The Superconducting Gravimeter CD-034 at Moxa Observatory: More than 20 Years of Scientific Experience and a Reanimation

In this work, advanced methods and processing schemes for the analysis of data from a Superconducting Gravimeter (SG) will be introduced and their relevance on acquired data proved. The SG CD-034 was installed on Easter of 1999 in the Geodynamic Observatory Moxa of the Friedrich Schiller University Jena, Germany. Initially, the quality of the recorded data was examined, spectra for the detection of the parasitic modes were calculated and the calibration values for the two sensors were determined. Ever since very high-quality gravity data of this SG and most of the other worldwide SGs were made available through the storage archive of the Global Geodynamics Project (GGP later changed to IGETS, International Geodynamics and Earth Tide Service) for global scientific investigations at that time. SG’s such as the one in Moxa (Germany) still deliver significant scientific value for global gravitational field studies as well as for regional/local studies which will be shortly reviewed. Examples are the detection of polar motion, the influence of continental water loading in general and in particular river basin loads, the gravimetric effect of North Sea storm surges and the study of hydro-gravimetric signals, which could be compared with satellite observations and global hydraulic models. The long-term, low-noise operation of complex SG’s requires some effort on maintenance. In order to evaluate the correct operation of the SG, new data processing steps were introduced to assist in the analysis of the data in case of issues with the instrumentation. For example, in 2012/2013 and 2020/2021 severe interference in the gravimeter electronics in Moxa led to a significant loss of data. In both cases, however, the cause could be determined, and the corresponding electronic components renewed. Since July 2021, the SG in Moxa registers again with high data quality comparable or slightly better than before the incident. Initial tests and tidal analyses confirm the validity of the old calibration factors, and the authors now look forward to the re-established long-term recording with excitement and confidence

“I’m Sorry”: An original song for voice and chordal accompaniment

Below is an original song written for mezzo-soprano voice and accompaniment. The purpose of this article is to provide information on the songwriting process that I used by discussing the melody, harmony, and lyrics and showing how they were developed and completed. This article discusses and defines musical terms for musicians and non-musicians alike to show why certain decisions were made. I begin by discussing the lyrics of the song and their meaning. I will reference methods included in J. Perricone’s book Great Songwriting Techniques to discuss how the chords and melodies relate to the lyrics. The song is notated below in the form of a lead sheet so that it could be performed accurately without an overabundance of detail. Normally, a lead sheet such as this provides only melodic and harmonic information with very little background provided. Though I do provide information on how the song is to be performed, the lead sheet does not have this information. This means the performer must use context to effectively convey the song to the listener. The performer must use the lyrics to reference what the song is about, as well as the chords and melody to identify the overall tonality of the song. The instrumentation is then left for the performer to decide based on their ability and the ideas and emotion they want to convey

Dark-time decay of the retrieval efficiency of light stored as a Rydberg excitation in a noninteracting ultracold gas

We study the dark-time decay of the retrieval efficiency for light stored in a Rydberg state in an ultracold gas of $^{87}$Rb atoms based on electromagnetically induced transparency (EIT). Using low atomic density to avoid dephasing caused by atom-atom interactions, we measure a $1/e$ time of 30 $\mu$s for the $80S$ state in free expansion. One of the dominant limitations is the combination of photon recoil and thermal atomic motion at 0.2 $\mu$K. If the 1064-nm dipole trap is left on, then the $1/e$ time is reduced to 13 $\mu$s, in agreement with a model taking differential light shifts and gravitational sag into account. To characterize how coherent the retrieved light is, we overlap it with reference light and measure the visibility $V$ of the resulting interference pattern, obtaining $V> 90\%$ for short dark time. Our experimental work is accompanied by a detailed model for the dark-time decay of the retrieval efficiency of light stored in atomic ensembles. The model is generally applicable for photon storage in Dicke states, such as in EIT with $\Lambda$-type or ladder-type level schemes and in Duan-Lukin-Cirac-Zoller single-photon sources. The model includes a treatment of the dephasing caused by thermal atomic motion combined with net photon recoil, as well as the influence of trapping potentials. It takes into account that the signal light field is typically not a plane wave. The model maps the retrieval efficiency to single-atom properties and shows that the retrieval efficiency is related to the decay of fringe visibility in Ramsey spectroscopy and to the spatial first-order coherence function of the gas.Comment: List of changes: (i) The role of separable and entangled states was clarified. In the process, a new appendix C was added. (ii) More detail was added in the supplemental material in sections II.E and II.F, that discuss the relation to Ramsey spectroscopy and to the spatial coherence function. (iii) A new figure 1 was added. (iv) Various smaller revisions were mad

Evidence for a change in the nuclear mass surface with the discovery of the most neutron-rich nuclei with 17<Z <25

The results of measurements of the production of neutron-rich nuclei by the fragmentation of a 76-Ge beam are presented. The cross sections were measured for a large range of nuclei including fifteen new isotopes that are the most neutron-rich nuclides of the elements chlorine to manganese (50-Cl, 53-Ar, 55,56-K, 57,58-Ca, 59,60,61-Sc, 62,63-Ti, 65,66-V, 68-Cr, 70-Mn). The enhanced cross sections of several new nuclei relative to a simple thermal evaporation framework, previously shown to describe similar production cross sections, indicates that nuclei in the region around 62-Ti might be more stable than predicted by current mass models and could be an indication of a new island of inversion similar to that centered on 31-Na.Comment: 4 pages, 3 figures, to be published in Physical Review Letters, 200

Bimetallic Two-Dimensional Metal–Organic Frameworks for the Chemiresistive Detection of Carbon Monoxide

This paper describes the demonstration of a series of heterobimetallic, isoreticular 2D conductive metal–organic frameworks (MOFs) with metallophthalocyanine (MPc, M=Co and Ni) units interconnected by Cu nodes towards low-power chemiresistive sensing of ppm levels of carbon monoxide (CO). Devices achieve a sub-part-per-million (ppm) limit of detection (LOD) of 0.53 ppm toward CO at a low driving voltage of 0.1 V. MPc-based Cu-linked MOFs can continuously detect CO at 50 ppm, the permissible exposure limit required by the Occupational Safety and Health Administration (OSHA), for multiple exposures, and realize CO detection in air and in humid environment. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), density functional theory (DFT) calculations, and comparison experiments suggest the contribution of Cu nodes to CO binding and the essential role of MPc units in tuning and amplifying the sensing response

Beta-delayed proton emission in the 100Sn region

Beta-delayed proton emission from nuclides in the neighborhood of 100Sn was studied at the National Superconducting Cyclotron Laboratory. The nuclei were produced by fragmentation of a 120 MeV/nucleon 112Sn primary beam on a Be target. Beam purification was provided by the A1900 Fragment Separator and the Radio Frequency Fragment Separator. The fragments of interest were identified and their decay was studied with the NSCL Beta Counting System (BCS) in conjunction with the Segmented Germanium Array (SeGA). The nuclei 96Cd, 98Ing, 98Inm and 99In were identified as beta-delayed proton emitters, with branching ratios bp = 5.5(40)%, 5.5+3 -2%, 19(2)% and 0.9(4)%, respectively. The bp for 89Ru, 91,92Rh, 93Pd and 95Ag were deduced for the first time with bp = 3+1.9 -1.7%, 1.3(5)%, 1.9(1)%, 7.5(5)% and 2.5(3)%, respectively. The bp = 22(1)% for 101Sn was deduced with higher precision than previously reported. The impact of the newly measured bp values on the composition of the type-I X-ray burst ashes was studied.Comment: 15 pages, 14 Figures, 4 Table