Exact Results for the Adsorption of a Flexible Self-Avoiding Polymer Chain in Two Dimensions

We derive the exact critical couplings ($x^*, y_{\rm a}^*$), where $y_{\rm a}^*/x^* = \sqrt{1+\sqrt2} = 1.533\ldots\,$, for the polymer adsorption transition on the honeycomb lattice, along with the universal critical exponents, from the Bethe Ansatz solution of the O($n$) loop model at the special transition. Our result for the thermal scaling dimension, and thus the crossover exponent $\phi=\frac{1}{2}$, is in agreement with an earlier result based on conformal invariance arguments. Our result for the geometric scaling dimensions confirms recent conjectures that they are given by $h_{\ell+1,3}$ in the Kac formula.Comment: 11 pages, REVTEX. Minor corrections made and a new reference added to the O(n) model with mixed boundary conditions - final version for publication in Physical Review Letter

A Dual Band Belt Antenna

This paper presents an antenna structure design using a standard belt for wearable applications. The antenna arouse from a body of research work on wearable metallic structures functioning as antennas for wireless on-body networks

Diagonal KK-matrices and transfer matrix eigenspectra associated with the G2(1)G^{(1)}_2 RR-matrix

We find all the diagonal $K$-matrices for the $R$-matrix associated with the minimal representation of the exceptional affine algebra $G^{(1)}_2$. The corresponding transfer matrices are diagonalized with a variation of the analytic Bethe ansatz. We find many similarities with the case of the Izergin-Korepin $R$-matrix associated with the affine algebra $A^{(2)}_2$.Comment: 11 pages, LaTe

Convoluted double square: single layer FSS with close band spacings

A novel element provides reflection band ratios as low as 1.1. It is derived from the double square but is less demanding on printing definition. Together, the two elements offer increased flexibility in Frequency selective surface design for close band applications. Substrate loss effects are also discussed

Multi-State Logging Freeze Detection Passive RFID Tags

In this work the design and measurement of a passive UHF RFID smart tag suitable for monitoring and recording critical temperature violations in cold chain management are presented. The tag uses moving parts to detect and log different temperate states without the requirement for transceivers, memory and batteries. A simple mechanical method is proposed whereby a moving metallic plate is trapped in one of 4 possible positions by specific environmental temperatures whereby inducing a permanent state based change in the passive RFID tag response. The latched product critical temperature violations can be monitored via the read power required to turn on the tag transponder chip which differs in each state

Improving water utilization from a catchment perspective

Water management / Water scarcity / Water use efficiency / Catchment areas / Calibrations / Hydrology / Models / River basins / Participatory management / Water balance / Case studies / Asia / Africa / South Africa / Zimbabwe

Tamper Proof RFID Security Tag

In this publication we present a tamper proof long range platform tolerant uhf smart RFID tag to identify valuable or security sensitive products. The smart tag functions as platform tolerant tag but once detached from the host object, it will permanently stop to function buy rendering the RFID chip unusable. The tag substrate design for additive manufacturing, platform tolerant antenna design as well as electromagnetic performance and read range are provided

Anomalous bulk behaviour in the free parafermion Z(N)Z(N) spin chain

We demonstrate using direct numerical diagonalization and extrapolation methods that boundary conditions have a profound effect on the bulk properties of a simple $Z(N)$ model for $N \ge 3$ for which the model hamiltonian is non-hermitian. For $N=2$ the model reduces to the well known quantum Ising model in a transverse field. For open boundary conditions the $Z(N)$ model is known to be solved exactly in terms of free parafermions. Once the ends of the open chain are connected by considering the model on a ring, the bulk properties, including the ground-state energy per site, are seen to differ dramatically with increasing $N$. Other properties, such as the leading finite-size corrections to the ground-state energy, the mass gap exponent and the specific heat exponent, are also seen to be dependent on the boundary conditions. We speculate that this anomalous bulk behaviour is a topological effect.Comment: 8 pages, 8 figures, minor change