Role of Dislocations in the Electrical Conductivity of CdS

1981 ◽  
Vol 46 (17) ◽  
pp. 1159-1162 ◽  
Author(s):  
A. R. Hutson
2020 ◽  
pp. 15-27

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.


2018 ◽  
Vol 22 (2) ◽  
pp. 1629-1648 ◽  
Author(s):  
Etienne Bresciani ◽  
Roger H. Cranswick ◽  
Eddie W. Banks ◽  
Jordi Batlle-Aguilar ◽  
Peter G. Cook ◽  
...  

Abstract. Numerous basin aquifers in arid and semi-arid regions of the world derive a significant portion of their recharge from adjacent mountains. Such recharge can effectively occur through either stream infiltration in the mountain-front zone (mountain-front recharge, MFR) or subsurface flow from the mountain (mountain-block recharge, MBR). While a thorough understanding of recharge mechanisms is critical for conceptualizing and managing groundwater systems, distinguishing between MFR and MBR is difficult. We present an approach that uses hydraulic head, chloride and electrical conductivity (EC) data to distinguish between MFR and MBR. These variables are inexpensive to measure, and may be readily available from hydrogeological databases in many cases. Hydraulic heads can provide information on groundwater flow directions and stream–aquifer interactions, while chloride concentrations and EC values can be used to distinguish between different water sources if these have a distinct signature. Such information can provide evidence for the occurrence or absence of MFR and MBR. This approach is tested through application to the Adelaide Plains basin, South Australia. The recharge mechanisms of this basin have long been debated, in part due to difficulties in understanding the hydraulic role of faults. Both hydraulic head and chloride (equivalently, EC) data consistently suggest that streams are gaining in the adjacent Mount Lofty Ranges and losing when entering the basin. Moreover, the data indicate that not only the Quaternary aquifers but also the deeper Tertiary aquifers are recharged through MFR and not MBR. It is expected that this finding will have a significant impact on the management of water resources in the region. This study demonstrates the relevance of using hydraulic head, chloride and EC data to distinguish between MFR and MBR.


2019 ◽  
Vol 32 ◽  
pp. 80-89
Author(s):  
Jameel H. Hiji ◽  
Abbas M. Jasim ◽  
Awatif N. Jerry

The experiment was conducted during 2017-2018 and 2018-2019 winter seasons at Abu Al-Khaseeb District at basrah /Iraq on sandy loam soil  to study the effect of sulfur at five concentration ( 0 , 500 , 1000, 1500 and 2000) kg. Ha-1, clean salt at three concentration (0, 0.5 and 1.0) ml. L-1, two cultivars of lettuce local and fajr and interaction among them  at electrical conductivity of the irrigation water (7.85 and 9.69) dS.m-1.  Result showed significant reduction in the activity of catalase (CAT) and peroxidase (POD) enzymes and proline content in all treatments of sulfur and clean salt especially at 2000 Kg. Ha-1 sulfur and clean salt at 1.0 ml L-1had significantly decrease in CAT activity (295.80 ? 341.65) U mg–1 FW, POD activity (7.86? 8.98) U mg–1 FW and proline (0.50 ? 0.80) mg g-1DW, comparing with control of CAT activity (663.21, 814.65) U mg–1 FW and POD activity (13.83, 15.52) mg–1 FW and proline (1.19, 2.03) mg g-1DW, respectively for two seasons due to the role of sulfur and clean salt ameliorates the adverse effects of salinity on plants. Fajr lettuce is more salt-tolerant than local due to less antioxidant enzyme levels POD, CAT and proline.


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