Bubble memory module

Design, fabrication and test of partially populated prototype recorder using 100 kilobit serial chips is described. Electrical interface, operating modes, and mechanical design of several module configurations are discussed. Fabrication and test of the module demonstrated the practicality of multiplexing resulting in lower power, weight, and volume. This effort resulted in the completion of a module consisting of a fully engineered printed circuit storage board populated with 5 of 8 possible cells and a wire wrapped electronics board. Interface of the module is 16 bits parallel at a maximum of 1.33 megabits per second data rate on either of two interface buses

The Magnetic Sensitivity of the Ba II D1 and D2 Lines of the Fraunhofer Spectrum

The physical interpretation of the spectral line polarization produced by the joint action of the Hanle and Zeeman effects offers a unique opportunity to obtain empirical information about hidden aspects of solar and stellar magnetism. To this end, it is important to achieve a complete understanding of the sensitivity of the emergent spectral line polarization to the presence of a magnetic field. Here we present a detailed theoretical investigation on the role of resonance scattering and magnetic fields on the polarization signals of the Ba II D1 and D2 lines of the Fraunhofer spectrum, respectively at 4934 \AA\ and 4554 \AA. We adopt a three-level model of Ba II, and we take into account the hyperfine structure that is shown by the $^{135}$Ba and $^{137}$Ba isotopes. Despite of their relatively small abundance (18%), the contribution coming from these two isotopes is indeed fundamental for the interpretation of the polarization signals observed in these lines. We consider an optically thin slab model, through which we can investigate in a rigorous way the essential physical mechanisms involved (resonance polarization, Zeeman, Paschen-Back and Hanle effects), avoiding complications due to radiative transfer effects. We assume the slab to be illuminated from below by the photospheric solar continuum radiation field, and we investigate the radiation scattered at 90 degrees, both in the absence and in the presence of magnetic fields, deterministic and microturbulent. We show in particular the existence of a differential magnetic sensitivity of the three-peak Q/I profile that is observed in the D2 line in quiet regions close to the solar limb, which is of great interest for magnetic field diagnostics.Comment: 40 pages, 1 table and 19 figures. Accepted for publication in The Astrophysical Journal (ApJ

Towards Quantitative Classification of Folded Proteins in Terms of Elementary Functions

A comparative classification scheme provides a good basis for several approaches to understand proteins, including prediction of relations between their structure and biological function. But it remains a challenge to combine a classification scheme that describes a protein starting from its well organized secondary structures and often involves direct human involvement, with an atomary level Physics based approach where a protein is fundamentally nothing more than an ensemble of mutually interacting carbon, hydrogen, oxygen and nitrogen atoms. In order to bridge these two complementary approaches to proteins, conceptually novel tools need to be introduced. Here we explain how the geometrical shape of entire folded proteins can be described analytically in terms of a single explicit elementary function that is familiar from nonlinear physical systems where it is known as the kink-soliton. Our approach enables the conversion of hierarchical structural information into a quantitative form that allows for a folded protein to be characterized in terms of a small number of global parameters that are in principle computable from atomary level considerations. As an example we describe in detail how the native fold of the myoglobin 1M6C emerges from a combination of kink-solitons with a very high atomary level accuracy. We also verify that our approach describes longer loops and loops connecting $\alpha$-helices with $\beta$-strands, with same overall accuracy.Comment: 3 figure

The long period eccentric orbit of the particle accelerator HD167971 revealed by long baseline interferometry

Using optical long baseline interferometry, we resolved for the first time the two wide components of HD167971, a candidate hierarchical triple system known to efficiently accelerate particles. Our multi-epoch VLTI observations provide direct evidence for a gravitational link between the O8 supergiant and the close eclipsing O + O binary. The separation varies from 8 to 15 mas over the three-year baseline of our observations, suggesting that the components evolve on a wide and very eccentric orbit (most probably e>0.5). These results provide evidence that the wide orbit revealed by our study is not coplanar with the orbit of the inner eclipsing binary. From our measurements of the near-infrared luminosity ratio, we constrain the spectral classification of the components in the close binary to be O6-O7, and confirm that these stars are likely main-sequence objects. Our results are discussed in the context of the bright non-thermal radio emission already reported for this system, and we provide arguments in favour of a maximum radio emission coincident with periastron passage. HD167971 turns out to be an efficient O-type particle accelerator that constitutes a valuable target for future high angular resolution radio imaging using VLBI facilities.Comment: 8 pages, including 4 figures, accepted by Monthly Notices of the Royal Astronomical Societ

A model to assess customer alignment through customer experience concepts

Business and Information Technology Alignment (BITA) has been one of the main concerns of IT and Business executives and directors due to its importance to overall company performance, especially today in the age of digital transformation. For BITA has been developed several models which in general has focused in the implementation of alignment strategies for the internal operation of the organizations and in the measurement of this internal alignment, but, there is still a big gap in measurement models of the alignment with the external environment of the organizations. In this paper is presented the design and application of a maturity measurement model for BITA with the customers, where the customers are actors of the external environment of the companies. The proposed model involves evaluation criteria and business practices which the companies ideally do for improve the relationship with their customers.Comment: 12 pages, Preprint version, BIS 2019 International Workshops, Seville, Spain, June 26 to 28, 2019, Revised Paper

The 10 to the 8th power bit solid state spacecraft data recorder

The results are summarized of a program to demonstrate the feasibility of Bubble Domain Memory Technology as a mass memory medium for spacecraft applications. The design, fabrication and test of a partially populated 10 to the 8th power Bit Data Recorder using 100 Kbit serial bubble memory chips is described. Design tradeoffs, design approach and performance are discussed. This effort resulted in a 10 to the 8th power bit recorder with a volume of 858.6 cu in and a weight of 47.2 pounds. The recorder is plug reconfigurable, having the capability of operating as one, two or four independent serial channel recorders or as a single sixteen bit byte parallel input recorder. Data rates up to 1.2 Mb/s in a serial mode and 2.4 Mb/s in a parallel mode may be supported. Fabrication and test of the recorder demonstrated the basic feasibility of Bubble Domain Memory technology for such applications. Test results indicate the need for improvement in memory element operating temperature range and detector performance

Detection of X-ray Emission from the Very Old Pulsar J0108-1431

PSR J0108-1431 is a nearby, 170 Myr old, very faint radio pulsar near the "pulsar death line" in the P-Pdot diagram. We observed the pulsar field with the Chandra X-ray Observatory and detected a point source (53 counts in a 30 ks exposure, energy flux (9+/-2)\times 10^{-15} ergs cm^{-2} s^{-1} in the 0.3-8 keV band) close to the radio pulsar position. Based on the large X-ray/optical flux ratio at the X-ray source position, we conclude that the source is the X-ray counterpart of PSR J0108-1431.The pulsar spectrum can be described by a power-law model with photon index Gamma \approx 2.2 and luminosity L_{0.3-8 keV} \sim 2\times 10^{28} d_{130}^2 ergs s^{-1}, or by a blackbody model with the temperature kT\approx 0.28 keV and bolometric luminosity L_{bol} \sim 1.3\times 10^{28} d_{130}^2 ergs s^{-1}, for a plausible hydrogen column density NH = 7.3\times 10^{19} cm^{-2} (d_{130}=d/130 pc). The pulsar converts \sim 0.4% of its spin-down power into the X-ray luminosity, i.e., its X-ray efficiency is higher than for most younger pulsars. From the comparison of the X-ray position with the previously measured radio positions, we estimated the pulsar proper motion of 0.2 arcsec yr^{-1} (V_\perp \sim 130 d_{130} km s^{-1}), in the south-southeast direction.Comment: 8 pages, 9 figures, accepted to ApJ; minor revisions in Sections 2.2 and 3.

Intersubband magnetophonon resonances in quantum cascade structures

We report on our magnetotransport measurements of GaAs/GaAlAs quantum cascade structures in a magnetic field of up to 62 T. We observe novel quantum oscillations in tunneling current that are periodic in reciprocal magnetic field. We explain these oscillations as intersubband magnetophonon resonance due to electron relaxation by emission of either single optical or acoustic phonons. Our work also provides a non-optical in situ measurement of intersubband separations in quantum cascade structures.Comment: 5 pages, 4 figure