1,350 research outputs found

    Copolymerazaion of N-vinyl-2-pyrrolidon with Acrylic Acid and Methylmethacrylate

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    Low conversion copolymerization of N-vinyl-2-pyrrolidon M.W = (111.14) VP (monomer-1) has been conducted with acrylic acid AA and methymethacrylate MMA in ethanol at 70ºC , using Benzoyl peroxide BPO as initiator . The copolymer composition has been determined by elemental analysis. The monomer reactivity ratios have been calculated by the Kelen-Tudos and Finman-Ross graphical procedures . The derived reactivity ratios (r1 , r2 ) are : (0.51 , 4.85) for (VP / AA ) systems and (0.34 , 7.58) for (VP , MMA) systems , and found the reactivity ratios of the monomer AA , MMA is mor than the monomer VP in the copolymerization of (VP / AA) and (VP /MMA) systems respectly . The reactivity ratios values were used for microstructures calculation

    ASSESSMENT OF SCARCITY OF WOODWORK ARTISAN IN BUILDING CONSTRUCTION IN KWARA STATE, NIGERIA

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    Woodwork artisanal scarcity is at an alarming rate in Nigeria and in Kwara state in particular. The reason being that most of the available woodwork artisans lack adequate skills demanded quality Building Construction. Generally, the issue of woodwork artisanal scarcity is not a current one as it dates as far back as the two World Wars. This study is on the causes of the observed scarcity of woodwork artisans in Nigeria and Kwara state in particular. The objectives of the study were to identify the factors increasing woodwork artisanal scarcity in Kwara state, its effect on Kwara state economy and the possible remedies. The study employed the use of descriptive survey design which involves the use of a structured questionnaire to collect data from 25 contractors and 35 woodwork artisans in carpentry and joinery. There was no sampling because the population is manageable, hence, the entire population was used. Mean ratings were used to answer research questions. The findings show that major factors causing the scarcity of woodwork artisans include; fluctuating payment, low remuneration, low motivation, lack of interest to take-up woodwork trade by youth, technological advancements in tools, equipment and working process. It also identified the effects of scarcity of woodwork artisan on Kwara state economy. Based on the finding of the study, it was recommended that the Carpentry and Joinery Union of Kwara state should encourage the welfare of its members in order to improve the issues raised by this study

    X-Ray Spectral Study of AGN Sources Content in Some Deep Extragalactic XMM-Newton Fields

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    We undertake a spectral study of a sample of bright X-ray sources taken from six XMM-Newton fields at high galactic latitudes, where AGN are the most populous class. These six fields were chosen such that the observation had an exposure time more than 60 ksec, had data from the EPIC-pn detector in the full-Frame mode and lying at high galactic latitude b>25o|b| > 25^o . The analysis started by fitting the spectra of all sources with an absorbed power-law model, and then we fitted all the spectra with an absorbed power-law with a low energy black-body component model.The sources for which we added a black body gave an F-test probability of 0.01 or less (i.e. at 99% confidence level), were recognized as sources that display soft excess. We perform a comparative analysis of soft excess spectral parameters with respect to the underlying power-law one for sources that satisfy this criterion. Those sources, that do not show evidence for a soft excess, based on the F-test probability at a 99% confidence level, were also fitted with the absorbed power-law with a low energy black-body component model with the black-body temperature fixed at 0.1 and 0.2 keV. We establish upper limits on the soft excess flux for those sources at these two temperatures. Finally we have made use of Aladdin interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED) to identify the X-ray sources in our sample. For those sources which are identified in the NED catalogue, we make a comparative study of the soft excess phenomenon for different types of systems
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