1,104 research outputs found
Glassy Aging with Modified Kohlrausch-Williams-Watts Form
In this report we address the question whether aging in the non equilibrium
glassy state is controlled by the equilibrium alpha-relaxation process which
occur at temperatures above Tg. Recently Lunkenheimer et. al. [Phys. Rev. Lett.
95, 055702 (2005)] proposed a model for the glassy aging data of dielectric
relaxation using a modified Kohlrausch-Williams-Watts (KWW) form. The aging
time dependence of the relaxation time is defined by these authors through a
functional relation involving the corresponding frequency but the stretching
exponent is same as the alpha-relaxation stretching exponent. We present here
an alternative functional form directly involving the relaxation time itself.
The proposed model fits the data of Lunkenheimer et. al. perfectly with a
stretching exponent different from the alpha-relaxation stretching exponent.Comment: 1 TeX file, 10 eps figure
Problems faced by low carbon ferroalloy industry in India
Production of Low Carbon Ferro alloys by Thermit process started in India in an organised manner around 20 years back under the sponsorship of Iron & Steel control and the able technical guidance of the National Metallurgical Labo-ratory, Jamshedpur. But unfortunately, the promise, which was envisaged at the beginning, has remained largely unfulfilled till today. The passage of this industry all these years since its inception has been chequered and
the industry is under severe strain now. An attempt has been made in this paper to enumerate some of the problems that are facing the low carbon ferro alloy industry. Possible solutions for some of the problems have also been suggested for the survival of this industry
Privatization, Yardstick Competition and Employment Dynamics: Evidence from Bangladesh
We analyze the dynamics of public and private sector employment, using the natural experiment provided by the partial privatization of the Bangladeshi jute industry. A differences-in-differences approach allows us to infer ownership effects. Although the public sector had substantial excess employment of workers initially, this excess was substantially eroded by the end of the period we study. This finding is consistent with the idea that the central authorities, which were increasingly financially constrained, used yardstick competition to reduce public sector managerial rents. The extent of such erosion differs between white-collar and manual worker categories, with excess employment persisting only in the former.
Plasticity-Induced Magnetization in Amorphous Magnetic Solids
Amorphous magnetic solids, like metallic glasses, exhibit a novel effect: the
growth of magnetic order as a function of mechanical strain under athermal
conditions in the presence of a magnetic field. The magnetic moment increases
in steps whenever there is a plastic event. Thus plasticity induces the
magnetic ordering, acting as the effective noise driving the system towards
equilibrium. We present results of atomistic simulations of this effect in a
model of a magnetic amorphous solid subjected to pure shear and a magnetic
field. To elucidate the dependence on external strain and magnetic field we
offer a mean-field theory that provides an adequate qualitative understanding
of the observed phenomenon
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