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Next generation wireless communications such as 5G are expected to feature wide channel bandwidths on the order of hundreds of MHz. As bandwidths increase, circuit impairments caused by frequency dependent behaviour such as ripple and tilt in gain and group delay become more significant. PAPR of OFDM signals also increase with increasing number of sub-carriers. Transmitter circuit characterisation for the wide-band frequency response is needed to pre-compensate the signal to be transmitted. In this article, we propose a novel scheme which uses the circuit characteristics combined with the channel response to generate the keys for encrypting signals to provide an additional tier of security at the physical layer. The modulated constellation of the signal of interest is encrypted by dispersing its phases in addition to encrypting the bits using Diffie Hellman scheme. It is also shown that the method is able to reduce the PAPR of OFDM signals. This scheme is experimentally validated from end-to-end on a millimetre wave wireless link at 28.9 GHz demonstrating security against a well-positioned eavesdropper and a reduction of PAPR by 3.5 dB in a 2048 point OFDM signal with 1664 active QPSK modulated sub-carriers. [ABSTRACT FROM AUTHOR]

For the last few decades, plastics have been the material of choice for food packaging applications. Combining mechanical performance with barrier properties and transparency, plastics have been a cost-effective solution for safely distributing food produce. Unfortunately, most plastic packaging is based on a linear model where packaging is designed for single use, resulting in vast amounts of post-consumer waste being generated annually. In response to this concern, many public and private bodies globally have set ambitious sustainable development targets with the goal of reducing plastic waste. To assist in meeting these targets, the implementation of reusable packaging schemes has been suggested. These schemes aim to prolong the lifespan and worth of plastic packaging and have the potential to reduce the environmental impact of single-use plastics, provided all aspects of their design are carefully considered. One design aspect often neglected is the influence of repeated use on the properties of the packaging material. Very little literature exists investigating the effects that repeated contamination and washing can have on the material's intrinsic properties. This review article aims to comprehensively review the functions and properties of various food packaging materials to assess their suitability for reusable food packaging applications.

This paper presents a novel low-complexity technique for reducing the Peak-to-Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) systems followed by an efficient hardware co-simulation implementation of this technique by using a Xilinx system generator on a Field Programmable Gate Array (FPGA). In this technique, each subblock is interleaved with the others, and a new optimisation scheme is introduced in which the number of iterations is equal only to the number of subblocks, which results in reduced processing time and less computation that, in turn, leads to reduced complexity. Furthermore, the proposed method focuses on simplifying the required hardware resources. Thus, it can be easily combined with other simplified techniques. The simulation results demonstrate that the new technique can effectively reduce the complexity up to 98.22% compared with the new existing Partial Transmit Sequence (PTS) techniques and yield a good Bit Error Rate (BER) performance. Through the comparison of performance between simulation and hardware, it is distinctly illustrated that the designed hardware block diagram is as workable as the simulation and the difference of the result is only 0.1 dB.

As part of an ongoing search for novel molecules with therapeutic potential we examined the mediator release inhibition activity of a number of indanones and their derivatives. The aldol condensation product 18was approximately twice as potent as disodium cromoglycate as an inhibitor of compound 48/80‐stimulated histamine release from rat peritoneal mast cells. The activity of this class of dimeric indanone compound is significantly higher than controls and may represent a new class of mast cell stabilizing agents. Compound 18has been selected for further biological evaluation of its mast cell stabilization profile.

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