The application of uniaxial pressure can induce elastic anisotropy in otherwise isotropic rock. We consider models based on two very different rock classes, granites and weakly consolidated granular systems. We show that these models share common underlying assumptions, that they lead to similar qualitative behavior, and that both provide a microscopic basis for elliptical anisotropy. In the granular case, we make experimentally verifiable predictions regarding the horizontally propagating modes based on the measured behavior of the vertical modes.

Most of the phenomenological studies of supersymmetry have been carried out using the so-called minimal supergravity scenario, where one assumes a universal scalar mass, gaugino mass, and trilinear coupling at M{sub GUT}. Even though this is a useful simplifying assumption for phenomenological analyses, it is rather too restrictive to accommodate a large variety of phenomenological possibilities. It predicts, among other things, that the lightest supersymmetric particle (LSP) is an almost pure B-ino, and that the {mu}-parameter is larger than the masses of the SU(2){sub L} and U(1){sub Y} gauginos. We extend the minimal supergravity framework by introducing one extra parameter: the Fayet'Iliopoulos D-term for the hypercharge U(1), D{sub Y}. Allowing for this extra parameter, we find a much more diverse phenomenology, where the LSP is {tilde {nu}}{sub {tau}}, {tilde {tau}} or a neutralino with a large higgsino content. We discuss the relevance of the different possibilities to collider signatures. The same type of extension can be done to models with the gauge mediation of supersymmetry breaking. We argue that it is not wise to impose cosmological constraints on the parameter space.

Article on acid-base indicators and transition colours and pH ranges determined in select aqueous-organic mixed solvents.

One of the principal tools of industrial ecology is life-cycle assessment which intends to improve overall economic efficiency and to minimize negative environmental impacts of products, processes, and facilities. This paper describes a general methodology for environmentally responsible assessment of these activities; it discusses some of the underlying considerations for this assessment which are accessible by rigorous quantitative analysis; and an overall economic performance metric is proposed which puts both environmental and economic considerations on a common basis. Finally, some considerations involved in this approach is introduced as a guide to environmentally sound design and management.

Accurate modeling of high-explosive systems requires detailed consideration of many different physical properties and processes: These diverse processes generally occur in localized regions of the problem. Thus the very partial differential equations used to mathematically model the problem change from one region of space and time to another. The numerical algorithms generally used to solve these equations are frequently conceived in terms of data values for physical field variables u{sup i} defined at a number of spatial points indexed by multi-integer subscripts x{sub J}, resulting in a number of discrete state variables u{sup i}{sub J}. Instead of using as the fundamental object a physical field, which naturally maps to an array, the authors imagine a small piece of space modeled for a small amount of time, a space-time ``element``. Within it, various physical processes occur at various times. Self-contained, it gives account of what happens within its borders. It cooperates with a set of neighbors that organize into meshes, which organize into problems. The authors achieve in the software model a decoupling between the where and the how and the what, lack of which historically has been the source of a great deal of the software overhead of modelling continuum …