3,431 research outputs found

    Crease Formation in the Processing of Thin Web Material

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    A mathematical model is developed to describe the conditions for buckling of steel strip between transport rolls due to strip camber, together with conditions necessary for the subsequent “ironing-in” of the buckle as it passes over the downstream roll. For a permanent crease to form, the buckle must be sufficiently stable so that it is prohibited by friction to spread laterally, and the stresses from the buckle defect must be large enough for plastic deformation to occur as it travels over the downstream roll. Once the conditions to produce a permanent crease are known they can be avoided in plant operations

    Lifting of Steel Coils in Bore-Vertical Orientation

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    Lifting of coils with the bore in the vertical orientation could give rise to safety issues if the coil integrity is compromised during the slitting and packing operation. Coil telescoping (whereby the inner wraps of the coil spiral out) is known to occur during lifting, which could pose as a serious threat to the safety of personnel involved. In this type of incident, the coil straps are also broken when their breaking strength is exceeded and the whole coil would unwrap itself at an elevated position. Back tension is applied to the strip while shearing wide strip into narrower slits; this allows sufficient radial pressure to be built up within the bulk of the narrow coils. Upon unloading, the radial pressures at the innermost and outermost wraps decrease to zero but the bulk of the inter-wrap pressure within the coil remains largely unchanged. The interwrap frictional forces developed within the coil enable the coil to retain its integrity under its own weight. It is found that the radial pressures developed within the slit coil play the most crucial role in providing sufficient frictional resistance to support the weight of the coil wraps during lifting with the bore in the vertical orientation. In addition, the inter-wrap pressures near the footprint of the mechanical lifting device, near the bore, have the most significant influence in preventing coil telescoping

    Quantum Communications with Compressed Decoherence Using Bright Squeezed Light

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    We propose a scheme for long-distance distribution of quantum entanglement in which the entanglement between qubits at intermediate stations of the channel is established by using bright light pulses in squeezed states coupled to the qubits in cavities with a weak dispersive interaction. The fidelity of the entanglement between qubits at the neighbor stations (10 km apart from each other) obtained by postselection through the balanced homodyne detection of 7 dB squeezed pulses can reach F=0.99 without using entanglement purification, at same time, the probability of successful generation of entanglement is 0.34.Comment: 4 pages, 2 figure

    On the Heat Transfer of a loving Composite Strip Compressed by Two Rotating Cylinders

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    Two influential parameters in rolling mil

    Fermented pumpkin-based beverage inhibits key enzymes of carbohydrate digesting and extenuates postprandial hyperglycemia in type-2 diabetic rats

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    A novel functional pumpkin-based beverage fermented by Lactobacillus mali K8 (FPJ) was produced. FPJ possessed higher ferric reducing antioxidant power (FRAP, 270.76 μM TE/100 ml) and radical scavenging activity (RSA‒IC50, 7.56 mg ml‒1) compared with non-inoculated control (PJ) (102.99 μM TE/100 ml and IC50 52.78 mg ml‒1). Up to an IC50 of 23.71 and 5.27 mg ml‒1 of α-amylase and α-glucosidase inhibitions were demonstrated by FPJ, close to that of acarbose (IC50 4.86 and 0.048 mg ml‒1, respectively). Oral administration of FPJ significantly lowered post-meal blood glucose levels in low-dose streptozotocin (STZ) and high-fat diet-treated rat – a reduction of incremental areas under the curve 2334 versus 2689 mmol min l‒1. Thus, it may open new dietary measure in managing postprandial hyperglycaemia

    A matched solution method for the prediction of residual stresses for flat rolling

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    Steel strip must meet tight dimensional tolerances as well as having good `flatness' such that the strip is planar when not subject to external forces. This latter attribute demands extremely small residual stresses. A computational model is developed to describe the lateral variations of the magnitude and direction of the plastic deformation of the strip during rolling, together with the corresponding strip stresses and the degree of elastic roll flattening. In addition the downstream lateral variation in longitudinal strains, and resultant stresses, are calculated. From these the strip flatness can be predicted. It was found that for thin, wide strip the procedure became numerically unstable. This was overcome by developing an analytical solution for the simpler rolling conditions, away from the strip edge, and iteratively matching this solution to the numerical solution found for the edge region. This provided a more stable solution procedure

    On some developments and evaluation of an Eulerian-Lagrangian method for the transport equation

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    The modelling of typical engineering problems in industry, such as water-jet cooling of hot-rolled steel strip products, directly involves the solution of a transport (advection-diffusion) equation for the cooling characteristics of the strip. The non-linear nature of the heat conduction involved aggravates the difficulty of the problem. Traditional Finite Difference techniques for the solution of this advection dominated transport equation incur severe Courant number stability restrictions as well as instabilities in the presence of temperature discontinuities. Eulerian-Lagrangian Methods (ELM's) solve the transport equation in Lagrangian form `along' backward characteristics effectively decoupling the advection and diffusion terms but retaining the convenience of fixed computational grids. Typical interpolation methods used to obtain the values at the feet of characteristic lines lead to spurious oscillations, numerical diffusion, peak clipping and phase errors. Through the use of `peak tracking', by the forward-tracking of Eulerian nodal points, this paper attempts to alleviate these errors. A comparison of 1-D benchmark tests from the Convection-Diffusion Forum as well as appropriate error measures, are shown to produce appreciable improvements over the standard methods for a range of time steps, very large Peclet numbers and Courant numbers in excess of one
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