Excited ionic and neutral fragments produced by dissociation of the N2(+)* H band

N I and N II fluorescent radiation was observed when N2 was irradiated by undispersed synchrotron radiation with an upper energy limit of approximately 200 eV. The excited fragments originate from dissociation of a band of excited ionic states of N2 lying between 34.7 and 44 eV

Morphometric features and proximate body composition of rocky freshwater prawn (Caridina africana, Kingsley 1882) at Erin-Ijesa waterfalls, Osun State Nigeria

An investigation was conducted on the morphometric features and proximate body composition of rocky freshwater prawn, Caridina africana occurring at Erin-Ijesa Waterfalls in Osun State, Nigeria. The adult prawns were collected at the first layer of the Waterfalls using scoop nets and locally fabricated sieves because of the shallow nature of the water body and tiny size of the species. Morphometric features were measured using measuring board and Vernier calipers while the proximate analysis was determined by atomic absorption spectrophotometry in the laboratory. The morphometric variables placed the species correctly into the Infra order Caridea and family Atyidae because the first and second chelipeds were shorter than the remaining three pairs of walking legs. Male prawns were significantly bigger (p<0.05). than the females as revealed in the morphometric features. The proximate analysis showed that C. africana is composed of 58.79% protein, 5.42% lipid, 11.56% carbohydrate, 14.7% ash and 0.21 % crude fibre. The micro-nutrient composition included iron, zinc, copper, nickel and cadmium. The values for these nutrients make the study to suggest that C. africana could be a nutritive food bio-material for humans and other livestock nutrition especially the fin-fish aquaculture programme

Tunable refraction in a two dimensional quantum metamaterial

In this paper we consider a two-dimensional metamaterial comprising an array of qubits (two level quantum objects). Here we show that a two-dimensional quantum metamaterial may be controlled, e.g. via the application of a magnetic flux, so as to provide controllable refraction of an input signal. Our results are consistent with a material that could be quantum birefringent (beam splitter) or not dependent on the application of this control parameter. We note that quantum metamaterials as proposed here may be fabricated from a variety of current candidate technologies from superconducting qubits to quantum dots. Thus the ideas proposed in this work would be readily testable in existing state of the art laboratories.Comment: 4 pages, 2 figure

Spin injection in Silicon at zero magnetic field

In this letter, we show efficient electrical spin injection into a SiGe based \textit{p-i-n} light emitting diode from the remanent state of a perpendicularly magnetized ferromagnetic contact. Electron spin injection is carried out through an alumina tunnel barrier from a Co/Pt thin film exhibiting a strong out-of-plane anisotropy. The electrons spin polarization is then analysed through the circular polarization of emitted light. All the light polarization measurements are performed without an external applied magnetic field \textit{i.e.} in remanent magnetic states. The light polarization as a function of the magnetic field closely traces the out-of-plane magnetization of the Co/Pt injector. We could achieve a circular polarization degree of the emitted light of 3 % at 5 K. Moreover this light polarization remains almost constant at least up to 200 K.Comment: accepted in AP

The Effect of ICT on Federal Radio Cooperation of Nigeria

Information and Communication Technologies (ICT) developments have existed in Nigeria with a significant growth over the past decade. This paper looks at the role of emerging ICT on the general operations of Federal Radio Cooperation of Nigeria in achieving an objective of information decimation. This study shows that the ICT facilities have brought significant improvement to the FRCN service delivery which is important factor for growth and development in the society even though there are still some problems militating the use of ICT in the FRCN. The highest factor militating against the use of ICT is shortage of power supply followed by poor funding and lastly poor network facilities

Ordering intermetallic alloys by ion irradiation: a way to tailor magnetic media

Combining He ion irradiation and thermal mobility below 600K, we both trigger and control the transformation from chemical disorder to order in thin films of an intermetallic ferromagnet (FePd). Kinetic Monte Carlo simulations show how the initial directional short range order determines order propagation. Magnetic ordering perpendicular to the film plane was achieved, promoting the initially weak magnetic anisotropy to the highest values known for FePd films. This post-growth treatment should find applications in ultrahigh density magnetic recording.Comment: 7 pages, 3 Figure

Assessing the Impact of Pre-gpm Microwave Precipitation Observations in the Goddard WRF Ensemble Data Assimilation System

The forthcoming Global Precipitation Measurement (GPM) Mission will provide next generation precipitation observations from a constellation of satellites. Since precipitation by nature has large variability and low predictability at cloud-resolving scales, the impact of precipitation data on the skills of mesoscale numerical weather prediction (NWP) is largely affected by the characterization of background and observation errors and the representation of nonlinear cloud/precipitation physics in an NWP data assimilation system. We present a data impact study on the assimilation of precipitation-affected microwave (MW) radiances from a pre-GPM satellite constellation using the Goddard WRF Ensemble Data Assimilation System (Goddard WRF-EDAS). A series of assimilation experiments are carried out in a Weather Research Forecast (WRF) model domain of 9 km resolution in western Europe. Sensitivities to observation error specifications, background error covariance estimated from ensemble forecasts with different ensemble sizes, and MW channel selections are examined through single-observation assimilation experiments. An empirical bias correction for precipitation-affected MW radiances is developed based on the statistics of radiance innovations in rainy areas. The data impact is assessed by full data assimilation cycling experiments for a storm event that occurred in France in September 2010. Results show that the assimilation of MW precipitation observations from a satellite constellation mimicking GPM has a positive impact on the accumulated rain forecasts verified with surface radar rain estimates. The case-study on a convective storm also reveals that the accuracy of ensemble-based background error covariance is limited by sampling errors and model errors such as precipitation displacement and unresolved convective scale instability