Exploring the physicochemical basis of cheese texture, rheology and functionality, with emphasis on cation-casein interactions

The physicochemical properties of cheese and milk gels are greatly influenced by molecular interactions between the casein proteins involving calcium. Novel experiments were designed to investigate the relationship between insoluble caseinbound cations and rheological properties of Cheddar cheese and rennet-induced milk gels. Cheddar cheese and rennet-induced milk gels were supplemented with Mg2+ or Sr2+ to compare their effects on their rheological properties to those previously reported in literature for Ca2+ supplementation. Sr2+ displayed behaviour similar to Ca2+ as observed by its ability to increase the rigidity of cheese and rennet milk gels and also decrease cheese meltability. Mg+2 had no influence on cheese rheological properties and was greatly inferior to Ca2+ and Sr2+ in its ability to increase rennet milk gel elasticity. Cheddar cheese was supplemented with the calcium-chelating salts trisodium citrate, disodium hydrogen phosphate or disodium EDTA, in an attempt to reduce the CCP content of cheese and thereby modify its rheological and functional properties. TSC and EDTA were successful in decreasing cheese CCP, whereas DSP caused an initial increase in CCP content. Cheddar cheese was supplemented with chlorides of iron, copper and zinc at salting to investigate the effects of concentrations of these elements in excess of those found innately or commonly in fortification studies, with emphasis on mineral equilibria changes and resultant alteration of rheological properties. Zinc addition was the only added metal that significantly influenced cheese rheological properties, leading to an increase in cheese rigidity and decreased cheese melt at elevated temperatures. Gum tragacanth was used as a fat-replacer in the manufacture of reduced-fat Cheddar cheese, in an attempt to improve the rheological, functional and sensory properties of reduced-fat Cheddar. Overall, the experimental work reported in this thesis generated new knowledge and theories about how casein-mineral interactions influence rheological properties of casein systems.

Spaces of observation and obscurity: cinematic prisons of light and dark

In The Eye of Power, Foucault delineated the key concerns surrounding hospital architecture in the latter half of the eighteenth century as being the ‘visibility of bodies, individuals and things'. As such, the ‘new form of hospital' that came to be developed ‘was at once the effect and support of a new type of gaze'. This was a gaze that was not simply concerned with ways of minimising overcrowding or cross-contamination. Rather, this was a surveillance intended to produce knowledge about the pathological bodies contained within the hospital walls. This would then allow for their appropriate classification. Foucault went on to describe how these principles came to be applied to the architecture of prisons. This was exemplified for him in the distinct shape of Bentham's panopticon. This circular design, which has subsequently become an often misused synonym for a contemporary culture of surveillance, was premised on a binary of the seen and the not-seen. An individual observer could stand at the central point of the circle and observe the cells (and their occupants) on the perimeter whilst themselves remaining unseen. The panopticon in its purest form was never constructed, yet it conveys the significance of the production of knowledge through observation that became central to institutional design at this time and modern thought more broadly. What is curious though is that whilst the aim of those late eighteenth century buildings was to produce wellventilated spaces suffused with light, this provoked an interest in its opposite. The gothic movement in literature that was developing in parallel conversely took a ‘fantasy world of stone walls, darkness, hideouts and dungeons…' as its landscape (Vidler, 1992: 162). Curiously, despite these modern developments in prison design, the façade took on these characteristics. The gothic imagination came to describe that unseen world that lay behind the outer wall. This is what Evans refers to as an architectural ‘hoax'. The façade was taken to represent the world within the prison walls and it was the façade that came to inform the popular imagination about what occurred behind it. The rational, modern principles ordering the prison became conflated with the meanings projected by and onto the façade. This confusion of meanings have then been repeated and reenforced in the subsequent representations of the prison. This is of paramount importance since it is the cinematic and televisual representation of the prison, as I argue here and elsewhere, that maintain this erroneous set of meanings, this ‘hoax'.

Legal myth-making: Medea and the legal representation of the feminine ‘other'

The Law operates by, and through, the creation of ideal benchmarks of conduct that are deemed to be representative of the behavioural norm. It is in this sense that it could be contended that the Law utilises, and relies on, myths in the same way as do other disciplines, notably psycho-analysis. It is possible to go even further and argue that the use of a created narrative mythology is essential to the establishment of a defined legal benchmark of behaviour by which the female defendant is assessed, judged and punished. While mythology expresses and symbolizes cultural and political behaviour, it is the Law that embodies and prescribes punitive sanctions. This element represents a powerful literary strand in classical mythology. This may be seen, for instance, in Antigone’s appeal to the Law as justification for her conduct, as much as in Medea’s challenge to the Law though her desire for vengeance. Despite its image of neutral, objective rationality, the Law, in creating and sustaining the ideals of legally-sanctioned conduct, engages in the same literary processes of imagination, reason and emotion that are central to the creation and re-creation of myth. The (re-)presentation of the Medea myth in literature (especially in theatre) and in art, finds its echo in the theatre of the courtroom where wronged women who have refused to passively accept their place, have instead responded with violence. Consequently, the Medea myth, in its depiction of the (un)feminine, serves as a template for the Law’s judgment of ‘conventional’ feminine conduct in the roles of wife and mother. Medea is an image of deviant femininity, as is Lady Macbeth and the countless other un-feminine literary and mythological women who challenge the power of the dominant culture and its ally, the Law. These women stand opposed to the other dominant theme of both literature and Law: the conformist woman, the passive dupe, who are victims of male oppression – women such as Ariadne of Naxos and Tess of the D’Ubervilles – and who are subsequently consumed by the Law, much as Semele is consumed by the fire of Jupiter’s gaze upon her. All of these women, the former as well as the latter, have their real-life counterparts in the pages of the Law Reports. As Fox puts it, “these women have come to bear the weight of the cultural stereotypes and preconceptions about women who kill.”

Analytical Elastic Stiffness Model for 3D Woven Orthogonal Interlock Composites

This research presents the development of an analytical model to predict the elastic stiffness performance of orthogonal interlock bound 3D woven composites as a consequence of altering the weaving parameters and constituent material types. The present approach formulates expressions at the micro level with the aim of calculating more representative volume fractions of a group of elements to the layer. The rationale in representing the volume fractions within the unit cell more accurately was to improve the elastic stiffness predictions compared to existing analytical modelling approaches. The models developed in this work show good agreement between experimental data and improvement on existing predicted values by models published in literature.

Teaching and Learning Guide for 'Modern Problems of Editing...'

Companion piece to my earlier article in Literature Conmpass: 'Modern Problems of Editing: The Two Texts of Doctor Faustus'. Provides a model for a module based on the topic of that article.

Barrier height variations and interface properties of PtSi/Si structures

To study some of the interfacial properties of PtSi/Si diodes, Schottky structures were fabricated on (100) crystalline silicon substrates by conventional thermal evaporation of Pt on Si followed by annealing at different temperatures (from 400 degrees C to 700 degrees C) to form PtSi. The PtSi/n-Si diodes, all yielded Schottky barrier (SB) heights that are remarkably temperature dependent. The temperature range (20-290 K) over which the I-V characteristics were measured in the present study is broader with a much lower limit (20 K), than what is usually reported in literature. These variations in the barrier height are adequately interpreted by introducing spatial inhomogeneity into the barrier potential with a Gaussian distribution having a mean barrier of 0.76 eV and a standard deviation of 30 meV. Multi-frequency capacitance-voltage measurements suggest that the barrier is primarily controlled by the properties of the silicide-silicon interface. The forward C-V characteristics, in particular, show small peaks at low frequencies that can be ascribed to interface states rather than to a series resistance effect.

Oxidized Recombinant Human Growth Hormone That Maintains Conformational Integrity

Chemical degradations often induce changes in protein conformation and thus influence protein activity and protein stability in solutions. One difficulty in studying of chemical degradations on protein aqueous properties is to obtain sufficient amount of chemically degraded protein which is well characterized. Chemical degradation protocols that are often used may induce also conformation changes and aggregation of the protein. In this article we studied the effect of methionine oxidation on the conformation of recombinant human growth hormone (r-hGH). In literature it is reported that oxidation of methionine residues induces conformation changes on r-hGH. In our study, oxidation of r-hGH was performed by incubation with hydrogen peroxide under mild conditions. Mass spectrometry and chromatographic analysis revealed that oxidation with hydrogen peroxide resulted in more than 90% of oxidized r-hGH. By extensive spectroscopic characterizations no detectable change in conformation and aggregation of r-hGH after oxidation was found. In conclusion, mild oxidation conditions led to selective oxidation of the two more accessible methionine residues of r-hGH (Met(14) and Met(125)) and did not results in any conformation change of the protein. These findings prove that oxidation of human growth hormone does not influence protein conformation and demonstrate the importance of employing mild conditions during production of oxidized protein. (C) 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:110-122, 2011

JPEG encoder system-on-a-chip demonstrator

The design of a System-on-a-Chip (SoC) demonstrator for a baseline JPEG encoder core is presented. This combines a highly optimized Discrete Cosine Transform (DCT) and quantization unit with an entropy coder which has been realized using off-the-shelf synthesizable IP cores (Run-length coder, Huffman coder and data packer). When synthesized in a 0.35 µm CMOS process, the core can operate at speeds up to 100 MHz and contains 50 k gates plus 11.5 kbits of RAM. This is approximately 20% less than similar JPEG encoder designs reported in literature. When targeted at FPGA the core can operate up to 30 MHz and is capable of compressing 9-bit full-frame color input data at NTSC or PAL rates.

Horizontal Descemet's membrane break due to birth trauma

We report an unusual case of horizontal corneal Descemet's membrane break due to birth trauma. The patient had a difficult birth with trauma to her right eye and poor vision. However unlike the reports in literature, which describe these breaks to have a characteristic vertical or vertically oblique orientation in birth trauma, the breaks in our patient were horizontal. No other cause was found for these Descemet's breaks.

Effect of impeller speed on mechanical and dissolution properties of high-shear granules

Impeller speed is one of the most crucial process variables that affect the properties of the granules produced in a high-shear granulator. Several reports can be found in literature that discuss the influence of impeller speed on the granules size. For instance some researchers like Knight report an increase of granule size with impeller speed [1] and [2], while others (Scheaefer et al. and Ramaker et al.) observed a decrease of granules size with increasing impeller speed [3] and [4]. However there is limited work reported in literature on the effect of the impeller speed on the mechanical properties of granules. Mechanical properties are important as they affect the performance of the granules on the other downstream process such as transportation and handling. The work reported here serves to address the missing in knowledge gap regarding the influence of impeller speed on mechanical properties granules. How the granulation system responds to the changes in the impeller speeds depends on binder that is used in the process. For this reason the two extreme cases, of a low viscosity binder system and high viscosity binder system are considered in this research. For low viscosity binder system it was observed that the granule size decreased with increasing impeller speed whilst for the high viscosity binder system the opposite was observed by Knight [1]. The granule strength, the Young's modulus and yield strength of the high viscosity granules increased with increasing impeller speed where as the opposite trends were observed for the low viscosity binder granules.

Detailed validation of an automotive catalysis model using spatially resolved measurements within the catalyst substrate

Many kinetic models have appeared in literature in past decades using two main approaches: the traditional global kinetics approach, or the more complex micro-kinetics approach. Whether global or micro-kinetics, kinetic models have been based on experimental data obtained at the end of the monolith. The experimental procedure using end pipe analysis may give an accurate overview of the reaction mechanisms that occur; however, the lack of information from within the catalyst can ultimately lead to inaccuracies in the kinetic model and parameters used.

Using SpaciMS, a spatially resolved experimental technique developed at the Queen's University Belfast, information from within the catalyst can be obtained. This minimally invasive technique provides detailed information of the gas concentration and temperature profile from inside the catalytic monolith. This paper presents a kinetic model and simulations validated against experimental data obtained from three positions inside the catalyst monolith at 2, 14, and 26 mm in, using data from the SpaciMS. Also, simulations of end pipe analysis, using a commercial reactor, for the CO oxidation are presented and analyzed. The simulations presented are for varying concentrations of both CO and O2 (0.5 % and 1 % CO, 0.5 % and 2 % O2) for both the global and micro-kinetic approach.

Accounting for clean, fast and high yielding reactions under microwave conditions

Thermal reactions proceed optimally when they are rapidly heated to the highest tolerable temperature, held there for the shortest possible time and then quenched. This is explained through assessments of reaction kinetics in literature examples and models. Although presently available microwave equipment is better suited to rapid heating than resistance-heated systems, the findings do not depend upon the method of heating. Claims that microwave heated reactions proceed faster and more cleanly than their conventionally heated counterparts are valid only when comparably rapid heating and cooling cannot be obtained by conventional heating. These findings suggest that rigid adherence to the sixth principle of green chemistry, relating to the use of ambient temperature and pressure, may not always afford optimal results. © 2010 The Royal Society of Chemistry.