835 research outputs found

    KAM-tori near an analytic elliptic fixed point

    Full text link
    We study the accumulation of an elliptic fixed point of a real analytic Hamiltonian by quasi-periodic invariant tori. We show that a fixed point with Diophantine frequency vector \o_0 is always accumulated by invariant complex analytic KAM-tori. Indeed, the following alternative holds: If the Birkhoff normal form of the Hamiltonian at the invariant point satisfies a R\"ussmann transversality condition, the fixed point is accumulated by real analytic KAM-tori which cover positive Lebesgue measure in the phase space (in this part it suffices to assume that \o_0 has rationally independent coordinates). If the Birkhoff normal form is degenerate, there exists an analytic subvariety of complex dimension at least d+1d+1 passing through 0 that is foliated by complex analytic KAM-tori with frequency ω0\omega_0. This is an extension of previous results obtained in \cite{EFK} to the case of an elliptic fixed point

    Almost reducibility for finitely differentiable SL(2,R)-valued quasi-periodic cocycles

    Full text link
    Quasi-periodic cocycles with a diophantine frequency and with values in SL(2,R) are shown to be almost reducible as long as they are close enough to a constant, in the topology of k times differentiable functions, with k great enough. Almost reducibility is obtained by analytic approximation after a loss of differentiability which only depends on the frequency and on the constant part. As in the analytic case, if their fibered rotation number is diophantine or rational with respect to the frequency, such cocycles are in fact reducible. This extends Eliasson's theorem on Schr\"odinger cocycles to the differentiable case

    Repurposing of Offshore Oil and Gas Cables for Renewable Generation: Feasibility and Conceptual Qualification

    Get PDF
    Wind farms are expected to be deployed in the North Sea in increasing numbers and at ever greater distances from land, over the coming decades. Many nearby oil and gas fields have reached or are near the end of their lifespans, and their operators are eager to explore innovative ways to reduce decommissioning costs. One possibility would be to repurpose some of their infrastructures for use by wind farms, which would both delay decommissioning and reduce the wind farm capital costs. This paper investigates the potential for repurposing existing submarine power cores in decommissioned oil and gas fields as transmission cables for offshore renewables. Offshore power cables generally have longer lifetimes than are needed to deplete hydrocarbon reservoirs. Cable transmission capacity could be too low to provide the main connection to wind farms, but there is scope to increase capacity or use cables as auxiliary connections. A qualification methodology is proposed to assess whether existing cables might be usefully repurposed. Repurposing cables has an impact on renewable project capital expenditure (CAPEX) and levelised cost of energy (LCOE), it also positively affects decommissioning cost and the environment. The qualification methodology provides a cost-effective initial appraisal prior to field testing

    Experiences modelling and using object-oriented telecommunication service frameworks in SDL

    Get PDF
    This paper describes experiences in using SDL and its associated tools to create telecommunication services by producing and specialising object-oriented frameworks. The chosen approach recognises the need for the rapid creation of validated telecommunication services. It introduces two stages to service creation. Firstly a software expert produces a service framework, and secondly a telecommunications ‘business consultant' specialises the framework by means of graphical tools to rapidly produce services. Here the focus is given to the underlying technology required. In particular, the advantages and disadvantages of SDL and tools for this purpose are highlighted

    Synthesis, Characterization, And Antibacterial Activities Of Manganese (II), Cobalt(II), Iron (II), Nickel (II) , zinc (II) And Cadmium(II) Mixed- Ligand Complexes Containing Amino Acid(L-Valine) And Saccharin

    Get PDF
    A new six mixed ligand complexes of some transition metal ions Manganese (II), Cobalt(II), Iron (II), Nickel (II) , and non transition metal ion zinc (II) And Cadmium(II) with L-valine (Val H ) as a primary ligand and Saccharin (HSac)  as a secondary ligands  have been prepared. All the prepared complexes have been characterized by molar conductance, magnetic susceptibility infrared, electronic spectral, Elemental microanalysis (C.H.N) and AA . The complexes with the formulas   [M(Val)2(HSac)2] M= Mn (II) , Fe (II) , Co(II) ,Ni(II), Cu (II),Zn(II) and  Cd(II) L- Val H= (C5H11NO2)  , C7H5NO3S   The study shows that these complexes have octahedral geometry; The metal complexes have been screened for their in microbiological activities against bacteria.  Based on the reported results, it may be concluded that the deprotonated ligand  (L-valine) to (valinate ion (Val-)  by using (Na OH) coordinated to metal ions as bidentate ligand through the oxygen atom of the carboxylate group(-COO-), and the nitrogen atom of the amine group (NH2), where the saccharin (H Sac) coordinated as a monodentate through the nitrogen atom. Keywords: L-Valine , mixed ligand complexes, Saccharin  , spectral studies , Antibacterial activities.

    Synthesis ,characterization and antibacterial activity of mixed ligand complexes of some metals with 1-nitroso-2-naphthol and L-phenylalanine

    Get PDF
    The mixed ligand complexes of Mn(II),Fe(II),Co(II),Ni(II),Cu(II), Zn(II) and Cd (II) with 1-nitroso-2-naphthol (C10H7NO2), symbolized (NNPhH)] and amino acid L-phenylalanine( C9H10NO2), symbolized (phe H),  were synthesized and characterized by: Melting points, Solubility, Molar conductivity. determination the percentage of the metal in the complexes by flame(AAS), Molecular weight determined by  Rast’s Camphor method, susceptibility measurements, Spectroscopic Method [FT-IR and UV-Vis], And Program  [Chem office– CS .Chem.– 3D pro 2006] was used for draw compounds . The results showed that the deprotonated   two  ligands acts as a bidentate ligand ,  (phe-) was coordinated to the metal ions through the oxygen  of  the  carboxylic  group  and  the nitrogen of the amine and  the 1-nitroso-2-naphthol ligand was coordinated to the metal ions through the oxygen and nitrogen atoms. The electronic absorption spectra and magnetic susceptibility measurements of the complexes indicate octahedral geometry for all the complexes. Key words: phenyl alanine , amino acid) Complexes ,  1-nitroso-2-naphthol  ,mixed ligands   and Antibacterial     Activitie

    Analysis and Assessment of Essential Toxic Heavy Metals, PH and EC in Ishaqi River and Adjacent Soil

    Get PDF
    This research was conducted to determine content levels of heavy metal pollution.  Samples taken from Ishaqi River bank and adjacent agricultural soils area, in ten sites, distributed along 48 km of the Ishaqi River, north Baghdad. The evaluated metals were Zinc, Copper, Manganese, Iron, Cobalt, Nickel, Chromium, Cadmium, Vanadium and Lead. PH and Electric Conductivity (EC) were measured to evaluate the acidity and (EC). Results showed that most site were contaminated with metals evaluated. Among these metals, Zn, Mn, Fe and Ni were consistently higher in all the samples (both river bank and adjacent soil) followed by PB, CU, V, Cd, Co and Cr. The level concentrations of river bank were almost higher than that of adjacent soil. As will be reported later, the concentrations of Nickel, Zinc, Manganese and Iron in river bank and agricultural adjacent soil were over the permissible levels. The average mean levels were (Ni 66.36 mg/kg, Zn 42.59 mg/kg, Mn 26.78 mg/kg, Fe 25.15 mg/kg) in river bank and (Ni 46.31 mg/kg, Zn 33.06 mg/kg, Mn 20.78 mg/kg Fe 16.28 mg/kg) in agricultural adjacent soil. Overall, Nickel had the highest concentrations in the ecosystem. Keywords: heavy metals, environmental pollution, river bank, adjacent soil, AAS

    Investigating the Impact of Changing the Usage Type of Existing Structure Using BIM

    Get PDF
    Many real estate owners change the building in terms of the type of usage in response to changes in economic conditions and the requirements of the surrounding environment to get the best potential financial return. To investigate the possibilities of changing the real estate's usage, the owners of these existing structures turned to feasibility study experts for assistance in making the optimum alternatives. So, they need an integrated model between VE and BIM, especially applicable to an existing structure, to determine the optimum usage type for the existing structure. Value Engineering (VE) and Building Information Modeling (BIM) must be connected to profit from both outputs simultaneously. Previous studies only investigated the VE alternatives during the design phase; when they decided to reduce project costs by using construction materials alternatives, they ignored existing structure alternatives significantly when changing the usage type. This study attempts to provide an integrated model between VE and BIM that can be applied to the existing structure to assist in determining the best alternative in terms of the type of usage for such existing structures by conducting BIM methodology such as a feasibility study, including BIM software such as Revit and Primavera. A feasibility study that contains the bank rate of interest. As a result, the maximum financial return is obtained based on predetermined criteria and in compliance with decision-making requirements. Doi: 10.28991/CEJ-2022-08-08-06 Full Text: PD

    Lead, Nickel, Copper, Cadmium and Zinc concentrations in airborne particulates and Lead in Blood, in Al- Tarmiayh city, north Baghdad-Iraq

    Get PDF
    The concentrations of lead, nickel, copper, cadmium and zinc in airborne particulates and lead in blood, have been measured in the area of Tarmiya, during a period of one year 2011.The air pollution levels caused by these elements are still in somehow comparatively medium or low. Concerning the Pb concentrations in blood from different groups of individuals, the levels do not exceed the safe limits. And we distinguish the groups of elements and stations by using multidimensional scaling (MDS)

    Tracing and Analysis of Manganese, Nickel, Cadmium ,Copper, zinc , Lead And Aluminum Concentration and PH Values In Iraqi Chewing Gums

    Get PDF
    Evaluation of trace elements in Iraqi chewing gums are unavailable, particularly pollution of toxic elements, materials which change the values of PH in the Oral. Atomic Absorption Spectroscopy (AAS) were successfully employed to determine the concentration of 7 trace elements (essentially toxic and nonessential) and the PH, in thirteen different brands of chewing gum generally consumed in Iraq. Combined wet and dry digestion procedures were applied. Two types of heated graphite tubes were used, coated and uncoated tubes treated with tungsten solution. Result showed that Cu, Al and Zn were at very high levels in almost all brands whereas Mn was found to be high in brands A and O only. Keywords: Trace metals – heavy elements, Chewing gums - AAS-  Baghdad – Iraq
    corecore