29,404 research outputs found

    Capital Ownership, Capital Structure and Capital Markets: Financial Constraints and the Decline of the Lancashire Cotton Textile Industry 1880-1965

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    The objective of this analysis is to provide a reinterpretation of the decline of the Lancashire cotton textile industry during the twentieth century. Its principal concerns are with the governance structure of the industry, the resultant capital structures of firms and the constraints thereby imposed on the activities of entrepreneurs. Its central thesis is that ownership of the industry, and the redistribution of ownership claims during booms and slumps, imposed pressures and constraints on decision-makers. These financial constraints dominated the strategic questions of re-equipment and modernisation

    Galvanic coupling between D6AC steel, 6061-T6 aluminum, Inconel 718 and graphite-epoxy composite material: Corrosion occurrence and prevention

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    The effects of galvanic coupling between D6AC steel, 6061-T6 aluminum, Inconel 718, and graphite-epoxy composite material (G/E) in 3.5% NaCl were studied. Measurements of corrosion potentials, galvanic currents and corrosion rates of the bare metals using weight-loss methods served to establish the need for corrosion protection in cases where D6AC steel and 6061-T6 aluminum are galvanically coupled to G/E in salt water while Inconel 718 was shown to be compatible with G/E. Six tests were made to study corrosion protective methods for eliminating galvanic corrosion in the cases of D6AC steel and 6061-T6 aluminum coupled to G/E. These results indicate that, when the G/E is completely coated with paint or a paint/polyurethane resin combination, satisfactory protection of the D6AC steel is achieved with either a coat of zinc-rich primer or a primer/topcoat combination. Likewise, satisfactory corrosion protection of the aluminum is achieved by coating it with an epoxy coating system

    Non-contact temperature measurement requirements

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    The Marshall Space Flight Center is involved with levitation experiments for Spacelab, Space Station, and drop tube/tower operations. These experiments have temperature measurement requirements, that of course must be non-contact in nature. The experiment modules involved are the Acoustic Levitator Furnace (ALF), and the Modular Electromagnetic Levitator (MEL). User requirements of the ALF and drop tube are presented. The center also has temperature measurement needs that are not microgravity experiment oriented, but rather are related to the propulsion system for the STS. This requirement will also be discussed

    An electrochemical study of the corrosion behavior of primer coated 2219-T87 aluminum

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    The corrosion behavior for 2219-T87 aluminum coated with various primers, including those used for the external tank and solid rocket boosters of the Space Shuttle Transportation System, were investigated using electrochemical techniques. Corrosion potential time, polarization resistance time, electrical resistance time, and corrosion rate time measurements were all investigated. It was found that electrical resistance time and corrosion rate time measurement were most useful for studying the corrosion behavior of painted aluminum. Electrical resistance time determination give useful information concerning the porosity of paint films, while corrosion rate time curves give important information concerning overall corrosion rates and corrosion mechanisms. In general, the corrosion rate time curves all exhibited at least one peak during the 30 day test period, which was attributed, according to the proposed mechanisms, to the onset of the hydrogen evolution reaction and the beginning of destruction of the protective properties of the paint film

    Shunt Diode Designs in Li/cf Shuttle Batteries

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    Although Li/CF cells and batteries have an excellent safety record, they are included with other battery systems that require additional safety precautions. One precaution suggested is the inclusion of shunt diodes into these batteries. The benefits of this addition are examined. All cells tested at elevated temperatures vent regardless of length of time between being fully discharged and reversed or inclusion of the diode in the system. Cells discharged at ambient temperatures all show a relatively quick reversal, but stabilize at voltages that are high enough that the diodes are not functioning. Cells tested at depressed temperatures reverse the deepest of all cells tested, with the deepest reversal occurring very early in the test and voltages recovering to above -0.60 volts near the end of the tests. Anode limited cells will eliminate the venting during hot reversal

    Real-time state of charge estimation of electrochemical model for lithium-ion battery

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    This paper proposes the real-time Kalman filter based observer for Lithium-ion concentration estimation for the electrochemical battery model. Since the computation limitation of real-time battery management system (BMS) micro-processor, the battery model which is utilized in observer has been further simplified. In this paper, the Kalman filter based observer is applied on a reduced order model of single particle model to reduce computational burden for real-time applications. Both solid phase surface lithium concentration and battery state of charge (SoC) can be estimated with real-time capability. Software simulation results and the availability comparison of observers in different Hardware-in- the-loop simulation setups demonstrate the performance of the proposed method in state estimation and real-time application

    An Equivariant Tamagawa Number Formula for Drinfeld Modules and Applications

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    We fix data (K/F,E)(K/F, E) consisting of a Galois extension K/FK/F of characteristic pp global fields with arbitrary abelian Galois group GG and a Drinfeld module EE defined over a certain Dedekind subring of FF. For this data, we define a GG-equivariant LL-function ΘK/FE\Theta_{K/F}^E and prove an equivariant Tamagawa number formula for certain Euler-completed versions of its special value ΘK/FE(0)\Theta_{K/F}^E(0). This generalizes Taelman's class number formula for the value ζFE(0)\zeta_F^E(0) of the Goss zeta function ζFE\zeta_F^E associated to the pair (F,E)(F, E). Taelman's result is obtained from our result by setting K=FK=F. As a consequence, we prove a perfect Drinfeld module analogue of the classical (number field) refined Brumer--Stark conjecture, relating a certain GG-Fitting ideal of Taelman's class group H(E/K)H(E/K) to the special value ΘK/FE(0)\Theta_{K/F}^E(0) in question

    Quantum thermometry using the ac Stark shift within the Rabi model

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    This work was supported by the EPSRC, the National Research Foundation and Ministry of Education, Singapore, and the Royal Society.A quantum two-level system coupled to a harmonic oscillator represents a ubiquitous physical system. New experiments in circuit QED and nanoelectromechanical systems (NEMS) achieve unprecedented coupling strength at large detuning between qubit and oscillator, thus requiring a theoretical treatment beyond the Jaynes-Cummings model. Here we present a new method for describing the qubit dynamics in this regime, based on an oscillator correlation function expansion of a non-Markovian master equation in the polaron frame. Our technique yields a new numerical method as well as a succinct approximate expression for the qubit dynamics. These expressions are valid in the experimentally interesting regime of strong coupling at low temperature. We obtain a new expression for the ac Stark shift and show that this enables practical and precise qubit thermometry of an oscillator.Peer reviewe
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