scholarly journals LONG-TERM STABILITY MONITORING OF THE MINING BLOCKS IN ESTONIAN OIL SHALE MINES

2006 ◽  
Vol 1 ◽  
pp. 206
Author(s):  
J.-R. Pastarus
Keyword(s):  
Influence Factors ◽  
Monitoring Methods ◽  
Mining System ◽  
Term Stability ◽  
Long Term Stability ◽  
Room And Pillar Mining ◽  
Convergence Method ◽  
Pillar Mining

This paper deals with long-term stability prediction and monitoring methods by room-and-pillar mining system. Roof-to-floor convergence and conditional thickness methods suit for calculations. They allow determination of the location, area and time of the collapse in a mining block. The uncertainty in time is less than 10 % at the 95 % confidence level. Roof-to-floor convergence method is preferred; it takes into consideration all the geological and mining feature in the critical area. Conditional thickness method demands supplementary investigations, determination of the influence factors on the process. The applicability of these methods is clearly demonstrated.

Determination of Long-Term Stability and Quality of HT-PEM MEAs

2018 ◽  
Vol 86 (13) ◽  
pp. 301-314
Author(s):  
Maren Rastedt ◽  
Julian Büsselmann ◽  
Tomas Klicpera ◽  
Karsten Reinwald ◽  
Nadine Pilinski ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability

Quantum Absolute Sensors for Gravity Measurements

2020 ◽  
Author(s):  
Sébastien Merlet ◽  
Raphael Piccon ◽  
Sumit Sarkar ◽  
Franck Pereira Dos Santos
Keyword(s):  
Ultracold Atoms ◽  
Cold Atom ◽  
Large Momentum ◽  
Magnetic Traps ◽  
Term Stability ◽  
Long Term Stability ◽  
Dual Sensor ◽  
Gravity Measurements

<p>Gravity measurements are performed with two different classes of instruments: gravimeters, most widely used, measure the gravity acceleration gand its variations, whereas gradiometers measure its gradient.</p><p>Quantum gravity sensors, based on cold atom interferometry techniques, can offer higher sensitivities and accuracies than current state of the art commercial available technologies. Their limits in performances, both in terms of accuracy and long term stability, are linked to the temperature of the atomic cloud, in the low µK range, and more specifically, to the residual ballistic expansion of the atomic sources in the laser beams. To overcome these limits, we use ultracold atoms in the nano-kelvin range in our sensors.</p><p>I will first present our Cold Atom Gravimeter (CAG) used for the determination of the Planck constant with the LNE Kibble Balance [1]. It performs continuously 3 gravity measurements per second with a demonstrated long term stability of 0.06 nano-gin 40 000 s of measurement. Using ultracold atoms produced by evaporative cooling in a crossed dipole trap as a source, its accuracy, which is still to be improved, is currently at the level of 2 nano-g. This makes our CAG, the more accurate gravimeter [2]. It detects water table level variations. Then I will describe a « dual sensor » which performs simultaneous measurements of g and its gradient. This offers in principle the possibility to resolve, by combining these two signals, the ambiguities in the determination of the positions and masses of the sources, offering new perspectives for applications. It uses cold atom sources for proof of principle demonstrations [3, 4] and will soon combine ultra-cold atomic samples produced by magnetic traps on a chip and large momentum beamsplitters. With these two key elements, the gradiometer will perform measurements in the sub-E sensitivity range in 1 s measurement time on the ground. Such a level of performances opens new prospects for on field and on board gravity mapping, for drift correction of inertial measurement units in navigation, for geophysics and for fundamental physics.</p><div> <strong>References</strong></div><p>[1] M. Thomas et al. Metrologia <strong>54</strong>, 468-480 (2017)</p><p>[2] R. Karcher, et al. New J. Phys. <strong>20</strong>, 113041 (2018)</p><p>[3] M. Langlois et al. Phys. Rev. A <strong>96</strong>, 053624 (2017)</p><p>[4] R. Caldani et al. Phys. Rev. A <strong>99</strong>, 033601 (2019)</p>

Pt-NiCo Nanostructures with Facilitated Electrocatalytic Activities for Sensitive Determination of Intracellular Thiols with Long-Term Stability

2010 ◽  
Vol 16 (36) ◽  
pp. 11115-11120 ◽  
Author(s):  
Feng Zhang ◽  
Ming Wen ◽  
Mingzhu Cheng ◽  
Di Liu ◽  
Anwei Zhu ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability ◽  
Sensitive Determination

scholarly journals Long-term stability of measurements of the elemental composition of steel using a vacuum atomic emission spectrometer «Grand-Expert»

2019 ◽  
Vol 85 (1II)) ◽  
pp. 135-138
Author(s):  
I. N. Kuropyatnik
Keyword(s):  
Standard Sample ◽  
Atomic Emission ◽  
Elemental Content ◽  
Expanded Uncertainty ◽  
Term Stability ◽  
Relative Expanded Uncertainty ◽  
Long Term Stability ◽  
Atomic Emission Spectrometer

A study of the repeatability and long-term stability of elemental content measurements in a UG20 standard sample using a vacuum atomic emission spectrometer «Grand-Expert» was carried out on time scales of 10 min and 1 h. The values of standard and expanded uncertainty of the results of carbon, chromium, manganese, nickel and silicon determination which characterize the repeatability and long-term stability of measurements were calculated. It has been shown that a vacuum atomic emission spectrometer «Grand-Expert» provides determination of the content of alloying elements in steel with a relative expanded uncertainty of 1 – 2% whereas measurements of carbon content are characterized by higher relative expanded uncertainty of about 3%.

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