2,028 research outputs found

    An evaluation of Nigerian ports post-concession performance

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    Purpose: The quest for efficiency is claimed to be the major objective of port privatisation and this has led many ports in Africa to undertake port reforms. Based on this, Nigerian ports were concessioned and operations were handed over in one scoop to private operators between 2006 and 2007. This paper is looking to investigate in the reform that took place in a very short period of time improved the performance of Nigerian ports. This paper is also looking to provide a model for future evaluation. Research Approach: A window based DEA model with panel data will be employed to measure pre- and post concession Nigerian ports' performance to determine efficiency gains from port reform. Secondly, to demonstrate how concession influence efficiency, a DEA based Malmquist productivity Insex will be used to determine the sources of (in)efficiency by decomposing the efficiency into frontier shift effects and catch-up effects. Findings and Originality: The results revealed that none of the ports is hundred percent efficient before and after concession but rather a tremendous increase in throughput and ship traffic after the reform in most of the ports. Apapa port is the most efficient while Calabar and Warri are inefficient although there were fluctuations in efficiency in all the ports. The research is inconclusive because it is still ongoing Although some studies have investigated the relationship between port efficiency and privatisation however several gaps still exist as the studies are skewed in favour of container ports in the developed world, mainly in Europe. Therefore, the need arises to critically look at the overall efficiency of national port system to enhance the efficiency of global transport chain. Research Impact: The study will contribute to existing literature on port performance being the first to evaluate the post concession performance of a major maritime player in Sub-Saharan Africa. It will contribute to the never- ending debate by the Academia on the effect of ownership or privatisation on efficiency from the perspective of port institutional reforms in the third world countries Practical Impact: It will benefit the Federal Government of Nigeria as a reference document of the first five years of the port reform policy and help the Government to intervene in areas of observed inefficiencies and make adjustments where possible. On the part of the "Landlord" NPA it will help them in the performing their regulatory role by identifying the operators who are making inefficient use of the resources allocated to them and provide the basis for future evaluation. Finally, it will give the various stake holders in the Maritime Industry a full grasp of the effect of concession in a Nation's port as Nigeria is the first country in the world to hand over terminal operations in all her ports in one scoop

    An Analytical Study for Subsonic Oblique Wing Transport Concept

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    The oblique wing concept has been investigated for subsonic transport application for a cruise Mach number of 0.95. Three different mission applications were considered and the concept analyzed against the selected mission requirements. Configuration studies determined the best area of applicability to be a commercial passenger transport mission. The critical parameter for the oblique wing concept was found to be aspect ratio which was limited to a value of 6.0 due to aeroelastic divergence. Comparison of the concept final configuration was made with fixed winged configurations designed to cruise at Mach 0.85 and 0.95. The crossover Mach number for the oblique wing concept was found to be Mach 0.91 for takeoff gross weight and direct operating cost. Benefits include reduced takeoff distance, installed thrust and mission block fuel and improved community noise characteristics. The variable geometry feature enables the final configuration to increase range by 10% at Mach 0.712 and to increase endurance by as much as 44%

    Measurement of vertical velocity using clear-air Doppler radars

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    A new clear air Doppler radar was constructed, called the Flatland radar, in very flat terrain near Champaign-Urbana, Illinois. The radar wavelength is 6.02 m. The radar has been measuring vertical velocity every 153 s with a range resolution of 750 m almost continuously since March 2, 1987. The variance of vertical velocity at Flatland is usually quite small, comparable to the variance at radars located near rough terrain during periods of small background wind. The absence of orographic effects over very flat terrain suggests that clear air Doppler radars can be used to study vertical velocities due to other processes, including synoptic scale motions and propagating gravity waves. For example, near rough terrain the shape of frequency spectra changes drastically as the background wind increases. But at Flatland the shape at periods shorter than a few hours changes only slowly, consistent with the changes predicted by Doppler shifting of gravity wave spectra. Thus it appears that the short period fluctuations of vertical velocity at Flatland are alsmost entirely due to the propagating gravity waves

    Franck-Condon Blockade in a Single-Molecule Transistor

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    We investigate vibron-assisted electron transport in single-molecule transistors containing an individual Fe4 Single-Molecule Magnet. We observe a strong suppression of the tunneling current at low bias in combination with vibron-assisted excitations. The observed features are explained by a strong electron-vibron coupling in the framework of the Franck-Condon model supported by density-functional theory

    Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plans

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    The establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the four candidates was performed and the Boeing KC-135A and the Gulfstream American Gulfstream II recommended as the most suitable aircraft for test application. Conceptual designs of the two recommended aircraft were performed and cost and schedule data for the entire testbed program were generated. The program total cost was estimated and a wind tunnel program cost and schedule is generated in support of the testbed program

    Autism and the U.K. secondary school experience

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    This research investigated the self-reported mainstream school experiences of those diagnosed on the autistic spectrum compared with the typically developing school population. Existing literature identifies four key areas that affect the quality of the school experience for students with autism: social skills, perceived relationships with teaching staff, general school functioning, and interpersonal strengths of the young person. These areas were explored in a mainstream U.K. secondary school with 14 students with autism and 14 age and gender matched students without autism, using self-report questionnaires and semi-structured interviews. Quantitative analyses showed consistent school experiences for both groups, although content analysis of interview data highlighted some differences in the ways in which the groups perceive group work, peers, and teaching staff within school. Implications for school inclusion are discussed, drawing attention to how staff awareness of autism could improve school experience and success for students with autism attending mainstream schools

    Calculation of the Coherent Synchrotron Radiation Impedance from a Wiggler

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    Most studies of Coherent Synchrotron Radiation (CSR) have only considered the radiation from independent dipole magnets. However, in the damping rings of future linear colliders, a large fraction of the radiation power will be emitted in damping wigglers. In this paper, the longitudinal wakefield and impedance due to CSR in a wiggler are derived in the limit of a large wiggler parameter KK. After an appropriate scaling, the results can be expressed in terms of universal functions, which are independent of KK. Analytical asymptotic results are obtained for the wakefield in the limit of large and small distances, and for the impedance in the limit of small and high frequencies.Comment: 10 pages, 8 figure

    Evolution of magnetic polarons and spin-carrier interactions through the metal-insulator transition in Eu1x_{1-x}Gdx_{x}O

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    Raman scattering studies as functions of temperature, magnetic field, and Gd-substitution are used to investigate the evolution of magnetic polarons and spin-carrier interactions through the metal-insulator transition in Eu1x_{1-x}Gdx_{x}O. These studies reveal a greater richness of phase behavior than have been previously observed using transport measurements: a spin-fluctuation-dominated paramagnetic (PM) phase regime for T >> T^{*} >> TC_{C}, a two-phase regime for T << T^{*} in which magnetic polarons develop and coexist with a remnant of the PM phase, and an inhomogeneous ferromagnetic phase regime for T << TC_{C}
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