Fourth-order discrete-time variable centre frequency bandpass sigma-delta modulator

Copyright © 2006 IEEEA design for a variable centre frequency bandpass sigma-delta modulator is presented. The modulator is based on a tunable discrete-time resonator using only one control parameter. The noise transfer function of the modulator is controlled by a 4-bit digital signal, which provides nine different centre frequencies distributed between 0.1-0.4 normalized frequencies. The measurement results show a stable modulator at all centre frequenciesY. Zhu, S.F. Al-Sarawi, C. C. Lim, and M.J. Liebel

Hybrid parallel counters - Domino and threshold logic

Copyright © 2004 IEEEParallel counters are the building blocks of partial product reduction tree (PPRT) circuits, which are required for high-performance multiplication. In this paper we will implement novel counters using a hybrid of domino and threshold logic. A test 64 × 64 PPRT using these counters was found to reduce latency by 39% and device count by 38% compared to the domino logic equivalent.Troy D. Townsend, Peter Celinski, Said F. Al-Sarawi and Michael J. Liebel

Establishing a marine monitoring programme to assess antibiotic resistance: a case study from the Gulf Cooperation Council (GCC) region

The World Health Organization considers antimicrobial resistance as one of the most pressing global issues which poses a fundamental threat to human health, development, and security. Due to demographic and environmental factors, the marine environment of the Gulf Cooperation Council (GCC) region may be particularly susceptible to the threat of antimicrobial resistance. However, there is currently little information on the presence of AMR in the GCC marine environment to inform the design of appropriate targeted surveillance activities. The objective of this study was to develop, implement and conduct a rapid regional baseline monitoring survey of the presence of AMR in the GCC marine environment, through the analysis of seawater collected from high-risk areas across four GCC states: (Bahrain, Oman, Kuwait, and the United Arab Emirates). 560 Escherichia coli strains were analysed as part of this monitoring programme between December 2018 and May 2019. Multi-drug resistance (resistance to three or more structural classes of antimicrobials) was observed in 32.5% of tested isolates. High levels of reduced susceptibility to ampicillin (29.6%), nalidixic acid (27.9%), tetracycline (27.5%), sulfamethoxazole (22.5%) and trimethoprim (22.5%) were observed. Reduced susceptibility to the high priority critically important antimicrobials: azithromycin (9.3%), ceftazidime (12.7%), cefotaxime (12.7%), ciprofloxacin (44.6%), gentamicin (2.7%) and tigecycline (0.5%), was also noted. A subset of 173 isolates was whole genome sequenced, and high carriage rates of qnrS1 (60/173) and bla CTX-M-15 (45/173) were observed, correlating with reduced susceptibility to the fluoroquinolones and third generation cephalosporins, respectively. This study is important because of the resistance patterns observed, the demonstrated utility in applying genomic-based approaches to routine microbiological monitoring, and the overall establishment of a transnational AMR surveillance framework focussed on coastal and marine environments

Outcomes and uptake of explicit research skill development across degree programs

John Willison, Said Al Sarawi, Cynthia Bottema, Susan Hazel, Ursula Henderson, Sophie Karanicolas, Clinton Kempster, Ursula McGowan, Julia Miller, Kogi Naidoo, Brian Ng, Edward Palmer, Simon Pyke, Catherine Snelling, Richard Warner, Michael Wilmore, Glen Croy, Leanne McCann, Susan Mayson, Lyn Torres, Suniti Bandaranaike, Tai Peseta, Rowena Harpe

Explicit research skill development within problem/project based learning approach

Problem/Project Based Learning is an innovative teaching model that proved to be effective in a number of disciplines. The common quality that is needed by students taught using this model, whether they are at school, vocational and training (VET) collage, undergraduate programs, and most importantly higher education degrees, is research skill development. However, the concept of skills development and how to do so is not usually clear from students' point of view, while from some educators' point of view such skills are acquired by osmosis through interaction with peers, seniors, or experienced researchers. In this paper, we demonstrate the use of the Research Skill Development (RSD) framework by educators to conceptualize an explicit development of these skills as part of their course delivery. In this paper, we propose to utilize the strengths of RSD framework with problem/project-Based Learning (PBL) to result in explicit research development, which is usually a critical component of PBL model. Pilot studies in two universities were carried out, and improvements in the technical paper quality and research outputs have been observed.Said Al-Sarawi, Mahmoud Al-Qutayri, Brian Ng and Mohammed Ismai

Secure wireless powering and interrogation of an implantable microvalve

As the power is at a premium in a wireless powered microvalve, it necessitated the design and development of a contactless powering system specific to implant functionality. We present a custom design and development of the biotelemetry system for the implanted microvalve, using FEM modelling and experimental validation in the presence of numerical and physical human body phantoms, respectively. A comprehensive 3-dimensional FEM modelling and physical validation of an inductively coupled link comprising a 6×6×0.5 mm conformal spiral implanted antenna and a 8×5×0.2 cm spiral transmitter antenna is demonstrated. In addition to the investigation of the quality factor and inductance of individual coils, an analysis of the received relative signal response of the implanted antenna is presented.Ajay C. Tikka, Michael Faulkner and Said Al-Saraw

Variable centre frequency bandpass sigma-delta modulator

© 2003 COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.In wideband surveillance and digital radio systems, there is a need to sweep the centre fequency of the data converter to detect a broadcast i nthe band of interest. Hence there is a need to design data converters with variable centre frequencies. Sigma-Delta modulators with programmable center frequency are chosen for this purpose. In this paper new resonators for a variable centre frequency bandpass Sigma-Delta modulator are presented. The new resonators have a centre frequency that extends from very low frequency up to half the sampling frequency. Simulation results of a fourth order discrete-time bandpass modulator employing the new resonator are presented using MATLAB and SPICE.Yingbo Zhu, Said F. Al-Sarawi, and Michael Liebel

A design methodology for a very low noise figure common-source LNA

©2005 COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.The design of common source (CS) Low Noise Amplifiers (LNA) for wireless receivers is presented. The design trade-offs between main criteria are discussed. An extra gate-to-source capacitor is added to the input transistor to reduce the transistor dimension while still satisfying the noise matching. The small MOSFET also improves the LNA linearity with comparatively small drain-source current. The extra gate-to-source capacitor is introduced by the bonding-pad parasitic capacitor; hence a negative effect parasitic capacitance is turned into a useful capacitor. The simulated Noise Figure (NF) of two single-ended LNAs using 0.18 µm CMOS process achieve 0.62 dB and 0.92 dB at 2.4 GHz and 5.25 GHz respectively while matching a 50 ohm impedance.Yingbo Zhu, Said F. Al-Sarawi, and Michael Liebel