Liquid crystals exist as a fourth state of matter. They are anisotropic and due to this order, they affect light that passes through them, making them ideal candidates for optical study. By employing a basic technique for measuring a liquid crystal’s birefringence and tilt angle, one is able to study a number of other properties such as the electroclinic effect. In addition, smectic liquid crys...

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are widely used techniques across numerous disciplines. While typically implemented at fields >1T, there has been continuous interest in the methods at much lower fields for reasons of cost, material contrast, or application. There have been numerous demonstrations of MR at much lower fields (from 1μT to 1mT), the so-called u...

Let S be a set of n ideals of a commutative ring A and let Geven (respectively Godd) denote the product of all the sums of even (respectively odd) number of ideals of S. If n ≤ 6 the product of Geven and the intersection of all ideals of S is included in Godd. In the case A is an Noetherian integral domain, this inclusion is replaced by equality if and only if A is a Dedekind domain.

The concept of a 0-distributive poset is introduced. It is shown that a section semicomplemented poset is distributive if and only if it is 0-distributive. It is also proved that every pseudocomplemented poset is 0-distributive. Further, 0-distributive posets are characterized in terms of their ideal lattices.

Ideal values of bond angles and lengths used as external restraints are crucial for the successful refinement of protein crystal structures at all but the highest of resolutions. The restraints in common use today have been designed on the assumption that each type of bond or angle has a single ideal value that is independent of context. However, recent work has shown that the ideal values are,...

An important predictor of historical sound change, functional load, fails to capture insights from speech perception. Building on ideal observer models of word recognition, we devise a new definition of functional load that incorporates both a priori expectedness and perceptual information. We explore this new measure with a simple model and find that it outperforms tra-

In this paper, in addition to some elementary facts about the ultra-groups, which their structure based on the properties of the transversal of a subgroup of a group, we focus on the relation between a group and an ultra-group. It is verified that every group is an ultra-group, but the converse is not true generally. We present the conditions under which, for every normal subultra-group of an u...

Abstract— Equivalent charge method is used to design ultra wide band asymptotic conical dipole (ACD) antenna. Combination of linear charge density and point charges is used to generate different profiles for ACD antennas. Two different profiles of ACD antenna are used as a feed for reflector based impulse-radiating antennas (IRAs). This paper focuses on the selection of ideal ACD profile as wel...

Geometrical shock dynamics, also called CCW theory, yields approximate equations for shock propagation in which only the conditions at the shock appear explicitly; the postshock flow is presumed approximately uniform and enters implicitly via a Riemann invariant. The nonrelativistic theory, formulated by G. B. Whitham and others, matches many experimental results surprisingly well. Motivated by...