Laser Ranging Interferometer on GRACE Follow-On: Current Status

Author(s):  
Vitali Müller ◽  

<p>The GRACE Follow-On satellites were launched on 22<sup>nd</sup> May 2018 to continue the measurement of Earth’s gravity field from the GRACE satellites (2002-2017). A few weeks later, an inter-satellite laser link was established with the novel Laser Ranging Interferometer (LRI), which offers an additional measurement of the inter-satellite range next to the one provided by the conventional microwave ranging instrument. The LRI is the first optical interferometer in space between orbiters, which has demonstrated to measure distance variations with a noise below 1 nm/rtHz at Fourier frequencies around 1 Hz, well below the requirement of 80 nm/rtHz.</p><p>In this talk, we provide an overview on the LRI and present the current status and results regarding the characterization of the instrument. We will address the scale factor, which is needed to convert the phase measurements to a displacement, and the removal of phase jumps that are correlated to attitude thruster activations. Moreover, the results comprise the coupling of attitude variations into the measured range, which is determined by means of the center-of-mass calibration maneuvers. This coupling is expected to be one of the major error sources at low frequencies, however, it is not directly apparent due to the large gravity signal.</p><p>We conclude with some learned lessons and potential modifications of the interferometry for future geodetic missions.</p>


2021 ◽  
Author(s):  
Vitali Müller ◽  
Malte Misfeldt ◽  
Laura Müller ◽  
Henry Wegener ◽  
Gerhard Heinzel

<p>The GRACE Follow-On satellites were launched <span>on</span> <span>22</span>nd May <span>2018</span> <span>to</span> <span>continue</span> the measurement of Earth’s gravity field from the GRACE satellites (<span>2002</span>-<span>2017</span>). A few weeks <span>later</span>, <span>an</span> inter-satellite laser link was established with the novel Laser Ranging Interferometer (LRI), which offers <span>an</span> additional measurement of the inter-satellite <span>range</span> <span>next</span> <span>to</span> the one provided by the conventional microwave ranging instrument. The LRI <span>is</span> the <span>first</span> optical interferometer in space between orbiters, which <span>has</span> demonstrated <span>to</span> measure distance variations with <span>a</span> noise below <span>1</span> <span>nm</span>/√Hz at Fourier frequencies around <span>1</span> Hz, well below the requirement of <span>80</span> <span>nm</span>/√Hz. In this talk, we provide <span>an</span> overview <span>on</span> the LRI, present the current status of the instrument <span>and</span> show results regarding the characterization of the instrument. We will address impulse events that are apparent in the accelerometer <span>and</span> LRI <span>range</span> acceleration data, most of which are expected <span>to</span> <span>be</span> micro-meteorites. Other short-term disturbances in the ranging data will <span>be</span> addressed <span>as</span> well. We conclude with some learned lessons <span>and</span> potential modifications of the interferometry <span>for</span> future geodetic missions.</p>



JURNAL BASIS ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 159
Author(s):  
Ellif Shiffiyn Khairaa

This researched aims to analyze the characterization of Margio as the main character of the novel entitled Lelaki Harimau by Eka Kurniawan. This study used narrative structure by Gerard Genette which focused on frequency concept to analyze the characterization. The descriptive qualitative method used to reveal and make a deep analysis of the characterization of Margio. The data is taken by reread the novel and written the quotations of the dialogue which focused on the characterization of Margio. The result of this study is Margio has strong characterization and he is the one who connected to the other characters in the novel. He is known as a lovable, obedient to their parents, and a strong man. The moral value of this novel is the key to a perfect family is the good communication of each member of the family. This study is important in how we learned the complexity of human relations, especially in the family.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Ghafuri ◽  
Zeinab Tajik ◽  
Nastaran Ghanbari ◽  
Peyman Hanifehnejad

AbstractIn this work, graphitic carbon nitride-supported l-arginine (g-C3N4@l-arginine) nanocatalyst was synthesized and evaluated using FT-IR, EDX, XRD, TGA, and FESEM analyses. The performance of the prepared nanocatalyst was examined in the synthesis of 1,4-dihydropyridine, 4H-chromene, and 2,3-dihydro quinazoline derivatives. The novel g-C3N4@l-arginine nanocatalyst showed high thermal stability, easy separation from reaction media, the capability to be used in various multicomponent reactions, and acceptable reusability.



Heritage ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 4629-4646
Author(s):  
Antonio Formisano ◽  
Generoso Vaiano

The safety of the built heritage of our cities towards environmental factors and seismic actions is a pressing need for designers and researchers. The actual trend is to setup effective solutions to reduce thermal dispersions through the building envelope. Contrarily, combined systems able to enhance the resistance of constructions to earthquakes, on the one hand, and, on the other hand, to increase the energetic efficiency of existing buildings are scarcely diffused on the market and are rarely investigated in the scientific literature. In this framework, the seismic design of the new envelope DUO system for seismic-environmental requalification of existing masonry constructions is illustrated in the present paper with reference to a case study in the Neapolitan area. After the geometrical and mechanical characterization of the investigated building is performed, an FEM model of the masonry construction is setup by the SAP2000 analysis program, which has allowed performing pushover analyses. Based on the non-linear seismic response of the construction, an appropriate upgrading design mainly based on the innovative seismic envelope DUO system has been made. The static non-linear analyses applied to the upgraded FEM model of the building have shown a clear increase in performance in terms of strength, stiffness and ductility, thus confirming the effectiveness of the proposed envelope system.





2020 ◽  
pp. 182-197
Author(s):  
Agnieszka Goral

The aim of the article is to analyse the elements of folk poetics in the novel Pleasant things. Utopia by T. Bołdak-Janowska. The category of folklore is understood in a rather narrow way, and at the same time it is most often used in critical and literary works as meaning a set of cultural features (customs and rituals, beliefs and rituals, symbols, beliefs and stereotypes) whose carrier is the rural folk. The analysis covers such elements of the work as place, plot, heroes, folk system of values, folk rituals, customs, and symbols. The description is conducted based on the analysis of source material as well as selected works in the field of literary text analysis and ethnolinguistics. The analysis shows that folk poetics was creatively associated with the elements of fairy tales and fantasy in the studied work, and its role consists of – on the one hand – presenting the folk world represented and – on the other – presenting a message about the meaning of human existence.



Author(s):  
Charles Dickens ◽  
Dennis Walder

Dombey and Son ... Those three words conveyed the one idea of Mr. Dombey's life. The earth was made for Dombey and Son to trade in, and the sun and moon were made to give them light.' The hopes of Mr Dombey for the future of his shipping firm are centred on his delicate son Paul, and Florence, his devoted daughter, is unloved and neglected. When the firm faces ruin, and Dombey's second marriage ends in disaster, only Florence has the strength and humanity to save her father from desolate solitude. This new edition contains Dickens's prefaces, his working plans, and all the original illustrations by ‘Phiz’. The text is that of the definitive Clarendon edition. It has been supplemented by a wide-ranging Introduction, highlighting Dickens's engagement with his times, and the touching exploration of family relationships which give the novel added depth and relevance.



2006 ◽  
Vol 50 (4) ◽  
pp. 1228-1237 ◽  
Author(s):  
Nagraj Mani ◽  
Christian H. Gross ◽  
Jonathan D. Parsons ◽  
Brian Hanzelka ◽  
Ute Müh ◽  
...  

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.



2020 ◽  
Vol 11 (45) ◽  
pp. 12233-12248
Author(s):  
Haru Hirai ◽  
Shun Ito ◽  
Shinjiro Takano ◽  
Kiichirou Koyasu ◽  
Tatsuya Tsukuda

This perspective summarizes the current status and emerging trends in synthesis and characterization of ligand-protected gold/silver superatoms.



HLA ◽  
2021 ◽  
Author(s):  
Maria Loginova ◽  
Olga Makhova ◽  
Daria Smirnova ◽  
Igor Paramonov ◽  
Maksim Zarubin


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