999 research outputs found

    Age and growth analysis of the fish Mastacembelus armatus (Lacepede) from River Nayar, Garhwal Himalaya, Uttarakhand

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    The ability to age fish accurately is essential in understanding the dynamics of fish population. Age and growth determination in Mastacembelus armatus was assessed by the scale method which was verified by the length-frequency distribution method. The scales were small, elongated and the focus was shifted slightly uppish from the centre. The fish length and scale radius relationship was found linear (Scale radius = 6.974 + 0.452 Fish length; r = 0.9746) and authenticated the age analysis. Back calculation method was used to find out the size of fish at annulus formation, which confirmed four age rings in M. armatus  at the size of 14.07±0.92,  26.05±4.99,  37.96± 2.59  and  48.48±6.06 cm respectively. First two age rings were observed in the fish length group 30-40 cm, the third ring was observed in 40-50 cm and the fourth ring in 50-60 cm length group. The finding was dully validated by length-frequency distribution method. The growth annual increment (h) of M. armatus shows that the length increment was 14.07, 13.32, 11.91 and 10.52 cm during 1st, 2nd, 3rd and 4th year respectively. It shows that the fish grows continuously during its entire life period. The average growth (? h) was observed as 12.12 cm. annually. The assessment of age and growth rate of fish is a prerequisite to generate the information on recruitment, longevity and fluctuations in fishery caused by various year classes which is an important tool for rational exploitation of fish stock

    Analysis and interdependence of morphometric characters in the Hill stream fish Mastacembelus armatus (Lacepede) from Garhwal Himalaya

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    Study of morphometric characters is generally carried out for species identification in fish biology. It includes the measurements of all body lengths and their inter relationships in terms of ratios and percentages to the independent lengths (Total length, standard length and head length). Present paper deals with the analysis of various morphometric characters with species characteristics in Mastacembelus armatus (Lacepede),  which is one of the most important eel like hillstream fish belonging to order Mastacembeliformes and family Mastacembelidae from river Western Nayar (290 45’ to 300 15’ latitude and 780 34’ to 790 12’ longitude ). Total length, standard length and head lengths were considered as an independent variables in ratio of which other lengths (caudal length, pre orbital length, post orbital length, maximum body depth, snout length and eye diameter) were analysed. The maximum size of fish was observed as 60 cm and the minimum being 10 cm. By using regression and correlation analysis, the modelling of data is presented to find out their interrelationship. The closest correlation was in between total length and standard length (r= 0.999) and the farthest between total length and caudal length ( r= 0.878). The linearity of regression was tested by the analysis of variance (ANOVA) which showed that all the relationships were significant at the level of 5 % significance. The multivariate analysis was also done by using cluster technique which sowed except caudal length rest all characters were forming a close cluster

    Kesan pemendapan elektroforesis gam arab terhadap kakisan SS316 L dalam persekitaran asid

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    Keluli tahan karat jenis 316L (SS316L) adalah satu logam yang berpotensi untuk digunakan sebagai plat dwikutub bagi sel fuel membran pertukaran proton (PEMFC). SS316L memiliki sifat kekonduksian elektrik dan kepasifan yang baik, namun jika digunakan pada sekitaran asid (pH 3-6), sifat pelarutan SS316L akan menyebabkan mudah terhakis. Dalam kajian ini, salutan perencat kakisan hijau gam arab dengan kaedah pemendapan elektroforesis (EPD) digunakan untuk mengurangkan kakisan plat SS316L. Hasil analisis scaning electron microscope (SEM) menunjukkan permukaan SS316L lebih halus dan tebal, dengan ketebalan salutan antara 4.9 - 8.9 μm. Pengujian menggunakan kaedah polarisasi linear Tafel dalam media 0.5 M H2 SO4 , mendapati nilai arus kakisan (Icorr) semakin menurun dengan adanya salutan iaitu dari 18.484 μA/cm2 menjadi 0.859 μA/cm2 . Kadar kakisan SS316L tanpa salutan adalah 0.7172 mpy, manakala SS316L yang disalut dengan gam arab mempunyai kadar kakisan yang lebih rendah iaitu 0.033 mpy. Dari kajian ini, keputusan menunjukkan bahawa gam arab dengan salutan EPD dapat memberikan perlindungan kakisan terhadap permukaan SS316L

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

    Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

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    Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe
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