Multi-cell battery protection system

A multi-cell battery protection system is described wherein each cell has its own individual protective circuit. The protective circuits consist of a solid state comparator unit and a high current switching device such as a relay. The comparator units each continuously monitor the associated cell and when the cell voltage either exceeds a predetermined high level or falls below a predetermined low level, the relay is actuated whereby a bypass circuit is completed across the cell thereby effectively removing the cell from the series of cells

Observational and theoretical studies of the evolving structure of baroclinic waves

Dynamical processes involved in comma cloud formation, and passive tracer evolution in a baroclinic wave are discussed. An analytical solution was obtained demonstrating the complex nongeostrophic flow pattern involved in the redistribution of low level constituents in a finite amplitude baroclinic wave, and in the formation of the typical humidity and cloud distributions in such a wave. Observational and theoretical studies of blocking weather patterns in middle latitude flows were studied. The differences in the energy and enstrophy cascades in blocking and nonblocking situations were shown. It was established that pronounced upscale flow of both of these quantities, from intermediate to planetary scales, occurs during blocking episodes. The upscale flux of enstrophy, in particular, suggests that the persistence of blocking periods may be due to reduced dissipation of the large scale circulation and therefore entail some above normal predictability

The "Coulomb phase" in frustrated systems

The "Coulomb phase" is an emergent state for lattice models (particularly highly frustrated antiferromagnets) which have local constraints that can be mapped to a divergence-free "flux". The coarse-grained version of this flux or polarization behave analogously to electric or magnetic fields; in particular, defects at which the local constraint is violated behave as effective charges with Coulomb interactions. I survey the derivation of the characteristic power-law correlation functions and the pinch-points in reciprocal space plots of diffuse scattering, as well as applications to magnetic relaxation, quantum-mechanical generalizations, phase transitions to long-range-ordered states, and the effects of disorder.Comment: 30 pp, 5 figures (Sub. to Annual Reviews of Condensed Matter Physics

Suspension Near-Field Electrospinning: a Nanofabrication Method of Polymer Nanoarray Architectures for Tissue Engineering

Chapter 1. This chapter is divided into six sections. The first will discuss the issue of nerve tissue loss, and the strategies of therapy (1.1). The second describes the role of nanofabrication in tissue engineering (1.2). The third section details the theoretical background of electrospinning in terms of solution and process parameters (1.3). The fourth section introduces near-field electrospinning (NFES), recent advances in this field and the principles of NFES techniques (1.4). The fifth section details objectives for a tissue engineered construct for neural cell therapy, and presents possible viable solutions (1.5). The sixth summarizes the aims and structure of this thesis (1.6)..

Entropy of polydisperse chains: solution on the Bethe lattice

We consider the entropy of polydisperse chains placed on a lattice. In particular, we study a model for equilibrium polymerization, where the polydispersivity is determined by two activities, for internal and endpoint monomers of a chain. We solve the problem exactly on a Bethe lattice with arbitrary coordination number, obtaining an expression for the entropy as a function of the density of monomers and mean molecular weight of the chains. We compare this entropy with the one for the monodisperse case, and find that the excess of entropy due to polydispersivity is identical to the one obtained for the one-dimensional case. Finally, we obtain an exponential distribution of molecular weights.Comment: 5 pages, 2 figures. Reference place

Phasespace Correlations of Antideuterons in Heavy Ion Collisions

In the framework of the relativistic quantum molecular dynamics approach ({\small RQMD}) we investigate antideuteron ($\overline{d}$) observables in Au+Au collisions at 10.7~AGeV. The impact parameter dependence of the formation ratios $\overline{d}/\overline{p}^2$ and ${d}/{p}^2$ is calculated. In central collisions, the antideuteron formation ratio is predicted to be two orders of magnitude lower than the deuteron formation ratio. The $\overline{d}$ yield in central Au+Au collisions is one order of magnitude lower than in Si+Al collisions. In semicentral collisions different configuration space distributions of $\overline{p}$'s and $\overline{d}$'s lead to a large ``squeeze--out'' effect for antideuterons, which is not predicted for the $\overline{p}$'s

Families of Graphs with W_r({G},q) Functions That Are Nonanalytic at 1/q=0

Denoting $P(G,q)$ as the chromatic polynomial for coloring an $n$-vertex graph $G$ with $q$ colors, and considering the limiting function $W(\{G\},q) = \lim_{n \to \infty}P(G,q)^{1/n}$, a fundamental question in graph theory is the following: is $W_r(\{G\},q) = q^{-1}W(\{G\},q)$ analytic or not at the origin of the $1/q$ plane? (where the complex generalization of $q$ is assumed). This question is also relevant in statistical mechanics because $W(\{G\},q)=\exp(S_0/k_B)$, where $S_0$ is the ground state entropy of the $q$-state Potts antiferromagnet on the lattice graph $\{G\}$, and the analyticity of $W_r(\{G\},q)$ at $1/q=0$ is necessary for the large-$q$ series expansions of $W_r(\{G\},q)$. Although $W_r$ is analytic at $1/q=0$ for many $\{G\}$, there are some $\{G\}$ for which it is not; for these, $W_r$ has no large-$q$ series expansion. It is important to understand the reason for this nonanalyticity. Here we give a general condition that determines whether or not a particular $W_r(\{G\},q)$ is analytic at $1/q=0$ and explains the nonanalyticity where it occurs. We also construct infinite families of graphs with $W_r$ functions that are non-analytic at $1/q=0$ and investigate the properties of these functions. Our results are consistent with the conjecture that a sufficient condition for $W_r(\{G\},q)$ to be analytic at $1/q=0$ is that $\{G\}$ is a regular lattice graph $\Lambda$. (This is known not to be a necessary condition).Comment: 22 pages, Revtex, 4 encapsulated postscript figures, to appear in Phys. Rev.

Dimers on two-dimensional lattices

We consider close-packed dimers, or perfect matchings, on two-dimensional regular lattices. We review known results and derive new expressions for the free energy, entropy, and the molecular freedom of dimers for a number of lattices including the simple-quartic (4^4), honeycomb (6^3), triangular (3^6), kagome (3.6.3.6), 3-12 (3.12^2) and its dual [3.12^2], and 4-8 (4.8^2) and its dual Union Jack [4.8^2] Archimedean tilings. The occurrence and nature of phase transitions are also analyzed and discussed.Comment: Typos corrections in Eqs. (28), (32) and (43

Universities, knowledge networks and regional policy

As knowledge becomes an increasingly important part of regional innovation and development processes, the role of universities has come to the fore of regional innovation and economic development policy The objective of this paper is to critically review and assess the structure and function of knowledge networks and modes of engagement between universities and the business community in regional settings and contexts. It is argued that while regional knowledge networks and modes of engagement between universities and the business community are becoming increasingly prevalent, it is often difficult to ascribe investments in knowledge-based infrastructure to improved regional competitiveness. It is concluded that in a globalised knowledge environment the engagement between universities and regional business communities must be based on a mutual understanding of the role of both network and market-based knowledge interactions