scholarly journals Calibration of a superconducting gravimeter with an absolute atom gravimeter

2021 ◽  
Author(s):  
Sébastien Merlet ◽  
Pierre Gillot ◽  
Bing Cheng ◽  
Romain Karcher ◽  
Almazbek Imanaliev ◽  
...  
Keyword(s):  
Cold Atom ◽  
Superconducting Gravimeter ◽  
Correlation Factor ◽  
Scale Factor ◽  
Common View ◽  
Term Stability ◽  
Long Term Stability ◽  
Superconducting Gravimeters ◽  
The Impact

<p>Atom gravimeters based on atom interferometry offer new measurement capabilities, by combining high sensitivities and accuracies at the best level of a few tens of nm.s<sup>−2</sup> with the possibility to perform continuous measurements. Being absolute meters, their scale factor is accurately determined and do not need calibration. Because of their high sensitivity and low drift, superconducting gravimeters are the key instruments for the continuous monitoring of gravity variations. Nevertheless, being relative meters, they need to be calibrated.</p><p>We revisit a 2015 one month long common view measurement of an absolute cold atom gravimeter (CAG) and a relative iGrav superconducting gravimeter, which we use to investigate the CAG long term stability and calibrate the iGrav scale factor. The initial measurement has already been presented at EGU 2016. Here finalized, we present how it allowed us to push the CAG long-term stability down to the level of 0.5 nm.s<sup>−2</sup>. We investigate the impact of the duration of the measurement on the uncertainty in the determination of the correlation factor and show that it is limited to about 3‰ by the coloured noise of our cold atom gravimeter. A 3-days long measurement session with an additional FG5X absolute gravimeter allows us to directly compare the calibration results obtained with two different absolute meters. Based on our analysis, we expect that with an improvement of its long term stability, the CAG will allow to calibrate the iGrav scale factor to better than the per mille level (1σ level of confidence) after only one-day of concurrent measurements during maximum tidal amplitudes.</p>

One-year long common view measurements with continuous gravimeters

2021 ◽  
Author(s):  
Franck Pereira Dos Santos ◽  
Pierre Vermeulen ◽  
Sylvain Bonvalot ◽  
Germinal Gabalda ◽  
Nicolas Le Moigne ◽  
...  
Keyword(s):  
Geodetic Network ◽  
Cold Atom ◽  
Superconducting Gravimeter ◽  
Common View ◽  
Long Term Stability ◽  
Earth Gravity ◽  
Measurement Session ◽  
One Year ◽  
Metrological Evaluation

<p>Since a few years, several laboratories, institutes or organizations through the world have acquired marketed quantum absolute gravimeters AQG developed by Muquans. Among their potentialities, these new generations of instruments are expected to complement the existing capabilities of long term monitoring of the Earth gravity field. A metrological evaluation of their performances for long-term measurements is thus a first step.</p><p>The LNE-SYRTE gravimetry laboratory in the suburb of Paris, has been designed to accommodate other gravimeters for metrological comparisons, tests and calibrations. Instruments of different classes operate in this well characterized laboratory: a laboratory-based absolute cold atom gravimeter (CAG) and a relative superconducting gravimeter iGrav. Both instruments allow for continuous measurements, Accuracy is guaranteed by the CAG and long-term stability by the iGrav.</p><p>We there have performed a more than one-year long measurement session with the initial version of the marketed quantum gravimeter AQG (AQG-A01).</p><p>An improved version of this AQG (AQG-B01) designed for outdoor measurement and recently acquired by RESIF (the French Seismologic and Geodetic Network) has been also implemented to close this session with a last month of simultaneous data recording involving all the instruments. Finally, we also performed supplementary accuracy tests, in particular to evaluate the Coriolis bias of the two AQG commercial sensors.</p><p>The talk will briefly present the different instruments to rapidly focus on the performances of the AQGs and results of the comparisons.</p>

Separating the impact of oxygen and water on the long-term stability of n-channel perylene diimide thin-film transistors

2015 ◽  
Vol 26 ◽  
pp. 340-344 ◽  
Author(s):  
Ute Zschieschang ◽  
Konstantin Amsharov ◽  
Martin Jansen ◽  
Klaus Kern ◽  
Hagen Klauk ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Perylene Diimide ◽  
Term Stability ◽  
Long Term Stability ◽  
The Impact

Reaching a few 10-15 long-term stability of integrating sphere cold atom clock

2018 ◽  
Vol 16 (7) ◽  
pp. 070201 ◽  
Author(s):  
Yaning Wang Yaning Wang ◽  
Yanling Meng Yanling Meng ◽  
Jinyin Wan Jinyin Wan ◽  
Ling Xiao Ling Xiao ◽  
Mingyuan Yu Mingyuan Yu ◽  
...  
Keyword(s):  
Cold Atom ◽  
Integrating Sphere ◽  
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>

The impact of chronic untreated hyperglycaemia on the long-term stability of paraoxonase 1 (PON1) and antioxidant status in human sera

2013 ◽  
Vol 67 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Muiruri Macharia ◽  
Andre P Kengne ◽  
Diane M Blackhurst ◽  
Rajiv T Erasmus ◽  
Tandi E Matsha
Keyword(s):  
Antioxidant Status ◽  
Paraoxonase 1 ◽  
Term Stability ◽  
Long Term Stability ◽  
Human Sera ◽  
The Impact

scholarly journals Sensing with Chirality Pure near Infrared Fluorescent Carbon Nanotubes

2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dna Sequences ◽  
Near Infrared ◽  
Single Wall Carbon Nanotubes ◽  
Term Stability ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Main Challenge ◽  
The Impact

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.

scholarly journals Sensing with Chirality Pure near Infrared Fluorescent Carbon Nanotubes

2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dna Sequences ◽  
Near Infrared ◽  
Single Wall Carbon Nanotubes ◽  
Term Stability ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Main Challenge ◽  
The Impact

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.

scholarly journals Lip-to-incisor Relationship and Postorthodontic Long-term Stability of Cover-bite Treatment

2006 ◽  
Vol 76 (6) ◽  
pp. 942-949 ◽  
Author(s):  
Bernd G. Lapatki ◽  
Dirk Baustert ◽  
Jürgen Schulte-Mönting ◽  
Sibylle Frucht ◽  
Irmtrud E. Jonas
Keyword(s):  
Central Incisor ◽  
Lower Lip ◽  
Maxillary Central Incisor ◽  
Term Stability ◽  
Long Term Stability ◽  
Lateral Cephalograms ◽  
Inducing Factors ◽  
Line Level ◽  
The Impact

Abstract Objective: To investigate the impact of a persisting high lip line and other potential relapse-inducing factors on long-term stability of orthodontic correction of retroinclined maxillary central incisors. Materials and Methods: Thirty-one cover-bite (“Deckbiss”) patients with retroinclined maxillary central incisors and a deep frontal overbite were evaluated. The maxillary central incisor inclination was determined odontometrically with study models made pretreatment, posttreatment, and at a follow-up examination (mean posttherapeutic interval: 9.0 years). The lip-to-incisor relationship, the interincisal angle, and the anteroposterior maxillary central incisor position were measured on lateral cephalograms taken after active treatment. Results: The relapse tendency of the orthodontic correction of the retroinclined maxillary central incisors displayed great interindividual variability with a range of posttherapeutic inclination change of −6.75° to +8.00°. Multiple regression analysis revealed an increased tendency for relapse in patients with (1) a high posttherapeutic (dorsal) lip line level combined with the maxillary central incisor and lower lip contact only in the incisal crown area (P < .01) and (2) a marked therapeutically induced inclination change of the maxillary central incisors (P < .05). Interrelations between the relapse of the corrected maxillary central incisors and other evaluated parameters were not statistically significant. Conclusions: For maximum treatment stability, the elimination of an excessive overlap of the upper incisors by the lower lip should be regarded as one of the most important therapeutic objectives when treating this malocclusion.

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