University of Westminster

About: University of Westminster is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 2944 authors who have published 8426 publications receiving 200236 citations. The organization is also known as: Westminster University & Royal Polytechnic Institution.

Controlled Delivery of Gentamicin Using Poly(3-hydroxybutyrate) Microspheres

Abstract: Poly(3-hydroxybutyrate), P(3HB), produced from Bacillus cereus SPV using a simple glucose feeding strategy was used to fabricate P(3HB) microspheres using a solid-in-oil-water (s/o/w) technique. For this study, several parameters such as polymer concentration, surfactant and stirring rates were varied in order to determine their effect on microsphere characteristics. The average size of the microspheres was in the range of 2 μm to 1.54 μm with specific surface areas varying between 9.60 m(2)/g and 6.05 m(2)/g. Low stirring speed of 300 rpm produced slightly larger microspheres when compared to the smaller microspheres produced when the stirring velocity was increased to 800 rpm. The surface morphology of the microspheres after solvent evaporation appeared smooth when observed under SEM. Gentamicin was encapsulated within these P(3HB) microspheres and the release kinetics from the microspheres exhibiting the highest encapsulation efficiency, which was 48%, was investigated. The in vitro release of gentamicin was bimodal, an initial burst release was observed followed by a diffusion mediated sustained release. Biodegradable P(3HB) microspheres developed in this research has shown high potential to be used in various biomedical applications.

Metaphor in the Literature of Organizational Analysis: A Preliminary Taxonomy and a Glimpse at a Humanities-Based Perspective:

Abstract: This paper reviews the writing on metaphor in organizational analysis. It aims to synthesize developments and draw out trends. It argues that the implications of metaphor, as spelt out by poets, philosophers and linguists, do not seem to have been considered as fully as they might have been by many writers in organizational analysis. It explores possible reasons why this might be the case and what this suggests about dominant assumptions in the field. It concludes by looking at some avenues for research that arise from the study of metaphor from a more humanities-based perspective. (Reprinted by permission of Sage Publications Ltd from Inns, Dawn (2002) Metaphor in the literature of organizational analysis: a preliminary taxonomy and a glimpse at a humanities-based perspective. © 2002 SAGE Publications).

Strategies for Large-scale Production of Polyhydroxyalkanoates

Abstract: Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible intracellular polyesters that are accumulated as energy and carbon reserves by bacterial species, under nutrient limiting conditions. Successful large-scale production of PHAs is dependent on three crucial factors, which include the cost of substrate, downstream processing cost, and process development. In this respect, design and implementation of bioprocess strategies for efficient PHA bioconversions enable high PHA concentrations, yields and productivities. Additionally, development of PHA fermentation processes using inexpensive substrates, such as agro-industrial wastes, facilitates further cost reduction, thus benefitting large-scale PHA production. Thus, the aim of this review is to highlight various bioprocess strategies for high production of PHAs and their novel copolymers in relatively large quantities. This review also discusses the application of kinetic analysis and mathematical modelling as important tools for process optimization and thus improvement of the overall process economics for large-scale production of PHAs.

Design of a 0.8 Volt fully differential CMOS OTA using the bulk-driven technique

Abstract: This paper explores and presents the possible approaches to the design of a low-voltage operational transconductance amplifier (OTA) using the bulk-driven technique. The design of a 0.8 V fully differential folded-cascode OTA using a 0.35 /spl mu/m CMOS technology having a threshold voltage of 0.6 V is presented. This OTA utilizes bulk-driven differential-pairs to achieve rail-to-rail input operation, and gate- and bulk-biased cascode transistors to increase the output resistance. A continuous-time common-mode feedback (CMFB) is used for this OTA, which implements the bulk-driven differential pairs to sense the common-mode voltage smaller than the transistor's threshold voltage, as well as bulk-driven current mirrors to reduce voltage headroom consumption. This OTA has been designed using Alcatel's 0.35 /spl mu/m twin-well CMOS technology, and the simulation results indicate an open-loop gain>60 dB, unity gain-bandwidth=3.4 MHz with a 5 pF load, and an input common mode range (ICMR) of 0.8 V.