14,987 research outputs found

    Evidence for inhomogeneous thermal sources of two similar solar spike event of 1978, May 5 and December 4

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    Two short duration single spike events of 1978 May 5 and December 4 exhibit similar time profiles in the microwave and hard X-ray ranges, indicating emission from compact sources. Microwave spectral observations exhibit inhomogeneities present in the source parameters. The existence of fine time structures in the microwave time profiles at 10.4 GHz from Berne are interpreted as a signature of the dynamics of a disturbance travelling through the souce at the ion-sound speed. Stereoscopic observations with the hard X-ray detector on the solar orbiter, Helios-2, and the Berne microwave antennae do not indicate any time lag or differences in the time profiles during the impulsive phase. This is taken as evidence for the absence of directionality of emission making beam models unlikely for short duration single spike events

    Utilization of landmark data in attitude/orbit determination

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    A mathematical model is reported for determination of satellite position, velocity, and attitude using landmark coordinates as observables. This model, although developed with respect to earth stabilized missions, Tiros-N and Nimbus-G in particular, is applicable to any earth stabilized satellite in general

    Determining the number of hidden units in multi-layer perceptrons using F-ratios

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    The hidden units in multi-layer perceptrons are believed to act as feature extractors. In other words, the outputs of the hidden units represent the features in a more traditional statistical classification paradigm. This viewpoint offers a statistical, objective approach to determining the optimal number of hidden units required. This approach is based on an F-ratio test, and proceeds in an iterative fashion. The method and its application to simulated time-series data are presented

    Foundation System for “ Akshardham” to Control Deformations Related to Probable Liquefaction

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    The paper presents a system of foundation for 38.0 m high monumental unique structure “ Akhsardham” on bank of “Yamuna” river at Noida ,New Delhi(India). The design is outcome of interaction of ideological requirements of Architects, Seismologist, Geotechnical and Structural engineers, as well as those empirical rules of Vastu- Shastra for religious places. The structure is typical flexible stone monument. It is located on alluvium of “Yamuna” river in seismic Zone IV of Bureau of Indian standards. The preliminary exploration report indicated liquefaction potential and suggested deep foundations. The engineering priests decided against use of steel for the structure expected to exist for 2-3 countries. The authors reviewed soil report, got quick check tests to for analysis of probability of liquefaction. Based on this studies and deliberations with the above agencies evolved economical massive foundation to fulfill requirements without compromising safety. The construction over foundation is in full swing

    Isobutanol production from cellobionic acid in Escherichia coli.

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    BackgroundLiquid fuels needed for the global transportation industry can be produced from sugars derived from plant-based lignocellulosics. Lignocellulosics contain a range of sugars, only some of which (such as cellulose) have been shown to be utilizable by microorganisms capable of producing biofuels. Cellobionic acid makes up a small but significant portion of lignocellulosic degradation products, and had not previously been investigated as an utilizable substrate. However, aldonic acids such as cellobionic acid are the primary products of a promising new group of lignocellulosic-degrading enzymes, which makes this compound group worthy of study. Cellobionic acid doesn't inhibit cellulose degradation enzymes and so its inclusion would increase lignocellulosic degradation efficiency. Also, its use would increase overall product yield from lignocellulose substrate. For these reasons, cellobionic acid has gained increased attention for cellulosic biofuel production.ResultsThis study describes the discovery that Escherichia coli are naturally able to utilize cellobionic acid as a sole carbon source with efficiency comparable to that of glucose and the construction of an E. coli strain able to produce the drop-in biofuel candidate isobutanol from cellobionic acid. The gene primarily responsible for growth of E. coli on cellobionic acid is ascB, a gene previously thought to be cryptic (expressed only after incurring specific mutations in nearby regulatory genes). In addition to AscB, the ascB knockout strain can be complemented by the cellobionic acid phosphorylase from the fungus Neurospora crassa. An E. coli strain engineered to express the isobutanol production pathway was successfully able to convert cellobionic acid into isobutanol. Furthermore, to demonstrate potential application of this strain in a sequential two-step bioprocessing system, E. coli was grown on hydrolysate (that was degraded by a fungus) and was successfully able to produce isobutanol.ConclusionsThese results demonstrate that cellobionic acid is a viable carbon source for biofuel production. This work suggests that with further optimization, a bacteria-fungus co-culture could be used in decreased-cost biomass-based biofuel production systems

    Two Years of Brexit: the Reverse-Domino Effect and the Woes of the Overseas Territories

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    With now less than 100 days left until the boisterous Brexit, the United Kingdom (UK) is still in a puddle, over how to leave the European Union on its terms. The conscious secession is shaping up to be far more tumultuous than stipulated and the next two years will be nothing short of a battle for Britain. What has become of the economic situation in the UK? Why isn't there a spiraling domino effect in the European Union post-Brexit as misconstrued by analysts? Is Brexit a problem to a solution? How does Brussels look at it
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