the theoretical estimation which in turn improves the overall data quality. Essentially, calibration prevents the propagation of uncertainty into further analysis to characterise the target. In this study, the UAVSAR L-Band data of Rosamond dry lake bed has been calibrated. The calibration of amplitude and phase are carried out with the help of the corner reflector array present in the Rosamond site. The dataset is further calibrated for the crosstalk and channel imbalance using the Quegan’s distortion model. Since the crosstalk distortion model requires an accurate estimation of the covariance matrix, the optimal kernel size for the its computation is selected based on the distortion model behaviour with varying window sizes. Furthermore, the effectiveness of the calibration process has been studied using polarimetric signatures and other statistical measures.

Studies on water damage in mungbean. II. Electrical conductivity of seed leachate as an assay of level of damage

1995 ◽  
Vol 46 (5) ◽  
pp. 901 ◽  
Author(s):  
RW Williams ◽  
RJ Lawn ◽  
BC Imrie ◽  
DE Byth
Keyword(s):  
Electrical Conductivity ◽  
Previous Exposure ◽  
Wetting And Drying ◽  
Resistant Cultivars ◽  
Visual Damage ◽  
Seed Leachate ◽  
Weather Damage ◽  
The Relationship ◽  
Weathering Process ◽  
Bean Sprouts

Weather-damaged seeds of mungbean are unsuitable for the production of bean sprouts and some other food uses. The breeding of resistant cultivars requires an understanding of the weathering process and the use of suitable criteria for measuring the degree of weather damage. The aim of this research was to describe the effect of weathering on the electrical conductivity of leachate from exposed seeds and to evaluate this technique as a means of discriminating among levels of weather damage. Seeds were weathered in the field or immersed in water in the laboratory for varying durations during one or more cycles of wetting and drying. Leachate conductivities generally increased with increasing visual damage and decreasing viability of seeds. When measurements of conductivity were delayed, the results appeared to be confounded by the extent to which solutes were lost during previous exposure/s to weathering. Measurements soon after immersion tended to reduce this effect and to better reflect the level of weather damage in seeds of mungbean. It was concluded that leachate conductivity technique can provide a reliable assay of weather damage in mungbean. When seeds have been exposed to severe weathering, however, the relationship breaks down, and the technique can give misleading results.

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