scholarly journals Analysis of Temperature Anomalies during Thermal Monitoring of Frozen Wall Formation

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 297
Author(s):  
Mikhail Semin ◽  
Ivan Golovatyi ◽  
Aleksei Pugin
Keyword(s):  
Sharp Decrease ◽  
Hydraulic Modeling ◽  
Distributed Temperature Sensing ◽  
Thermal Monitoring ◽  
Mine Shaft ◽  
Entire Volume ◽  
Artificial Freezing ◽  
Frozen Wall ◽  
Potash Mine ◽  
Local Anomalies

The paper describes a distributed temperature sensing system that was used to monitor the artificial freezing of soils during the construction of a potash mine shaft. The technique of reconstructing the temperature field by solving the inverse problem in the entire volume of frozen soils using the measured temperatures in four thermal monitoring (TM) wells is described. Two local anomalies in temperature distributions in TM wells are described and analyzed theoretically using thermo-hydraulic modeling. The first anomaly concerns the asymmetric temperature distribution in one of the soil layers and is associated with the influence of natural groundwater flow in the horizontal direction. The second anomaly consists of a sharp decrease in water temperature in the section of the TM well located inside the freezing contour. Calculations showed that it is most likely associated with the entry of cold groundwater from the overlying layers of soils through a well filter at a depth of 160 m and the subsequent movement of the water up the well.

UNDERGROUND APPLICATIONS OF SEISMIC MEASUREMENTS IN A SASKATCHEWAN POTASH MINE

Geophysics ◽  
1969 ◽  
Vol 34 (6) ◽  
pp. 906-915 ◽  
Author(s):  
D. J. Gendzwill
Keyword(s):  
Seismic Refraction ◽  
Salt Formation ◽  
Mine Shaft ◽  
Relative Time ◽  
Refraction Method ◽  
Seismic Records ◽  
Underground Workings ◽  
Seismic Refraction Method ◽  
Potash Mine ◽  
Seismic Measurements

The seismic refraction method is used underground in a Saskatchewan potash mine to monitor the thickness of the salt formation over the mine. Frequencies over 100 Hz characterize the seismic records. Mining machines create noise problems. Records are picked with 0.1 ms precision and a computer used to make the calculations. The statistical random error in the interpretation ranges from ±4 ft to ±15 ft for typical thicknesses of about 130 ft. Seismic techniques have aided in locating a nearly completed mine shaft with respect to existing underground workings. The geophysical work was originally intended as a verification and check against gross errors in the conventional surveying. Preliminary tests showed that the method would work with acceptable accuracy. Interpretation was made using only the relative time differences between geophones. The predicted position of the shaft center was 340±2 ft northeast and 235±10 ft northwest of a reference point. This compares with the actual position of 342.4 ft northeast and 228.5 ft northwest of the reference position determined upon completion of the shaft connection.

scholarly journals Theoretical analysis of frozen wall dynamics during transition to ice holding stage

2020 ◽  
Vol 243 ◽  
pp. 319
Author(s):  
Mikhail Semin ◽  
Lev Levin ◽  
Aleksandr Bogomyagkov
Keyword(s):  
Rock Mass ◽  
Pore Water ◽  
Wall Thickness ◽  
Operation Mode ◽  
Emergency Operation ◽  
Freezing Temperature ◽  
Normal Operation ◽  
Emergency Situations ◽  
Frozen Wall ◽  
Potash Mine

Series of calculations for the artificial freezing of the rock mass during construction of mineshafts for the conditions of a potash mine in development was carried out. Numerical solution was obtained through the finite element method using ANSYS software package. Numerical dependencies of frozen wall thickness on time in the ice growing stage and ice holding stage are obtained for two layers of the rock mass with different thermophysical properties. External and internal ice wall boundaries were calculated in two ways: by the actual freezing temperature of pore water and by the temperature of –8 °С, at which laboratory measurements of frozen rocks' strength were carried out. Normal operation mode of the freezing station, as well as the emergency mode, associated with the failure of one of the freezing columns, are considered. Dependence of a decrease in frozen wall thickness in the ice holding stage on the duration of the ice growing stage was studied. It was determined that in emergency operation mode of the freezing system, frozen wall thickness by the –8 °C isotherm can decrease by more than 1.5 m. In this case frozen wall thickness by the isotherm of actual freezing of water almost always maintains positive dynamics. It is shown that when analyzing frozen wall thickness using the isotherm of actual freezing of pore water, it is not possible to assess the danger of emergency situations associated with the failure of freezing columns.

Electrochemical nucleation and growth of copper on iron and aluminum: A TEM study of industrial copper cementation

1978 ◽  
Vol 36 (1) ◽  
pp. 454-455
Author(s):  
L.E. Murr ◽  
V. Annamalai
Keyword(s):  
Metal Surface ◽  
Copper Deposit ◽  
Nucleation And Growth ◽  
16Th Century ◽  
Electrochemical Reactions ◽  
Mine Shaft ◽  
De Re ◽  
Copper Precipitation ◽  
Electrochemical Nucleation ◽  
Interesting System

Georgius Agricola in 1556 in his classical book, “De Re Metallica”, mentioned a strange water drawn from a mine shaft near Schmölnitz in Hungary that eroded iron and turned it into copper. This precipitation (or cementation) of copper on iron was employed as a commercial technique for producing copper at the Rio Tinto Mines in Spain in the 16th Century, and it continues today to account for as much as 15 percent of the copper produced by several U.S. copper companies.In addition to the Cu/Fe system, many other similar heterogeneous, electrochemical reactions can occur where ions from solution are reduced to metal on a more electropositive metal surface. In the case of copper precipitation from solution, aluminum is also an interesting system because of economic, environmental (ecological) and energy considerations. In studies of copper cementation on aluminum as an alternative to the historical Cu/Fe system, it was noticed that the two systems (Cu/Fe and Cu/Al) were kinetically very different, and that this difference was due in large part to differences in the structure of the residual, cement-copper deposit.

Verbal Punishment of Disfluencies in Normal Speakers

1965 ◽  
Vol 8 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Gerald M. Siegel ◽  
Richard R. Martin
Keyword(s):  
Sharp Decrease ◽  
Random Presentation ◽  
Random Schedule

Forty normal speakers were divided into two groups to study the effects of two types of verbal punishment of disfluencies. The two conditions, Random and Contingent, were divided into three segments each. Punishment was not delivered in Segments 1 or 3. Segment 2 presented Random subjects with the tape recorded word “wrong” on a predetermined random schedule. Contingent subjects were delivered the word “wrong” after each disfluency. Random presentation of “wrong” did not significantly affect rate of disfluencies. Contingent presentation resulted in a sharp decrease in disfluencies during Segment 2, and an increase in disfluencies during Segment 3.

Analyzing Pump Energy through Hydraulic Modeling

2015 ◽  
Author(s):  
Ron Miller ◽  
Tracey Liberi ◽  
John Scioscia
Keyword(s):  
Pump Energy ◽  
Hydraulic Modeling

Enzymic Correlates of Development, Secretory Function and Regression of Follicles and Corpora Lutea in the Bovine Ovary. PART II: Formation, Development and Involution of Corpora Lutea

1968 ◽  
Vol 59 (2_Suppl) ◽  
pp. S35-S51 ◽  
Author(s):  
B. L. Lobel ◽  
E. Levy
Keyword(s):  
Corpus Luteum ◽  
Vascular System ◽  
Hydrolytic Enzymes ◽  
Sharp Decrease ◽  
Cellular Growth ◽  
Corpora Lutea ◽  
Cell Nuclei ◽  
Steroid Synthesis ◽  
Luteal Cells ◽  
Vascular Walls

ABSTRACT Activities of various hydrolases and dehydrogenases were studied during the formation, development and involution of cyclic corpora lutea and in the corpora lutea of early pregnancy. At 24 hours postovulation the luteal cells, whether of granulosal or thecal origin, contained demonstrable levels of Δ5-3β-hydroxysteroid dehydrogenase and the NADP and NADPH2 diaphorases. During the period of proliferation and cellular growth, enzymic activities in the luteal cells were moderate at first, and then increased. In the mature corpus luteum, activities of the dehydrogenases occurred in all luteal cells but were most intense in the large polymorphic luteal cells. Activities of hydrolytic enzymes, low in the immediate postovulatory period, increased with the development of the vascular system. Enzymic characteristics of corpora lutea of gestation were similar to those of cyclic corpora, except for phosphorylase activity which was observed in luteal cells in gestational corpora, but confined to the vascular walls in cyclic corpora. No increase in activities of 17β- and 20β-hydroxysteroid dehydrogenases (above those seen in pre-ovulatory follicles) were observed after incubation of sections of either mature cyclic or gestational corpora. Involution of cyclic corpora lutea began with degenerative changes in the blood vessels: pyknosis of the endothelial cell nuclei and a sudden decline in activities of hydrolytic enzymes in the vascular walls. Subsequently, the luteal cells showed a sharp decrease in activities of the dehydrogenases as well as other signs of regressive change. The cytochemical findings are discussed in relation to biochemical observations on steroid synthesis by the bovine corpus luteum.

Effects of progesterone induced postmaturity on CBG and pituitary-adrenal activities in the rat foetus

1986 ◽  
Vol 112 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Jean Paul Dupouy ◽  
Alain Chatelain
Keyword(s):  
Binding Capacity ◽  
Sharp Decrease ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Rat Pups ◽  
Body Weights ◽  
Normal Rat ◽  
Severe Jaundice ◽  
High Level ◽  
Subsequent Rise

Abstract. CBG and pituitary-adrenal activities were investigated in intact rat foetuses, in newborns spontaneously delivered by vaginal way and in postmature foetuses from mothers with delayed parturition caused by daily progesterone injection from day 20 of gestation. The postmature foetuses had lower body weights and higher adrenal weights on day 22, 23 and 24 of gestation than newborns of the same conceptional age. The corticosterone binding capacity of the plasma as well as the binding capacity of CBG for corticosterone decreased in intact foetuses for the last 3 days of gestation and stayed very low in pups from day 0 to day 8 postpartum. These parameters decreased more slowly in postmature foetuses; however, the differences between the latter and intact foetuses or newborns were not statistically significant. Similar evolution occurred in intact pregnant and suckling females as well as in females with prolonged gestation. The fall in CBG activity in normal rat pups and the subsequent rise in free steroids could explain a sharp decrease in plasma ACTH levels as well as the drop in adrenal and plasma corticosterone concentration. In foetuses with prolonged gestation, the same phenomenon did not occur. Stress conditions produced by maintaining growing foetuses in utero and the development of severe jaundice maintained high ACTH levels. In contrast, the fall in adrenal and plasma corticosterone concentrations in spite of the high level of circulating ACTH could be mainly due to the progesterone inhibition of the steroidogenic activity of the foetal adrenals.

Photosynthetic activity of spring wheat depending on the conditions of water supply

2020 ◽  
Author(s):  
I.I. Seregina ◽  
◽  
I.G. Makarskaya
Keyword(s):  
Water Supply ◽  
Spring Wheat ◽  
Sodium Selenite ◽  
Photosynthetic Activity ◽  
Wheat Variety ◽  
Sharp Decrease ◽  
Soil Culture ◽  
Growing Conditions ◽  
Spring Wheat Variety ◽  
Excessive Water

Abstract:In model experiments in soil culture, the effect of different methods of treatment with sodium selenite on the photosynthetic activity of spring wheat variety Zlata was studied under extreme growing conditions. Under drought conditions, the inhibition of the growth of the photosynthetic surface of spring wheat plants was revealed. Under conditions of excessive water supply, a sharp decrease in the area of the assimilating surface of wheat plants was observed. The positive effect of sodium selenite solution on the photosynthetic activity of spring wheat plants was established with insufficient and excessive water supply to wheat plants.

Application of GIS, Hydraulic and Hydrologic Modelling to Investigate the Changes of Flood Inundation Characteristics due to the Construction of Dams for different scenarios

2018 ◽  
Vol 1 (2) ◽  
pp. 61-77
Author(s):  
Hossameldin M. Elhanafy
Keyword(s):  
Fluid Mechanics ◽  
Flood Control ◽  
Reduction Rate ◽  
Hydraulic Modeling ◽  
Direct Result ◽  
Flood Inundation ◽  
High Ability ◽  
The West ◽  
Hydrologic Modelling ◽  
New Location

The novelty of the research project reported in this paper is the coupling of hydrological and hydraulic modeling which are based on the first principal of fluid mechanics for the simulation of flash floods at Wadi Elarish watershed to optimize the a new location of another dam rather than Elrawfa dam which already exist. Results show that, the optimum scenario is obtained by the construction of the west dam. As a direct result of this dam, the downstream inundated area can be reduced up to 15.7 % as function of reservoir available storage behind the dam. Furthermore, calculations showed that the reduction rate of inundated area for 50-year floods is largely more than 100-year floods, implies the high ability of west dam on flood control especially for floods with shorter return period.

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