Segregation in a fluidized binary granular mixture: Competition between buoyancy and geometric forces

Starting from the hydrodynamic equations of binary granular mixtures, we derive an evolution equation for the relative velocity of the intruders, which is shown to be coupled to the inertia of the smaller particles. The onset of Brazil-nut segregation is explained as a competition between the buoyancy and geometric forces: the Archimedean buoyancy force, a buoyancy force due to the difference between the energies of two granular species, and two geometric forces, one compressive and the other-one tensile in nature, due to the size-difference. We show that inelastic dissipation strongly affects the phase diagram of the Brazil nut phenomenon and our model is able to explain the experimental results of Breu et al. (PRL, 2003, vol. 90, p. 01402).Comment: 5 pages, 2 figure

Information Acquisition and Investment Decisions on the Internet: An Empirical Investigation

With intensifying competition, the significance of understanding customer characteristics related to information acquisition and decision making on the Internet has increased. An understanding of customer characteristics can become a crucial element in the development and implementation of marketing strategy. This paper examines the influence of some key demographic and psychological variables on information acquisition and investment decisions on the Internet, related to mutual funds. Findings indicate that product familiarity, age, and information breadth significantly influenced information acquisition. For investment decisions on the Internet, in addition to the above-mentioned variables, sex and overconfidence was also significant

Parameters for Systems Exhibiting Local Lattice Distortions, Charge and Spin Ordering

Keeping in mind the experimental results that indicate local lattice distortions, charge and spin orderings, we have developed a phenomenological approach which allows us to describe the electronic phase diagram of cuprates and related systems in terms of few parameters.In the present work we consider a third-order parameter theory which characterize charge, spin and superconductivity orderings. We are thus led to a theory of three scalar fields. By coupling these scalars to gauge fields we are naturally led to string-like solutions, which we interpret as stripes. This ties nicely with our quantum group conjecture that 1d systems play an important role in the physics of cuprates and related materials. We show that this simple approach can give rough values for two-order parameters which can be naively be interpreted as charge and spin orderings. We also report our attempt to understand how local lattice distortions are involved and what role they play in terms of these two order parameters.Comment: 8 pages revtex, Published in AIP Conference Proceedings 554: Int. Sym. on Physics in Local Lattice Distortions, July 23-26, 200

Selection from Multivariate Normal Populations

Selection from multivariate normal population

Seismic vulnerability assessment and evaluation of high rise buildings in Islamabad

Primarily the aim of this research is to carry out seismic evaluation study of buildings structures in Islamabad in order to propose basic guidelines and suggestions for Pakistan Code. Knowing the important nature of the subject, the earthquake based organizations are serious to compile a document for seismic threatened countries and areas. It is aimed that the document will work as a guideline source for the seismic evaluation, calculation and assessment of strength, behavior and expected performance and also the safety of already existing buildings. This study is based on review of already available documents on seismic vulnerability and evaluation of present buildings at different sites is carried out in order to know the key components of this very procedure so that it can be used in Pakistan and also in other developing countries as well. This would not only be robust, safe and reliable, but also can be convenient to use within the domain of available resources. ASCE 31-03 guidelines among the available documents are considered to be a suitable and the most reliable for to be in Pakistan

Estimation of losses for adobe buildings in Pakistan

Adobe buildings are vulnerable to seismic forces. Large scale destructions and casualties have been caused due to the collapse of adobe buildings during the past earthquakes. A significant number of adobe structures exist in different parts of Pakistan, similar to other parts of the world. Since Pakistan lies in a seismic active region, it is necessary to assess the level of vulnerability of these buildings in order to estimate associated losses during a seismic event. This paper presents the results of a study which was conducted to quantify damages to adobe buildings based on their fragility curves. The adobe buildings were found to be highly vulnerable to low intensity earthquakes. The vulnerability of these buildings has been compared with the European adobe buildings. It was noted that Pakistani adobe buildings were slightly less resistant to earthquakes as compared to similar buildings in Europe. Retrofitting solutions were suggested in order to increase the seismic capacity of adobe buildings in Pakistan

Mapping Mutual Fund Investor Characteristics and Modeling Switching Behavior

Securing a mutual fund that meets investment goals is an important reason why some investors exclusively stay with a particular mutual fund and others switch funds within their fund family. This paper empirically investigates investor attitudes toward mutual funds. Our model, based on investor responses, develops an investor\u27s risk profile variable. Results indicate that regardless of whether the investors invest in nonemployer plans or in both employer and nonemployer plans, they consider their investment risk, fund performance, investment mix, and the capital base of the fund before switching funds. The model developed in this study can also assist in predicting investors\u27 switching behavior