The bistatic LGS scheme for sodium layer height characterization (based on the Teide Observatory experimental setup)

Author(s):  
Julio A. Castro-Almazán ◽  
Jesús J. Fuensalida ◽  
Ángel Alonso ◽  
Sergio Chueca
1964 ◽  
Vol 17 (2) ◽  
pp. 257
Author(s):  
GR Cresswell

Measurements of the twilight sky luminosity variations in Na D at Saskatoon, Canada, were found by Hunten and Shepherd (1954) to be consistent with a distribution of sodium atoms centred at a height of 85 km with a scale height of 7�5 km above and below the peak, the luminosity being due to resonance scattering of sunlight. By fitting Hunten's (1954) luminosity curve to experimental data obtained in Australia and Antarctica, O'Brien (1960) found a sodium layer height of90�5 km


2020 ◽  
Vol 3 (441) ◽  
pp. 36-43
Author(s):  
А. Leudanski ◽  
◽  
Y. Apimakh ◽  
А. Volnenko ◽  
D. Zhumadullayev ◽  
...  
Keyword(s):  

2020 ◽  
Vol 91 (7) ◽  
pp. 073103
Author(s):  
Yury V. Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter ◽  
Oleg A. Pimenov ◽  
Sergey A. Shlykov

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1192
Author(s):  
Ulrich David Jentschura

We propose a method by which one could use modified antimatter gravity experiments in order to perform a high-precision test of antimatter charge neutrality. The proposal is based on the application of a strong, external, vertically oriented electric field during an antimatter free-fall gravity experiment in the gravitational field of the Earth. The proposed experimental setup has the potential to drastically improve the limits on the charge-asymmetry parameter ϵ¯q of antimatter. On the theoretical side, we analyze possibilities to describe a putative charge-asymmetry of matter and antimatter, proportional to the parameters ϵq and ϵ¯q, by Lagrangian methods. We found that such an asymmetry could be described by four-dimensional Lorentz-invariant operators that break CPT without destroying the locality of the field theory. The mechanism involves an interaction Lagrangian with field operators decomposed into particle or antiparticle field contributions. Our Lagrangian is otherwise Lorentz, as well as PT invariant. Constraints to be derived on the parameter ϵ¯q do not depend on the assumed theoretical model.


2021 ◽  
Vol 11 (6) ◽  
pp. 2495
Author(s):  
Belén Ferrer ◽  
María-Baralida Tomás ◽  
David Mas

Some materials undergo hygric expansion when soaked. In porous rocks, this effect is enhanced by the pore space, because it allows water to reach every part of its volume and to hydrate most swelling parts. In the vicinity, this enlargement has negative structural consequences as adjacent elements support some compressions or displacements. In this work, we propose a normalized cross-correlation between rock surface texture images to determine the hygric expansion of such materials. We used small porous sandstone samples (11 × 11 × 30 mm3) to measure hygric swelling. The experimental setup comprised an industrial digital camera and a telecentric objective. We took one image every 5 min for 3 h to characterize the whole swelling process. An error analysis of both the mathematical and experimental methods was performed. The results showed that the proposed methodology provided, despite some limitations, reliable hygric swelling information by a non-contact methodology with an accuracy of 1 micron and permitted the deformation in both the vertical and horizontal directions to be explored, which is an advantage over traditional linear variable displacement transformers.


Author(s):  
Yu Zhao ◽  
Ulf Panzer ◽  
Stefan Bonn ◽  
Christian F. Krebs

AbstractSingle-cell biology is transforming the ability of researchers to understand cellular signaling and identity across medical and biological disciplines. Especially for immune-mediated diseases, a single-cell look at immune cell subtypes, signaling, and activity might yield fundamental insights into the disease etiology, mechanisms, and potential therapeutic interventions. In this review, we highlight recent advances in the field of single-cell RNA profiling and their application to understand renal function in health and disease. With a focus on the immune system, in particular on T cells, we propose some key directions of understanding renal inflammation using single-cell approaches. We detail the benefits and shortcomings of the various technological approaches outlined and give advice on potential pitfalls and challenges in experimental setup and computational analysis. Finally, we conclude with a brief outlook into a promising future for single-cell technologies to elucidate kidney function.


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